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![Gabriel Knezek](/assets/img/avatar_default.png)
When userspace requests a GPIO v1 line info changed event,
lineinfo_watch_read() populates and returns the gpioline_info_changed
structure. It contains 5 words of padding at the end which are not
initialized before being returned to userspace.
Zero the structure in gpio_v2_line_info_change_to_v1() before populating
its contents.
Fixes: aad955842d
("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Signed-off-by: Gabriel Knezek <gabeknez@linux.microsoft.com>
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2378 lines
60 KiB
C
2378 lines
60 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/anon_inodes.h>
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#include <linux/atomic.h>
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#include <linux/bitmap.h>
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#include <linux/build_bug.h>
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#include <linux/cdev.h>
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#include <linux/compat.h>
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#include <linux/compiler.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/file.h>
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#include <linux/gpio.h>
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#include <linux/gpio/driver.h>
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#include <linux/interrupt.h>
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#include <linux/irqreturn.h>
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#include <linux/kernel.h>
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#include <linux/kfifo.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/poll.h>
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#include <linux/spinlock.h>
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#include <linux/timekeeping.h>
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#include <linux/uaccess.h>
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#include <linux/workqueue.h>
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#include <uapi/linux/gpio.h>
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#include "gpiolib.h"
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#include "gpiolib-cdev.h"
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/*
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* Array sizes must ensure 64-bit alignment and not create holes in the
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* struct packing.
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*/
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static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2));
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static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8));
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/*
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* Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility
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*/
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8));
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8));
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/* Character device interface to GPIO.
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*
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* The GPIO character device, /dev/gpiochipN, provides userspace an
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* interface to gpiolib GPIOs via ioctl()s.
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*/
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/*
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* GPIO line handle management
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*/
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#ifdef CONFIG_GPIO_CDEV_V1
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/**
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* struct linehandle_state - contains the state of a userspace handle
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* @gdev: the GPIO device the handle pertains to
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* @label: consumer label used to tag descriptors
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* @descs: the GPIO descriptors held by this handle
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* @num_descs: the number of descriptors held in the descs array
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*/
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struct linehandle_state {
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struct gpio_device *gdev;
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const char *label;
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struct gpio_desc *descs[GPIOHANDLES_MAX];
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u32 num_descs;
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};
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#define GPIOHANDLE_REQUEST_VALID_FLAGS \
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(GPIOHANDLE_REQUEST_INPUT | \
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GPIOHANDLE_REQUEST_OUTPUT | \
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GPIOHANDLE_REQUEST_ACTIVE_LOW | \
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GPIOHANDLE_REQUEST_BIAS_PULL_UP | \
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GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \
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GPIOHANDLE_REQUEST_BIAS_DISABLE | \
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GPIOHANDLE_REQUEST_OPEN_DRAIN | \
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GPIOHANDLE_REQUEST_OPEN_SOURCE)
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static int linehandle_validate_flags(u32 flags)
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{
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/* Return an error if an unknown flag is set */
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if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
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return -EINVAL;
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/*
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* Do not allow both INPUT & OUTPUT flags to be set as they are
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* contradictory.
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*/
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if ((flags & GPIOHANDLE_REQUEST_INPUT) &&
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(flags & GPIOHANDLE_REQUEST_OUTPUT))
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return -EINVAL;
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/*
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* Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
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* the hardware actually supports enabling both at the same time the
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* electrical result would be disastrous.
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*/
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if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
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(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
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return -EINVAL;
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/* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
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if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) &&
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((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
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(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
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return -EINVAL;
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/* Bias flags only allowed for input or output mode. */
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if (!((flags & GPIOHANDLE_REQUEST_INPUT) ||
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(flags & GPIOHANDLE_REQUEST_OUTPUT)) &&
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((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
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return -EINVAL;
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/* Only one bias flag can be set. */
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if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
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(flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
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GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
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((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
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return -EINVAL;
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return 0;
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}
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static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp)
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{
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assign_bit(FLAG_ACTIVE_LOW, flagsp,
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lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW);
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assign_bit(FLAG_OPEN_DRAIN, flagsp,
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lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN);
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assign_bit(FLAG_OPEN_SOURCE, flagsp,
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lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE);
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assign_bit(FLAG_PULL_UP, flagsp,
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lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP);
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assign_bit(FLAG_PULL_DOWN, flagsp,
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lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN);
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assign_bit(FLAG_BIAS_DISABLE, flagsp,
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lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE);
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}
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static long linehandle_set_config(struct linehandle_state *lh,
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void __user *ip)
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{
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struct gpiohandle_config gcnf;
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struct gpio_desc *desc;
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int i, ret;
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u32 lflags;
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if (copy_from_user(&gcnf, ip, sizeof(gcnf)))
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return -EFAULT;
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lflags = gcnf.flags;
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ret = linehandle_validate_flags(lflags);
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if (ret)
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return ret;
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for (i = 0; i < lh->num_descs; i++) {
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desc = lh->descs[i];
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linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags);
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/*
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* Lines have to be requested explicitly for input
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* or output, else the line will be treated "as is".
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*/
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if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
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int val = !!gcnf.default_values[i];
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ret = gpiod_direction_output(desc, val);
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if (ret)
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return ret;
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} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
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ret = gpiod_direction_input(desc);
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if (ret)
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return ret;
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}
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blocking_notifier_call_chain(&desc->gdev->notifier,
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GPIO_V2_LINE_CHANGED_CONFIG,
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desc);
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}
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return 0;
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}
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static long linehandle_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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struct linehandle_state *lh = file->private_data;
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void __user *ip = (void __user *)arg;
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struct gpiohandle_data ghd;
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DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
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int i;
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if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
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/* NOTE: It's ok to read values of output lines. */
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int ret = gpiod_get_array_value_complex(false,
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true,
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lh->num_descs,
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lh->descs,
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NULL,
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vals);
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if (ret)
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return ret;
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memset(&ghd, 0, sizeof(ghd));
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for (i = 0; i < lh->num_descs; i++)
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ghd.values[i] = test_bit(i, vals);
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if (copy_to_user(ip, &ghd, sizeof(ghd)))
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return -EFAULT;
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return 0;
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} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
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/*
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* All line descriptors were created at once with the same
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* flags so just check if the first one is really output.
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*/
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if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
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return -EPERM;
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if (copy_from_user(&ghd, ip, sizeof(ghd)))
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return -EFAULT;
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/* Clamp all values to [0,1] */
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for (i = 0; i < lh->num_descs; i++)
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__assign_bit(i, vals, ghd.values[i]);
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/* Reuse the array setting function */
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return gpiod_set_array_value_complex(false,
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true,
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lh->num_descs,
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lh->descs,
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NULL,
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vals);
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} else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) {
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return linehandle_set_config(lh, ip);
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}
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return -EINVAL;
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}
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#ifdef CONFIG_COMPAT
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static long linehandle_ioctl_compat(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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return linehandle_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
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}
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#endif
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static void linehandle_free(struct linehandle_state *lh)
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{
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int i;
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for (i = 0; i < lh->num_descs; i++)
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if (lh->descs[i])
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gpiod_free(lh->descs[i]);
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kfree(lh->label);
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put_device(&lh->gdev->dev);
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kfree(lh);
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}
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static int linehandle_release(struct inode *inode, struct file *file)
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{
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linehandle_free(file->private_data);
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return 0;
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}
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static const struct file_operations linehandle_fileops = {
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.release = linehandle_release,
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.owner = THIS_MODULE,
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.llseek = noop_llseek,
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.unlocked_ioctl = linehandle_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = linehandle_ioctl_compat,
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#endif
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};
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static int linehandle_create(struct gpio_device *gdev, void __user *ip)
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{
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struct gpiohandle_request handlereq;
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struct linehandle_state *lh;
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struct file *file;
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int fd, i, ret;
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u32 lflags;
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if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
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return -EFAULT;
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if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
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return -EINVAL;
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lflags = handlereq.flags;
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ret = linehandle_validate_flags(lflags);
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if (ret)
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return ret;
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lh = kzalloc(sizeof(*lh), GFP_KERNEL);
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if (!lh)
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return -ENOMEM;
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lh->gdev = gdev;
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get_device(&gdev->dev);
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if (handlereq.consumer_label[0] != '\0') {
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/* label is only initialized if consumer_label is set */
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lh->label = kstrndup(handlereq.consumer_label,
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sizeof(handlereq.consumer_label) - 1,
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GFP_KERNEL);
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if (!lh->label) {
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ret = -ENOMEM;
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goto out_free_lh;
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}
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}
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lh->num_descs = handlereq.lines;
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/* Request each GPIO */
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for (i = 0; i < handlereq.lines; i++) {
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u32 offset = handlereq.lineoffsets[i];
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struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset);
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if (IS_ERR(desc)) {
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ret = PTR_ERR(desc);
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goto out_free_lh;
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}
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ret = gpiod_request(desc, lh->label);
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if (ret)
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goto out_free_lh;
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lh->descs[i] = desc;
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linehandle_flags_to_desc_flags(handlereq.flags, &desc->flags);
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ret = gpiod_set_transitory(desc, false);
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if (ret < 0)
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goto out_free_lh;
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/*
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* Lines have to be requested explicitly for input
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* or output, else the line will be treated "as is".
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*/
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if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
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int val = !!handlereq.default_values[i];
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ret = gpiod_direction_output(desc, val);
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if (ret)
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goto out_free_lh;
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} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
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ret = gpiod_direction_input(desc);
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if (ret)
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goto out_free_lh;
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}
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blocking_notifier_call_chain(&desc->gdev->notifier,
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GPIO_V2_LINE_CHANGED_REQUESTED, desc);
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dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
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offset);
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}
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fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
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if (fd < 0) {
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ret = fd;
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goto out_free_lh;
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}
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file = anon_inode_getfile("gpio-linehandle",
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&linehandle_fileops,
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lh,
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O_RDONLY | O_CLOEXEC);
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if (IS_ERR(file)) {
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ret = PTR_ERR(file);
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goto out_put_unused_fd;
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}
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handlereq.fd = fd;
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if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
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/*
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* fput() will trigger the release() callback, so do not go onto
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* the regular error cleanup path here.
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*/
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fput(file);
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put_unused_fd(fd);
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return -EFAULT;
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}
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fd_install(fd, file);
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dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
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lh->num_descs);
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return 0;
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out_put_unused_fd:
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put_unused_fd(fd);
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out_free_lh:
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linehandle_free(lh);
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return ret;
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}
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#endif /* CONFIG_GPIO_CDEV_V1 */
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/**
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* struct line - contains the state of a requested line
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* @desc: the GPIO descriptor for this line.
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* @req: the corresponding line request
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* @irq: the interrupt triggered in response to events on this GPIO
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* @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or
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* GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied
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* @timestamp_ns: cache for the timestamp storing it between hardirq and
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* IRQ thread, used to bring the timestamp close to the actual event
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* @req_seqno: the seqno for the current edge event in the sequence of
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* events for the corresponding line request. This is drawn from the @req.
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* @line_seqno: the seqno for the current edge event in the sequence of
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* events for this line.
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* @work: the worker that implements software debouncing
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* @sw_debounced: flag indicating if the software debouncer is active
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* @level: the current debounced physical level of the line
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*/
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struct line {
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struct gpio_desc *desc;
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/*
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* -- edge detector specific fields --
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*/
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struct linereq *req;
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unsigned int irq;
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/*
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* eflags is set by edge_detector_setup(), edge_detector_stop() and
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* edge_detector_update(), which are themselves mutually exclusive,
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* and is accessed by edge_irq_thread() and debounce_work_func(),
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* which can both live with a slightly stale value.
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*/
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u64 eflags;
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/*
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* timestamp_ns and req_seqno are accessed only by
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* edge_irq_handler() and edge_irq_thread(), which are themselves
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* mutually exclusive, so no additional protection is necessary.
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*/
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u64 timestamp_ns;
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u32 req_seqno;
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/*
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* line_seqno is accessed by either edge_irq_thread() or
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* debounce_work_func(), which are themselves mutually exclusive,
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* so no additional protection is necessary.
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*/
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u32 line_seqno;
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/*
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* -- debouncer specific fields --
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*/
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struct delayed_work work;
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/*
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* sw_debounce is accessed by linereq_set_config(), which is the
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* only setter, and linereq_get_values(), which can live with a
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* slightly stale value.
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*/
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unsigned int sw_debounced;
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/*
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* level is accessed by debounce_work_func(), which is the only
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* setter, and linereq_get_values() which can live with a slightly
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* stale value.
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*/
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unsigned int level;
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};
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|
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/**
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* struct linereq - contains the state of a userspace line request
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* @gdev: the GPIO device the line request pertains to
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* @label: consumer label used to tag GPIO descriptors
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* @num_lines: the number of lines in the lines array
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* @wait: wait queue that handles blocking reads of events
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* @event_buffer_size: the number of elements allocated in @events
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* @events: KFIFO for the GPIO events
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* @seqno: the sequence number for edge events generated on all lines in
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* this line request. Note that this is not used when @num_lines is 1, as
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* the line_seqno is then the same and is cheaper to calculate.
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* @config_mutex: mutex for serializing ioctl() calls to ensure consistency
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* of configuration, particularly multi-step accesses to desc flags.
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* @lines: the lines held by this line request, with @num_lines elements.
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*/
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struct linereq {
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struct gpio_device *gdev;
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const char *label;
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u32 num_lines;
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|
wait_queue_head_t wait;
|
|
u32 event_buffer_size;
|
|
DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);
|
|
atomic_t seqno;
|
|
struct mutex config_mutex;
|
|
struct line lines[];
|
|
};
|
|
|
|
#define GPIO_V2_LINE_BIAS_FLAGS \
|
|
(GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \
|
|
GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \
|
|
GPIO_V2_LINE_FLAG_BIAS_DISABLED)
|
|
|
|
#define GPIO_V2_LINE_DIRECTION_FLAGS \
|
|
(GPIO_V2_LINE_FLAG_INPUT | \
|
|
GPIO_V2_LINE_FLAG_OUTPUT)
|
|
|
|
#define GPIO_V2_LINE_DRIVE_FLAGS \
|
|
(GPIO_V2_LINE_FLAG_OPEN_DRAIN | \
|
|
GPIO_V2_LINE_FLAG_OPEN_SOURCE)
|
|
|
|
#define GPIO_V2_LINE_EDGE_FLAGS \
|
|
(GPIO_V2_LINE_FLAG_EDGE_RISING | \
|
|
GPIO_V2_LINE_FLAG_EDGE_FALLING)
|
|
|
|
#define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS
|
|
|
|
#define GPIO_V2_LINE_VALID_FLAGS \
|
|
(GPIO_V2_LINE_FLAG_ACTIVE_LOW | \
|
|
GPIO_V2_LINE_DIRECTION_FLAGS | \
|
|
GPIO_V2_LINE_DRIVE_FLAGS | \
|
|
GPIO_V2_LINE_EDGE_FLAGS | \
|
|
GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \
|
|
GPIO_V2_LINE_BIAS_FLAGS)
|
|
|
|
static void linereq_put_event(struct linereq *lr,
|
|
struct gpio_v2_line_event *le)
|
|
{
|
|
bool overflow = false;
|
|
|
|
spin_lock(&lr->wait.lock);
|
|
if (kfifo_is_full(&lr->events)) {
|
|
overflow = true;
|
|
kfifo_skip(&lr->events);
|
|
}
|
|
kfifo_in(&lr->events, le, 1);
|
|
spin_unlock(&lr->wait.lock);
|
|
if (!overflow)
|
|
wake_up_poll(&lr->wait, EPOLLIN);
|
|
else
|
|
pr_debug_ratelimited("event FIFO is full - event dropped\n");
|
|
}
|
|
|
|
static u64 line_event_timestamp(struct line *line)
|
|
{
|
|
if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))
|
|
return ktime_get_real_ns();
|
|
|
|
return ktime_get_ns();
|
|
}
|
|
|
|
static irqreturn_t edge_irq_thread(int irq, void *p)
|
|
{
|
|
struct line *line = p;
|
|
struct linereq *lr = line->req;
|
|
struct gpio_v2_line_event le;
|
|
u64 eflags;
|
|
|
|
/* Do not leak kernel stack to userspace */
|
|
memset(&le, 0, sizeof(le));
|
|
|
|
if (line->timestamp_ns) {
|
|
le.timestamp_ns = line->timestamp_ns;
|
|
} else {
|
|
/*
|
|
* We may be running from a nested threaded interrupt in
|
|
* which case we didn't get the timestamp from
|
|
* edge_irq_handler().
|
|
*/
|
|
le.timestamp_ns = line_event_timestamp(line);
|
|
if (lr->num_lines != 1)
|
|
line->req_seqno = atomic_inc_return(&lr->seqno);
|
|
}
|
|
line->timestamp_ns = 0;
|
|
|
|
eflags = READ_ONCE(line->eflags);
|
|
if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) {
|
|
int level = gpiod_get_value_cansleep(line->desc);
|
|
|
|
if (level)
|
|
/* Emit low-to-high event */
|
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
|
|
else
|
|
/* Emit high-to-low event */
|
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
|
|
} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
|
|
/* Emit low-to-high event */
|
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
|
|
} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
|
|
/* Emit high-to-low event */
|
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
|
|
} else {
|
|
return IRQ_NONE;
|
|
}
|
|
line->line_seqno++;
|
|
le.line_seqno = line->line_seqno;
|
|
le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;
|
|
le.offset = gpio_chip_hwgpio(line->desc);
|
|
|
|
linereq_put_event(lr, &le);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static irqreturn_t edge_irq_handler(int irq, void *p)
|
|
{
|
|
struct line *line = p;
|
|
struct linereq *lr = line->req;
|
|
|
|
/*
|
|
* Just store the timestamp in hardirq context so we get it as
|
|
* close in time as possible to the actual event.
|
|
*/
|
|
line->timestamp_ns = line_event_timestamp(line);
|
|
|
|
if (lr->num_lines != 1)
|
|
line->req_seqno = atomic_inc_return(&lr->seqno);
|
|
|
|
return IRQ_WAKE_THREAD;
|
|
}
|
|
|
|
/*
|
|
* returns the current debounced logical value.
|
|
*/
|
|
static bool debounced_value(struct line *line)
|
|
{
|
|
bool value;
|
|
|
|
/*
|
|
* minor race - debouncer may be stopped here, so edge_detector_stop()
|
|
* must leave the value unchanged so the following will read the level
|
|
* from when the debouncer was last running.
|
|
*/
|
|
value = READ_ONCE(line->level);
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
|
|
static irqreturn_t debounce_irq_handler(int irq, void *p)
|
|
{
|
|
struct line *line = p;
|
|
|
|
mod_delayed_work(system_wq, &line->work,
|
|
usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void debounce_work_func(struct work_struct *work)
|
|
{
|
|
struct gpio_v2_line_event le;
|
|
struct line *line = container_of(work, struct line, work.work);
|
|
struct linereq *lr;
|
|
int level;
|
|
u64 eflags;
|
|
|
|
level = gpiod_get_raw_value_cansleep(line->desc);
|
|
if (level < 0) {
|
|
pr_debug_ratelimited("debouncer failed to read line value\n");
|
|
return;
|
|
}
|
|
|
|
if (READ_ONCE(line->level) == level)
|
|
return;
|
|
|
|
WRITE_ONCE(line->level, level);
|
|
|
|
/* -- edge detection -- */
|
|
eflags = READ_ONCE(line->eflags);
|
|
if (!eflags)
|
|
return;
|
|
|
|
/* switch from physical level to logical - if they differ */
|
|
if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))
|
|
level = !level;
|
|
|
|
/* ignore edges that are not being monitored */
|
|
if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
|
|
((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
|
|
return;
|
|
|
|
/* Do not leak kernel stack to userspace */
|
|
memset(&le, 0, sizeof(le));
|
|
|
|
lr = line->req;
|
|
le.timestamp_ns = line_event_timestamp(line);
|
|
le.offset = gpio_chip_hwgpio(line->desc);
|
|
line->line_seqno++;
|
|
le.line_seqno = line->line_seqno;
|
|
le.seqno = (lr->num_lines == 1) ?
|
|
le.line_seqno : atomic_inc_return(&lr->seqno);
|
|
|
|
if (level)
|
|
/* Emit low-to-high event */
|
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
|
|
else
|
|
/* Emit high-to-low event */
|
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
|
|
|
|
linereq_put_event(lr, &le);
|
|
}
|
|
|
|
static int debounce_setup(struct line *line,
|
|
unsigned int debounce_period_us)
|
|
{
|
|
unsigned long irqflags;
|
|
int ret, level, irq;
|
|
|
|
/* try hardware */
|
|
ret = gpiod_set_debounce(line->desc, debounce_period_us);
|
|
if (!ret) {
|
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
|
|
return ret;
|
|
}
|
|
if (ret != -ENOTSUPP)
|
|
return ret;
|
|
|
|
if (debounce_period_us) {
|
|
/* setup software debounce */
|
|
level = gpiod_get_raw_value_cansleep(line->desc);
|
|
if (level < 0)
|
|
return level;
|
|
|
|
irq = gpiod_to_irq(line->desc);
|
|
if (irq < 0)
|
|
return -ENXIO;
|
|
|
|
WRITE_ONCE(line->level, level);
|
|
irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING;
|
|
ret = request_irq(irq, debounce_irq_handler, irqflags,
|
|
line->req->label, line);
|
|
if (ret)
|
|
return ret;
|
|
|
|
WRITE_ONCE(line->sw_debounced, 1);
|
|
line->irq = irq;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx)
|
|
{
|
|
unsigned int i;
|
|
u64 mask = BIT_ULL(line_idx);
|
|
|
|
for (i = 0; i < lc->num_attrs; i++) {
|
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) &&
|
|
(lc->attrs[i].mask & mask))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx)
|
|
{
|
|
unsigned int i;
|
|
u64 mask = BIT_ULL(line_idx);
|
|
|
|
for (i = 0; i < lc->num_attrs; i++) {
|
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) &&
|
|
(lc->attrs[i].mask & mask))
|
|
return lc->attrs[i].attr.debounce_period_us;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void edge_detector_stop(struct line *line)
|
|
{
|
|
if (line->irq) {
|
|
free_irq(line->irq, line);
|
|
line->irq = 0;
|
|
}
|
|
|
|
cancel_delayed_work_sync(&line->work);
|
|
WRITE_ONCE(line->sw_debounced, 0);
|
|
WRITE_ONCE(line->eflags, 0);
|
|
if (line->desc)
|
|
WRITE_ONCE(line->desc->debounce_period_us, 0);
|
|
/* do not change line->level - see comment in debounced_value() */
|
|
}
|
|
|
|
static int edge_detector_setup(struct line *line,
|
|
struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx,
|
|
u64 eflags)
|
|
{
|
|
u32 debounce_period_us;
|
|
unsigned long irqflags = 0;
|
|
int irq, ret;
|
|
|
|
if (eflags && !kfifo_initialized(&line->req->events)) {
|
|
ret = kfifo_alloc(&line->req->events,
|
|
line->req->event_buffer_size, GFP_KERNEL);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
WRITE_ONCE(line->eflags, eflags);
|
|
if (gpio_v2_line_config_debounced(lc, line_idx)) {
|
|
debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx);
|
|
ret = debounce_setup(line, debounce_period_us);
|
|
if (ret)
|
|
return ret;
|
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
|
|
}
|
|
|
|
/* detection disabled or sw debouncer will provide edge detection */
|
|
if (!eflags || READ_ONCE(line->sw_debounced))
|
|
return 0;
|
|
|
|
irq = gpiod_to_irq(line->desc);
|
|
if (irq < 0)
|
|
return -ENXIO;
|
|
|
|
if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?
|
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
|
|
if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?
|
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
|
|
irqflags |= IRQF_ONESHOT;
|
|
|
|
/* Request a thread to read the events */
|
|
ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread,
|
|
irqflags, line->req->label, line);
|
|
if (ret)
|
|
return ret;
|
|
|
|
line->irq = irq;
|
|
return 0;
|
|
}
|
|
|
|
static int edge_detector_update(struct line *line,
|
|
struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx,
|
|
u64 eflags, bool polarity_change)
|
|
{
|
|
unsigned int debounce_period_us =
|
|
gpio_v2_line_config_debounce_period(lc, line_idx);
|
|
|
|
if ((READ_ONCE(line->eflags) == eflags) && !polarity_change &&
|
|
(READ_ONCE(line->desc->debounce_period_us) == debounce_period_us))
|
|
return 0;
|
|
|
|
/* sw debounced and still will be...*/
|
|
if (debounce_period_us && READ_ONCE(line->sw_debounced)) {
|
|
WRITE_ONCE(line->eflags, eflags);
|
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
|
|
return 0;
|
|
}
|
|
|
|
/* reconfiguring edge detection or sw debounce being disabled */
|
|
if ((line->irq && !READ_ONCE(line->sw_debounced)) ||
|
|
(!debounce_period_us && READ_ONCE(line->sw_debounced)))
|
|
edge_detector_stop(line);
|
|
|
|
return edge_detector_setup(line, lc, line_idx, eflags);
|
|
}
|
|
|
|
static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx)
|
|
{
|
|
unsigned int i;
|
|
u64 mask = BIT_ULL(line_idx);
|
|
|
|
for (i = 0; i < lc->num_attrs; i++) {
|
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) &&
|
|
(lc->attrs[i].mask & mask))
|
|
return lc->attrs[i].attr.flags;
|
|
}
|
|
return lc->flags;
|
|
}
|
|
|
|
static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc,
|
|
unsigned int line_idx)
|
|
{
|
|
unsigned int i;
|
|
u64 mask = BIT_ULL(line_idx);
|
|
|
|
for (i = 0; i < lc->num_attrs; i++) {
|
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) &&
|
|
(lc->attrs[i].mask & mask))
|
|
return !!(lc->attrs[i].attr.values & mask);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_v2_line_flags_validate(u64 flags)
|
|
{
|
|
/* Return an error if an unknown flag is set */
|
|
if (flags & ~GPIO_V2_LINE_VALID_FLAGS)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Do not allow both INPUT and OUTPUT flags to be set as they are
|
|
* contradictory.
|
|
*/
|
|
if ((flags & GPIO_V2_LINE_FLAG_INPUT) &&
|
|
(flags & GPIO_V2_LINE_FLAG_OUTPUT))
|
|
return -EINVAL;
|
|
|
|
/* Edge detection requires explicit input. */
|
|
if ((flags & GPIO_V2_LINE_EDGE_FLAGS) &&
|
|
!(flags & GPIO_V2_LINE_FLAG_INPUT))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single
|
|
* request. If the hardware actually supports enabling both at the
|
|
* same time the electrical result would be disastrous.
|
|
*/
|
|
if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) &&
|
|
(flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE))
|
|
return -EINVAL;
|
|
|
|
/* Drive requires explicit output direction. */
|
|
if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) &&
|
|
!(flags & GPIO_V2_LINE_FLAG_OUTPUT))
|
|
return -EINVAL;
|
|
|
|
/* Bias requires explicit direction. */
|
|
if ((flags & GPIO_V2_LINE_BIAS_FLAGS) &&
|
|
!(flags & GPIO_V2_LINE_DIRECTION_FLAGS))
|
|
return -EINVAL;
|
|
|
|
/* Only one bias flag can be set. */
|
|
if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) &&
|
|
(flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN |
|
|
GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) ||
|
|
((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) &&
|
|
(flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP)))
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc,
|
|
unsigned int num_lines)
|
|
{
|
|
unsigned int i;
|
|
u64 flags;
|
|
int ret;
|
|
|
|
if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX)
|
|
return -EINVAL;
|
|
|
|
if (memchr_inv(lc->padding, 0, sizeof(lc->padding)))
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < num_lines; i++) {
|
|
flags = gpio_v2_line_config_flags(lc, i);
|
|
ret = gpio_v2_line_flags_validate(flags);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* debounce requires explicit input */
|
|
if (gpio_v2_line_config_debounced(lc, i) &&
|
|
!(flags & GPIO_V2_LINE_FLAG_INPUT))
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,
|
|
unsigned long *flagsp)
|
|
{
|
|
assign_bit(FLAG_ACTIVE_LOW, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW);
|
|
|
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT)
|
|
set_bit(FLAG_IS_OUT, flagsp);
|
|
else if (flags & GPIO_V2_LINE_FLAG_INPUT)
|
|
clear_bit(FLAG_IS_OUT, flagsp);
|
|
|
|
assign_bit(FLAG_EDGE_RISING, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_EDGE_RISING);
|
|
assign_bit(FLAG_EDGE_FALLING, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_EDGE_FALLING);
|
|
|
|
assign_bit(FLAG_OPEN_DRAIN, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN);
|
|
assign_bit(FLAG_OPEN_SOURCE, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE);
|
|
|
|
assign_bit(FLAG_PULL_UP, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP);
|
|
assign_bit(FLAG_PULL_DOWN, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);
|
|
assign_bit(FLAG_BIAS_DISABLE, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);
|
|
|
|
assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp,
|
|
flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME);
|
|
}
|
|
|
|
static long linereq_get_values(struct linereq *lr, void __user *ip)
|
|
{
|
|
struct gpio_v2_line_values lv;
|
|
DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
|
|
struct gpio_desc **descs;
|
|
unsigned int i, didx, num_get;
|
|
bool val;
|
|
int ret;
|
|
|
|
/* NOTE: It's ok to read values of output lines. */
|
|
if (copy_from_user(&lv, ip, sizeof(lv)))
|
|
return -EFAULT;
|
|
|
|
for (num_get = 0, i = 0; i < lr->num_lines; i++) {
|
|
if (lv.mask & BIT_ULL(i)) {
|
|
num_get++;
|
|
descs = &lr->lines[i].desc;
|
|
}
|
|
}
|
|
|
|
if (num_get == 0)
|
|
return -EINVAL;
|
|
|
|
if (num_get != 1) {
|
|
descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL);
|
|
if (!descs)
|
|
return -ENOMEM;
|
|
for (didx = 0, i = 0; i < lr->num_lines; i++) {
|
|
if (lv.mask & BIT_ULL(i)) {
|
|
descs[didx] = lr->lines[i].desc;
|
|
didx++;
|
|
}
|
|
}
|
|
}
|
|
ret = gpiod_get_array_value_complex(false, true, num_get,
|
|
descs, NULL, vals);
|
|
|
|
if (num_get != 1)
|
|
kfree(descs);
|
|
if (ret)
|
|
return ret;
|
|
|
|
lv.bits = 0;
|
|
for (didx = 0, i = 0; i < lr->num_lines; i++) {
|
|
if (lv.mask & BIT_ULL(i)) {
|
|
if (lr->lines[i].sw_debounced)
|
|
val = debounced_value(&lr->lines[i]);
|
|
else
|
|
val = test_bit(didx, vals);
|
|
if (val)
|
|
lv.bits |= BIT_ULL(i);
|
|
didx++;
|
|
}
|
|
}
|
|
|
|
if (copy_to_user(ip, &lv, sizeof(lv)))
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long linereq_set_values_unlocked(struct linereq *lr,
|
|
struct gpio_v2_line_values *lv)
|
|
{
|
|
DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
|
|
struct gpio_desc **descs;
|
|
unsigned int i, didx, num_set;
|
|
int ret;
|
|
|
|
bitmap_zero(vals, GPIO_V2_LINES_MAX);
|
|
for (num_set = 0, i = 0; i < lr->num_lines; i++) {
|
|
if (lv->mask & BIT_ULL(i)) {
|
|
if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags))
|
|
return -EPERM;
|
|
if (lv->bits & BIT_ULL(i))
|
|
__set_bit(num_set, vals);
|
|
num_set++;
|
|
descs = &lr->lines[i].desc;
|
|
}
|
|
}
|
|
if (num_set == 0)
|
|
return -EINVAL;
|
|
|
|
if (num_set != 1) {
|
|
/* build compacted desc array and values */
|
|
descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL);
|
|
if (!descs)
|
|
return -ENOMEM;
|
|
for (didx = 0, i = 0; i < lr->num_lines; i++) {
|
|
if (lv->mask & BIT_ULL(i)) {
|
|
descs[didx] = lr->lines[i].desc;
|
|
didx++;
|
|
}
|
|
}
|
|
}
|
|
ret = gpiod_set_array_value_complex(false, true, num_set,
|
|
descs, NULL, vals);
|
|
|
|
if (num_set != 1)
|
|
kfree(descs);
|
|
return ret;
|
|
}
|
|
|
|
static long linereq_set_values(struct linereq *lr, void __user *ip)
|
|
{
|
|
struct gpio_v2_line_values lv;
|
|
int ret;
|
|
|
|
if (copy_from_user(&lv, ip, sizeof(lv)))
|
|
return -EFAULT;
|
|
|
|
mutex_lock(&lr->config_mutex);
|
|
|
|
ret = linereq_set_values_unlocked(lr, &lv);
|
|
|
|
mutex_unlock(&lr->config_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static long linereq_set_config_unlocked(struct linereq *lr,
|
|
struct gpio_v2_line_config *lc)
|
|
{
|
|
struct gpio_desc *desc;
|
|
unsigned int i;
|
|
u64 flags;
|
|
bool polarity_change;
|
|
int ret;
|
|
|
|
for (i = 0; i < lr->num_lines; i++) {
|
|
desc = lr->lines[i].desc;
|
|
flags = gpio_v2_line_config_flags(lc, i);
|
|
polarity_change =
|
|
(!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) !=
|
|
((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0));
|
|
|
|
gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
|
|
/*
|
|
* Lines have to be requested explicitly for input
|
|
* or output, else the line will be treated "as is".
|
|
*/
|
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
|
|
int val = gpio_v2_line_config_output_value(lc, i);
|
|
|
|
edge_detector_stop(&lr->lines[i]);
|
|
ret = gpiod_direction_output(desc, val);
|
|
if (ret)
|
|
return ret;
|
|
} else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
|
|
ret = gpiod_direction_input(desc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = edge_detector_update(&lr->lines[i], lc, i,
|
|
flags & GPIO_V2_LINE_EDGE_FLAGS,
|
|
polarity_change);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier,
|
|
GPIO_V2_LINE_CHANGED_CONFIG,
|
|
desc);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static long linereq_set_config(struct linereq *lr, void __user *ip)
|
|
{
|
|
struct gpio_v2_line_config lc;
|
|
int ret;
|
|
|
|
if (copy_from_user(&lc, ip, sizeof(lc)))
|
|
return -EFAULT;
|
|
|
|
ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&lr->config_mutex);
|
|
|
|
ret = linereq_set_config_unlocked(lr, &lc);
|
|
|
|
mutex_unlock(&lr->config_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static long linereq_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct linereq *lr = file->private_data;
|
|
void __user *ip = (void __user *)arg;
|
|
|
|
if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL)
|
|
return linereq_get_values(lr, ip);
|
|
else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL)
|
|
return linereq_set_values(lr, ip);
|
|
else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL)
|
|
return linereq_set_config(lr, ip);
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long linereq_ioctl_compat(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static __poll_t linereq_poll(struct file *file,
|
|
struct poll_table_struct *wait)
|
|
{
|
|
struct linereq *lr = file->private_data;
|
|
__poll_t events = 0;
|
|
|
|
poll_wait(file, &lr->wait, wait);
|
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events,
|
|
&lr->wait.lock))
|
|
events = EPOLLIN | EPOLLRDNORM;
|
|
|
|
return events;
|
|
}
|
|
|
|
static ssize_t linereq_read(struct file *file,
|
|
char __user *buf,
|
|
size_t count,
|
|
loff_t *f_ps)
|
|
{
|
|
struct linereq *lr = file->private_data;
|
|
struct gpio_v2_line_event le;
|
|
ssize_t bytes_read = 0;
|
|
int ret;
|
|
|
|
if (count < sizeof(le))
|
|
return -EINVAL;
|
|
|
|
do {
|
|
spin_lock(&lr->wait.lock);
|
|
if (kfifo_is_empty(&lr->events)) {
|
|
if (bytes_read) {
|
|
spin_unlock(&lr->wait.lock);
|
|
return bytes_read;
|
|
}
|
|
|
|
if (file->f_flags & O_NONBLOCK) {
|
|
spin_unlock(&lr->wait.lock);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
ret = wait_event_interruptible_locked(lr->wait,
|
|
!kfifo_is_empty(&lr->events));
|
|
if (ret) {
|
|
spin_unlock(&lr->wait.lock);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = kfifo_out(&lr->events, &le, 1);
|
|
spin_unlock(&lr->wait.lock);
|
|
if (ret != 1) {
|
|
/*
|
|
* This should never happen - we were holding the
|
|
* lock from the moment we learned the fifo is no
|
|
* longer empty until now.
|
|
*/
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
|
|
if (copy_to_user(buf + bytes_read, &le, sizeof(le)))
|
|
return -EFAULT;
|
|
bytes_read += sizeof(le);
|
|
} while (count >= bytes_read + sizeof(le));
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
static void linereq_free(struct linereq *lr)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < lr->num_lines; i++) {
|
|
edge_detector_stop(&lr->lines[i]);
|
|
if (lr->lines[i].desc)
|
|
gpiod_free(lr->lines[i].desc);
|
|
}
|
|
kfifo_free(&lr->events);
|
|
kfree(lr->label);
|
|
put_device(&lr->gdev->dev);
|
|
kfree(lr);
|
|
}
|
|
|
|
static int linereq_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct linereq *lr = file->private_data;
|
|
|
|
linereq_free(lr);
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations line_fileops = {
|
|
.release = linereq_release,
|
|
.read = linereq_read,
|
|
.poll = linereq_poll,
|
|
.owner = THIS_MODULE,
|
|
.llseek = noop_llseek,
|
|
.unlocked_ioctl = linereq_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = linereq_ioctl_compat,
|
|
#endif
|
|
};
|
|
|
|
static int linereq_create(struct gpio_device *gdev, void __user *ip)
|
|
{
|
|
struct gpio_v2_line_request ulr;
|
|
struct gpio_v2_line_config *lc;
|
|
struct linereq *lr;
|
|
struct file *file;
|
|
u64 flags;
|
|
unsigned int i;
|
|
int fd, ret;
|
|
|
|
if (copy_from_user(&ulr, ip, sizeof(ulr)))
|
|
return -EFAULT;
|
|
|
|
if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX))
|
|
return -EINVAL;
|
|
|
|
if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding)))
|
|
return -EINVAL;
|
|
|
|
lc = &ulr.config;
|
|
ret = gpio_v2_line_config_validate(lc, ulr.num_lines);
|
|
if (ret)
|
|
return ret;
|
|
|
|
lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
|
|
if (!lr)
|
|
return -ENOMEM;
|
|
|
|
lr->gdev = gdev;
|
|
get_device(&gdev->dev);
|
|
|
|
for (i = 0; i < ulr.num_lines; i++) {
|
|
lr->lines[i].req = lr;
|
|
WRITE_ONCE(lr->lines[i].sw_debounced, 0);
|
|
INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func);
|
|
}
|
|
|
|
if (ulr.consumer[0] != '\0') {
|
|
/* label is only initialized if consumer is set */
|
|
lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1,
|
|
GFP_KERNEL);
|
|
if (!lr->label) {
|
|
ret = -ENOMEM;
|
|
goto out_free_linereq;
|
|
}
|
|
}
|
|
|
|
mutex_init(&lr->config_mutex);
|
|
init_waitqueue_head(&lr->wait);
|
|
lr->event_buffer_size = ulr.event_buffer_size;
|
|
if (lr->event_buffer_size == 0)
|
|
lr->event_buffer_size = ulr.num_lines * 16;
|
|
else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16)
|
|
lr->event_buffer_size = GPIO_V2_LINES_MAX * 16;
|
|
|
|
atomic_set(&lr->seqno, 0);
|
|
lr->num_lines = ulr.num_lines;
|
|
|
|
/* Request each GPIO */
|
|
for (i = 0; i < ulr.num_lines; i++) {
|
|
u32 offset = ulr.offsets[i];
|
|
struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset);
|
|
|
|
if (IS_ERR(desc)) {
|
|
ret = PTR_ERR(desc);
|
|
goto out_free_linereq;
|
|
}
|
|
|
|
ret = gpiod_request(desc, lr->label);
|
|
if (ret)
|
|
goto out_free_linereq;
|
|
|
|
lr->lines[i].desc = desc;
|
|
flags = gpio_v2_line_config_flags(lc, i);
|
|
gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
|
|
|
|
ret = gpiod_set_transitory(desc, false);
|
|
if (ret < 0)
|
|
goto out_free_linereq;
|
|
|
|
/*
|
|
* Lines have to be requested explicitly for input
|
|
* or output, else the line will be treated "as is".
|
|
*/
|
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
|
|
int val = gpio_v2_line_config_output_value(lc, i);
|
|
|
|
ret = gpiod_direction_output(desc, val);
|
|
if (ret)
|
|
goto out_free_linereq;
|
|
} else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
|
|
ret = gpiod_direction_input(desc);
|
|
if (ret)
|
|
goto out_free_linereq;
|
|
|
|
ret = edge_detector_setup(&lr->lines[i], lc, i,
|
|
flags & GPIO_V2_LINE_EDGE_FLAGS);
|
|
if (ret)
|
|
goto out_free_linereq;
|
|
}
|
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier,
|
|
GPIO_V2_LINE_CHANGED_REQUESTED, desc);
|
|
|
|
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
|
|
offset);
|
|
}
|
|
|
|
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
ret = fd;
|
|
goto out_free_linereq;
|
|
}
|
|
|
|
file = anon_inode_getfile("gpio-line", &line_fileops, lr,
|
|
O_RDONLY | O_CLOEXEC);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
goto out_put_unused_fd;
|
|
}
|
|
|
|
ulr.fd = fd;
|
|
if (copy_to_user(ip, &ulr, sizeof(ulr))) {
|
|
/*
|
|
* fput() will trigger the release() callback, so do not go onto
|
|
* the regular error cleanup path here.
|
|
*/
|
|
fput(file);
|
|
put_unused_fd(fd);
|
|
return -EFAULT;
|
|
}
|
|
|
|
fd_install(fd, file);
|
|
|
|
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
|
|
lr->num_lines);
|
|
|
|
return 0;
|
|
|
|
out_put_unused_fd:
|
|
put_unused_fd(fd);
|
|
out_free_linereq:
|
|
linereq_free(lr);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
|
|
/*
|
|
* GPIO line event management
|
|
*/
|
|
|
|
/**
|
|
* struct lineevent_state - contains the state of a userspace event
|
|
* @gdev: the GPIO device the event pertains to
|
|
* @label: consumer label used to tag descriptors
|
|
* @desc: the GPIO descriptor held by this event
|
|
* @eflags: the event flags this line was requested with
|
|
* @irq: the interrupt that trigger in response to events on this GPIO
|
|
* @wait: wait queue that handles blocking reads of events
|
|
* @events: KFIFO for the GPIO events
|
|
* @timestamp: cache for the timestamp storing it between hardirq
|
|
* and IRQ thread, used to bring the timestamp close to the actual
|
|
* event
|
|
*/
|
|
struct lineevent_state {
|
|
struct gpio_device *gdev;
|
|
const char *label;
|
|
struct gpio_desc *desc;
|
|
u32 eflags;
|
|
int irq;
|
|
wait_queue_head_t wait;
|
|
DECLARE_KFIFO(events, struct gpioevent_data, 16);
|
|
u64 timestamp;
|
|
};
|
|
|
|
#define GPIOEVENT_REQUEST_VALID_FLAGS \
|
|
(GPIOEVENT_REQUEST_RISING_EDGE | \
|
|
GPIOEVENT_REQUEST_FALLING_EDGE)
|
|
|
|
static __poll_t lineevent_poll(struct file *file,
|
|
struct poll_table_struct *wait)
|
|
{
|
|
struct lineevent_state *le = file->private_data;
|
|
__poll_t events = 0;
|
|
|
|
poll_wait(file, &le->wait, wait);
|
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock))
|
|
events = EPOLLIN | EPOLLRDNORM;
|
|
|
|
return events;
|
|
}
|
|
|
|
struct compat_gpioeevent_data {
|
|
compat_u64 timestamp;
|
|
u32 id;
|
|
};
|
|
|
|
static ssize_t lineevent_read(struct file *file,
|
|
char __user *buf,
|
|
size_t count,
|
|
loff_t *f_ps)
|
|
{
|
|
struct lineevent_state *le = file->private_data;
|
|
struct gpioevent_data ge;
|
|
ssize_t bytes_read = 0;
|
|
ssize_t ge_size;
|
|
int ret;
|
|
|
|
/*
|
|
* When compatible system call is being used the struct gpioevent_data,
|
|
* in case of at least ia32, has different size due to the alignment
|
|
* differences. Because we have first member 64 bits followed by one of
|
|
* 32 bits there is no gap between them. The only difference is the
|
|
* padding at the end of the data structure. Hence, we calculate the
|
|
* actual sizeof() and pass this as an argument to copy_to_user() to
|
|
* drop unneeded bytes from the output.
|
|
*/
|
|
if (compat_need_64bit_alignment_fixup())
|
|
ge_size = sizeof(struct compat_gpioeevent_data);
|
|
else
|
|
ge_size = sizeof(struct gpioevent_data);
|
|
if (count < ge_size)
|
|
return -EINVAL;
|
|
|
|
do {
|
|
spin_lock(&le->wait.lock);
|
|
if (kfifo_is_empty(&le->events)) {
|
|
if (bytes_read) {
|
|
spin_unlock(&le->wait.lock);
|
|
return bytes_read;
|
|
}
|
|
|
|
if (file->f_flags & O_NONBLOCK) {
|
|
spin_unlock(&le->wait.lock);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
ret = wait_event_interruptible_locked(le->wait,
|
|
!kfifo_is_empty(&le->events));
|
|
if (ret) {
|
|
spin_unlock(&le->wait.lock);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = kfifo_out(&le->events, &ge, 1);
|
|
spin_unlock(&le->wait.lock);
|
|
if (ret != 1) {
|
|
/*
|
|
* This should never happen - we were holding the lock
|
|
* from the moment we learned the fifo is no longer
|
|
* empty until now.
|
|
*/
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
|
|
if (copy_to_user(buf + bytes_read, &ge, ge_size))
|
|
return -EFAULT;
|
|
bytes_read += ge_size;
|
|
} while (count >= bytes_read + ge_size);
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
static void lineevent_free(struct lineevent_state *le)
|
|
{
|
|
if (le->irq)
|
|
free_irq(le->irq, le);
|
|
if (le->desc)
|
|
gpiod_free(le->desc);
|
|
kfree(le->label);
|
|
put_device(&le->gdev->dev);
|
|
kfree(le);
|
|
}
|
|
|
|
static int lineevent_release(struct inode *inode, struct file *file)
|
|
{
|
|
lineevent_free(file->private_data);
|
|
return 0;
|
|
}
|
|
|
|
static long lineevent_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct lineevent_state *le = file->private_data;
|
|
void __user *ip = (void __user *)arg;
|
|
struct gpiohandle_data ghd;
|
|
|
|
/*
|
|
* We can get the value for an event line but not set it,
|
|
* because it is input by definition.
|
|
*/
|
|
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
|
|
int val;
|
|
|
|
memset(&ghd, 0, sizeof(ghd));
|
|
|
|
val = gpiod_get_value_cansleep(le->desc);
|
|
if (val < 0)
|
|
return val;
|
|
ghd.values[0] = val;
|
|
|
|
if (copy_to_user(ip, &ghd, sizeof(ghd)))
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long lineevent_ioctl_compat(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return lineevent_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static const struct file_operations lineevent_fileops = {
|
|
.release = lineevent_release,
|
|
.read = lineevent_read,
|
|
.poll = lineevent_poll,
|
|
.owner = THIS_MODULE,
|
|
.llseek = noop_llseek,
|
|
.unlocked_ioctl = lineevent_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = lineevent_ioctl_compat,
|
|
#endif
|
|
};
|
|
|
|
static irqreturn_t lineevent_irq_thread(int irq, void *p)
|
|
{
|
|
struct lineevent_state *le = p;
|
|
struct gpioevent_data ge;
|
|
int ret;
|
|
|
|
/* Do not leak kernel stack to userspace */
|
|
memset(&ge, 0, sizeof(ge));
|
|
|
|
/*
|
|
* We may be running from a nested threaded interrupt in which case
|
|
* we didn't get the timestamp from lineevent_irq_handler().
|
|
*/
|
|
if (!le->timestamp)
|
|
ge.timestamp = ktime_get_ns();
|
|
else
|
|
ge.timestamp = le->timestamp;
|
|
|
|
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
|
|
&& le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
|
|
int level = gpiod_get_value_cansleep(le->desc);
|
|
|
|
if (level)
|
|
/* Emit low-to-high event */
|
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
|
|
else
|
|
/* Emit high-to-low event */
|
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
|
|
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
|
|
/* Emit low-to-high event */
|
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
|
|
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
|
|
/* Emit high-to-low event */
|
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
|
|
} else {
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge,
|
|
1, &le->wait.lock);
|
|
if (ret)
|
|
wake_up_poll(&le->wait, EPOLLIN);
|
|
else
|
|
pr_debug_ratelimited("event FIFO is full - event dropped\n");
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static irqreturn_t lineevent_irq_handler(int irq, void *p)
|
|
{
|
|
struct lineevent_state *le = p;
|
|
|
|
/*
|
|
* Just store the timestamp in hardirq context so we get it as
|
|
* close in time as possible to the actual event.
|
|
*/
|
|
le->timestamp = ktime_get_ns();
|
|
|
|
return IRQ_WAKE_THREAD;
|
|
}
|
|
|
|
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
|
|
{
|
|
struct gpioevent_request eventreq;
|
|
struct lineevent_state *le;
|
|
struct gpio_desc *desc;
|
|
struct file *file;
|
|
u32 offset;
|
|
u32 lflags;
|
|
u32 eflags;
|
|
int fd;
|
|
int ret;
|
|
int irq, irqflags = 0;
|
|
|
|
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
|
|
return -EFAULT;
|
|
|
|
offset = eventreq.lineoffset;
|
|
lflags = eventreq.handleflags;
|
|
eflags = eventreq.eventflags;
|
|
|
|
desc = gpiochip_get_desc(gdev->chip, offset);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|
|
/* Return an error if a unknown flag is set */
|
|
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
|
|
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS))
|
|
return -EINVAL;
|
|
|
|
/* This is just wrong: we don't look for events on output lines */
|
|
if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
|
|
(lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
|
|
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
|
|
return -EINVAL;
|
|
|
|
/* Only one bias flag can be set. */
|
|
if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
|
|
(lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
|
|
GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
|
|
((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
|
|
(lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
|
|
return -EINVAL;
|
|
|
|
le = kzalloc(sizeof(*le), GFP_KERNEL);
|
|
if (!le)
|
|
return -ENOMEM;
|
|
le->gdev = gdev;
|
|
get_device(&gdev->dev);
|
|
|
|
if (eventreq.consumer_label[0] != '\0') {
|
|
/* label is only initialized if consumer_label is set */
|
|
le->label = kstrndup(eventreq.consumer_label,
|
|
sizeof(eventreq.consumer_label) - 1,
|
|
GFP_KERNEL);
|
|
if (!le->label) {
|
|
ret = -ENOMEM;
|
|
goto out_free_le;
|
|
}
|
|
}
|
|
|
|
ret = gpiod_request(desc, le->label);
|
|
if (ret)
|
|
goto out_free_le;
|
|
le->desc = desc;
|
|
le->eflags = eflags;
|
|
|
|
linehandle_flags_to_desc_flags(lflags, &desc->flags);
|
|
|
|
ret = gpiod_direction_input(desc);
|
|
if (ret)
|
|
goto out_free_le;
|
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier,
|
|
GPIO_V2_LINE_CHANGED_REQUESTED, desc);
|
|
|
|
irq = gpiod_to_irq(desc);
|
|
if (irq <= 0) {
|
|
ret = -ENODEV;
|
|
goto out_free_le;
|
|
}
|
|
le->irq = irq;
|
|
|
|
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
|
|
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
|
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
|
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
|
|
irqflags |= IRQF_ONESHOT;
|
|
|
|
INIT_KFIFO(le->events);
|
|
init_waitqueue_head(&le->wait);
|
|
|
|
/* Request a thread to read the events */
|
|
ret = request_threaded_irq(le->irq,
|
|
lineevent_irq_handler,
|
|
lineevent_irq_thread,
|
|
irqflags,
|
|
le->label,
|
|
le);
|
|
if (ret)
|
|
goto out_free_le;
|
|
|
|
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
|
|
if (fd < 0) {
|
|
ret = fd;
|
|
goto out_free_le;
|
|
}
|
|
|
|
file = anon_inode_getfile("gpio-event",
|
|
&lineevent_fileops,
|
|
le,
|
|
O_RDONLY | O_CLOEXEC);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
goto out_put_unused_fd;
|
|
}
|
|
|
|
eventreq.fd = fd;
|
|
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
|
|
/*
|
|
* fput() will trigger the release() callback, so do not go onto
|
|
* the regular error cleanup path here.
|
|
*/
|
|
fput(file);
|
|
put_unused_fd(fd);
|
|
return -EFAULT;
|
|
}
|
|
|
|
fd_install(fd, file);
|
|
|
|
return 0;
|
|
|
|
out_put_unused_fd:
|
|
put_unused_fd(fd);
|
|
out_free_le:
|
|
lineevent_free(le);
|
|
return ret;
|
|
}
|
|
|
|
static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2,
|
|
struct gpioline_info *info_v1)
|
|
{
|
|
u64 flagsv2 = info_v2->flags;
|
|
|
|
memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name));
|
|
memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer));
|
|
info_v1->line_offset = info_v2->offset;
|
|
info_v1->flags = 0;
|
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_USED)
|
|
info_v1->flags |= GPIOLINE_FLAG_KERNEL;
|
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT)
|
|
info_v1->flags |= GPIOLINE_FLAG_IS_OUT;
|
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW)
|
|
info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
|
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN)
|
|
info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN;
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE)
|
|
info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE;
|
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP)
|
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN)
|
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED)
|
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
|
|
}
|
|
|
|
static void gpio_v2_line_info_changed_to_v1(
|
|
struct gpio_v2_line_info_changed *lic_v2,
|
|
struct gpioline_info_changed *lic_v1)
|
|
{
|
|
memset(lic_v1, 0, sizeof(*lic_v1));
|
|
gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info);
|
|
lic_v1->timestamp = lic_v2->timestamp_ns;
|
|
lic_v1->event_type = lic_v2->event_type;
|
|
}
|
|
|
|
#endif /* CONFIG_GPIO_CDEV_V1 */
|
|
|
|
static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
|
|
struct gpio_v2_line_info *info)
|
|
{
|
|
struct gpio_chip *gc = desc->gdev->chip;
|
|
bool ok_for_pinctrl;
|
|
unsigned long flags;
|
|
u32 debounce_period_us;
|
|
unsigned int num_attrs = 0;
|
|
|
|
memset(info, 0, sizeof(*info));
|
|
info->offset = gpio_chip_hwgpio(desc);
|
|
|
|
/*
|
|
* This function takes a mutex so we must check this before taking
|
|
* the spinlock.
|
|
*
|
|
* FIXME: find a non-racy way to retrieve this information. Maybe a
|
|
* lock common to both frameworks?
|
|
*/
|
|
ok_for_pinctrl =
|
|
pinctrl_gpio_can_use_line(gc->base + info->offset);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (desc->name)
|
|
strscpy(info->name, desc->name, sizeof(info->name));
|
|
|
|
if (desc->label)
|
|
strscpy(info->consumer, desc->label, sizeof(info->consumer));
|
|
|
|
/*
|
|
* Userspace only need to know that the kernel is using this GPIO so
|
|
* it can't use it.
|
|
*/
|
|
info->flags = 0;
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags) ||
|
|
test_bit(FLAG_IS_HOGGED, &desc->flags) ||
|
|
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
|
|
test_bit(FLAG_EXPORT, &desc->flags) ||
|
|
test_bit(FLAG_SYSFS, &desc->flags) ||
|
|
!gpiochip_line_is_valid(gc, info->offset) ||
|
|
!ok_for_pinctrl)
|
|
info->flags |= GPIO_V2_LINE_FLAG_USED;
|
|
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_OUTPUT;
|
|
else
|
|
info->flags |= GPIO_V2_LINE_FLAG_INPUT;
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW;
|
|
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN;
|
|
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE;
|
|
|
|
if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED;
|
|
if (test_bit(FLAG_PULL_DOWN, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN;
|
|
if (test_bit(FLAG_PULL_UP, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP;
|
|
|
|
if (test_bit(FLAG_EDGE_RISING, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING;
|
|
if (test_bit(FLAG_EDGE_FALLING, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING;
|
|
|
|
if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags))
|
|
info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME;
|
|
|
|
debounce_period_us = READ_ONCE(desc->debounce_period_us);
|
|
if (debounce_period_us) {
|
|
info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
|
|
info->attrs[num_attrs].debounce_period_us = debounce_period_us;
|
|
num_attrs++;
|
|
}
|
|
info->num_attrs = num_attrs;
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
}
|
|
|
|
struct gpio_chardev_data {
|
|
struct gpio_device *gdev;
|
|
wait_queue_head_t wait;
|
|
DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32);
|
|
struct notifier_block lineinfo_changed_nb;
|
|
unsigned long *watched_lines;
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
atomic_t watch_abi_version;
|
|
#endif
|
|
};
|
|
|
|
static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip)
|
|
{
|
|
struct gpio_device *gdev = cdev->gdev;
|
|
struct gpiochip_info chipinfo;
|
|
|
|
memset(&chipinfo, 0, sizeof(chipinfo));
|
|
|
|
strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name));
|
|
strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label));
|
|
chipinfo.lines = gdev->ngpio;
|
|
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
/*
|
|
* returns 0 if the versions match, else the previously selected ABI version
|
|
*/
|
|
static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata,
|
|
unsigned int version)
|
|
{
|
|
int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version);
|
|
|
|
if (abiv == version)
|
|
return 0;
|
|
|
|
return abiv;
|
|
}
|
|
|
|
static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip,
|
|
bool watch)
|
|
{
|
|
struct gpio_desc *desc;
|
|
struct gpioline_info lineinfo;
|
|
struct gpio_v2_line_info lineinfo_v2;
|
|
|
|
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
|
|
return -EFAULT;
|
|
|
|
/* this doubles as a range check on line_offset */
|
|
desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|
|
if (watch) {
|
|
if (lineinfo_ensure_abi_version(cdev, 1))
|
|
return -EPERM;
|
|
|
|
if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines))
|
|
return -EBUSY;
|
|
}
|
|
|
|
gpio_desc_to_lineinfo(desc, &lineinfo_v2);
|
|
gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
|
|
|
|
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
|
|
if (watch)
|
|
clear_bit(lineinfo.line_offset, cdev->watched_lines);
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
|
|
bool watch)
|
|
{
|
|
struct gpio_desc *desc;
|
|
struct gpio_v2_line_info lineinfo;
|
|
|
|
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
|
|
return -EFAULT;
|
|
|
|
if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding)))
|
|
return -EINVAL;
|
|
|
|
desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset);
|
|
if (IS_ERR(desc))
|
|
return PTR_ERR(desc);
|
|
|
|
if (watch) {
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
if (lineinfo_ensure_abi_version(cdev, 2))
|
|
return -EPERM;
|
|
#endif
|
|
if (test_and_set_bit(lineinfo.offset, cdev->watched_lines))
|
|
return -EBUSY;
|
|
}
|
|
gpio_desc_to_lineinfo(desc, &lineinfo);
|
|
|
|
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
|
|
if (watch)
|
|
clear_bit(lineinfo.offset, cdev->watched_lines);
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip)
|
|
{
|
|
__u32 offset;
|
|
|
|
if (copy_from_user(&offset, ip, sizeof(offset)))
|
|
return -EFAULT;
|
|
|
|
if (offset >= cdev->gdev->ngpio)
|
|
return -EINVAL;
|
|
|
|
if (!test_and_clear_bit(offset, cdev->watched_lines))
|
|
return -EBUSY;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* gpio_ioctl() - ioctl handler for the GPIO chardev
|
|
*/
|
|
static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct gpio_chardev_data *cdev = file->private_data;
|
|
struct gpio_device *gdev = cdev->gdev;
|
|
void __user *ip = (void __user *)arg;
|
|
|
|
/* We fail any subsequent ioctl():s when the chip is gone */
|
|
if (!gdev->chip)
|
|
return -ENODEV;
|
|
|
|
/* Fill in the struct and pass to userspace */
|
|
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
|
|
return chipinfo_get(cdev, ip);
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
|
|
return linehandle_create(gdev, ip);
|
|
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
|
|
return lineevent_create(gdev, ip);
|
|
} else if (cmd == GPIO_GET_LINEINFO_IOCTL ||
|
|
cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
|
|
return lineinfo_get_v1(cdev, ip,
|
|
cmd == GPIO_GET_LINEINFO_WATCH_IOCTL);
|
|
#endif /* CONFIG_GPIO_CDEV_V1 */
|
|
} else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL ||
|
|
cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) {
|
|
return lineinfo_get(cdev, ip,
|
|
cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL);
|
|
} else if (cmd == GPIO_V2_GET_LINE_IOCTL) {
|
|
return linereq_create(gdev, ip);
|
|
} else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
|
|
return lineinfo_unwatch(cdev, ip);
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long gpio_ioctl_compat(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
return gpio_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
|
|
}
|
|
#endif
|
|
|
|
static struct gpio_chardev_data *
|
|
to_gpio_chardev_data(struct notifier_block *nb)
|
|
{
|
|
return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb);
|
|
}
|
|
|
|
static int lineinfo_changed_notify(struct notifier_block *nb,
|
|
unsigned long action, void *data)
|
|
{
|
|
struct gpio_chardev_data *cdev = to_gpio_chardev_data(nb);
|
|
struct gpio_v2_line_info_changed chg;
|
|
struct gpio_desc *desc = data;
|
|
int ret;
|
|
|
|
if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines))
|
|
return NOTIFY_DONE;
|
|
|
|
memset(&chg, 0, sizeof(chg));
|
|
chg.event_type = action;
|
|
chg.timestamp_ns = ktime_get_ns();
|
|
gpio_desc_to_lineinfo(desc, &chg.info);
|
|
|
|
ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
|
|
if (ret)
|
|
wake_up_poll(&cdev->wait, EPOLLIN);
|
|
else
|
|
pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n");
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static __poll_t lineinfo_watch_poll(struct file *file,
|
|
struct poll_table_struct *pollt)
|
|
{
|
|
struct gpio_chardev_data *cdev = file->private_data;
|
|
__poll_t events = 0;
|
|
|
|
poll_wait(file, &cdev->wait, pollt);
|
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events,
|
|
&cdev->wait.lock))
|
|
events = EPOLLIN | EPOLLRDNORM;
|
|
|
|
return events;
|
|
}
|
|
|
|
static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *off)
|
|
{
|
|
struct gpio_chardev_data *cdev = file->private_data;
|
|
struct gpio_v2_line_info_changed event;
|
|
ssize_t bytes_read = 0;
|
|
int ret;
|
|
size_t event_size;
|
|
|
|
#ifndef CONFIG_GPIO_CDEV_V1
|
|
event_size = sizeof(struct gpio_v2_line_info_changed);
|
|
if (count < event_size)
|
|
return -EINVAL;
|
|
#endif
|
|
|
|
do {
|
|
spin_lock(&cdev->wait.lock);
|
|
if (kfifo_is_empty(&cdev->events)) {
|
|
if (bytes_read) {
|
|
spin_unlock(&cdev->wait.lock);
|
|
return bytes_read;
|
|
}
|
|
|
|
if (file->f_flags & O_NONBLOCK) {
|
|
spin_unlock(&cdev->wait.lock);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
ret = wait_event_interruptible_locked(cdev->wait,
|
|
!kfifo_is_empty(&cdev->events));
|
|
if (ret) {
|
|
spin_unlock(&cdev->wait.lock);
|
|
return ret;
|
|
}
|
|
}
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
/* must be after kfifo check so watch_abi_version is set */
|
|
if (atomic_read(&cdev->watch_abi_version) == 2)
|
|
event_size = sizeof(struct gpio_v2_line_info_changed);
|
|
else
|
|
event_size = sizeof(struct gpioline_info_changed);
|
|
if (count < event_size) {
|
|
spin_unlock(&cdev->wait.lock);
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
ret = kfifo_out(&cdev->events, &event, 1);
|
|
spin_unlock(&cdev->wait.lock);
|
|
if (ret != 1) {
|
|
ret = -EIO;
|
|
break;
|
|
/* We should never get here. See lineevent_read(). */
|
|
}
|
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1
|
|
if (event_size == sizeof(struct gpio_v2_line_info_changed)) {
|
|
if (copy_to_user(buf + bytes_read, &event, event_size))
|
|
return -EFAULT;
|
|
} else {
|
|
struct gpioline_info_changed event_v1;
|
|
|
|
gpio_v2_line_info_changed_to_v1(&event, &event_v1);
|
|
if (copy_to_user(buf + bytes_read, &event_v1,
|
|
event_size))
|
|
return -EFAULT;
|
|
}
|
|
#else
|
|
if (copy_to_user(buf + bytes_read, &event, event_size))
|
|
return -EFAULT;
|
|
#endif
|
|
bytes_read += event_size;
|
|
} while (count >= bytes_read + sizeof(event));
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
/**
|
|
* gpio_chrdev_open() - open the chardev for ioctl operations
|
|
* @inode: inode for this chardev
|
|
* @file: file struct for storing private data
|
|
* Returns 0 on success
|
|
*/
|
|
static int gpio_chrdev_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct gpio_device *gdev = container_of(inode->i_cdev,
|
|
struct gpio_device, chrdev);
|
|
struct gpio_chardev_data *cdev;
|
|
int ret = -ENOMEM;
|
|
|
|
/* Fail on open if the backing gpiochip is gone */
|
|
if (!gdev->chip)
|
|
return -ENODEV;
|
|
|
|
cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
|
|
if (!cdev)
|
|
return -ENOMEM;
|
|
|
|
cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
|
|
if (!cdev->watched_lines)
|
|
goto out_free_cdev;
|
|
|
|
init_waitqueue_head(&cdev->wait);
|
|
INIT_KFIFO(cdev->events);
|
|
cdev->gdev = gdev;
|
|
|
|
cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
|
|
ret = blocking_notifier_chain_register(&gdev->notifier,
|
|
&cdev->lineinfo_changed_nb);
|
|
if (ret)
|
|
goto out_free_bitmap;
|
|
|
|
get_device(&gdev->dev);
|
|
file->private_data = cdev;
|
|
|
|
ret = nonseekable_open(inode, file);
|
|
if (ret)
|
|
goto out_unregister_notifier;
|
|
|
|
return ret;
|
|
|
|
out_unregister_notifier:
|
|
blocking_notifier_chain_unregister(&gdev->notifier,
|
|
&cdev->lineinfo_changed_nb);
|
|
out_free_bitmap:
|
|
bitmap_free(cdev->watched_lines);
|
|
out_free_cdev:
|
|
kfree(cdev);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gpio_chrdev_release() - close chardev after ioctl operations
|
|
* @inode: inode for this chardev
|
|
* @file: file struct for storing private data
|
|
* Returns 0 on success
|
|
*/
|
|
static int gpio_chrdev_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct gpio_chardev_data *cdev = file->private_data;
|
|
struct gpio_device *gdev = cdev->gdev;
|
|
|
|
bitmap_free(cdev->watched_lines);
|
|
blocking_notifier_chain_unregister(&gdev->notifier,
|
|
&cdev->lineinfo_changed_nb);
|
|
put_device(&gdev->dev);
|
|
kfree(cdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations gpio_fileops = {
|
|
.release = gpio_chrdev_release,
|
|
.open = gpio_chrdev_open,
|
|
.poll = lineinfo_watch_poll,
|
|
.read = lineinfo_watch_read,
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.unlocked_ioctl = gpio_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = gpio_ioctl_compat,
|
|
#endif
|
|
};
|
|
|
|
int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt)
|
|
{
|
|
int ret;
|
|
|
|
cdev_init(&gdev->chrdev, &gpio_fileops);
|
|
gdev->chrdev.owner = THIS_MODULE;
|
|
gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id);
|
|
|
|
ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
|
|
MAJOR(devt), gdev->id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void gpiolib_cdev_unregister(struct gpio_device *gdev)
|
|
{
|
|
cdev_device_del(&gdev->chrdev, &gdev->dev);
|
|
}
|