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![Dan Carpenter](/assets/img/avatar_default.png)
copy_from_user() returns the number of bytes remaining to be copied but
we want to return negative error codes on failue.
Fixes: 9202ba2397
("gpio: mockup: implement event injecting over debugfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
438 lines
9.7 KiB
C
438 lines
9.7 KiB
C
/*
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* GPIO Testing Device Driver
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*
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* Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com>
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* Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/gpio/driver.h>
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#include <linux/gpio/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/irq_work.h>
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include "gpiolib.h"
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#define GPIO_MOCKUP_NAME "gpio-mockup"
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#define GPIO_MOCKUP_MAX_GC 10
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enum {
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DIR_IN = 0,
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DIR_OUT,
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};
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/*
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* struct gpio_pin_status - structure describing a GPIO status
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* @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out
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* @value: Configures status of the gpio as 0(low) or 1(high)
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*/
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struct gpio_mockup_line_status {
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int dir;
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bool value;
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};
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struct gpio_mockup_irq_context {
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struct irq_work work;
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int irq;
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};
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struct gpio_mockup_chip {
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struct gpio_chip gc;
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struct gpio_mockup_line_status *lines;
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struct gpio_mockup_irq_context irq_ctx;
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struct dentry *dbg_dir;
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};
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struct gpio_mockup_dbgfs_private {
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struct gpio_mockup_chip *chip;
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struct gpio_desc *desc;
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int offset;
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};
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static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
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static int gpio_mockup_params_nr;
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module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400);
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static bool gpio_mockup_named_lines;
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module_param_named(gpio_mockup_named_lines,
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gpio_mockup_named_lines, bool, 0400);
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static const char gpio_mockup_name_start = 'A';
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static struct dentry *gpio_mockup_dbg_dir;
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static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
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{
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struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
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return chip->lines[offset].value;
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}
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static void gpio_mockup_set(struct gpio_chip *gc, unsigned int offset,
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int value)
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{
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struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
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chip->lines[offset].value = !!value;
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}
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static int gpio_mockup_dirout(struct gpio_chip *gc, unsigned int offset,
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int value)
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{
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struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
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gpio_mockup_set(gc, offset, value);
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chip->lines[offset].dir = DIR_OUT;
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return 0;
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}
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static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset)
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{
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struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
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chip->lines[offset].dir = DIR_IN;
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return 0;
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}
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static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset)
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{
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struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
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return chip->lines[offset].dir;
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}
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static int gpio_mockup_name_lines(struct device *dev,
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struct gpio_mockup_chip *chip)
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{
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struct gpio_chip *gc = &chip->gc;
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char **names;
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int i;
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names = devm_kzalloc(dev, sizeof(char *) * gc->ngpio, GFP_KERNEL);
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if (!names)
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return -ENOMEM;
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for (i = 0; i < gc->ngpio; i++) {
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names[i] = devm_kasprintf(dev, GFP_KERNEL,
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"%s-%d", gc->label, i);
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if (!names[i])
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return -ENOMEM;
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}
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gc->names = (const char *const *)names;
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return 0;
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}
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static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset)
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{
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return chip->irq_base + offset;
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}
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/*
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* While we should generally support irqmask and irqunmask, this driver is
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* for testing purposes only so we don't care.
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*/
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static void gpio_mockup_irqmask(struct irq_data *d) { }
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static void gpio_mockup_irqunmask(struct irq_data *d) { }
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static struct irq_chip gpio_mockup_irqchip = {
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.name = GPIO_MOCKUP_NAME,
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.irq_mask = gpio_mockup_irqmask,
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.irq_unmask = gpio_mockup_irqunmask,
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};
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static void gpio_mockup_handle_irq(struct irq_work *work)
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{
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struct gpio_mockup_irq_context *irq_ctx;
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irq_ctx = container_of(work, struct gpio_mockup_irq_context, work);
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handle_simple_irq(irq_to_desc(irq_ctx->irq));
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}
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static int gpio_mockup_irqchip_setup(struct device *dev,
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struct gpio_mockup_chip *chip)
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{
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struct gpio_chip *gc = &chip->gc;
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int irq_base, i;
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irq_base = irq_alloc_descs(-1, 0, gc->ngpio, 0);
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if (irq_base < 0)
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return irq_base;
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gc->irq_base = irq_base;
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gc->irqchip = &gpio_mockup_irqchip;
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for (i = 0; i < gc->ngpio; i++) {
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irq_set_chip(irq_base + i, gc->irqchip);
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irq_set_handler(irq_base + i, &handle_simple_irq);
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irq_modify_status(irq_base + i,
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IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
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}
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init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq);
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return 0;
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}
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static ssize_t gpio_mockup_event_write(struct file *file,
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const char __user *usr_buf,
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size_t size, loff_t *ppos)
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{
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struct gpio_mockup_dbgfs_private *priv;
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struct gpio_mockup_chip *chip;
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struct seq_file *sfile;
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struct gpio_desc *desc;
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struct gpio_chip *gc;
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int val;
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char buf;
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sfile = file->private_data;
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priv = sfile->private;
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desc = priv->desc;
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chip = priv->chip;
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gc = &chip->gc;
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if (copy_from_user(&buf, usr_buf, 1))
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return -EFAULT;
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if (buf == '0')
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val = 0;
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else if (buf == '1')
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val = 1;
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else
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return -EINVAL;
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gpiod_set_value_cansleep(desc, val);
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priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
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irq_work_queue(&priv->chip->irq_ctx.work);
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return size;
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}
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static int gpio_mockup_event_open(struct inode *inode, struct file *file)
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{
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return single_open(file, NULL, inode->i_private);
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}
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static const struct file_operations gpio_mockup_event_ops = {
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.owner = THIS_MODULE,
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.open = gpio_mockup_event_open,
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.write = gpio_mockup_event_write,
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.llseek = no_llseek,
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};
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static void gpio_mockup_debugfs_setup(struct device *dev,
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struct gpio_mockup_chip *chip)
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{
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struct gpio_mockup_dbgfs_private *priv;
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struct dentry *evfile;
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struct gpio_chip *gc;
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char *name;
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int i;
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gc = &chip->gc;
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chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir);
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if (!chip->dbg_dir)
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goto err;
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for (i = 0; i < gc->ngpio; i++) {
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name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
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if (!name)
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goto err;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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goto err;
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priv->chip = chip;
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priv->offset = i;
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priv->desc = &gc->gpiodev->descs[i];
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evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
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&gpio_mockup_event_ops);
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if (!evfile)
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goto err;
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}
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return;
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err:
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dev_err(dev, "error creating debugfs directory\n");
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}
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static int gpio_mockup_add(struct device *dev,
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struct gpio_mockup_chip *chip,
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const char *name, int base, int ngpio)
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{
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struct gpio_chip *gc = &chip->gc;
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int ret;
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gc->base = base;
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gc->ngpio = ngpio;
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gc->label = name;
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gc->owner = THIS_MODULE;
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gc->parent = dev;
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gc->get = gpio_mockup_get;
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gc->set = gpio_mockup_set;
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gc->direction_output = gpio_mockup_dirout;
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gc->direction_input = gpio_mockup_dirin;
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gc->get_direction = gpio_mockup_get_direction;
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gc->to_irq = gpio_mockup_to_irq;
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chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,
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GFP_KERNEL);
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if (!chip->lines)
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return -ENOMEM;
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if (gpio_mockup_named_lines) {
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ret = gpio_mockup_name_lines(dev, chip);
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if (ret)
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return ret;
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}
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ret = gpio_mockup_irqchip_setup(dev, chip);
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if (ret)
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return ret;
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ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
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if (ret)
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return ret;
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if (gpio_mockup_dbg_dir)
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gpio_mockup_debugfs_setup(dev, chip);
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return 0;
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}
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static int gpio_mockup_probe(struct platform_device *pdev)
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{
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struct gpio_mockup_chip *chips;
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struct device *dev = &pdev->dev;
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int ret, i, base, ngpio;
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char *chip_name;
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if (gpio_mockup_params_nr < 2)
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return -EINVAL;
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chips = devm_kzalloc(dev,
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sizeof(*chips) * (gpio_mockup_params_nr >> 1),
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GFP_KERNEL);
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if (!chips)
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return -ENOMEM;
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platform_set_drvdata(pdev, chips);
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for (i = 0; i < gpio_mockup_params_nr >> 1; i++) {
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base = gpio_mockup_ranges[i * 2];
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if (base == -1)
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ngpio = gpio_mockup_ranges[i * 2 + 1];
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else
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ngpio = gpio_mockup_ranges[i * 2 + 1] - base;
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if (ngpio >= 0) {
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chip_name = devm_kasprintf(dev, GFP_KERNEL,
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"%s-%c", GPIO_MOCKUP_NAME,
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gpio_mockup_name_start + i);
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if (!chip_name)
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return -ENOMEM;
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ret = gpio_mockup_add(dev, &chips[i],
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chip_name, base, ngpio);
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} else {
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ret = -1;
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}
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if (ret) {
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dev_err(dev, "gpio<%d..%d> add failed\n",
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base, base < 0 ? ngpio : base + ngpio);
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return ret;
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}
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dev_info(dev, "gpio<%d..%d> add successful!",
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base, base + ngpio);
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}
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return 0;
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}
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static int gpio_mockup_remove(struct platform_device *pdev)
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{
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struct gpio_mockup_chip *chips;
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int i;
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chips = platform_get_drvdata(pdev);
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for (i = 0; i < gpio_mockup_params_nr >> 1; i++)
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irq_free_descs(chips[i].gc.irq_base, chips[i].gc.ngpio);
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return 0;
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}
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static struct platform_driver gpio_mockup_driver = {
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.driver = {
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.name = GPIO_MOCKUP_NAME,
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},
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.probe = gpio_mockup_probe,
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.remove = gpio_mockup_remove,
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};
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static struct platform_device *pdev;
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static int __init mock_device_init(void)
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{
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int err;
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gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
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if (!gpio_mockup_dbg_dir)
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pr_err("%s: error creating debugfs directory\n",
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GPIO_MOCKUP_NAME);
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pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1);
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if (!pdev)
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return -ENOMEM;
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err = platform_device_add(pdev);
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if (err) {
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platform_device_put(pdev);
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return err;
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}
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err = platform_driver_register(&gpio_mockup_driver);
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if (err) {
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platform_device_unregister(pdev);
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return err;
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}
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return 0;
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}
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static void __exit mock_device_exit(void)
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{
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debugfs_remove_recursive(gpio_mockup_dbg_dir);
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platform_driver_unregister(&gpio_mockup_driver);
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platform_device_unregister(pdev);
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}
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module_init(mock_device_init);
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module_exit(mock_device_exit);
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MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
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MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>");
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MODULE_DESCRIPTION("GPIO Testing driver");
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MODULE_LICENSE("GPL v2");
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