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-----BEGIN PGP SIGNATURE----- iQIVAwUAWPiW6vSw1s6N8H32AQLOrw/+NTqGf7bjq+64YKS6NfR0XDgE+wNJltGO ck7zJW3NHIg76RNu8s0I9xg5aVmwizz3Z5DGROZquaolnezux4tQihZ3AFyxIzLc +Y3WHYagcML7yFfjl/WznCLRD5EW3yPln4lCvQO0nW/xICRYeRI057JaIbi2Dtek BhcXt3c4AjXDLdYJkgtHV3p2R2mt8hcdFdWqqx6s7JaIThZNRGNzxAgtbcB9k5IW HVG9ZEIL73VBYWHrYivzjHYF5rBnNCPt87eOwDQeTOSkhv8te+u9k+bH8vxZw1T0 XUtDrLBndKiuVo2GUfLkkF8LItx3Q9eLCJYy0joaIliyPqTEsPx9KjQ+Af0cxS9s ZPCZ5SYf96stKmDeL5xaMfrAmeyVHJ4lc4JTOqdzbIT8blsOSfYO/03p0ALShSDv /RQLaKGlf8Bjoy8PwKFcXb4sIDufcd/U1Av/EMFXxOfgN/u2JUkGKq6EaIM5B68L fHPje+aR9VNELPmPjwNOWtmN4I79EH3EItQf7zv0KG+UeKhcHLx/EAcSJ3ZRKEkH Lathg7pPOEJGArPiVO79TZzBG01ADn1aiwv65XObMzNZ+54xI/mN/Y1DNF/kL5jU XzvNzEjFt8mwMIZGVNdAt4+pDyMfIZGZSyUkSRKFnaQZMIvQrfQIU9RLBYLX5eOx +/p0VkIwDpg= =lbS7 -----END PGP SIGNATURE----- Merge tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull hw lockdown support from David Howells: "Annotation of module parameters that configure hardware resources including ioports, iomem addresses, irq lines and dma channels. This allows a future patch to prohibit the use of such module parameters to prevent that hardware from being abused to gain access to the running kernel image as part of locking the kernel down under UEFI secure boot conditions. Annotations are made by changing: module_param(n, t, p) module_param_named(n, v, t, p) module_param_array(n, t, m, p) to: module_param_hw(n, t, hwtype, p) module_param_hw_named(n, v, t, hwtype, p) module_param_hw_array(n, t, hwtype, m, p) where the module parameter refers to a hardware setting hwtype specifies the type of the resource being configured. This can be one of: ioport Module parameter configures an I/O port iomem Module parameter configures an I/O mem address ioport_or_iomem Module parameter could be either (runtime set) irq Module parameter configures an I/O port dma Module parameter configures a DMA channel dma_addr Module parameter configures a DMA buffer address other Module parameter configures some other value Note that the hwtype is compile checked, but not currently stored (the lockdown code probably won't require it). It is, however, there for future use. A bonus is that the hwtype can also be used for grepping. The intention is for the kernel to ignore or reject attempts to set annotated module parameters if lockdown is enabled. This applies to options passed on the boot command line, passed to insmod/modprobe or direct twiddling in /sys/module/ parameter files. The module initialisation then needs to handle the parameter not being set, by (1) giving an error, (2) probing for a value or (3) using a reasonable default. What I can't do is just reject a module out of hand because it may take a hardware setting in the module parameters. Some important modules, some ipmi stuff for instance, both probe for hardware and allow hardware to be manually specified; if the driver is aborts with any error, you don't get any ipmi hardware. Further, trying to do this entirely in the module initialisation code doesn't protect against sysfs twiddling. [!] Note that in and of itself, this series of patches should have no effect on the the size of the kernel or code execution - that is left to a patch in the next series to effect. It does mark annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in an already existing field" * tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits) Annotate hardware config module parameters in sound/pci/ Annotate hardware config module parameters in sound/oss/ Annotate hardware config module parameters in sound/isa/ Annotate hardware config module parameters in sound/drivers/ Annotate hardware config module parameters in fs/pstore/ Annotate hardware config module parameters in drivers/watchdog/ Annotate hardware config module parameters in drivers/video/ Annotate hardware config module parameters in drivers/tty/ Annotate hardware config module parameters in drivers/staging/vme/ Annotate hardware config module parameters in drivers/staging/speakup/ Annotate hardware config module parameters in drivers/staging/media/ Annotate hardware config module parameters in drivers/scsi/ Annotate hardware config module parameters in drivers/pcmcia/ Annotate hardware config module parameters in drivers/pci/hotplug/ Annotate hardware config module parameters in drivers/parport/ Annotate hardware config module parameters in drivers/net/wireless/ Annotate hardware config module parameters in drivers/net/wan/ Annotate hardware config module parameters in drivers/net/irda/ Annotate hardware config module parameters in drivers/net/hamradio/ Annotate hardware config module parameters in drivers/net/ethernet/ ...
301 lines
8 KiB
C
301 lines
8 KiB
C
/*
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* GPIO driver for the ACCES 104-IDI-48 family
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* Copyright (C) 2015 William Breathitt Gray
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* This driver supports the following ACCES devices: 104-IDI-48A,
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* 104-IDI-48AC, 104-IDI-48B, and 104-IDI-48BC.
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*/
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/gpio/driver.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <linux/interrupt.h>
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#include <linux/irqdesc.h>
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#include <linux/isa.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/spinlock.h>
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#define IDI_48_EXTENT 8
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#define MAX_NUM_IDI_48 max_num_isa_dev(IDI_48_EXTENT)
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static unsigned int base[MAX_NUM_IDI_48];
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static unsigned int num_idi_48;
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module_param_hw_array(base, uint, ioport, &num_idi_48, 0);
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MODULE_PARM_DESC(base, "ACCES 104-IDI-48 base addresses");
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static unsigned int irq[MAX_NUM_IDI_48];
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module_param_hw_array(irq, uint, irq, NULL, 0);
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MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers");
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/**
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* struct idi_48_gpio - GPIO device private data structure
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* @chip: instance of the gpio_chip
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* @lock: synchronization lock to prevent I/O race conditions
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* @ack_lock: synchronization lock to prevent IRQ handler race conditions
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* @irq_mask: input bits affected by interrupts
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* @base: base port address of the GPIO device
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* @cos_enb: Change-Of-State IRQ enable boundaries mask
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*/
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struct idi_48_gpio {
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struct gpio_chip chip;
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raw_spinlock_t lock;
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spinlock_t ack_lock;
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unsigned char irq_mask[6];
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unsigned base;
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unsigned char cos_enb;
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};
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static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
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{
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return 1;
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}
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static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
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{
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return 0;
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}
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static int idi_48_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
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unsigned i;
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const unsigned register_offset[6] = { 0, 1, 2, 4, 5, 6 };
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unsigned base_offset;
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unsigned mask;
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for (i = 0; i < 48; i += 8)
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if (offset < i + 8) {
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base_offset = register_offset[i / 8];
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mask = BIT(offset - i);
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return !!(inb(idi48gpio->base + base_offset) & mask);
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}
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/* The following line should never execute since offset < 48 */
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return 0;
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}
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static void idi_48_irq_ack(struct irq_data *data)
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{
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}
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static void idi_48_irq_mask(struct irq_data *data)
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{
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struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
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struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
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const unsigned offset = irqd_to_hwirq(data);
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unsigned i;
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unsigned mask;
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unsigned boundary;
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unsigned long flags;
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for (i = 0; i < 48; i += 8)
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if (offset < i + 8) {
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mask = BIT(offset - i);
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boundary = i / 8;
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idi48gpio->irq_mask[boundary] &= ~mask;
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if (!idi48gpio->irq_mask[boundary]) {
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idi48gpio->cos_enb &= ~BIT(boundary);
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raw_spin_lock_irqsave(&idi48gpio->lock, flags);
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outb(idi48gpio->cos_enb, idi48gpio->base + 7);
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raw_spin_unlock_irqrestore(&idi48gpio->lock,
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flags);
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}
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return;
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}
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}
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static void idi_48_irq_unmask(struct irq_data *data)
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{
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struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
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struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
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const unsigned offset = irqd_to_hwirq(data);
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unsigned i;
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unsigned mask;
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unsigned boundary;
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unsigned prev_irq_mask;
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unsigned long flags;
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for (i = 0; i < 48; i += 8)
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if (offset < i + 8) {
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mask = BIT(offset - i);
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boundary = i / 8;
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prev_irq_mask = idi48gpio->irq_mask[boundary];
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idi48gpio->irq_mask[boundary] |= mask;
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if (!prev_irq_mask) {
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idi48gpio->cos_enb |= BIT(boundary);
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raw_spin_lock_irqsave(&idi48gpio->lock, flags);
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outb(idi48gpio->cos_enb, idi48gpio->base + 7);
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raw_spin_unlock_irqrestore(&idi48gpio->lock,
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flags);
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}
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return;
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}
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}
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static int idi_48_irq_set_type(struct irq_data *data, unsigned flow_type)
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{
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/* The only valid irq types are none and both-edges */
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if (flow_type != IRQ_TYPE_NONE &&
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(flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH)
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return -EINVAL;
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return 0;
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}
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static struct irq_chip idi_48_irqchip = {
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.name = "104-idi-48",
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.irq_ack = idi_48_irq_ack,
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.irq_mask = idi_48_irq_mask,
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.irq_unmask = idi_48_irq_unmask,
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.irq_set_type = idi_48_irq_set_type
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};
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static irqreturn_t idi_48_irq_handler(int irq, void *dev_id)
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{
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struct idi_48_gpio *const idi48gpio = dev_id;
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unsigned long cos_status;
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unsigned long boundary;
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unsigned long irq_mask;
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unsigned long bit_num;
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unsigned long gpio;
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struct gpio_chip *const chip = &idi48gpio->chip;
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spin_lock(&idi48gpio->ack_lock);
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raw_spin_lock(&idi48gpio->lock);
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cos_status = inb(idi48gpio->base + 7);
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raw_spin_unlock(&idi48gpio->lock);
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/* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */
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if (cos_status & BIT(6)) {
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spin_unlock(&idi48gpio->ack_lock);
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return IRQ_NONE;
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}
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/* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */
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cos_status &= 0x3F;
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for_each_set_bit(boundary, &cos_status, 6) {
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irq_mask = idi48gpio->irq_mask[boundary];
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for_each_set_bit(bit_num, &irq_mask, 8) {
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gpio = bit_num + boundary * 8;
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generic_handle_irq(irq_find_mapping(chip->irqdomain,
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gpio));
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}
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}
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spin_unlock(&idi48gpio->ack_lock);
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return IRQ_HANDLED;
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}
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#define IDI48_NGPIO 48
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static const char *idi48_names[IDI48_NGPIO] = {
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"Bit 0 A", "Bit 1 A", "Bit 2 A", "Bit 3 A", "Bit 4 A", "Bit 5 A",
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"Bit 6 A", "Bit 7 A", "Bit 8 A", "Bit 9 A", "Bit 10 A", "Bit 11 A",
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"Bit 12 A", "Bit 13 A", "Bit 14 A", "Bit 15 A", "Bit 16 A", "Bit 17 A",
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"Bit 18 A", "Bit 19 A", "Bit 20 A", "Bit 21 A", "Bit 22 A", "Bit 23 A",
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"Bit 0 B", "Bit 1 B", "Bit 2 B", "Bit 3 B", "Bit 4 B", "Bit 5 B",
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"Bit 6 B", "Bit 7 B", "Bit 8 B", "Bit 9 B", "Bit 10 B", "Bit 11 B",
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"Bit 12 B", "Bit 13 B", "Bit 14 B", "Bit 15 B", "Bit 16 B", "Bit 17 B",
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"Bit 18 B", "Bit 19 B", "Bit 20 B", "Bit 21 B", "Bit 22 B", "Bit 23 B"
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};
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static int idi_48_probe(struct device *dev, unsigned int id)
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{
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struct idi_48_gpio *idi48gpio;
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const char *const name = dev_name(dev);
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int err;
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idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL);
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if (!idi48gpio)
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return -ENOMEM;
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if (!devm_request_region(dev, base[id], IDI_48_EXTENT, name)) {
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dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
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base[id], base[id] + IDI_48_EXTENT);
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return -EBUSY;
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}
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idi48gpio->chip.label = name;
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idi48gpio->chip.parent = dev;
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idi48gpio->chip.owner = THIS_MODULE;
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idi48gpio->chip.base = -1;
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idi48gpio->chip.ngpio = IDI48_NGPIO;
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idi48gpio->chip.names = idi48_names;
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idi48gpio->chip.get_direction = idi_48_gpio_get_direction;
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idi48gpio->chip.direction_input = idi_48_gpio_direction_input;
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idi48gpio->chip.get = idi_48_gpio_get;
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idi48gpio->base = base[id];
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raw_spin_lock_init(&idi48gpio->lock);
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spin_lock_init(&idi48gpio->ack_lock);
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err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio);
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if (err) {
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dev_err(dev, "GPIO registering failed (%d)\n", err);
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return err;
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}
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/* Disable IRQ by default */
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outb(0, base[id] + 7);
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inb(base[id] + 7);
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err = gpiochip_irqchip_add(&idi48gpio->chip, &idi_48_irqchip, 0,
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handle_edge_irq, IRQ_TYPE_NONE);
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if (err) {
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dev_err(dev, "Could not add irqchip (%d)\n", err);
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return err;
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}
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err = devm_request_irq(dev, irq[id], idi_48_irq_handler, IRQF_SHARED,
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name, idi48gpio);
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if (err) {
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dev_err(dev, "IRQ handler registering failed (%d)\n", err);
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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 struct isa_driver idi_48_driver = {
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.probe = idi_48_probe,
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.driver = {
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.name = "104-idi-48"
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},
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};
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module_isa_driver(idi_48_driver, num_idi_48);
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MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
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MODULE_DESCRIPTION("ACCES 104-IDI-48 GPIO driver");
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MODULE_LICENSE("GPL v2");
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