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cb32389cb9
By the time request_region is called in the ACCES 104-IDIO-16 GPIO driver, a corresponding device structure has already been allocated. The devm_request_region function should be used to help simplify the cleanup code and reduce the possible points of failure. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
312 lines
7.7 KiB
C
312 lines
7.7 KiB
C
/*
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* GPIO driver for the ACCES 104-IDIO-16 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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#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/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/platform_device.h>
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#include <linux/spinlock.h>
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static unsigned idio_16_base;
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module_param(idio_16_base, uint, 0);
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MODULE_PARM_DESC(idio_16_base, "ACCES 104-IDIO-16 base address");
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static unsigned idio_16_irq;
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module_param(idio_16_irq, uint, 0);
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MODULE_PARM_DESC(idio_16_irq, "ACCES 104-IDIO-16 interrupt line number");
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/**
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* struct idio_16_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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* @irq_mask: I/O bits affected by interrupts
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* @base: base port address of the GPIO device
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* @irq: Interrupt line number
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* @out_state: output bits state
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*/
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struct idio_16_gpio {
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struct gpio_chip chip;
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spinlock_t lock;
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unsigned long irq_mask;
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unsigned base;
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unsigned irq;
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unsigned out_state;
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};
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static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
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{
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if (offset > 15)
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return 1;
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return 0;
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}
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static int idio_16_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 idio_16_gpio_direction_output(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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chip->set(chip, offset, value);
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return 0;
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}
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static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
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const unsigned mask = BIT(offset-16);
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if (offset < 16)
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return -EINVAL;
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if (offset < 24)
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return !!(inb(idio16gpio->base + 1) & mask);
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return !!(inb(idio16gpio->base + 5) & (mask>>8));
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}
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static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
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const unsigned mask = BIT(offset);
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unsigned long flags;
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if (offset > 15)
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return;
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spin_lock_irqsave(&idio16gpio->lock, flags);
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if (value)
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idio16gpio->out_state |= mask;
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else
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idio16gpio->out_state &= ~mask;
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if (offset > 7)
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outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);
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else
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outb(idio16gpio->out_state, idio16gpio->base);
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spin_unlock_irqrestore(&idio16gpio->lock, flags);
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}
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static void idio_16_irq_ack(struct irq_data *data)
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{
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}
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static void idio_16_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 idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
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const unsigned long mask = BIT(irqd_to_hwirq(data));
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unsigned long flags;
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idio16gpio->irq_mask &= ~mask;
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if (!idio16gpio->irq_mask) {
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spin_lock_irqsave(&idio16gpio->lock, flags);
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outb(0, idio16gpio->base + 2);
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spin_unlock_irqrestore(&idio16gpio->lock, flags);
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}
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}
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static void idio_16_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 idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
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const unsigned long mask = BIT(irqd_to_hwirq(data));
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const unsigned long prev_irq_mask = idio16gpio->irq_mask;
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unsigned long flags;
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idio16gpio->irq_mask |= mask;
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if (!prev_irq_mask) {
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spin_lock_irqsave(&idio16gpio->lock, flags);
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inb(idio16gpio->base + 2);
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spin_unlock_irqrestore(&idio16gpio->lock, flags);
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}
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}
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static int idio_16_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 idio_16_irqchip = {
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.name = "104-idio-16",
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.irq_ack = idio_16_irq_ack,
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.irq_mask = idio_16_irq_mask,
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.irq_unmask = idio_16_irq_unmask,
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.irq_set_type = idio_16_irq_set_type
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};
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static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
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{
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struct idio_16_gpio *const idio16gpio = dev_id;
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struct gpio_chip *const chip = &idio16gpio->chip;
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int gpio;
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for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio)
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generic_handle_irq(irq_find_mapping(chip->irqdomain, gpio));
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spin_lock(&idio16gpio->lock);
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outb(0, idio16gpio->base + 1);
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spin_unlock(&idio16gpio->lock);
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return IRQ_HANDLED;
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}
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static int __init idio_16_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct idio_16_gpio *idio16gpio;
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const unsigned base = idio_16_base;
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const unsigned extent = 8;
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const char *const name = dev_name(dev);
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int err;
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const unsigned irq = idio_16_irq;
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idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
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if (!idio16gpio)
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return -ENOMEM;
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if (!devm_request_region(dev, base, extent, name)) {
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dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
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base, base + extent);
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return -EBUSY;
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}
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idio16gpio->chip.label = name;
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idio16gpio->chip.parent = dev;
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idio16gpio->chip.owner = THIS_MODULE;
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idio16gpio->chip.base = -1;
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idio16gpio->chip.ngpio = 32;
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idio16gpio->chip.get_direction = idio_16_gpio_get_direction;
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idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
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idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
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idio16gpio->chip.get = idio_16_gpio_get;
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idio16gpio->chip.set = idio_16_gpio_set;
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idio16gpio->base = base;
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idio16gpio->irq = irq;
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idio16gpio->out_state = 0xFFFF;
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spin_lock_init(&idio16gpio->lock);
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dev_set_drvdata(dev, idio16gpio);
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err = gpiochip_add_data(&idio16gpio->chip, idio16gpio);
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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 + 2);
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outb(0, base + 1);
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err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_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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goto err_gpiochip_remove;
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}
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err = request_irq(irq, idio_16_irq_handler, 0, name, idio16gpio);
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if (err) {
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dev_err(dev, "IRQ handler registering failed (%d)\n", err);
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goto err_gpiochip_remove;
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}
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return 0;
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err_gpiochip_remove:
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gpiochip_remove(&idio16gpio->chip);
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return err;
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}
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static int idio_16_remove(struct platform_device *pdev)
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{
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struct idio_16_gpio *const idio16gpio = platform_get_drvdata(pdev);
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free_irq(idio16gpio->irq, idio16gpio);
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gpiochip_remove(&idio16gpio->chip);
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return 0;
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}
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static struct platform_device *idio_16_device;
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static struct platform_driver idio_16_driver = {
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.driver = {
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.name = "104-idio-16"
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},
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.remove = idio_16_remove
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};
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static void __exit idio_16_exit(void)
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{
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platform_device_unregister(idio_16_device);
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platform_driver_unregister(&idio_16_driver);
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}
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static int __init idio_16_init(void)
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{
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int err;
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idio_16_device = platform_device_alloc(idio_16_driver.driver.name, -1);
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if (!idio_16_device)
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return -ENOMEM;
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err = platform_device_add(idio_16_device);
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if (err)
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goto err_platform_device;
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err = platform_driver_probe(&idio_16_driver, idio_16_probe);
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if (err)
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goto err_platform_driver;
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return 0;
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err_platform_driver:
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platform_device_del(idio_16_device);
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err_platform_device:
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platform_device_put(idio_16_device);
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return err;
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}
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module_init(idio_16_init);
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module_exit(idio_16_exit);
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MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
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MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
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MODULE_LICENSE("GPL v2");
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