233 lines
5.5 KiB
C
233 lines
5.5 KiB
C
/*
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* GE PIO2 GPIO Driver
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*
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* Author: Martyn Welch <martyn.welch@ge.com>
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* Copyright 2009 GE Intelligent Platforms Embedded Systems, Inc.
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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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#include <linux/version.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/ctype.h>
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#include <linux/gpio.h>
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#include <linux/slab.h>
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#include "../vme.h"
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#include "vme_pio2.h"
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static const char driver_name[] = "pio2_gpio";
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static struct pio2_card *gpio_to_pio2_card(struct gpio_chip *chip)
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{
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return container_of(chip, struct pio2_card, gc);
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}
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static int pio2_gpio_get(struct gpio_chip *chip, unsigned int offset)
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{
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u8 reg;
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int retval;
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struct pio2_card *card = gpio_to_pio2_card(chip);
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if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) |
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(card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) {
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dev_err(&card->vdev->dev, "Channel not available as input\n");
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return 0;
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}
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retval = vme_master_read(card->window, ®, 1,
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PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]);
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if (retval < 0) {
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dev_err(&card->vdev->dev, "Unable to read from GPIO\n");
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return 0;
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}
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/*
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* Remember, input on channels configured as both input and output
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* are inverted!
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*/
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if (reg & PIO2_CHANNEL_BIT[offset]) {
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if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH)
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return 0;
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else
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return 1;
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} else {
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if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH)
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return 1;
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else
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return 0;
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}
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}
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static void pio2_gpio_set(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
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u8 reg;
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int retval;
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struct pio2_card *card = gpio_to_pio2_card(chip);
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if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) |
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(card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) {
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dev_err(&card->vdev->dev, "Channel not availabe as output\n");
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return;
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}
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if (value)
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reg = card->bank[PIO2_CHANNEL_BANK[offset]].value |
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PIO2_CHANNEL_BIT[offset];
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else
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reg = card->bank[PIO2_CHANNEL_BANK[offset]].value &
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~PIO2_CHANNEL_BIT[offset];
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retval = vme_master_write(card->window, ®, 1,
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PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]);
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if (retval < 0) {
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dev_err(&card->vdev->dev, "Unable to write to GPIO\n");
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return;
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}
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card->bank[PIO2_CHANNEL_BANK[offset]].value = reg;
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}
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/* Directionality configured at board build - send appropriate response */
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static int pio2_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
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{
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int data;
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struct pio2_card *card = gpio_to_pio2_card(chip);
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if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) |
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(card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) {
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dev_err(&card->vdev->dev,
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"Channel directionality not configurable at runtine\n");
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data = -EINVAL;
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} else {
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data = 0;
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}
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return data;
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}
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/* Directionality configured at board build - send appropriate response */
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static int pio2_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
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{
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int data;
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struct pio2_card *card = gpio_to_pio2_card(chip);
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if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) |
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(card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) {
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dev_err(&card->vdev->dev,
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"Channel directionality not configurable at runtine\n");
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data = -EINVAL;
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} else {
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data = 0;
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}
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return data;
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}
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/*
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* We return whether this has been successful - this is used in the probe to
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* ensure we have a valid card.
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*/
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int pio2_gpio_reset(struct pio2_card *card)
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{
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int retval = 0;
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int i, j;
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u8 data = 0;
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/* Zero output registers */
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for (i = 0; i < 4; i++) {
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retval = vme_master_write(card->window, &data, 1,
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PIO2_REGS_DATA[i]);
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if (retval < 0)
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return retval;
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card->bank[i].value = 0;
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}
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/* Set input interrupt masks */
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for (i = 0; i < 4; i++) {
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retval = vme_master_write(card->window, &data, 1,
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PIO2_REGS_INT_MASK[i * 2]);
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if (retval < 0)
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return retval;
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retval = vme_master_write(card->window, &data, 1,
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PIO2_REGS_INT_MASK[(i * 2) + 1]);
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if (retval < 0)
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return retval;
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for (j = 0; j < 8; j++)
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card->bank[i].irq[j] = NONE;
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}
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/* Ensure all I/O interrupts are cleared */
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for (i = 0; i < 4; i++) {
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do {
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retval = vme_master_read(card->window, &data, 1,
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PIO2_REGS_INT_STAT[i]);
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if (retval < 0)
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return retval;
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} while (data != 0);
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}
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return 0;
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}
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int __devinit pio2_gpio_init(struct pio2_card *card)
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{
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int retval = 0;
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char *label;
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label = kmalloc(PIO2_NUM_CHANNELS, GFP_KERNEL);
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if (label == NULL) {
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dev_err(&card->vdev->dev, "Unable to allocate GPIO label\n");
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return -ENOMEM;
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}
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sprintf(label, "%s@%s", driver_name, dev_name(&card->vdev->dev));
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card->gc.label = label;
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card->gc.ngpio = PIO2_NUM_CHANNELS;
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/* Dynamic allocation of base */
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card->gc.base = -1;
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/* Setup pointers to chip functions */
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card->gc.direction_input = pio2_gpio_dir_in;
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card->gc.direction_output = pio2_gpio_dir_out;
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card->gc.get = pio2_gpio_get;
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card->gc.set = pio2_gpio_set;
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/* This function adds a memory mapped GPIO chip */
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retval = gpiochip_add(&(card->gc));
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if (retval) {
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dev_err(&card->vdev->dev, "Unable to register GPIO\n");
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kfree(card->gc.label);
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}
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return retval;
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};
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void pio2_gpio_exit(struct pio2_card *card)
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{
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const char *label = card->gc.label;
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if (gpiochip_remove(&(card->gc)))
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dev_err(&card->vdev->dev, "Failed to remove GPIO");
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kfree(label);
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}
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