cregit-Linux how code gets into the kernel

Release 4.11 drivers/input/keyboard/gpio_keys.c

/*
 * Driver for keys on GPIO lines capable of generating interrupts.
 *
 * Copyright 2005 Phil Blundell
 * Copyright 2010, 2011 David Jander <david@protonic.nl>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/gpio_keys.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>


struct gpio_button_data {
	
const struct gpio_keys_button *button;
	
struct input_dev *input;
	
struct gpio_desc *gpiod;

	
unsigned short *code;

	
struct timer_list release_timer;
	
unsigned int release_delay;	/* in msecs, for IRQ-only buttons */

	
struct delayed_work work;
	
unsigned int software_debounce;	/* in msecs, for GPIO-driven buttons */

	
unsigned int irq;
	
spinlock_t lock;
	
bool disabled;
	
bool key_pressed;
};


struct gpio_keys_drvdata {
	
const struct gpio_keys_platform_data *pdata;
	
struct input_dev *input;
	
struct mutex disable_lock;
	
unsigned short *keymap;
	
struct gpio_button_data data[0];
};

/*
 * SYSFS interface for enabling/disabling keys and switches:
 *
 * There are 4 attributes under /sys/devices/platform/gpio-keys/
 *      keys [ro]              - bitmap of keys (EV_KEY) which can be
 *                               disabled
 *      switches [ro]          - bitmap of switches (EV_SW) which can be
 *                               disabled
 *      disabled_keys [rw]     - bitmap of keys currently disabled
 *      disabled_switches [rw] - bitmap of switches currently disabled
 *
 * Userland can change these values and hence disable event generation
 * for each key (or switch). Disabling a key means its interrupt line
 * is disabled.
 *
 * For example, if we have following switches set up as gpio-keys:
 *      SW_DOCK = 5
 *      SW_CAMERA_LENS_COVER = 9
 *      SW_KEYPAD_SLIDE = 10
 *      SW_FRONT_PROXIMITY = 11
 * This is read from switches:
 *      11-9,5
 * Next we want to disable proximity (11) and dock (5), we write:
 *      11,5
 * to file disabled_switches. Now proximity and dock IRQs are disabled.
 * This can be verified by reading the file disabled_switches:
 *      11,5
 * If we now want to enable proximity (11) switch we write:
 *      5
 * to disabled_switches.
 *
 * We can disable only those keys which don't allow sharing the irq.
 */

/**
 * get_n_events_by_type() - returns maximum number of events per @type
 * @type: type of button (%EV_KEY, %EV_SW)
 *
 * Return value of this function can be used to allocate bitmap
 * large enough to hold all bits for given type.
 */

static int get_n_events_by_type(int type) { BUG_ON(type != EV_SW && type != EV_KEY); return (type == EV_KEY) ? KEY_CNT : SW_CNT; }

Contributors

PersonTokensPropCommitsCommitProp
Mika Westerberg31100.00%1100.00%
Total31100.00%1100.00%

/** * get_bm_events_by_type() - returns bitmap of supported events per @type * @input: input device from which bitmap is retrieved * @type: type of button (%EV_KEY, %EV_SW) * * Return value of this function can be used to allocate bitmap * large enough to hold all bits for given type. */
static const unsigned long *get_bm_events_by_type(struct input_dev *dev, int type) { BUG_ON(type != EV_SW && type != EV_KEY); return (type == EV_KEY) ? dev->keybit : dev->swbit; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov43100.00%1100.00%
Total43100.00%1100.00%

/** * gpio_keys_disable_button() - disables given GPIO button * @bdata: button data for button to be disabled * * Disables button pointed by @bdata. This is done by masking * IRQ line. After this function is called, button won't generate * input events anymore. Note that one can only disable buttons * that don't share IRQs. * * Make sure that @bdata->disable_lock is locked when entering * this function to avoid races when concurrent threads are * disabling buttons at the same time. */
static void gpio_keys_disable_button(struct gpio_button_data *bdata) { if (!bdata->disabled) { /* * Disable IRQ and associated timer/work structure. */ disable_irq(bdata->irq); if (bdata->gpiod) cancel_delayed_work_sync(&bdata->work); else del_timer_sync(&bdata->release_timer); bdata->disabled = true; } }

Contributors

PersonTokensPropCommitsCommitProp
Mika Westerberg4477.19%125.00%
Dmitry Torokhov1119.30%125.00%
Laxman Dewangan11.75%125.00%
Geert Uytterhoeven11.75%125.00%
Total57100.00%4100.00%

/** * gpio_keys_enable_button() - enables given GPIO button * @bdata: button data for button to be disabled * * Enables given button pointed by @bdata. * * Make sure that @bdata->disable_lock is locked when entering * this function to avoid races with concurrent threads trying * to enable the same button at the same time. */
static void gpio_keys_enable_button(struct gpio_button_data *bdata) { if (bdata->disabled) { enable_irq(bdata->irq); bdata->disabled = false; } }

Contributors

PersonTokensPropCommitsCommitProp
Mika Westerberg3196.88%150.00%
Laxman Dewangan13.12%150.00%
Total32100.00%2100.00%

/** * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons * @ddata: pointer to drvdata * @buf: buffer where stringified bitmap is written * @type: button type (%EV_KEY, %EV_SW) * @only_disabled: does caller want only those buttons that are * currently disabled or all buttons that can be * disabled * * This function writes buttons that can be disabled to @buf. If * @only_disabled is true, then @buf contains only those buttons * that are currently disabled. Returns 0 on success or negative * errno on failure. */
static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata, char *buf, unsigned int type, bool only_disabled) { int n_events = get_n_events_by_type(type); unsigned long *bits; ssize_t ret; int i; bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL); if (!bits) return -ENOMEM; for (i = 0; i < ddata->pdata->nbuttons; i++) { struct gpio_button_data *bdata = &ddata->data[i]; if (bdata->button->type != type) continue; if (only_disabled && !bdata->disabled) continue; __set_bit(*bdata->code, bits); } ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits); buf[ret++] = '\n'; buf[ret] = '\0'; kfree(bits); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Mika Westerberg16294.74%125.00%
Tejun Heo52.92%125.00%
Alexandre Pereira da Silva31.75%125.00%
Hans de Goede10.58%125.00%
Total171100.00%4100.00%

/** * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap * @ddata: pointer to drvdata * @buf: buffer from userspace that contains stringified bitmap * @type: button type (%EV_KEY, %EV_SW) * * This function parses stringified bitmap from @buf and disables/enables * GPIO buttons accordingly. Returns 0 on success and negative error * on failure. */
static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata, const char *buf, unsigned int type) { int n_events = get_n_events_by_type(type); const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type); unsigned long *bits; ssize_t error; int i; bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL); if (!bits) return -ENOMEM; error = bitmap_parselist(buf, bits, n_events); if (error) goto out; /* First validate */ if (!bitmap_subset(bits, bitmap, n_events)) { error = -EINVAL; goto out; } for (i = 0; i < ddata->pdata->nbuttons; i++) { struct gpio_button_data *bdata = &ddata->data[i]; if (bdata->button->type != type) continue; if (test_bit(*bdata->code, bits) && !bdata->button->can_disable) { error = -EINVAL; goto out; } } mutex_lock(&ddata->disable_lock); for (i = 0; i < ddata->pdata->nbuttons; i++) { struct gpio_button_data *bdata = &ddata->data[i]; if (bdata->button->type != type) continue; if (test_bit(*bdata->code, bits)) gpio_keys_disable_button(bdata); else gpio_keys_enable_button(bdata); } mutex_unlock(&ddata->disable_lock); out: kfree(bits); return error; }

Contributors

PersonTokensPropCommitsCommitProp
Mika Westerberg24083.92%120.00%
Dmitry Torokhov3712.94%120.00%
Alexandre Pereira da Silva62.10%120.00%
Hans de Goede20.70%120.00%
Dmitry Baryshkov10.35%120.00%
Total286100.00%5100.00%

#define ATTR_SHOW_FN(name, type, only_disabled) \ static ssize_t gpio_keys_show_##name(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct platform_device *pdev = to_platform_device(dev); \ struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \ \ return gpio_keys_attr_show_helper(ddata, buf, \ type, only_disabled); \ } ATTR_SHOW_FN(keys, EV_KEY, false); ATTR_SHOW_FN(switches, EV_SW, false); ATTR_SHOW_FN(disabled_keys, EV_KEY, true); ATTR_SHOW_FN(disabled_switches, EV_SW, true); /* * ATTRIBUTES: * * /sys/devices/platform/gpio-keys/keys [ro] * /sys/devices/platform/gpio-keys/switches [ro] */ static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL); static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL); #define ATTR_STORE_FN(name, type) \ static ssize_t gpio_keys_store_##name(struct device *dev, \ struct device_attribute *attr, \ const char *buf, \ size_t count) \ { \ struct platform_device *pdev = to_platform_device(dev); \ struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \ ssize_t error; \ \ error = gpio_keys_attr_store_helper(ddata, buf, type); \ if (error) \ return error; \ \ return count; \ } ATTR_STORE_FN(disabled_keys, EV_KEY); ATTR_STORE_FN(disabled_switches, EV_SW); /* * ATTRIBUTES: * * /sys/devices/platform/gpio-keys/disabled_keys [rw] * /sys/devices/platform/gpio-keys/disables_switches [rw] */ static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO, gpio_keys_show_disabled_keys, gpio_keys_store_disabled_keys); static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO, gpio_keys_show_disabled_switches, gpio_keys_store_disabled_switches); static struct attribute *gpio_keys_attrs[] = { &dev_attr_keys.attr, &dev_attr_switches.attr, &dev_attr_disabled_keys.attr, &dev_attr_disabled_switches.attr, NULL, }; static struct attribute_group gpio_keys_attr_group = { .attrs = gpio_keys_attrs, };
static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata) { const struct gpio_keys_button *button = bdata->button; struct input_dev *input = bdata->input; unsigned int type = button->type ?: EV_KEY; int state; state = gpiod_get_value_cansleep(bdata->gpiod); if (state < 0) { dev_err(input->dev.parent, "failed to get gpio state: %d\n", state); return; } if (type == EV_ABS) { if (state) input_event(input, type, button->code, button->value); } else { input_event(input, type, *bdata->code, state); } input_sync(input); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Baryshkov4536.29%110.00%
Alexander Stein3024.19%110.00%
Björn Andersson1915.32%110.00%
Uwe Kleine-König108.06%110.00%
Geert Uytterhoeven108.06%110.00%
Jani Nikula43.23%110.00%
Daniel Mack21.61%110.00%
Hans de Goede21.61%110.00%
Laxman Dewangan10.81%110.00%
Dmitry Torokhov10.81%110.00%
Total124100.00%10100.00%


static void gpio_keys_gpio_work_func(struct work_struct *work) { struct gpio_button_data *bdata = container_of(work, struct gpio_button_data, work.work); gpio_keys_gpio_report_event(bdata); if (bdata->button->wakeup) pm_relax(bdata->input->dev.parent); }

Contributors

PersonTokensPropCommitsCommitProp
Daniel Mack2955.77%125.00%
Neil Brown1936.54%125.00%
Dmitry Torokhov23.85%125.00%
Laxman Dewangan23.85%125.00%
Total52100.00%4100.00%


static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id) { struct gpio_button_data *bdata = dev_id; BUG_ON(irq != bdata->irq); if (bdata->button->wakeup) pm_stay_awake(bdata->input->dev.parent); mod_delayed_work(system_wq, &bdata->work, msecs_to_jiffies(bdata->software_debounce)); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
Laxman Dewangan4667.65%125.00%
Neil Brown1522.06%125.00%
Dmitry Torokhov57.35%125.00%
Phil Blundell22.94%125.00%
Total68100.00%4100.00%


static void gpio_keys_irq_timer(unsigned long _data) { struct gpio_button_data *bdata = (struct gpio_button_data *)_data; struct input_dev *input = bdata->input; unsigned long flags; spin_lock_irqsave(&bdata->lock, flags); if (bdata->key_pressed) { input_event(input, EV_KEY, *bdata->code, 0); input_sync(input); bdata->key_pressed = false; } spin_unlock_irqrestore(&bdata->lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
Laxman Dewangan8798.86%150.00%
Hans de Goede11.14%150.00%
Total88100.00%2100.00%


static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) { struct gpio_button_data *bdata = dev_id; struct input_dev *input = bdata->input; unsigned long flags; BUG_ON(irq != bdata->irq); spin_lock_irqsave(&bdata->lock, flags); if (!bdata->key_pressed) { if (bdata->button->wakeup) pm_wakeup_event(bdata->input->dev.parent, 0); input_event(input, EV_KEY, *bdata->code, 1); input_sync(input); if (!bdata->release_delay) { input_event(input, EV_KEY, *bdata->code, 0); input_sync(input); goto out; } bdata->key_pressed = true; } if (bdata->release_delay) mod_timer(&bdata->release_timer, jiffies + msecs_to_jiffies(bdata->release_delay)); out: spin_unlock_irqrestore(&bdata->lock, flags); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
Laxman Dewangan9252.27%19.09%
Phil Blundell2413.64%19.09%
Neil Brown2111.93%19.09%
Jani Nikula147.95%218.18%
Uwe Kleine-König73.98%19.09%
Dmitry Baryshkov52.84%19.09%
Dmitry Torokhov42.27%19.09%
Hans de Goede42.27%19.09%
David Brownell31.70%19.09%
Grazvydas Ignotas21.14%19.09%
Total176100.00%11100.00%


static void gpio_keys_quiesce_key(void *data) { struct gpio_button_data *bdata = data; if (bdata->gpiod) cancel_delayed_work_sync(&bdata->work); else del_timer_sync(&bdata->release_timer); }

Contributors

PersonTokensPropCommitsCommitProp
Alexander Shiyan3485.00%133.33%
Dmitry Torokhov512.50%133.33%
Geert Uytterhoeven12.50%133.33%
Total40100.00%3100.00%


static int gpio_keys_setup_key(struct platform_device *pdev, struct input_dev *input, struct gpio_keys_drvdata *ddata, const struct gpio_keys_button *button, int idx, struct fwnode_handle *child) { const char *desc = button->desc ? button->desc : "gpio_keys"; struct device *dev = &pdev->dev; struct gpio_button_data *bdata = &ddata->data[idx]; irq_handler_t isr; unsigned long irqflags; int irq; int error; bdata->input = input; bdata->button = button; spin_lock_init(&bdata->lock); if (child) { bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child, GPIOD_IN, desc); if (IS_ERR(bdata->gpiod)) { error = PTR_ERR(bdata->gpiod); if (error == -ENOENT) { /* * GPIO is optional, we may be dealing with * purely interrupt-driven setup. */ bdata->gpiod = NULL; } else { if (error != -EPROBE_DEFER) dev_err(dev, "failed to get gpio: %d\n", error); return error; } } } else if (gpio_is_valid(button->gpio)) { /* * Legacy GPIO number, so request the GPIO here and * convert it to descriptor. */ unsigned flags = GPIOF_IN; if (button->active_low) flags |= GPIOF_ACTIVE_LOW; error = devm_gpio_request_one(dev, button->gpio, flags, desc); if (error < 0) { dev_err(dev, "Failed to request GPIO %d, error %d\n", button->gpio, error); return error; } bdata->gpiod = gpio_to_desc(button->gpio); if (!bdata->gpiod) return -EINVAL; } if (bdata->gpiod) { if (button->debounce_interval) { error = gpiod_set_debounce(bdata->gpiod, button->debounce_interval * 1000); /* use timer if gpiolib doesn't provide debounce */ if (error < 0) bdata->software_debounce = button->debounce_interval; } if (button->irq) { bdata->irq = button->irq; } else { irq = gpiod_to_irq(bdata->gpiod); if (irq < 0) { error = irq; dev_err(dev, "Unable to get irq number for GPIO %d, error %d\n", button->gpio, error); return error; } bdata->irq = irq; } INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func); isr = gpio_keys_gpio_isr; irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING; } else { if (!button->irq) { dev_err(dev, "Found button without gpio or irq\n"); return -EINVAL; } bdata->irq = button->irq; if (button->type && button->type != EV_KEY) { dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n"); return -EINVAL; } bdata->release_delay = button->debounce_interval; setup_timer(&bdata->release_timer, gpio_keys_irq_timer, (unsigned long)bdata); isr = gpio_keys_irq_isr; irqflags = 0; } bdata->code = &ddata->keymap[idx]; *bdata->code = button->code; input_set_capability(input, button->type ?: EV_KEY, *bdata->code); /* * Install custom action to cancel release timer and * workqueue item. */ error = devm_add_action(dev, gpio_keys_quiesce_key, bdata); if (error) { dev_err(dev, "failed to register quiesce action, error: %d\n", error); return error; } /* * If platform has specified that the button can be disabled, * we don't want it to share the interrupt line. */ if (!button->can_disable) irqflags |= IRQF_SHARED; error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags, desc, bdata); if (error < 0) { dev_err(dev, "Unable to claim irq %d; error %d\n", bdata->irq, error); return error; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Laxman Dewangan18029.13%15.88%
Dmitry Torokhov13521.84%529.41%
Ben Dooks12119.58%15.88%
Geert Uytterhoeven447.12%15.88%
Alexander Shiyan436.96%15.88%
Hans de Goede416.63%15.88%
Mika Westerberg294.69%15.88%
Grazvydas Ignotas172.75%15.88%
Alexander Stein30.49%211.76%
Andy Shevchenko20.32%15.88%
Philippe Langlais20.32%15.88%
Boris Brezillon10.16%15.88%
Total618100.00%17100.00%


static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata) { struct input_dev *input = ddata->input; int i; for (i = 0; i < ddata->pdata->nbuttons; i++) { struct gpio_button_data *bdata = &ddata->data[i]; if (bdata->gpiod) gpio_keys_gpio_report_event(bdata); } input_sync(input); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov7098.59%150.00%
Geert Uytterhoeven11.41%150.00%
Total71100.00%2100.00%


static int gpio_keys_open(struct input_dev *input) { struct gpio_keys_drvdata *ddata = input_get_drvdata(input); const struct gpio_keys_platform_data *pdata = ddata->pdata; int error; if (pdata->enable) { error = pdata->enable(input->dev.parent); if (error) return error; } /* Report current state of buttons that are connected to GPIOs */ gpio_keys_report_state(ddata); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Shubhrajyoti Datta3549.30%133.33%
Dmitry Torokhov2535.21%133.33%
Alexandre Pereira da Silva1115.49%133.33%
Total71100.00%3100.00%


static void gpio_keys_close(struct input_dev *input) { struct gpio_keys_drvdata *ddata = input_get_drvdata(input); const struct gpio_keys_platform_data *pdata = ddata->pdata; if (pdata->disable) pdata->disable(input->dev.parent); }

Contributors

PersonTokensPropCommitsCommitProp
Shubhrajyoti Datta3675.00%150.00%
Alexandre Pereira da Silva1225.00%150.00%
Total48100.00%2100.00%

/* * Handlers for alternative sources of platform_data */ /* * Translate properties into platform_data */
static struct gpio_keys_platform_data * gpio_keys_get_devtree_pdata(struct device *dev) { struct gpio_keys_platform_data *pdata; struct gpio_keys_button *button; struct fwnode_handle *child; int nbuttons; nbuttons = device_get_child_node_count(dev); if (nbuttons == 0) return ERR_PTR(-ENODEV); pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button), GFP_KERNEL); if (!pdata) return ERR_PTR(-ENOMEM); button = (struct gpio_keys_button *)(pdata + 1); pdata->buttons = button; pdata->nbuttons = nbuttons; pdata->rep = device_property_read_bool(dev, "autorepeat"); device_property_read_string(dev, "label", &pdata->name); device_for_each_child_node(dev, child) { if (is_of_node(child)) button->irq = irq_of_parse_and_map(to_of_node(child), 0); if (fwnode_property_read_u32(child, "linux,code", &button->code)) { dev_err(dev, "Button without keycode\n"); fwnode_handle_put(child); return ERR_PTR(-EINVAL); } fwnode_property_read_string(child, "label", &button->desc); if (fwnode_property_read_u32(child, "linux,input-type", &button->type)) button->type = EV_KEY; button->wakeup = fwnode_property_read_bool(child, "wakeup-source") || /* legacy name */ fwnode_property_read_bool(child, "gpio-key,wakeup"); button->can_disable = fwnode_property_read_bool(child, "linux,can-disable"); if (fwnode_property_read_u32(child, "debounce-interval", &button->debounce_interval)) button->debounce_interval = 5; button++; } return pdata; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov8529.72%637.50%
David Jander7526.22%16.25%
Alexandre Pereira da Silva6221.68%16.25%
Andy Shevchenko248.39%16.25%
Tobias Klauser144.90%212.50%
Laxman Dewangan103.50%16.25%
Phil Blundell72.45%16.25%
Shubhrajyoti Datta51.75%16.25%
Mika Westerberg20.70%16.25%
Ben Dooks20.70%16.25%
Total286100.00%16100.00%

static const struct of_device_id gpio_keys_of_match[] = { { .compatible = "gpio-keys", }, { }, }; MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
static int gpio_keys_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev); struct fwnode_handle *child = NULL; struct gpio_keys_drvdata *ddata; struct input_dev *input; size_t size; int i, error; int wakeup = 0; if (!pdata) { pdata = gpio_keys_get_devtree_pdata(dev); if (IS_ERR(pdata)) return PTR_ERR(pdata); } size = sizeof(struct gpio_keys_drvdata) + pdata->nbuttons * sizeof(struct gpio_button_data); ddata = devm_kzalloc(dev, size, GFP_KERNEL); if (!ddata) { dev_err(dev, "failed to allocate state\n"); return -ENOMEM; } ddata->keymap = devm_kcalloc(dev, pdata->nbuttons, sizeof(ddata->keymap[0]), GFP_KERNEL); if (!ddata->keymap) return -ENOMEM; input = devm_input_allocate_device(dev); if (!input) { dev_err(dev, "failed to allocate input device\n"); return -ENOMEM; } ddata->pdata = pdata; ddata->input = input; mutex_init(&ddata->disable_lock); platform_set_drvdata(pdev, ddata); input_set_drvdata(input, ddata); input->name = pdata->name ? : pdev->name; input->phys = "gpio-keys/input0";