// SPDX-License-Identifier: GPL-2.0-only /* * Driver for keys on GPIO lines capable of generating interrupts. * * Copyright 2005 Phil Blundell * Copyright 2010, 2011 David Jander <[email protected]> */ #include <linux/module.h> #include <linux/hrtimer.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> #include <dt-bindings/input/gpio-keys.h> struct gpio_button_data { … }; struct gpio_keys_drvdata { … }; /* * 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) { … } /** * get_bm_events_by_type() - returns bitmap of supported events per @type * @dev: 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) { … } static void gpio_keys_quiesce_key(void *data) { … } /** * 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) { … } /** * 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) { … } /** * 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) { … } /** * 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) { … } #define ATTR_SHOW_FN(name, 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) … 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[] = …; ATTRIBUTE_GROUPS(…); static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata) { … } static void gpio_keys_debounce_event(struct gpio_button_data *bdata) { … } static void gpio_keys_gpio_work_func(struct work_struct *work) { … } static enum hrtimer_restart gpio_keys_debounce_timer(struct hrtimer *t) { … } static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id) { … } static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t) { … } static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id) { … } 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) { … } static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata) { … } static int gpio_keys_open(struct input_dev *input) { … } static void gpio_keys_close(struct input_dev *input) { … } /* * 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) { … } static const struct of_device_id gpio_keys_of_match[] = …; MODULE_DEVICE_TABLE(of, gpio_keys_of_match); static int gpio_keys_probe(struct platform_device *pdev) { … } static int __maybe_unused gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata) { … } static void __maybe_unused gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata) { … } static int __maybe_unused gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata) { … } static void __maybe_unused gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata) { … } static int gpio_keys_suspend(struct device *dev) { … } static int gpio_keys_resume(struct device *dev) { … } static DEFINE_SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume); static void gpio_keys_shutdown(struct platform_device *pdev) { … } static struct platform_driver gpio_keys_device_driver = …; static int __init gpio_keys_init(void) { … } static void __exit gpio_keys_exit(void) { … } late_initcall(gpio_keys_init); module_exit(gpio_keys_exit); MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_ALIAS(…) …;
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