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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Internal GPIO functions.4 *5 * Copyright (C) 2013, Intel Corporation6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>7 */8 9#ifndef GPIOLIB_H10#define GPIOLIB_H11 12#include <linux/cdev.h>13#include <linux/device.h>14#include <linux/err.h>15#include <linux/gpio/consumer.h> /* for enum gpiod_flags */16#include <linux/gpio/driver.h>17#include <linux/module.h>18#include <linux/notifier.h>19#include <linux/srcu.h>20 21#define GPIOCHIP_NAME "gpiochip"22 23/**24 * struct gpio_device - internal state container for GPIO devices25 * @dev: the GPIO device struct26 * @chrdev: character device for the GPIO device27 * @id: numerical ID number for the GPIO chip28 * @mockdev: class device used by the deprecated sysfs interface (may be29 * NULL)30 * @owner: helps prevent removal of modules exporting active GPIOs31 * @chip: pointer to the corresponding gpiochip, holding static32 * data for this device33 * @descs: array of ngpio descriptors.34 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users35 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size36 * of the @descs array.37 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep38 * implying that they cannot be used from atomic context39 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned40 * at device creation time.41 * @label: a descriptive name for the GPIO device, such as the part number42 * or name of the IP component in a System on Chip.43 * @data: per-instance data assigned by the driver44 * @list: links gpio_device:s together for traversal45 * @line_state_notifier: used to notify subscribers about lines being46 * requested, released or reconfigured47 * @device_notifier: used to notify character device wait queues about the GPIO48 * device being unregistered49 * @srcu: protects the pointer to the underlying GPIO chip50 * @pin_ranges: range of pins served by the GPIO driver51 *52 * This state container holds most of the runtime variable data53 * for a GPIO device and can hold references and live on after the54 * GPIO chip has been removed, if it is still being used from55 * userspace.56 */57struct gpio_device {58 struct device dev;59 struct cdev chrdev;60 int id;61 struct device *mockdev;62 struct module *owner;63 struct gpio_chip __rcu *chip;64 struct gpio_desc *descs;65 struct srcu_struct desc_srcu;66 unsigned int base;67 u16 ngpio;68 bool can_sleep;69 const char *label;70 void *data;71 struct list_head list;72 struct blocking_notifier_head line_state_notifier;73 struct blocking_notifier_head device_notifier;74 struct srcu_struct srcu;75 76#ifdef CONFIG_PINCTRL77 /*78 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally79 * describe the actual pin range which they serve in an SoC. This80 * information would be used by pinctrl subsystem to configure81 * corresponding pins for gpio usage.82 */83 struct list_head pin_ranges;84#endif85};86 87static inline struct gpio_device *to_gpio_device(struct device *dev)88{89 return container_of(dev, struct gpio_device, dev);90}91 92/* GPIO suffixes used for ACPI and device tree lookup */93extern const char *const gpio_suffixes[];94 95#define for_each_gpio_property_name(propname, con_id) \96 for (const char * const *__suffixes = gpio_suffixes; \97 *__suffixes && ({ \98 const char *__gs = *__suffixes; \99 \100 if (con_id) \101 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \102 else \103 snprintf(propname, sizeof(propname), "%s", __gs); \104 1; \105 }); \106 __suffixes++)107 108/**109 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes110 *111 * @desc: Array of pointers to the GPIO descriptors112 * @size: Number of elements in desc113 * @chip: Parent GPIO chip114 * @get_mask: Get mask used in fastpath115 * @set_mask: Set mask used in fastpath116 * @invert_mask: Invert mask used in fastpath117 *118 * This structure is attached to struct gpiod_descs obtained from119 * gpiod_get_array() and can be passed back to get/set array functions in order120 * to activate fast processing path if applicable.121 */122struct gpio_array {123 struct gpio_desc **desc;124 unsigned int size;125 struct gpio_chip *chip;126 unsigned long *get_mask;127 unsigned long *set_mask;128 unsigned long invert_mask[];129};130 131#define for_each_gpio_desc(gc, desc) \132 for (unsigned int __i = 0; \133 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \134 __i++) \135 136#define for_each_gpio_desc_with_flag(gc, desc, flag) \137 for_each_gpio_desc(gc, desc) \138 if (!test_bit(flag, &desc->flags)) {} else139 140int gpiod_get_array_value_complex(bool raw, bool can_sleep,141 unsigned int array_size,142 struct gpio_desc **desc_array,143 struct gpio_array *array_info,144 unsigned long *value_bitmap);145int gpiod_set_array_value_complex(bool raw, bool can_sleep,146 unsigned int array_size,147 struct gpio_desc **desc_array,148 struct gpio_array *array_info,149 unsigned long *value_bitmap);150 151int gpiod_set_transitory(struct gpio_desc *desc, bool transitory);152 153void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);154 155struct gpio_desc_label {156 struct rcu_head rh;157 char str[];158};159 160/**161 * struct gpio_desc - Opaque descriptor for a GPIO162 *163 * @gdev: Pointer to the parent GPIO device164 * @flags: Binary descriptor flags165 * @label: Name of the consumer166 * @name: Line name167 * @hog: Pointer to the device node that hogs this line (if any)168 *169 * These are obtained using gpiod_get() and are preferable to the old170 * integer-based handles.171 *172 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be173 * valid until the GPIO is released.174 */175struct gpio_desc {176 struct gpio_device *gdev;177 unsigned long flags;178/* flag symbols are bit numbers */179#define FLAG_REQUESTED 0180#define FLAG_IS_OUT 1181#define FLAG_EXPORT 2 /* protected by sysfs_lock */182#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */183#define FLAG_ACTIVE_LOW 6 /* value has active low */184#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */185#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */186#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */187#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */188#define FLAG_IS_HOGGED 11 /* GPIO is hogged */189#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */190#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */191#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */192#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */193#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */194#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */195#define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */196#define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */197 198 /* Connection label */199 struct gpio_desc_label __rcu *label;200 /* Name of the GPIO */201 const char *name;202#ifdef CONFIG_OF_DYNAMIC203 struct device_node *hog;204#endif205};206 207#define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)208 209struct gpio_chip_guard {210 struct gpio_device *gdev;211 struct gpio_chip *gc;212 int idx;213};214 215DEFINE_CLASS(gpio_chip_guard,216 struct gpio_chip_guard,217 srcu_read_unlock(&_T.gdev->srcu, _T.idx),218 ({219 struct gpio_chip_guard _guard;220 221 _guard.gdev = desc->gdev;222 _guard.idx = srcu_read_lock(&_guard.gdev->srcu);223 _guard.gc = srcu_dereference(_guard.gdev->chip,224 &_guard.gdev->srcu);225 226 _guard;227 }),228 struct gpio_desc *desc)229 230int gpiod_request(struct gpio_desc *desc, const char *label);231void gpiod_free(struct gpio_desc *desc);232 233static inline int gpiod_request_user(struct gpio_desc *desc, const char *label)234{235 int ret;236 237 ret = gpiod_request(desc, label);238 if (ret == -EPROBE_DEFER)239 ret = -ENODEV;240 241 return ret;242}243 244struct gpio_desc *gpiod_find_and_request(struct device *consumer,245 struct fwnode_handle *fwnode,246 const char *con_id,247 unsigned int idx,248 enum gpiod_flags flags,249 const char *label,250 bool platform_lookup_allowed);251 252int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,253 unsigned long lflags, enum gpiod_flags dflags);254int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);255int gpiod_hog(struct gpio_desc *desc, const char *name,256 unsigned long lflags, enum gpiod_flags dflags);257int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev);258struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum);259const char *gpiod_get_label(struct gpio_desc *desc);260 261/*262 * Return the GPIO number of the passed descriptor relative to its chip263 */264static inline int gpio_chip_hwgpio(const struct gpio_desc *desc)265{266 return desc - &desc->gdev->descs[0];267}268 269/* With descriptor prefix */270 271#define gpiod_err(desc, fmt, ...) \272do { \273 scoped_guard(srcu, &desc->gdev->desc_srcu) { \274 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \275 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \276 } \277} while (0)278 279#define gpiod_warn(desc, fmt, ...) \280do { \281 scoped_guard(srcu, &desc->gdev->desc_srcu) { \282 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \283 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \284 } \285} while (0)286 287#define gpiod_dbg(desc, fmt, ...) \288do { \289 scoped_guard(srcu, &desc->gdev->desc_srcu) { \290 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \291 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \292 } \293} while (0)294 295/* With chip prefix */296 297#define chip_err(gc, fmt, ...) \298 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)299#define chip_warn(gc, fmt, ...) \300 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)301#define chip_info(gc, fmt, ...) \302 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)303#define chip_dbg(gc, fmt, ...) \304 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__)305 306#endif /* GPIOLIB_H */307