1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Internal GPIO functions. 4 * 5 * Copyright (C) 2013, Intel Corporation 6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com> 7 */ 8 9 #ifndef GPIOLIB_H 10 #define GPIOLIB_H 11 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/spinlock.h> 20 #include <linux/string.h> 21 #include <linux/srcu.h> 22 #include <linux/workqueue.h> 23 24 #define GPIOCHIP_NAME "gpiochip" 25 26 struct fwnode_handle; 27 28 /** 29 * struct gpio_device - internal state container for GPIO devices 30 * @dev: the GPIO device struct 31 * @chrdev: character device for the GPIO device 32 * @id: numerical ID number for the GPIO chip 33 * @owner: helps prevent removal of modules exporting active GPIOs 34 * @chip: pointer to the corresponding gpiochip, holding static 35 * data for this device 36 * @descs: array of ngpio descriptors. 37 * @valid_mask: If not %NULL, holds bitmask of GPIOs which are valid to be 38 * used from the chip. 39 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users 40 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size 41 * of the @descs array. 42 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep 43 * implying that they cannot be used from atomic context 44 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned 45 * at device creation time. 46 * @label: a descriptive name for the GPIO device, such as the part number 47 * or name of the IP component in a System on Chip. 48 * @data: per-instance data assigned by the driver 49 * @list: links gpio_device:s together for traversal 50 * @line_state_notifier: used to notify subscribers about lines being 51 * requested, released or reconfigured 52 * @line_state_lock: RW-spinlock protecting the line state notifier 53 * @line_state_wq: used to emit line state events from a separate thread in 54 * process context 55 * @device_notifier: used to notify character device wait queues about the GPIO 56 * device being unregistered 57 * @srcu: protects the pointer to the underlying GPIO chip 58 * @pin_ranges: range of pins served by the GPIO driver 59 * 60 * This state container holds most of the runtime variable data 61 * for a GPIO device and can hold references and live on after the 62 * GPIO chip has been removed, if it is still being used from 63 * userspace. 64 */ 65 struct gpio_device { 66 struct device dev; 67 struct cdev chrdev; 68 int id; 69 struct module *owner; 70 struct gpio_chip __rcu *chip; 71 struct gpio_desc *descs; 72 unsigned long *valid_mask; 73 struct srcu_struct desc_srcu; 74 unsigned int base; 75 u16 ngpio; 76 bool can_sleep; 77 const char *label; 78 void *data; 79 struct list_head list; 80 struct raw_notifier_head line_state_notifier; 81 rwlock_t line_state_lock; 82 struct workqueue_struct *line_state_wq; 83 struct blocking_notifier_head device_notifier; 84 struct srcu_struct srcu; 85 86 #ifdef CONFIG_PINCTRL 87 /* 88 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 89 * describe the actual pin range which they serve in an SoC. This 90 * information would be used by pinctrl subsystem to configure 91 * corresponding pins for gpio usage. 92 */ 93 struct list_head pin_ranges; 94 #endif 95 }; 96 97 static inline struct gpio_device *to_gpio_device(struct device *dev) 98 { 99 return container_of(dev, struct gpio_device, dev); 100 } 101 102 /* GPIO suffixes used for ACPI and device tree lookup */ 103 extern const char *const gpio_suffixes[]; 104 105 #define for_each_gpio_property_name(propname, con_id) \ 106 for (const char * const *__suffixes = gpio_suffixes; \ 107 *__suffixes && ({ \ 108 const char *__gs = *__suffixes; \ 109 \ 110 if (con_id) \ 111 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \ 112 else \ 113 strscpy(propname, __gs); \ 114 1; \ 115 }); \ 116 __suffixes++) 117 118 /** 119 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes 120 * 121 * @desc: Array of pointers to the GPIO descriptors 122 * @size: Number of elements in desc 123 * @gdev: Parent GPIO device 124 * @get_mask: Get mask used in fastpath 125 * @set_mask: Set mask used in fastpath 126 * @invert_mask: Invert mask used in fastpath 127 * 128 * This structure is attached to struct gpiod_descs obtained from 129 * gpiod_get_array() and can be passed back to get/set array functions in order 130 * to activate fast processing path if applicable. 131 */ 132 struct gpio_array { 133 struct gpio_desc **desc; 134 unsigned int size; 135 struct gpio_device *gdev; 136 unsigned long *get_mask; 137 unsigned long *set_mask; 138 unsigned long invert_mask[]; 139 }; 140 141 #define for_each_gpio_desc(gc, desc) \ 142 for (unsigned int __i = 0; \ 143 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ 144 __i++) \ 145 146 #define for_each_gpio_desc_with_flag(gc, desc, flag) \ 147 for_each_gpio_desc(gc, desc) \ 148 if (!test_bit(flag, &desc->flags)) {} else 149 150 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 151 unsigned int array_size, 152 struct gpio_desc **desc_array, 153 struct gpio_array *array_info, 154 unsigned long *value_bitmap); 155 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 156 unsigned int array_size, 157 struct gpio_desc **desc_array, 158 struct gpio_array *array_info, 159 unsigned long *value_bitmap); 160 161 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); 162 163 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); 164 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value); 165 int gpiod_direction_input_nonotify(struct gpio_desc *desc); 166 167 struct gpio_desc_label { 168 struct rcu_head rh; 169 char str[]; 170 }; 171 172 /** 173 * struct gpio_desc - Opaque descriptor for a GPIO 174 * 175 * @gdev: Pointer to the parent GPIO device 176 * @flags: Binary descriptor flags 177 * @label: Name of the consumer 178 * @name: Line name 179 * @hog: Pointer to the device node that hogs this line (if any) 180 * @debounce_period_us: Debounce period in microseconds 181 * 182 * These are obtained using gpiod_get() and are preferable to the old 183 * integer-based handles. 184 * 185 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 186 * valid until the GPIO is released. 187 */ 188 struct gpio_desc { 189 struct gpio_device *gdev; 190 unsigned long flags; 191 /* flag symbols are bit numbers */ 192 #define GPIOD_FLAG_REQUESTED 0 /* GPIO is in use */ 193 #define GPIOD_FLAG_IS_OUT 1 /* GPIO is in output mode */ 194 #define GPIOD_FLAG_EXPORT 2 /* GPIO is exported to user-space */ 195 #define GPIOD_FLAG_SYSFS 3 /* GPIO is exported via /sys/class/gpio */ 196 #define GPIOD_FLAG_ACTIVE_LOW 6 /* GPIO is active-low */ 197 #define GPIOD_FLAG_OPEN_DRAIN 7 /* GPIO is open drain type */ 198 #define GPIOD_FLAG_OPEN_SOURCE 8 /* GPIO is open source type */ 199 #define GPIOD_FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 200 #define GPIOD_FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 201 #define GPIOD_FLAG_IS_HOGGED 11 /* GPIO is hogged */ 202 #define GPIOD_FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 203 #define GPIOD_FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 204 #define GPIOD_FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 205 #define GPIOD_FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 206 #define GPIOD_FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 207 #define GPIOD_FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 208 #define GPIOD_FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 209 #define GPIOD_FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 210 #define GPIOD_FLAG_SHARED 20 /* GPIO is shared by multiple consumers */ 211 #define GPIOD_FLAG_SHARED_PROXY 21 /* GPIO is a virtual proxy to a physically shared pin. */ 212 213 /* Connection label */ 214 struct gpio_desc_label __rcu *label; 215 /* Name of the GPIO */ 216 const char *name; 217 #ifdef CONFIG_OF_DYNAMIC 218 struct device_node *hog; 219 #endif 220 #ifdef CONFIG_GPIO_CDEV 221 /* debounce period in microseconds */ 222 unsigned int debounce_period_us; 223 #endif 224 }; 225 226 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 227 228 struct gpio_chip_guard { 229 struct gpio_device *gdev; 230 struct gpio_chip *gc; 231 int idx; 232 }; 233 234 DEFINE_CLASS(gpio_chip_guard, 235 struct gpio_chip_guard, 236 srcu_read_unlock(&_T.gdev->srcu, _T.idx), 237 ({ 238 struct gpio_chip_guard _guard; 239 240 _guard.gdev = desc->gdev; 241 _guard.idx = srcu_read_lock(&_guard.gdev->srcu); 242 _guard.gc = srcu_dereference(_guard.gdev->chip, 243 &_guard.gdev->srcu); 244 245 _guard; 246 }), 247 struct gpio_desc *desc) 248 249 int gpiod_request(struct gpio_desc *desc, const char *label); 250 int gpiod_request_commit(struct gpio_desc *desc, const char *label); 251 void gpiod_free(struct gpio_desc *desc); 252 void gpiod_free_commit(struct gpio_desc *desc); 253 254 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 255 { 256 int ret; 257 258 ret = gpiod_request(desc, label); 259 if (ret == -EPROBE_DEFER) 260 ret = -ENODEV; 261 262 return ret; 263 } 264 265 struct gpio_desc *gpiod_find_and_request(struct device *consumer, 266 struct fwnode_handle *fwnode, 267 const char *con_id, 268 unsigned int idx, 269 enum gpiod_flags flags, 270 const char *label, 271 bool platform_lookup_allowed); 272 273 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config); 274 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 275 unsigned long lflags, enum gpiod_flags dflags); 276 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 277 int gpiod_hog(struct gpio_desc *desc, const char *name, 278 unsigned long lflags, enum gpiod_flags dflags); 279 int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode); 280 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); 281 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); 282 const char *gpiod_get_label(struct gpio_desc *desc); 283 284 /* With descriptor prefix */ 285 286 #define __gpiod_pr(level, desc, fmt, ...) \ 287 do { \ 288 scoped_guard(srcu, &desc->gdev->desc_srcu) { \ 289 pr_##level("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ 290 gpiod_get_label(desc) ?: "?", ##__VA_ARGS__); \ 291 } \ 292 } while (0) 293 294 #define gpiod_err(desc, fmt, ...) __gpiod_pr(err, desc, fmt, ##__VA_ARGS__) 295 #define gpiod_warn(desc, fmt, ...) __gpiod_pr(warn, desc, fmt, ##__VA_ARGS__) 296 #define gpiod_dbg(desc, fmt, ...) __gpiod_pr(debug, desc, fmt, ##__VA_ARGS__) 297 298 /* With chip prefix */ 299 300 #define __gpiochip_pr(level, gc, fmt, ...) \ 301 do { \ 302 dev_##level(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__); \ 303 } while (0) 304 305 #define gpiochip_err(gc, fmt, ...) __gpiochip_pr(err, gc, fmt, ##__VA_ARGS__) 306 #define gpiochip_warn(gc, fmt, ...) __gpiochip_pr(warn, gc, fmt, ##__VA_ARGS__) 307 #define gpiochip_info(gc, fmt, ...) __gpiochip_pr(info, gc, fmt, ##__VA_ARGS__) 308 #define gpiochip_dbg(gc, fmt, ...) __gpiochip_pr(dbg, gc, fmt, ##__VA_ARGS__) 309 310 #endif /* GPIOLIB_H */ 311