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/srcu.h> 20 #include <linux/workqueue.h> 21 22 #define GPIOCHIP_NAME "gpiochip" 23 24 /** 25 * struct gpio_device - internal state container for GPIO devices 26 * @dev: the GPIO device struct 27 * @chrdev: character device for the GPIO device 28 * @id: numerical ID number for the GPIO chip 29 * @mockdev: class device used by the deprecated sysfs interface (may be 30 * NULL) 31 * @owner: helps prevent removal of modules exporting active GPIOs 32 * @chip: pointer to the corresponding gpiochip, holding static 33 * data for this device 34 * @descs: array of ngpio descriptors. 35 * @desc_srcu: ensures consistent state of GPIO descriptors exposed to users 36 * @ngpio: the number of GPIO lines on this GPIO device, equal to the size 37 * of the @descs array. 38 * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep 39 * implying that they cannot be used from atomic context 40 * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned 41 * at device creation time. 42 * @label: a descriptive name for the GPIO device, such as the part number 43 * or name of the IP component in a System on Chip. 44 * @data: per-instance data assigned by the driver 45 * @list: links gpio_device:s together for traversal 46 * @line_state_notifier: used to notify subscribers about lines being 47 * requested, released or reconfigured 48 * @line_state_wq: used to emit line state events from a separate thread in 49 * process context 50 * @device_notifier: used to notify character device wait queues about the GPIO 51 * device being unregistered 52 * @srcu: protects the pointer to the underlying GPIO chip 53 * @pin_ranges: range of pins served by the GPIO driver 54 * 55 * This state container holds most of the runtime variable data 56 * for a GPIO device and can hold references and live on after the 57 * GPIO chip has been removed, if it is still being used from 58 * userspace. 59 */ 60 struct gpio_device { 61 struct device dev; 62 struct cdev chrdev; 63 int id; 64 struct device *mockdev; 65 struct module *owner; 66 struct gpio_chip __rcu *chip; 67 struct gpio_desc *descs; 68 struct srcu_struct desc_srcu; 69 unsigned int base; 70 u16 ngpio; 71 bool can_sleep; 72 const char *label; 73 void *data; 74 struct list_head list; 75 struct atomic_notifier_head line_state_notifier; 76 struct workqueue_struct *line_state_wq; 77 struct blocking_notifier_head device_notifier; 78 struct srcu_struct srcu; 79 80 #ifdef CONFIG_PINCTRL 81 /* 82 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 83 * describe the actual pin range which they serve in an SoC. This 84 * information would be used by pinctrl subsystem to configure 85 * corresponding pins for gpio usage. 86 */ 87 struct list_head pin_ranges; 88 #endif 89 }; 90 91 static inline struct gpio_device *to_gpio_device(struct device *dev) 92 { 93 return container_of(dev, struct gpio_device, dev); 94 } 95 96 /* GPIO suffixes used for ACPI and device tree lookup */ 97 extern const char *const gpio_suffixes[]; 98 99 #define for_each_gpio_property_name(propname, con_id) \ 100 for (const char * const *__suffixes = gpio_suffixes; \ 101 *__suffixes && ({ \ 102 const char *__gs = *__suffixes; \ 103 \ 104 if (con_id) \ 105 snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs); \ 106 else \ 107 snprintf(propname, sizeof(propname), "%s", __gs); \ 108 1; \ 109 }); \ 110 __suffixes++) 111 112 /** 113 * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes 114 * 115 * @desc: Array of pointers to the GPIO descriptors 116 * @size: Number of elements in desc 117 * @chip: Parent GPIO chip 118 * @get_mask: Get mask used in fastpath 119 * @set_mask: Set mask used in fastpath 120 * @invert_mask: Invert mask used in fastpath 121 * 122 * This structure is attached to struct gpiod_descs obtained from 123 * gpiod_get_array() and can be passed back to get/set array functions in order 124 * to activate fast processing path if applicable. 125 */ 126 struct gpio_array { 127 struct gpio_desc **desc; 128 unsigned int size; 129 struct gpio_chip *chip; 130 unsigned long *get_mask; 131 unsigned long *set_mask; 132 unsigned long invert_mask[]; 133 }; 134 135 #define for_each_gpio_desc(gc, desc) \ 136 for (unsigned int __i = 0; \ 137 __i < gc->ngpio && (desc = gpiochip_get_desc(gc, __i)); \ 138 __i++) \ 139 140 #define for_each_gpio_desc_with_flag(gc, desc, flag) \ 141 for_each_gpio_desc(gc, desc) \ 142 if (!test_bit(flag, &desc->flags)) {} else 143 144 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 145 unsigned int array_size, 146 struct gpio_desc **desc_array, 147 struct gpio_array *array_info, 148 unsigned long *value_bitmap); 149 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 150 unsigned int array_size, 151 struct gpio_desc **desc_array, 152 struct gpio_array *array_info, 153 unsigned long *value_bitmap); 154 155 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); 156 157 void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action); 158 int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value); 159 int gpiod_direction_input_nonotify(struct gpio_desc *desc); 160 161 struct gpio_desc_label { 162 struct rcu_head rh; 163 char str[]; 164 }; 165 166 /** 167 * struct gpio_desc - Opaque descriptor for a GPIO 168 * 169 * @gdev: Pointer to the parent GPIO device 170 * @flags: Binary descriptor flags 171 * @label: Name of the consumer 172 * @name: Line name 173 * @hog: Pointer to the device node that hogs this line (if any) 174 * @debounce_period_us: Debounce period in microseconds 175 * 176 * These are obtained using gpiod_get() and are preferable to the old 177 * integer-based handles. 178 * 179 * Contrary to integers, a pointer to a &struct gpio_desc is guaranteed to be 180 * valid until the GPIO is released. 181 */ 182 struct gpio_desc { 183 struct gpio_device *gdev; 184 unsigned long flags; 185 /* flag symbols are bit numbers */ 186 #define FLAG_REQUESTED 0 187 #define FLAG_IS_OUT 1 188 #define FLAG_EXPORT 2 /* protected by sysfs_lock */ 189 #define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */ 190 #define FLAG_ACTIVE_LOW 6 /* value has active low */ 191 #define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */ 192 #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ 193 #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ 194 #define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */ 195 #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ 196 #define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ 197 #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ 198 #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ 199 #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ 200 #define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ 201 #define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ 202 #define FLAG_EVENT_CLOCK_REALTIME 18 /* GPIO CDEV reports REALTIME timestamps in events */ 203 #define FLAG_EVENT_CLOCK_HTE 19 /* GPIO CDEV reports hardware timestamps in events */ 204 205 /* Connection label */ 206 struct gpio_desc_label __rcu *label; 207 /* Name of the GPIO */ 208 const char *name; 209 #ifdef CONFIG_OF_DYNAMIC 210 struct device_node *hog; 211 #endif 212 #ifdef CONFIG_GPIO_CDEV 213 /* debounce period in microseconds */ 214 unsigned int debounce_period_us; 215 #endif 216 }; 217 218 #define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) 219 220 struct gpio_chip_guard { 221 struct gpio_device *gdev; 222 struct gpio_chip *gc; 223 int idx; 224 }; 225 226 DEFINE_CLASS(gpio_chip_guard, 227 struct gpio_chip_guard, 228 srcu_read_unlock(&_T.gdev->srcu, _T.idx), 229 ({ 230 struct gpio_chip_guard _guard; 231 232 _guard.gdev = desc->gdev; 233 _guard.idx = srcu_read_lock(&_guard.gdev->srcu); 234 _guard.gc = srcu_dereference(_guard.gdev->chip, 235 &_guard.gdev->srcu); 236 237 _guard; 238 }), 239 struct gpio_desc *desc) 240 241 int gpiod_request(struct gpio_desc *desc, const char *label); 242 void gpiod_free(struct gpio_desc *desc); 243 244 static inline int gpiod_request_user(struct gpio_desc *desc, const char *label) 245 { 246 int ret; 247 248 ret = gpiod_request(desc, label); 249 if (ret == -EPROBE_DEFER) 250 ret = -ENODEV; 251 252 return ret; 253 } 254 255 struct gpio_desc *gpiod_find_and_request(struct device *consumer, 256 struct fwnode_handle *fwnode, 257 const char *con_id, 258 unsigned int idx, 259 enum gpiod_flags flags, 260 const char *label, 261 bool platform_lookup_allowed); 262 263 int gpio_do_set_config(struct gpio_desc *desc, unsigned long config); 264 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 265 unsigned long lflags, enum gpiod_flags dflags); 266 int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce); 267 int gpiod_hog(struct gpio_desc *desc, const char *name, 268 unsigned long lflags, enum gpiod_flags dflags); 269 int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev); 270 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum); 271 const char *gpiod_get_label(struct gpio_desc *desc); 272 273 /* 274 * Return the GPIO number of the passed descriptor relative to its chip 275 */ 276 static inline int gpio_chip_hwgpio(const struct gpio_desc *desc) 277 { 278 return desc - &desc->gdev->descs[0]; 279 } 280 281 /* With descriptor prefix */ 282 283 #define gpiod_err(desc, fmt, ...) \ 284 do { \ 285 scoped_guard(srcu, &desc->gdev->desc_srcu) { \ 286 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ 287 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ 288 } \ 289 } while (0) 290 291 #define gpiod_warn(desc, fmt, ...) \ 292 do { \ 293 scoped_guard(srcu, &desc->gdev->desc_srcu) { \ 294 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ 295 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ 296 } \ 297 } while (0) 298 299 #define gpiod_dbg(desc, fmt, ...) \ 300 do { \ 301 scoped_guard(srcu, &desc->gdev->desc_srcu) { \ 302 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), \ 303 gpiod_get_label(desc) ? : "?", ##__VA_ARGS__); \ 304 } \ 305 } while (0) 306 307 /* With chip prefix */ 308 309 #define chip_err(gc, fmt, ...) \ 310 dev_err(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 311 #define chip_warn(gc, fmt, ...) \ 312 dev_warn(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 313 #define chip_info(gc, fmt, ...) \ 314 dev_info(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 315 #define chip_dbg(gc, fmt, ...) \ 316 dev_dbg(&gc->gpiodev->dev, "(%s): " fmt, gc->label, ##__VA_ARGS__) 317 318 #endif /* GPIOLIB_H */ 319