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