| 1 | #ifndef _ASM_GENERIC_GPIO_H |
| 2 | #define _ASM_GENERIC_GPIO_H |
| 3 | |
| 4 | #include <linux/kernel.h> |
| 5 | #include <linux/types.h> |
| 6 | #include <linux/errno.h> |
| 7 | #include <linux/of.h> |
| 8 | #include <linux/pinctrl/pinctrl.h> |
| 9 | |
| 10 | #ifdef CONFIG_GPIOLIB |
| 11 | |
| 12 | #include <linux/compiler.h> |
| 13 | |
| 14 | /* Platforms may implement their GPIO interface with library code, |
| 15 | * at a small performance cost for non-inlined operations and some |
| 16 | * extra memory (for code and for per-GPIO table entries). |
| 17 | * |
| 18 | * While the GPIO programming interface defines valid GPIO numbers |
| 19 | * to be in the range 0..MAX_INT, this library restricts them to the |
| 20 | * smaller range 0..ARCH_NR_GPIOS-1. |
| 21 | * |
| 22 | * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of |
| 23 | * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is |
| 24 | * actually an estimate of a board-specific value. |
| 25 | */ |
| 26 | |
| 27 | #ifndef ARCH_NR_GPIOS |
| 28 | #define ARCH_NR_GPIOS 256 |
| 29 | #endif |
| 30 | |
| 31 | /* |
| 32 | * "valid" GPIO numbers are nonnegative and may be passed to |
| 33 | * setup routines like gpio_request(). only some valid numbers |
| 34 | * can successfully be requested and used. |
| 35 | * |
| 36 | * Invalid GPIO numbers are useful for indicating no-such-GPIO in |
| 37 | * platform data and other tables. |
| 38 | */ |
| 39 | |
| 40 | static inline bool gpio_is_valid(int number) |
| 41 | { |
| 42 | return number >= 0 && number < ARCH_NR_GPIOS; |
| 43 | } |
| 44 | |
| 45 | struct device; |
| 46 | struct gpio; |
| 47 | struct seq_file; |
| 48 | struct module; |
| 49 | struct device_node; |
| 50 | |
| 51 | /** |
| 52 | * struct gpio_chip - abstract a GPIO controller |
| 53 | * @label: for diagnostics |
| 54 | * @dev: optional device providing the GPIOs |
| 55 | * @owner: helps prevent removal of modules exporting active GPIOs |
| 56 | * @list: links gpio_chips together for traversal |
| 57 | * @request: optional hook for chip-specific activation, such as |
| 58 | * enabling module power and clock; may sleep |
| 59 | * @free: optional hook for chip-specific deactivation, such as |
| 60 | * disabling module power and clock; may sleep |
| 61 | * @get_direction: returns direction for signal "offset", 0=out, 1=in, |
| 62 | * (same as GPIOF_DIR_XXX), or negative error |
| 63 | * @direction_input: configures signal "offset" as input, or returns error |
| 64 | * @get: returns value for signal "offset"; for output signals this |
| 65 | * returns either the value actually sensed, or zero |
| 66 | * @direction_output: configures signal "offset" as output, or returns error |
| 67 | * @set_debounce: optional hook for setting debounce time for specified gpio in |
| 68 | * interrupt triggered gpio chips |
| 69 | * @set: assigns output value for signal "offset" |
| 70 | * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; |
| 71 | * implementation may not sleep |
| 72 | * @dbg_show: optional routine to show contents in debugfs; default code |
| 73 | * will be used when this is omitted, but custom code can show extra |
| 74 | * state (such as pullup/pulldown configuration). |
| 75 | * @base: identifies the first GPIO number handled by this chip; or, if |
| 76 | * negative during registration, requests dynamic ID allocation. |
| 77 | * @ngpio: the number of GPIOs handled by this controller; the last GPIO |
| 78 | * handled is (base + ngpio - 1). |
| 79 | * @can_sleep: flag must be set iff get()/set() methods sleep, as they |
| 80 | * must while accessing GPIO expander chips over I2C or SPI |
| 81 | * @names: if set, must be an array of strings to use as alternative |
| 82 | * names for the GPIOs in this chip. Any entry in the array |
| 83 | * may be NULL if there is no alias for the GPIO, however the |
| 84 | * array must be @ngpio entries long. A name can include a single printk |
| 85 | * format specifier for an unsigned int. It is substituted by the actual |
| 86 | * number of the gpio. |
| 87 | * |
| 88 | * A gpio_chip can help platforms abstract various sources of GPIOs so |
| 89 | * they can all be accessed through a common programing interface. |
| 90 | * Example sources would be SOC controllers, FPGAs, multifunction |
| 91 | * chips, dedicated GPIO expanders, and so on. |
| 92 | * |
| 93 | * Each chip controls a number of signals, identified in method calls |
| 94 | * by "offset" values in the range 0..(@ngpio - 1). When those signals |
| 95 | * are referenced through calls like gpio_get_value(gpio), the offset |
| 96 | * is calculated by subtracting @base from the gpio number. |
| 97 | */ |
| 98 | struct gpio_chip { |
| 99 | const char *label; |
| 100 | struct device *dev; |
| 101 | struct module *owner; |
| 102 | struct list_head list; |
| 103 | |
| 104 | int (*request)(struct gpio_chip *chip, |
| 105 | unsigned offset); |
| 106 | void (*free)(struct gpio_chip *chip, |
| 107 | unsigned offset); |
| 108 | int (*get_direction)(struct gpio_chip *chip, |
| 109 | unsigned offset); |
| 110 | int (*direction_input)(struct gpio_chip *chip, |
| 111 | unsigned offset); |
| 112 | int (*get)(struct gpio_chip *chip, |
| 113 | unsigned offset); |
| 114 | int (*direction_output)(struct gpio_chip *chip, |
| 115 | unsigned offset, int value); |
| 116 | int (*set_debounce)(struct gpio_chip *chip, |
| 117 | unsigned offset, unsigned debounce); |
| 118 | |
| 119 | void (*set)(struct gpio_chip *chip, |
| 120 | unsigned offset, int value); |
| 121 | |
| 122 | int (*to_irq)(struct gpio_chip *chip, |
| 123 | unsigned offset); |
| 124 | |
| 125 | void (*dbg_show)(struct seq_file *s, |
| 126 | struct gpio_chip *chip); |
| 127 | int base; |
| 128 | u16 ngpio; |
| 129 | const char *const *names; |
| 130 | unsigned can_sleep:1; |
| 131 | unsigned exported:1; |
| 132 | |
| 133 | #if defined(CONFIG_OF_GPIO) |
| 134 | /* |
| 135 | * If CONFIG_OF is enabled, then all GPIO controllers described in the |
| 136 | * device tree automatically may have an OF translation |
| 137 | */ |
| 138 | struct device_node *of_node; |
| 139 | int of_gpio_n_cells; |
| 140 | int (*of_xlate)(struct gpio_chip *gc, |
| 141 | const struct of_phandle_args *gpiospec, u32 *flags); |
| 142 | #endif |
| 143 | #ifdef CONFIG_PINCTRL |
| 144 | /* |
| 145 | * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally |
| 146 | * describe the actual pin range which they serve in an SoC. This |
| 147 | * information would be used by pinctrl subsystem to configure |
| 148 | * corresponding pins for gpio usage. |
| 149 | */ |
| 150 | struct list_head pin_ranges; |
| 151 | #endif |
| 152 | }; |
| 153 | |
| 154 | extern const char *gpiochip_is_requested(struct gpio_chip *chip, |
| 155 | unsigned offset); |
| 156 | extern struct gpio_chip *gpio_to_chip(unsigned gpio); |
| 157 | |
| 158 | /* add/remove chips */ |
| 159 | extern int gpiochip_add(struct gpio_chip *chip); |
| 160 | extern int __must_check gpiochip_remove(struct gpio_chip *chip); |
| 161 | extern struct gpio_chip *gpiochip_find(void *data, |
| 162 | int (*match)(struct gpio_chip *chip, |
| 163 | void *data)); |
| 164 | |
| 165 | |
| 166 | /* Always use the library code for GPIO management calls, |
| 167 | * or when sleeping may be involved. |
| 168 | */ |
| 169 | extern int gpio_request(unsigned gpio, const char *label); |
| 170 | extern void gpio_free(unsigned gpio); |
| 171 | |
| 172 | extern int gpio_direction_input(unsigned gpio); |
| 173 | extern int gpio_direction_output(unsigned gpio, int value); |
| 174 | |
| 175 | extern int gpio_set_debounce(unsigned gpio, unsigned debounce); |
| 176 | |
| 177 | extern int gpio_get_value_cansleep(unsigned gpio); |
| 178 | extern void gpio_set_value_cansleep(unsigned gpio, int value); |
| 179 | |
| 180 | |
| 181 | /* A platform's <asm/gpio.h> code may want to inline the I/O calls when |
| 182 | * the GPIO is constant and refers to some always-present controller, |
| 183 | * giving direct access to chip registers and tight bitbanging loops. |
| 184 | */ |
| 185 | extern int __gpio_get_value(unsigned gpio); |
| 186 | extern void __gpio_set_value(unsigned gpio, int value); |
| 187 | |
| 188 | extern int __gpio_cansleep(unsigned gpio); |
| 189 | |
| 190 | extern int __gpio_to_irq(unsigned gpio); |
| 191 | |
| 192 | extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); |
| 193 | extern int gpio_request_array(const struct gpio *array, size_t num); |
| 194 | extern void gpio_free_array(const struct gpio *array, size_t num); |
| 195 | |
| 196 | #ifdef CONFIG_GPIO_SYSFS |
| 197 | |
| 198 | /* |
| 199 | * A sysfs interface can be exported by individual drivers if they want, |
| 200 | * but more typically is configured entirely from userspace. |
| 201 | */ |
| 202 | extern int gpio_export(unsigned gpio, bool direction_may_change); |
| 203 | extern int gpio_export_link(struct device *dev, const char *name, |
| 204 | unsigned gpio); |
| 205 | extern int gpio_sysfs_set_active_low(unsigned gpio, int value); |
| 206 | extern void gpio_unexport(unsigned gpio); |
| 207 | |
| 208 | #endif /* CONFIG_GPIO_SYSFS */ |
| 209 | |
| 210 | #ifdef CONFIG_PINCTRL |
| 211 | |
| 212 | /** |
| 213 | * struct gpio_pin_range - pin range controlled by a gpio chip |
| 214 | * @head: list for maintaining set of pin ranges, used internally |
| 215 | * @pctldev: pinctrl device which handles corresponding pins |
| 216 | * @range: actual range of pins controlled by a gpio controller |
| 217 | */ |
| 218 | |
| 219 | struct gpio_pin_range { |
| 220 | struct list_head node; |
| 221 | struct pinctrl_dev *pctldev; |
| 222 | struct pinctrl_gpio_range range; |
| 223 | }; |
| 224 | |
| 225 | int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
| 226 | unsigned int gpio_offset, unsigned int pin_offset, |
| 227 | unsigned int npins); |
| 228 | void gpiochip_remove_pin_ranges(struct gpio_chip *chip); |
| 229 | |
| 230 | #else |
| 231 | |
| 232 | static inline int |
| 233 | gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, |
| 234 | unsigned int gpio_offset, unsigned int pin_offset, |
| 235 | unsigned int npins) |
| 236 | { |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | static inline void |
| 241 | gpiochip_remove_pin_ranges(struct gpio_chip *chip) |
| 242 | { |
| 243 | } |
| 244 | |
| 245 | #endif /* CONFIG_PINCTRL */ |
| 246 | |
| 247 | #else /* !CONFIG_GPIOLIB */ |
| 248 | |
| 249 | static inline bool gpio_is_valid(int number) |
| 250 | { |
| 251 | /* only non-negative numbers are valid */ |
| 252 | return number >= 0; |
| 253 | } |
| 254 | |
| 255 | /* platforms that don't directly support access to GPIOs through I2C, SPI, |
| 256 | * or other blocking infrastructure can use these wrappers. |
| 257 | */ |
| 258 | |
| 259 | static inline int gpio_cansleep(unsigned gpio) |
| 260 | { |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | static inline int gpio_get_value_cansleep(unsigned gpio) |
| 265 | { |
| 266 | might_sleep(); |
| 267 | return __gpio_get_value(gpio); |
| 268 | } |
| 269 | |
| 270 | static inline void gpio_set_value_cansleep(unsigned gpio, int value) |
| 271 | { |
| 272 | might_sleep(); |
| 273 | __gpio_set_value(gpio, value); |
| 274 | } |
| 275 | |
| 276 | #endif /* !CONFIG_GPIOLIB */ |
| 277 | |
| 278 | #ifndef CONFIG_GPIO_SYSFS |
| 279 | |
| 280 | struct device; |
| 281 | |
| 282 | /* sysfs support is only available with gpiolib, where it's optional */ |
| 283 | |
| 284 | static inline int gpio_export(unsigned gpio, bool direction_may_change) |
| 285 | { |
| 286 | return -ENOSYS; |
| 287 | } |
| 288 | |
| 289 | static inline int gpio_export_link(struct device *dev, const char *name, |
| 290 | unsigned gpio) |
| 291 | { |
| 292 | return -ENOSYS; |
| 293 | } |
| 294 | |
| 295 | static inline int gpio_sysfs_set_active_low(unsigned gpio, int value) |
| 296 | { |
| 297 | return -ENOSYS; |
| 298 | } |
| 299 | |
| 300 | static inline void gpio_unexport(unsigned gpio) |
| 301 | { |
| 302 | } |
| 303 | #endif /* CONFIG_GPIO_SYSFS */ |
| 304 | |
| 305 | #endif /* _ASM_GENERIC_GPIO_H */ |