1 #ifndef __LINUX_GPIO_DRIVER_H 2 #define __LINUX_GPIO_DRIVER_H 3 4 #include <linux/types.h> 5 #include <linux/module.h> 6 #include <linux/irq.h> 7 #include <linux/irqchip/chained_irq.h> 8 #include <linux/irqdomain.h> 9 #include <linux/pinctrl/pinctrl.h> 10 11 struct device; 12 struct gpio_desc; 13 struct of_phandle_args; 14 struct device_node; 15 struct seq_file; 16 17 #ifdef CONFIG_GPIOLIB 18 19 /** 20 * struct gpio_chip - abstract a GPIO controller 21 * @label: for diagnostics 22 * @dev: optional device providing the GPIOs 23 * @owner: helps prevent removal of modules exporting active GPIOs 24 * @list: links gpio_chips together for traversal 25 * @request: optional hook for chip-specific activation, such as 26 * enabling module power and clock; may sleep 27 * @free: optional hook for chip-specific deactivation, such as 28 * disabling module power and clock; may sleep 29 * @get_direction: returns direction for signal "offset", 0=out, 1=in, 30 * (same as GPIOF_DIR_XXX), or negative error 31 * @direction_input: configures signal "offset" as input, or returns error 32 * @direction_output: configures signal "offset" as output, or returns error 33 * @get: returns value for signal "offset"; for output signals this 34 * returns either the value actually sensed, or zero 35 * @set: assigns output value for signal "offset" 36 * @set_multiple: assigns output values for multiple signals defined by "mask" 37 * @set_debounce: optional hook for setting debounce time for specified gpio in 38 * interrupt triggered gpio chips 39 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings; 40 * implementation may not sleep 41 * @dbg_show: optional routine to show contents in debugfs; default code 42 * will be used when this is omitted, but custom code can show extra 43 * state (such as pullup/pulldown configuration). 44 * @base: identifies the first GPIO number handled by this chip; or, if 45 * negative during registration, requests dynamic ID allocation. 46 * @ngpio: the number of GPIOs handled by this controller; the last GPIO 47 * handled is (base + ngpio - 1). 48 * @desc: array of ngpio descriptors. Private. 49 * @names: if set, must be an array of strings to use as alternative 50 * names for the GPIOs in this chip. Any entry in the array 51 * may be NULL if there is no alias for the GPIO, however the 52 * array must be @ngpio entries long. A name can include a single printk 53 * format specifier for an unsigned int. It is substituted by the actual 54 * number of the gpio. 55 * @can_sleep: flag must be set iff get()/set() methods sleep, as they 56 * must while accessing GPIO expander chips over I2C or SPI. This 57 * implies that if the chip supports IRQs, these IRQs need to be threaded 58 * as the chip access may sleep when e.g. reading out the IRQ status 59 * registers. 60 * @exported: flags if the gpiochip is exported for use from sysfs. Private. 61 * @irq_not_threaded: flag must be set if @can_sleep is set but the 62 * IRQs don't need to be threaded 63 * 64 * A gpio_chip can help platforms abstract various sources of GPIOs so 65 * they can all be accessed through a common programing interface. 66 * Example sources would be SOC controllers, FPGAs, multifunction 67 * chips, dedicated GPIO expanders, and so on. 68 * 69 * Each chip controls a number of signals, identified in method calls 70 * by "offset" values in the range 0..(@ngpio - 1). When those signals 71 * are referenced through calls like gpio_get_value(gpio), the offset 72 * is calculated by subtracting @base from the gpio number. 73 */ 74 struct gpio_chip { 75 const char *label; 76 struct device *dev; 77 struct module *owner; 78 struct list_head list; 79 80 int (*request)(struct gpio_chip *chip, 81 unsigned offset); 82 void (*free)(struct gpio_chip *chip, 83 unsigned offset); 84 int (*get_direction)(struct gpio_chip *chip, 85 unsigned offset); 86 int (*direction_input)(struct gpio_chip *chip, 87 unsigned offset); 88 int (*direction_output)(struct gpio_chip *chip, 89 unsigned offset, int value); 90 int (*get)(struct gpio_chip *chip, 91 unsigned offset); 92 void (*set)(struct gpio_chip *chip, 93 unsigned offset, int value); 94 void (*set_multiple)(struct gpio_chip *chip, 95 unsigned long *mask, 96 unsigned long *bits); 97 int (*set_debounce)(struct gpio_chip *chip, 98 unsigned offset, 99 unsigned debounce); 100 101 int (*to_irq)(struct gpio_chip *chip, 102 unsigned offset); 103 104 void (*dbg_show)(struct seq_file *s, 105 struct gpio_chip *chip); 106 int base; 107 u16 ngpio; 108 struct gpio_desc *desc; 109 const char *const *names; 110 bool can_sleep; 111 bool irq_not_threaded; 112 bool exported; 113 114 #ifdef CONFIG_GPIOLIB_IRQCHIP 115 /* 116 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib 117 * to handle IRQs for most practical cases. 118 */ 119 struct irq_chip *irqchip; 120 struct irq_domain *irqdomain; 121 unsigned int irq_base; 122 irq_flow_handler_t irq_handler; 123 unsigned int irq_default_type; 124 #endif 125 126 #if defined(CONFIG_OF_GPIO) 127 /* 128 * If CONFIG_OF is enabled, then all GPIO controllers described in the 129 * device tree automatically may have an OF translation 130 */ 131 struct device_node *of_node; 132 int of_gpio_n_cells; 133 int (*of_xlate)(struct gpio_chip *gc, 134 const struct of_phandle_args *gpiospec, u32 *flags); 135 #endif 136 #ifdef CONFIG_PINCTRL 137 /* 138 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally 139 * describe the actual pin range which they serve in an SoC. This 140 * information would be used by pinctrl subsystem to configure 141 * corresponding pins for gpio usage. 142 */ 143 struct list_head pin_ranges; 144 #endif 145 }; 146 147 extern const char *gpiochip_is_requested(struct gpio_chip *chip, 148 unsigned offset); 149 150 /* add/remove chips */ 151 extern int gpiochip_add(struct gpio_chip *chip); 152 extern void gpiochip_remove(struct gpio_chip *chip); 153 extern struct gpio_chip *gpiochip_find(void *data, 154 int (*match)(struct gpio_chip *chip, void *data)); 155 156 /* lock/unlock as IRQ */ 157 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset); 158 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset); 159 160 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc); 161 162 #ifdef CONFIG_GPIOLIB_IRQCHIP 163 164 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, 165 struct irq_chip *irqchip, 166 int parent_irq, 167 irq_flow_handler_t parent_handler); 168 169 int gpiochip_irqchip_add(struct gpio_chip *gpiochip, 170 struct irq_chip *irqchip, 171 unsigned int first_irq, 172 irq_flow_handler_t handler, 173 unsigned int type); 174 175 #endif /* CONFIG_GPIOLIB_IRQCHIP */ 176 177 #ifdef CONFIG_PINCTRL 178 179 /** 180 * struct gpio_pin_range - pin range controlled by a gpio chip 181 * @head: list for maintaining set of pin ranges, used internally 182 * @pctldev: pinctrl device which handles corresponding pins 183 * @range: actual range of pins controlled by a gpio controller 184 */ 185 186 struct gpio_pin_range { 187 struct list_head node; 188 struct pinctrl_dev *pctldev; 189 struct pinctrl_gpio_range range; 190 }; 191 192 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, 193 unsigned int gpio_offset, unsigned int pin_offset, 194 unsigned int npins); 195 int gpiochip_add_pingroup_range(struct gpio_chip *chip, 196 struct pinctrl_dev *pctldev, 197 unsigned int gpio_offset, const char *pin_group); 198 void gpiochip_remove_pin_ranges(struct gpio_chip *chip); 199 200 #else 201 202 static inline int 203 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, 204 unsigned int gpio_offset, unsigned int pin_offset, 205 unsigned int npins) 206 { 207 return 0; 208 } 209 static inline int 210 gpiochip_add_pingroup_range(struct gpio_chip *chip, 211 struct pinctrl_dev *pctldev, 212 unsigned int gpio_offset, const char *pin_group) 213 { 214 return 0; 215 } 216 217 static inline void 218 gpiochip_remove_pin_ranges(struct gpio_chip *chip) 219 { 220 } 221 222 #endif /* CONFIG_PINCTRL */ 223 224 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum, 225 const char *label); 226 void gpiochip_free_own_desc(struct gpio_desc *desc); 227 228 #else /* CONFIG_GPIOLIB */ 229 230 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) 231 { 232 /* GPIO can never have been requested */ 233 WARN_ON(1); 234 return ERR_PTR(-ENODEV); 235 } 236 237 #endif /* CONFIG_GPIOLIB */ 238 239 #endif 240