xref: /linux-6.15/include/linux/gpio/driver.h (revision b4f33f6d)
1 #ifndef __LINUX_GPIO_DRIVER_H
2 #define __LINUX_GPIO_DRIVER_H
3 
4 #include <linux/device.h>
5 #include <linux/types.h>
6 #include <linux/irq.h>
7 #include <linux/irqchip/chained_irq.h>
8 #include <linux/irqdomain.h>
9 #include <linux/lockdep.h>
10 #include <linux/pinctrl/pinctrl.h>
11 #include <linux/kconfig.h>
12 
13 struct gpio_desc;
14 struct of_phandle_args;
15 struct device_node;
16 struct seq_file;
17 struct gpio_device;
18 struct module;
19 
20 #ifdef CONFIG_GPIOLIB
21 
22 /**
23  * enum single_ended_mode - mode for single ended operation
24  * @LINE_MODE_PUSH_PULL: normal mode for a GPIO line, drive actively high/low
25  * @LINE_MODE_OPEN_DRAIN: set line to be open drain
26  * @LINE_MODE_OPEN_SOURCE: set line to be open source
27  */
28 enum single_ended_mode {
29 	LINE_MODE_PUSH_PULL,
30 	LINE_MODE_OPEN_DRAIN,
31 	LINE_MODE_OPEN_SOURCE,
32 };
33 
34 /**
35  * struct gpio_chip - abstract a GPIO controller
36  * @label: a functional name for the GPIO device, such as a part
37  *	number or the name of the SoC IP-block implementing it.
38  * @gpiodev: the internal state holder, opaque struct
39  * @parent: optional parent device providing the GPIOs
40  * @owner: helps prevent removal of modules exporting active GPIOs
41  * @request: optional hook for chip-specific activation, such as
42  *	enabling module power and clock; may sleep
43  * @free: optional hook for chip-specific deactivation, such as
44  *	disabling module power and clock; may sleep
45  * @get_direction: returns direction for signal "offset", 0=out, 1=in,
46  *	(same as GPIOF_DIR_XXX), or negative error
47  * @direction_input: configures signal "offset" as input, or returns error
48  * @direction_output: configures signal "offset" as output, or returns error
49  * @get: returns value for signal "offset", 0=low, 1=high, or negative error
50  * @set: assigns output value for signal "offset"
51  * @set_multiple: assigns output values for multiple signals defined by "mask"
52  * @set_debounce: optional hook for setting debounce time for specified gpio in
53  *	interrupt triggered gpio chips
54  * @set_single_ended: optional hook for setting a line as open drain, open
55  *	source, or non-single ended (restore from open drain/source to normal
56  *	push-pull mode) this should be implemented if the hardware supports
57  *	open drain or open source settings. The GPIOlib will otherwise try
58  *	to emulate open drain/source by not actively driving lines high/low
59  *	if a consumer request this. The driver may return -ENOTSUPP if e.g.
60  *	it supports just open drain but not open source and is called
61  *	with LINE_MODE_OPEN_SOURCE as mode argument.
62  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
63  *	implementation may not sleep
64  * @dbg_show: optional routine to show contents in debugfs; default code
65  *	will be used when this is omitted, but custom code can show extra
66  *	state (such as pullup/pulldown configuration).
67  * @base: identifies the first GPIO number handled by this chip;
68  *	or, if negative during registration, requests dynamic ID allocation.
69  *	DEPRECATION: providing anything non-negative and nailing the base
70  *	offset of GPIO chips is deprecated. Please pass -1 as base to
71  *	let gpiolib select the chip base in all possible cases. We want to
72  *	get rid of the static GPIO number space in the long run.
73  * @ngpio: the number of GPIOs handled by this controller; the last GPIO
74  *	handled is (base + ngpio - 1).
75  * @names: if set, must be an array of strings to use as alternative
76  *      names for the GPIOs in this chip. Any entry in the array
77  *      may be NULL if there is no alias for the GPIO, however the
78  *      array must be @ngpio entries long.  A name can include a single printk
79  *      format specifier for an unsigned int.  It is substituted by the actual
80  *      number of the gpio.
81  * @can_sleep: flag must be set iff get()/set() methods sleep, as they
82  *	must while accessing GPIO expander chips over I2C or SPI. This
83  *	implies that if the chip supports IRQs, these IRQs need to be threaded
84  *	as the chip access may sleep when e.g. reading out the IRQ status
85  *	registers.
86  * @irq_not_threaded: flag must be set if @can_sleep is set but the
87  *	IRQs don't need to be threaded
88  * @read_reg: reader function for generic GPIO
89  * @write_reg: writer function for generic GPIO
90  * @pin2mask: some generic GPIO controllers work with the big-endian bits
91  *	notation, e.g. in a 8-bits register, GPIO7 is the least significant
92  *	bit. This callback assigns the right bit mask.
93  * @reg_dat: data (in) register for generic GPIO
94  * @reg_set: output set register (out=high) for generic GPIO
95  * @reg_clk: output clear register (out=low) for generic GPIO
96  * @reg_dir: direction setting register for generic GPIO
97  * @bgpio_bits: number of register bits used for a generic GPIO i.e.
98  *	<register width> * 8
99  * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
100  *	shadowed and real data registers writes together.
101  * @bgpio_data:	shadowed data register for generic GPIO to clear/set bits
102  *	safely.
103  * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
104  *	direction safely.
105  * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
106  * @irqdomain: Interrupt translation domain; responsible for mapping
107  *	between GPIO hwirq number and linux irq number
108  * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
109  * @irq_handler: the irq handler to use (often a predefined irq core function)
110  *	for GPIO IRQs, provided by GPIO driver
111  * @irq_default_type: default IRQ triggering type applied during GPIO driver
112  *	initialization, provided by GPIO driver
113  * @irq_parent: GPIO IRQ chip parent/bank linux irq number,
114  *	provided by GPIO driver
115  * @irq_need_valid_mask: If set core allocates @irq_valid_mask with all
116  *	bits set to one
117  * @irq_valid_mask: If not %NULL holds bitmask of GPIOs which are valid to
118  *	be included in IRQ domain of the chip
119  * @lock_key: per GPIO IRQ chip lockdep class
120  *
121  * A gpio_chip can help platforms abstract various sources of GPIOs so
122  * they can all be accessed through a common programing interface.
123  * Example sources would be SOC controllers, FPGAs, multifunction
124  * chips, dedicated GPIO expanders, and so on.
125  *
126  * Each chip controls a number of signals, identified in method calls
127  * by "offset" values in the range 0..(@ngpio - 1).  When those signals
128  * are referenced through calls like gpio_get_value(gpio), the offset
129  * is calculated by subtracting @base from the gpio number.
130  */
131 struct gpio_chip {
132 	const char		*label;
133 	struct gpio_device	*gpiodev;
134 	struct device		*parent;
135 	struct module		*owner;
136 
137 	int			(*request)(struct gpio_chip *chip,
138 						unsigned offset);
139 	void			(*free)(struct gpio_chip *chip,
140 						unsigned offset);
141 	int			(*get_direction)(struct gpio_chip *chip,
142 						unsigned offset);
143 	int			(*direction_input)(struct gpio_chip *chip,
144 						unsigned offset);
145 	int			(*direction_output)(struct gpio_chip *chip,
146 						unsigned offset, int value);
147 	int			(*get)(struct gpio_chip *chip,
148 						unsigned offset);
149 	void			(*set)(struct gpio_chip *chip,
150 						unsigned offset, int value);
151 	void			(*set_multiple)(struct gpio_chip *chip,
152 						unsigned long *mask,
153 						unsigned long *bits);
154 	int			(*set_debounce)(struct gpio_chip *chip,
155 						unsigned offset,
156 						unsigned debounce);
157 	int			(*set_single_ended)(struct gpio_chip *chip,
158 						unsigned offset,
159 						enum single_ended_mode mode);
160 
161 	int			(*to_irq)(struct gpio_chip *chip,
162 						unsigned offset);
163 
164 	void			(*dbg_show)(struct seq_file *s,
165 						struct gpio_chip *chip);
166 	int			base;
167 	u16			ngpio;
168 	const char		*const *names;
169 	bool			can_sleep;
170 	bool			irq_not_threaded;
171 
172 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
173 	unsigned long (*read_reg)(void __iomem *reg);
174 	void (*write_reg)(void __iomem *reg, unsigned long data);
175 	unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
176 	void __iomem *reg_dat;
177 	void __iomem *reg_set;
178 	void __iomem *reg_clr;
179 	void __iomem *reg_dir;
180 	int bgpio_bits;
181 	spinlock_t bgpio_lock;
182 	unsigned long bgpio_data;
183 	unsigned long bgpio_dir;
184 #endif
185 
186 #ifdef CONFIG_GPIOLIB_IRQCHIP
187 	/*
188 	 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
189 	 * to handle IRQs for most practical cases.
190 	 */
191 	struct irq_chip		*irqchip;
192 	struct irq_domain	*irqdomain;
193 	unsigned int		irq_base;
194 	irq_flow_handler_t	irq_handler;
195 	unsigned int		irq_default_type;
196 	int			irq_parent;
197 	bool			irq_need_valid_mask;
198 	unsigned long		*irq_valid_mask;
199 	struct lock_class_key	*lock_key;
200 #endif
201 
202 #if defined(CONFIG_OF_GPIO)
203 	/*
204 	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
205 	 * device tree automatically may have an OF translation
206 	 */
207 	struct device_node *of_node;
208 	int of_gpio_n_cells;
209 	int (*of_xlate)(struct gpio_chip *gc,
210 			const struct of_phandle_args *gpiospec, u32 *flags);
211 #endif
212 };
213 
214 extern const char *gpiochip_is_requested(struct gpio_chip *chip,
215 			unsigned offset);
216 
217 /* add/remove chips */
218 extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
219 static inline int gpiochip_add(struct gpio_chip *chip)
220 {
221 	return gpiochip_add_data(chip, NULL);
222 }
223 extern void gpiochip_remove(struct gpio_chip *chip);
224 extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
225 				  void *data);
226 extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
227 
228 extern struct gpio_chip *gpiochip_find(void *data,
229 			      int (*match)(struct gpio_chip *chip, void *data));
230 
231 /* lock/unlock as IRQ */
232 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
233 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
234 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
235 
236 /* Line status inquiry for drivers */
237 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
238 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
239 
240 /* get driver data */
241 void *gpiochip_get_data(struct gpio_chip *chip);
242 
243 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
244 
245 struct bgpio_pdata {
246 	const char *label;
247 	int base;
248 	int ngpio;
249 };
250 
251 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
252 
253 int bgpio_init(struct gpio_chip *gc, struct device *dev,
254 	       unsigned long sz, void __iomem *dat, void __iomem *set,
255 	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
256 	       unsigned long flags);
257 
258 #define BGPIOF_BIG_ENDIAN		BIT(0)
259 #define BGPIOF_UNREADABLE_REG_SET	BIT(1) /* reg_set is unreadable */
260 #define BGPIOF_UNREADABLE_REG_DIR	BIT(2) /* reg_dir is unreadable */
261 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER	BIT(3)
262 #define BGPIOF_READ_OUTPUT_REG_SET	BIT(4) /* reg_set stores output value */
263 #define BGPIOF_NO_OUTPUT		BIT(5) /* only input */
264 
265 #endif
266 
267 #ifdef CONFIG_GPIOLIB_IRQCHIP
268 
269 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
270 		struct irq_chip *irqchip,
271 		int parent_irq,
272 		irq_flow_handler_t parent_handler);
273 
274 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
275 			  struct irq_chip *irqchip,
276 			  unsigned int first_irq,
277 			  irq_flow_handler_t handler,
278 			  unsigned int type,
279 			  struct lock_class_key *lock_key);
280 
281 #ifdef CONFIG_LOCKDEP
282 #define gpiochip_irqchip_add(...)				\
283 (								\
284 	({							\
285 		static struct lock_class_key _key;		\
286 		_gpiochip_irqchip_add(__VA_ARGS__, &_key);	\
287 	})							\
288 )
289 #else
290 #define gpiochip_irqchip_add(...)				\
291 	_gpiochip_irqchip_add(__VA_ARGS__, NULL)
292 #endif
293 
294 #endif /* CONFIG_GPIOLIB_IRQCHIP */
295 
296 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
297 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
298 
299 #ifdef CONFIG_PINCTRL
300 
301 /**
302  * struct gpio_pin_range - pin range controlled by a gpio chip
303  * @head: list for maintaining set of pin ranges, used internally
304  * @pctldev: pinctrl device which handles corresponding pins
305  * @range: actual range of pins controlled by a gpio controller
306  */
307 
308 struct gpio_pin_range {
309 	struct list_head node;
310 	struct pinctrl_dev *pctldev;
311 	struct pinctrl_gpio_range range;
312 };
313 
314 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
315 			   unsigned int gpio_offset, unsigned int pin_offset,
316 			   unsigned int npins);
317 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
318 			struct pinctrl_dev *pctldev,
319 			unsigned int gpio_offset, const char *pin_group);
320 void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
321 
322 #else
323 
324 static inline int
325 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
326 		       unsigned int gpio_offset, unsigned int pin_offset,
327 		       unsigned int npins)
328 {
329 	return 0;
330 }
331 static inline int
332 gpiochip_add_pingroup_range(struct gpio_chip *chip,
333 			struct pinctrl_dev *pctldev,
334 			unsigned int gpio_offset, const char *pin_group)
335 {
336 	return 0;
337 }
338 
339 static inline void
340 gpiochip_remove_pin_ranges(struct gpio_chip *chip)
341 {
342 }
343 
344 #endif /* CONFIG_PINCTRL */
345 
346 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
347 					    const char *label);
348 void gpiochip_free_own_desc(struct gpio_desc *desc);
349 
350 #else /* CONFIG_GPIOLIB */
351 
352 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
353 {
354 	/* GPIO can never have been requested */
355 	WARN_ON(1);
356 	return ERR_PTR(-ENODEV);
357 }
358 
359 #endif /* CONFIG_GPIOLIB */
360 
361 #endif
362