xref: /openbmc/linux/include/linux/gpio/driver.h (revision a36954f5)
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/pinctrl/pinconf-generic.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  * struct gpio_chip - abstract a GPIO controller
24  * @label: a functional name for the GPIO device, such as a part
25  *	number or the name of the SoC IP-block implementing it.
26  * @gpiodev: the internal state holder, opaque struct
27  * @parent: optional parent device providing the GPIOs
28  * @owner: helps prevent removal of modules exporting active GPIOs
29  * @request: optional hook for chip-specific activation, such as
30  *	enabling module power and clock; may sleep
31  * @free: optional hook for chip-specific deactivation, such as
32  *	disabling module power and clock; may sleep
33  * @get_direction: returns direction for signal "offset", 0=out, 1=in,
34  *	(same as GPIOF_DIR_XXX), or negative error
35  * @direction_input: configures signal "offset" as input, or returns error
36  * @direction_output: configures signal "offset" as output, or returns error
37  * @get: returns value for signal "offset", 0=low, 1=high, or negative error
38  * @set: assigns output value for signal "offset"
39  * @set_multiple: assigns output values for multiple signals defined by "mask"
40  * @set_config: optional hook for all kinds of settings. Uses the same
41  *	packed config format as generic pinconf.
42  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
43  *	implementation may not sleep
44  * @dbg_show: optional routine to show contents in debugfs; default code
45  *	will be used when this is omitted, but custom code can show extra
46  *	state (such as pullup/pulldown configuration).
47  * @base: identifies the first GPIO number handled by this chip;
48  *	or, if negative during registration, requests dynamic ID allocation.
49  *	DEPRECATION: providing anything non-negative and nailing the base
50  *	offset of GPIO chips is deprecated. Please pass -1 as base to
51  *	let gpiolib select the chip base in all possible cases. We want to
52  *	get rid of the static GPIO number space in the long run.
53  * @ngpio: the number of GPIOs handled by this controller; the last GPIO
54  *	handled is (base + ngpio - 1).
55  * @names: if set, must be an array of strings to use as alternative
56  *      names for the GPIOs in this chip. Any entry in the array
57  *      may be NULL if there is no alias for the GPIO, however the
58  *      array must be @ngpio entries long.  A name can include a single printk
59  *      format specifier for an unsigned int.  It is substituted by the actual
60  *      number of the gpio.
61  * @can_sleep: flag must be set iff get()/set() methods sleep, as they
62  *	must while accessing GPIO expander chips over I2C or SPI. This
63  *	implies that if the chip supports IRQs, these IRQs need to be threaded
64  *	as the chip access may sleep when e.g. reading out the IRQ status
65  *	registers.
66  * @read_reg: reader function for generic GPIO
67  * @write_reg: writer function for generic GPIO
68  * @pin2mask: some generic GPIO controllers work with the big-endian bits
69  *	notation, e.g. in a 8-bits register, GPIO7 is the least significant
70  *	bit. This callback assigns the right bit mask.
71  * @reg_dat: data (in) register for generic GPIO
72  * @reg_set: output set register (out=high) for generic GPIO
73  * @reg_clr: output clear register (out=low) for generic GPIO
74  * @reg_dir: direction setting register for generic GPIO
75  * @bgpio_bits: number of register bits used for a generic GPIO i.e.
76  *	<register width> * 8
77  * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
78  *	shadowed and real data registers writes together.
79  * @bgpio_data:	shadowed data register for generic GPIO to clear/set bits
80  *	safely.
81  * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
82  *	direction safely.
83  * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
84  * @irqdomain: Interrupt translation domain; responsible for mapping
85  *	between GPIO hwirq number and linux irq number
86  * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
87  * @irq_handler: the irq handler to use (often a predefined irq core function)
88  *	for GPIO IRQs, provided by GPIO driver
89  * @irq_default_type: default IRQ triggering type applied during GPIO driver
90  *	initialization, provided by GPIO driver
91  * @irq_chained_parent: GPIO IRQ chip parent/bank linux irq number,
92  *	provided by GPIO driver for chained interrupt (not for nested
93  *	interrupts).
94  * @irq_nested: True if set the interrupt handling is nested.
95  * @irq_need_valid_mask: If set core allocates @irq_valid_mask with all
96  *	bits set to one
97  * @irq_valid_mask: If not %NULL holds bitmask of GPIOs which are valid to
98  *	be included in IRQ domain of the chip
99  * @lock_key: per GPIO IRQ chip lockdep class
100  *
101  * A gpio_chip can help platforms abstract various sources of GPIOs so
102  * they can all be accessed through a common programing interface.
103  * Example sources would be SOC controllers, FPGAs, multifunction
104  * chips, dedicated GPIO expanders, and so on.
105  *
106  * Each chip controls a number of signals, identified in method calls
107  * by "offset" values in the range 0..(@ngpio - 1).  When those signals
108  * are referenced through calls like gpio_get_value(gpio), the offset
109  * is calculated by subtracting @base from the gpio number.
110  */
111 struct gpio_chip {
112 	const char		*label;
113 	struct gpio_device	*gpiodev;
114 	struct device		*parent;
115 	struct module		*owner;
116 
117 	int			(*request)(struct gpio_chip *chip,
118 						unsigned offset);
119 	void			(*free)(struct gpio_chip *chip,
120 						unsigned offset);
121 	int			(*get_direction)(struct gpio_chip *chip,
122 						unsigned offset);
123 	int			(*direction_input)(struct gpio_chip *chip,
124 						unsigned offset);
125 	int			(*direction_output)(struct gpio_chip *chip,
126 						unsigned offset, int value);
127 	int			(*get)(struct gpio_chip *chip,
128 						unsigned offset);
129 	void			(*set)(struct gpio_chip *chip,
130 						unsigned offset, int value);
131 	void			(*set_multiple)(struct gpio_chip *chip,
132 						unsigned long *mask,
133 						unsigned long *bits);
134 	int			(*set_config)(struct gpio_chip *chip,
135 					      unsigned offset,
136 					      unsigned long config);
137 	int			(*to_irq)(struct gpio_chip *chip,
138 						unsigned offset);
139 
140 	void			(*dbg_show)(struct seq_file *s,
141 						struct gpio_chip *chip);
142 	int			base;
143 	u16			ngpio;
144 	const char		*const *names;
145 	bool			can_sleep;
146 
147 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
148 	unsigned long (*read_reg)(void __iomem *reg);
149 	void (*write_reg)(void __iomem *reg, unsigned long data);
150 	unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
151 	void __iomem *reg_dat;
152 	void __iomem *reg_set;
153 	void __iomem *reg_clr;
154 	void __iomem *reg_dir;
155 	int bgpio_bits;
156 	spinlock_t bgpio_lock;
157 	unsigned long bgpio_data;
158 	unsigned long bgpio_dir;
159 #endif
160 
161 #ifdef CONFIG_GPIOLIB_IRQCHIP
162 	/*
163 	 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
164 	 * to handle IRQs for most practical cases.
165 	 */
166 	struct irq_chip		*irqchip;
167 	struct irq_domain	*irqdomain;
168 	unsigned int		irq_base;
169 	irq_flow_handler_t	irq_handler;
170 	unsigned int		irq_default_type;
171 	unsigned int		irq_chained_parent;
172 	bool			irq_nested;
173 	bool			irq_need_valid_mask;
174 	unsigned long		*irq_valid_mask;
175 	struct lock_class_key	*lock_key;
176 #endif
177 
178 #if defined(CONFIG_OF_GPIO)
179 	/*
180 	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
181 	 * device tree automatically may have an OF translation
182 	 */
183 	struct device_node *of_node;
184 	int of_gpio_n_cells;
185 	int (*of_xlate)(struct gpio_chip *gc,
186 			const struct of_phandle_args *gpiospec, u32 *flags);
187 #endif
188 };
189 
190 extern const char *gpiochip_is_requested(struct gpio_chip *chip,
191 			unsigned offset);
192 
193 /* add/remove chips */
194 extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
195 static inline int gpiochip_add(struct gpio_chip *chip)
196 {
197 	return gpiochip_add_data(chip, NULL);
198 }
199 extern void gpiochip_remove(struct gpio_chip *chip);
200 extern int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
201 				  void *data);
202 extern void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip);
203 
204 extern struct gpio_chip *gpiochip_find(void *data,
205 			      int (*match)(struct gpio_chip *chip, void *data));
206 
207 /* lock/unlock as IRQ */
208 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
209 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
210 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
211 
212 /* Line status inquiry for drivers */
213 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
214 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
215 
216 /* get driver data */
217 void *gpiochip_get_data(struct gpio_chip *chip);
218 
219 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
220 
221 struct bgpio_pdata {
222 	const char *label;
223 	int base;
224 	int ngpio;
225 };
226 
227 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
228 
229 int bgpio_init(struct gpio_chip *gc, struct device *dev,
230 	       unsigned long sz, void __iomem *dat, void __iomem *set,
231 	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
232 	       unsigned long flags);
233 
234 #define BGPIOF_BIG_ENDIAN		BIT(0)
235 #define BGPIOF_UNREADABLE_REG_SET	BIT(1) /* reg_set is unreadable */
236 #define BGPIOF_UNREADABLE_REG_DIR	BIT(2) /* reg_dir is unreadable */
237 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER	BIT(3)
238 #define BGPIOF_READ_OUTPUT_REG_SET	BIT(4) /* reg_set stores output value */
239 #define BGPIOF_NO_OUTPUT		BIT(5) /* only input */
240 
241 #endif
242 
243 #ifdef CONFIG_GPIOLIB_IRQCHIP
244 
245 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
246 		struct irq_chip *irqchip,
247 		unsigned int parent_irq,
248 		irq_flow_handler_t parent_handler);
249 
250 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
251 		struct irq_chip *irqchip,
252 		unsigned int parent_irq);
253 
254 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
255 			     struct irq_chip *irqchip,
256 			     unsigned int first_irq,
257 			     irq_flow_handler_t handler,
258 			     unsigned int type,
259 			     bool nested,
260 			     struct lock_class_key *lock_key);
261 
262 #ifdef CONFIG_LOCKDEP
263 
264 /*
265  * Lockdep requires that each irqchip instance be created with a
266  * unique key so as to avoid unnecessary warnings. This upfront
267  * boilerplate static inlines provides such a key for each
268  * unique instance.
269  */
270 static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
271 				       struct irq_chip *irqchip,
272 				       unsigned int first_irq,
273 				       irq_flow_handler_t handler,
274 				       unsigned int type)
275 {
276 	static struct lock_class_key key;
277 
278 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
279 					handler, type, false, &key);
280 }
281 
282 static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
283 			  struct irq_chip *irqchip,
284 			  unsigned int first_irq,
285 			  irq_flow_handler_t handler,
286 			  unsigned int type)
287 {
288 
289 	static struct lock_class_key key;
290 
291 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
292 					handler, type, true, &key);
293 }
294 #else
295 static inline int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
296 				       struct irq_chip *irqchip,
297 				       unsigned int first_irq,
298 				       irq_flow_handler_t handler,
299 				       unsigned int type)
300 {
301 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
302 					handler, type, false, NULL);
303 }
304 
305 static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
306 			  struct irq_chip *irqchip,
307 			  unsigned int first_irq,
308 			  irq_flow_handler_t handler,
309 			  unsigned int type)
310 {
311 	return gpiochip_irqchip_add_key(gpiochip, irqchip, first_irq,
312 					handler, type, true, NULL);
313 }
314 #endif /* CONFIG_LOCKDEP */
315 
316 #endif /* CONFIG_GPIOLIB_IRQCHIP */
317 
318 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
319 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
320 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
321 			    unsigned long config);
322 
323 #ifdef CONFIG_PINCTRL
324 
325 /**
326  * struct gpio_pin_range - pin range controlled by a gpio chip
327  * @head: list for maintaining set of pin ranges, used internally
328  * @pctldev: pinctrl device which handles corresponding pins
329  * @range: actual range of pins controlled by a gpio controller
330  */
331 
332 struct gpio_pin_range {
333 	struct list_head node;
334 	struct pinctrl_dev *pctldev;
335 	struct pinctrl_gpio_range range;
336 };
337 
338 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
339 			   unsigned int gpio_offset, unsigned int pin_offset,
340 			   unsigned int npins);
341 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
342 			struct pinctrl_dev *pctldev,
343 			unsigned int gpio_offset, const char *pin_group);
344 void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
345 
346 #else
347 
348 static inline int
349 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
350 		       unsigned int gpio_offset, unsigned int pin_offset,
351 		       unsigned int npins)
352 {
353 	return 0;
354 }
355 static inline int
356 gpiochip_add_pingroup_range(struct gpio_chip *chip,
357 			struct pinctrl_dev *pctldev,
358 			unsigned int gpio_offset, const char *pin_group)
359 {
360 	return 0;
361 }
362 
363 static inline void
364 gpiochip_remove_pin_ranges(struct gpio_chip *chip)
365 {
366 }
367 
368 #endif /* CONFIG_PINCTRL */
369 
370 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
371 					    const char *label);
372 void gpiochip_free_own_desc(struct gpio_desc *desc);
373 
374 #else /* CONFIG_GPIOLIB */
375 
376 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
377 {
378 	/* GPIO can never have been requested */
379 	WARN_ON(1);
380 	return ERR_PTR(-ENODEV);
381 }
382 
383 #endif /* CONFIG_GPIOLIB */
384 
385 #endif
386