xref: /openbmc/linux/include/linux/gpio/driver.h (revision b802fb99ae964681d1754428f67970911e0476e9)
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/lockdep.h>
10 #include <linux/pinctrl/pinctrl.h>
11 #include <linux/kconfig.h>
12 
13 struct device;
14 struct gpio_desc;
15 struct of_phandle_args;
16 struct device_node;
17 struct seq_file;
18 
19 #ifdef CONFIG_GPIOLIB
20 
21 /**
22  * struct gpio_chip - abstract a GPIO controller
23  * @label: for diagnostics
24  * @parent: optional parent device providing the GPIOs
25  * @cdev: class device used by sysfs interface (may be NULL)
26  * @owner: helps prevent removal of modules exporting active GPIOs
27  * @data: per-instance data assigned by the driver
28  * @list: links gpio_chips together for traversal
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_debounce: optional hook for setting debounce time for specified gpio in
41  *      interrupt triggered gpio chips
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  * @desc: array of ngpio descriptors. Private.
56  * @names: if set, must be an array of strings to use as alternative
57  *      names for the GPIOs in this chip. Any entry in the array
58  *      may be NULL if there is no alias for the GPIO, however the
59  *      array must be @ngpio entries long.  A name can include a single printk
60  *      format specifier for an unsigned int.  It is substituted by the actual
61  *      number of the gpio.
62  * @can_sleep: flag must be set iff get()/set() methods sleep, as they
63  *	must while accessing GPIO expander chips over I2C or SPI. This
64  *	implies that if the chip supports IRQs, these IRQs need to be threaded
65  *	as the chip access may sleep when e.g. reading out the IRQ status
66  *	registers.
67  * @irq_not_threaded: flag must be set if @can_sleep is set but the
68  *	IRQs don't need to be threaded
69  * @read_reg: reader function for generic GPIO
70  * @write_reg: writer function for generic GPIO
71  * @pin2mask: some generic GPIO controllers work with the big-endian bits
72  *	notation, e.g. in a 8-bits register, GPIO7 is the least significant
73  *	bit. This callback assigns the right bit mask.
74  * @reg_dat: data (in) register for generic GPIO
75  * @reg_set: output set register (out=high) for generic GPIO
76  * @reg_clk: output clear register (out=low) for generic GPIO
77  * @reg_dir: direction setting register for generic GPIO
78  * @bgpio_bits: number of register bits used for a generic GPIO i.e.
79  *	<register width> * 8
80  * @bgpio_lock: used to lock chip->bgpio_data. Also, this is needed to keep
81  *	shadowed and real data registers writes together.
82  * @bgpio_data:	shadowed data register for generic GPIO to clear/set bits
83  *	safely.
84  * @bgpio_dir: shadowed direction register for generic GPIO to clear/set
85  *	direction safely.
86  * @irqchip: GPIO IRQ chip impl, provided by GPIO driver
87  * @irqdomain: Interrupt translation domain; responsible for mapping
88  *	between GPIO hwirq number and linux irq number
89  * @irq_base: first linux IRQ number assigned to GPIO IRQ chip (deprecated)
90  * @irq_handler: the irq handler to use (often a predefined irq core function)
91  *	for GPIO IRQs, provided by GPIO driver
92  * @irq_default_type: default IRQ triggering type applied during GPIO driver
93  *	initialization, provided by GPIO driver
94  * @irq_parent: GPIO IRQ chip parent/bank linux irq number,
95  *	provided by GPIO driver
96  * @lock_key: per GPIO IRQ chip lockdep class
97  *
98  * A gpio_chip can help platforms abstract various sources of GPIOs so
99  * they can all be accessed through a common programing interface.
100  * Example sources would be SOC controllers, FPGAs, multifunction
101  * chips, dedicated GPIO expanders, and so on.
102  *
103  * Each chip controls a number of signals, identified in method calls
104  * by "offset" values in the range 0..(@ngpio - 1).  When those signals
105  * are referenced through calls like gpio_get_value(gpio), the offset
106  * is calculated by subtracting @base from the gpio number.
107  */
108 struct gpio_chip {
109 	const char		*label;
110 	struct device		*parent;
111 	struct device		*cdev;
112 	struct module		*owner;
113 	void			*data;
114 	struct list_head        list;
115 
116 	int			(*request)(struct gpio_chip *chip,
117 						unsigned offset);
118 	void			(*free)(struct gpio_chip *chip,
119 						unsigned offset);
120 	int			(*get_direction)(struct gpio_chip *chip,
121 						unsigned offset);
122 	int			(*direction_input)(struct gpio_chip *chip,
123 						unsigned offset);
124 	int			(*direction_output)(struct gpio_chip *chip,
125 						unsigned offset, int value);
126 	int			(*get)(struct gpio_chip *chip,
127 						unsigned offset);
128 	void			(*set)(struct gpio_chip *chip,
129 						unsigned offset, int value);
130 	void			(*set_multiple)(struct gpio_chip *chip,
131 						unsigned long *mask,
132 						unsigned long *bits);
133 	int			(*set_debounce)(struct gpio_chip *chip,
134 						unsigned offset,
135 						unsigned debounce);
136 
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 	struct gpio_desc	*desc;
145 	const char		*const *names;
146 	bool			can_sleep;
147 	bool			irq_not_threaded;
148 
149 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
150 	unsigned long (*read_reg)(void __iomem *reg);
151 	void (*write_reg)(void __iomem *reg, unsigned long data);
152 	unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
153 	void __iomem *reg_dat;
154 	void __iomem *reg_set;
155 	void __iomem *reg_clr;
156 	void __iomem *reg_dir;
157 	int bgpio_bits;
158 	spinlock_t bgpio_lock;
159 	unsigned long bgpio_data;
160 	unsigned long bgpio_dir;
161 #endif
162 
163 #ifdef CONFIG_GPIOLIB_IRQCHIP
164 	/*
165 	 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
166 	 * to handle IRQs for most practical cases.
167 	 */
168 	struct irq_chip		*irqchip;
169 	struct irq_domain	*irqdomain;
170 	unsigned int		irq_base;
171 	irq_flow_handler_t	irq_handler;
172 	unsigned int		irq_default_type;
173 	int			irq_parent;
174 	struct lock_class_key	*lock_key;
175 #endif
176 
177 #if defined(CONFIG_OF_GPIO)
178 	/*
179 	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
180 	 * device tree automatically may have an OF translation
181 	 */
182 	struct device_node *of_node;
183 	int of_gpio_n_cells;
184 	int (*of_xlate)(struct gpio_chip *gc,
185 			const struct of_phandle_args *gpiospec, u32 *flags);
186 #endif
187 #ifdef CONFIG_PINCTRL
188 	/*
189 	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
190 	 * describe the actual pin range which they serve in an SoC. This
191 	 * information would be used by pinctrl subsystem to configure
192 	 * corresponding pins for gpio usage.
193 	 */
194 	struct list_head pin_ranges;
195 #endif
196 };
197 
198 extern const char *gpiochip_is_requested(struct gpio_chip *chip,
199 			unsigned offset);
200 
201 /* add/remove chips */
202 extern int gpiochip_add_data(struct gpio_chip *chip, void *data);
203 static inline int gpiochip_add(struct gpio_chip *chip)
204 {
205 	return gpiochip_add_data(chip, NULL);
206 }
207 extern void gpiochip_remove(struct gpio_chip *chip);
208 extern struct gpio_chip *gpiochip_find(void *data,
209 			      int (*match)(struct gpio_chip *chip, void *data));
210 
211 /* lock/unlock as IRQ */
212 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
213 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
214 
215 /* get driver data */
216 static inline void *gpiochip_get_data(struct gpio_chip *chip)
217 {
218 	return chip->data;
219 }
220 
221 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
222 
223 struct bgpio_pdata {
224 	const char *label;
225 	int base;
226 	int ngpio;
227 };
228 
229 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
230 
231 int bgpio_init(struct gpio_chip *gc, struct device *dev,
232 	       unsigned long sz, void __iomem *dat, void __iomem *set,
233 	       void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
234 	       unsigned long flags);
235 
236 #define BGPIOF_BIG_ENDIAN		BIT(0)
237 #define BGPIOF_UNREADABLE_REG_SET	BIT(1) /* reg_set is unreadable */
238 #define BGPIOF_UNREADABLE_REG_DIR	BIT(2) /* reg_dir is unreadable */
239 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER	BIT(3)
240 #define BGPIOF_READ_OUTPUT_REG_SET	BIT(4) /* reg_set stores output value */
241 #define BGPIOF_NO_OUTPUT		BIT(5) /* only input */
242 
243 #endif
244 
245 #ifdef CONFIG_GPIOLIB_IRQCHIP
246 
247 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
248 		struct irq_chip *irqchip,
249 		int parent_irq,
250 		irq_flow_handler_t parent_handler);
251 
252 int _gpiochip_irqchip_add(struct gpio_chip *gpiochip,
253 			  struct irq_chip *irqchip,
254 			  unsigned int first_irq,
255 			  irq_flow_handler_t handler,
256 			  unsigned int type,
257 			  struct lock_class_key *lock_key);
258 
259 #ifdef CONFIG_LOCKDEP
260 #define gpiochip_irqchip_add(...)				\
261 (								\
262 	({							\
263 		static struct lock_class_key _key;		\
264 		_gpiochip_irqchip_add(__VA_ARGS__, &_key);	\
265 	})							\
266 )
267 #else
268 #define gpiochip_irqchip_add(...)				\
269 	_gpiochip_irqchip_add(__VA_ARGS__, NULL)
270 #endif
271 
272 #endif /* CONFIG_GPIOLIB_IRQCHIP */
273 
274 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
275 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
276 
277 #ifdef CONFIG_PINCTRL
278 
279 /**
280  * struct gpio_pin_range - pin range controlled by a gpio chip
281  * @head: list for maintaining set of pin ranges, used internally
282  * @pctldev: pinctrl device which handles corresponding pins
283  * @range: actual range of pins controlled by a gpio controller
284  */
285 
286 struct gpio_pin_range {
287 	struct list_head node;
288 	struct pinctrl_dev *pctldev;
289 	struct pinctrl_gpio_range range;
290 };
291 
292 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
293 			   unsigned int gpio_offset, unsigned int pin_offset,
294 			   unsigned int npins);
295 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
296 			struct pinctrl_dev *pctldev,
297 			unsigned int gpio_offset, const char *pin_group);
298 void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
299 
300 #else
301 
302 static inline int
303 gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
304 		       unsigned int gpio_offset, unsigned int pin_offset,
305 		       unsigned int npins)
306 {
307 	return 0;
308 }
309 static inline int
310 gpiochip_add_pingroup_range(struct gpio_chip *chip,
311 			struct pinctrl_dev *pctldev,
312 			unsigned int gpio_offset, const char *pin_group)
313 {
314 	return 0;
315 }
316 
317 static inline void
318 gpiochip_remove_pin_ranges(struct gpio_chip *chip)
319 {
320 }
321 
322 #endif /* CONFIG_PINCTRL */
323 
324 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
325 					    const char *label);
326 void gpiochip_free_own_desc(struct gpio_desc *desc);
327 
328 #else /* CONFIG_GPIOLIB */
329 
330 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
331 {
332 	/* GPIO can never have been requested */
333 	WARN_ON(1);
334 	return ERR_PTR(-ENODEV);
335 }
336 
337 #endif /* CONFIG_GPIOLIB */
338 
339 #endif
340