xref: /openbmc/linux/include/linux/gpio/regmap.h (revision 9b3c47f1)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #ifndef _LINUX_GPIO_REGMAP_H
4 #define _LINUX_GPIO_REGMAP_H
5 
6 struct device;
7 struct fwnode_handle;
8 struct gpio_regmap;
9 struct irq_domain;
10 struct regmap;
11 
12 #define GPIO_REGMAP_ADDR_ZERO ((unsigned int)(-1))
13 #define GPIO_REGMAP_ADDR(addr) ((addr) ? : GPIO_REGMAP_ADDR_ZERO)
14 
15 /**
16  * struct gpio_regmap_config - Description of a generic regmap gpio_chip.
17  * @parent:		The parent device
18  * @regmap:		The regmap used to access the registers
19  *			given, the name of the device is used
20  * @fwnode:		(Optional) The firmware node.
21  *			If not given, the fwnode of the parent is used.
22  * @label:		(Optional) Descriptive name for GPIO controller.
23  *			If not given, the name of the device is used.
24  * @ngpio:		Number of GPIOs
25  * @names:		(Optional) Array of names for gpios
26  * @reg_dat_base:	(Optional) (in) register base address
27  * @reg_set_base:	(Optional) set register base address
28  * @reg_clr_base:	(Optional) clear register base address
29  * @reg_dir_in_base:	(Optional) in setting register base address
30  * @reg_dir_out_base:	(Optional) out setting register base address
31  * @reg_stride:		(Optional) May be set if the registers (of the
32  *			same type, dat, set, etc) are not consecutive.
33  * @ngpio_per_reg:	Number of GPIOs per register
34  * @irq_domain:		(Optional) IRQ domain if the controller is
35  *			interrupt-capable
36  * @reg_mask_xlate:     (Optional) Translates base address and GPIO
37  *			offset to a register/bitmask pair. If not
38  *			given the default gpio_regmap_simple_xlate()
39  *			is used.
40  * @drvdata:		(Optional) Pointer to driver specific data which is
41  *			not used by gpio-remap but is provided "as is" to the
42  *			driver callback(s).
43  *
44  * The ->reg_mask_xlate translates a given base address and GPIO offset to
45  * register and mask pair. The base address is one of the given register
46  * base addresses in this structure.
47  *
48  * Although all register base addresses are marked as optional, there are
49  * several rules:
50  *     1. if you only have @reg_dat_base set, then it is input-only
51  *     2. if you only have @reg_set_base set, then it is output-only
52  *     3. if you have either @reg_dir_in_base or @reg_dir_out_base set, then
53  *        you have to set both @reg_dat_base and @reg_set_base
54  *     4. if you have @reg_set_base set, you may also set @reg_clr_base to have
55  *        two different registers for setting and clearing the output. This is
56  *        also valid for the output-only case.
57  *     5. @reg_dir_in_base and @reg_dir_out_base are exclusive; is there really
58  *        hardware which has redundant registers?
59  *
60  * Note: All base addresses may have the special value %GPIO_REGMAP_ADDR_ZERO
61  * which forces the address to the value 0.
62  */
63 struct gpio_regmap_config {
64 	struct device *parent;
65 	struct regmap *regmap;
66 	struct fwnode_handle *fwnode;
67 
68 	const char *label;
69 	int ngpio;
70 	const char *const *names;
71 
72 	unsigned int reg_dat_base;
73 	unsigned int reg_set_base;
74 	unsigned int reg_clr_base;
75 	unsigned int reg_dir_in_base;
76 	unsigned int reg_dir_out_base;
77 	int reg_stride;
78 	int ngpio_per_reg;
79 	struct irq_domain *irq_domain;
80 
81 	int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
82 			      unsigned int offset, unsigned int *reg,
83 			      unsigned int *mask);
84 
85 	void *drvdata;
86 };
87 
88 struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config);
89 void gpio_regmap_unregister(struct gpio_regmap *gpio);
90 struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
91 					      const struct gpio_regmap_config *config);
92 void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio);
93 
94 #endif /* _LINUX_GPIO_REGMAP_H */
95