1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright 2008 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>
6 *
7 * S3C Platform - GPIO core
8 */
9
10 #ifndef __PLAT_SAMSUNG_GPIO_CORE_H
11 #define __PLAT_SAMSUNG_GPIO_CORE_H
12
13 /* Bring in machine-local definitions, especially S3C_GPIO_END */
14 #include <mach/gpio-samsung.h>
15 #include <linux/gpio/driver.h>
16
17 #define GPIOCON_OFF (0x00)
18 #define GPIODAT_OFF (0x04)
19
20 #define con_4bit_shift(__off) ((__off) * 4)
21
22 /* Define the core gpiolib support functions that the s3c platforms may
23 * need to extend or change depending on the hardware and the s3c chip
24 * selected at build or found at run time.
25 *
26 * These definitions are not intended for driver inclusion, there is
27 * nothing here that should not live outside the platform and core
28 * specific code.
29 */
30
31 struct samsung_gpio_chip;
32
33 /**
34 * struct samsung_gpio_pm - power management (suspend/resume) information
35 * @save: Routine to save the state of the GPIO block
36 * @resume: Routine to resume the GPIO block.
37 */
38 struct samsung_gpio_pm {
39 void (*save)(struct samsung_gpio_chip *chip);
40 void (*resume)(struct samsung_gpio_chip *chip);
41 };
42
43 struct samsung_gpio_cfg;
44
45 /**
46 * struct samsung_gpio_chip - wrapper for specific implementation of gpio
47 * @chip: The chip structure to be exported via gpiolib.
48 * @base: The base pointer to the gpio configuration registers.
49 * @group: The group register number for gpio interrupt support.
50 * @irq_base: The base irq number.
51 * @config: special function and pull-resistor control information.
52 * @lock: Lock for exclusive access to this gpio bank.
53 * @pm_save: Save information for suspend/resume support.
54 * @bitmap_gpio_int: Bitmap for representing GPIO interrupt or not.
55 *
56 * This wrapper provides the necessary information for the Samsung
57 * specific gpios being registered with gpiolib.
58 *
59 * The lock protects each gpio bank from multiple access of the shared
60 * configuration registers, or from reading of data whilst another thread
61 * is writing to the register set.
62 *
63 * Each chip has its own lock to avoid any contention between different
64 * CPU cores trying to get one lock for different GPIO banks, where each
65 * bank of GPIO has its own register space and configuration registers.
66 */
67 struct samsung_gpio_chip {
68 struct gpio_chip chip;
69 struct samsung_gpio_cfg *config;
70 struct samsung_gpio_pm *pm;
71 void __iomem *base;
72 int irq_base;
73 int group;
74 spinlock_t lock;
75 #ifdef CONFIG_PM
76 u32 pm_save[4];
77 #endif
78 u32 bitmap_gpio_int;
79 };
80
81 static inline struct samsung_gpio_chip *to_samsung_gpio(struct gpio_chip *gpc)
82 {
83 return container_of(gpc, struct samsung_gpio_chip, chip);
84 }
85
86 /**
87 * samsung_gpiolib_to_irq - convert gpio pin to irq number
88 * @chip: The gpio chip that the pin belongs to.
89 * @offset: The offset of the pin in the chip.
90 *
91 * This helper returns the irq number calculated from the chip->irq_base and
92 * the provided offset.
93 */
94 extern int samsung_gpiolib_to_irq(struct gpio_chip *chip, unsigned int offset);
95
96 /* exported for core SoC support to change */
97 extern struct samsung_gpio_cfg s3c24xx_gpiocfg_default;
98
99 #ifdef CONFIG_S3C_GPIO_TRACK
100 extern struct samsung_gpio_chip *s3c_gpios[S3C_GPIO_END];
101
102 static inline struct samsung_gpio_chip *samsung_gpiolib_getchip(unsigned int chip)
103 {
104 return (chip < S3C_GPIO_END) ? s3c_gpios[chip] : NULL;
105 }
106 #else
107 /* machine specific code should provide samsung_gpiolib_getchip */
108
109 extern struct samsung_gpio_chip s3c24xx_gpios[];
110
111 static inline struct samsung_gpio_chip *samsung_gpiolib_getchip(unsigned int pin)
112 {
113 struct samsung_gpio_chip *chip;
114
115 if (pin > S3C_GPIO_END)
116 return NULL;
117
118 chip = &s3c24xx_gpios[pin/32];
119 return ((pin - chip->chip.base) < chip->chip.ngpio) ? chip : NULL;
120 }
121
122 static inline void s3c_gpiolib_track(struct samsung_gpio_chip *chip) { }
123 #endif
124
125 #ifdef CONFIG_PM
126 extern struct samsung_gpio_pm samsung_gpio_pm_1bit;
127 extern struct samsung_gpio_pm samsung_gpio_pm_2bit;
128 extern struct samsung_gpio_pm samsung_gpio_pm_4bit;
129 #define __gpio_pm(x) x
130 #else
131 #define samsung_gpio_pm_1bit NULL
132 #define samsung_gpio_pm_2bit NULL
133 #define samsung_gpio_pm_4bit NULL
134 #define __gpio_pm(x) NULL
135
136 #endif /* CONFIG_PM */
137
138 /* locking wrappers to deal with multiple access to the same gpio bank */
139 #define samsung_gpio_lock(_oc, _fl) spin_lock_irqsave(&(_oc)->lock, _fl)
140 #define samsung_gpio_unlock(_oc, _fl) spin_unlock_irqrestore(&(_oc)->lock, _fl)
141
142 #endif /* __PLAT_SAMSUNG_GPIO_CORE_H */