diff options
Diffstat (limited to 'arch/arm/plat-s3c/gpio.c')
-rw-r--r-- | arch/arm/plat-s3c/gpio.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/gpio.c b/arch/arm/plat-s3c/gpio.c new file mode 100644 index 000000000000..d71dd6d9ce5c --- /dev/null +++ b/arch/arm/plat-s3c/gpio.c | |||
@@ -0,0 +1,147 @@ | |||
1 | /* linux/arch/arm/plat-s3c/gpio.c | ||
2 | * | ||
3 | * Copyright 2008 Simtec Electronics | ||
4 | * Ben Dooks <ben@simtec.co.uk> | ||
5 | * http://armlinux.simtec.co.uk/ | ||
6 | * | ||
7 | * S3C series GPIO core | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or modify | ||
10 | * it under the terms of the GNU General Public License version 2 as | ||
11 | * published by the Free Software Foundation. | ||
12 | */ | ||
13 | |||
14 | #include <linux/kernel.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/io.h> | ||
17 | #include <linux/gpio.h> | ||
18 | |||
19 | #include <plat/gpio-core.h> | ||
20 | |||
21 | #ifdef CONFIG_S3C_GPIO_TRACK | ||
22 | struct s3c_gpio_chip *s3c_gpios[S3C_GPIO_END]; | ||
23 | |||
24 | static __init void s3c_gpiolib_track(struct s3c_gpio_chip *chip) | ||
25 | { | ||
26 | unsigned int gpn; | ||
27 | int i; | ||
28 | |||
29 | gpn = chip->chip.base; | ||
30 | for (i = 0; i < chip->chip.ngpio; i++, gpn++) { | ||
31 | BUG_ON(gpn > ARRAY_SIZE(s3c_gpios)); | ||
32 | s3c_gpios[gpn] = chip; | ||
33 | } | ||
34 | } | ||
35 | #endif /* CONFIG_S3C_GPIO_TRACK */ | ||
36 | |||
37 | /* Default routines for controlling GPIO, based on the original S3C24XX | ||
38 | * GPIO functions which deal with the case where each gpio bank of the | ||
39 | * chip is as following: | ||
40 | * | ||
41 | * base + 0x00: Control register, 2 bits per gpio | ||
42 | * gpio n: 2 bits starting at (2*n) | ||
43 | * 00 = input, 01 = output, others mean special-function | ||
44 | * base + 0x04: Data register, 1 bit per gpio | ||
45 | * bit n: data bit n | ||
46 | */ | ||
47 | |||
48 | static int s3c_gpiolib_input(struct gpio_chip *chip, unsigned offset) | ||
49 | { | ||
50 | struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); | ||
51 | void __iomem *base = ourchip->base; | ||
52 | unsigned long flags; | ||
53 | unsigned long con; | ||
54 | |||
55 | local_irq_save(flags); | ||
56 | |||
57 | con = __raw_readl(base + 0x00); | ||
58 | con &= ~(3 << (offset * 2)); | ||
59 | |||
60 | __raw_writel(con, base + 0x00); | ||
61 | |||
62 | local_irq_restore(flags); | ||
63 | return 0; | ||
64 | } | ||
65 | |||
66 | static int s3c_gpiolib_output(struct gpio_chip *chip, | ||
67 | unsigned offset, int value) | ||
68 | { | ||
69 | struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); | ||
70 | void __iomem *base = ourchip->base; | ||
71 | unsigned long flags; | ||
72 | unsigned long dat; | ||
73 | unsigned long con; | ||
74 | |||
75 | local_irq_save(flags); | ||
76 | |||
77 | dat = __raw_readl(base + 0x04); | ||
78 | dat &= ~(1 << offset); | ||
79 | if (value) | ||
80 | dat |= 1 << offset; | ||
81 | __raw_writel(dat, base + 0x04); | ||
82 | |||
83 | con = __raw_readl(base + 0x00); | ||
84 | con &= ~(3 << (offset * 2)); | ||
85 | con |= 1 << (offset * 2); | ||
86 | |||
87 | __raw_writel(con, base + 0x00); | ||
88 | __raw_writel(dat, base + 0x04); | ||
89 | |||
90 | local_irq_restore(flags); | ||
91 | return 0; | ||
92 | } | ||
93 | |||
94 | static void s3c_gpiolib_set(struct gpio_chip *chip, | ||
95 | unsigned offset, int value) | ||
96 | { | ||
97 | struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); | ||
98 | void __iomem *base = ourchip->base; | ||
99 | unsigned long flags; | ||
100 | unsigned long dat; | ||
101 | |||
102 | local_irq_save(flags); | ||
103 | |||
104 | dat = __raw_readl(base + 0x04); | ||
105 | dat &= ~(1 << offset); | ||
106 | if (value) | ||
107 | dat |= 1 << offset; | ||
108 | __raw_writel(dat, base + 0x04); | ||
109 | |||
110 | local_irq_restore(flags); | ||
111 | } | ||
112 | |||
113 | static int s3c_gpiolib_get(struct gpio_chip *chip, unsigned offset) | ||
114 | { | ||
115 | struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip); | ||
116 | unsigned long val; | ||
117 | |||
118 | val = __raw_readl(ourchip->base + 0x04); | ||
119 | val >>= offset; | ||
120 | val &= 1; | ||
121 | |||
122 | return val; | ||
123 | } | ||
124 | |||
125 | __init void s3c_gpiolib_add(struct s3c_gpio_chip *chip) | ||
126 | { | ||
127 | struct gpio_chip *gc = &chip->chip; | ||
128 | int ret; | ||
129 | |||
130 | BUG_ON(!chip->base); | ||
131 | BUG_ON(!gc->label); | ||
132 | BUG_ON(!gc->ngpio); | ||
133 | |||
134 | if (!gc->direction_input) | ||
135 | gc->direction_input = s3c_gpiolib_input; | ||
136 | if (!gc->direction_output) | ||
137 | gc->direction_output = s3c_gpiolib_output; | ||
138 | if (!gc->set) | ||
139 | gc->set = s3c_gpiolib_set; | ||
140 | if (!gc->get) | ||
141 | gc->get = s3c_gpiolib_get; | ||
142 | |||
143 | /* gpiochip_add() prints own failure message on error. */ | ||
144 | ret = gpiochip_add(gc); | ||
145 | if (ret >= 0) | ||
146 | s3c_gpiolib_track(chip); | ||
147 | } | ||