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f72f4b44 MR |
1 | /* |
2 | * AXP20x GPIO driver | |
3 | * | |
4 | * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2 of the License, or (at your | |
9 | * option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/bitops.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/gpio/driver.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/mfd/axp20x.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/regmap.h> | |
23 | #include <linux/slab.h> | |
24 | ||
25 | #define AXP20X_GPIO_FUNCTIONS 0x7 | |
26 | #define AXP20X_GPIO_FUNCTION_OUT_LOW 0 | |
27 | #define AXP20X_GPIO_FUNCTION_OUT_HIGH 1 | |
28 | #define AXP20X_GPIO_FUNCTION_INPUT 2 | |
29 | ||
30 | struct axp20x_gpio { | |
31 | struct gpio_chip chip; | |
32 | struct regmap *regmap; | |
33 | }; | |
34 | ||
35 | static int axp20x_gpio_get_reg(unsigned offset) | |
36 | { | |
37 | switch (offset) { | |
38 | case 0: | |
39 | return AXP20X_GPIO0_CTRL; | |
40 | case 1: | |
41 | return AXP20X_GPIO1_CTRL; | |
42 | case 2: | |
43 | return AXP20X_GPIO2_CTRL; | |
44 | } | |
45 | ||
46 | return -EINVAL; | |
47 | } | |
48 | ||
49 | static int axp20x_gpio_input(struct gpio_chip *chip, unsigned offset) | |
50 | { | |
51 | struct axp20x_gpio *gpio = gpiochip_get_data(chip); | |
52 | int reg; | |
53 | ||
54 | reg = axp20x_gpio_get_reg(offset); | |
55 | if (reg < 0) | |
56 | return reg; | |
57 | ||
58 | return regmap_update_bits(gpio->regmap, reg, | |
59 | AXP20X_GPIO_FUNCTIONS, | |
60 | AXP20X_GPIO_FUNCTION_INPUT); | |
61 | } | |
62 | ||
63 | static int axp20x_gpio_get(struct gpio_chip *chip, unsigned offset) | |
64 | { | |
65 | struct axp20x_gpio *gpio = gpiochip_get_data(chip); | |
66 | unsigned int val; | |
1d2b2ac0 | 67 | int ret; |
f72f4b44 | 68 | |
1d2b2ac0 | 69 | ret = regmap_read(gpio->regmap, AXP20X_GPIO20_SS, &val); |
f72f4b44 MR |
70 | if (ret) |
71 | return ret; | |
72 | ||
73 | return !!(val & BIT(offset + 4)); | |
74 | } | |
75 | ||
81d3753d MR |
76 | static int axp20x_gpio_get_direction(struct gpio_chip *chip, unsigned offset) |
77 | { | |
78 | struct axp20x_gpio *gpio = gpiochip_get_data(chip); | |
79 | unsigned int val; | |
80 | int reg, ret; | |
81 | ||
82 | reg = axp20x_gpio_get_reg(offset); | |
83 | if (reg < 0) | |
84 | return reg; | |
85 | ||
86 | ret = regmap_read(gpio->regmap, reg, &val); | |
87 | if (ret) | |
88 | return ret; | |
89 | ||
90 | /* | |
91 | * This shouldn't really happen if the pin is in use already, | |
92 | * or if it's not in use yet, it doesn't matter since we're | |
93 | * going to change the value soon anyway. Default to output. | |
94 | */ | |
95 | if ((val & AXP20X_GPIO_FUNCTIONS) > 2) | |
96 | return 0; | |
97 | ||
98 | /* | |
99 | * The GPIO directions are the three lowest values. | |
100 | * 2 is input, 0 and 1 are output | |
101 | */ | |
102 | return val & 2; | |
103 | } | |
104 | ||
f72f4b44 MR |
105 | static int axp20x_gpio_output(struct gpio_chip *chip, unsigned offset, |
106 | int value) | |
107 | { | |
108 | struct axp20x_gpio *gpio = gpiochip_get_data(chip); | |
109 | int reg; | |
110 | ||
111 | reg = axp20x_gpio_get_reg(offset); | |
112 | if (reg < 0) | |
113 | return reg; | |
114 | ||
115 | return regmap_update_bits(gpio->regmap, reg, | |
116 | AXP20X_GPIO_FUNCTIONS, | |
117 | value ? AXP20X_GPIO_FUNCTION_OUT_HIGH | |
118 | : AXP20X_GPIO_FUNCTION_OUT_LOW); | |
119 | } | |
120 | ||
121 | static void axp20x_gpio_set(struct gpio_chip *chip, unsigned offset, | |
122 | int value) | |
123 | { | |
124 | axp20x_gpio_output(chip, offset, value); | |
125 | } | |
126 | ||
127 | static int axp20x_gpio_probe(struct platform_device *pdev) | |
128 | { | |
129 | struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent); | |
130 | struct axp20x_gpio *gpio; | |
131 | int ret; | |
132 | ||
133 | if (!of_device_is_available(pdev->dev.of_node)) | |
134 | return -ENODEV; | |
135 | ||
136 | if (!axp20x) { | |
137 | dev_err(&pdev->dev, "Parent drvdata not set\n"); | |
138 | return -EINVAL; | |
139 | } | |
140 | ||
141 | gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); | |
142 | if (!gpio) | |
143 | return -ENOMEM; | |
144 | ||
145 | gpio->chip.base = -1; | |
146 | gpio->chip.can_sleep = true; | |
147 | gpio->chip.parent = &pdev->dev; | |
148 | gpio->chip.label = dev_name(&pdev->dev); | |
149 | gpio->chip.owner = THIS_MODULE; | |
150 | gpio->chip.get = axp20x_gpio_get; | |
81d3753d | 151 | gpio->chip.get_direction = axp20x_gpio_get_direction; |
f72f4b44 MR |
152 | gpio->chip.set = axp20x_gpio_set; |
153 | gpio->chip.direction_input = axp20x_gpio_input; | |
154 | gpio->chip.direction_output = axp20x_gpio_output; | |
155 | gpio->chip.ngpio = 3; | |
156 | ||
157 | gpio->regmap = axp20x->regmap; | |
158 | ||
159 | ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio); | |
160 | if (ret) { | |
161 | dev_err(&pdev->dev, "Failed to register GPIO chip\n"); | |
162 | return ret; | |
163 | } | |
164 | ||
165 | dev_info(&pdev->dev, "AXP209 GPIO driver loaded\n"); | |
166 | ||
167 | return 0; | |
168 | } | |
169 | ||
170 | static const struct of_device_id axp20x_gpio_match[] = { | |
171 | { .compatible = "x-powers,axp209-gpio" }, | |
172 | { } | |
173 | }; | |
174 | MODULE_DEVICE_TABLE(of, axp20x_gpio_match); | |
175 | ||
176 | static struct platform_driver axp20x_gpio_driver = { | |
177 | .probe = axp20x_gpio_probe, | |
178 | .driver = { | |
179 | .name = "axp20x-gpio", | |
180 | .of_match_table = axp20x_gpio_match, | |
181 | }, | |
182 | }; | |
183 | ||
184 | module_platform_driver(axp20x_gpio_driver); | |
185 | ||
186 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); | |
187 | MODULE_DESCRIPTION("AXP20x PMIC GPIO driver"); | |
188 | MODULE_LICENSE("GPL"); |