1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 ROHM Semiconductors
3 // gpio-bd70528.c ROHM BD70528MWV gpio driver
4
5 #include <linux/gpio/driver.h>
6 #include <linux/mfd/rohm-bd70528.h>
7 #include <linux/module.h>
8 #include <linux/platform_device.h>
9 #include <linux/regmap.h>
10
11 #define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + (offset) * 2)
12 #define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + (offset) * 2)
13
14 struct bd70528_gpio {
15 struct rohm_regmap_dev chip;
16 struct gpio_chip gpio;
17 };
18
bd70528_set_debounce(struct bd70528_gpio * bdgpio,unsigned int offset,unsigned int debounce)19 static int bd70528_set_debounce(struct bd70528_gpio *bdgpio,
20 unsigned int offset, unsigned int debounce)
21 {
22 u8 val;
23
24 switch (debounce) {
25 case 0:
26 val = BD70528_DEBOUNCE_DISABLE;
27 break;
28 case 1 ... 15000:
29 val = BD70528_DEBOUNCE_15MS;
30 break;
31 case 15001 ... 30000:
32 val = BD70528_DEBOUNCE_30MS;
33 break;
34 case 30001 ... 50000:
35 val = BD70528_DEBOUNCE_50MS;
36 break;
37 default:
38 dev_err(bdgpio->chip.dev,
39 "Invalid debounce value %u\n", debounce);
40 return -EINVAL;
41 }
42 return regmap_update_bits(bdgpio->chip.regmap, GPIO_IN_REG(offset),
43 BD70528_DEBOUNCE_MASK, val);
44 }
45
bd70528_get_direction(struct gpio_chip * chip,unsigned int offset)46 static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset)
47 {
48 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
49 int val, ret;
50
51 /* Do we need to do something to IRQs here? */
52 ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);
53 if (ret) {
54 dev_err(bdgpio->chip.dev, "Could not read gpio direction\n");
55 return ret;
56 }
57
58 return !(val & BD70528_GPIO_OUT_EN_MASK);
59 }
60
bd70528_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)61 static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
62 unsigned long config)
63 {
64 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
65
66 switch (pinconf_to_config_param(config)) {
67 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
68 return regmap_update_bits(bdgpio->chip.regmap,
69 GPIO_OUT_REG(offset),
70 BD70528_GPIO_DRIVE_MASK,
71 BD70528_GPIO_OPEN_DRAIN);
72 break;
73 case PIN_CONFIG_DRIVE_PUSH_PULL:
74 return regmap_update_bits(bdgpio->chip.regmap,
75 GPIO_OUT_REG(offset),
76 BD70528_GPIO_DRIVE_MASK,
77 BD70528_GPIO_PUSH_PULL);
78 break;
79 case PIN_CONFIG_INPUT_DEBOUNCE:
80 return bd70528_set_debounce(bdgpio, offset,
81 pinconf_to_config_argument(config));
82 break;
83 default:
84 break;
85 }
86 return -ENOTSUPP;
87 }
88
bd70528_direction_input(struct gpio_chip * chip,unsigned int offset)89 static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)
90 {
91 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
92
93 /* Do we need to do something to IRQs here? */
94 return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
95 BD70528_GPIO_OUT_EN_MASK,
96 BD70528_GPIO_OUT_DISABLE);
97 }
98
bd70528_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)99 static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,
100 int value)
101 {
102 int ret;
103 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
104 u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;
105
106 ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
107 BD70528_GPIO_OUT_MASK, val);
108 if (ret)
109 dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
110 }
111
bd70528_direction_output(struct gpio_chip * chip,unsigned int offset,int value)112 static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,
113 int value)
114 {
115 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
116
117 bd70528_gpio_set(chip, offset, value);
118 return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
119 BD70528_GPIO_OUT_EN_MASK,
120 BD70528_GPIO_OUT_ENABLE);
121 }
122
123 #define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset))
124
bd70528_gpio_get_o(struct bd70528_gpio * bdgpio,unsigned int offset)125 static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)
126 {
127 int ret;
128 unsigned int val;
129
130 ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);
131 if (!ret)
132 ret = !!(val & BD70528_GPIO_OUT_MASK);
133 else
134 dev_err(bdgpio->chip.dev, "GPIO (out) state read failed\n");
135
136 return ret;
137 }
138
bd70528_gpio_get_i(struct bd70528_gpio * bdgpio,unsigned int offset)139 static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)
140 {
141 unsigned int val;
142 int ret;
143
144 ret = regmap_read(bdgpio->chip.regmap, BD70528_REG_GPIO_STATE, &val);
145
146 if (!ret)
147 ret = !(val & GPIO_IN_STATE_MASK(offset));
148 else
149 dev_err(bdgpio->chip.dev, "GPIO (in) state read failed\n");
150
151 return ret;
152 }
153
bd70528_gpio_get(struct gpio_chip * chip,unsigned int offset)154 static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
155 {
156 int ret;
157 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
158
159 /*
160 * There is a race condition where someone might be changing the
161 * GPIO direction after we get it but before we read the value. But
162 * application design where GPIO direction may be changed just when
163 * we read GPIO value would be pointless as reader could not know
164 * whether the returned high/low state is caused by input or output.
165 * Or then there must be other ways to mitigate the issue. Thus
166 * locking would make no sense.
167 */
168 ret = bd70528_get_direction(chip, offset);
169 if (ret == 0)
170 ret = bd70528_gpio_get_o(bdgpio, offset);
171 else if (ret == 1)
172 ret = bd70528_gpio_get_i(bdgpio, offset);
173 else
174 dev_err(bdgpio->chip.dev, "failed to read GPIO direction\n");
175
176 return ret;
177 }
178
bd70528_probe(struct platform_device * pdev)179 static int bd70528_probe(struct platform_device *pdev)
180 {
181 struct bd70528_gpio *bdgpio;
182 struct rohm_regmap_dev *bd70528;
183 int ret;
184
185 bd70528 = dev_get_drvdata(pdev->dev.parent);
186 if (!bd70528) {
187 dev_err(&pdev->dev, "No MFD driver data\n");
188 return -EINVAL;
189 }
190
191 bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
192 GFP_KERNEL);
193 if (!bdgpio)
194 return -ENOMEM;
195 bdgpio->chip.dev = &pdev->dev;
196 bdgpio->gpio.parent = pdev->dev.parent;
197 bdgpio->gpio.label = "bd70528-gpio";
198 bdgpio->gpio.owner = THIS_MODULE;
199 bdgpio->gpio.get_direction = bd70528_get_direction;
200 bdgpio->gpio.direction_input = bd70528_direction_input;
201 bdgpio->gpio.direction_output = bd70528_direction_output;
202 bdgpio->gpio.set_config = bd70528_gpio_set_config;
203 bdgpio->gpio.can_sleep = true;
204 bdgpio->gpio.get = bd70528_gpio_get;
205 bdgpio->gpio.set = bd70528_gpio_set;
206 bdgpio->gpio.ngpio = 4;
207 bdgpio->gpio.base = -1;
208 #ifdef CONFIG_OF_GPIO
209 bdgpio->gpio.of_node = pdev->dev.parent->of_node;
210 #endif
211 bdgpio->chip.regmap = bd70528->regmap;
212
213 ret = devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
214 bdgpio);
215 if (ret)
216 dev_err(&pdev->dev, "gpio_init: Failed to add bd70528-gpio\n");
217
218 return ret;
219 }
220
221 static struct platform_driver bd70528_gpio = {
222 .driver = {
223 .name = "bd70528-gpio"
224 },
225 .probe = bd70528_probe,
226 };
227
228 module_platform_driver(bd70528_gpio);
229
230 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
231 MODULE_DESCRIPTION("BD70528 voltage regulator driver");
232 MODULE_LICENSE("GPL");
233