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 if (val & BD70528_GPIO_OUT_EN_MASK)
58 return GPIO_LINE_DIRECTION_OUT;
59
60 return GPIO_LINE_DIRECTION_IN;
61 }
62
bd70528_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)63 static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
64 unsigned long config)
65 {
66 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
67
68 switch (pinconf_to_config_param(config)) {
69 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
70 return regmap_update_bits(bdgpio->chip.regmap,
71 GPIO_OUT_REG(offset),
72 BD70528_GPIO_DRIVE_MASK,
73 BD70528_GPIO_OPEN_DRAIN);
74 break;
75 case PIN_CONFIG_DRIVE_PUSH_PULL:
76 return regmap_update_bits(bdgpio->chip.regmap,
77 GPIO_OUT_REG(offset),
78 BD70528_GPIO_DRIVE_MASK,
79 BD70528_GPIO_PUSH_PULL);
80 break;
81 case PIN_CONFIG_INPUT_DEBOUNCE:
82 return bd70528_set_debounce(bdgpio, offset,
83 pinconf_to_config_argument(config));
84 break;
85 default:
86 break;
87 }
88 return -ENOTSUPP;
89 }
90
bd70528_direction_input(struct gpio_chip * chip,unsigned int offset)91 static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)
92 {
93 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
94
95 /* Do we need to do something to IRQs here? */
96 return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
97 BD70528_GPIO_OUT_EN_MASK,
98 BD70528_GPIO_OUT_DISABLE);
99 }
100
bd70528_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)101 static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,
102 int value)
103 {
104 int ret;
105 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
106 u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;
107
108 ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
109 BD70528_GPIO_OUT_MASK, val);
110 if (ret)
111 dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
112 }
113
bd70528_direction_output(struct gpio_chip * chip,unsigned int offset,int value)114 static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,
115 int value)
116 {
117 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
118
119 bd70528_gpio_set(chip, offset, value);
120 return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
121 BD70528_GPIO_OUT_EN_MASK,
122 BD70528_GPIO_OUT_ENABLE);
123 }
124
125 #define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset))
126
bd70528_gpio_get_o(struct bd70528_gpio * bdgpio,unsigned int offset)127 static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)
128 {
129 int ret;
130 unsigned int val;
131
132 ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val);
133 if (!ret)
134 ret = !!(val & BD70528_GPIO_OUT_MASK);
135 else
136 dev_err(bdgpio->chip.dev, "GPIO (out) state read failed\n");
137
138 return ret;
139 }
140
bd70528_gpio_get_i(struct bd70528_gpio * bdgpio,unsigned int offset)141 static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)
142 {
143 unsigned int val;
144 int ret;
145
146 ret = regmap_read(bdgpio->chip.regmap, BD70528_REG_GPIO_STATE, &val);
147
148 if (!ret)
149 ret = !(val & GPIO_IN_STATE_MASK(offset));
150 else
151 dev_err(bdgpio->chip.dev, "GPIO (in) state read failed\n");
152
153 return ret;
154 }
155
bd70528_gpio_get(struct gpio_chip * chip,unsigned int offset)156 static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
157 {
158 int ret;
159 struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
160
161 /*
162 * There is a race condition where someone might be changing the
163 * GPIO direction after we get it but before we read the value. But
164 * application design where GPIO direction may be changed just when
165 * we read GPIO value would be pointless as reader could not know
166 * whether the returned high/low state is caused by input or output.
167 * Or then there must be other ways to mitigate the issue. Thus
168 * locking would make no sense.
169 */
170 ret = bd70528_get_direction(chip, offset);
171 if (ret == GPIO_LINE_DIRECTION_OUT)
172 ret = bd70528_gpio_get_o(bdgpio, offset);
173 else if (ret == GPIO_LINE_DIRECTION_IN)
174 ret = bd70528_gpio_get_i(bdgpio, offset);
175 else
176 dev_err(bdgpio->chip.dev, "failed to read GPIO direction\n");
177
178 return ret;
179 }
180
bd70528_probe(struct platform_device * pdev)181 static int bd70528_probe(struct platform_device *pdev)
182 {
183 struct bd70528_gpio *bdgpio;
184 struct rohm_regmap_dev *bd70528;
185 int ret;
186
187 bd70528 = dev_get_drvdata(pdev->dev.parent);
188 if (!bd70528) {
189 dev_err(&pdev->dev, "No MFD driver data\n");
190 return -EINVAL;
191 }
192
193 bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
194 GFP_KERNEL);
195 if (!bdgpio)
196 return -ENOMEM;
197 bdgpio->chip.dev = &pdev->dev;
198 bdgpio->gpio.parent = pdev->dev.parent;
199 bdgpio->gpio.label = "bd70528-gpio";
200 bdgpio->gpio.owner = THIS_MODULE;
201 bdgpio->gpio.get_direction = bd70528_get_direction;
202 bdgpio->gpio.direction_input = bd70528_direction_input;
203 bdgpio->gpio.direction_output = bd70528_direction_output;
204 bdgpio->gpio.set_config = bd70528_gpio_set_config;
205 bdgpio->gpio.can_sleep = true;
206 bdgpio->gpio.get = bd70528_gpio_get;
207 bdgpio->gpio.set = bd70528_gpio_set;
208 bdgpio->gpio.ngpio = 4;
209 bdgpio->gpio.base = -1;
210 #ifdef CONFIG_OF_GPIO
211 bdgpio->gpio.of_node = pdev->dev.parent->of_node;
212 #endif
213 bdgpio->chip.regmap = bd70528->regmap;
214
215 ret = devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
216 bdgpio);
217 if (ret)
218 dev_err(&pdev->dev, "gpio_init: Failed to add bd70528-gpio\n");
219
220 return ret;
221 }
222
223 static struct platform_driver bd70528_gpio = {
224 .driver = {
225 .name = "bd70528-gpio"
226 },
227 .probe = bd70528_probe,
228 };
229
230 module_platform_driver(bd70528_gpio);
231
232 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
233 MODULE_DESCRIPTION("BD70528 voltage regulator driver");
234 MODULE_LICENSE("GPL");
235 MODULE_ALIAS("platform:bd70528-gpio");
236
