1 /*
2 * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
3 * Keerthy <j-keerthy@ti.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
10 * kind, whether expressed or implied; without even the implied warranty
11 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License version 2 for more details.
13 *
14 * Based on the TPS65218 driver
15 */
16
17 #include <linux/gpio/driver.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21
22 #include <linux/mfd/lp873x.h>
23
24 #define BITS_PER_GPO 0x4
25 #define LP873X_GPO_CTRL_OD 0x2
26
27 struct lp873x_gpio {
28 struct gpio_chip chip;
29 struct lp873x *lp873;
30 };
31
lp873x_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)32 static int lp873x_gpio_get_direction(struct gpio_chip *chip,
33 unsigned int offset)
34 {
35 /* This device is output only */
36 return GPIO_LINE_DIRECTION_OUT;
37 }
38
lp873x_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)39 static int lp873x_gpio_direction_input(struct gpio_chip *chip,
40 unsigned int offset)
41 {
42 /* This device is output only */
43 return -EINVAL;
44 }
45
lp873x_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)46 static int lp873x_gpio_direction_output(struct gpio_chip *chip,
47 unsigned int offset, int value)
48 {
49 struct lp873x_gpio *gpio = gpiochip_get_data(chip);
50
51 /* Set the initial value */
52 return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
53 BIT(offset * BITS_PER_GPO),
54 value ? BIT(offset * BITS_PER_GPO) : 0);
55 }
56
lp873x_gpio_get(struct gpio_chip * chip,unsigned int offset)57 static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
58 {
59 struct lp873x_gpio *gpio = gpiochip_get_data(chip);
60 int ret, val;
61
62 ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
63 if (ret < 0)
64 return ret;
65
66 return val & BIT(offset * BITS_PER_GPO);
67 }
68
lp873x_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)69 static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
70 int value)
71 {
72 struct lp873x_gpio *gpio = gpiochip_get_data(chip);
73
74 regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
75 BIT(offset * BITS_PER_GPO),
76 value ? BIT(offset * BITS_PER_GPO) : 0);
77 }
78
lp873x_gpio_request(struct gpio_chip * gc,unsigned int offset)79 static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
80 {
81 struct lp873x_gpio *gpio = gpiochip_get_data(gc);
82 int ret;
83
84 switch (offset) {
85 case 0:
86 /* No MUX Set up Needed for GPO */
87 break;
88 case 1:
89 /* Setup the CLKIN_PIN_SEL MUX to GPO2 */
90 ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
91 LP873X_CONFIG_CLKIN_PIN_SEL, 0);
92 if (ret)
93 return ret;
94
95 break;
96 default:
97 return -EINVAL;
98 }
99
100 return 0;
101 }
102
lp873x_gpio_set_config(struct gpio_chip * gc,unsigned offset,unsigned long config)103 static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
104 unsigned long config)
105 {
106 struct lp873x_gpio *gpio = gpiochip_get_data(gc);
107
108 switch (pinconf_to_config_param(config)) {
109 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
110 return regmap_update_bits(gpio->lp873->regmap,
111 LP873X_REG_GPO_CTRL,
112 BIT(offset * BITS_PER_GPO +
113 LP873X_GPO_CTRL_OD),
114 BIT(offset * BITS_PER_GPO +
115 LP873X_GPO_CTRL_OD));
116
117 case PIN_CONFIG_DRIVE_PUSH_PULL:
118 return regmap_update_bits(gpio->lp873->regmap,
119 LP873X_REG_GPO_CTRL,
120 BIT(offset * BITS_PER_GPO +
121 LP873X_GPO_CTRL_OD), 0);
122 default:
123 return -ENOTSUPP;
124 }
125 }
126
127 static const struct gpio_chip template_chip = {
128 .label = "lp873x-gpio",
129 .owner = THIS_MODULE,
130 .request = lp873x_gpio_request,
131 .get_direction = lp873x_gpio_get_direction,
132 .direction_input = lp873x_gpio_direction_input,
133 .direction_output = lp873x_gpio_direction_output,
134 .get = lp873x_gpio_get,
135 .set = lp873x_gpio_set,
136 .set_config = lp873x_gpio_set_config,
137 .base = -1,
138 .ngpio = 2,
139 .can_sleep = true,
140 };
141
lp873x_gpio_probe(struct platform_device * pdev)142 static int lp873x_gpio_probe(struct platform_device *pdev)
143 {
144 struct lp873x_gpio *gpio;
145 int ret;
146
147 gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
148 if (!gpio)
149 return -ENOMEM;
150
151 platform_set_drvdata(pdev, gpio);
152
153 gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
154 gpio->chip = template_chip;
155 gpio->chip.parent = gpio->lp873->dev;
156
157 ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
158 if (ret < 0) {
159 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
160 return ret;
161 }
162
163 return 0;
164 }
165
166 static const struct platform_device_id lp873x_gpio_id_table[] = {
167 { "lp873x-gpio", },
168 { /* sentinel */ }
169 };
170 MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
171
172 static struct platform_driver lp873x_gpio_driver = {
173 .driver = {
174 .name = "lp873x-gpio",
175 },
176 .probe = lp873x_gpio_probe,
177 .id_table = lp873x_gpio_id_table,
178 };
179 module_platform_driver(lp873x_gpio_driver);
180
181 MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
182 MODULE_DESCRIPTION("LP873X GPIO driver");
183 MODULE_LICENSE("GPL v2");
184