1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2018 ROHM Semiconductors
3
4 #include <linux/gpio/driver.h>
5 #include <linux/mfd/rohm-bd71828.h>
6 #include <linux/module.h>
7 #include <linux/platform_device.h>
8 #include <linux/regmap.h>
9
10 #define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off))
11 #define HALL_GPIO_OFFSET 3
12
13 struct bd71828_gpio {
14 struct rohm_regmap_dev chip;
15 struct gpio_chip gpio;
16 };
17
bd71828_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)18 static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset,
19 int value)
20 {
21 int ret;
22 struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
23 u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO;
24
25 /*
26 * The HALL input pin can only be used as input. If this is the pin
27 * we are dealing with - then we are done
28 */
29 if (offset == HALL_GPIO_OFFSET)
30 return;
31
32 ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
33 BD71828_GPIO_OUT_MASK, val);
34 if (ret)
35 dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value);
36 }
37
bd71828_gpio_get(struct gpio_chip * chip,unsigned int offset)38 static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset)
39 {
40 int ret;
41 unsigned int val;
42 struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
43
44 if (offset == HALL_GPIO_OFFSET)
45 ret = regmap_read(bdgpio->chip.regmap, BD71828_REG_IO_STAT,
46 &val);
47 else
48 ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset),
49 &val);
50 if (!ret)
51 ret = (val & BD71828_GPIO_OUT_MASK);
52
53 return ret;
54 }
55
bd71828_gpio_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)56 static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
57 unsigned long config)
58 {
59 struct bd71828_gpio *bdgpio = gpiochip_get_data(chip);
60
61 if (offset == HALL_GPIO_OFFSET)
62 return -ENOTSUPP;
63
64 switch (pinconf_to_config_param(config)) {
65 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
66 return regmap_update_bits(bdgpio->chip.regmap,
67 GPIO_OUT_REG(offset),
68 BD71828_GPIO_DRIVE_MASK,
69 BD71828_GPIO_OPEN_DRAIN);
70 case PIN_CONFIG_DRIVE_PUSH_PULL:
71 return regmap_update_bits(bdgpio->chip.regmap,
72 GPIO_OUT_REG(offset),
73 BD71828_GPIO_DRIVE_MASK,
74 BD71828_GPIO_PUSH_PULL);
75 default:
76 break;
77 }
78 return -ENOTSUPP;
79 }
80
bd71828_get_direction(struct gpio_chip * chip,unsigned int offset)81 static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset)
82 {
83 /*
84 * Pin usage is selected by OTP data. We can't read it runtime. Hence
85 * we trust that if the pin is not excluded by "gpio-reserved-ranges"
86 * the OTP configuration is set to OUT. (Other pins but HALL input pin
87 * on BD71828 can't really be used for general purpose input - input
88 * states are used for specific cases like regulator control or
89 * PMIC_ON_REQ.
90 */
91 if (offset == HALL_GPIO_OFFSET)
92 return GPIO_LINE_DIRECTION_IN;
93
94 return GPIO_LINE_DIRECTION_OUT;
95 }
96
bd71828_probe(struct platform_device * pdev)97 static int bd71828_probe(struct platform_device *pdev)
98 {
99 struct bd71828_gpio *bdgpio;
100 struct rohm_regmap_dev *bd71828;
101
102 bd71828 = dev_get_drvdata(pdev->dev.parent);
103 if (!bd71828) {
104 dev_err(&pdev->dev, "No MFD driver data\n");
105 return -EINVAL;
106 }
107
108 bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio),
109 GFP_KERNEL);
110 if (!bdgpio)
111 return -ENOMEM;
112
113 bdgpio->chip.dev = &pdev->dev;
114 bdgpio->gpio.parent = pdev->dev.parent;
115 bdgpio->gpio.label = "bd71828-gpio";
116 bdgpio->gpio.owner = THIS_MODULE;
117 bdgpio->gpio.get_direction = bd71828_get_direction;
118 bdgpio->gpio.set_config = bd71828_gpio_set_config;
119 bdgpio->gpio.can_sleep = true;
120 bdgpio->gpio.get = bd71828_gpio_get;
121 bdgpio->gpio.set = bd71828_gpio_set;
122 bdgpio->gpio.base = -1;
123
124 /*
125 * See if we need some implementation to mark some PINs as
126 * not controllable based on DT info or if core can handle
127 * "gpio-reserved-ranges" and exclude them from control
128 */
129 bdgpio->gpio.ngpio = 4;
130 bdgpio->gpio.of_node = pdev->dev.parent->of_node;
131 bdgpio->chip.regmap = bd71828->regmap;
132
133 return devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio,
134 bdgpio);
135 }
136
137 static struct platform_driver bd71828_gpio = {
138 .driver = {
139 .name = "bd71828-gpio"
140 },
141 .probe = bd71828_probe,
142 };
143
144 module_platform_driver(bd71828_gpio);
145
146 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
147 MODULE_DESCRIPTION("BD71828 voltage regulator driver");
148 MODULE_LICENSE("GPL");
149 MODULE_ALIAS("platform:bd71828-gpio");
150
