1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * GPIO driver for TI TPS65219 PMICs
4 *
5 * Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
6 */
7
8 #include <linux/bits.h>
9 #include <linux/gpio/driver.h>
10 #include <linux/mfd/tps65219.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14
15 #define TPS65219_GPIO0_DIR_MASK BIT(3)
16 #define TPS65219_GPIO0_OFFSET 2
17 #define TPS65219_GPIO0_IDX 0
18
19 struct tps65219_gpio {
20 struct gpio_chip gpio_chip;
21 struct tps65219 *tps;
22 };
23
tps65219_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)24 static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
25 {
26 struct tps65219_gpio *gpio = gpiochip_get_data(gc);
27 int ret, val;
28
29 if (offset != TPS65219_GPIO0_IDX)
30 return GPIO_LINE_DIRECTION_OUT;
31
32 ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
33 if (ret)
34 return ret;
35
36 return !!(val & TPS65219_GPIO0_DIR_MASK);
37 }
38
tps65219_gpio_get(struct gpio_chip * gc,unsigned int offset)39 static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset)
40 {
41 struct tps65219_gpio *gpio = gpiochip_get_data(gc);
42 struct device *dev = gpio->tps->dev;
43 int ret, val;
44
45 if (offset != TPS65219_GPIO0_IDX) {
46 dev_err(dev, "GPIO%d is output only, cannot get\n", offset);
47 return -ENOTSUPP;
48 }
49
50 ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val);
51 if (ret)
52 return ret;
53
54 ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK));
55 dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret);
56
57 /*
58 * Depending on NVM config, return an error if direction is output, otherwise the GPIO0
59 * status bit.
60 */
61
62 if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_OUT)
63 return -ENOTSUPP;
64
65 return ret;
66 }
67
tps65219_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)68 static void tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
69 {
70 struct tps65219_gpio *gpio = gpiochip_get_data(gc);
71 struct device *dev = gpio->tps->dev;
72 int v, mask, bit;
73
74 bit = (offset == TPS65219_GPIO0_IDX) ? TPS65219_GPIO0_OFFSET : offset - 1;
75
76 mask = BIT(bit);
77 v = value ? mask : 0;
78
79 if (regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, mask, v))
80 dev_err(dev, "GPIO%d, set to value %d failed.\n", offset, value);
81 }
82
tps65219_gpio_change_direction(struct gpio_chip * gc,unsigned int offset,unsigned int direction)83 static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
84 unsigned int direction)
85 {
86 struct tps65219_gpio *gpio = gpiochip_get_data(gc);
87 struct device *dev = gpio->tps->dev;
88
89 /*
90 * Documentation is stating that GPIO0 direction must not be changed in Linux:
91 * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE
92 * state (prior to ON Request).
93 * Set statically by NVM, changing direction in application can cause a hang.
94 * Below can be used for test purpose only.
95 */
96
97 #if 0
98 int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
99 TPS65219_GPIO0_DIR_MASK, direction);
100 if (ret) {
101 dev_err(dev,
102 "GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n",
103 direction, offset);
104 return ret;
105 }
106 #endif
107
108 dev_err(dev,
109 "GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
110 offset, direction);
111
112 return -ENOTSUPP;
113 }
114
tps65219_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)115 static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
116 {
117 struct tps65219_gpio *gpio = gpiochip_get_data(gc);
118 struct device *dev = gpio->tps->dev;
119
120 if (offset != TPS65219_GPIO0_IDX) {
121 dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset);
122 return -ENOTSUPP;
123 }
124
125 if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_IN)
126 return 0;
127
128 return tps65219_gpio_change_direction(gc, offset, GPIO_LINE_DIRECTION_IN);
129 }
130
tps65219_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int value)131 static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
132 {
133 tps65219_gpio_set(gc, offset, value);
134 if (offset != TPS65219_GPIO0_IDX)
135 return 0;
136
137 if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_OUT)
138 return 0;
139
140 return tps65219_gpio_change_direction(gc, offset, GPIO_LINE_DIRECTION_OUT);
141 }
142
143 static const struct gpio_chip tps65219_template_chip = {
144 .label = "tps65219-gpio",
145 .owner = THIS_MODULE,
146 .get_direction = tps65219_gpio_get_direction,
147 .direction_input = tps65219_gpio_direction_input,
148 .direction_output = tps65219_gpio_direction_output,
149 .get = tps65219_gpio_get,
150 .set = tps65219_gpio_set,
151 .base = -1,
152 .ngpio = 3,
153 .can_sleep = true,
154 };
155
tps65219_gpio_probe(struct platform_device * pdev)156 static int tps65219_gpio_probe(struct platform_device *pdev)
157 {
158 struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
159 struct tps65219_gpio *gpio;
160
161 gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
162 if (!gpio)
163 return -ENOMEM;
164
165 gpio->tps = tps;
166 gpio->gpio_chip = tps65219_template_chip;
167 gpio->gpio_chip.parent = tps->dev;
168
169 return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio);
170 }
171
172 static struct platform_driver tps65219_gpio_driver = {
173 .driver = {
174 .name = "tps65219-gpio",
175 },
176 .probe = tps65219_gpio_probe,
177 };
178 module_platform_driver(tps65219_gpio_driver);
179
180 MODULE_ALIAS("platform:tps65219-gpio");
181 MODULE_AUTHOR("Jonathan Cormier <[email protected]>");
182 MODULE_DESCRIPTION("TPS65219 GPIO driver");
183 MODULE_LICENSE("GPL");
184