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57e30e00 JN |
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 | #define TPS65219_GPIO_DIR_IN 1 | |
19 | #define TPS65219_GPIO_DIR_OUT 0 | |
20 | ||
21 | struct tps65219_gpio { | |
22 | struct gpio_chip gpio_chip; | |
23 | struct tps65219 *tps; | |
24 | }; | |
25 | ||
26 | static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) | |
27 | { | |
28 | struct tps65219_gpio *gpio = gpiochip_get_data(gc); | |
29 | int ret, val; | |
30 | ||
31 | if (offset != TPS65219_GPIO0_IDX) | |
32 | return GPIO_LINE_DIRECTION_OUT; | |
33 | ||
34 | ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val); | |
35 | if (ret) | |
36 | return ret; | |
37 | ||
38 | return !!(val & TPS65219_GPIO0_DIR_MASK); | |
39 | } | |
40 | ||
41 | static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset) | |
42 | { | |
43 | struct tps65219_gpio *gpio = gpiochip_get_data(gc); | |
44 | struct device *dev = gpio->tps->dev; | |
45 | int ret, val; | |
46 | ||
47 | if (offset != TPS65219_GPIO0_IDX) { | |
48 | dev_err(dev, "GPIO%d is output only, cannot get\n", offset); | |
49 | return -ENOTSUPP; | |
50 | } | |
51 | ||
52 | ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val); | |
53 | if (ret) | |
54 | return ret; | |
55 | ||
56 | ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK)); | |
57 | dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret); | |
58 | ||
59 | /* | |
60 | * Depending on NVM config, return an error if direction is output, otherwise the GPIO0 | |
61 | * status bit. | |
62 | */ | |
63 | ||
64 | if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT) | |
65 | return -ENOTSUPP; | |
66 | ||
67 | return ret; | |
68 | } | |
69 | ||
70 | static void tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value) | |
71 | { | |
72 | struct tps65219_gpio *gpio = gpiochip_get_data(gc); | |
73 | struct device *dev = gpio->tps->dev; | |
74 | int v, mask, bit; | |
75 | ||
76 | bit = (offset == TPS65219_GPIO0_IDX) ? TPS65219_GPIO0_OFFSET : offset - 1; | |
77 | ||
78 | mask = BIT(bit); | |
79 | v = value ? mask : 0; | |
80 | ||
81 | if (regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, mask, v)) | |
82 | dev_err(dev, "GPIO%d, set to value %d failed.\n", offset, value); | |
83 | } | |
84 | ||
85 | static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset, | |
86 | unsigned int direction) | |
87 | { | |
88 | struct tps65219_gpio *gpio = gpiochip_get_data(gc); | |
89 | struct device *dev = gpio->tps->dev; | |
90 | ||
91 | /* | |
92 | * Documentation is stating that GPIO0 direction must not be changed in Linux: | |
93 | * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE | |
94 | * state (prior to ON Request). | |
95 | * Set statically by NVM, changing direction in application can cause a hang. | |
96 | * Below can be used for test purpose only. | |
97 | */ | |
98 | ||
7dd1871e BG |
99 | #if 0 |
100 | int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, | |
101 | TPS65219_GPIO0_DIR_MASK, direction); | |
102 | if (ret) { | |
103 | dev_err(dev, | |
104 | "GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n", | |
105 | direction, offset); | |
106 | return ret; | |
57e30e00 | 107 | } |
7dd1871e | 108 | #endif |
57e30e00 JN |
109 | |
110 | dev_err(dev, | |
111 | "GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n", | |
112 | offset, direction); | |
113 | ||
114 | return -ENOTSUPP; | |
115 | } | |
116 | ||
117 | static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset) | |
118 | { | |
119 | struct tps65219_gpio *gpio = gpiochip_get_data(gc); | |
120 | struct device *dev = gpio->tps->dev; | |
121 | ||
122 | if (offset != TPS65219_GPIO0_IDX) { | |
123 | dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset); | |
124 | return -ENOTSUPP; | |
125 | } | |
126 | ||
127 | if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_IN) | |
128 | return 0; | |
129 | ||
130 | return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_IN); | |
131 | } | |
132 | ||
133 | static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value) | |
134 | { | |
135 | tps65219_gpio_set(gc, offset, value); | |
136 | if (offset != TPS65219_GPIO0_IDX) | |
137 | return 0; | |
138 | ||
139 | if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT) | |
140 | return 0; | |
141 | ||
142 | return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_OUT); | |
143 | } | |
144 | ||
145 | static const struct gpio_chip tps65219_template_chip = { | |
146 | .label = "tps65219-gpio", | |
147 | .owner = THIS_MODULE, | |
148 | .get_direction = tps65219_gpio_get_direction, | |
149 | .direction_input = tps65219_gpio_direction_input, | |
150 | .direction_output = tps65219_gpio_direction_output, | |
151 | .get = tps65219_gpio_get, | |
152 | .set = tps65219_gpio_set, | |
153 | .base = -1, | |
154 | .ngpio = 3, | |
155 | .can_sleep = true, | |
156 | }; | |
157 | ||
158 | static int tps65219_gpio_probe(struct platform_device *pdev) | |
159 | { | |
160 | struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent); | |
161 | struct tps65219_gpio *gpio; | |
162 | ||
163 | gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); | |
164 | if (!gpio) | |
165 | return -ENOMEM; | |
166 | ||
167 | gpio->tps = tps; | |
168 | gpio->gpio_chip = tps65219_template_chip; | |
169 | gpio->gpio_chip.parent = tps->dev; | |
170 | ||
171 | return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio); | |
172 | } | |
173 | ||
174 | static struct platform_driver tps65219_gpio_driver = { | |
175 | .driver = { | |
176 | .name = "tps65219-gpio", | |
177 | }, | |
178 | .probe = tps65219_gpio_probe, | |
179 | }; | |
180 | module_platform_driver(tps65219_gpio_driver); | |
181 | ||
182 | MODULE_ALIAS("platform:tps65219-gpio"); | |
183 | MODULE_AUTHOR("Jonathan Cormier <jcormier@criticallink.com>"); | |
184 | MODULE_DESCRIPTION("TPS65219 GPIO driver"); | |
185 | MODULE_LICENSE("GPL"); |