1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | // |
3 | // Functions to access SY3686A power management chip voltages |
4 | // |
5 | // Copyright (C) 2019 reMarkable AS - http://www.remarkable.com/ |
6 | // |
7 | // Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com> |
8 | // Alistair Francis <alistair@alistair23.me> |
9 | |
10 | #include <linux/gpio/consumer.h> |
11 | #include <linux/i2c.h> |
12 | #include <linux/mfd/sy7636a.h> |
13 | #include <linux/module.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/regulator/driver.h> |
16 | #include <linux/regulator/machine.h> |
17 | #include <linux/regmap.h> |
18 | |
19 | struct sy7636a_data { |
20 | struct regmap *regmap; |
21 | struct gpio_desc *pgood_gpio; |
22 | }; |
23 | |
24 | static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev) |
25 | { |
26 | int ret; |
27 | unsigned int val, val_h; |
28 | |
29 | ret = regmap_read(map: rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, val: &val); |
30 | if (ret) |
31 | return ret; |
32 | |
33 | ret = regmap_read(map: rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, val: &val_h); |
34 | if (ret) |
35 | return ret; |
36 | |
37 | val |= (val_h << VCOM_ADJUST_CTRL_SHIFT); |
38 | |
39 | return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL; |
40 | } |
41 | |
42 | static int sy7636a_get_status(struct regulator_dev *rdev) |
43 | { |
44 | struct sy7636a_data *data = dev_get_drvdata(dev: rdev->dev.parent); |
45 | int ret = 0; |
46 | |
47 | ret = gpiod_get_value_cansleep(desc: data->pgood_gpio); |
48 | if (ret < 0) |
49 | dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n" , ret); |
50 | |
51 | return ret; |
52 | } |
53 | |
54 | static const struct regulator_ops sy7636a_vcom_volt_ops = { |
55 | .get_voltage = sy7636a_get_vcom_voltage_op, |
56 | .enable = regulator_enable_regmap, |
57 | .disable = regulator_disable_regmap, |
58 | .is_enabled = regulator_is_enabled_regmap, |
59 | .get_status = sy7636a_get_status, |
60 | }; |
61 | |
62 | static const struct regulator_desc desc = { |
63 | .name = "vcom" , |
64 | .id = 0, |
65 | .ops = &sy7636a_vcom_volt_ops, |
66 | .type = REGULATOR_VOLTAGE, |
67 | .owner = THIS_MODULE, |
68 | .enable_reg = SY7636A_REG_OPERATION_MODE_CRL, |
69 | .enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF, |
70 | .regulators_node = of_match_ptr("regulators" ), |
71 | .of_match = of_match_ptr("vcom" ), |
72 | }; |
73 | |
74 | static int sy7636a_regulator_probe(struct platform_device *pdev) |
75 | { |
76 | struct regmap *regmap = dev_get_regmap(dev: pdev->dev.parent, NULL); |
77 | struct regulator_config config = { }; |
78 | struct regulator_dev *rdev; |
79 | struct gpio_desc *gdp; |
80 | struct sy7636a_data *data; |
81 | int ret; |
82 | |
83 | if (!regmap) |
84 | return -EPROBE_DEFER; |
85 | |
86 | gdp = devm_gpiod_get(dev: pdev->dev.parent, con_id: "epd-pwr-good" , flags: GPIOD_IN); |
87 | if (IS_ERR(ptr: gdp)) { |
88 | dev_err(pdev->dev.parent, "Power good GPIO fault %ld\n" , PTR_ERR(gdp)); |
89 | return PTR_ERR(ptr: gdp); |
90 | } |
91 | |
92 | data = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct sy7636a_data), GFP_KERNEL); |
93 | if (!data) |
94 | return -ENOMEM; |
95 | |
96 | data->regmap = regmap; |
97 | data->pgood_gpio = gdp; |
98 | |
99 | platform_set_drvdata(pdev, data); |
100 | |
101 | ret = regmap_write(map: regmap, SY7636A_REG_POWER_ON_DELAY_TIME, val: 0x0); |
102 | if (ret) { |
103 | dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n" , ret); |
104 | return ret; |
105 | } |
106 | |
107 | config.dev = &pdev->dev; |
108 | config.dev->of_node = pdev->dev.parent->of_node; |
109 | config.regmap = regmap; |
110 | |
111 | rdev = devm_regulator_register(dev: &pdev->dev, regulator_desc: &desc, config: &config); |
112 | if (IS_ERR(ptr: rdev)) { |
113 | dev_err(pdev->dev.parent, "Failed to register %s regulator\n" , |
114 | pdev->name); |
115 | return PTR_ERR(ptr: rdev); |
116 | } |
117 | |
118 | return 0; |
119 | } |
120 | |
121 | static const struct platform_device_id sy7636a_regulator_id_table[] = { |
122 | { "sy7636a-regulator" , }, |
123 | { } |
124 | }; |
125 | MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table); |
126 | |
127 | static struct platform_driver sy7636a_regulator_driver = { |
128 | .driver = { |
129 | .name = "sy7636a-regulator" , |
130 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
131 | }, |
132 | .probe = sy7636a_regulator_probe, |
133 | .id_table = sy7636a_regulator_id_table, |
134 | }; |
135 | module_platform_driver(sy7636a_regulator_driver); |
136 | |
137 | MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>" ); |
138 | MODULE_DESCRIPTION("SY7636A voltage regulator driver" ); |
139 | MODULE_LICENSE("GPL v2" ); |
140 | |