1 // SPDX-License-Identifier: GPL-2.0+
3 // Functions to access SY3686A power management chip voltages
5 // Copyright (C) 2019 reMarkable AS - http://www.remarkable.com/
7 // Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
8 // Alistair Francis <alistair@alistair23.me>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/mfd/sy7636a.h>
17 struct regmap *regmap;
18 struct gpio_desc *pgood_gpio;
21 static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
24 unsigned int val, val_h;
26 ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
30 ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
34 val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
36 return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
39 static int sy7636a_get_status(struct regulator_dev *rdev)
41 struct sy7636a_data *data = dev_get_drvdata(rdev->dev.parent);
44 ret = gpiod_get_value_cansleep(data->pgood_gpio);
46 dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", ret);
51 static const struct regulator_ops sy7636a_vcom_volt_ops = {
52 .get_voltage = sy7636a_get_vcom_voltage_op,
53 .enable = regulator_enable_regmap,
54 .disable = regulator_disable_regmap,
55 .is_enabled = regulator_is_enabled_regmap,
56 .get_status = sy7636a_get_status,
59 static const struct regulator_desc desc = {
62 .ops = &sy7636a_vcom_volt_ops,
63 .type = REGULATOR_VOLTAGE,
65 .enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
66 .enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
67 .regulators_node = of_match_ptr("regulators"),
68 .of_match = of_match_ptr("vcom"),
71 static int sy7636a_regulator_probe(struct platform_device *pdev)
73 struct regmap *regmap = dev_get_drvdata(pdev->dev.parent);
74 struct regulator_config config = { };
75 struct regulator_dev *rdev;
76 struct gpio_desc *gdp;
77 struct sy7636a_data *data;
83 gdp = devm_gpiod_get(pdev->dev.parent, "epd-pwr-good", GPIOD_IN);
85 dev_err(pdev->dev.parent, "Power good GPIO fault %ld\n", PTR_ERR(gdp));
89 data = devm_kzalloc(&pdev->dev, sizeof(struct sy7636a_data), GFP_KERNEL);
93 data->regmap = regmap;
94 data->pgood_gpio = gdp;
96 platform_set_drvdata(pdev, data);
98 ret = regmap_write(regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
100 dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n", ret);
104 config.dev = &pdev->dev;
105 config.dev->of_node = pdev->dev.parent->of_node;
106 config.regmap = regmap;
108 rdev = devm_regulator_register(&pdev->dev, &desc, &config);
110 dev_err(pdev->dev.parent, "Failed to register %s regulator\n",
112 return PTR_ERR(rdev);
118 static const struct platform_device_id sy7636a_regulator_id_table[] = {
119 { "sy7636a-regulator", },
122 MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
124 static struct platform_driver sy7636a_regulator_driver = {
126 .name = "sy7636a-regulator",
128 .probe = sy7636a_regulator_probe,
129 .id_table = sy7636a_regulator_id_table,
131 module_platform_driver(sy7636a_regulator_driver);
133 MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
134 MODULE_DESCRIPTION("SY7636A voltage regulator driver");
135 MODULE_LICENSE("GPL v2");