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>
16 #define SY7636A_POLL_ENABLED_TIME 500
18 static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
21 unsigned int val, val_h;
23 ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val);
27 ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h);
31 val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
33 return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
36 static int sy7636a_get_status(struct regulator_dev *rdev)
38 struct sy7636a *sy7636a = rdev_get_drvdata(rdev);
41 ret = gpiod_get_value_cansleep(sy7636a->pgood_gpio);
43 dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", ret);
48 static const struct regulator_ops sy7636a_vcom_volt_ops = {
49 .get_voltage = sy7636a_get_vcom_voltage_op,
50 .enable = regulator_enable_regmap,
51 .disable = regulator_disable_regmap,
52 .is_enabled = regulator_is_enabled_regmap,
53 .get_status = sy7636a_get_status,
56 static const struct regulator_desc desc = {
59 .ops = &sy7636a_vcom_volt_ops,
60 .type = REGULATOR_VOLTAGE,
62 .enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
63 .enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
64 .poll_enabled_time = SY7636A_POLL_ENABLED_TIME,
65 .regulators_node = of_match_ptr("regulators"),
66 .of_match = of_match_ptr("vcom"),
69 static int sy7636a_regulator_probe(struct platform_device *pdev)
71 struct sy7636a *sy7636a = dev_get_drvdata(pdev->dev.parent);
72 struct regulator_config config = { };
73 struct regulator_dev *rdev;
74 struct gpio_desc *gdp;
80 platform_set_drvdata(pdev, sy7636a);
82 gdp = devm_gpiod_get(sy7636a->dev, "epd-pwr-good", GPIOD_IN);
84 dev_err(sy7636a->dev, "Power good GPIO fault %ld\n", PTR_ERR(gdp));
88 sy7636a->pgood_gpio = gdp;
90 ret = regmap_write(sy7636a->regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
92 dev_err(sy7636a->dev, "Failed to initialize regulator: %d\n", ret);
96 config.dev = &pdev->dev;
97 config.dev->of_node = sy7636a->dev->of_node;
98 config.driver_data = sy7636a;
99 config.regmap = sy7636a->regmap;
101 rdev = devm_regulator_register(&pdev->dev, &desc, &config);
103 dev_err(sy7636a->dev, "Failed to register %s regulator\n",
105 return PTR_ERR(rdev);
111 static const struct platform_device_id sy7636a_regulator_id_table[] = {
112 { "sy7636a-regulator", },
115 MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
117 static struct platform_driver sy7636a_regulator_driver = {
119 .name = "sy7636a-regulator",
121 .probe = sy7636a_regulator_probe,
122 .id_table = sy7636a_regulator_id_table,
124 module_platform_driver(sy7636a_regulator_driver);
126 MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
127 MODULE_DESCRIPTION("SY7636A voltage regulator driver");
128 MODULE_LICENSE("GPL v2");