diff options
Diffstat (limited to 'drivers/regulator/sy7636a-regulator.c')
| -rw-r--r-- | drivers/regulator/sy7636a-regulator.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/regulator/sy7636a-regulator.c b/drivers/regulator/sy7636a-regulator.c new file mode 100644 index 000000000000..551647bc1052 --- /dev/null +++ b/drivers/regulator/sy7636a-regulator.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Functions to access SY3686A power management chip voltages +// +// Copyright (C) 2019 reMarkable AS - http://www.remarkable.com/ +// +// Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com> +// Alistair Francis <alistair@alistair23.me> + +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/mfd/sy7636a.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regulator/consumer.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/machine.h> +#include <linux/regmap.h> + +struct sy7636a_data { + struct regmap *regmap; + struct gpio_desc *pgood_gpio; + struct gpio_desc *en_gpio; + struct gpio_desc *vcom_en_gpio; +}; + +static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev) +{ + int ret; + unsigned int val, val_h; + + ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val); + if (ret) + return ret; + + ret = regmap_read(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, &val_h); + if (ret) + return ret; + + val |= (val_h << VCOM_ADJUST_CTRL_SHIFT); + + return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL; +} + +static int sy7636a_get_status(struct regulator_dev *rdev) +{ + struct sy7636a_data *data = dev_get_drvdata(rdev->dev.parent); + int ret = 0; + + ret = gpiod_get_value_cansleep(data->pgood_gpio); + if (ret < 0) + dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", ret); + + return ret; +} + +static const struct regulator_ops sy7636a_vcom_volt_ops = { + .get_voltage = sy7636a_get_vcom_voltage_op, + .enable = regulator_enable_regmap, + .disable = regulator_disable_regmap, + .is_enabled = regulator_is_enabled_regmap, + .get_status = sy7636a_get_status, +}; + +static const struct regulator_desc desc = { + .name = "vcom", + .id = 0, + .ops = &sy7636a_vcom_volt_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .enable_reg = SY7636A_REG_OPERATION_MODE_CRL, + .enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF, + .regulators_node = of_match_ptr("regulators"), + .of_match = of_match_ptr("vcom"), +}; + +static int sy7636a_regulator_probe(struct platform_device *pdev) +{ + struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL); + struct regulator_config config = { }; + struct regulator_dev *rdev; + struct gpio_desc *gdp; + struct sy7636a_data *data; + int ret; + + if (!regmap) + return -EPROBE_DEFER; + + device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent); + + gdp = devm_gpiod_get(&pdev->dev, "epd-pwr-good", GPIOD_IN); + if (IS_ERR(gdp)) { + dev_err(&pdev->dev, "Power good GPIO fault %ld\n", PTR_ERR(gdp)); + return PTR_ERR(gdp); + } + + data = devm_kzalloc(&pdev->dev, sizeof(struct sy7636a_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->regmap = regmap; + data->pgood_gpio = gdp; + + ret = devm_regulator_get_enable_optional(&pdev->dev, "vin"); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "failed to get vin regulator\n"); + + data->en_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_HIGH); + if (IS_ERR(data->en_gpio)) + return dev_err_probe(&pdev->dev, + PTR_ERR(data->en_gpio), + "failed to get en gpio\n"); + + /* Let VCOM just follow the default power on sequence */ + data->vcom_en_gpio = devm_gpiod_get_optional(&pdev->dev, + "vcom-en", GPIOD_OUT_LOW); + if (IS_ERR(data->vcom_en_gpio)) + return dev_err_probe(&pdev->dev, + PTR_ERR(data->vcom_en_gpio), + "failed to get vcom-en gpio\n"); + + /* if chip was not enabled, give it time to wake up */ + if (data->en_gpio) + usleep_range(2500, 4000); + + platform_set_drvdata(pdev, data); + + ret = regmap_write(regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0); + if (ret) { + dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n", ret); + return ret; + } + + config.dev = &pdev->dev; + config.regmap = regmap; + + rdev = devm_regulator_register(&pdev->dev, &desc, &config); + if (IS_ERR(rdev)) { + dev_err(pdev->dev.parent, "Failed to register %s regulator\n", + pdev->name); + return PTR_ERR(rdev); + } + + return 0; +} + +static const struct platform_device_id sy7636a_regulator_id_table[] = { + { "sy7636a-regulator", }, + { } +}; +MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table); + +static struct platform_driver sy7636a_regulator_driver = { + .driver = { + .name = "sy7636a-regulator", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, + .probe = sy7636a_regulator_probe, + .id_table = sy7636a_regulator_id_table, +}; +module_platform_driver(sy7636a_regulator_driver); + +MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>"); +MODULE_DESCRIPTION("SY7636A voltage regulator driver"); +MODULE_LICENSE("GPL v2"); |