Initial support for the Silergy SY7636A-regulator Power Management chip. Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx> --- v3: - Move sysfs power from mfd to regulaator - Add ABI documentation v2: - N/A .../testing/sysfs-driver-sy7636a-regulator | 21 ++ drivers/regulator/Kconfig | 6 + drivers/regulator/Makefile | 1 + drivers/regulator/sy7636a-regulator.c | 354 ++++++++++++++++++ include/linux/mfd/sy7636a.h | 1 + 5 files changed, 383 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-sy7636a-regulator create mode 100644 drivers/regulator/sy7636a-regulator.c diff --git a/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator b/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator new file mode 100644 index 000000000000..ab534a8ea21a --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-sy7636a-regulator @@ -0,0 +1,21 @@ +What: /sys/bus/regulator/drivers/sy7636a-regulator/state +Date: April 2021 +KernelVersion: 5.12 +Contact: alistair@xxxxxxxxxxxxx +Description: + This file allows you to see the current power rail state. + +What: /sys/bus/regulator/drivers/sy7636a-regulator/power_good +Date: April 2021 +KernelVersion: 5.12 +Contact: alistair@xxxxxxxxxxxxx +Description: + This file allows you to see the current state of the regulator + as either ON or OFF. + +What: /sys/bus/regulator/drivers/sy7636a-regulator/vcom +Date: April 2021 +KernelVersion: 5.12 +Contact: alistair@xxxxxxxxxxxxx +Description: + This file allows you to see and set the current voltage in mV. diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig index 77c43134bc9e..6d501ce921a8 100644 --- a/drivers/regulator/Kconfig +++ b/drivers/regulator/Kconfig @@ -1130,6 +1130,12 @@ config REGULATOR_STW481X_VMMC This driver supports the internal VMMC regulator in the STw481x PMIC chips. +config REGULATOR_SY7636A + tristate "Silergy SY7636A voltage regulator" + depends on MFD_SY7636A + help + This driver supports Silergy SY3686A voltage regulator. + config REGULATOR_SY8106A tristate "Silergy SY8106A regulator" depends on I2C && (OF || COMPILE_TEST) diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile index 44d2f8bf4b74..5a981036a9f0 100644 --- a/drivers/regulator/Makefile +++ b/drivers/regulator/Makefile @@ -134,6 +134,7 @@ obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o +obj-$(CONFIG_REGULATOR_SY7636A) += sy7636a-regulator.o obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o obj-$(CONFIG_REGULATOR_SY8824X) += sy8824x.o obj-$(CONFIG_REGULATOR_SY8827N) += sy8827n.o diff --git a/drivers/regulator/sy7636a-regulator.c b/drivers/regulator/sy7636a-regulator.c new file mode 100644 index 000000000000..0ec6f852cb3d --- /dev/null +++ b/drivers/regulator/sy7636a-regulator.c @@ -0,0 +1,354 @@ +// 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@xxxxxxxxxxxxxx> +// Alistair Francis <alistair@xxxxxxxxxxxxx> + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/sysfs.h> +#include <linux/gpio/consumer.h> +#include <linux/mfd/sy7636a.h> + +static const char * const states[] = { + "no fault event", + "UVP at VP rail", + "UVP at VN rail", + "UVP at VPOS rail", + "UVP at VNEG rail", + "UVP at VDDH rail", + "UVP at VEE rail", + "SCP at VP rail", + "SCP at VN rail", + "SCP at VPOS rail", + "SCP at VNEG rail", + "SCP at VDDH rail", + "SCP at VEE rail", + "SCP at V COM rail", + "UVLO", + "Thermal shutdown", +}; + +static int sy7636a_get_vcom_voltage_mv(struct regmap *regmap) +{ + int ret; + unsigned int val, val_h; + + ret = regmap_read(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, &val); + if (ret) + return ret; + + ret = regmap_read(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_set_vcom_voltage_mv(struct regmap *regmap, unsigned int vcom) +{ + int ret; + unsigned int val; + + if (vcom < VCOM_MIN || vcom > VCOM_MAX) + return -EINVAL; + + val = (unsigned int)(vcom / VCOM_ADJUST_CTRL_SCAL) & VCOM_ADJUST_CTRL_MASK; + + ret = regmap_write(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, val); + if (ret) + return ret; + + ret = regmap_write(regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, val >> VCOM_ADJUST_CTRL_SHIFT); + if (ret) + return ret; + + return 0; +} + +static ssize_t state_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int ret; + unsigned int val; + struct sy7636a *sy7636a = dev_get_drvdata(dev); + + ret = regmap_read(sy7636a->regmap, SY7636A_REG_FAULT_FLAG, &val); + if (ret) { + dev_err(sy7636a->dev, "Failed to read from device\n"); + return ret; + } + + val = val >> FAULT_FLAG_SHIFT; + + if (val >= ARRAY_SIZE(states)) { + dev_err(sy7636a->dev, "Unexpected value read from device: %u\n", val); + return -EINVAL; + } + + return snprintf(buf, PAGE_SIZE, "%s\n", states[val]); +} +static DEVICE_ATTR(state, 0444, state_show, NULL); + +static ssize_t power_good_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int ret; + unsigned int val; + struct sy7636a *sy7636a = dev_get_drvdata(dev); + + ret = regmap_read(sy7636a->regmap, SY7636A_REG_FAULT_FLAG, &val); + if (ret) { + dev_err(sy7636a->dev, "Failed to read from device\n"); + return ret; + } + + val &= (1 << FAULT_FLAG_SHIFT) - 1; + + return snprintf(buf, PAGE_SIZE, "%s\n", val ? "ON" : "OFF"); +} +static DEVICE_ATTR(power_good, 0444, power_good_show, NULL); + +static ssize_t vcom_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int ret; + struct sy7636a *sy7636a = dev_get_drvdata(dev); + + ret = sy7636a_get_vcom_voltage_mv(sy7636a->regmap); + if (ret < 0) + return ret; + + return snprintf(buf, PAGE_SIZE, "%d\n", -ret); +} +static ssize_t vcom_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + int vcom; + struct sy7636a *sy7636a = dev_get_drvdata(dev); + + ret = kstrtoint(buf, 0, &vcom); + if (ret) + return ret; + + if (vcom > 0 || vcom < -5000) + return -EINVAL; + + ret = sy7636a_set_vcom_voltage_mv(sy7636a->regmap, (unsigned int)(-vcom)); + if (ret) + return ret; + + return count; +} +static DEVICE_ATTR(vcom, 0644, vcom_show, vcom_store); + +static struct attribute *sy7636a_sysfs_attrs[] = { + &dev_attr_state.attr, + &dev_attr_power_good.attr, + &dev_attr_vcom.attr, + NULL, +}; + +static const struct attribute_group sy7636a_sysfs_attr_group = { + .attrs = sy7636a_sysfs_attrs, +}; + +static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev) +{ + return sy7636a_get_vcom_voltage_mv(rdev->regmap); +} + +static int sy7636a_disable_regulator(struct regulator_dev *rdev) +{ + int ret = 0; + + ret = regulator_disable_regmap(rdev); + // Delay for ~35ms after disabling the regulator, to allow power ramp + // down to go undisturbed + usleep_range(30000, 35000); + + return ret; +} + +static int sy7636a_regulator_is_enabled(struct regulator_dev *rdev) +{ + return regulator_is_enabled_regmap(rdev); +} + +static int sy7636a_get_status(struct regulator_dev *rdev) +{ + struct sy7636a *sy7636a = dev_get_drvdata(rdev->dev.parent); + int pwr_good = 0; + const unsigned int wait_time = 500; + unsigned int wait_cnt; + int ret = 0; + + for (wait_cnt = 0; wait_cnt < wait_time; wait_cnt++) { + pwr_good = gpiod_get_value_cansleep(sy7636a->pgood_gpio); + if (pwr_good < 0) { + dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", pwr_good); + ret = pwr_good; + return ret; + } else if (pwr_good) + break; + + usleep_range(1000, 1500); + } + + return ret; +} + +static int sy7636a_enable_regulator_pgood(struct regulator_dev *rdev) +{ + struct sy7636a *sy7636a = dev_get_drvdata(rdev->dev.parent); + int pwr_good = 0; + int ret = 0; + unsigned long t0, t1; + const unsigned int wait_time = 500; + unsigned int wait_cnt; + + t0 = jiffies; + + ret = regulator_enable_regmap(rdev); + if (ret) + goto finish; + + for (wait_cnt = 0; wait_cnt < wait_time; wait_cnt++) { + pwr_good = gpiod_get_value_cansleep(sy7636a->pgood_gpio); + if (pwr_good < 0) { + dev_err(&rdev->dev, "Failed to read pgood gpio: %d\n", pwr_good); + ret = pwr_good; + goto finish; + } else if (pwr_good) + break; + + usleep_range(1000, 1500); + } + + t1 = jiffies; + + if (!pwr_good) { + dev_err(&rdev->dev, "Power good signal timeout after %u ms\n", + jiffies_to_msecs(t1 - t0)); + ret = -ETIME; + sy7636a_disable_regulator(rdev); + goto finish; + } + + ret = sysfs_create_group(&rdev->dev.kobj, &sy7636a_sysfs_attr_group); + if (ret) { + dev_err(sy7636a->dev, "Failed to create sysfs attributes\n"); + return ret; + } + + if (ret) { + dev_err(sy7636a->dev, "Failed to add child devices\n"); + sysfs_remove_group(&rdev->dev.kobj, &sy7636a_sysfs_attr_group); + return ret; + } + + dev_dbg(&rdev->dev, "Power good OK (took %u ms, %u waits)\n", + jiffies_to_msecs(t1 - t0), + wait_cnt); + +finish: + return ret; +} + +static const struct regulator_ops sy7636a_vcom_volt_ops = { + .get_voltage = sy7636a_get_vcom_voltage_op, + .enable = sy7636a_enable_regulator_pgood, + .disable = sy7636a_disable_regulator, + .is_enabled = sy7636a_regulator_is_enabled, + .get_status = sy7636a_get_status, +}; + +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_init(struct sy7636a *sy7636a) +{ + return regmap_write(sy7636a->regmap, + SY7636A_REG_POWER_ON_DELAY_TIME, + 0x0); +} + +static int sy7636a_regulator_probe(struct platform_device *pdev) +{ + struct sy7636a *sy7636a = dev_get_drvdata(pdev->dev.parent); + struct regulator_config config = { }; + struct regulator_dev *rdev; + struct gpio_desc *gdp; + int ret; + + if (!sy7636a) + return -EPROBE_DEFER; + + platform_set_drvdata(pdev, sy7636a); + + gdp = devm_gpiod_get(sy7636a->dev, "epd-pwr-good", GPIOD_IN); + if (IS_ERR(gdp)) { + dev_err(sy7636a->dev, "Power good GPIO fault %ld\n", PTR_ERR(gdp)); + return PTR_ERR(gdp); + } + + sy7636a->pgood_gpio = gdp; + + ret = sy7636a_regulator_init(sy7636a); + if (ret) { + dev_err(sy7636a->dev, "Failed to initialize regulator: %d\n", ret); + return ret; + } + + config.dev = &pdev->dev; + config.dev->of_node = sy7636a->dev->of_node; + config.driver_data = sy7636a; + config.regmap = sy7636a->regmap; + + rdev = devm_regulator_register(&pdev->dev, &desc, &config); + if (IS_ERR(rdev)) { + dev_err(sy7636a->dev, "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 = sy7636a_regulator_probe, + .id_table = sy7636a_regulator_id_table, +}; +module_platform_driver(sy7636a_regulator_driver); + +MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@xxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("SY7636A voltage regulator driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/mfd/sy7636a.h b/include/linux/mfd/sy7636a.h index a5ec5d911b3a..1f8d7507a700 100644 --- a/include/linux/mfd/sy7636a.h +++ b/include/linux/mfd/sy7636a.h @@ -41,6 +41,7 @@ struct sy7636a { struct device *dev; struct regmap *regmap; + struct gpio_desc *pgood_gpio; }; #endif /* __LINUX_MFD_SY7636A_H */ -- 2.31.0
