diff options
Diffstat (limited to 'drivers/regulator/cros-ec-regulator.c')
| -rw-r--r-- | drivers/regulator/cros-ec-regulator.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/regulator/cros-ec-regulator.c b/drivers/regulator/cros-ec-regulator.c new file mode 100644 index 0000000000..fb9643ed7a --- /dev/null +++ b/drivers/regulator/cros-ec-regulator.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Copyright 2020 Google LLC. + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/machine.h> +#include <linux/regulator/of_regulator.h> +#include <linux/slab.h> + +struct cros_ec_regulator_data { + struct regulator_desc desc; + struct regulator_dev *dev; + struct cros_ec_device *ec_dev; + + u32 index; + + u16 *voltages_mV; + u16 num_voltages; +}; + +static int cros_ec_regulator_enable(struct regulator_dev *dev) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + struct ec_params_regulator_enable cmd = { + .index = data->index, + .enable = 1, + }; + + return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd, + sizeof(cmd), NULL, 0); +} + +static int cros_ec_regulator_disable(struct regulator_dev *dev) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + struct ec_params_regulator_enable cmd = { + .index = data->index, + .enable = 0, + }; + + return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd, + sizeof(cmd), NULL, 0); +} + +static int cros_ec_regulator_is_enabled(struct regulator_dev *dev) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + struct ec_params_regulator_is_enabled cmd = { + .index = data->index, + }; + struct ec_response_regulator_is_enabled resp; + int ret; + + ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd, + sizeof(cmd), &resp, sizeof(resp)); + if (ret < 0) + return ret; + return resp.enabled; +} + +static int cros_ec_regulator_list_voltage(struct regulator_dev *dev, + unsigned int selector) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + + if (selector >= data->num_voltages) + return -EINVAL; + + return data->voltages_mV[selector] * 1000; +} + +static int cros_ec_regulator_get_voltage(struct regulator_dev *dev) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + struct ec_params_regulator_get_voltage cmd = { + .index = data->index, + }; + struct ec_response_regulator_get_voltage resp; + int ret; + + ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd, + sizeof(cmd), &resp, sizeof(resp)); + if (ret < 0) + return ret; + return resp.voltage_mv * 1000; +} + +static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV, + int max_uV, unsigned int *selector) +{ + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); + int min_mV = DIV_ROUND_UP(min_uV, 1000); + int max_mV = max_uV / 1000; + struct ec_params_regulator_set_voltage cmd = { + .index = data->index, + .min_mv = min_mV, + .max_mv = max_mV, + }; + + /* + * This can happen when the given range [min_uV, max_uV] doesn't + * contain any voltage that can be represented exactly in mV. + */ + if (min_mV > max_mV) + return -EINVAL; + + return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd, + sizeof(cmd), NULL, 0); +} + +static const struct regulator_ops cros_ec_regulator_voltage_ops = { + .enable = cros_ec_regulator_enable, + .disable = cros_ec_regulator_disable, + .is_enabled = cros_ec_regulator_is_enabled, + .list_voltage = cros_ec_regulator_list_voltage, + .get_voltage = cros_ec_regulator_get_voltage, + .set_voltage = cros_ec_regulator_set_voltage, +}; + +static int cros_ec_regulator_init_info(struct device *dev, + struct cros_ec_regulator_data *data) +{ + struct ec_params_regulator_get_info cmd = { + .index = data->index, + }; + struct ec_response_regulator_get_info resp; + int ret; + + ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd, + sizeof(cmd), &resp, sizeof(resp)); + if (ret < 0) + return ret; + + data->num_voltages = + min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages); + data->voltages_mV = + devm_kmemdup(dev, resp.voltages_mv, + sizeof(u16) * data->num_voltages, GFP_KERNEL); + if (!data->voltages_mV) + return -ENOMEM; + + data->desc.n_voltages = data->num_voltages; + + /* Make sure the returned name is always a valid string */ + resp.name[ARRAY_SIZE(resp.name) - 1] = '\0'; + data->desc.name = devm_kstrdup(dev, resp.name, GFP_KERNEL); + if (!data->desc.name) + return -ENOMEM; + + return 0; +} + +static int cros_ec_regulator_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct cros_ec_regulator_data *drvdata; + struct regulator_init_data *init_data; + struct regulator_config cfg = {}; + struct regulator_desc *desc; + int ret; + + drvdata = devm_kzalloc( + &pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + drvdata->ec_dev = dev_get_drvdata(dev->parent); + desc = &drvdata->desc; + + init_data = of_get_regulator_init_data(dev, np, desc); + if (!init_data) + return -EINVAL; + + ret = of_property_read_u32(np, "reg", &drvdata->index); + if (ret < 0) + return ret; + + desc->owner = THIS_MODULE; + desc->type = REGULATOR_VOLTAGE; + desc->ops = &cros_ec_regulator_voltage_ops; + + ret = cros_ec_regulator_init_info(dev, drvdata); + if (ret < 0) + return ret; + + cfg.dev = &pdev->dev; + cfg.init_data = init_data; + cfg.driver_data = drvdata; + cfg.of_node = np; + + drvdata->dev = devm_regulator_register(dev, &drvdata->desc, &cfg); + if (IS_ERR(drvdata->dev)) { + ret = PTR_ERR(drvdata->dev); + dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, drvdata); + + return 0; +} + +static const struct of_device_id regulator_cros_ec_of_match[] = { + { .compatible = "google,cros-ec-regulator", }, + {} +}; +MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match); + +static struct platform_driver cros_ec_regulator_driver = { + .probe = cros_ec_regulator_probe, + .driver = { + .name = "cros-ec-regulator", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = regulator_cros_ec_of_match, + }, +}; + +module_platform_driver(cros_ec_regulator_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("ChromeOS EC controlled regulator"); +MODULE_AUTHOR("Pi-Hsun Shih <pihsun@chromium.org>"); |