drivers/regulator/cros-ec-regulator.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 //
0003 // Copyright 2020 Google LLC.
0004
0005 #include <linux/module.h>
0006 #include <linux/of.h>
0007 #include <linux/platform_data/cros_ec_proto.h>
0008 #include <linux/platform_device.h>
0009 #include <linux/regulator/driver.h>
0010 #include <linux/regulator/machine.h>
0011 #include <linux/regulator/of_regulator.h>
0012 #include <linux/slab.h>
0013
0014 struct cros_ec_regulator_data {
0015     struct regulator_desc desc;
0016     struct regulator_dev *dev;
0017     struct cros_ec_device *ec_dev;
0018
0019     u32 index;
0020
0021     u16 *voltages_mV;
0022     u16 num_voltages;
0023 };
0024
0025 static int cros_ec_regulator_enable(struct regulator_dev *dev)
0026 {
0027     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0028     struct ec_params_regulator_enable cmd = {
0029         .index = data->index,
0030         .enable = 1,
0031     };
0032
0033     return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
0034                sizeof(cmd), NULL, 0);
0035 }
0036
0037 static int cros_ec_regulator_disable(struct regulator_dev *dev)
0038 {
0039     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0040     struct ec_params_regulator_enable cmd = {
0041         .index = data->index,
0042         .enable = 0,
0043     };
0044
0045     return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
0046                sizeof(cmd), NULL, 0);
0047 }
0048
0049 static int cros_ec_regulator_is_enabled(struct regulator_dev *dev)
0050 {
0051     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0052     struct ec_params_regulator_is_enabled cmd = {
0053         .index = data->index,
0054     };
0055     struct ec_response_regulator_is_enabled resp;
0056     int ret;
0057
0058     ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd,
0059               sizeof(cmd), &resp, sizeof(resp));
0060     if (ret < 0)
0061         return ret;
0062     return resp.enabled;
0063 }
0064
0065 static int cros_ec_regulator_list_voltage(struct regulator_dev *dev,
0066                       unsigned int selector)
0067 {
0068     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0069
0070     if (selector >= data->num_voltages)
0071         return -EINVAL;
0072
0073     return data->voltages_mV[selector] * 1000;
0074 }
0075
0076 static int cros_ec_regulator_get_voltage(struct regulator_dev *dev)
0077 {
0078     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0079     struct ec_params_regulator_get_voltage cmd = {
0080         .index = data->index,
0081     };
0082     struct ec_response_regulator_get_voltage resp;
0083     int ret;
0084
0085     ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd,
0086               sizeof(cmd), &resp, sizeof(resp));
0087     if (ret < 0)
0088         return ret;
0089     return resp.voltage_mv * 1000;
0090 }
0091
0092 static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
0093                      int max_uV, unsigned int *selector)
0094 {
0095     struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
0096     int min_mV = DIV_ROUND_UP(min_uV, 1000);
0097     int max_mV = max_uV / 1000;
0098     struct ec_params_regulator_set_voltage cmd = {
0099         .index = data->index,
0100         .min_mv = min_mV,
0101         .max_mv = max_mV,
0102     };
0103
0104     /*
0105      * This can happen when the given range [min_uV, max_uV] doesn't
0106      * contain any voltage that can be represented exactly in mV.
0107      */
0108     if (min_mV > max_mV)
0109         return -EINVAL;
0110
0111     return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd,
0112                sizeof(cmd), NULL, 0);
0113 }
0114
0115 static const struct regulator_ops cros_ec_regulator_voltage_ops = {
0116     .enable = cros_ec_regulator_enable,
0117     .disable = cros_ec_regulator_disable,
0118     .is_enabled = cros_ec_regulator_is_enabled,
0119     .list_voltage = cros_ec_regulator_list_voltage,
0120     .get_voltage = cros_ec_regulator_get_voltage,
0121     .set_voltage = cros_ec_regulator_set_voltage,
0122 };
0123
0124 static int cros_ec_regulator_init_info(struct device *dev,
0125                        struct cros_ec_regulator_data *data)
0126 {
0127     struct ec_params_regulator_get_info cmd = {
0128         .index = data->index,
0129     };
0130     struct ec_response_regulator_get_info resp;
0131     int ret;
0132
0133     ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd,
0134               sizeof(cmd), &resp, sizeof(resp));
0135     if (ret < 0)
0136         return ret;
0137
0138     data->num_voltages =
0139         min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages);
0140     data->voltages_mV =
0141         devm_kmemdup(dev, resp.voltages_mv,
0142                  sizeof(u16) * data->num_voltages, GFP_KERNEL);
0143     if (!data->voltages_mV)
0144         return -ENOMEM;
0145
0146     data->desc.n_voltages = data->num_voltages;
0147
0148     /* Make sure the returned name is always a valid string */
0149     resp.name[ARRAY_SIZE(resp.name) - 1] = '\0';
0150     data->desc.name = devm_kstrdup(dev, resp.name, GFP_KERNEL);
0151     if (!data->desc.name)
0152         return -ENOMEM;
0153
0154     return 0;
0155 }
0156
0157 static int cros_ec_regulator_probe(struct platform_device *pdev)
0158 {
0159     struct device *dev = &pdev->dev;
0160     struct device_node *np = dev->of_node;
0161     struct cros_ec_regulator_data *drvdata;
0162     struct regulator_init_data *init_data;
0163     struct regulator_config cfg = {};
0164     struct regulator_desc *desc;
0165     int ret;
0166
0167     drvdata = devm_kzalloc(
0168         &pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL);
0169     if (!drvdata)
0170         return -ENOMEM;
0171
0172     drvdata->ec_dev = dev_get_drvdata(dev->parent);
0173     desc = &drvdata->desc;
0174
0175     init_data = of_get_regulator_init_data(dev, np, desc);
0176     if (!init_data)
0177         return -EINVAL;
0178
0179     ret = of_property_read_u32(np, "reg", &drvdata->index);
0180     if (ret < 0)
0181         return ret;
0182
0183     desc->owner = THIS_MODULE;
0184     desc->type = REGULATOR_VOLTAGE;
0185     desc->ops = &cros_ec_regulator_voltage_ops;
0186
0187     ret = cros_ec_regulator_init_info(dev, drvdata);
0188     if (ret < 0)
0189         return ret;
0190
0191     cfg.dev = &pdev->dev;
0192     cfg.init_data = init_data;
0193     cfg.driver_data = drvdata;
0194     cfg.of_node = np;
0195
0196     drvdata->dev = devm_regulator_register(dev, &drvdata->desc, &cfg);
0197     if (IS_ERR(drvdata->dev)) {
0198         ret = PTR_ERR(drvdata->dev);
0199         dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
0200         return ret;
0201     }
0202
0203     platform_set_drvdata(pdev, drvdata);
0204
0205     return 0;
0206 }
0207
0208 static const struct of_device_id regulator_cros_ec_of_match[] = {
0209     { .compatible = "google,cros-ec-regulator", },
0210     {}
0211 };
0212 MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
0213
0214 static struct platform_driver cros_ec_regulator_driver = {
0215     .probe      = cros_ec_regulator_probe,
0216     .driver     = {
0217         .name       = "cros-ec-regulator",
0218         .of_match_table = regulator_cros_ec_of_match,
0219     },
0220 };
0221
0222 module_platform_driver(cros_ec_regulator_driver);
0223
0224 MODULE_LICENSE("GPL v2");
0225 MODULE_DESCRIPTION("ChromeOS EC controlled regulator");
0226 MODULE_AUTHOR("Pi-Hsun Shih <pihsun@chromium.org>");