1 // SPDX-License-Identifier: GPL-2.0-only 2 // 3 // Copyright 2020 Google LLC. 4 5 #include <linux/module.h> 6 #include <linux/of.h> 7 #include <linux/platform_data/cros_ec_proto.h> 8 #include <linux/platform_device.h> 9 #include <linux/regulator/driver.h> 10 #include <linux/regulator/machine.h> 11 #include <linux/regulator/of_regulator.h> 12 #include <linux/slab.h> 13 14 struct cros_ec_regulator_data { 15 struct regulator_desc desc; 16 struct regulator_dev *dev; 17 struct cros_ec_device *ec_dev; 18 19 u32 index; 20 21 u16 *voltages_mV; 22 u16 num_voltages; 23 }; 24 25 static int cros_ec_regulator_enable(struct regulator_dev *dev) 26 { 27 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 28 struct ec_params_regulator_enable cmd = { 29 .index = data->index, 30 .enable = 1, 31 }; 32 33 return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd, 34 sizeof(cmd), NULL, 0); 35 } 36 37 static int cros_ec_regulator_disable(struct regulator_dev *dev) 38 { 39 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 40 struct ec_params_regulator_enable cmd = { 41 .index = data->index, 42 .enable = 0, 43 }; 44 45 return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd, 46 sizeof(cmd), NULL, 0); 47 } 48 49 static int cros_ec_regulator_is_enabled(struct regulator_dev *dev) 50 { 51 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 52 struct ec_params_regulator_is_enabled cmd = { 53 .index = data->index, 54 }; 55 struct ec_response_regulator_is_enabled resp; 56 int ret; 57 58 ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd, 59 sizeof(cmd), &resp, sizeof(resp)); 60 if (ret < 0) 61 return ret; 62 return resp.enabled; 63 } 64 65 static int cros_ec_regulator_list_voltage(struct regulator_dev *dev, 66 unsigned int selector) 67 { 68 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 69 70 if (selector >= data->num_voltages) 71 return -EINVAL; 72 73 return data->voltages_mV[selector] * 1000; 74 } 75 76 static int cros_ec_regulator_get_voltage(struct regulator_dev *dev) 77 { 78 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 79 struct ec_params_regulator_get_voltage cmd = { 80 .index = data->index, 81 }; 82 struct ec_response_regulator_get_voltage resp; 83 int ret; 84 85 ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd, 86 sizeof(cmd), &resp, sizeof(resp)); 87 if (ret < 0) 88 return ret; 89 return resp.voltage_mv * 1000; 90 } 91 92 static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV, 93 int max_uV, unsigned int *selector) 94 { 95 struct cros_ec_regulator_data *data = rdev_get_drvdata(dev); 96 int min_mV = DIV_ROUND_UP(min_uV, 1000); 97 int max_mV = max_uV / 1000; 98 struct ec_params_regulator_set_voltage cmd = { 99 .index = data->index, 100 .min_mv = min_mV, 101 .max_mv = max_mV, 102 }; 103 104 /* 105 * This can happen when the given range [min_uV, max_uV] doesn't 106 * contain any voltage that can be represented exactly in mV. 107 */ 108 if (min_mV > max_mV) 109 return -EINVAL; 110 111 return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd, 112 sizeof(cmd), NULL, 0); 113 } 114 115 static const struct regulator_ops cros_ec_regulator_voltage_ops = { 116 .enable = cros_ec_regulator_enable, 117 .disable = cros_ec_regulator_disable, 118 .is_enabled = cros_ec_regulator_is_enabled, 119 .list_voltage = cros_ec_regulator_list_voltage, 120 .get_voltage = cros_ec_regulator_get_voltage, 121 .set_voltage = cros_ec_regulator_set_voltage, 122 }; 123 124 static int cros_ec_regulator_init_info(struct device *dev, 125 struct cros_ec_regulator_data *data) 126 { 127 struct ec_params_regulator_get_info cmd = { 128 .index = data->index, 129 }; 130 struct ec_response_regulator_get_info resp; 131 int ret; 132 133 ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd, 134 sizeof(cmd), &resp, sizeof(resp)); 135 if (ret < 0) 136 return ret; 137 138 data->num_voltages = 139 min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages); 140 data->voltages_mV = 141 devm_kmemdup(dev, resp.voltages_mv, 142 sizeof(u16) * data->num_voltages, GFP_KERNEL); 143 if (!data->voltages_mV) 144 return -ENOMEM; 145 146 data->desc.n_voltages = data->num_voltages; 147 148 /* Make sure the returned name is always a valid string */ 149 resp.name[ARRAY_SIZE(resp.name) - 1] = '\0'; 150 data->desc.name = devm_kstrdup(dev, resp.name, GFP_KERNEL); 151 if (!data->desc.name) 152 return -ENOMEM; 153 154 return 0; 155 } 156 157 static int cros_ec_regulator_probe(struct platform_device *pdev) 158 { 159 struct device *dev = &pdev->dev; 160 struct device_node *np = dev->of_node; 161 struct cros_ec_regulator_data *drvdata; 162 struct regulator_init_data *init_data; 163 struct regulator_config cfg = {}; 164 struct regulator_desc *desc; 165 int ret; 166 167 drvdata = devm_kzalloc( 168 &pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL); 169 if (!drvdata) 170 return -ENOMEM; 171 172 drvdata->ec_dev = dev_get_drvdata(dev->parent); 173 desc = &drvdata->desc; 174 175 init_data = of_get_regulator_init_data(dev, np, desc); 176 if (!init_data) 177 return -EINVAL; 178 179 ret = of_property_read_u32(np, "reg", &drvdata->index); 180 if (ret < 0) 181 return ret; 182 183 desc->owner = THIS_MODULE; 184 desc->type = REGULATOR_VOLTAGE; 185 desc->ops = &cros_ec_regulator_voltage_ops; 186 187 ret = cros_ec_regulator_init_info(dev, drvdata); 188 if (ret < 0) 189 return ret; 190 191 cfg.dev = &pdev->dev; 192 cfg.init_data = init_data; 193 cfg.driver_data = drvdata; 194 cfg.of_node = np; 195 196 drvdata->dev = devm_regulator_register(dev, &drvdata->desc, &cfg); 197 if (IS_ERR(drvdata->dev)) { 198 ret = PTR_ERR(drvdata->dev); 199 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); 200 return ret; 201 } 202 203 platform_set_drvdata(pdev, drvdata); 204 205 return 0; 206 } 207 208 static const struct of_device_id regulator_cros_ec_of_match[] = { 209 { .compatible = "google,cros-ec-regulator", }, 210 {} 211 }; 212 MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match); 213 214 static struct platform_driver cros_ec_regulator_driver = { 215 .probe = cros_ec_regulator_probe, 216 .driver = { 217 .name = "cros-ec-regulator", 218 .of_match_table = regulator_cros_ec_of_match, 219 }, 220 }; 221 222 module_platform_driver(cros_ec_regulator_driver); 223 224 MODULE_LICENSE("GPL v2"); 225 MODULE_DESCRIPTION("ChromeOS EC controlled regulator"); 226 MODULE_AUTHOR("Pi-Hsun Shih <pihsun@chromium.org>"); 227