cros-ec-regulator.c 6.4 KB

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