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
cros_ec_regulator_enable(struct regulator_dev * dev)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
cros_ec_regulator_disable(struct regulator_dev * dev)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
cros_ec_regulator_is_enabled(struct regulator_dev * dev)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
cros_ec_regulator_list_voltage(struct regulator_dev * dev,unsigned int selector)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
cros_ec_regulator_get_voltage(struct regulator_dev * dev)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
cros_ec_regulator_set_voltage(struct regulator_dev * dev,int min_uV,int max_uV,unsigned int * selector)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
cros_ec_regulator_init_info(struct device * dev,struct cros_ec_regulator_data * data)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
cros_ec_regulator_probe(struct platform_device * pdev)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 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
219 .of_match_table = regulator_cros_ec_of_match,
220 },
221 };
222
223 module_platform_driver(cros_ec_regulator_driver);
224
225 MODULE_LICENSE("GPL v2");
226 MODULE_DESCRIPTION("ChromeOS EC controlled regulator");
227 MODULE_AUTHOR("Pi-Hsun Shih <pihsun@chromium.org>");
228