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22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/i2c.h>
25#include <linux/err.h>
26#include <linux/platform_device.h>
27#include <linux/regulator/driver.h>
28#include <linux/regulator/max8952.h>
29#include <linux/gpio.h>
30#include <linux/io.h>
31#include <linux/of.h>
32#include <linux/of_gpio.h>
33#include <linux/regulator/of_regulator.h>
34#include <linux/slab.h>
35
36
37enum {
38 MAX8952_REG_MODE0,
39 MAX8952_REG_MODE1,
40 MAX8952_REG_MODE2,
41 MAX8952_REG_MODE3,
42 MAX8952_REG_CONTROL,
43 MAX8952_REG_SYNC,
44 MAX8952_REG_RAMP,
45 MAX8952_REG_CHIP_ID1,
46 MAX8952_REG_CHIP_ID2,
47};
48
49struct max8952_data {
50 struct i2c_client *client;
51 struct max8952_platform_data *pdata;
52
53 bool vid0;
54 bool vid1;
55};
56
57static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
58{
59 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
60
61 if (ret > 0)
62 ret &= 0xff;
63
64 return ret;
65}
66
67static int max8952_write_reg(struct max8952_data *max8952,
68 u8 reg, u8 value)
69{
70 return i2c_smbus_write_byte_data(max8952->client, reg, value);
71}
72
73static int max8952_list_voltage(struct regulator_dev *rdev,
74 unsigned int selector)
75{
76 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
77
78 if (rdev_get_id(rdev) != 0)
79 return -EINVAL;
80
81 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
82}
83
84static int max8952_get_voltage_sel(struct regulator_dev *rdev)
85{
86 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
87 u8 vid = 0;
88
89 if (max8952->vid0)
90 vid += 1;
91 if (max8952->vid1)
92 vid += 2;
93
94 return vid;
95}
96
97static int max8952_set_voltage_sel(struct regulator_dev *rdev,
98 unsigned selector)
99{
100 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
101
102 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
103 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
104
105 return -EPERM;
106 }
107
108 max8952->vid0 = selector & 0x1;
109 max8952->vid1 = (selector >> 1) & 0x1;
110 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
111 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
112
113 return 0;
114}
115
116static struct regulator_ops max8952_ops = {
117 .list_voltage = max8952_list_voltage,
118 .get_voltage_sel = max8952_get_voltage_sel,
119 .set_voltage_sel = max8952_set_voltage_sel,
120};
121
122static const struct regulator_desc regulator = {
123 .name = "MAX8952_VOUT",
124 .id = 0,
125 .n_voltages = MAX8952_NUM_DVS_MODE,
126 .ops = &max8952_ops,
127 .type = REGULATOR_VOLTAGE,
128 .owner = THIS_MODULE,
129};
130
131#ifdef CONFIG_OF
132static const struct of_device_id max8952_dt_match[] = {
133 { .compatible = "maxim,max8952" },
134 {},
135};
136MODULE_DEVICE_TABLE(of, max8952_dt_match);
137
138static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
139{
140 struct max8952_platform_data *pd;
141 struct device_node *np = dev->of_node;
142 int ret;
143 int i;
144
145 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
146 if (!pd)
147 return NULL;
148
149 pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
150 pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
151 pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
152
153 if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
154 dev_warn(dev, "Default mode not specified, assuming 0\n");
155
156 ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
157 pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
158 if (ret) {
159 dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
160 return NULL;
161 }
162
163 for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
164 if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
165 dev_err(dev, "DVS voltage %d out of range\n", i);
166 return NULL;
167 }
168 pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
169 }
170
171 if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
172 dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
173
174 if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
175 dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
176
177 pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator);
178 if (!pd->reg_data) {
179 dev_err(dev, "Failed to parse regulator init data\n");
180 return NULL;
181 }
182
183 return pd;
184}
185#else
186static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
187{
188 return NULL;
189}
190#endif
191
192static int max8952_pmic_probe(struct i2c_client *client,
193 const struct i2c_device_id *i2c_id)
194{
195 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
196 struct max8952_platform_data *pdata = dev_get_platdata(&client->dev);
197 struct regulator_config config = { };
198 struct max8952_data *max8952;
199 struct regulator_dev *rdev;
200
201 int ret = 0, err = 0;
202
203 if (client->dev.of_node)
204 pdata = max8952_parse_dt(&client->dev);
205
206 if (!pdata) {
207 dev_err(&client->dev, "Require the platform data\n");
208 return -EINVAL;
209 }
210
211 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
212 return -EIO;
213
214 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
215 GFP_KERNEL);
216 if (!max8952)
217 return -ENOMEM;
218
219 max8952->client = client;
220 max8952->pdata = pdata;
221
222 config.dev = &client->dev;
223 config.init_data = pdata->reg_data;
224 config.driver_data = max8952;
225 config.of_node = client->dev.of_node;
226
227 config.ena_gpio = pdata->gpio_en;
228 if (client->dev.of_node)
229 config.ena_gpio_initialized = true;
230 if (pdata->reg_data->constraints.boot_on)
231 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
232
233 rdev = devm_regulator_register(&client->dev, ®ulator, &config);
234 if (IS_ERR(rdev)) {
235 ret = PTR_ERR(rdev);
236 dev_err(&client->dev, "regulator init failed (%d)\n", ret);
237 return ret;
238 }
239
240 max8952->vid0 = pdata->default_mode & 0x1;
241 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
242
243 if (gpio_is_valid(pdata->gpio_vid0) &&
244 gpio_is_valid(pdata->gpio_vid1)) {
245 unsigned long gpio_flags;
246
247 gpio_flags = max8952->vid0 ?
248 GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
249 if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0,
250 gpio_flags, "MAX8952 VID0"))
251 err = 1;
252
253 gpio_flags = max8952->vid1 ?
254 GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
255 if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1,
256 gpio_flags, "MAX8952 VID1"))
257 err = 2;
258 } else
259 err = 3;
260
261 if (err) {
262 dev_warn(&client->dev, "VID0/1 gpio invalid: "
263 "DVS not available.\n");
264 max8952->vid0 = 0;
265 max8952->vid1 = 0;
266
267 pdata->gpio_vid0 = -1;
268 pdata->gpio_vid1 = -1;
269
270
271 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
272
273 dev_err(&client->dev, "DVS modes disabled because VID0 and VID1"
274 " do not have proper controls.\n");
275 } else {
276
277
278
279
280
281
282
283
284 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
285 }
286
287 max8952_write_reg(max8952, MAX8952_REG_MODE0,
288 (max8952_read_reg(max8952,
289 MAX8952_REG_MODE0) & 0xC0) |
290 (pdata->dvs_mode[0] & 0x3F));
291 max8952_write_reg(max8952, MAX8952_REG_MODE1,
292 (max8952_read_reg(max8952,
293 MAX8952_REG_MODE1) & 0xC0) |
294 (pdata->dvs_mode[1] & 0x3F));
295 max8952_write_reg(max8952, MAX8952_REG_MODE2,
296 (max8952_read_reg(max8952,
297 MAX8952_REG_MODE2) & 0xC0) |
298 (pdata->dvs_mode[2] & 0x3F));
299 max8952_write_reg(max8952, MAX8952_REG_MODE3,
300 (max8952_read_reg(max8952,
301 MAX8952_REG_MODE3) & 0xC0) |
302 (pdata->dvs_mode[3] & 0x3F));
303
304 max8952_write_reg(max8952, MAX8952_REG_SYNC,
305 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
306 ((pdata->sync_freq & 0x3) << 6));
307 max8952_write_reg(max8952, MAX8952_REG_RAMP,
308 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
309 ((pdata->ramp_speed & 0x7) << 5));
310
311 i2c_set_clientdata(client, max8952);
312
313 return 0;
314}
315
316static const struct i2c_device_id max8952_ids[] = {
317 { "max8952", 0 },
318 { },
319};
320MODULE_DEVICE_TABLE(i2c, max8952_ids);
321
322static struct i2c_driver max8952_pmic_driver = {
323 .probe = max8952_pmic_probe,
324 .driver = {
325 .name = "max8952",
326 .of_match_table = of_match_ptr(max8952_dt_match),
327 },
328 .id_table = max8952_ids,
329};
330
331static int __init max8952_pmic_init(void)
332{
333 return i2c_add_driver(&max8952_pmic_driver);
334}
335subsys_initcall(max8952_pmic_init);
336
337static void __exit max8952_pmic_exit(void)
338{
339 i2c_del_driver(&max8952_pmic_driver);
340}
341module_exit(max8952_pmic_exit);
342
343MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
344MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
345MODULE_LICENSE("GPL");
346
