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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 device *dev;
52 struct max8952_platform_data *pdata;
53 struct regulator_dev *rdev;
54
55 bool vid0;
56 bool vid1;
57};
58
59static int max8952_read_reg(struct max8952_data *max8952, u8 reg)
60{
61 int ret = i2c_smbus_read_byte_data(max8952->client, reg);
62 if (ret > 0)
63 ret &= 0xff;
64
65 return ret;
66}
67
68static int max8952_write_reg(struct max8952_data *max8952,
69 u8 reg, u8 value)
70{
71 return i2c_smbus_write_byte_data(max8952->client, reg, value);
72}
73
74static int max8952_list_voltage(struct regulator_dev *rdev,
75 unsigned int selector)
76{
77 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
78
79 if (rdev_get_id(rdev) != 0)
80 return -EINVAL;
81
82 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000;
83}
84
85static int max8952_get_voltage_sel(struct regulator_dev *rdev)
86{
87 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
88 u8 vid = 0;
89
90 if (max8952->vid0)
91 vid += 1;
92 if (max8952->vid1)
93 vid += 2;
94
95 return vid;
96}
97
98static int max8952_set_voltage_sel(struct regulator_dev *rdev,
99 unsigned selector)
100{
101 struct max8952_data *max8952 = rdev_get_drvdata(rdev);
102
103 if (!gpio_is_valid(max8952->pdata->gpio_vid0) ||
104 !gpio_is_valid(max8952->pdata->gpio_vid1)) {
105
106 return -EPERM;
107 }
108
109 max8952->vid0 = selector & 0x1;
110 max8952->vid1 = (selector >> 1) & 0x1;
111 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0);
112 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1);
113
114 return 0;
115}
116
117static struct regulator_ops max8952_ops = {
118 .list_voltage = max8952_list_voltage,
119 .get_voltage_sel = max8952_get_voltage_sel,
120 .set_voltage_sel = max8952_set_voltage_sel,
121};
122
123static const struct regulator_desc regulator = {
124 .name = "MAX8952_VOUT",
125 .id = 0,
126 .n_voltages = MAX8952_NUM_DVS_MODE,
127 .ops = &max8952_ops,
128 .type = REGULATOR_VOLTAGE,
129 .owner = THIS_MODULE,
130};
131
132#ifdef CONFIG_OF
133static struct of_device_id max8952_dt_match[] = {
134 { .compatible = "maxim,max8952" },
135 {},
136};
137MODULE_DEVICE_TABLE(of, max8952_dt_match);
138
139static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
140{
141 struct max8952_platform_data *pd;
142 struct device_node *np = dev->of_node;
143 int ret;
144 int i;
145
146 pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
147 if (!pd) {
148 dev_err(dev, "Failed to allocate platform data\n");
149 return NULL;
150 }
151
152 pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0);
153 pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1);
154 pd->gpio_en = of_get_named_gpio(np, "max8952,en-gpio", 0);
155
156 if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode))
157 dev_warn(dev, "Default mode not specified, assuming 0\n");
158
159 ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt",
160 pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode));
161 if (ret) {
162 dev_err(dev, "max8952,dvs-mode-microvolt property not specified");
163 return NULL;
164 }
165
166 for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) {
167 if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) {
168 dev_err(dev, "DVS voltage %d out of range\n", i);
169 return NULL;
170 }
171 pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000;
172 }
173
174 if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq))
175 dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n");
176
177 if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed))
178 dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n");
179
180 pd->reg_data = of_get_regulator_init_data(dev, np);
181 if (!pd->reg_data) {
182 dev_err(dev, "Failed to parse regulator init data\n");
183 return NULL;
184 }
185
186 return pd;
187}
188#else
189static struct max8952_platform_data *max8952_parse_dt(struct device *dev)
190{
191 return NULL;
192}
193#endif
194
195static int max8952_pmic_probe(struct i2c_client *client,
196 const struct i2c_device_id *i2c_id)
197{
198 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
199 struct max8952_platform_data *pdata = client->dev.platform_data;
200 struct regulator_config config = { };
201 struct max8952_data *max8952;
202
203 int ret = 0, err = 0;
204
205 if (client->dev.of_node)
206 pdata = max8952_parse_dt(&client->dev);
207
208 if (!pdata) {
209 dev_err(&client->dev, "Require the platform data\n");
210 return -EINVAL;
211 }
212
213 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
214 return -EIO;
215
216 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data),
217 GFP_KERNEL);
218 if (!max8952)
219 return -ENOMEM;
220
221 max8952->client = client;
222 max8952->dev = &client->dev;
223 max8952->pdata = pdata;
224
225 config.dev = max8952->dev;
226 config.init_data = pdata->reg_data;
227 config.driver_data = max8952;
228 config.of_node = client->dev.of_node;
229
230 config.ena_gpio = pdata->gpio_en;
231 if (pdata->reg_data->constraints.boot_on)
232 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
233
234 max8952->rdev = regulator_register(®ulator, &config);
235
236 if (IS_ERR(max8952->rdev)) {
237 ret = PTR_ERR(max8952->rdev);
238 dev_err(max8952->dev, "regulator init failed (%d)\n", ret);
239 return ret;
240 }
241
242 max8952->vid0 = pdata->default_mode & 0x1;
243 max8952->vid1 = (pdata->default_mode >> 1) & 0x1;
244
245 if (gpio_is_valid(pdata->gpio_vid0) &&
246 gpio_is_valid(pdata->gpio_vid1)) {
247 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0"))
248 gpio_direction_output(pdata->gpio_vid0,
249 (pdata->default_mode) & 0x1);
250 else
251 err = 1;
252
253 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1"))
254 gpio_direction_output(pdata->gpio_vid1,
255 (pdata->default_mode >> 1) & 0x1);
256 else {
257 if (!err)
258 gpio_free(pdata->gpio_vid0);
259 err = 2;
260 }
261
262 } else
263 err = 3;
264
265 if (err) {
266 dev_warn(max8952->dev, "VID0/1 gpio invalid: "
267 "DVS not available.\n");
268 max8952->vid0 = 0;
269 max8952->vid1 = 0;
270
271 pdata->gpio_vid0 = -1;
272 pdata->gpio_vid1 = -1;
273
274
275 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60);
276
277 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1"
278 " do not have proper controls.\n");
279 } else {
280
281
282
283
284
285
286
287
288 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0);
289 }
290
291 max8952_write_reg(max8952, MAX8952_REG_MODE0,
292 (max8952_read_reg(max8952,
293 MAX8952_REG_MODE0) & 0xC0) |
294 (pdata->dvs_mode[0] & 0x3F));
295 max8952_write_reg(max8952, MAX8952_REG_MODE1,
296 (max8952_read_reg(max8952,
297 MAX8952_REG_MODE1) & 0xC0) |
298 (pdata->dvs_mode[1] & 0x3F));
299 max8952_write_reg(max8952, MAX8952_REG_MODE2,
300 (max8952_read_reg(max8952,
301 MAX8952_REG_MODE2) & 0xC0) |
302 (pdata->dvs_mode[2] & 0x3F));
303 max8952_write_reg(max8952, MAX8952_REG_MODE3,
304 (max8952_read_reg(max8952,
305 MAX8952_REG_MODE3) & 0xC0) |
306 (pdata->dvs_mode[3] & 0x3F));
307
308 max8952_write_reg(max8952, MAX8952_REG_SYNC,
309 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) |
310 ((pdata->sync_freq & 0x3) << 6));
311 max8952_write_reg(max8952, MAX8952_REG_RAMP,
312 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) |
313 ((pdata->ramp_speed & 0x7) << 5));
314
315 i2c_set_clientdata(client, max8952);
316
317 return 0;
318}
319
320static int max8952_pmic_remove(struct i2c_client *client)
321{
322 struct max8952_data *max8952 = i2c_get_clientdata(client);
323 struct max8952_platform_data *pdata = max8952->pdata;
324 struct regulator_dev *rdev = max8952->rdev;
325
326 regulator_unregister(rdev);
327
328 gpio_free(pdata->gpio_vid0);
329 gpio_free(pdata->gpio_vid1);
330 return 0;
331}
332
333static const struct i2c_device_id max8952_ids[] = {
334 { "max8952", 0 },
335 { },
336};
337MODULE_DEVICE_TABLE(i2c, max8952_ids);
338
339static struct i2c_driver max8952_pmic_driver = {
340 .probe = max8952_pmic_probe,
341 .remove = max8952_pmic_remove,
342 .driver = {
343 .name = "max8952",
344 .of_match_table = of_match_ptr(max8952_dt_match),
345 },
346 .id_table = max8952_ids,
347};
348
349static int __init max8952_pmic_init(void)
350{
351 return i2c_add_driver(&max8952_pmic_driver);
352}
353subsys_initcall(max8952_pmic_init);
354
355static void __exit max8952_pmic_exit(void)
356{
357 i2c_del_driver(&max8952_pmic_driver);
358}
359module_exit(max8952_pmic_exit);
360
361MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver");
362MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
363MODULE_LICENSE("GPL");
364
