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202f4f53 MH |
1 | /* |
2 | * max8952.c - Voltage and current regulation for the Maxim 8952 | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * MyungJoo Ham <myungjoo.ham@samsung.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | */ | |
21 | ||
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> | |
202f4f53 | 29 | #include <linux/gpio.h> |
d7a261c2 | 30 | #include <linux/gpio/consumer.h> |
202f4f53 | 31 | #include <linux/io.h> |
3ff4aa95 TF |
32 | #include <linux/of.h> |
33 | #include <linux/of_gpio.h> | |
34 | #include <linux/regulator/of_regulator.h> | |
202f4f53 MH |
35 | #include <linux/slab.h> |
36 | ||
37 | /* Registers */ | |
38 | enum { | |
39 | MAX8952_REG_MODE0, | |
40 | MAX8952_REG_MODE1, | |
41 | MAX8952_REG_MODE2, | |
42 | MAX8952_REG_MODE3, | |
43 | MAX8952_REG_CONTROL, | |
44 | MAX8952_REG_SYNC, | |
45 | MAX8952_REG_RAMP, | |
46 | MAX8952_REG_CHIP_ID1, | |
47 | MAX8952_REG_CHIP_ID2, | |
48 | }; | |
49 | ||
50 | struct max8952_data { | |
51 | struct i2c_client *client; | |
202f4f53 | 52 | struct max8952_platform_data *pdata; |
202f4f53 MH |
53 | |
54 | bool vid0; | |
55 | bool vid1; | |
202f4f53 MH |
56 | }; |
57 | ||
58 | static int max8952_read_reg(struct max8952_data *max8952, u8 reg) | |
59 | { | |
60 | int ret = i2c_smbus_read_byte_data(max8952->client, reg); | |
a5f8f963 | 61 | |
202f4f53 MH |
62 | if (ret > 0) |
63 | ret &= 0xff; | |
64 | ||
65 | return ret; | |
66 | } | |
67 | ||
68 | static 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 | ||
202f4f53 MH |
74 | static 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 | ||
b9b49af5 | 82 | return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000; |
202f4f53 MH |
83 | } |
84 | ||
b9b49af5 | 85 | static int max8952_get_voltage_sel(struct regulator_dev *rdev) |
202f4f53 MH |
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 | ||
b9b49af5 | 95 | return vid; |
202f4f53 MH |
96 | } |
97 | ||
6ea67d04 AL |
98 | static int max8952_set_voltage_sel(struct regulator_dev *rdev, |
99 | unsigned selector) | |
202f4f53 MH |
100 | { |
101 | struct max8952_data *max8952 = rdev_get_drvdata(rdev); | |
202f4f53 MH |
102 | |
103 | if (!gpio_is_valid(max8952->pdata->gpio_vid0) || | |
e2cf3137 | 104 | !gpio_is_valid(max8952->pdata->gpio_vid1)) { |
202f4f53 MH |
105 | /* DVS not supported */ |
106 | return -EPERM; | |
107 | } | |
108 | ||
6ea67d04 AL |
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); | |
202f4f53 MH |
113 | |
114 | return 0; | |
115 | } | |
116 | ||
6e09f4af | 117 | static const struct regulator_ops max8952_ops = { |
202f4f53 | 118 | .list_voltage = max8952_list_voltage, |
b9b49af5 | 119 | .get_voltage_sel = max8952_get_voltage_sel, |
6ea67d04 | 120 | .set_voltage_sel = max8952_set_voltage_sel, |
202f4f53 MH |
121 | }; |
122 | ||
bd6ff0d6 | 123 | static const struct regulator_desc regulator = { |
202f4f53 MH |
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 | ||
3ff4aa95 | 132 | #ifdef CONFIG_OF |
cfe6e333 | 133 | static const struct of_device_id max8952_dt_match[] = { |
3ff4aa95 TF |
134 | { .compatible = "maxim,max8952" }, |
135 | {}, | |
136 | }; | |
137 | MODULE_DEVICE_TABLE(of, max8952_dt_match); | |
138 | ||
139 | static 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); | |
7752d964 | 147 | if (!pd) |
3ff4aa95 | 148 | return NULL; |
3ff4aa95 TF |
149 | |
150 | pd->gpio_vid0 = of_get_named_gpio(np, "max8952,vid-gpios", 0); | |
151 | pd->gpio_vid1 = of_get_named_gpio(np, "max8952,vid-gpios", 1); | |
3ff4aa95 TF |
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 | ||
072e78b1 | 177 | pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator); |
3ff4aa95 TF |
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 | |
186 | static struct max8952_platform_data *max8952_parse_dt(struct device *dev) | |
187 | { | |
188 | return NULL; | |
189 | } | |
190 | #endif | |
191 | ||
a5023574 | 192 | static int max8952_pmic_probe(struct i2c_client *client, |
202f4f53 MH |
193 | const struct i2c_device_id *i2c_id) |
194 | { | |
195 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
dff91d0b | 196 | struct max8952_platform_data *pdata = dev_get_platdata(&client->dev); |
c172708d | 197 | struct regulator_config config = { }; |
202f4f53 | 198 | struct max8952_data *max8952; |
b874f41c | 199 | struct regulator_dev *rdev; |
d7a261c2 LW |
200 | struct gpio_desc *gpiod; |
201 | enum gpiod_flags gflags; | |
202f4f53 MH |
202 | |
203 | int ret = 0, err = 0; | |
204 | ||
3ff4aa95 TF |
205 | if (client->dev.of_node) |
206 | pdata = max8952_parse_dt(&client->dev); | |
207 | ||
202f4f53 MH |
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 | ||
372de4aa AL |
216 | max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data), |
217 | GFP_KERNEL); | |
202f4f53 MH |
218 | if (!max8952) |
219 | return -ENOMEM; | |
220 | ||
221 | max8952->client = client; | |
202f4f53 | 222 | max8952->pdata = pdata; |
202f4f53 | 223 | |
b874f41c | 224 | config.dev = &client->dev; |
3ec6eb9c | 225 | config.init_data = pdata->reg_data; |
c172708d | 226 | config.driver_data = max8952; |
71622e15 | 227 | config.of_node = client->dev.of_node; |
c172708d | 228 | |
3ec6eb9c | 229 | if (pdata->reg_data->constraints.boot_on) |
d7a261c2 LW |
230 | gflags = GPIOD_OUT_HIGH; |
231 | else | |
232 | gflags = GPIOD_OUT_LOW; | |
63239e4b | 233 | gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; |
894077d5 LW |
234 | /* |
235 | * Do not use devm* here: the regulator core takes over the | |
236 | * lifecycle management of the GPIO descriptor. | |
237 | */ | |
238 | gpiod = gpiod_get_optional(&client->dev, | |
239 | "max8952,en", | |
240 | gflags); | |
d7a261c2 LW |
241 | if (IS_ERR(gpiod)) |
242 | return PTR_ERR(gpiod); | |
243 | if (gpiod) | |
244 | config.ena_gpiod = gpiod; | |
b669e0ad | 245 | |
b874f41c | 246 | rdev = devm_regulator_register(&client->dev, ®ulator, &config); |
b874f41c KK |
247 | if (IS_ERR(rdev)) { |
248 | ret = PTR_ERR(rdev); | |
249 | dev_err(&client->dev, "regulator init failed (%d)\n", ret); | |
372de4aa | 250 | return ret; |
da05738e | 251 | } |
202f4f53 | 252 | |
c8237f01 AL |
253 | max8952->vid0 = pdata->default_mode & 0x1; |
254 | max8952->vid1 = (pdata->default_mode >> 1) & 0x1; | |
202f4f53 | 255 | |
202f4f53 MH |
256 | if (gpio_is_valid(pdata->gpio_vid0) && |
257 | gpio_is_valid(pdata->gpio_vid1)) { | |
d7da152c AL |
258 | unsigned long gpio_flags; |
259 | ||
260 | gpio_flags = max8952->vid0 ? | |
261 | GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; | |
262 | if (devm_gpio_request_one(&client->dev, pdata->gpio_vid0, | |
263 | gpio_flags, "MAX8952 VID0")) | |
202f4f53 MH |
264 | err = 1; |
265 | ||
d7da152c AL |
266 | gpio_flags = max8952->vid1 ? |
267 | GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; | |
268 | if (devm_gpio_request_one(&client->dev, pdata->gpio_vid1, | |
269 | gpio_flags, "MAX8952 VID1")) | |
202f4f53 | 270 | err = 2; |
202f4f53 MH |
271 | } else |
272 | err = 3; | |
273 | ||
274 | if (err) { | |
b874f41c | 275 | dev_warn(&client->dev, "VID0/1 gpio invalid: " |
25985edc | 276 | "DVS not available.\n"); |
202f4f53 MH |
277 | max8952->vid0 = 0; |
278 | max8952->vid1 = 0; | |
279 | /* Mark invalid */ | |
280 | pdata->gpio_vid0 = -1; | |
281 | pdata->gpio_vid1 = -1; | |
282 | ||
283 | /* Disable Pulldown of EN only */ | |
284 | max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60); | |
285 | ||
b874f41c | 286 | dev_err(&client->dev, "DVS modes disabled because VID0 and VID1" |
202f4f53 MH |
287 | " do not have proper controls.\n"); |
288 | } else { | |
289 | /* | |
290 | * Disable Pulldown on EN, VID0, VID1 to reduce | |
291 | * leakage current of MAX8952 assuming that MAX8952 | |
292 | * is turned on (EN==1). Note that without having VID0/1 | |
293 | * properly connected, turning pulldown off can be | |
294 | * problematic. Thus, turn this off only when they are | |
295 | * controllable by GPIO. | |
296 | */ | |
297 | max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0); | |
298 | } | |
299 | ||
300 | max8952_write_reg(max8952, MAX8952_REG_MODE0, | |
301 | (max8952_read_reg(max8952, | |
302 | MAX8952_REG_MODE0) & 0xC0) | | |
303 | (pdata->dvs_mode[0] & 0x3F)); | |
304 | max8952_write_reg(max8952, MAX8952_REG_MODE1, | |
305 | (max8952_read_reg(max8952, | |
306 | MAX8952_REG_MODE1) & 0xC0) | | |
307 | (pdata->dvs_mode[1] & 0x3F)); | |
308 | max8952_write_reg(max8952, MAX8952_REG_MODE2, | |
309 | (max8952_read_reg(max8952, | |
310 | MAX8952_REG_MODE2) & 0xC0) | | |
311 | (pdata->dvs_mode[2] & 0x3F)); | |
312 | max8952_write_reg(max8952, MAX8952_REG_MODE3, | |
313 | (max8952_read_reg(max8952, | |
314 | MAX8952_REG_MODE3) & 0xC0) | | |
315 | (pdata->dvs_mode[3] & 0x3F)); | |
316 | ||
317 | max8952_write_reg(max8952, MAX8952_REG_SYNC, | |
318 | (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) | | |
319 | ((pdata->sync_freq & 0x3) << 6)); | |
320 | max8952_write_reg(max8952, MAX8952_REG_RAMP, | |
321 | (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) | | |
322 | ((pdata->ramp_speed & 0x7) << 5)); | |
323 | ||
324 | i2c_set_clientdata(client, max8952); | |
325 | ||
da05738e | 326 | return 0; |
202f4f53 MH |
327 | } |
328 | ||
202f4f53 MH |
329 | static const struct i2c_device_id max8952_ids[] = { |
330 | { "max8952", 0 }, | |
331 | { }, | |
332 | }; | |
333 | MODULE_DEVICE_TABLE(i2c, max8952_ids); | |
334 | ||
335 | static struct i2c_driver max8952_pmic_driver = { | |
336 | .probe = max8952_pmic_probe, | |
202f4f53 MH |
337 | .driver = { |
338 | .name = "max8952", | |
3ff4aa95 | 339 | .of_match_table = of_match_ptr(max8952_dt_match), |
202f4f53 MH |
340 | }, |
341 | .id_table = max8952_ids, | |
342 | }; | |
343 | ||
344 | static int __init max8952_pmic_init(void) | |
345 | { | |
346 | return i2c_add_driver(&max8952_pmic_driver); | |
347 | } | |
348 | subsys_initcall(max8952_pmic_init); | |
349 | ||
350 | static void __exit max8952_pmic_exit(void) | |
351 | { | |
352 | i2c_del_driver(&max8952_pmic_driver); | |
353 | } | |
354 | module_exit(max8952_pmic_exit); | |
355 | ||
356 | MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); | |
357 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
358 | MODULE_LICENSE("GPL"); |