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5928f538 LD |
1 | /* |
2 | * max8973-regulator.c -- Maxim max8973 | |
3 | * | |
4 | * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator. | |
5 | * | |
6 | * Copyright (c) 2012, NVIDIA Corporation. | |
7 | * | |
8 | * Author: Laxman Dewangan <ldewangan@nvidia.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation version 2. | |
13 | * | |
14 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, | |
15 | * whether express or implied; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
22 | * 02111-1307, USA | |
23 | */ | |
24 | ||
25 | #include <linux/kernel.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/err.h> | |
29 | #include <linux/platform_device.h> | |
30 | #include <linux/regulator/driver.h> | |
31 | #include <linux/regulator/machine.h> | |
32 | #include <linux/regulator/max8973-regulator.h> | |
33 | #include <linux/gpio.h> | |
34 | #include <linux/i2c.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/regmap.h> | |
37 | ||
38 | /* Register definitions */ | |
39 | #define MAX8973_VOUT 0x0 | |
40 | #define MAX8973_VOUT_DVS 0x1 | |
41 | #define MAX8973_CONTROL1 0x2 | |
42 | #define MAX8973_CONTROL2 0x3 | |
43 | #define MAX8973_CHIPID1 0x4 | |
44 | #define MAX8973_CHIPID2 0x5 | |
45 | ||
46 | #define MAX8973_MAX_VOUT_REG 2 | |
47 | ||
48 | /* MAX8973_VOUT */ | |
49 | #define MAX8973_VOUT_ENABLE BIT(7) | |
50 | #define MAX8973_VOUT_MASK 0x7F | |
51 | ||
52 | /* MAX8973_VOUT_DVS */ | |
53 | #define MAX8973_DVS_VOUT_MASK 0x7F | |
54 | ||
55 | /* MAX8973_CONTROL1 */ | |
56 | #define MAX8973_SNS_ENABLE BIT(7) | |
57 | #define MAX8973_FPWM_EN_M BIT(6) | |
58 | #define MAX8973_NFSR_ENABLE BIT(5) | |
59 | #define MAX8973_AD_ENABLE BIT(4) | |
60 | #define MAX8973_BIAS_ENABLE BIT(3) | |
61 | #define MAX8973_FREQSHIFT_9PER BIT(2) | |
62 | ||
63 | #define MAX8973_RAMP_12mV_PER_US 0x0 | |
64 | #define MAX8973_RAMP_25mV_PER_US 0x1 | |
65 | #define MAX8973_RAMP_50mV_PER_US 0x2 | |
66 | #define MAX8973_RAMP_200mV_PER_US 0x3 | |
67 | ||
68 | /* MAX8973_CONTROL2 */ | |
69 | #define MAX8973_WDTMR_ENABLE BIT(6) | |
70 | #define MAX8973_DISCH_ENBABLE BIT(5) | |
71 | #define MAX8973_FT_ENABLE BIT(4) | |
72 | ||
73 | #define MAX8973_CKKADV_TRIP_DISABLE 0xC | |
74 | #define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0 | |
75 | #define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4 | |
76 | #define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8 | |
77 | #define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000 | |
78 | ||
79 | #define MAX8973_INDUCTOR_MIN_30_PER 0x0 | |
80 | #define MAX8973_INDUCTOR_NOMINAL 0x1 | |
81 | #define MAX8973_INDUCTOR_PLUS_30_PER 0x2 | |
82 | #define MAX8973_INDUCTOR_PLUS_60_PER 0x3 | |
83 | #define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000 | |
84 | ||
85 | #define MAX8973_MIN_VOLATGE 606250 | |
86 | #define MAX8973_MAX_VOLATGE 1400000 | |
87 | #define MAX8973_VOLATGE_STEP 6250 | |
88 | #define MAX8973_BUCK_N_VOLTAGE 0x80 | |
89 | ||
90 | /* Maxim 8973 chip information */ | |
91 | struct max8973_chip { | |
92 | struct device *dev; | |
93 | struct regulator_desc desc; | |
94 | struct regulator_dev *rdev; | |
95 | struct regmap *regmap; | |
96 | bool enable_external_control; | |
97 | int dvs_gpio; | |
98 | int lru_index[MAX8973_MAX_VOUT_REG]; | |
99 | int curr_vout_val[MAX8973_MAX_VOUT_REG]; | |
100 | int curr_vout_reg; | |
101 | int curr_gpio_val; | |
102 | bool valid_dvs_gpio; | |
103 | }; | |
104 | ||
105 | /* | |
106 | * find_voltage_set_register: Find new voltage configuration register (VOUT). | |
107 | * The finding of the new VOUT register will be based on the LRU mechanism. | |
108 | * Each VOUT register will have different voltage configured . This | |
109 | * Function will look if any of the VOUT register have requested voltage set | |
110 | * or not. | |
111 | * - If it is already there then it will make that register as most | |
112 | * recently used and return as found so that caller need not to set | |
113 | * the VOUT register but need to set the proper gpios to select this | |
114 | * VOUT register. | |
115 | * - If requested voltage is not found then it will use the least | |
116 | * recently mechanism to get new VOUT register for new configuration | |
117 | * and will return not_found so that caller need to set new VOUT | |
118 | * register and then gpios (both). | |
119 | */ | |
120 | static bool find_voltage_set_register(struct max8973_chip *tps, | |
121 | int req_vsel, int *vout_reg, int *gpio_val) | |
122 | { | |
123 | int i; | |
124 | bool found = false; | |
125 | int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1]; | |
126 | int found_index = MAX8973_MAX_VOUT_REG - 1; | |
127 | ||
128 | for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) { | |
129 | if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) { | |
130 | new_vout_reg = tps->lru_index[i]; | |
131 | found_index = i; | |
132 | found = true; | |
133 | goto update_lru_index; | |
134 | } | |
135 | } | |
136 | ||
137 | update_lru_index: | |
138 | for (i = found_index; i > 0; i--) | |
139 | tps->lru_index[i] = tps->lru_index[i - 1]; | |
140 | ||
141 | tps->lru_index[0] = new_vout_reg; | |
142 | *gpio_val = new_vout_reg; | |
143 | *vout_reg = MAX8973_VOUT + new_vout_reg; | |
144 | return found; | |
145 | } | |
146 | ||
147 | static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev) | |
148 | { | |
149 | struct max8973_chip *max = rdev_get_drvdata(rdev); | |
150 | unsigned int data; | |
151 | int ret; | |
152 | ||
153 | ret = regmap_read(max->regmap, max->curr_vout_reg, &data); | |
154 | if (ret < 0) { | |
155 | dev_err(max->dev, "register %d read failed, err = %d\n", | |
156 | max->curr_vout_reg, ret); | |
157 | return ret; | |
158 | } | |
159 | return data & MAX8973_VOUT_MASK; | |
160 | } | |
161 | ||
162 | static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev, | |
163 | unsigned vsel) | |
164 | { | |
165 | struct max8973_chip *max = rdev_get_drvdata(rdev); | |
166 | int ret; | |
167 | bool found = false; | |
168 | int vout_reg = max->curr_vout_reg; | |
169 | int gpio_val = max->curr_gpio_val; | |
170 | ||
171 | /* | |
172 | * If gpios are available to select the VOUT register then least | |
173 | * recently used register for new configuration. | |
174 | */ | |
175 | if (max->valid_dvs_gpio) | |
176 | found = find_voltage_set_register(max, vsel, | |
177 | &vout_reg, &gpio_val); | |
178 | ||
179 | if (!found) { | |
180 | ret = regmap_update_bits(max->regmap, vout_reg, | |
181 | MAX8973_VOUT_MASK, vsel); | |
182 | if (ret < 0) { | |
183 | dev_err(max->dev, "register %d update failed, err %d\n", | |
184 | vout_reg, ret); | |
185 | return ret; | |
186 | } | |
187 | max->curr_vout_reg = vout_reg; | |
188 | max->curr_vout_val[gpio_val] = vsel; | |
189 | } | |
190 | ||
191 | /* Select proper VOUT register vio gpios */ | |
192 | if (max->valid_dvs_gpio) { | |
193 | gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1); | |
194 | max->curr_gpio_val = gpio_val; | |
195 | } | |
196 | return 0; | |
197 | } | |
198 | ||
199 | static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode) | |
200 | { | |
201 | struct max8973_chip *max = rdev_get_drvdata(rdev); | |
202 | int ret; | |
203 | int pwm; | |
204 | ||
205 | /* Enable force PWM mode in FAST mode only. */ | |
206 | switch (mode) { | |
207 | case REGULATOR_MODE_FAST: | |
208 | pwm = MAX8973_FPWM_EN_M; | |
209 | break; | |
210 | ||
211 | case REGULATOR_MODE_NORMAL: | |
212 | pwm = 0; | |
213 | break; | |
214 | ||
215 | default: | |
216 | return -EINVAL; | |
217 | } | |
218 | ||
219 | ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1, | |
220 | MAX8973_FPWM_EN_M, pwm); | |
221 | if (ret < 0) | |
222 | dev_err(max->dev, "register %d update failed, err %d\n", | |
223 | MAX8973_CONTROL1, ret); | |
224 | return ret; | |
225 | } | |
226 | ||
227 | static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev) | |
228 | { | |
229 | struct max8973_chip *max = rdev_get_drvdata(rdev); | |
230 | unsigned int data; | |
231 | int ret; | |
232 | ||
233 | ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data); | |
234 | if (ret < 0) { | |
235 | dev_err(max->dev, "register %d read failed, err %d\n", | |
236 | MAX8973_CONTROL1, ret); | |
237 | return ret; | |
238 | } | |
239 | return (data & MAX8973_FPWM_EN_M) ? | |
240 | REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL; | |
241 | } | |
242 | ||
243 | static struct regulator_ops max8973_dcdc_ops = { | |
244 | .get_voltage_sel = max8973_dcdc_get_voltage_sel, | |
245 | .set_voltage_sel = max8973_dcdc_set_voltage_sel, | |
246 | .list_voltage = regulator_list_voltage_linear, | |
247 | .set_mode = max8973_dcdc_set_mode, | |
248 | .get_mode = max8973_dcdc_get_mode, | |
249 | }; | |
250 | ||
251 | static int __devinit max8973_init_dcdc(struct max8973_chip *max, | |
252 | struct max8973_regulator_platform_data *pdata) | |
253 | { | |
254 | int ret; | |
255 | uint8_t control1 = 0; | |
256 | uint8_t control2 = 0; | |
257 | ||
258 | if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE) | |
259 | control1 |= MAX8973_SNS_ENABLE; | |
260 | ||
261 | if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE)) | |
262 | control1 |= MAX8973_NFSR_ENABLE; | |
263 | ||
264 | if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE) | |
265 | control1 |= MAX8973_AD_ENABLE; | |
266 | ||
267 | if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE) | |
268 | control1 |= MAX8973_BIAS_ENABLE; | |
269 | ||
270 | if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE) | |
271 | control1 |= MAX8973_FREQSHIFT_9PER; | |
272 | ||
273 | /* Set ramp delay */ | |
274 | if (pdata->reg_init_data && | |
275 | pdata->reg_init_data->constraints.ramp_delay) { | |
276 | if (pdata->reg_init_data->constraints.ramp_delay < 25000) | |
277 | control1 = MAX8973_RAMP_12mV_PER_US; | |
278 | else if (pdata->reg_init_data->constraints.ramp_delay < 50000) | |
279 | control1 = MAX8973_RAMP_25mV_PER_US; | |
280 | else if (pdata->reg_init_data->constraints.ramp_delay < 200000) | |
281 | control1 = MAX8973_RAMP_50mV_PER_US; | |
282 | else | |
283 | control1 = MAX8973_RAMP_200mV_PER_US; | |
284 | } else { | |
285 | control1 = MAX8973_RAMP_12mV_PER_US; | |
286 | max->desc.ramp_delay = 12500; | |
287 | } | |
288 | ||
289 | if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE)) | |
290 | control2 |= MAX8973_DISCH_ENBABLE; | |
291 | ||
292 | /* Clock advance trip configuration */ | |
293 | switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) { | |
294 | case MAX8973_CONTROL_CLKADV_TRIP_DISABLED: | |
295 | control2 |= MAX8973_CKKADV_TRIP_DISABLE; | |
296 | break; | |
297 | ||
298 | case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US: | |
299 | control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US; | |
300 | break; | |
301 | ||
302 | case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US: | |
303 | control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US; | |
304 | break; | |
305 | ||
306 | case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS: | |
307 | control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS; | |
308 | break; | |
309 | } | |
310 | ||
311 | /* Configure inductor value */ | |
312 | switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) { | |
313 | case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL: | |
314 | control2 |= MAX8973_INDUCTOR_NOMINAL; | |
315 | break; | |
316 | ||
317 | case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER: | |
318 | control2 |= MAX8973_INDUCTOR_MIN_30_PER; | |
319 | break; | |
320 | ||
321 | case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER: | |
322 | control2 |= MAX8973_INDUCTOR_PLUS_30_PER; | |
323 | break; | |
324 | ||
325 | case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER: | |
326 | control2 |= MAX8973_INDUCTOR_PLUS_60_PER; | |
327 | break; | |
328 | } | |
329 | ||
330 | ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1); | |
331 | if (ret < 0) { | |
332 | dev_err(max->dev, "register %d write failed, err = %d", | |
333 | MAX8973_CONTROL1, ret); | |
334 | return ret; | |
335 | } | |
336 | ||
337 | ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2); | |
338 | if (ret < 0) { | |
339 | dev_err(max->dev, "register %d write failed, err = %d", | |
340 | MAX8973_CONTROL2, ret); | |
341 | return ret; | |
342 | } | |
343 | ||
344 | /* If external control is enabled then disable EN bit */ | |
345 | if (max->enable_external_control) { | |
346 | ret = regmap_update_bits(max->regmap, MAX8973_VOUT, | |
347 | MAX8973_VOUT_ENABLE, 0); | |
348 | if (ret < 0) | |
349 | dev_err(max->dev, "register %d update failed, err = %d", | |
350 | MAX8973_VOUT, ret); | |
351 | } | |
352 | return ret; | |
353 | } | |
354 | ||
355 | static const struct regmap_config max8973_regmap_config = { | |
356 | .reg_bits = 8, | |
357 | .val_bits = 8, | |
358 | .max_register = MAX8973_CHIPID2, | |
359 | .cache_type = REGCACHE_RBTREE, | |
360 | }; | |
361 | ||
362 | static int __devinit max8973_probe(struct i2c_client *client, | |
363 | const struct i2c_device_id *id) | |
364 | { | |
365 | struct max8973_regulator_platform_data *pdata; | |
366 | struct regulator_config config = { }; | |
367 | struct regulator_dev *rdev; | |
368 | struct max8973_chip *max; | |
369 | int ret; | |
370 | ||
371 | pdata = client->dev.platform_data; | |
372 | if (!pdata) { | |
373 | dev_err(&client->dev, "No Platform data"); | |
374 | return -EIO; | |
375 | } | |
376 | ||
377 | max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL); | |
378 | if (!max) { | |
379 | dev_err(&client->dev, "Memory allocation for max failed\n"); | |
380 | return -ENOMEM; | |
381 | } | |
382 | ||
383 | max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config); | |
384 | if (IS_ERR(max->regmap)) { | |
385 | ret = PTR_ERR(max->regmap); | |
386 | dev_err(&client->dev, "regmap init failed, err %d\n", ret); | |
387 | return ret; | |
388 | } | |
389 | ||
390 | i2c_set_clientdata(client, max); | |
391 | max->dev = &client->dev; | |
392 | max->desc.name = id->name; | |
393 | max->desc.id = 0; | |
394 | max->desc.ops = &max8973_dcdc_ops; | |
395 | max->desc.type = REGULATOR_VOLTAGE; | |
396 | max->desc.owner = THIS_MODULE; | |
397 | max->desc.min_uV = MAX8973_MIN_VOLATGE; | |
398 | max->desc.uV_step = MAX8973_VOLATGE_STEP; | |
399 | max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE; | |
400 | ||
56968658 | 401 | if (!pdata->enable_ext_control) { |
5928f538 LD |
402 | max->desc.enable_reg = MAX8973_VOUT; |
403 | max->desc.enable_mask = MAX8973_VOUT_ENABLE; | |
e05f70c2 | 404 | max8973_dcdc_ops.enable = regulator_enable_regmap; |
5928f538 LD |
405 | max8973_dcdc_ops.disable = regulator_disable_regmap; |
406 | max8973_dcdc_ops.is_enabled = regulator_is_enabled_regmap; | |
407 | } | |
408 | ||
409 | max->enable_external_control = pdata->enable_ext_control; | |
410 | max->dvs_gpio = pdata->dvs_gpio; | |
411 | max->curr_gpio_val = pdata->dvs_def_state; | |
412 | max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state; | |
413 | max->lru_index[0] = max->curr_vout_reg; | |
414 | max->valid_dvs_gpio = false; | |
415 | ||
416 | if (gpio_is_valid(max->dvs_gpio)) { | |
417 | int gpio_flags; | |
418 | int i; | |
419 | ||
420 | gpio_flags = (pdata->dvs_def_state) ? | |
421 | GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; | |
422 | ret = devm_gpio_request_one(&client->dev, max->dvs_gpio, | |
423 | gpio_flags, "max8973-dvs"); | |
424 | if (ret) { | |
425 | dev_err(&client->dev, | |
426 | "gpio_request for gpio %d failed, err = %d\n", | |
427 | max->dvs_gpio, ret); | |
428 | return ret; | |
429 | } | |
430 | max->valid_dvs_gpio = true; | |
431 | ||
432 | /* | |
433 | * Initialize the lru index with vout_reg id | |
434 | * The index 0 will be most recently used and | |
435 | * set with the max->curr_vout_reg */ | |
436 | for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) | |
437 | max->lru_index[i] = i; | |
438 | max->lru_index[0] = max->curr_vout_reg; | |
439 | max->lru_index[max->curr_vout_reg] = 0; | |
440 | } | |
441 | ||
442 | ret = max8973_init_dcdc(max, pdata); | |
443 | if (ret < 0) { | |
444 | dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret); | |
445 | return ret; | |
446 | } | |
447 | ||
448 | config.dev = &client->dev; | |
449 | config.init_data = pdata->reg_init_data; | |
450 | config.driver_data = max; | |
451 | config.of_node = client->dev.of_node; | |
452 | config.regmap = max->regmap; | |
453 | ||
454 | /* Register the regulators */ | |
455 | rdev = regulator_register(&max->desc, &config); | |
456 | if (IS_ERR(rdev)) { | |
457 | ret = PTR_ERR(rdev); | |
458 | dev_err(max->dev, "regulator register failed, err %d\n", ret); | |
459 | return ret; | |
460 | } | |
461 | ||
462 | max->rdev = rdev; | |
463 | return 0; | |
464 | } | |
465 | ||
466 | static int __devexit max8973_remove(struct i2c_client *client) | |
467 | { | |
468 | struct max8973_chip *max = i2c_get_clientdata(client); | |
469 | ||
470 | regulator_unregister(max->rdev); | |
471 | return 0; | |
472 | } | |
473 | ||
474 | static const struct i2c_device_id max8973_id[] = { | |
475 | {.name = "max8973",}, | |
476 | {}, | |
477 | }; | |
478 | ||
479 | MODULE_DEVICE_TABLE(i2c, max8973_id); | |
480 | ||
481 | static struct i2c_driver max8973_i2c_driver = { | |
482 | .driver = { | |
483 | .name = "max8973", | |
484 | .owner = THIS_MODULE, | |
485 | }, | |
486 | .probe = max8973_probe, | |
487 | .remove = __devexit_p(max8973_remove), | |
488 | .id_table = max8973_id, | |
489 | }; | |
490 | ||
491 | static int __init max8973_init(void) | |
492 | { | |
493 | return i2c_add_driver(&max8973_i2c_driver); | |
494 | } | |
495 | subsys_initcall(max8973_init); | |
496 | ||
497 | static void __exit max8973_cleanup(void) | |
498 | { | |
499 | i2c_del_driver(&max8973_i2c_driver); | |
500 | } | |
501 | module_exit(max8973_cleanup); | |
502 | ||
503 | MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); | |
504 | MODULE_DESCRIPTION("MAX8973 voltage regulator driver"); | |
505 | MODULE_LICENSE("GPL v2"); |