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37b918a0 TH |
1 | /* |
2 | * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | */ | |
14 | #include <linux/i2c.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/of.h> | |
20 | #include <linux/regmap.h> | |
21 | #include <linux/regulator/driver.h> | |
22 | #include <linux/regulator/machine.h> | |
23 | #include <linux/regulator/of_regulator.h> | |
24 | ||
25 | #define DRIVER_NAME "ltc3676" | |
26 | ||
27 | /* LTC3676 Registers */ | |
28 | #define LTC3676_BUCK1 0x01 | |
29 | #define LTC3676_BUCK2 0x02 | |
30 | #define LTC3676_BUCK3 0x03 | |
31 | #define LTC3676_BUCK4 0x04 | |
32 | #define LTC3676_LDOA 0x05 | |
33 | #define LTC3676_LDOB 0x06 | |
34 | #define LTC3676_SQD1 0x07 | |
35 | #define LTC3676_SQD2 0x08 | |
36 | #define LTC3676_CNTRL 0x09 | |
37 | #define LTC3676_DVB1A 0x0A | |
38 | #define LTC3676_DVB1B 0x0B | |
39 | #define LTC3676_DVB2A 0x0C | |
40 | #define LTC3676_DVB2B 0x0D | |
41 | #define LTC3676_DVB3A 0x0E | |
42 | #define LTC3676_DVB3B 0x0F | |
43 | #define LTC3676_DVB4A 0x10 | |
44 | #define LTC3676_DVB4B 0x11 | |
45 | #define LTC3676_MSKIRQ 0x12 | |
46 | #define LTC3676_MSKPG 0x13 | |
47 | #define LTC3676_USER 0x14 | |
48 | #define LTC3676_IRQSTAT 0x15 | |
49 | #define LTC3676_PGSTATL 0x16 | |
50 | #define LTC3676_PGSTATRT 0x17 | |
51 | #define LTC3676_HRST 0x1E | |
52 | #define LTC3676_CLIRQ 0x1F | |
53 | ||
54 | #define LTC3676_DVBxA_REF_SELECT BIT(5) | |
55 | ||
56 | #define LTC3676_IRQSTAT_PGOOD_TIMEOUT BIT(3) | |
57 | #define LTC3676_IRQSTAT_UNDERVOLT_WARN BIT(4) | |
58 | #define LTC3676_IRQSTAT_UNDERVOLT_FAULT BIT(5) | |
59 | #define LTC3676_IRQSTAT_THERMAL_WARN BIT(6) | |
60 | #define LTC3676_IRQSTAT_THERMAL_FAULT BIT(7) | |
61 | ||
62 | enum ltc3676_reg { | |
63 | LTC3676_SW1, | |
64 | LTC3676_SW2, | |
65 | LTC3676_SW3, | |
66 | LTC3676_SW4, | |
67 | LTC3676_LDO1, | |
68 | LTC3676_LDO2, | |
69 | LTC3676_LDO3, | |
70 | LTC3676_LDO4, | |
71 | LTC3676_NUM_REGULATORS, | |
72 | }; | |
73 | ||
74 | struct ltc3676 { | |
75 | struct regmap *regmap; | |
76 | struct device *dev; | |
77 | struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS]; | |
78 | struct regulator_dev *regulators[LTC3676_NUM_REGULATORS]; | |
79 | }; | |
80 | ||
81 | static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV) | |
82 | { | |
83 | struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev); | |
84 | struct device *dev = ltc3676->dev; | |
85 | int dcdc = rdev_get_id(rdev); | |
86 | int sel; | |
87 | ||
88 | dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV); | |
89 | sel = regulator_map_voltage_linear(rdev, uV, uV); | |
90 | if (sel < 0) | |
91 | return sel; | |
92 | ||
93 | /* DVBB register follows right after the corresponding DVBA register */ | |
94 | return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1, | |
95 | rdev->desc->vsel_mask, sel); | |
96 | } | |
97 | ||
98 | static int ltc3676_set_suspend_mode(struct regulator_dev *rdev, | |
99 | unsigned int mode) | |
100 | { | |
101 | struct ltc3676 *ltc3676= rdev_get_drvdata(rdev); | |
102 | struct device *dev = ltc3676->dev; | |
103 | int mask, val; | |
104 | int dcdc = rdev_get_id(rdev); | |
105 | ||
106 | dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode); | |
107 | ||
108 | mask = LTC3676_DVBxA_REF_SELECT; | |
109 | switch (mode) { | |
110 | case REGULATOR_MODE_STANDBY: | |
111 | val = 0; /* select DVBxA */ | |
112 | break; | |
113 | case REGULATOR_MODE_NORMAL: | |
114 | val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */ | |
115 | break; | |
116 | default: | |
117 | dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n", | |
118 | rdev->desc->name, mode); | |
119 | return -EINVAL; | |
120 | } | |
121 | ||
122 | return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg, | |
123 | mask, val); | |
124 | } | |
125 | ||
126 | static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2) | |
127 | { | |
128 | uint64_t tmp; | |
129 | if (uV == 0) | |
130 | return 0; | |
131 | tmp = (uint64_t)uV * r1; | |
132 | do_div(tmp, r2); | |
133 | return uV + (unsigned int)tmp; | |
134 | } | |
135 | ||
136 | static int ltc3676_of_parse_cb(struct device_node *np, | |
137 | const struct regulator_desc *desc, | |
138 | struct regulator_config *config) | |
139 | { | |
140 | struct ltc3676 *ltc3676 = config->driver_data; | |
141 | struct regulator_desc *rdesc = <c3676->regulator_descs[desc->id]; | |
142 | u32 r[2]; | |
143 | int ret; | |
144 | ||
145 | /* LDO3 has a fixed output */ | |
146 | if (desc->id == LTC3676_LDO3) | |
147 | return 0; | |
148 | ||
149 | ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2); | |
150 | if (ret) { | |
151 | dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n", | |
152 | ret); | |
153 | return ret; | |
154 | } | |
155 | ||
156 | rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]); | |
157 | rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]); | |
158 | rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]); | |
159 | ||
160 | return 0; | |
161 | } | |
162 | ||
163 | /* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */ | |
f9e93acc | 164 | static const struct regulator_ops ltc3676_linear_regulator_ops = { |
37b918a0 TH |
165 | .enable = regulator_enable_regmap, |
166 | .disable = regulator_disable_regmap, | |
167 | .is_enabled = regulator_is_enabled_regmap, | |
168 | .list_voltage = regulator_list_voltage_linear, | |
169 | .set_voltage_sel = regulator_set_voltage_sel_regmap, | |
170 | .get_voltage_sel = regulator_get_voltage_sel_regmap, | |
171 | .set_suspend_voltage = ltc3676_set_suspend_voltage, | |
172 | .set_suspend_mode = ltc3676_set_suspend_mode, | |
173 | }; | |
174 | ||
175 | /* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */ | |
f9e93acc | 176 | static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = { |
37b918a0 TH |
177 | }; |
178 | ||
179 | /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */ | |
f9e93acc | 180 | static const struct regulator_ops ltc3676_fixed_regulator_ops = { |
37b918a0 TH |
181 | .enable = regulator_enable_regmap, |
182 | .disable = regulator_disable_regmap, | |
183 | .is_enabled = regulator_is_enabled_regmap, | |
184 | }; | |
185 | ||
186 | #define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask) \ | |
187 | [LTC3676_ ## _id] = { \ | |
188 | .name = #_name, \ | |
189 | .of_match = of_match_ptr(#_name), \ | |
190 | .regulators_node = of_match_ptr("regulators"), \ | |
191 | .of_parse_cb = ltc3676_of_parse_cb, \ | |
192 | .n_voltages = (dvb_mask) + 1, \ | |
193 | .min_uV = (dvba_reg) ? 412500 : 0, \ | |
194 | .uV_step = (dvba_reg) ? 12500 : 0, \ | |
195 | .ramp_delay = (dvba_reg) ? 800 : 0, \ | |
196 | .fixed_uV = (dvb_mask) ? 0 : 725000, \ | |
197 | .ops = <c3676_ ## _ops ## _regulator_ops, \ | |
198 | .type = REGULATOR_VOLTAGE, \ | |
199 | .id = LTC3676_ ## _id, \ | |
200 | .owner = THIS_MODULE, \ | |
201 | .vsel_reg = (dvba_reg), \ | |
202 | .vsel_mask = (dvb_mask), \ | |
203 | .enable_reg = (en_reg), \ | |
204 | .enable_mask = (1 << en_bit), \ | |
205 | } | |
206 | ||
207 | #define LTC3676_LINEAR_REG(_id, _name, _en, _dvba) \ | |
208 | LTC3676_REG(_id, _name, linear, \ | |
209 | LTC3676_ ## _en, 7, \ | |
210 | LTC3676_ ## _dvba, 0x1f) | |
211 | ||
212 | #define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit) \ | |
213 | LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0) | |
214 | ||
215 | static struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = { | |
216 | LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A), | |
217 | LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A), | |
218 | LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A), | |
219 | LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A), | |
220 | LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0), | |
221 | LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2), | |
222 | LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5), | |
223 | LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2), | |
224 | }; | |
225 | ||
226 | static bool ltc3676_writeable_reg(struct device *dev, unsigned int reg) | |
227 | { | |
228 | switch (reg) { | |
229 | case LTC3676_IRQSTAT: | |
230 | case LTC3676_BUCK1: | |
231 | case LTC3676_BUCK2: | |
232 | case LTC3676_BUCK3: | |
233 | case LTC3676_BUCK4: | |
234 | case LTC3676_LDOA: | |
235 | case LTC3676_LDOB: | |
236 | case LTC3676_SQD1: | |
237 | case LTC3676_SQD2: | |
238 | case LTC3676_CNTRL: | |
239 | case LTC3676_DVB1A: | |
240 | case LTC3676_DVB1B: | |
241 | case LTC3676_DVB2A: | |
242 | case LTC3676_DVB2B: | |
243 | case LTC3676_DVB3A: | |
244 | case LTC3676_DVB3B: | |
245 | case LTC3676_DVB4A: | |
246 | case LTC3676_DVB4B: | |
247 | case LTC3676_MSKIRQ: | |
248 | case LTC3676_MSKPG: | |
249 | case LTC3676_USER: | |
250 | case LTC3676_HRST: | |
251 | case LTC3676_CLIRQ: | |
252 | return true; | |
253 | } | |
254 | return false; | |
255 | } | |
256 | ||
257 | static bool ltc3676_readable_reg(struct device *dev, unsigned int reg) | |
258 | { | |
259 | switch (reg) { | |
260 | case LTC3676_IRQSTAT: | |
261 | case LTC3676_BUCK1: | |
262 | case LTC3676_BUCK2: | |
263 | case LTC3676_BUCK3: | |
264 | case LTC3676_BUCK4: | |
265 | case LTC3676_LDOA: | |
266 | case LTC3676_LDOB: | |
267 | case LTC3676_SQD1: | |
268 | case LTC3676_SQD2: | |
269 | case LTC3676_CNTRL: | |
270 | case LTC3676_DVB1A: | |
271 | case LTC3676_DVB1B: | |
272 | case LTC3676_DVB2A: | |
273 | case LTC3676_DVB2B: | |
274 | case LTC3676_DVB3A: | |
275 | case LTC3676_DVB3B: | |
276 | case LTC3676_DVB4A: | |
277 | case LTC3676_DVB4B: | |
278 | case LTC3676_MSKIRQ: | |
279 | case LTC3676_MSKPG: | |
280 | case LTC3676_USER: | |
281 | case LTC3676_HRST: | |
282 | case LTC3676_CLIRQ: | |
283 | return true; | |
284 | } | |
285 | return false; | |
286 | } | |
287 | ||
288 | static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg) | |
289 | { | |
290 | switch (reg) { | |
291 | case LTC3676_IRQSTAT: | |
292 | case LTC3676_PGSTATL: | |
293 | case LTC3676_PGSTATRT: | |
294 | return true; | |
295 | } | |
296 | return false; | |
297 | } | |
298 | ||
299 | static const struct regmap_config ltc3676_regmap_config = { | |
300 | .reg_bits = 8, | |
301 | .val_bits = 8, | |
302 | .writeable_reg = ltc3676_writeable_reg, | |
303 | .readable_reg = ltc3676_readable_reg, | |
304 | .volatile_reg = ltc3676_volatile_reg, | |
305 | .max_register = LTC3676_CLIRQ, | |
306 | .use_single_rw = true, | |
307 | .cache_type = REGCACHE_RBTREE, | |
308 | }; | |
309 | ||
310 | static irqreturn_t ltc3676_isr(int irq, void *dev_id) | |
311 | { | |
312 | struct ltc3676 *ltc3676 = dev_id; | |
313 | struct device *dev = ltc3676->dev; | |
314 | unsigned int i, irqstat, event; | |
315 | ||
316 | regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat); | |
317 | ||
318 | dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat); | |
319 | if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) { | |
320 | dev_warn(dev, "Over-temperature Warning\n"); | |
321 | event = REGULATOR_EVENT_OVER_TEMP; | |
322 | for (i = 0; i < LTC3676_NUM_REGULATORS; i++) | |
323 | regulator_notifier_call_chain(ltc3676->regulators[i], | |
324 | event, NULL); | |
325 | } | |
326 | ||
327 | if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) { | |
328 | dev_info(dev, "Undervoltage Warning\n"); | |
329 | event = REGULATOR_EVENT_UNDER_VOLTAGE; | |
330 | for (i = 0; i < LTC3676_NUM_REGULATORS; i++) | |
331 | regulator_notifier_call_chain(ltc3676->regulators[i], | |
332 | event, NULL); | |
333 | } | |
334 | ||
335 | /* Clear warning condition */ | |
336 | regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); | |
337 | ||
338 | return IRQ_HANDLED; | |
339 | } | |
340 | ||
341 | static int ltc3676_regulator_probe(struct i2c_client *client, | |
342 | const struct i2c_device_id *id) | |
343 | { | |
344 | struct device *dev = &client->dev; | |
345 | struct regulator_init_data *init_data = dev_get_platdata(dev); | |
346 | struct regulator_desc *descs; | |
347 | struct ltc3676 *ltc3676; | |
348 | int i, ret; | |
349 | ||
350 | ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL); | |
351 | if (!ltc3676) | |
352 | return -ENOMEM; | |
353 | ||
354 | i2c_set_clientdata(client, ltc3676); | |
355 | ltc3676->dev = dev; | |
356 | ||
357 | descs = ltc3676->regulator_descs; | |
358 | memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators)); | |
359 | descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */ | |
360 | ||
361 | ltc3676->regmap = devm_regmap_init_i2c(client, <c3676_regmap_config); | |
362 | if (IS_ERR(ltc3676->regmap)) { | |
363 | ret = PTR_ERR(ltc3676->regmap); | |
364 | dev_err(dev, "failed to initialize regmap: %d\n", ret); | |
365 | return ret; | |
366 | } | |
367 | ||
368 | for (i = 0; i < LTC3676_NUM_REGULATORS; i++) { | |
369 | struct regulator_desc *desc = <c3676->regulator_descs[i]; | |
370 | struct regulator_config config = { }; | |
371 | ||
372 | if (init_data) | |
373 | config.init_data = &init_data[i]; | |
374 | ||
375 | config.dev = dev; | |
376 | config.driver_data = ltc3676; | |
377 | ||
378 | ltc3676->regulators[i] = devm_regulator_register(dev, desc, | |
379 | &config); | |
380 | if (IS_ERR(ltc3676->regulators[i])) { | |
381 | ret = PTR_ERR(ltc3676->regulators[i]); | |
382 | dev_err(dev, "failed to register regulator %s: %d\n", | |
383 | desc->name, ret); | |
384 | return ret; | |
385 | } | |
386 | } | |
387 | ||
388 | regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); | |
389 | if (client->irq) { | |
390 | ret = devm_request_threaded_irq(dev, client->irq, NULL, | |
391 | ltc3676_isr, | |
392 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, | |
393 | client->name, ltc3676); | |
394 | if (ret) { | |
395 | dev_err(dev, "Failed to request IRQ: %d\n", ret); | |
396 | return ret; | |
397 | } | |
398 | } | |
399 | ||
400 | return 0; | |
401 | } | |
402 | ||
403 | static const struct i2c_device_id ltc3676_i2c_id[] = { | |
404 | { "ltc3676" }, | |
405 | { } | |
406 | }; | |
407 | MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id); | |
408 | ||
c3143415 JMC |
409 | static const struct of_device_id ltc3676_of_match[] = { |
410 | { .compatible = "lltc,ltc3676" }, | |
411 | { }, | |
412 | }; | |
413 | MODULE_DEVICE_TABLE(of, ltc3676_of_match); | |
414 | ||
37b918a0 TH |
415 | static struct i2c_driver ltc3676_driver = { |
416 | .driver = { | |
417 | .name = DRIVER_NAME, | |
c3143415 | 418 | .of_match_table = of_match_ptr(ltc3676_of_match), |
37b918a0 TH |
419 | }, |
420 | .probe = ltc3676_regulator_probe, | |
421 | .id_table = ltc3676_i2c_id, | |
422 | }; | |
423 | module_i2c_driver(ltc3676_driver); | |
424 | ||
425 | MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>"); | |
426 | MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC1376"); | |
427 | MODULE_LICENSE("GPL v2"); |