Merge branch 'for-4.15/asus' into for-linus
[sfrench/cifs-2.6.git] / drivers / regulator / ltc3676.c
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 = &ltc3676->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 */
164 static const struct regulator_ops ltc3676_linear_regulator_ops = {
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 */
176 static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
177 };
178
179 /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
180 static const struct regulator_ops ltc3676_fixed_regulator_ops = {
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 = &ltc3676_ ## _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, &ltc3676_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 = &ltc3676->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
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
415 static struct i2c_driver ltc3676_driver = {
416         .driver = {
417                 .name = DRIVER_NAME,
418                 .of_match_table = of_match_ptr(ltc3676_of_match),
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");