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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
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
62enum 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
74struct 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
81static 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
94 return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
95 rdev->desc->vsel_mask, sel);
96}
97
98static 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;
112 break;
113 case REGULATOR_MODE_NORMAL:
114 val = LTC3676_DVBxA_REF_SELECT;
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
126static 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
136static 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
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
164static 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
176static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
177};
178
179
180static 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 = <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
215static 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
226static 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
257static 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
288static 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
299static 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
310static 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
336 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
337
338 return IRQ_HANDLED;
339}
340
341static 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;
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
403static const struct i2c_device_id ltc3676_i2c_id[] = {
404 { "ltc3676" },
405 { }
406};
407MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);
408
409static const struct of_device_id ltc3676_of_match[] = {
410 { .compatible = "lltc,ltc3676" },
411 { },
412};
413MODULE_DEVICE_TABLE(of, ltc3676_of_match);
414
415static 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};
423module_i2c_driver(ltc3676_driver);
424
425MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
426MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC1376");
427MODULE_LICENSE("GPL v2");
428
