1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved.
4 */
5 #include <linux/i2c.h>
6 #include <linux/init.h>
7 #include <linux/interrupt.h>
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/of.h>
11 #include <linux/regmap.h>
12 #include <linux/regulator/driver.h>
13 #include <linux/regulator/machine.h>
14 #include <linux/regulator/of_regulator.h>
15
16 #define DRIVER_NAME "ltc3676"
17
18 /* LTC3676 Registers */
19 #define LTC3676_BUCK1 0x01
20 #define LTC3676_BUCK2 0x02
21 #define LTC3676_BUCK3 0x03
22 #define LTC3676_BUCK4 0x04
23 #define LTC3676_LDOA 0x05
24 #define LTC3676_LDOB 0x06
25 #define LTC3676_SQD1 0x07
26 #define LTC3676_SQD2 0x08
27 #define LTC3676_CNTRL 0x09
28 #define LTC3676_DVB1A 0x0A
29 #define LTC3676_DVB1B 0x0B
30 #define LTC3676_DVB2A 0x0C
31 #define LTC3676_DVB2B 0x0D
32 #define LTC3676_DVB3A 0x0E
33 #define LTC3676_DVB3B 0x0F
34 #define LTC3676_DVB4A 0x10
35 #define LTC3676_DVB4B 0x11
36 #define LTC3676_MSKIRQ 0x12
37 #define LTC3676_MSKPG 0x13
38 #define LTC3676_USER 0x14
39 #define LTC3676_IRQSTAT 0x15
40 #define LTC3676_PGSTATL 0x16
41 #define LTC3676_PGSTATRT 0x17
42 #define LTC3676_HRST 0x1E
43 #define LTC3676_CLIRQ 0x1F
44
45 #define LTC3676_DVBxA_REF_SELECT BIT(5)
46 #define LTC3676_DVBxB_PGOOD_MASK BIT(5)
47
48 #define LTC3676_IRQSTAT_PGOOD_TIMEOUT BIT(3)
49 #define LTC3676_IRQSTAT_UNDERVOLT_WARN BIT(4)
50 #define LTC3676_IRQSTAT_UNDERVOLT_FAULT BIT(5)
51 #define LTC3676_IRQSTAT_THERMAL_WARN BIT(6)
52 #define LTC3676_IRQSTAT_THERMAL_FAULT BIT(7)
53
54 enum ltc3676_reg {
55 LTC3676_SW1,
56 LTC3676_SW2,
57 LTC3676_SW3,
58 LTC3676_SW4,
59 LTC3676_LDO1,
60 LTC3676_LDO2,
61 LTC3676_LDO3,
62 LTC3676_LDO4,
63 LTC3676_NUM_REGULATORS,
64 };
65
66 struct ltc3676 {
67 struct regmap *regmap;
68 struct device *dev;
69 struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS];
70 struct regulator_dev *regulators[LTC3676_NUM_REGULATORS];
71 };
72
ltc3676_set_suspend_voltage(struct regulator_dev * rdev,int uV)73 static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV)
74 {
75 struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
76 struct device *dev = ltc3676->dev;
77 int dcdc = rdev_get_id(rdev);
78 int sel;
79
80 dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV);
81 sel = regulator_map_voltage_linear(rdev, uV, uV);
82 if (sel < 0)
83 return sel;
84
85 /* DVBB register follows right after the corresponding DVBA register */
86 return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
87 rdev->desc->vsel_mask, sel);
88 }
89
ltc3676_set_suspend_mode(struct regulator_dev * rdev,unsigned int mode)90 static int ltc3676_set_suspend_mode(struct regulator_dev *rdev,
91 unsigned int mode)
92 {
93 struct ltc3676 *ltc3676= rdev_get_drvdata(rdev);
94 struct device *dev = ltc3676->dev;
95 int mask, val;
96 int dcdc = rdev_get_id(rdev);
97
98 dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode);
99
100 mask = LTC3676_DVBxA_REF_SELECT;
101 switch (mode) {
102 case REGULATOR_MODE_STANDBY:
103 val = 0; /* select DVBxA */
104 break;
105 case REGULATOR_MODE_NORMAL:
106 val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */
107 break;
108 default:
109 dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n",
110 rdev->desc->name, mode);
111 return -EINVAL;
112 }
113
114 return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg,
115 mask, val);
116 }
117
ltc3676_set_voltage_sel(struct regulator_dev * rdev,unsigned selector)118 static int ltc3676_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
119 {
120 struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
121 struct device *dev = ltc3676->dev;
122 int ret, dcdc = rdev_get_id(rdev);
123
124 dev_dbg(dev, "%s id=%d selector=%d\n", __func__, dcdc, selector);
125
126 ret = regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
127 LTC3676_DVBxB_PGOOD_MASK,
128 LTC3676_DVBxB_PGOOD_MASK);
129 if (ret)
130 return ret;
131
132 return regulator_set_voltage_sel_regmap(rdev, selector);
133 }
134
ltc3676_scale(unsigned int uV,u32 r1,u32 r2)135 static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2)
136 {
137 uint64_t tmp;
138 if (uV == 0)
139 return 0;
140 tmp = (uint64_t)uV * r1;
141 do_div(tmp, r2);
142 return uV + (unsigned int)tmp;
143 }
144
ltc3676_of_parse_cb(struct device_node * np,const struct regulator_desc * desc,struct regulator_config * config)145 static int ltc3676_of_parse_cb(struct device_node *np,
146 const struct regulator_desc *desc,
147 struct regulator_config *config)
148 {
149 struct ltc3676 *ltc3676 = config->driver_data;
150 struct regulator_desc *rdesc = <c3676->regulator_descs[desc->id];
151 u32 r[2];
152 int ret;
153
154 /* LDO3 has a fixed output */
155 if (desc->id == LTC3676_LDO3)
156 return 0;
157
158 ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
159 if (ret) {
160 dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n",
161 ret);
162 return ret;
163 }
164
165 rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]);
166 rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]);
167 rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]);
168
169 return 0;
170 }
171
172 /* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */
173 static const struct regulator_ops ltc3676_linear_regulator_ops = {
174 .enable = regulator_enable_regmap,
175 .disable = regulator_disable_regmap,
176 .is_enabled = regulator_is_enabled_regmap,
177 .list_voltage = regulator_list_voltage_linear,
178 .set_voltage_sel = ltc3676_set_voltage_sel,
179 .get_voltage_sel = regulator_get_voltage_sel_regmap,
180 .set_suspend_voltage = ltc3676_set_suspend_voltage,
181 .set_suspend_mode = ltc3676_set_suspend_mode,
182 };
183
184 /* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */
185 static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
186 };
187
188 /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
189 static const struct regulator_ops ltc3676_fixed_regulator_ops = {
190 .enable = regulator_enable_regmap,
191 .disable = regulator_disable_regmap,
192 .is_enabled = regulator_is_enabled_regmap,
193 };
194
195 #define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask) \
196 [LTC3676_ ## _id] = { \
197 .name = #_name, \
198 .of_match = of_match_ptr(#_name), \
199 .regulators_node = of_match_ptr("regulators"), \
200 .of_parse_cb = ltc3676_of_parse_cb, \
201 .n_voltages = (dvb_mask) + 1, \
202 .min_uV = (dvba_reg) ? 412500 : 0, \
203 .uV_step = (dvba_reg) ? 12500 : 0, \
204 .ramp_delay = (dvba_reg) ? 800 : 0, \
205 .fixed_uV = (dvb_mask) ? 0 : 725000, \
206 .ops = <c3676_ ## _ops ## _regulator_ops, \
207 .type = REGULATOR_VOLTAGE, \
208 .id = LTC3676_ ## _id, \
209 .owner = THIS_MODULE, \
210 .vsel_reg = (dvba_reg), \
211 .vsel_mask = (dvb_mask), \
212 .enable_reg = (en_reg), \
213 .enable_mask = (1 << en_bit), \
214 }
215
216 #define LTC3676_LINEAR_REG(_id, _name, _en, _dvba) \
217 LTC3676_REG(_id, _name, linear, \
218 LTC3676_ ## _en, 7, \
219 LTC3676_ ## _dvba, 0x1f)
220
221 #define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit) \
222 LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0)
223
224 static const struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = {
225 LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A),
226 LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A),
227 LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A),
228 LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A),
229 LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0),
230 LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2),
231 LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5),
232 LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2),
233 };
234
ltc3676_readable_writeable_reg(struct device * dev,unsigned int reg)235 static bool ltc3676_readable_writeable_reg(struct device *dev, unsigned int reg)
236 {
237 switch (reg) {
238 case LTC3676_BUCK1 ... LTC3676_IRQSTAT:
239 case LTC3676_HRST:
240 case LTC3676_CLIRQ:
241 return true;
242 }
243 return false;
244 }
245
ltc3676_volatile_reg(struct device * dev,unsigned int reg)246 static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg)
247 {
248 switch (reg) {
249 case LTC3676_IRQSTAT ... LTC3676_PGSTATRT:
250 return true;
251 }
252 return false;
253 }
254
255 static const struct regmap_config ltc3676_regmap_config = {
256 .reg_bits = 8,
257 .val_bits = 8,
258 .writeable_reg = ltc3676_readable_writeable_reg,
259 .readable_reg = ltc3676_readable_writeable_reg,
260 .volatile_reg = ltc3676_volatile_reg,
261 .max_register = LTC3676_CLIRQ,
262 .use_single_read = true,
263 .use_single_write = true,
264 .cache_type = REGCACHE_RBTREE,
265 };
266
ltc3676_isr(int irq,void * dev_id)267 static irqreturn_t ltc3676_isr(int irq, void *dev_id)
268 {
269 struct ltc3676 *ltc3676 = dev_id;
270 struct device *dev = ltc3676->dev;
271 unsigned int i, irqstat, event;
272
273 regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat);
274
275 dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat);
276 if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) {
277 dev_warn(dev, "Over-temperature Warning\n");
278 event = REGULATOR_EVENT_OVER_TEMP;
279 for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
280 regulator_notifier_call_chain(ltc3676->regulators[i],
281 event, NULL);
282 }
283
284 if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
285 dev_info(dev, "Undervoltage Warning\n");
286 event = REGULATOR_EVENT_UNDER_VOLTAGE;
287 for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
288 regulator_notifier_call_chain(ltc3676->regulators[i],
289 event, NULL);
290 }
291
292 /* Clear warning condition */
293 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
294
295 return IRQ_HANDLED;
296 }
297
ltc3676_regulator_probe(struct i2c_client * client)298 static int ltc3676_regulator_probe(struct i2c_client *client)
299 {
300 struct device *dev = &client->dev;
301 struct regulator_init_data *init_data = dev_get_platdata(dev);
302 struct regulator_desc *descs;
303 struct ltc3676 *ltc3676;
304 int i, ret;
305
306 ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL);
307 if (!ltc3676)
308 return -ENOMEM;
309
310 i2c_set_clientdata(client, ltc3676);
311 ltc3676->dev = dev;
312
313 descs = ltc3676->regulator_descs;
314 memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators));
315 descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */
316
317 ltc3676->regmap = devm_regmap_init_i2c(client, <c3676_regmap_config);
318 if (IS_ERR(ltc3676->regmap)) {
319 ret = PTR_ERR(ltc3676->regmap);
320 dev_err(dev, "failed to initialize regmap: %d\n", ret);
321 return ret;
322 }
323
324 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
325 struct regulator_desc *desc = <c3676->regulator_descs[i];
326 struct regulator_config config = { };
327
328 if (init_data)
329 config.init_data = &init_data[i];
330
331 config.dev = dev;
332 config.driver_data = ltc3676;
333
334 ltc3676->regulators[i] = devm_regulator_register(dev, desc,
335 &config);
336 if (IS_ERR(ltc3676->regulators[i])) {
337 ret = PTR_ERR(ltc3676->regulators[i]);
338 dev_err(dev, "failed to register regulator %s: %d\n",
339 desc->name, ret);
340 return ret;
341 }
342 }
343
344 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
345 if (client->irq) {
346 ret = devm_request_threaded_irq(dev, client->irq, NULL,
347 ltc3676_isr,
348 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
349 client->name, ltc3676);
350 if (ret) {
351 dev_err(dev, "Failed to request IRQ: %d\n", ret);
352 return ret;
353 }
354 }
355
356 return 0;
357 }
358
359 static const struct i2c_device_id ltc3676_i2c_id[] = {
360 { "ltc3676" },
361 { }
362 };
363 MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);
364
365 static const struct of_device_id __maybe_unused ltc3676_of_match[] = {
366 { .compatible = "lltc,ltc3676" },
367 { },
368 };
369 MODULE_DEVICE_TABLE(of, ltc3676_of_match);
370
371 static struct i2c_driver ltc3676_driver = {
372 .driver = {
373 .name = DRIVER_NAME,
374 .of_match_table = of_match_ptr(ltc3676_of_match),
375 },
376 .probe_new = ltc3676_regulator_probe,
377 .id_table = ltc3676_i2c_id,
378 };
379 module_i2c_driver(ltc3676_driver);
380
381 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
382 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");
383 MODULE_LICENSE("GPL v2");
384