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 | |
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, min_uV: uV, max_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(map: ltc3676->regmap, reg: rdev->desc->vsel_reg + 1, |
87 | mask: rdev->desc->vsel_mask, val: sel); |
88 | } |
89 | |
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(map: ltc3676->regmap, reg: rdev->desc->vsel_reg, |
115 | mask, val); |
116 | } |
117 | |
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(map: ltc3676->regmap, reg: 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, sel: selector); |
133 | } |
134 | |
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 | |
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, propname: "lltc,fb-voltage-divider" , out_values: r, sz: 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(uV: desc->min_uV, r1: r[0], r2: r[1]); |
166 | rdesc->uV_step = ltc3676_scale(uV: desc->uV_step, r1: r[0], r2: r[1]); |
167 | rdesc->fixed_uV = ltc3676_scale(uV: desc->fixed_uV, r1: r[0], r2: 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 | |
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 | |
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_MAPLE, |
265 | }; |
266 | |
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(map: ltc3676->regmap, LTC3676_IRQSTAT, val: &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(rdev: 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(rdev: ltc3676->regulators[i], |
289 | event, NULL); |
290 | } |
291 | |
292 | /* Clear warning condition */ |
293 | regmap_write(map: ltc3676->regmap, LTC3676_CLIRQ, val: 0); |
294 | |
295 | return IRQ_HANDLED; |
296 | } |
297 | |
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, size: sizeof(*ltc3676), GFP_KERNEL); |
307 | if (!ltc3676) |
308 | return -ENOMEM; |
309 | |
310 | i2c_set_clientdata(client, data: 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(ptr: ltc3676->regmap)) { |
319 | ret = PTR_ERR(ptr: 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, regulator_desc: desc, |
335 | config: &config); |
336 | if (IS_ERR(ptr: ltc3676->regulators[i])) { |
337 | ret = PTR_ERR(ptr: 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(map: ltc3676->regmap, LTC3676_CLIRQ, val: 0); |
345 | if (client->irq) { |
346 | ret = devm_request_threaded_irq(dev, irq: client->irq, NULL, |
347 | thread_fn: ltc3676_isr, |
348 | IRQF_TRIGGER_LOW | IRQF_ONESHOT, |
349 | devname: client->name, dev_id: 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 | .probe_type = PROBE_PREFER_ASYNCHRONOUS, |
375 | .of_match_table = of_match_ptr(ltc3676_of_match), |
376 | }, |
377 | .probe = ltc3676_regulator_probe, |
378 | .id_table = ltc3676_i2c_id, |
379 | }; |
380 | module_i2c_driver(ltc3676_driver); |
381 | |
382 | MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>" ); |
383 | MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676" ); |
384 | MODULE_LICENSE("GPL v2" ); |
385 | |