1// SPDX-License-Identifier: GPL-2.0
2//
3// Copyright (c) 2019 five technologies GmbH
4// Author: Markus Reichl <m.reichl@fivetechno.de>
5
6#include <linux/module.h>
7#include <linux/i2c.h>
8#include <linux/of.h>
9#include <linux/regulator/driver.h>
10#include <linux/regmap.h>
11
12
13#define VOL_MIN_IDX			0x00
14#define VOL_MAX_IDX			0x7ff
15
16/* Register definitions */
17#define MP8859_VOUT_L_REG		0    //3 lo Bits
18#define MP8859_VOUT_H_REG		1    //8 hi Bits
19#define MP8859_VOUT_GO_REG		2
20#define MP8859_IOUT_LIM_REG		3
21#define MP8859_CTL1_REG			4
22#define MP8859_CTL2_REG			5
23#define MP8859_RESERVED1_REG		6
24#define MP8859_RESERVED2_REG		7
25#define MP8859_RESERVED3_REG		8
26#define MP8859_STATUS_REG		9
27#define MP8859_INTERRUPT_REG		0x0A
28#define MP8859_MASK_REG			0x0B
29#define MP8859_ID1_REG			0x0C
30#define MP8859_MFR_ID_REG		0x27
31#define MP8859_DEV_ID_REG		0x28
32#define MP8859_IC_REV_REG		0x29
33
34#define MP8859_MAX_REG			0x29
35
36#define MP8859_GO_BIT			0x01
37
38#define MP8859_IOUT_LIM_MASK		0x7f
39
40#define MP8859_ENABLE_MASK		0x80
41#define MP8859_DISCHG_EN_MASK		0x10
42#define MP8859_MODE_MASK		0x08
43
44#define MP8859_PG_MASK			0x80
45#define MP8859_OTP_MASK			0x40
46#define MP8859_OTW_MASK			0x20
47#define MP8859_CC_CV_MASK		0x10
48
49static int mp8859_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
50{
51	int ret;
52
53	ret = regmap_write(rdev->regmap, MP8859_VOUT_L_REG, sel & 0x7);
54
55	if (ret)
56		return ret;
57	ret = regmap_write(rdev->regmap, MP8859_VOUT_H_REG, sel >> 3);
58
59	if (ret)
60		return ret;
61	ret = regmap_update_bits(rdev->regmap, MP8859_VOUT_GO_REG,
62					MP8859_GO_BIT, 1);
63	return ret;
64}
65
66static int mp8859_get_voltage_sel(struct regulator_dev *rdev)
67{
68	unsigned int val_tmp;
69	unsigned int val;
70	int ret;
71
72	ret = regmap_read(rdev->regmap, MP8859_VOUT_H_REG, &val_tmp);
73
74	if (ret)
75		return ret;
76	val = val_tmp << 3;
77
78	ret = regmap_read(rdev->regmap, MP8859_VOUT_L_REG, &val_tmp);
79
80	if (ret)
81		return ret;
82	val |= val_tmp & 0x07;
83	return val;
84}
85
86static int mp8859_set_voltage_time_sel(struct regulator_dev *rdev,
87				       unsigned int from, unsigned int to)
88{
89	int change;
90
91	/* The voltage ramps at 1mV/uS, selectors are 10mV */
92	if (from > to)
93		change = from - to;
94	else
95		change = to - from;
96
97	return change * 10 * 1000;
98}
99
100static unsigned int mp8859_get_mode(struct regulator_dev *rdev)
101{
102	unsigned int val;
103	int ret;
104
105	ret = regmap_read(rdev->regmap, MP8859_CTL1_REG, &val);
106	if (ret != 0) {
107		dev_err(&rdev->dev, "Failed to read mode: %d\n", ret);
108		return 0;
109	}
110
111	if (val & MP8859_MODE_MASK)
112		return REGULATOR_MODE_FAST;
113	else
114		return REGULATOR_MODE_NORMAL;
115}
116
117static int mp8859_set_mode(struct regulator_dev *rdev, unsigned int mode)
118{
119	unsigned int val;
120
121	switch (mode) {
122	case REGULATOR_MODE_FAST:
123		val = MP8859_MODE_MASK;
124		break;
125	case REGULATOR_MODE_NORMAL:
126		val = 0;
127		break;
128	default:
129		return -EINVAL;
130	}
131
132	return regmap_update_bits(rdev->regmap, MP8859_CTL1_REG,
133				  MP8859_MODE_MASK, val);
134}
135
136static int mp8859_set_current_limit(struct regulator_dev *rdev,
137				    int min_uA, int max_uA)
138{
139	unsigned int cur_val, new_val;
140	int ret, i;
141
142	/* Steps of 50mA */
143	new_val = max_uA / 50000;
144	if (new_val > MP8859_IOUT_LIM_MASK)
145		return -EINVAL;
146	if (new_val == 0)
147		return -EINVAL;
148
149	/*
150	 * If the regulator is limiting then ramp gradually as per
151	 * datasheet, otherwise just set the value directly.
152	 */
153	ret = regmap_read(rdev->regmap, MP8859_STATUS_REG, &cur_val);
154	if (ret != 0)
155		return ret;
156	if (!(cur_val & MP8859_CC_CV_MASK)) {
157		return regmap_update_bits(rdev->regmap, MP8859_IOUT_LIM_REG,
158					  MP8859_IOUT_LIM_MASK, new_val);
159	}
160
161	ret = regmap_read(rdev->regmap, MP8859_IOUT_LIM_REG, &cur_val);
162	if (ret != 0)
163		return ret;
164
165	if (cur_val >= new_val) {
166		for (i = cur_val; i >= new_val; i--) {
167			ret = regmap_update_bits(rdev->regmap,
168						 MP8859_IOUT_LIM_REG,
169						 MP8859_IOUT_LIM_MASK,
170						 cur_val - i);
171			if (ret != 0)
172				return ret;
173		}
174	} else {
175		for (i = cur_val; i <= new_val; i++) {
176			ret = regmap_update_bits(rdev->regmap,
177						 MP8859_IOUT_LIM_REG,
178						 MP8859_IOUT_LIM_MASK,
179						 cur_val + i);
180			if (ret != 0)
181				return ret;
182		}
183	}
184
185	return 0;
186}
187
188static int mp8859_get_status(struct regulator_dev *rdev)
189{
190	unsigned int val;
191	int ret;
192
193	/* Output status is only meaingful when enabled */
194	ret = regmap_read(rdev->regmap, MP8859_CTL1_REG, &val);
195	if (ret != 0)
196		return ret;
197	if (!(val & MP8859_ENABLE_MASK))
198		return REGULATOR_STATUS_UNDEFINED;
199
200	ret = regmap_read(rdev->regmap, MP8859_STATUS_REG, &val);
201	if (ret != 0)
202		return ret;
203
204	if (val & MP8859_PG_MASK)
205		return REGULATOR_STATUS_ON;
206	else
207		return REGULATOR_STATUS_ERROR;
208}
209
210static int mp8859_get_error_flags(struct regulator_dev *rdev,
211				  unsigned int *flags)
212{
213	unsigned int status, enabled;
214	int ret;
215
216	*flags = 0;
217
218	/* Output status is only meaingful when enabled */
219	ret = regmap_read(rdev->regmap, MP8859_CTL1_REG, &enabled);
220	if (ret != 0)
221		return ret;
222	enabled &= MP8859_ENABLE_MASK;
223
224	ret = regmap_read(rdev->regmap, MP8859_STATUS_REG, &status);
225	if (ret != 0)
226		return ret;
227
228	if (enabled && !(status & MP8859_PG_MASK))
229		status |= REGULATOR_ERROR_FAIL;
230	if (status & MP8859_OTP_MASK)
231		status |= REGULATOR_ERROR_OVER_TEMP;
232	if (status & MP8859_OTW_MASK)
233		status |= REGULATOR_ERROR_OVER_TEMP_WARN;
234	if (status & MP8859_CC_CV_MASK)
235		status |= REGULATOR_ERROR_OVER_CURRENT;
236
237	return 0;
238}
239
240static const struct linear_range mp8859_dcdc_ranges[] = {
241	REGULATOR_LINEAR_RANGE(0, VOL_MIN_IDX, VOL_MAX_IDX, 10000),
242};
243
244static bool mp8859_readable(struct device *dev, unsigned int reg)
245{
246	switch (reg) {
247	case MP8859_VOUT_L_REG:
248	case MP8859_VOUT_H_REG:
249	case MP8859_VOUT_GO_REG:
250	case MP8859_IOUT_LIM_REG:
251	case MP8859_CTL1_REG:
252	case MP8859_CTL2_REG:
253	case MP8859_STATUS_REG:
254	case MP8859_INTERRUPT_REG:
255	case MP8859_MASK_REG:
256	case MP8859_ID1_REG:
257	case MP8859_MFR_ID_REG:
258	case MP8859_DEV_ID_REG:
259	case MP8859_IC_REV_REG:
260		return true;
261	default:
262		return false;
263	}
264}
265
266static bool mp8859_volatile(struct device *dev, unsigned int reg)
267{
268	switch (reg) {
269	case MP8859_VOUT_GO_REG:
270	case MP8859_STATUS_REG:
271	case MP8859_INTERRUPT_REG:
272		return true;
273	default:
274		return false;
275	}
276}
277
278static const struct regmap_config mp8859_regmap = {
279	.reg_bits = 8,
280	.val_bits = 8,
281	.max_register = MP8859_MAX_REG,
282	.cache_type = REGCACHE_MAPLE,
283	.readable_reg = mp8859_readable,
284	.volatile_reg = mp8859_volatile,
285};
286
287static const struct regulator_ops mp8859_ops = {
288	.set_voltage_sel = mp8859_set_voltage_sel,
289	.get_voltage_sel = mp8859_get_voltage_sel,
290	.list_voltage = regulator_list_voltage_linear_range,
291	.set_voltage_time_sel = mp8859_set_voltage_time_sel,
292	.enable = regulator_enable_regmap,
293	.disable = regulator_disable_regmap,
294	.is_enabled = regulator_is_enabled_regmap,
295	.set_mode = mp8859_set_mode,
296	.get_mode = mp8859_get_mode,
297	.set_active_discharge = regulator_set_active_discharge_regmap,
298	.set_current_limit = mp8859_set_current_limit,
299	.get_status = mp8859_get_status,
300	.get_error_flags = mp8859_get_error_flags,
301};
302
303static const struct regulator_desc mp8859_regulators[] = {
304	{
305		.id = 0,
306		.type = REGULATOR_VOLTAGE,
307		.name = "mp8859_dcdc",
308		.supply_name = "vin",
309		.of_match = of_match_ptr("mp8859_dcdc"),
310		.n_voltages = VOL_MAX_IDX + 1,
311		.linear_ranges = mp8859_dcdc_ranges,
312		.n_linear_ranges = 1,
313		.enable_reg = MP8859_CTL1_REG,
314		.enable_mask = MP8859_ENABLE_MASK,
315		.enable_val = MP8859_ENABLE_MASK,
316		.active_discharge_reg = MP8859_CTL1_REG,
317		.active_discharge_on = MP8859_DISCHG_EN_MASK,
318		.active_discharge_mask = MP8859_DISCHG_EN_MASK,
319		.ops = &mp8859_ops,
320		.owner = THIS_MODULE,
321	},
322};
323
324static int mp8859_i2c_probe(struct i2c_client *i2c)
325{
326	int ret;
327	struct regulator_config config = {.dev = &i2c->dev};
328	struct regmap *regmap = devm_regmap_init_i2c(i2c, &mp8859_regmap);
329	struct regulator_dev *rdev;
330	unsigned int val, rev;
331
332	if (IS_ERR(regmap)) {
333		ret = PTR_ERR(regmap);
334		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
335		return ret;
336	}
337
338	ret = regmap_read(regmap, MP8859_MFR_ID_REG, &val);
339	if (ret != 0) {
340		dev_err(&i2c->dev, "Failed to read manufacturer ID: %d\n", ret);
341		return ret;
342	}
343	if (val != 0x9) {
344		dev_err(&i2c->dev, "Manufacturer ID %x != 9\n", val);
345		return -EINVAL;
346	}
347
348	ret = regmap_read(regmap, MP8859_DEV_ID_REG, &val);
349	if (ret != 0) {
350		dev_err(&i2c->dev, "Failed to read device ID: %d\n", ret);
351		return ret;
352	}
353	if (val != 0x58) {
354		dev_err(&i2c->dev, "Manufacturer ID %x != 0x58\n", val);
355		return -EINVAL;
356	}
357
358	ret = regmap_read(regmap, MP8859_IC_REV_REG, &rev);
359	if (ret != 0) {
360		dev_err(&i2c->dev, "Failed to read device revision: %d\n", ret);
361		return ret;
362	}
363	ret = regmap_read(regmap, MP8859_ID1_REG, &val);
364	if (ret != 0) {
365		dev_err(&i2c->dev, "Failed to read device ID1: %d\n", ret);
366		return ret;
367	}
368	dev_info(&i2c->dev, "MP8859-%04d revision %d\n", val, rev);
369
370	rdev = devm_regulator_register(&i2c->dev, &mp8859_regulators[0],
371					&config);
372
373	if (IS_ERR(rdev)) {
374		ret = PTR_ERR(rdev);
375		dev_err(&i2c->dev, "failed to register %s: %d\n",
376			mp8859_regulators[0].name, ret);
377		return ret;
378	}
379	return 0;
380}
381
382static const struct of_device_id mp8859_dt_id[] __maybe_unused = {
383	{.compatible =  "mps,mp8859"},
384	{},
385};
386MODULE_DEVICE_TABLE(of, mp8859_dt_id);
387
388static const struct i2c_device_id mp8859_i2c_id[] = {
389	{ "mp8859", },
390	{  },
391};
392MODULE_DEVICE_TABLE(i2c, mp8859_i2c_id);
393
394static struct i2c_driver mp8859_regulator_driver = {
395	.driver = {
396		.name = "mp8859",
397		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
398		.of_match_table = of_match_ptr(mp8859_dt_id),
399	},
400	.probe = mp8859_i2c_probe,
401	.id_table = mp8859_i2c_id,
402};
403
404module_i2c_driver(mp8859_regulator_driver);
405
406MODULE_DESCRIPTION("Monolithic Power Systems MP8859 voltage regulator driver");
407MODULE_AUTHOR("Markus Reichl <m.reichl@fivetechno.de>");
408MODULE_LICENSE("GPL v2");
409