1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // MP8867/MP8869 regulator driver
4 //
5 // Copyright (C) 2020 Synaptics Incorporated
6 //
7 // Author: Jisheng Zhang <jszhang@kernel.org>
8 
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/module.h>
12 #include <linux/of_device.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/driver.h>
15 #include <linux/regulator/of_regulator.h>
16 
17 #define MP886X_VSEL		0x00
18 #define  MP886X_V_BOOT		(1 << 7)
19 #define MP886X_SYSCNTLREG1	0x01
20 #define  MP886X_MODE		(1 << 0)
21 #define  MP886X_SLEW_SHIFT	3
22 #define  MP886X_SLEW_MASK	(0x7 << MP886X_SLEW_SHIFT)
23 #define  MP886X_GO		(1 << 6)
24 #define  MP886X_EN		(1 << 7)
25 #define MP8869_SYSCNTLREG2	0x02
26 
27 struct mp886x_cfg_info {
28 	const struct regulator_ops *rops;
29 	const unsigned int slew_rates[8];
30 	const int switch_freq[4];
31 	const u8 fs_reg;
32 	const u8 fs_shift;
33 };
34 
35 struct mp886x_device_info {
36 	struct device *dev;
37 	struct regulator_desc desc;
38 	struct regulator_init_data *regulator;
39 	struct gpio_desc *en_gpio;
40 	const struct mp886x_cfg_info *ci;
41 	u32 r[2];
42 	unsigned int sel;
43 };
44 
mp886x_set_switch_freq(struct mp886x_device_info * di,struct regmap * regmap,u32 freq)45 static void mp886x_set_switch_freq(struct mp886x_device_info *di,
46 				   struct regmap *regmap,
47 				   u32 freq)
48 {
49 	const struct mp886x_cfg_info *ci = di->ci;
50 	int i;
51 
52 	for (i = 0; i < ARRAY_SIZE(ci->switch_freq); i++) {
53 		if (freq == ci->switch_freq[i]) {
54 			regmap_update_bits(regmap, ci->fs_reg,
55 				  0x3 << ci->fs_shift, i << ci->fs_shift);
56 			return;
57 		}
58 	}
59 
60 	dev_err(di->dev, "invalid frequency %d\n", freq);
61 }
62 
mp886x_set_mode(struct regulator_dev * rdev,unsigned int mode)63 static int mp886x_set_mode(struct regulator_dev *rdev, unsigned int mode)
64 {
65 	switch (mode) {
66 	case REGULATOR_MODE_FAST:
67 		regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
68 				   MP886X_MODE, MP886X_MODE);
69 		break;
70 	case REGULATOR_MODE_NORMAL:
71 		regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
72 				   MP886X_MODE, 0);
73 		break;
74 	default:
75 		return -EINVAL;
76 	}
77 	return 0;
78 }
79 
mp886x_get_mode(struct regulator_dev * rdev)80 static unsigned int mp886x_get_mode(struct regulator_dev *rdev)
81 {
82 	u32 val;
83 	int ret;
84 
85 	ret = regmap_read(rdev->regmap, MP886X_SYSCNTLREG1, &val);
86 	if (ret < 0)
87 		return ret;
88 	if (val & MP886X_MODE)
89 		return REGULATOR_MODE_FAST;
90 	else
91 		return REGULATOR_MODE_NORMAL;
92 }
93 
mp8869_set_voltage_sel(struct regulator_dev * rdev,unsigned int sel)94 static int mp8869_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
95 {
96 	int ret;
97 
98 	ret = regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
99 				 MP886X_GO, MP886X_GO);
100 	if (ret < 0)
101 		return ret;
102 
103 	sel <<= ffs(rdev->desc->vsel_mask) - 1;
104 	return regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
105 				  MP886X_V_BOOT | rdev->desc->vsel_mask, sel);
106 }
107 
mp8869_scale(unsigned int uv,u32 r1,u32 r2)108 static inline unsigned int mp8869_scale(unsigned int uv, u32 r1, u32 r2)
109 {
110 	u32 tmp = uv * r1 / r2;
111 
112 	return uv + tmp;
113 }
114 
mp8869_get_voltage_sel(struct regulator_dev * rdev)115 static int mp8869_get_voltage_sel(struct regulator_dev *rdev)
116 {
117 	struct mp886x_device_info *di = rdev_get_drvdata(rdev);
118 	int ret, uv;
119 	unsigned int val;
120 	bool fbloop;
121 
122 	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
123 	if (ret)
124 		return ret;
125 
126 	fbloop = val & MP886X_V_BOOT;
127 	if (fbloop) {
128 		uv = rdev->desc->min_uV;
129 		uv = mp8869_scale(uv, di->r[0], di->r[1]);
130 		return regulator_map_voltage_linear(rdev, uv, uv);
131 	}
132 
133 	val &= rdev->desc->vsel_mask;
134 	val >>= ffs(rdev->desc->vsel_mask) - 1;
135 
136 	return val;
137 }
138 
139 static const struct regulator_ops mp8869_regulator_ops = {
140 	.set_voltage_sel = mp8869_set_voltage_sel,
141 	.get_voltage_sel = mp8869_get_voltage_sel,
142 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
143 	.map_voltage = regulator_map_voltage_linear,
144 	.list_voltage = regulator_list_voltage_linear,
145 	.enable = regulator_enable_regmap,
146 	.disable = regulator_disable_regmap,
147 	.is_enabled = regulator_is_enabled_regmap,
148 	.set_mode = mp886x_set_mode,
149 	.get_mode = mp886x_get_mode,
150 	.set_ramp_delay = regulator_set_ramp_delay_regmap,
151 };
152 
153 static const struct mp886x_cfg_info mp8869_ci = {
154 	.rops = &mp8869_regulator_ops,
155 	.slew_rates = {
156 		40000,
157 		30000,
158 		20000,
159 		10000,
160 		5000,
161 		2500,
162 		1250,
163 		625,
164 	},
165 	.switch_freq = {
166 		500000,
167 		750000,
168 		1000000,
169 		1250000,
170 	},
171 	.fs_reg = MP8869_SYSCNTLREG2,
172 	.fs_shift = 4,
173 };
174 
mp8867_set_voltage_sel(struct regulator_dev * rdev,unsigned int sel)175 static int mp8867_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
176 {
177 	struct mp886x_device_info *di = rdev_get_drvdata(rdev);
178 	int ret, delta;
179 
180 	ret = mp8869_set_voltage_sel(rdev, sel);
181 	if (ret < 0)
182 		return ret;
183 
184 	delta = di->sel - sel;
185 	if (abs(delta) <= 5)
186 		ret = regmap_update_bits(rdev->regmap, MP886X_SYSCNTLREG1,
187 					 MP886X_GO, 0);
188 	di->sel = sel;
189 
190 	return ret;
191 }
192 
mp8867_get_voltage_sel(struct regulator_dev * rdev)193 static int mp8867_get_voltage_sel(struct regulator_dev *rdev)
194 {
195 	struct mp886x_device_info *di = rdev_get_drvdata(rdev);
196 	int ret, uv;
197 	unsigned int val;
198 	bool fbloop;
199 
200 	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
201 	if (ret)
202 		return ret;
203 
204 	fbloop = val & MP886X_V_BOOT;
205 
206 	val &= rdev->desc->vsel_mask;
207 	val >>= ffs(rdev->desc->vsel_mask) - 1;
208 
209 	if (fbloop) {
210 		uv = regulator_list_voltage_linear(rdev, val);
211 		uv = mp8869_scale(uv, di->r[0], di->r[1]);
212 		return regulator_map_voltage_linear(rdev, uv, uv);
213 	}
214 
215 	return val;
216 }
217 
218 static const struct regulator_ops mp8867_regulator_ops = {
219 	.set_voltage_sel = mp8867_set_voltage_sel,
220 	.get_voltage_sel = mp8867_get_voltage_sel,
221 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
222 	.map_voltage = regulator_map_voltage_linear,
223 	.list_voltage = regulator_list_voltage_linear,
224 	.enable = regulator_enable_regmap,
225 	.disable = regulator_disable_regmap,
226 	.is_enabled = regulator_is_enabled_regmap,
227 	.set_mode = mp886x_set_mode,
228 	.get_mode = mp886x_get_mode,
229 	.set_ramp_delay = regulator_set_ramp_delay_regmap,
230 };
231 
232 static const struct mp886x_cfg_info mp8867_ci = {
233 	.rops = &mp8867_regulator_ops,
234 	.slew_rates = {
235 		64000,
236 		32000,
237 		16000,
238 		8000,
239 		4000,
240 		2000,
241 		1000,
242 		500,
243 	},
244 	.switch_freq = {
245 		500000,
246 		750000,
247 		1000000,
248 		1500000,
249 	},
250 	.fs_reg = MP886X_SYSCNTLREG1,
251 	.fs_shift = 1,
252 };
253 
mp886x_regulator_register(struct mp886x_device_info * di,struct regulator_config * config)254 static int mp886x_regulator_register(struct mp886x_device_info *di,
255 				     struct regulator_config *config)
256 {
257 	struct regulator_desc *rdesc = &di->desc;
258 	struct regulator_dev *rdev;
259 
260 	rdesc->name = "mp886x-reg";
261 	rdesc->supply_name = "vin";
262 	rdesc->ops = di->ci->rops;
263 	rdesc->type = REGULATOR_VOLTAGE;
264 	rdesc->n_voltages = 128;
265 	rdesc->enable_reg = MP886X_SYSCNTLREG1;
266 	rdesc->enable_mask = MP886X_EN;
267 	rdesc->min_uV = 600000;
268 	rdesc->uV_step = 10000;
269 	rdesc->vsel_reg = MP886X_VSEL;
270 	rdesc->vsel_mask = 0x3f;
271 	rdesc->ramp_reg = MP886X_SYSCNTLREG1;
272 	rdesc->ramp_mask = MP886X_SLEW_MASK;
273 	rdesc->ramp_delay_table = di->ci->slew_rates;
274 	rdesc->n_ramp_values = ARRAY_SIZE(di->ci->slew_rates);
275 	rdesc->owner = THIS_MODULE;
276 
277 	rdev = devm_regulator_register(di->dev, &di->desc, config);
278 	if (IS_ERR(rdev))
279 		return PTR_ERR(rdev);
280 	di->sel = rdesc->ops->get_voltage_sel(rdev);
281 	return 0;
282 }
283 
284 static const struct regmap_config mp886x_regmap_config = {
285 	.reg_bits = 8,
286 	.val_bits = 8,
287 };
288 
mp886x_i2c_probe(struct i2c_client * client)289 static int mp886x_i2c_probe(struct i2c_client *client)
290 {
291 	struct device *dev = &client->dev;
292 	struct device_node *np = dev->of_node;
293 	struct mp886x_device_info *di;
294 	struct regulator_config config = { };
295 	struct regmap *regmap;
296 	u32 freq;
297 	int ret;
298 
299 	di = devm_kzalloc(dev, sizeof(struct mp886x_device_info), GFP_KERNEL);
300 	if (!di)
301 		return -ENOMEM;
302 
303 	di->regulator = of_get_regulator_init_data(dev, np, &di->desc);
304 	if (!di->regulator) {
305 		dev_err(dev, "Platform data not found!\n");
306 		return -EINVAL;
307 	}
308 
309 	ret = of_property_read_u32_array(np, "mps,fb-voltage-divider",
310 					 di->r, 2);
311 	if (ret)
312 		return ret;
313 
314 	di->en_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
315 	if (IS_ERR(di->en_gpio))
316 		return PTR_ERR(di->en_gpio);
317 
318 	di->ci = of_device_get_match_data(dev);
319 	di->dev = dev;
320 
321 	regmap = devm_regmap_init_i2c(client, &mp886x_regmap_config);
322 	if (IS_ERR(regmap)) {
323 		dev_err(dev, "Failed to allocate regmap!\n");
324 		return PTR_ERR(regmap);
325 	}
326 	i2c_set_clientdata(client, di);
327 
328 	config.dev = di->dev;
329 	config.init_data = di->regulator;
330 	config.regmap = regmap;
331 	config.driver_data = di;
332 	config.of_node = np;
333 
334 	if (!of_property_read_u32(np, "mps,switch-frequency-hz", &freq))
335 		mp886x_set_switch_freq(di, regmap, freq);
336 
337 	ret = mp886x_regulator_register(di, &config);
338 	if (ret < 0)
339 		dev_err(dev, "Failed to register regulator!\n");
340 	return ret;
341 }
342 
343 static const struct of_device_id mp886x_dt_ids[] = {
344 	{
345 		.compatible = "mps,mp8867",
346 		.data = &mp8867_ci
347 	},
348 	{
349 		.compatible = "mps,mp8869",
350 		.data = &mp8869_ci
351 	},
352 	{ }
353 };
354 MODULE_DEVICE_TABLE(of, mp886x_dt_ids);
355 
356 static const struct i2c_device_id mp886x_id[] = {
357 	{ "mp886x", },
358 	{ },
359 };
360 MODULE_DEVICE_TABLE(i2c, mp886x_id);
361 
362 static struct i2c_driver mp886x_regulator_driver = {
363 	.driver = {
364 		.name = "mp886x-regulator",
365 		.of_match_table = of_match_ptr(mp886x_dt_ids),
366 	},
367 	.probe_new = mp886x_i2c_probe,
368 	.id_table = mp886x_id,
369 };
370 module_i2c_driver(mp886x_regulator_driver);
371 
372 MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
373 MODULE_DESCRIPTION("MP886x regulator driver");
374 MODULE_LICENSE("GPL v2");
375