xref: /openbmc/linux/drivers/iio/adc/mt6370-adc.c (revision cabce92d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2022 Richtek Technology Corp.
4  *
5  * Author: ChiaEn Wu <chiaen_wu@richtek.com>
6  */
7 
8 #include <linux/bits.h>
9 #include <linux/bitfield.h>
10 #include <linux/iio/iio.h>
11 #include <linux/kernel.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/sysfs.h>
18 #include <linux/units.h>
19 
20 #include <dt-bindings/iio/adc/mediatek,mt6370_adc.h>
21 
22 #define MT6370_REG_DEV_INFO		0x100
23 #define MT6370_REG_CHG_CTRL3		0x113
24 #define MT6370_REG_CHG_CTRL7		0x117
25 #define MT6370_REG_CHG_ADC		0x121
26 #define MT6370_REG_ADC_DATA_H		0x14C
27 
28 #define MT6370_ADC_START_MASK		BIT(0)
29 #define MT6370_ADC_IN_SEL_MASK		GENMASK(7, 4)
30 #define MT6370_AICR_ICHG_MASK		GENMASK(7, 2)
31 #define MT6370_VENID_MASK		GENMASK(7, 4)
32 
33 #define MT6370_AICR_100_mA		0x0
34 #define MT6370_AICR_150_mA		0x1
35 #define MT6370_AICR_200_mA		0x2
36 #define MT6370_AICR_250_mA		0x3
37 #define MT6370_AICR_300_mA		0x4
38 #define MT6370_AICR_350_mA		0x5
39 
40 #define MT6370_ICHG_100_mA		0x0
41 #define MT6370_ICHG_200_mA		0x1
42 #define MT6370_ICHG_300_mA		0x2
43 #define MT6370_ICHG_400_mA		0x3
44 #define MT6370_ICHG_500_mA		0x4
45 #define MT6370_ICHG_600_mA		0x5
46 #define MT6370_ICHG_700_mA		0x6
47 #define MT6370_ICHG_800_mA		0x7
48 
49 #define ADC_CONV_TIME_MS		35
50 #define ADC_CONV_POLLING_TIME_US	1000
51 
52 #define MT6370_VID_RT5081		0x8
53 #define MT6370_VID_RT5081A		0xA
54 #define MT6370_VID_MT6370		0xE
55 
56 struct mt6370_adc_data {
57 	struct device *dev;
58 	struct regmap *regmap;
59 	/*
60 	 * This mutex lock is for preventing the different ADC channels
61 	 * from being read at the same time.
62 	 */
63 	struct mutex adc_lock;
64 	unsigned int vid;
65 };
66 
67 static int mt6370_adc_read_channel(struct mt6370_adc_data *priv, int chan,
68 				   unsigned long addr, int *val)
69 {
70 	unsigned int reg_val;
71 	__be16 be_val;
72 	int ret;
73 
74 	mutex_lock(&priv->adc_lock);
75 
76 	reg_val = MT6370_ADC_START_MASK |
77 		  FIELD_PREP(MT6370_ADC_IN_SEL_MASK, addr);
78 	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, reg_val);
79 	if (ret)
80 		goto adc_unlock;
81 
82 	msleep(ADC_CONV_TIME_MS);
83 
84 	ret = regmap_read_poll_timeout(priv->regmap,
85 				       MT6370_REG_CHG_ADC, reg_val,
86 				       !(reg_val & MT6370_ADC_START_MASK),
87 				       ADC_CONV_POLLING_TIME_US,
88 				       ADC_CONV_TIME_MS * MILLI * 3);
89 	if (ret) {
90 		dev_err(priv->dev, "Failed to read ADC register (%d)\n", ret);
91 		goto adc_unlock;
92 	}
93 
94 	ret = regmap_raw_read(priv->regmap, MT6370_REG_ADC_DATA_H,
95 			      &be_val, sizeof(be_val));
96 	if (ret)
97 		goto adc_unlock;
98 
99 	*val = be16_to_cpu(be_val);
100 	ret = IIO_VAL_INT;
101 
102 adc_unlock:
103 	mutex_unlock(&priv->adc_lock);
104 
105 	return ret;
106 }
107 
108 static int mt6370_adc_get_ibus_scale(struct mt6370_adc_data *priv)
109 {
110 	switch (priv->vid) {
111 	case MT6370_VID_RT5081:
112 	case MT6370_VID_RT5081A:
113 	case MT6370_VID_MT6370:
114 		return 3350;
115 	default:
116 		return 3875;
117 	}
118 }
119 
120 static int mt6370_adc_get_ibat_scale(struct mt6370_adc_data *priv)
121 {
122 	switch (priv->vid) {
123 	case MT6370_VID_RT5081:
124 	case MT6370_VID_RT5081A:
125 	case MT6370_VID_MT6370:
126 		return 2680;
127 	default:
128 		return 3870;
129 	}
130 }
131 
132 static int mt6370_adc_read_scale(struct mt6370_adc_data *priv,
133 				 int chan, int *val1, int *val2)
134 {
135 	unsigned int reg_val;
136 	int ret;
137 
138 	switch (chan) {
139 	case MT6370_CHAN_VBAT:
140 	case MT6370_CHAN_VSYS:
141 	case MT6370_CHAN_CHG_VDDP:
142 		*val1 = 5;
143 		return IIO_VAL_INT;
144 	case MT6370_CHAN_IBUS:
145 		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL3, &reg_val);
146 		if (ret)
147 			return ret;
148 
149 		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
150 		switch (reg_val) {
151 		case MT6370_AICR_100_mA:
152 		case MT6370_AICR_150_mA:
153 		case MT6370_AICR_200_mA:
154 		case MT6370_AICR_250_mA:
155 		case MT6370_AICR_300_mA:
156 		case MT6370_AICR_350_mA:
157 			*val1 = mt6370_adc_get_ibus_scale(priv);
158 			break;
159 		default:
160 			*val1 = 5000;
161 			break;
162 		}
163 
164 		*val2 = 100;
165 
166 		return IIO_VAL_FRACTIONAL;
167 	case MT6370_CHAN_IBAT:
168 		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL7, &reg_val);
169 		if (ret)
170 			return ret;
171 
172 		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
173 		switch (reg_val) {
174 		case MT6370_ICHG_100_mA:
175 		case MT6370_ICHG_200_mA:
176 		case MT6370_ICHG_300_mA:
177 		case MT6370_ICHG_400_mA:
178 			*val1 = 2375;
179 			break;
180 		case MT6370_ICHG_500_mA:
181 		case MT6370_ICHG_600_mA:
182 		case MT6370_ICHG_700_mA:
183 		case MT6370_ICHG_800_mA:
184 			*val1 = mt6370_adc_get_ibat_scale(priv);
185 			break;
186 		default:
187 			*val1 = 5000;
188 			break;
189 		}
190 
191 		*val2 = 100;
192 
193 		return IIO_VAL_FRACTIONAL;
194 	case MT6370_CHAN_VBUSDIV5:
195 		*val1 = 25;
196 		return IIO_VAL_INT;
197 	case MT6370_CHAN_VBUSDIV2:
198 		*val1 = 10;
199 		return IIO_VAL_INT;
200 	case MT6370_CHAN_TS_BAT:
201 		*val1 = 25;
202 		*val2 = 10000;
203 		return IIO_VAL_FRACTIONAL;
204 	case MT6370_CHAN_TEMP_JC:
205 		*val1 = 2000;
206 		return IIO_VAL_INT;
207 	default:
208 		return -EINVAL;
209 	}
210 }
211 
212 static int mt6370_adc_read_offset(struct mt6370_adc_data *priv,
213 				  int chan, int *val)
214 {
215 	*val = -20;
216 
217 	return IIO_VAL_INT;
218 }
219 
220 static int mt6370_adc_read_raw(struct iio_dev *iio_dev,
221 			       const struct iio_chan_spec *chan,
222 			       int *val, int *val2, long mask)
223 {
224 	struct mt6370_adc_data *priv = iio_priv(iio_dev);
225 
226 	switch (mask) {
227 	case IIO_CHAN_INFO_RAW:
228 		return mt6370_adc_read_channel(priv, chan->channel,
229 					       chan->address, val);
230 	case IIO_CHAN_INFO_SCALE:
231 		return mt6370_adc_read_scale(priv, chan->channel, val, val2);
232 	case IIO_CHAN_INFO_OFFSET:
233 		return mt6370_adc_read_offset(priv, chan->channel, val);
234 	default:
235 		return -EINVAL;
236 	}
237 }
238 
239 static const char * const mt6370_channel_labels[MT6370_CHAN_MAX] = {
240 	[MT6370_CHAN_VBUSDIV5] = "vbusdiv5",
241 	[MT6370_CHAN_VBUSDIV2] = "vbusdiv2",
242 	[MT6370_CHAN_VSYS] = "vsys",
243 	[MT6370_CHAN_VBAT] = "vbat",
244 	[MT6370_CHAN_TS_BAT] = "ts_bat",
245 	[MT6370_CHAN_IBUS] = "ibus",
246 	[MT6370_CHAN_IBAT] = "ibat",
247 	[MT6370_CHAN_CHG_VDDP] = "chg_vddp",
248 	[MT6370_CHAN_TEMP_JC] = "temp_jc",
249 };
250 
251 static int mt6370_adc_read_label(struct iio_dev *iio_dev,
252 				 struct iio_chan_spec const *chan, char *label)
253 {
254 	return sysfs_emit(label, "%s\n", mt6370_channel_labels[chan->channel]);
255 }
256 
257 static const struct iio_info mt6370_adc_iio_info = {
258 	.read_raw = mt6370_adc_read_raw,
259 	.read_label = mt6370_adc_read_label,
260 };
261 
262 #define MT6370_ADC_CHAN(_idx, _type, _addr, _extra_info) {	\
263 	.type = _type,						\
264 	.channel = MT6370_CHAN_##_idx,				\
265 	.address = _addr,					\
266 	.scan_index = MT6370_CHAN_##_idx,			\
267 	.indexed = 1,						\
268 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
269 			      BIT(IIO_CHAN_INFO_SCALE) |	\
270 			      _extra_info,			\
271 }
272 
273 static const struct iio_chan_spec mt6370_adc_channels[] = {
274 	MT6370_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE, 1, 0),
275 	MT6370_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE, 2, 0),
276 	MT6370_ADC_CHAN(VSYS, IIO_VOLTAGE, 3, 0),
277 	MT6370_ADC_CHAN(VBAT, IIO_VOLTAGE, 4, 0),
278 	MT6370_ADC_CHAN(TS_BAT, IIO_VOLTAGE, 6, 0),
279 	MT6370_ADC_CHAN(IBUS, IIO_CURRENT, 8, 0),
280 	MT6370_ADC_CHAN(IBAT, IIO_CURRENT, 9, 0),
281 	MT6370_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE, 11, 0),
282 	MT6370_ADC_CHAN(TEMP_JC, IIO_TEMP, 12, BIT(IIO_CHAN_INFO_OFFSET)),
283 };
284 
285 static int mt6370_get_vendor_info(struct mt6370_adc_data *priv)
286 {
287 	unsigned int dev_info;
288 	int ret;
289 
290 	ret = regmap_read(priv->regmap, MT6370_REG_DEV_INFO, &dev_info);
291 	if (ret)
292 		return ret;
293 
294 	priv->vid = FIELD_GET(MT6370_VENID_MASK, dev_info);
295 
296 	return 0;
297 }
298 
299 static int mt6370_adc_probe(struct platform_device *pdev)
300 {
301 	struct device *dev = &pdev->dev;
302 	struct mt6370_adc_data *priv;
303 	struct iio_dev *indio_dev;
304 	struct regmap *regmap;
305 	int ret;
306 
307 	regmap = dev_get_regmap(pdev->dev.parent, NULL);
308 	if (!regmap)
309 		return dev_err_probe(dev, -ENODEV, "Failed to get regmap\n");
310 
311 	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
312 	if (!indio_dev)
313 		return -ENOMEM;
314 
315 	priv = iio_priv(indio_dev);
316 	priv->dev = dev;
317 	priv->regmap = regmap;
318 	mutex_init(&priv->adc_lock);
319 
320 	ret = mt6370_get_vendor_info(priv);
321 	if (ret)
322 		return dev_err_probe(dev, ret, "Failed to get vid\n");
323 
324 	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, 0);
325 	if (ret)
326 		return dev_err_probe(dev, ret, "Failed to reset ADC\n");
327 
328 	indio_dev->name = "mt6370-adc";
329 	indio_dev->info = &mt6370_adc_iio_info;
330 	indio_dev->modes = INDIO_DIRECT_MODE;
331 	indio_dev->channels = mt6370_adc_channels;
332 	indio_dev->num_channels = ARRAY_SIZE(mt6370_adc_channels);
333 
334 	return devm_iio_device_register(dev, indio_dev);
335 }
336 
337 static const struct of_device_id mt6370_adc_of_id[] = {
338 	{ .compatible = "mediatek,mt6370-adc", },
339 	{}
340 };
341 MODULE_DEVICE_TABLE(of, mt6370_adc_of_id);
342 
343 static struct platform_driver mt6370_adc_driver = {
344 	.driver = {
345 		.name = "mt6370-adc",
346 		.of_match_table = mt6370_adc_of_id,
347 	},
348 	.probe = mt6370_adc_probe,
349 };
350 module_platform_driver(mt6370_adc_driver);
351 
352 MODULE_AUTHOR("ChiaEn Wu <chiaen_wu@richtek.com>");
353 MODULE_DESCRIPTION("MT6370 ADC Driver");
354 MODULE_LICENSE("GPL v2");
355