xref: /linux/drivers/iio/adc/mt6370-adc.c (revision 07f0148aafe8c95a3a76cd59e9e75b4d78d1d31d)
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_CHG_CTRL3		0x113
23 #define MT6370_REG_CHG_CTRL7		0x117
24 #define MT6370_REG_CHG_ADC		0x121
25 #define MT6370_REG_ADC_DATA_H		0x14C
26 
27 #define MT6370_ADC_START_MASK		BIT(0)
28 #define MT6370_ADC_IN_SEL_MASK		GENMASK(7, 4)
29 #define MT6370_AICR_ICHG_MASK		GENMASK(7, 2)
30 
31 #define MT6370_AICR_100_mA		0x0
32 #define MT6370_AICR_150_mA		0x1
33 #define MT6370_AICR_200_mA		0x2
34 #define MT6370_AICR_250_mA		0x3
35 #define MT6370_AICR_300_mA		0x4
36 #define MT6370_AICR_350_mA		0x5
37 
38 #define MT6370_ICHG_100_mA		0x0
39 #define MT6370_ICHG_200_mA		0x1
40 #define MT6370_ICHG_300_mA		0x2
41 #define MT6370_ICHG_400_mA		0x3
42 #define MT6370_ICHG_500_mA		0x4
43 #define MT6370_ICHG_600_mA		0x5
44 #define MT6370_ICHG_700_mA		0x6
45 #define MT6370_ICHG_800_mA		0x7
46 
47 #define ADC_CONV_TIME_MS		35
48 #define ADC_CONV_POLLING_TIME_US	1000
49 
50 struct mt6370_adc_data {
51 	struct device *dev;
52 	struct regmap *regmap;
53 	/*
54 	 * This mutex lock is for preventing the different ADC channels
55 	 * from being read at the same time.
56 	 */
57 	struct mutex adc_lock;
58 };
59 
60 static int mt6370_adc_read_channel(struct mt6370_adc_data *priv, int chan,
61 				   unsigned long addr, int *val)
62 {
63 	unsigned int reg_val;
64 	__be16 be_val;
65 	int ret;
66 
67 	mutex_lock(&priv->adc_lock);
68 
69 	reg_val = MT6370_ADC_START_MASK |
70 		  FIELD_PREP(MT6370_ADC_IN_SEL_MASK, addr);
71 	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, reg_val);
72 	if (ret)
73 		goto adc_unlock;
74 
75 	msleep(ADC_CONV_TIME_MS);
76 
77 	ret = regmap_read_poll_timeout(priv->regmap,
78 				       MT6370_REG_CHG_ADC, reg_val,
79 				       !(reg_val & MT6370_ADC_START_MASK),
80 				       ADC_CONV_POLLING_TIME_US,
81 				       ADC_CONV_TIME_MS * MILLI * 3);
82 	if (ret) {
83 		dev_err(priv->dev, "Failed to read ADC register (%d)\n", ret);
84 		goto adc_unlock;
85 	}
86 
87 	ret = regmap_raw_read(priv->regmap, MT6370_REG_ADC_DATA_H,
88 			      &be_val, sizeof(be_val));
89 	if (ret)
90 		goto adc_unlock;
91 
92 	*val = be16_to_cpu(be_val);
93 	ret = IIO_VAL_INT;
94 
95 adc_unlock:
96 	mutex_unlock(&priv->adc_lock);
97 
98 	return ret;
99 }
100 
101 static int mt6370_adc_read_scale(struct mt6370_adc_data *priv,
102 				 int chan, int *val1, int *val2)
103 {
104 	unsigned int reg_val;
105 	int ret;
106 
107 	switch (chan) {
108 	case MT6370_CHAN_VBAT:
109 	case MT6370_CHAN_VSYS:
110 	case MT6370_CHAN_CHG_VDDP:
111 		*val1 = 5;
112 		return IIO_VAL_INT;
113 	case MT6370_CHAN_IBUS:
114 		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL3, &reg_val);
115 		if (ret)
116 			return ret;
117 
118 		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
119 		switch (reg_val) {
120 		case MT6370_AICR_100_mA:
121 		case MT6370_AICR_150_mA:
122 		case MT6370_AICR_200_mA:
123 		case MT6370_AICR_250_mA:
124 		case MT6370_AICR_300_mA:
125 		case MT6370_AICR_350_mA:
126 			*val1 = 3350;
127 			break;
128 		default:
129 			*val1 = 5000;
130 			break;
131 		}
132 
133 		*val2 = 100;
134 
135 		return IIO_VAL_FRACTIONAL;
136 	case MT6370_CHAN_IBAT:
137 		ret = regmap_read(priv->regmap, MT6370_REG_CHG_CTRL7, &reg_val);
138 		if (ret)
139 			return ret;
140 
141 		reg_val = FIELD_GET(MT6370_AICR_ICHG_MASK, reg_val);
142 		switch (reg_val) {
143 		case MT6370_ICHG_100_mA:
144 		case MT6370_ICHG_200_mA:
145 		case MT6370_ICHG_300_mA:
146 		case MT6370_ICHG_400_mA:
147 			*val1 = 2375;
148 			break;
149 		case MT6370_ICHG_500_mA:
150 		case MT6370_ICHG_600_mA:
151 		case MT6370_ICHG_700_mA:
152 		case MT6370_ICHG_800_mA:
153 			*val1 = 2680;
154 			break;
155 		default:
156 			*val1 = 5000;
157 			break;
158 		}
159 
160 		*val2 = 100;
161 
162 		return IIO_VAL_FRACTIONAL;
163 	case MT6370_CHAN_VBUSDIV5:
164 		*val1 = 25;
165 		return IIO_VAL_INT;
166 	case MT6370_CHAN_VBUSDIV2:
167 		*val1 = 10;
168 		return IIO_VAL_INT;
169 	case MT6370_CHAN_TS_BAT:
170 		*val1 = 25;
171 		*val2 = 10000;
172 		return IIO_VAL_FRACTIONAL;
173 	case MT6370_CHAN_TEMP_JC:
174 		*val1 = 2000;
175 		return IIO_VAL_INT;
176 	default:
177 		return -EINVAL;
178 	}
179 }
180 
181 static int mt6370_adc_read_offset(struct mt6370_adc_data *priv,
182 				  int chan, int *val)
183 {
184 	*val = -20;
185 
186 	return IIO_VAL_INT;
187 }
188 
189 static int mt6370_adc_read_raw(struct iio_dev *iio_dev,
190 			       const struct iio_chan_spec *chan,
191 			       int *val, int *val2, long mask)
192 {
193 	struct mt6370_adc_data *priv = iio_priv(iio_dev);
194 
195 	switch (mask) {
196 	case IIO_CHAN_INFO_RAW:
197 		return mt6370_adc_read_channel(priv, chan->channel,
198 					       chan->address, val);
199 	case IIO_CHAN_INFO_SCALE:
200 		return mt6370_adc_read_scale(priv, chan->channel, val, val2);
201 	case IIO_CHAN_INFO_OFFSET:
202 		return mt6370_adc_read_offset(priv, chan->channel, val);
203 	default:
204 		return -EINVAL;
205 	}
206 }
207 
208 static const char * const mt6370_channel_labels[MT6370_CHAN_MAX] = {
209 	[MT6370_CHAN_VBUSDIV5] = "vbusdiv5",
210 	[MT6370_CHAN_VBUSDIV2] = "vbusdiv2",
211 	[MT6370_CHAN_VSYS] = "vsys",
212 	[MT6370_CHAN_VBAT] = "vbat",
213 	[MT6370_CHAN_TS_BAT] = "ts_bat",
214 	[MT6370_CHAN_IBUS] = "ibus",
215 	[MT6370_CHAN_IBAT] = "ibat",
216 	[MT6370_CHAN_CHG_VDDP] = "chg_vddp",
217 	[MT6370_CHAN_TEMP_JC] = "temp_jc",
218 };
219 
220 static int mt6370_adc_read_label(struct iio_dev *iio_dev,
221 				 struct iio_chan_spec const *chan, char *label)
222 {
223 	return sysfs_emit(label, "%s\n", mt6370_channel_labels[chan->channel]);
224 }
225 
226 static const struct iio_info mt6370_adc_iio_info = {
227 	.read_raw = mt6370_adc_read_raw,
228 	.read_label = mt6370_adc_read_label,
229 };
230 
231 #define MT6370_ADC_CHAN(_idx, _type, _addr, _extra_info) {	\
232 	.type = _type,						\
233 	.channel = MT6370_CHAN_##_idx,				\
234 	.address = _addr,					\
235 	.scan_index = MT6370_CHAN_##_idx,			\
236 	.indexed = 1,						\
237 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
238 			      BIT(IIO_CHAN_INFO_SCALE) |	\
239 			      _extra_info,			\
240 }
241 
242 static const struct iio_chan_spec mt6370_adc_channels[] = {
243 	MT6370_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE, 1, 0),
244 	MT6370_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE, 2, 0),
245 	MT6370_ADC_CHAN(VSYS, IIO_VOLTAGE, 3, 0),
246 	MT6370_ADC_CHAN(VBAT, IIO_VOLTAGE, 4, 0),
247 	MT6370_ADC_CHAN(TS_BAT, IIO_VOLTAGE, 6, 0),
248 	MT6370_ADC_CHAN(IBUS, IIO_CURRENT, 8, 0),
249 	MT6370_ADC_CHAN(IBAT, IIO_CURRENT, 9, 0),
250 	MT6370_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE, 11, 0),
251 	MT6370_ADC_CHAN(TEMP_JC, IIO_TEMP, 12, BIT(IIO_CHAN_INFO_OFFSET)),
252 };
253 
254 static int mt6370_adc_probe(struct platform_device *pdev)
255 {
256 	struct device *dev = &pdev->dev;
257 	struct mt6370_adc_data *priv;
258 	struct iio_dev *indio_dev;
259 	struct regmap *regmap;
260 	int ret;
261 
262 	regmap = dev_get_regmap(pdev->dev.parent, NULL);
263 	if (!regmap)
264 		return dev_err_probe(dev, -ENODEV, "Failed to get regmap\n");
265 
266 	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
267 	if (!indio_dev)
268 		return -ENOMEM;
269 
270 	priv = iio_priv(indio_dev);
271 	priv->dev = dev;
272 	priv->regmap = regmap;
273 	mutex_init(&priv->adc_lock);
274 
275 	ret = regmap_write(priv->regmap, MT6370_REG_CHG_ADC, 0);
276 	if (ret)
277 		return dev_err_probe(dev, ret, "Failed to reset ADC\n");
278 
279 	indio_dev->name = "mt6370-adc";
280 	indio_dev->info = &mt6370_adc_iio_info;
281 	indio_dev->modes = INDIO_DIRECT_MODE;
282 	indio_dev->channels = mt6370_adc_channels;
283 	indio_dev->num_channels = ARRAY_SIZE(mt6370_adc_channels);
284 
285 	return devm_iio_device_register(dev, indio_dev);
286 }
287 
288 static const struct of_device_id mt6370_adc_of_id[] = {
289 	{ .compatible = "mediatek,mt6370-adc", },
290 	{}
291 };
292 MODULE_DEVICE_TABLE(of, mt6370_adc_of_id);
293 
294 static struct platform_driver mt6370_adc_driver = {
295 	.driver = {
296 		.name = "mt6370-adc",
297 		.of_match_table = mt6370_adc_of_id,
298 	},
299 	.probe = mt6370_adc_probe,
300 };
301 module_platform_driver(mt6370_adc_driver);
302 
303 MODULE_AUTHOR("ChiaEn Wu <chiaen_wu@richtek.com>");
304 MODULE_DESCRIPTION("MT6370 ADC Driver");
305 MODULE_LICENSE("GPL v2");
306