1 /*
2 * TI LP8788 MFD - ADC driver
3 *
4 * Copyright 2012 Texas Instruments
5 *
6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/delay.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/driver.h>
16 #include <linux/iio/machine.h>
17 #include <linux/mfd/lp8788.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22
23 /* register address */
24 #define LP8788_ADC_CONF 0x60
25 #define LP8788_ADC_RAW 0x61
26 #define LP8788_ADC_DONE 0x63
27
28 #define ADC_CONV_START 1
29
30 struct lp8788_adc {
31 struct lp8788 *lp;
32 struct iio_map *map;
33 struct mutex lock;
34 };
35
36 static const int lp8788_scale[LPADC_MAX] = {
37 [LPADC_VBATT_5P5] = 1343101,
38 [LPADC_VIN_CHG] = 3052503,
39 [LPADC_IBATT] = 610500,
40 [LPADC_IC_TEMP] = 61050,
41 [LPADC_VBATT_6P0] = 1465201,
42 [LPADC_VBATT_5P0] = 1221001,
43 [LPADC_ADC1] = 610500,
44 [LPADC_ADC2] = 610500,
45 [LPADC_VDD] = 1025641,
46 [LPADC_VCOIN] = 757020,
47 [LPADC_ADC3] = 610500,
48 [LPADC_ADC4] = 610500,
49 };
50
lp8788_get_adc_result(struct lp8788_adc * adc,enum lp8788_adc_id id,int * val)51 static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id,
52 int *val)
53 {
54 unsigned int msb;
55 unsigned int lsb;
56 unsigned int result;
57 u8 data;
58 u8 rawdata[2];
59 int size = ARRAY_SIZE(rawdata);
60 int retry = 5;
61 int ret;
62
63 data = (id << 1) | ADC_CONV_START;
64 ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data);
65 if (ret)
66 goto err_io;
67
68 /* retry until adc conversion is done */
69 data = 0;
70 while (retry--) {
71 usleep_range(100, 200);
72
73 ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data);
74 if (ret)
75 goto err_io;
76
77 /* conversion done */
78 if (data)
79 break;
80 }
81
82 ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size);
83 if (ret)
84 goto err_io;
85
86 msb = (rawdata[0] << 4) & 0x00000ff0;
87 lsb = (rawdata[1] >> 4) & 0x0000000f;
88 result = msb | lsb;
89 *val = result;
90
91 return 0;
92
93 err_io:
94 return ret;
95 }
96
lp8788_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)97 static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
98 struct iio_chan_spec const *chan,
99 int *val, int *val2, long mask)
100 {
101 struct lp8788_adc *adc = iio_priv(indio_dev);
102 enum lp8788_adc_id id = chan->channel;
103 int ret;
104
105 mutex_lock(&adc->lock);
106
107 switch (mask) {
108 case IIO_CHAN_INFO_RAW:
109 ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT;
110 break;
111 case IIO_CHAN_INFO_SCALE:
112 *val = lp8788_scale[id] / 1000000;
113 *val2 = lp8788_scale[id] % 1000000;
114 ret = IIO_VAL_INT_PLUS_MICRO;
115 break;
116 default:
117 ret = -EINVAL;
118 break;
119 }
120
121 mutex_unlock(&adc->lock);
122
123 return ret;
124 }
125
126 static const struct iio_info lp8788_adc_info = {
127 .read_raw = &lp8788_adc_read_raw,
128 };
129
130 #define LP8788_CHAN(_id, _type) { \
131 .type = _type, \
132 .indexed = 1, \
133 .channel = LPADC_##_id, \
134 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
135 BIT(IIO_CHAN_INFO_SCALE), \
136 .datasheet_name = #_id, \
137 }
138
139 static const struct iio_chan_spec lp8788_adc_channels[] = {
140 [LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE),
141 [LPADC_VIN_CHG] = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE),
142 [LPADC_IBATT] = LP8788_CHAN(IBATT, IIO_CURRENT),
143 [LPADC_IC_TEMP] = LP8788_CHAN(IC_TEMP, IIO_TEMP),
144 [LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE),
145 [LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE),
146 [LPADC_ADC1] = LP8788_CHAN(ADC1, IIO_VOLTAGE),
147 [LPADC_ADC2] = LP8788_CHAN(ADC2, IIO_VOLTAGE),
148 [LPADC_VDD] = LP8788_CHAN(VDD, IIO_VOLTAGE),
149 [LPADC_VCOIN] = LP8788_CHAN(VCOIN, IIO_VOLTAGE),
150 [LPADC_ADC3] = LP8788_CHAN(ADC3, IIO_VOLTAGE),
151 [LPADC_ADC4] = LP8788_CHAN(ADC4, IIO_VOLTAGE),
152 };
153
154 /* default maps used by iio consumer (lp8788-charger driver) */
155 static struct iio_map lp8788_default_iio_maps[] = {
156 {
157 .consumer_dev_name = "lp8788-charger",
158 .consumer_channel = "lp8788_vbatt_5p0",
159 .adc_channel_label = "VBATT_5P0",
160 },
161 {
162 .consumer_dev_name = "lp8788-charger",
163 .consumer_channel = "lp8788_adc1",
164 .adc_channel_label = "ADC1",
165 },
166 { }
167 };
168
lp8788_iio_map_register(struct iio_dev * indio_dev,struct lp8788_platform_data * pdata,struct lp8788_adc * adc)169 static int lp8788_iio_map_register(struct iio_dev *indio_dev,
170 struct lp8788_platform_data *pdata,
171 struct lp8788_adc *adc)
172 {
173 struct iio_map *map;
174 int ret;
175
176 map = (!pdata || !pdata->adc_pdata) ?
177 lp8788_default_iio_maps : pdata->adc_pdata;
178
179 ret = iio_map_array_register(indio_dev, map);
180 if (ret) {
181 dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
182 return ret;
183 }
184
185 adc->map = map;
186 return 0;
187 }
188
lp8788_adc_probe(struct platform_device * pdev)189 static int lp8788_adc_probe(struct platform_device *pdev)
190 {
191 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
192 struct iio_dev *indio_dev;
193 struct lp8788_adc *adc;
194 int ret;
195
196 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
197 if (!indio_dev)
198 return -ENOMEM;
199
200 adc = iio_priv(indio_dev);
201 adc->lp = lp;
202 platform_set_drvdata(pdev, indio_dev);
203
204 indio_dev->dev.of_node = pdev->dev.of_node;
205 ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc);
206 if (ret)
207 return ret;
208
209 mutex_init(&adc->lock);
210
211 indio_dev->dev.parent = &pdev->dev;
212 indio_dev->name = pdev->name;
213 indio_dev->modes = INDIO_DIRECT_MODE;
214 indio_dev->info = &lp8788_adc_info;
215 indio_dev->channels = lp8788_adc_channels;
216 indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);
217
218 ret = iio_device_register(indio_dev);
219 if (ret) {
220 dev_err(&pdev->dev, "iio dev register err: %d\n", ret);
221 goto err_iio_device;
222 }
223
224 return 0;
225
226 err_iio_device:
227 iio_map_array_unregister(indio_dev);
228 return ret;
229 }
230
lp8788_adc_remove(struct platform_device * pdev)231 static int lp8788_adc_remove(struct platform_device *pdev)
232 {
233 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
234
235 iio_device_unregister(indio_dev);
236 iio_map_array_unregister(indio_dev);
237
238 return 0;
239 }
240
241 static struct platform_driver lp8788_adc_driver = {
242 .probe = lp8788_adc_probe,
243 .remove = lp8788_adc_remove,
244 .driver = {
245 .name = LP8788_DEV_ADC,
246 },
247 };
248 module_platform_driver(lp8788_adc_driver);
249
250 MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
251 MODULE_AUTHOR("Milo Kim");
252 MODULE_LICENSE("GPL");
253 MODULE_ALIAS("platform:lp8788-adc");
254
