1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * TI LP8788 MFD - ADC driver |
4 | * |
5 | * Copyright 2012 Texas Instruments |
6 | * |
7 | * Author: Milo(Woogyom) Kim <milo.kim@ti.com> |
8 | */ |
9 | |
10 | #include <linux/delay.h> |
11 | #include <linux/iio/iio.h> |
12 | #include <linux/iio/driver.h> |
13 | #include <linux/iio/machine.h> |
14 | #include <linux/mfd/lp8788.h> |
15 | #include <linux/module.h> |
16 | #include <linux/mutex.h> |
17 | #include <linux/platform_device.h> |
18 | #include <linux/slab.h> |
19 | |
20 | /* register address */ |
21 | #define LP8788_ADC_CONF 0x60 |
22 | #define LP8788_ADC_RAW 0x61 |
23 | #define LP8788_ADC_DONE 0x63 |
24 | |
25 | #define ADC_CONV_START 1 |
26 | |
27 | struct lp8788_adc { |
28 | struct lp8788 *lp; |
29 | struct iio_map *map; |
30 | struct mutex lock; |
31 | }; |
32 | |
33 | static const int lp8788_scale[LPADC_MAX] = { |
34 | [LPADC_VBATT_5P5] = 1343101, |
35 | [LPADC_VIN_CHG] = 3052503, |
36 | [LPADC_IBATT] = 610500, |
37 | [LPADC_IC_TEMP] = 61050, |
38 | [LPADC_VBATT_6P0] = 1465201, |
39 | [LPADC_VBATT_5P0] = 1221001, |
40 | [LPADC_ADC1] = 610500, |
41 | [LPADC_ADC2] = 610500, |
42 | [LPADC_VDD] = 1025641, |
43 | [LPADC_VCOIN] = 757020, |
44 | [LPADC_ADC3] = 610500, |
45 | [LPADC_ADC4] = 610500, |
46 | }; |
47 | |
48 | static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id, |
49 | int *val) |
50 | { |
51 | unsigned int msb; |
52 | unsigned int lsb; |
53 | unsigned int result; |
54 | u8 data; |
55 | u8 rawdata[2]; |
56 | int size = ARRAY_SIZE(rawdata); |
57 | int retry = 5; |
58 | int ret; |
59 | |
60 | data = (id << 1) | ADC_CONV_START; |
61 | ret = lp8788_write_byte(lp: adc->lp, LP8788_ADC_CONF, data); |
62 | if (ret) |
63 | goto err_io; |
64 | |
65 | /* retry until adc conversion is done */ |
66 | data = 0; |
67 | while (retry--) { |
68 | usleep_range(min: 100, max: 200); |
69 | |
70 | ret = lp8788_read_byte(lp: adc->lp, LP8788_ADC_DONE, data: &data); |
71 | if (ret) |
72 | goto err_io; |
73 | |
74 | /* conversion done */ |
75 | if (data) |
76 | break; |
77 | } |
78 | |
79 | ret = lp8788_read_multi_bytes(lp: adc->lp, LP8788_ADC_RAW, data: rawdata, count: size); |
80 | if (ret) |
81 | goto err_io; |
82 | |
83 | msb = (rawdata[0] << 4) & 0x00000ff0; |
84 | lsb = (rawdata[1] >> 4) & 0x0000000f; |
85 | result = msb | lsb; |
86 | *val = result; |
87 | |
88 | return 0; |
89 | |
90 | err_io: |
91 | return ret; |
92 | } |
93 | |
94 | static int lp8788_adc_read_raw(struct iio_dev *indio_dev, |
95 | struct iio_chan_spec const *chan, |
96 | int *val, int *val2, long mask) |
97 | { |
98 | struct lp8788_adc *adc = iio_priv(indio_dev); |
99 | enum lp8788_adc_id id = chan->channel; |
100 | int ret; |
101 | |
102 | mutex_lock(&adc->lock); |
103 | |
104 | switch (mask) { |
105 | case IIO_CHAN_INFO_RAW: |
106 | ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT; |
107 | break; |
108 | case IIO_CHAN_INFO_SCALE: |
109 | *val = lp8788_scale[id] / 1000000; |
110 | *val2 = lp8788_scale[id] % 1000000; |
111 | ret = IIO_VAL_INT_PLUS_MICRO; |
112 | break; |
113 | default: |
114 | ret = -EINVAL; |
115 | break; |
116 | } |
117 | |
118 | mutex_unlock(lock: &adc->lock); |
119 | |
120 | return ret; |
121 | } |
122 | |
123 | static const struct iio_info lp8788_adc_info = { |
124 | .read_raw = &lp8788_adc_read_raw, |
125 | }; |
126 | |
127 | #define LP8788_CHAN(_id, _type) { \ |
128 | .type = _type, \ |
129 | .indexed = 1, \ |
130 | .channel = LPADC_##_id, \ |
131 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
132 | BIT(IIO_CHAN_INFO_SCALE), \ |
133 | .datasheet_name = #_id, \ |
134 | } |
135 | |
136 | static const struct iio_chan_spec lp8788_adc_channels[] = { |
137 | [LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE), |
138 | [LPADC_VIN_CHG] = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE), |
139 | [LPADC_IBATT] = LP8788_CHAN(IBATT, IIO_CURRENT), |
140 | [LPADC_IC_TEMP] = LP8788_CHAN(IC_TEMP, IIO_TEMP), |
141 | [LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE), |
142 | [LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE), |
143 | [LPADC_ADC1] = LP8788_CHAN(ADC1, IIO_VOLTAGE), |
144 | [LPADC_ADC2] = LP8788_CHAN(ADC2, IIO_VOLTAGE), |
145 | [LPADC_VDD] = LP8788_CHAN(VDD, IIO_VOLTAGE), |
146 | [LPADC_VCOIN] = LP8788_CHAN(VCOIN, IIO_VOLTAGE), |
147 | [LPADC_ADC3] = LP8788_CHAN(ADC3, IIO_VOLTAGE), |
148 | [LPADC_ADC4] = LP8788_CHAN(ADC4, IIO_VOLTAGE), |
149 | }; |
150 | |
151 | /* default maps used by iio consumer (lp8788-charger driver) */ |
152 | static struct iio_map lp8788_default_iio_maps[] = { |
153 | { |
154 | .consumer_dev_name = "lp8788-charger" , |
155 | .consumer_channel = "lp8788_vbatt_5p0" , |
156 | .adc_channel_label = "VBATT_5P0" , |
157 | }, |
158 | { |
159 | .consumer_dev_name = "lp8788-charger" , |
160 | .consumer_channel = "lp8788_adc1" , |
161 | .adc_channel_label = "ADC1" , |
162 | }, |
163 | { } |
164 | }; |
165 | |
166 | static int lp8788_iio_map_register(struct device *dev, |
167 | struct iio_dev *indio_dev, |
168 | struct lp8788_platform_data *pdata, |
169 | struct lp8788_adc *adc) |
170 | { |
171 | struct iio_map *map; |
172 | int ret; |
173 | |
174 | map = (!pdata || !pdata->adc_pdata) ? |
175 | lp8788_default_iio_maps : pdata->adc_pdata; |
176 | |
177 | ret = devm_iio_map_array_register(dev, indio_dev, maps: map); |
178 | if (ret) { |
179 | dev_err(&indio_dev->dev, "iio map err: %d\n" , ret); |
180 | return ret; |
181 | } |
182 | |
183 | adc->map = map; |
184 | return 0; |
185 | } |
186 | |
187 | static int lp8788_adc_probe(struct platform_device *pdev) |
188 | { |
189 | struct lp8788 *lp = dev_get_drvdata(dev: pdev->dev.parent); |
190 | struct iio_dev *indio_dev; |
191 | struct lp8788_adc *adc; |
192 | int ret; |
193 | |
194 | indio_dev = devm_iio_device_alloc(parent: &pdev->dev, sizeof_priv: sizeof(*adc)); |
195 | if (!indio_dev) |
196 | return -ENOMEM; |
197 | |
198 | adc = iio_priv(indio_dev); |
199 | adc->lp = lp; |
200 | |
201 | ret = lp8788_iio_map_register(dev: &pdev->dev, indio_dev, pdata: lp->pdata, adc); |
202 | if (ret) |
203 | return ret; |
204 | |
205 | mutex_init(&adc->lock); |
206 | |
207 | indio_dev->name = pdev->name; |
208 | indio_dev->modes = INDIO_DIRECT_MODE; |
209 | indio_dev->info = &lp8788_adc_info; |
210 | indio_dev->channels = lp8788_adc_channels; |
211 | indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels); |
212 | |
213 | return devm_iio_device_register(&pdev->dev, indio_dev); |
214 | } |
215 | |
216 | static struct platform_driver lp8788_adc_driver = { |
217 | .probe = lp8788_adc_probe, |
218 | .driver = { |
219 | .name = LP8788_DEV_ADC, |
220 | }, |
221 | }; |
222 | module_platform_driver(lp8788_adc_driver); |
223 | |
224 | MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver" ); |
225 | MODULE_AUTHOR("Milo Kim" ); |
226 | MODULE_LICENSE("GPL" ); |
227 | MODULE_ALIAS("platform:lp8788-adc" ); |
228 | |