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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * TI LP8788 MFD - ADC driver4 *5 * Copyright 2012 Texas Instruments6 *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 0x6022#define LP8788_ADC_RAW 0x6123#define LP8788_ADC_DONE 0x6324 25#define ADC_CONV_START 126 27struct lp8788_adc {28 struct lp8788 *lp;29 struct iio_map *map;30 struct mutex lock;31};32 33static 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 48static 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(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(100, 200);69 70 ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &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(adc->lp, LP8788_ADC_RAW, rawdata, 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 90err_io:91 return ret;92}93 94static 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(&adc->lock);119 120 return ret;121}122 123static 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 136static 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) */152static 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 166static 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, 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 187static int lp8788_adc_probe(struct platform_device *pdev)188{189 struct lp8788 *lp = dev_get_drvdata(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(&pdev->dev, 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(&pdev->dev, indio_dev, 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 216static struct platform_driver lp8788_adc_driver = {217 .probe = lp8788_adc_probe,218 .driver = {219 .name = LP8788_DEV_ADC,220 },221};222module_platform_driver(lp8788_adc_driver);223 224MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");225MODULE_AUTHOR("Milo Kim");226MODULE_LICENSE("GPL");227MODULE_ALIAS("platform:lp8788-adc");228