lp8788_adc.c (5386B)
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 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");