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/*
* TI LP8788 MFD - ADC driver
*
* Copyright 2012 Texas Instruments
*
* Author: Milo(Woogyom) Kim <milo.kim@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/iio/machine.h>
#include <linux/mfd/lp8788.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
/* register address */
#define LP8788_ADC_CONF 0x60
#define LP8788_ADC_RAW 0x61
#define LP8788_ADC_DONE 0x63
#define ADC_CONV_START 1
struct lp8788_adc {
struct lp8788 *lp;
struct iio_map *map;
struct mutex lock;
};
static const int lp8788_scale[LPADC_MAX] = {
[LPADC_VBATT_5P5] = 1343101,
[LPADC_VIN_CHG] = 3052503,
[LPADC_IBATT] = 610500,
[LPADC_IC_TEMP] = 61050,
[LPADC_VBATT_6P0] = 1465201,
[LPADC_VBATT_5P0] = 1221001,
[LPADC_ADC1] = 610500,
[LPADC_ADC2] = 610500,
[LPADC_VDD] = 1025641,
[LPADC_VCOIN] = 757020,
[LPADC_ADC3] = 610500,
[LPADC_ADC4] = 610500,
};
static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id,
int *val)
{
unsigned int msb;
unsigned int lsb;
unsigned int result;
u8 data;
u8 rawdata[2];
int size = ARRAY_SIZE(rawdata);
int retry = 5;
int ret;
data = (id << 1) | ADC_CONV_START;
ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data);
if (ret)
goto err_io;
/* retry until adc conversion is done */
data = 0;
while (retry--) {
usleep_range(100, 200);
ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data);
if (ret)
goto err_io;
/* conversion done */
if (data)
break;
}
ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size);
if (ret)
goto err_io;
msb = (rawdata[0] << 4) & 0x00000ff0;
lsb = (rawdata[1] >> 4) & 0x0000000f;
result = msb | lsb;
*val = result;
return 0;
err_io:
return ret;
}
static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct lp8788_adc *adc = iio_priv(indio_dev);
enum lp8788_adc_id id = chan->channel;
int ret;
mutex_lock(&adc->lock);
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
*val = lp8788_scale[id] / 1000000;
*val2 = lp8788_scale[id] % 1000000;
ret = IIO_VAL_INT_PLUS_MICRO;
break;
default:
ret = -EINVAL;
break;
}
mutex_unlock(&adc->lock);
return ret;
}
static const struct iio_info lp8788_adc_info = {
.read_raw = &lp8788_adc_read_raw,
.driver_module = THIS_MODULE,
};
#define LP8788_CHAN(_id, _type) { \
.type = _type, \
.indexed = 1, \
.channel = LPADC_##_id, \
.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
IIO_CHAN_INFO_SCALE_SEPARATE_BIT, \
.datasheet_name = #_id, \
}
static const struct iio_chan_spec lp8788_adc_channels[] = {
[LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE),
[LPADC_VIN_CHG] = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE),
[LPADC_IBATT] = LP8788_CHAN(IBATT, IIO_CURRENT),
[LPADC_IC_TEMP] = LP8788_CHAN(IC_TEMP, IIO_TEMP),
[LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE),
[LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE),
[LPADC_ADC1] = LP8788_CHAN(ADC1, IIO_VOLTAGE),
[LPADC_ADC2] = LP8788_CHAN(ADC2, IIO_VOLTAGE),
[LPADC_VDD] = LP8788_CHAN(VDD, IIO_VOLTAGE),
[LPADC_VCOIN] = LP8788_CHAN(VCOIN, IIO_VOLTAGE),
[LPADC_ADC3] = LP8788_CHAN(ADC3, IIO_VOLTAGE),
[LPADC_ADC4] = LP8788_CHAN(ADC4, IIO_VOLTAGE),
};
/* default maps used by iio consumer (lp8788-charger driver) */
static struct iio_map lp8788_default_iio_maps[] = {
{
.consumer_dev_name = "lp8788-charger",
.consumer_channel = "lp8788_vbatt_5p0",
.adc_channel_label = "VBATT_5P0",
},
{
.consumer_dev_name = "lp8788-charger",
.consumer_channel = "lp8788_adc1",
.adc_channel_label = "ADC1",
},
{ }
};
static int lp8788_iio_map_register(struct iio_dev *indio_dev,
struct lp8788_platform_data *pdata,
struct lp8788_adc *adc)
{
struct iio_map *map;
int ret;
map = (!pdata || !pdata->adc_pdata) ?
lp8788_default_iio_maps : pdata->adc_pdata;
ret = iio_map_array_register(indio_dev, map);
if (ret) {
dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
return ret;
}
adc->map = map;
return 0;
}
static inline void lp8788_iio_map_unregister(struct iio_dev *indio_dev,
struct lp8788_adc *adc)
{
iio_map_array_unregister(indio_dev, adc->map);
}
static int lp8788_adc_probe(struct platform_device *pdev)
{
struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
struct iio_dev *indio_dev;
struct lp8788_adc *adc;
int ret;
indio_dev = iio_device_alloc(sizeof(*adc));
if (!indio_dev)
return -ENOMEM;
adc = iio_priv(indio_dev);
adc->lp = lp;
platform_set_drvdata(pdev, indio_dev);
ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc);
if (ret)
goto err_iio_map;
mutex_init(&adc->lock);
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = pdev->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &lp8788_adc_info;
indio_dev->channels = lp8788_adc_channels;
indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "iio dev register err: %d\n", ret);
goto err_iio_device;
}
return 0;
err_iio_device:
lp8788_iio_map_unregister(indio_dev, adc);
err_iio_map:
iio_device_free(indio_dev);
return ret;
}
static int lp8788_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct lp8788_adc *adc = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
lp8788_iio_map_unregister(indio_dev, adc);
iio_device_free(indio_dev);
return 0;
}
static struct platform_driver lp8788_adc_driver = {
.probe = lp8788_adc_probe,
.remove = lp8788_adc_remove,
.driver = {
.name = LP8788_DEV_ADC,
.owner = THIS_MODULE,
},
};
module_platform_driver(lp8788_adc_driver);
MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lp8788-adc");
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