/*
* axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
*
* Copyright (C) 2014 Intel Corporation
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/mfd/axp20x.h>
#include <linux/platform_device.h>
#include <linux/iio/iio.h>
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
/*
* This mask enables all ADCs except for the battery temp-sensor (TS), that is
* left as-is to avoid breaking charging on devices without a temp-sensor.
*/
#define AXP288_ADC_EN_MASK 0xF0
#define AXP288_ADC_TS_ENABLE 0x01
#define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0)
#define AXP288_ADC_TS_CURRENT_OFF (0 << 0)
#define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0)
#define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0)
#define AXP288_ADC_TS_CURRENT_ON (3 << 0)
enum axp288_adc_id {
AXP288_ADC_TS,
AXP288_ADC_PMIC,
AXP288_ADC_GP,
AXP288_ADC_BATT_CHRG_I,
AXP288_ADC_BATT_DISCHRG_I,
AXP288_ADC_BATT_V,
AXP288_ADC_NR_CHAN,
};
struct axp288_adc_info {
int irq;
struct regmap *regmap;
bool ts_enabled;
};
static const struct iio_chan_spec axp288_adc_channels[] = {
{
.indexed = 1,
.type = IIO_TEMP,
.channel = 0,
.address = AXP288_TS_ADC_H,
.datasheet_name = "TS_PIN",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.indexed = 1,
.type = IIO_TEMP,
.channel = 1,
.address = AXP288_PMIC_ADC_H,
.datasheet_name = "PMIC_TEMP",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.indexed = 1,
.type = IIO_TEMP,
.channel = 2,
.address = AXP288_GP_ADC_H,
.datasheet_name = "GPADC",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.indexed = 1,
.type = IIO_CURRENT,
.channel = 3,
.address = AXP20X_BATT_CHRG_I_H,
.datasheet_name = "BATT_CHG_I",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.indexed = 1,
.type = IIO_CURRENT,
.channel = 4,
.address = AXP20X_BATT_DISCHRG_I_H,
.datasheet_name = "BATT_DISCHRG_I",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.indexed = 1,
.type = IIO_VOLTAGE,
.channel = 5,
.address = AXP20X_BATT_V_H,
.datasheet_name = "BATT_V",
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
},
};
/* for consumer drivers */
static struct iio_map axp288_adc_default_maps[] = {
IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
{},
};
static int axp288_adc_read_channel(int *val, unsigned long address,
struct regmap *regmap)
{
u8 buf[2];
if (regmap_bulk_read(regmap, address, buf, 2))
return -EIO;
*val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
return IIO_VAL_INT;
}
/*
* The current-source used for the battery temp-sensor (TS) is shared
* with the GPADC. For proper fuel-gauge and charger operation the TS
* current-source needs to be permanently on. But to read the GPADC we
* need to temporary switch the TS current-source to ondemand, so that
* the GPADC can use it, otherwise we will always read an all 0 value.
*/
static int axp288_adc_set_ts(struct axp288_adc_info *info,
unsigned int mode, unsigned long address)
{
int ret;
/* No need to switch the current-source if the TS pin is disabled */
if (!info->ts_enabled)
return 0;
/* Channels other than GPADC do not need the current source */
if (address != AXP288_GP_ADC_H)
return 0;
ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
if (ret)
return ret;
/* When switching to the GPADC pin give things some time to settle */
if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
usleep_range(6000, 10000);
return 0;
}
static int axp288_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret;
struct axp288_adc_info *info = iio_priv(indio_dev);
mutex_lock(&indio_dev->mlock);
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
chan->address)) {
dev_err(&indio_dev->dev, "GPADC mode\n");
ret = -EINVAL;
break;
}
ret = axp288_adc_read_channel(val, chan->address, info->regmap);
if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
chan->address))
dev_err(&indio_dev->dev, "TS pin restore\n");
break;
default:
ret = -EINVAL;
}
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int axp288_adc_initialize(struct axp288_adc_info *info)
{
int ret, adc_enable_val;
/*
* Determine if the TS pin is enabled and set the TS current-source
* accordingly.
*/
ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
if (ret)
return ret;
if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
info->ts_enabled = true;
ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
AXP288_ADC_TS_CURRENT_ON);
} else {
info->ts_enabled = false;
ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
AXP288_ADC_TS_CURRENT_OFF);
}
if (ret)
return ret;
/* Turn on the ADC for all channels except TS, leave TS as is */
return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
}
static const struct iio_info axp288_adc_iio_info = {
.read_raw = &axp288_adc_read_raw,
};
static int axp288_adc_probe(struct platform_device *pdev)
{
int ret;
struct axp288_adc_info *info;
struct iio_dev *indio_dev;
struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
if (!indio_dev)
return -ENOMEM;
info = iio_priv(indio_dev);
info->irq = platform_get_irq(pdev, 0);
if (info->irq < 0) {
dev_err(&pdev->dev, "no irq resource?\n");
return info->irq;
}
platform_set_drvdata(pdev, indio_dev);
info->regmap = axp20x->regmap;
/*
* Set ADC to enabled state at all time, including system suspend.
* otherwise internal fuel gauge functionality may be affected.
*/
ret = axp288_adc_initialize(info);
if (ret) {
dev_err(&pdev->dev, "unable to enable ADC device\n");
return ret;
}
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = pdev->name;
indio_dev->channels = axp288_adc_channels;
indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
indio_dev->info = &axp288_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = iio_map_array_register(indio_dev, axp288_adc_default_maps);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&pdev->dev, "unable to register iio device\n");
goto err_array_unregister;
}
return 0;
err_array_unregister:
iio_map_array_unregister(indio_dev);
return ret;
}
static int axp288_adc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
iio_device_unregister(indio_dev);
iio_map_array_unregister(indio_dev);
return 0;
}
static const struct platform_device_id axp288_adc_id_table[] = {
{ .name = "axp288_adc" },
{},
};
static struct platform_driver axp288_adc_driver = {
.probe = axp288_adc_probe,
.remove = axp288_adc_remove,
.id_table = axp288_adc_id_table,
.driver = {
.name = "axp288_adc",
},
};
MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
module_platform_driver(axp288_adc_driver);
MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
MODULE_LICENSE("GPL");
