315 lines
		
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			315 lines
		
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver
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|  *
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|  * Copyright (C) 2014 Intel Corporation
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|  *
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|  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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|  */
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| 
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| #include <linux/dmi.h>
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| #include <linux/module.h>
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| #include <linux/kernel.h>
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| #include <linux/device.h>
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| #include <linux/regmap.h>
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| #include <linux/mfd/axp20x.h>
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| #include <linux/platform_device.h>
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| 
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| #include <linux/iio/iio.h>
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| #include <linux/iio/machine.h>
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| #include <linux/iio/driver.h>
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| 
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| /*
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|  * This mask enables all ADCs except for the battery temp-sensor (TS), that is
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|  * left as-is to avoid breaking charging on devices without a temp-sensor.
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|  */
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| #define AXP288_ADC_EN_MASK				0xF0
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| #define AXP288_ADC_TS_ENABLE				0x01
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| 
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| #define AXP288_ADC_TS_BIAS_MASK				GENMASK(5, 4)
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| #define AXP288_ADC_TS_BIAS_20UA				(0 << 4)
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| #define AXP288_ADC_TS_BIAS_40UA				(1 << 4)
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| #define AXP288_ADC_TS_BIAS_60UA				(2 << 4)
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| #define AXP288_ADC_TS_BIAS_80UA				(3 << 4)
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| #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK		GENMASK(1, 0)
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| #define AXP288_ADC_TS_CURRENT_OFF			(0 << 0)
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| #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING		(1 << 0)
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| #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND		(2 << 0)
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| #define AXP288_ADC_TS_CURRENT_ON			(3 << 0)
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| 
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| enum axp288_adc_id {
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| 	AXP288_ADC_TS,
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| 	AXP288_ADC_PMIC,
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| 	AXP288_ADC_GP,
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| 	AXP288_ADC_BATT_CHRG_I,
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| 	AXP288_ADC_BATT_DISCHRG_I,
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| 	AXP288_ADC_BATT_V,
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| 	AXP288_ADC_NR_CHAN,
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| };
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| 
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| struct axp288_adc_info {
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| 	int irq;
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| 	struct regmap *regmap;
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| 	bool ts_enabled;
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| };
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| 
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| static const struct iio_chan_spec axp288_adc_channels[] = {
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| 	{
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| 		.indexed = 1,
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| 		.type = IIO_TEMP,
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| 		.channel = 0,
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| 		.address = AXP288_TS_ADC_H,
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| 		.datasheet_name = "TS_PIN",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	}, {
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| 		.indexed = 1,
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| 		.type = IIO_TEMP,
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| 		.channel = 1,
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| 		.address = AXP288_PMIC_ADC_H,
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| 		.datasheet_name = "PMIC_TEMP",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	}, {
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| 		.indexed = 1,
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| 		.type = IIO_TEMP,
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| 		.channel = 2,
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| 		.address = AXP288_GP_ADC_H,
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| 		.datasheet_name = "GPADC",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	}, {
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| 		.indexed = 1,
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| 		.type = IIO_CURRENT,
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| 		.channel = 3,
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| 		.address = AXP20X_BATT_CHRG_I_H,
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| 		.datasheet_name = "BATT_CHG_I",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	}, {
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| 		.indexed = 1,
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| 		.type = IIO_CURRENT,
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| 		.channel = 4,
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| 		.address = AXP20X_BATT_DISCHRG_I_H,
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| 		.datasheet_name = "BATT_DISCHRG_I",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	}, {
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| 		.indexed = 1,
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| 		.type = IIO_VOLTAGE,
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| 		.channel = 5,
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| 		.address = AXP20X_BATT_V_H,
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| 		.datasheet_name = "BATT_V",
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| 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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| 	},
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| };
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| 
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| /* for consumer drivers */
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| static struct iio_map axp288_adc_default_maps[] = {
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| 	IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
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| 	IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
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| 	IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
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| 	IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
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| 	IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
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| 	IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
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| 	{},
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| };
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| 
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| static int axp288_adc_read_channel(int *val, unsigned long address,
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| 				struct regmap *regmap)
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| {
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| 	u8 buf[2];
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| 
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| 	if (regmap_bulk_read(regmap, address, buf, 2))
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| 		return -EIO;
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| 	*val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F);
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| 
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| 	return IIO_VAL_INT;
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| }
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| 
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| /*
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|  * The current-source used for the battery temp-sensor (TS) is shared
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|  * with the GPADC. For proper fuel-gauge and charger operation the TS
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|  * current-source needs to be permanently on. But to read the GPADC we
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|  * need to temporary switch the TS current-source to ondemand, so that
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|  * the GPADC can use it, otherwise we will always read an all 0 value.
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|  */
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| static int axp288_adc_set_ts(struct axp288_adc_info *info,
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| 			     unsigned int mode, unsigned long address)
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| {
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| 	int ret;
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| 
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| 	/* No need to switch the current-source if the TS pin is disabled */
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| 	if (!info->ts_enabled)
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| 		return 0;
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| 
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| 	/* Channels other than GPADC do not need the current source */
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| 	if (address != AXP288_GP_ADC_H)
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| 		return 0;
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| 
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| 	ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
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| 				 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode);
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| 	if (ret)
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| 		return ret;
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| 
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| 	/* When switching to the GPADC pin give things some time to settle */
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| 	if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND)
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| 		usleep_range(6000, 10000);
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| 
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| 	return 0;
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| }
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| 
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| static int axp288_adc_read_raw(struct iio_dev *indio_dev,
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| 			struct iio_chan_spec const *chan,
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| 			int *val, int *val2, long mask)
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| {
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| 	int ret;
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| 	struct axp288_adc_info *info = iio_priv(indio_dev);
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| 
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| 	mutex_lock(&indio_dev->mlock);
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| 	switch (mask) {
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| 	case IIO_CHAN_INFO_RAW:
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| 		if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
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| 					chan->address)) {
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| 			dev_err(&indio_dev->dev, "GPADC mode\n");
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| 			ret = -EINVAL;
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| 			break;
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| 		}
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| 		ret = axp288_adc_read_channel(val, chan->address, info->regmap);
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| 		if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON,
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| 						chan->address))
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| 			dev_err(&indio_dev->dev, "TS pin restore\n");
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| 		break;
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| 	default:
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| 		ret = -EINVAL;
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| 	}
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| 	mutex_unlock(&indio_dev->mlock);
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| 
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| 	return ret;
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| }
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| 
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| /*
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|  * We rely on the machine's firmware to correctly setup the TS pin bias current
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|  * at boot. This lists systems with broken fw where we need to set it ourselves.
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|  */
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| static const struct dmi_system_id axp288_adc_ts_bias_override[] = {
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| 	{
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| 		/* Lenovo Ideapad 100S (11 inch) */
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| 		.matches = {
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| 		  DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
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| 		  DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"),
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| 		},
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| 		.driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
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| 	},
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| 	{
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| 		/* Nuvision Solo 10 Draw */
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| 		.matches = {
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| 		  DMI_MATCH(DMI_SYS_VENDOR, "TMAX"),
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| 		  DMI_MATCH(DMI_PRODUCT_NAME, "TM101W610L"),
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| 		},
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| 		.driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA,
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| 	},
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| 	{}
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| };
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| 
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| static int axp288_adc_initialize(struct axp288_adc_info *info)
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| {
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| 	const struct dmi_system_id *bias_override;
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| 	int ret, adc_enable_val;
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| 
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| 	bias_override = dmi_first_match(axp288_adc_ts_bias_override);
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| 	if (bias_override) {
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| 		ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
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| 					 AXP288_ADC_TS_BIAS_MASK,
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| 					 (uintptr_t)bias_override->driver_data);
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| 		if (ret)
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| 			return ret;
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| 	}
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| 
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| 	/*
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| 	 * Determine if the TS pin is enabled and set the TS current-source
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| 	 * accordingly.
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| 	 */
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| 	ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val);
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| 	if (ret)
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| 		return ret;
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| 
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| 	if (adc_enable_val & AXP288_ADC_TS_ENABLE) {
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| 		info->ts_enabled = true;
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| 		ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
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| 					 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
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| 					 AXP288_ADC_TS_CURRENT_ON);
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| 	} else {
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| 		info->ts_enabled = false;
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| 		ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL,
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| 					 AXP288_ADC_TS_CURRENT_ON_OFF_MASK,
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| 					 AXP288_ADC_TS_CURRENT_OFF);
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| 	}
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| 	if (ret)
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| 		return ret;
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| 
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| 	/* Turn on the ADC for all channels except TS, leave TS as is */
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| 	return regmap_update_bits(info->regmap, AXP20X_ADC_EN1,
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| 				  AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK);
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| }
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| 
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| static const struct iio_info axp288_adc_iio_info = {
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| 	.read_raw = &axp288_adc_read_raw,
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| };
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| 
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| static int axp288_adc_probe(struct platform_device *pdev)
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| {
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| 	int ret;
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| 	struct axp288_adc_info *info;
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| 	struct iio_dev *indio_dev;
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| 	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
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| 
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| 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
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| 	if (!indio_dev)
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| 		return -ENOMEM;
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| 
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| 	info = iio_priv(indio_dev);
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| 	info->irq = platform_get_irq(pdev, 0);
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| 	if (info->irq < 0)
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| 		return info->irq;
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| 
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| 	info->regmap = axp20x->regmap;
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| 	/*
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| 	 * Set ADC to enabled state at all time, including system suspend.
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| 	 * otherwise internal fuel gauge functionality may be affected.
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| 	 */
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| 	ret = axp288_adc_initialize(info);
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| 	if (ret) {
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| 		dev_err(&pdev->dev, "unable to enable ADC device\n");
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| 		return ret;
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| 	}
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| 
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| 	indio_dev->name = pdev->name;
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| 	indio_dev->channels = axp288_adc_channels;
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| 	indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels);
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| 	indio_dev->info = &axp288_adc_iio_info;
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| 	indio_dev->modes = INDIO_DIRECT_MODE;
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| 
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| 	ret = devm_iio_map_array_register(&pdev->dev, indio_dev, axp288_adc_default_maps);
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| 	if (ret < 0)
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| 		return ret;
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| 
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| 	return devm_iio_device_register(&pdev->dev, indio_dev);
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| }
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| 
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| static const struct platform_device_id axp288_adc_id_table[] = {
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| 	{ .name = "axp288_adc" },
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| 	{},
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| };
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| 
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| static struct platform_driver axp288_adc_driver = {
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| 	.probe = axp288_adc_probe,
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| 	.id_table = axp288_adc_id_table,
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| 	.driver = {
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| 		.name = "axp288_adc",
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| 	},
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| };
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| 
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| MODULE_DEVICE_TABLE(platform, axp288_adc_id_table);
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| 
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| module_platform_driver(axp288_adc_driver);
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| 
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| MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>");
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| MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver");
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| MODULE_LICENSE("GPL");
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