Re: [PATCH v4 08/10] thermal: qcom: add support for adc-tm5 PMIC thermal monitor

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 10 Sep 2020 16:59:58 +0300
Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote:

> Add support for Thermal Monitoring part of PMIC5. This part is closely
> coupled with ADC, using it's channels directly. ADC-TM support
> generating interrupts on ADC value crossing low or high voltage bounds,
> which is used to support thermal trip points.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
A few trivial things inline.  Only one I'm really fussed about is
filling in the rest of the kernel-doc. I raised that in v2.

With that fixed,

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/iio/adc/qcom-vadc-common.c       |  62 +++
>  drivers/iio/adc/qcom-vadc-common.h       |   3 +
>  drivers/thermal/qcom/Kconfig             |  11 +
>  drivers/thermal/qcom/Makefile            |   1 +
>  drivers/thermal/qcom/qcom-spmi-adc-tm5.c | 568 +++++++++++++++++++++++
>  5 files changed, 645 insertions(+)
>  create mode 100644 drivers/thermal/qcom/qcom-spmi-adc-tm5.c
> 
> diff --git a/drivers/iio/adc/qcom-vadc-common.c b/drivers/iio/adc/qcom-vadc-common.c
> index 40d77b3af1bb..e58e393b8713 100644
> --- a/drivers/iio/adc/qcom-vadc-common.c
> +++ b/drivers/iio/adc/qcom-vadc-common.c
> @@ -377,6 +377,42 @@ static int qcom_vadc_map_voltage_temp(const struct vadc_map_pt *pts,
>  	return 0;
>  }
>  
> +static s32 qcom_vadc_map_temp_voltage(const struct vadc_map_pt *pts,
> +				      u32 tablesize, int input)
> +{
> +	bool descending = 1;
> +	u32 i = 0;
> +
> +	/* Check if table is descending or ascending */
> +	if (tablesize > 1) {
> +		if (pts[0].y < pts[1].y)
> +			descending = 0;
> +	}
> +
> +	while (i < tablesize) {
> +		if (descending && pts[i].y < input) {
> +			/* table entry is less than measured*/
> +			 /* value and table is descending, stop */
> +			break;
> +		} else if ((!descending) && pts[i].y > input) {
> +			/* table entry is greater than measured*/
> +			/*value and table is ascending, stop */
> +			break;
> +		}
> +		i++;
> +	}
> +
> +	if (i == 0)
> +		return pts[0].x;
> +	if (i == tablesize)
> +		return pts[tablesize - 1].x;
> +
> +	/* result is between search_index and search_index-1 */
> +	/* interpolate linearly */
> +	return fixp_linear_interpolate(pts[i - 1].y, pts[i - 1].x,
> +			pts[i].y, pts[i].x, input);
> +}
> +
>  static void qcom_vadc_scale_calib(const struct vadc_linear_graph *calib_graph,
>  				  u16 adc_code,
>  				  bool absolute,
> @@ -474,6 +510,19 @@ static int qcom_vadc_scale_chg_temp(const struct vadc_linear_graph *calib_graph,
>  	return 0;
>  }
>  
> +static u16 qcom_vadc_scale_voltage_code(int voltage,
> +					const struct vadc_prescale_ratio *prescale,
> +					const u32 full_scale_code_volt,
> +					unsigned int factor)
> +{
> +	s64 volt = voltage, adc_vdd_ref_mv = 1875;
> +
> +	volt *= prescale->num * factor * full_scale_code_volt;
> +	volt = div64_s64(volt, (s64)prescale->den * adc_vdd_ref_mv * 1000);
> +
> +	return volt;
> +}
> +
>  static int qcom_vadc_scale_code_voltage_factor(u16 adc_code,
>  				const struct vadc_prescale_ratio *prescale,
>  				const struct adc5_data *data,
> @@ -658,6 +707,19 @@ int qcom_vadc_scale(enum vadc_scale_fn_type scaletype,
>  }
>  EXPORT_SYMBOL(qcom_vadc_scale);
>  
> +u16 qcom_adc_tm5_temp_volt_scale(unsigned int prescale_ratio,
> +				 u32 full_scale_code_volt, int temp)
> +{
> +	const struct vadc_prescale_ratio *prescale = &adc5_prescale_ratios[prescale_ratio];
> +	s32 voltage;
> +
> +	voltage = qcom_vadc_map_temp_voltage(adcmap_100k_104ef_104fb_1875_vref,
> +					     ARRAY_SIZE(adcmap_100k_104ef_104fb_1875_vref),
> +					     temp);
> +	return qcom_vadc_scale_voltage_code(voltage, prescale, full_scale_code_volt, 1000);
> +}
> +EXPORT_SYMBOL(qcom_adc_tm5_temp_volt_scale);
> +
>  int qcom_adc5_hw_scale(enum vadc_scale_fn_type scaletype,
>  		    unsigned int prescale_ratio,
>  		    const struct adc5_data *data,
> diff --git a/drivers/iio/adc/qcom-vadc-common.h b/drivers/iio/adc/qcom-vadc-common.h
> index 7e5f6428e311..9af41201ad77 100644
> --- a/drivers/iio/adc/qcom-vadc-common.h
> +++ b/drivers/iio/adc/qcom-vadc-common.h
> @@ -172,6 +172,9 @@ int qcom_adc5_hw_scale(enum vadc_scale_fn_type scaletype,
>  		    const struct adc5_data *data,
>  		    u16 adc_code, int *result_mdec);
>  
> +u16 qcom_adc_tm5_temp_volt_scale(unsigned int prescale_ratio,
> +				 u32 full_scale_code_volt, int temp);
> +
>  int qcom_adc5_prescaling_from_dt(u32 num, u32 den);
>  
>  int qcom_adc5_hw_settle_time_from_dt(u32 value, const unsigned int *hw_settle);
> diff --git a/drivers/thermal/qcom/Kconfig b/drivers/thermal/qcom/Kconfig
> index aa9c1d80fae4..8d5ac2df26dc 100644
> --- a/drivers/thermal/qcom/Kconfig
> +++ b/drivers/thermal/qcom/Kconfig
> @@ -10,6 +10,17 @@ config QCOM_TSENS
>  	  Also able to set threshold temperature for both hot and cold and update
>  	  when a threshold is reached.
>  
> +config QCOM_SPMI_ADC_TM5
> +	tristate "Qualcomm SPMI PMIC Thermal Monitor ADC5"
> +	depends on OF && SPMI && IIO
> +	select REGMAP_SPMI
> +	select QCOM_VADC_COMMON
> +	help
> +	  This enables the thermal driver for the ADC thermal monitoring
> +	  device. It shows up as a thermal zone with multiple trip points.
> +	  Thermal client sets threshold temperature for both warm and cool and
> +	  gets updated when a threshold is reached.
> +
>  config QCOM_SPMI_TEMP_ALARM
>  	tristate "Qualcomm SPMI PMIC Temperature Alarm"
>  	depends on OF && SPMI && IIO
> diff --git a/drivers/thermal/qcom/Makefile b/drivers/thermal/qcom/Makefile
> index ec86eef7f6a6..252ea7d9da0b 100644
> --- a/drivers/thermal/qcom/Makefile
> +++ b/drivers/thermal/qcom/Makefile
> @@ -3,4 +3,5 @@ obj-$(CONFIG_QCOM_TSENS)	+= qcom_tsens.o
>  
>  qcom_tsens-y			+= tsens.o tsens-v2.o tsens-v1.o tsens-v0_1.o \
>  				   tsens-8960.o
> +obj-$(CONFIG_QCOM_SPMI_ADC_TM5)	+= qcom-spmi-adc-tm5.o
>  obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM)	+= qcom-spmi-temp-alarm.o
> diff --git a/drivers/thermal/qcom/qcom-spmi-adc-tm5.c b/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
> new file mode 100644
> index 000000000000..4a6e78e7b6ce
> --- /dev/null
> +++ b/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
> @@ -0,0 +1,568 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2020 Linaro Limited
> + */
> +
> +#include <linux/iio/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/thermal.h>
> +
> +#include "../../iio/adc/qcom-vadc-common.h"
> +
> +#define ADC5_MAX_CHANNEL                        0xc0
> +#define ADC_TM5_NUM_CHANNELS		8
> +
> +#define ADC_TM5_STATUS_LOW			0x0a
> +
> +#define ADC_TM5_STATUS_HIGH			0x0b
> +
> +#define ADC_TM5_NUM_BTM				0x0f
> +
> +#define ADC_TM5_ADC_DIG_PARAM			0x42
> +
> +#define ADC_TM5_FAST_AVG_CTL			(ADC_TM5_ADC_DIG_PARAM + 1)
> +#define ADC_TM5_FAST_AVG_EN				BIT(7)
> +
> +#define ADC_TM5_MEAS_INTERVAL_CTL		(ADC_TM5_ADC_DIG_PARAM + 2)
> +#define ADC_TM5_TIMER1					3 /* 3.9ms */
> +
> +#define ADC_TM5_MEAS_INTERVAL_CTL2		(ADC_TM5_ADC_DIG_PARAM + 3)
> +#define ADC_TM5_MEAS_INTERVAL_CTL2_MASK			0xf0
> +#define ADC_TM5_TIMER2					10 /* 1 second */
> +#define ADC_TM5_MEAS_INTERVAL_CTL3_MASK			0xf
> +#define ADC_TM5_TIMER3					4 /* 4 second */
> +
> +#define ADC_TM5_M_CHAN_BASE			0x60
> +
> +#define ADC_TM5_M_ADC_CH_SEL_CTL(n)		(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 0)
> +#define ADC_TM5_M_LOW_THR0(n)			(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 1)
> +#define ADC_TM5_M_LOW_THR1(n)			(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 2)
> +#define ADC_TM5_M_HIGH_THR0(n)			(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 3)
> +#define ADC_TM5_M_HIGH_THR1(n)			(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 4)
> +#define ADC_TM5_M_MEAS_INTERVAL_CTL(n)		(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 5)
> +#define ADC_TM5_M_CTL(n)			(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 6)
> +#define ADC_TM5_M_CTL_HW_SETTLE_DELAY_MASK		0xf
> +#define ADC_TM5_M_CTL_CAL_SEL_MASK			0x30
> +#define ADC_TM5_M_CTL_CAL_VAL				0x40
> +#define ADC_TM5_M_EN(n)				(ADC_TM5_M_CHAN_BASE + ((n) * 8) + 7)
> +#define ADC_TM5_M_MEAS_EN				BIT(7)
> +#define ADC_TM5_M_HIGH_THR_INT_EN			BIT(1)
> +#define ADC_TM5_M_LOW_THR_INT_EN			BIT(0)
> +
> +enum adc5_timer_select {
> +	ADC5_TIMER_SEL_1 = 0,
> +	ADC5_TIMER_SEL_2,
> +	ADC5_TIMER_SEL_3,
> +	ADC5_TIMER_SEL_NONE,
> +};
> +
> +struct adc_tm5_data {
> +	const u32	full_scale_code_volt;
> +	unsigned int	*decimation;
> +	unsigned int	*hw_settle;
> +};
> +
> +enum adc_tm5_cal_method {
> +	ADC_TM5_NO_CAL = 0,
> +	ADC_TM5_RATIOMETRIC_CAL,
> +	ADC_TM5_ABSOLUTE_CAL
> +};
> +
> +struct adc_tm5_chip;
> +
> +struct adc_tm5_channel {
> +	unsigned int		channel;
> +	unsigned int		adc_channel;
> +	enum adc_tm5_cal_method	cal_method;
> +	unsigned int		prescale;
> +	unsigned int		hw_settle_time;
> +	struct iio_channel	*iio;
> +	struct adc_tm5_chip	*chip;
> +	struct thermal_zone_device *tzd;
> +};
> +
> +/**
> + * struct adc_tm5_chip - ADC Thermal Monitoring properties

This is kernel-doc style, so unless you like warnings + the patches
that follow, document all the elements.

> + * @nchannels: amount of channels defined/allocated
> + * @decimation: sampling rate supported for the channel.
> + * @avg_samples: ability to provide single result from the ADC
> + *	that is an average of multiple measurements.
> + * @base: base address of TM registers.
> + */
> +struct adc_tm5_chip {
> +	struct regmap		*regmap;
> +	struct device		*dev;
> +	const struct adc_tm5_data	*data;
> +	struct adc_tm5_channel	*channels;
> +	unsigned int		nchannels;
> +	unsigned int		decimation;
> +	unsigned int		avg_samples;
> +	u16			base;
> +};
> +
> +static const struct adc_tm5_data adc_tm5_data_pmic = {
> +	.full_scale_code_volt = 0x70e4,
> +	.decimation = (unsigned int []) {250, 420, 840},
> +	.hw_settle = (unsigned int []) {15, 100, 200, 300, 400, 500, 600, 700,
> +					1, 2, 4, 8, 16, 32, 64, 128},
> +};
> +
> +static int adc_tm5_read(struct adc_tm5_chip *adc_tm, u16 offset, u8 *data, int len)
> +{
> +	return regmap_bulk_read(adc_tm->regmap, adc_tm->base + offset, data, len);
> +}
> +
> +static int adc_tm5_write(struct adc_tm5_chip *adc_tm, u16 offset, u8 *data, int len)
> +{
> +	return regmap_bulk_write(adc_tm->regmap, adc_tm->base + offset, data, len);
> +}
> +
> +static int adc_tm5_reg_update(struct adc_tm5_chip *adc_tm, u16 offset, u8 mask, u8 val)
> +{
> +	return regmap_write_bits(adc_tm->regmap, adc_tm->base + offset, mask, val);
> +}
> +
> +static irqreturn_t adc_tm5_isr(int irq, void *data)
> +{
> +	struct adc_tm5_chip *chip = data;
> +	u8 status_low, status_high, ctl;
> +	int ret = 0, i = 0;
> +
> +	ret = adc_tm5_read(chip, ADC_TM5_STATUS_LOW, &status_low, 1);
> +	if (ret) {
> +		dev_err(chip->dev, "read status low failed with %d\n", ret);
> +		return IRQ_HANDLED;
> +	}
> +
> +	ret = adc_tm5_read(chip, ADC_TM5_STATUS_HIGH, &status_high, 1);
> +	if (ret) {
> +		dev_err(chip->dev, "read status high failed with %d\n", ret);
> +		return IRQ_HANDLED;
> +	}
> +
> +	for (i = 0; i < chip->nchannels; i++) {
> +		bool upper_set = false, lower_set = false;
> +		unsigned int ch = chip->channels[i].channel;
> +
> +		if (!chip->channels[i].tzd) {
> +			dev_err_once(chip->dev, "thermal device not found\n");
> +			continue;
> +		}
> +
> +		ret = adc_tm5_read(chip, ADC_TM5_M_EN(ch), &ctl, 1);
> +
> +		if (ret) {
> +			dev_err(chip->dev, "ctl read failed with %d\n", ret);
> +			continue;
> +		}
> +
> +		lower_set = (status_low & BIT(ch)) &&
> +			(ctl & ADC_TM5_M_MEAS_EN) &&
> +			(ctl & ADC_TM5_M_LOW_THR_INT_EN);
> +
> +		upper_set = (status_high & BIT(ch)) &&
> +			(ctl & ADC_TM5_M_MEAS_EN) &&
> +			(ctl & ADC_TM5_M_HIGH_THR_INT_EN);
> +
> +		if (upper_set || lower_set)
> +			thermal_zone_device_update(chip->channels[i].tzd,
> +						   THERMAL_EVENT_UNSPECIFIED);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int adc_tm5_get_temp(void *data, int *temp)
> +{
> +	struct adc_tm5_channel *channel = data;
> +	int ret, milli_celsius;
> +
> +	if (!channel || !channel->iio)
> +		return -EINVAL;
> +
> +	ret = iio_read_channel_processed(channel->iio, &milli_celsius);
> +	if (ret < 0)
> +		return ret;
> +
> +	*temp = milli_celsius;
> +
> +	return 0;
> +}
> +
> +static int adc_tm5_disable_channel(struct adc_tm5_channel *channel)
> +{
> +	struct adc_tm5_chip *chip = channel->chip;
> +	unsigned int reg = ADC_TM5_M_EN(channel->channel);
> +
> +	return adc_tm5_reg_update(chip, reg,
> +			ADC_TM5_M_MEAS_EN | ADC_TM5_M_HIGH_THR_INT_EN | ADC_TM5_M_LOW_THR_INT_EN,
> +			0);
> +}
> +
> +static int adc_tm5_configure(struct adc_tm5_channel *channel, int low_temp, int high_temp)
> +{
> +	struct adc_tm5_chip *chip = channel->chip;
> +	u8 buf[8];
> +	u16 reg = ADC_TM5_M_ADC_CH_SEL_CTL(channel->channel);
> +	int ret = 0;
> +
> +	ret = adc_tm5_read(chip, reg, buf, 8);

As below, slight preference for sizeof(buf)

> +	if (ret) {
> +		dev_err(chip->dev, "block read failed with %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Update ADC channel select */
> +	buf[0] = channel->adc_channel;
> +
> +	/* Warm temperature corresponds to low voltage threshold */
> +	if (high_temp != INT_MAX) {
> +		u16 adc_code = qcom_adc_tm5_temp_volt_scale(channel->prescale,
> +				chip->data->full_scale_code_volt, high_temp);
> +
> +		buf[1] = adc_code & 0xff;
> +		buf[2] = adc_code >> 8;
> +		buf[7] |= ADC_TM5_M_LOW_THR_INT_EN;
> +	}
> +
> +	/* Cool temperature corresponds to high voltage threshold */
> +	if (low_temp != -INT_MAX) {
> +		u16 adc_code = qcom_adc_tm5_temp_volt_scale(channel->prescale,
> +				chip->data->full_scale_code_volt, low_temp);
> +
> +		buf[3] = adc_code & 0xff;
> +		buf[4] = adc_code >> 8;
> +		buf[7] |= ADC_TM5_M_HIGH_THR_INT_EN;
> +	}
> +
> +	/* Update timer select */
> +	buf[5] = ADC5_TIMER_SEL_2;
> +
> +	/* Set calibration select, hw_settle delay */
> +	buf[6] &= ~ADC_TM5_M_CTL_HW_SETTLE_DELAY_MASK;
> +	buf[6] |= FIELD_PREP(ADC_TM5_M_CTL_HW_SETTLE_DELAY_MASK, channel->hw_settle_time);
> +	buf[6] &= ~ADC_TM5_M_CTL_CAL_SEL_MASK;
> +	buf[6] |= FIELD_PREP(ADC_TM5_M_CTL_CAL_SEL_MASK, channel->cal_method);
> +
> +	buf[7] |= ADC_TM5_M_MEAS_EN;
> +
> +	ret = adc_tm5_write(chip, reg, buf, 8);
> +	if (ret)
> +		dev_err(chip->dev, "buf write failed\n");
> +
> +	return ret;
> +}
> +
> +static int adc_tm5_set_trips(void *data, int low_temp, int high_temp)
> +{
> +	struct adc_tm5_channel *channel = data;
> +	struct adc_tm5_chip *chip;
> +	int ret;
> +
> +	if (!channel)
> +		return -EINVAL;
> +
> +	chip = channel->chip;
> +	dev_dbg(chip->dev, "%d:low_temp(mdegC):%d, high_temp(mdegC):%d\n",
> +		channel->channel, low_temp, high_temp);
> +
> +	if (high_temp == INT_MAX && low_temp <= -INT_MAX)
> +		ret = adc_tm5_disable_channel(channel);
> +	else
> +		ret = adc_tm5_configure(channel, low_temp, high_temp);
> +
> +	return ret;
> +}
> +
> +static struct thermal_zone_of_device_ops adc_tm5_ops = {
> +	.get_temp = adc_tm5_get_temp,
> +	.set_trips = adc_tm5_set_trips,
> +};
> +
> +static int adc_tm5_register_tzd(struct adc_tm5_chip *adc_tm)
> +{
> +	unsigned int i;
> +	struct thermal_zone_device *tzd;
> +
> +	for (i = 0; i < adc_tm->nchannels; i++) {
> +		adc_tm->channels[i].chip = adc_tm;
> +
> +		tzd = devm_thermal_zone_of_sensor_register(adc_tm->dev,
> +							   adc_tm->channels[i].channel,
> +							   &adc_tm->channels[i],
> +							   &adc_tm5_ops);
> +		if (IS_ERR(tzd)) {
> +			dev_err(adc_tm->dev, "Error registering TZ zone:%ld for channel:%d\n",
> +				PTR_ERR(tzd), adc_tm->channels[i].channel);
> +			continue;
> +		}
> +		adc_tm->channels[i].tzd = tzd;
> +	}
> +
> +	return 0;
> +}
> +
> +static int adc_tm5_init(struct adc_tm5_chip *chip)
> +{
> +	u8 buf[4], channels_available;
> +	int ret;
> +	unsigned int i;
> +
> +	ret = adc_tm5_read(chip, ADC_TM5_NUM_BTM, &channels_available, 1);
> +	if (ret) {
> +		dev_err(chip->dev, "read failed for BTM channels\n");
> +		return ret;
> +	}
> +
> +	ret = adc_tm5_read(chip, ADC_TM5_ADC_DIG_PARAM, buf, 4);

Ever so slight preference for using sizeof(buf).


> +	if (ret) {
> +		dev_err(chip->dev, "block read failed with %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Select decimation */
> +	buf[0] = chip->decimation;
> +
> +	/* Select number of samples in fast average mode */
> +	buf[1] = chip->avg_samples | ADC_TM5_FAST_AVG_EN;
> +
> +	/* Select timer1 */
> +	buf[2] = ADC_TM5_TIMER1;
> +
> +	/* Select timer2 and timer3 */
> +	buf[3] = FIELD_PREP(ADC_TM5_MEAS_INTERVAL_CTL2_MASK, ADC_TM5_TIMER2) |
> +		 FIELD_PREP(ADC_TM5_MEAS_INTERVAL_CTL3_MASK, ADC_TM5_TIMER3);
> +
> +	ret = adc_tm5_write(chip, ADC_TM5_ADC_DIG_PARAM, buf, 4);
> +	if (ret)
> +		dev_err(chip->dev, "block write failed with %d\n", ret);
> +
> +	for (i = 0; i < chip->nchannels; i++) {
> +		if (chip->channels[i].channel >= channels_available) {
> +			dev_err(chip->dev, "Invalid channel %d\n", chip->channels[i].channel);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int adc_tm5_get_dt_channel_data(struct adc_tm5_chip *adc_tm,
> +				       struct adc_tm5_channel *channel,
> +				       struct device_node *node)
> +{
> +	const char *name = node->name;
> +	u32 chan, value, varr[2];
> +	int ret;
> +	struct device *dev = adc_tm->dev;
> +
> +	ret = of_property_read_u32(node, "reg", &chan);
> +	if (ret) {
> +		dev_err(dev, "invalid channel number %s\n", name);
> +		return ret;
> +	}
> +
> +	if (chan >= ADC_TM5_NUM_CHANNELS) {
> +		dev_err(dev, "%s invalid channel number %d\n", name, chan);
> +		return -EINVAL;
> +	}
> +
> +	/* the channel has DT description */
> +	channel->channel = chan;
> +
> +	ret = of_property_read_u32(node, "qcom,adc-channel", &chan);
> +	if (ret) {
> +		dev_err(dev, "invalid channel number %s\n", name);
> +		return ret;
> +	}
> +	if (chan >= ADC5_MAX_CHANNEL) {
> +		dev_err(dev, "%s invalid ADC channel number %d\n", name, chan);
> +		return ret;
> +	}
> +	channel->adc_channel = chan;
> +
> +	channel->iio = devm_of_iio_channel_get_by_name(adc_tm->dev, node, NULL);
> +	if (IS_ERR(channel->iio)) {
> +		ret = PTR_ERR(channel->iio);
> +		channel->iio = NULL;
> +		if (ret != -EPROBE_DEFER)
> +			dev_err(dev, "error getting channel %s: %d\n", name, ret);
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
> +	if (!ret) {
> +		ret = qcom_adc5_prescaling_from_dt(varr[0], varr[1]);
> +		if (ret < 0) {
> +			dev_err(dev, "%02x invalid pre-scaling <%d %d>\n",
> +				chan, varr[0], varr[1]);
> +			return ret;
> +		}
> +		channel->prescale = ret;
> +	} else {
> +		/* 1:1 prescale is index 0 */
> +		channel->prescale = 0;
> +	}
> +
> +	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
> +	if (!ret) {
> +		ret = qcom_adc5_hw_settle_time_from_dt(value, adc_tm->data->hw_settle);
> +		if (ret < 0) {
> +			dev_err(dev, "%02x invalid hw-settle-time %d us\n",
> +				chan, value);
> +			return ret;
> +		}
> +		channel->hw_settle_time = ret;
> +	} else {
> +		channel->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
> +	}
> +
> +	if (of_property_read_bool(node, "qcom,ratiometric"))
> +		channel->cal_method = ADC_TM5_RATIOMETRIC_CAL;
> +	else
> +		channel->cal_method = ADC_TM5_ABSOLUTE_CAL;
> +
> +	return 0;
> +}
> +
> +static int adc_tm5_get_dt_data(struct adc_tm5_chip *adc_tm, struct device_node *node)
> +{
> +	struct adc_tm5_channel *channels;
> +	struct device_node *child;
> +	unsigned int index = 0;
> +	u32 value;
> +	int ret;
> +	struct device *dev = adc_tm->dev;
> +
> +	adc_tm->nchannels = of_get_available_child_count(node);
> +	if (!adc_tm->nchannels)
> +		return -EINVAL;
> +
> +	adc_tm->channels = devm_kcalloc(dev, adc_tm->nchannels,
> +					sizeof(*adc_tm->channels), GFP_KERNEL);
> +	if (!adc_tm->channels)
> +		return -ENOMEM;
> +
> +	channels = adc_tm->channels;
> +
> +	adc_tm->data = of_device_get_match_data(dev);
> +	if (!adc_tm->data)
> +		adc_tm->data = &adc_tm5_data_pmic;
> +
> +	ret = of_property_read_u32(node, "qcom,decimation", &value);
> +	if (!ret) {
> +		ret = qcom_adc5_decimation_from_dt(value, adc_tm->data->decimation);
> +		if (ret < 0) {
> +			dev_err(dev, "invalid decimation %d\n", value);
> +			return ret;
> +		}
> +		adc_tm->decimation = ret;
> +	} else {
> +		adc_tm->decimation = ADC5_DECIMATION_DEFAULT;
> +	}
> +
> +	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
> +	if (!ret) {
> +		ret = qcom_adc5_avg_samples_from_dt(value);
> +		if (ret < 0) {
> +			dev_err(dev, "invalid avg-samples %d\n", value);
> +			return ret;
> +		}
> +		adc_tm->avg_samples = ret;
> +	} else {
> +		adc_tm->avg_samples = VADC_DEF_AVG_SAMPLES;
> +	}
> +
> +	for_each_available_child_of_node(node, child) {
> +		ret = adc_tm5_get_dt_channel_data(adc_tm, channels, child);
> +		if (ret) {
> +			of_node_put(child);
> +			return ret;
> +		}
> +
> +		channels++;
> +		index++;
> +	}
> +
> +	return 0;
> +}
> +
> +static int adc_tm5_probe(struct platform_device *pdev)
> +{
> +	struct device_node *node = pdev->dev.of_node;
> +	struct device *dev = &pdev->dev;
> +	struct adc_tm5_chip *adc_tm;
> +	struct regmap *regmap;
> +	int ret, irq;
> +	u32 reg;
> +
> +	regmap = dev_get_regmap(dev->parent, NULL);
> +	if (!regmap)
> +		return -ENODEV;
> +
> +	ret = of_property_read_u32(node, "reg", &reg);
> +	if (ret)
> +		return ret;
> +
> +	adc_tm = devm_kzalloc(&pdev->dev, sizeof(*adc_tm), GFP_KERNEL);
> +	if (!adc_tm)
> +		return -ENOMEM;
> +
> +	adc_tm->regmap = regmap;
> +	adc_tm->dev = dev;
> +	adc_tm->base = reg;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(dev, "get_irq failed: %d\n", irq);
> +		return irq;
> +	}
> +
> +	ret = adc_tm5_get_dt_data(adc_tm, node);
> +	if (ret) {
> +		dev_err(dev, "get dt data failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = adc_tm5_init(adc_tm);
> +	if (ret) {
> +		dev_err(dev, "adc-tm init failed\n");
> +		return ret;
> +	}
> +
> +	ret = adc_tm5_register_tzd(adc_tm);
> +	if (ret) {
> +		dev_err(dev, "tzd register failed\n");
> +		return ret;
> +	}
> +
> +	return devm_request_irq(dev, irq, adc_tm5_isr, 0,
> +			       "pm-adc-tm5", adc_tm);

Nitpick: That looks like it fits on one line under 80 chars.

> +}
> +
> +static const struct of_device_id adc_tm5_match_table[] = {
> +	{
> +		.compatible = "qcom,spmi-adc-tm5",
> +		.data = &adc_tm5_data_pmic,
> +	},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, adc_tm5_match_table);
> +
> +static struct platform_driver adc_tm5_driver = {
> +	.driver = {
> +		.name = "qcom-spmi-adc-tm5",
> +		.of_match_table = adc_tm5_match_table,
> +	},
> +	.probe = adc_tm5_probe,
> +};
> +module_platform_driver(adc_tm5_driver);
> +
> +MODULE_DESCRIPTION("SPMI PMIC Thermal Monitor ADC driver");
> +MODULE_LICENSE("GPL v2");