Re: [PATCH v3 08/10] thermal: qcom: add support for adc-tm5 PMIC thermal monitor

Jonathan Cameron
2020-09-09T18:18:30Z

On Wed, 9 Sep 2020 17:42:46 +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>

There's some noisy white space changes in here that I'd rather like
cleared out. Otherwise look good to me.
The coupling between the two drivers is tighter than ideal,
but I guess there is no other way of handling them as the
two parts don't separate well.

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

> ---
> drivers/iio/adc/qcom-vadc-common.c | 74 ++-
> 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 | 567 +++++++++++++++++++++++
> 5 files changed, 650 insertions(+), 6 deletions(-)
> 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..fbdf501954ed 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,
> @@ -474,10 +510,23 @@ 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,
> - unsigned int factor)
> + const struct vadc_prescale_ratio *prescale,
> + const struct adc5_data *data,
> + unsigned int factor)
> {
> s64 voltage, temp, adc_vdd_ref_mv = 1875;
>
> @@ -658,10 +707,23 @@ 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,
> - u16 adc_code, int *result)
> + unsigned int prescale_ratio,
> + const struct adc5_data *data,
> + u16 adc_code, int *result)

Clean that change out. I have no particular problem with white space
tidying up, but not in a patch that makes functional changes. I just
end up staring at them on the assumption something must have changed!

> {
> const struct vadc_prescale_ratio *prescale = &adc5_prescale_ratios[prescale_ratio];
>
> 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..82eda6e011ab
> --- /dev/null
> +++ b/drivers/thermal/qcom/qcom-spmi-adc-tm5.c
> @@ -0,0 +1,567 @@
> +// 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
> + * @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);
> + 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);
> + 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);

Is there any potential that we have a deferred response here?

> + channel->iio = NULL;
> + 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);
> +}
> +
> +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");