Re: [PATCH v9 3/3] iio: adc: add support for Allwinner SoCs ADC
From: Jonathan Cameron
Date: Fri Dec 30 2016 - 09:40:57 EST
On 13/12/16 14:33, Quentin Schulz wrote:
> The Allwinner SoCs all have an ADC that can also act as a touchscreen
> controller and a thermal sensor. This patch adds the ADC driver which is
> based on the MFD for the same SoCs ADC.
>
> This also registers the thermal adc channel in the iio map array so
> iio_hwmon could use it without modifying the Device Tree. This registers
> the driver in the thermal framework.
>
> The thermal sensor requires the IP to be in touchscreen mode to return
> correct values. Therefore, if the user is continuously reading the ADC
> channel(s), the thermal framework in which the thermal sensor is
> registered will switch the IP in touchscreen mode to get a temperature
> value and requires a delay of 100ms (because of the mode switching),
> then the ADC will switch back to ADC mode and requires also a delay of
> 100ms. If the ADC readings are critical to user and the SoC temperature
> is not, this driver is capable of not registering the thermal sensor in
> the thermal framework and thus, "quicken" the ADC readings.
>
> This driver probes on three different platform_device_id to take into
> account slight differences (registers bit and temperature computation)
> between Allwinner SoCs ADCs.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
> Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
> Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>
One comment inline but not a blocker.
I would ideally like an ack from the thermal side. The relevant code
is small, but best to be sure and keep them in the loop as well.
It does feel a little convoluted to have both this directly providing
a thermal zone and being able to create one indirectly through hwmon as
well but this solution works for me I think...
Cc'd Zang and Eduardo.
Jonathan
> ---
>
> v9:
> - clarify comment on why we have to use the parent node as node for
> registering in thermal framework, (backward compatibility)
> - clarify comment on why we can disable CONFIG_THERMAL_OF,
> - clarify Kconfig help to say that CONFIG_THERMAL_OF can be disabled
> but should not in most cases,
> - make return value of devm_thermal_zone_of_sensor_register a local
> variable of the condition block,
> - correct scale from _PLUS_MICRO to _PLUS_NANO for ADC raw readings
> scale,
>
> v8:
> - remove Kconfig depends on !TOUCHSCREEN_SUN4I (moved to
> MFD_SUN4I_GPADC),
> - fix return values of regmap_irq_get_virq and platform_get_irq_byname
> stored in an unsigned int and then check if negative,
> - fix uninitialized ret value when an error occurs while registering
> the thermal sensor in the framework,
>
> v7:
> - add Kconfig depends on !TOUCHSCREEN_SUN4I,
> - remove Kconfig selects THERMAL_OF,
> - do not register thermal sensor if CONFIG_THERMAL_OF is disabled,
> - disable irq in irq_handler rather than in read_raw,
> - add delay when switching the IP's mode or channel (delay empirically found),
> - quicken thermal sensor interrupt period,
> - add masks for channel bits,
> - fix deadlock in sun4i_gpadc_read if regmap_read/write fails,
> - move some logic from sun4i_gpadc_read to sun4i_prepare_for_irq,
> - mark last busy for runtime_pm only on success in sun4i_gpadc_read,
> - remove cached values,
> - increase wait_for_completion_timeout timeout to 1s to be sure to not miss the
> thermal interrupt,
> - add voltage scale,
> - use devm_iio_device_register,
>
> v6:
> - remove "-mfd" from filenames and variables inside MFD driver,
> - use DEFINE_RES_IRQ_NAMED instead of setting resources manually,
> - cosmetic changes,
> - use IDs and switch over ID to get cells specific to an architecture, instead
> of using cells direclty, in of_device_id.data,
> - compute size of mfd_cells array instead of hardcoded one,
>
> v5:
> - correct mail address,
>
> v4:
> - rename files and variables from sunxi* to sun4i*,
> - rename defines from SUNXI_* to SUN4I_* or SUN6I_*,
> - remove TP in defines name,
> - rename SUNXI_IRQ_* to SUN4I_GPADC_IRQ_* for consistency,
> - use devm functions for regmap_add_irq_chip and mfd_add_devices,
> - remove remove functions (now empty thanks to devm functions),
>
> v3:
> - use defines in regmap_irq instead of hard coded BITs,
> - use of_device_id data field to chose which MFD cells to add considering
> the compatible responsible of the MFD probe,
> - remove useless initializations,
> - disable all interrupts before adding them to regmap_irqchip,
> - add goto error label in probe,
> - correct wrapping in header license,
> - move defines from IIO driver to header,
> - use GENMASK to limit the size of the variable passed to a macro,
> - prefix register BIT defines with the name of the register,
> - reorder defines,
>
> v2:
> - add license headers,
> - reorder alphabetically includes,
> - add SUNXI_GPADC_ prefixes for defines,
>
> drivers/iio/adc/Kconfig | 17 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/sun4i-gpadc-iio.c | 613 ++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/sun4i-gpadc.h | 2 +
> 4 files changed, 633 insertions(+)
> create mode 100644 drivers/iio/adc/sun4i-gpadc-iio.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 99c0514..6a6d369 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -434,6 +434,23 @@ config STX104
> The base port addresses for the devices may be configured via the base
> array module parameter.
>
> +config SUN4I_GPADC
> + tristate "Support for the Allwinner SoCs GPADC"
> + depends on IIO
> + depends on MFD_SUN4I_GPADC
> + help
> + Say yes here to build support for Allwinner (A10, A13 and A31) SoCs
> + GPADC. This ADC provides 4 channels which can be used as an ADC or as
> + a touchscreen input and one channel for thermal sensor.
> +
> + The thermal sensor slows down ADC readings and can be disabled by
> + disabling CONFIG_THERMAL_OF. However, the thermal sensor should be
> + enabled by default since the SoC temperature is usually more critical
> + than ADC readings.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called sun4i-gpadc-iio.
> +
> config TI_ADC081C
> tristate "Texas Instruments ADC081C/ADC101C/ADC121C family"
> depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 7a40c04..18ce8d6 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -41,6 +41,7 @@ obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
> obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_STX104) += stx104.o
> +obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
> new file mode 100644
> index 0000000..a8e134f
> --- /dev/null
> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
> @@ -0,0 +1,613 @@
> +/* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
> + *
> + * 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.
> + *
> + * The Allwinner SoCs all have an ADC that can also act as a touchscreen
> + * controller and a thermal sensor.
> + * The thermal sensor works only when the ADC acts as a touchscreen controller
> + * and is configured to throw an interrupt every fixed periods of time (let say
> + * every X seconds).
> + * One would be tempted to disable the IP on the hardware side rather than
> + * disabling interrupts to save some power but that resets the internal clock of
> + * the IP, resulting in having to wait X seconds every time we want to read the
> + * value of the thermal sensor.
> + * This is also the reason of using autosuspend in pm_runtime. If there was no
> + * autosuspend, the thermal sensor would need X seconds after every
> + * pm_runtime_get_sync to get a value from the ADC. The autosuspend allows the
> + * thermal sensor to be requested again in a certain time span before it gets
> + * shutdown for not being used.
> + */
> +
> +#include <linux/completion.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/thermal.h>
> +#include <linux/delay.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/mfd/sun4i-gpadc.h>
> +
> +static unsigned int sun4i_gpadc_chan_select(unsigned int chan)
> +{
> + return SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
> +}
> +
> +static unsigned int sun6i_gpadc_chan_select(unsigned int chan)
> +{
> + return SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(chan);
> +}
> +
> +struct gpadc_data {
> + int temp_offset;
> + int temp_scale;
> + unsigned int tp_mode_en;
> + unsigned int tp_adc_select;
> + unsigned int (*adc_chan_select)(unsigned int chan);
> + unsigned int adc_chan_mask;
> +};
> +
> +static const struct gpadc_data sun4i_gpadc_data = {
> + .temp_offset = -1932,
> + .temp_scale = 133,
> + .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
> + .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
> + .adc_chan_select = &sun4i_gpadc_chan_select,
> + .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
> +};
> +
> +static const struct gpadc_data sun5i_gpadc_data = {
> + .temp_offset = -1447,
> + .temp_scale = 100,
> + .tp_mode_en = SUN4I_GPADC_CTRL1_TP_MODE_EN,
> + .tp_adc_select = SUN4I_GPADC_CTRL1_TP_ADC_SELECT,
> + .adc_chan_select = &sun4i_gpadc_chan_select,
> + .adc_chan_mask = SUN4I_GPADC_CTRL1_ADC_CHAN_MASK,
> +};
> +
> +static const struct gpadc_data sun6i_gpadc_data = {
> + .temp_offset = -1623,
> + .temp_scale = 167,
> + .tp_mode_en = SUN6I_GPADC_CTRL1_TP_MODE_EN,
> + .tp_adc_select = SUN6I_GPADC_CTRL1_TP_ADC_SELECT,
> + .adc_chan_select = &sun6i_gpadc_chan_select,
> + .adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
> +};
> +
> +struct sun4i_gpadc_iio {
> + struct iio_dev *indio_dev;
> + struct completion completion;
> + int temp_data;
> + u32 adc_data;
> + struct regmap *regmap;
> + unsigned int fifo_data_irq;
> + atomic_t ignore_fifo_data_irq;
> + unsigned int temp_data_irq;
> + atomic_t ignore_temp_data_irq;
> + const struct gpadc_data *data;
> + /* prevents concurrent reads of temperature and ADC */
> + struct mutex mutex;
> +};
> +
> +#define SUN4I_GPADC_ADC_CHANNEL(_channel, _name) { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = _channel, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .datasheet_name = _name, \
> +}
> +
> +static struct iio_map sun4i_gpadc_hwmon_maps[] = {
> + {
> + .adc_channel_label = "temp_adc",
> + .consumer_dev_name = "iio_hwmon.0",
It's theoretically possible we have another one of these which will make
life interesting. Oh well, no easy way around that at the mo...
> + },
> + { /* sentinel */ },
> +};
> +
> +static const struct iio_chan_spec sun4i_gpadc_channels[] = {
> + SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
> + SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
> + SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
> + SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
> + {
> + .type = IIO_TEMP,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) |
> + BIT(IIO_CHAN_INFO_OFFSET),
> + .datasheet_name = "temp_adc",
> + },
> +};
> +
> +static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = {
> + SUN4I_GPADC_ADC_CHANNEL(0, "adc_chan0"),
> + SUN4I_GPADC_ADC_CHANNEL(1, "adc_chan1"),
> + SUN4I_GPADC_ADC_CHANNEL(2, "adc_chan2"),
> + SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
> +};
> +
> +static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel,
> + unsigned int irq)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> + int ret;
> + u32 reg;
> +
> + pm_runtime_get_sync(indio_dev->dev.parent);
> +
> + reinit_completion(&info->completion);
> +
> + ret = regmap_write(info->regmap, SUN4I_GPADC_INT_FIFOC,
> + SUN4I_GPADC_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
> + SUN4I_GPADC_INT_FIFOC_TP_FIFO_FLUSH);
> + if (ret)
> + return ret;
> +
> + ret = regmap_read(info->regmap, SUN4I_GPADC_CTRL1, ®);
> + if (ret)
> + return ret;
> +
> + if (irq == info->fifo_data_irq) {
> + ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
> + info->data->tp_mode_en |
> + info->data->tp_adc_select |
> + info->data->adc_chan_select(channel));
> + /*
> + * When the IP changes channel, it needs a bit of time to get
> + * correct values.
> + */
> + if ((reg & info->data->adc_chan_mask) !=
> + info->data->adc_chan_select(channel))
> + mdelay(10);
> +
> + } else {
> + /*
> + * The temperature sensor returns valid data only when the ADC
> + * operates in touchscreen mode.
> + */
> + ret = regmap_write(info->regmap, SUN4I_GPADC_CTRL1,
> + info->data->tp_mode_en);
> + }
> +
> + if (ret)
> + return ret;
> +
> + /*
> + * When the IP changes mode between ADC or touchscreen, it
> + * needs a bit of time to get correct values.
> + */
> + if ((reg & info->data->tp_adc_select) != info->data->tp_adc_select)
> + mdelay(100);
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_read(struct iio_dev *indio_dev, int channel, int *val,
> + unsigned int irq)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&info->mutex);
> +
> + ret = sun4i_prepare_for_irq(indio_dev, channel, irq);
> + if (ret)
> + goto err;
> +
> + enable_irq(irq);
> +
> + /*
> + * The temperature sensor throws an interruption periodically (currently
> + * set at periods of ~0.6s in sun4i_gpadc_runtime_resume). A 1s delay
> + * makes sure an interruption occurs in normal conditions. If it doesn't
> + * occur, then there is a timeout.
> + */
> + if (!wait_for_completion_timeout(&info->completion,
> + msecs_to_jiffies(1000))) {
> + ret = -ETIMEDOUT;
> + goto err;
> + }
> +
> + if (irq == info->fifo_data_irq)
> + *val = info->adc_data;
> + else
> + *val = info->temp_data;
> +
> + ret = 0;
> + pm_runtime_mark_last_busy(indio_dev->dev.parent);
> +
> +err:
> + pm_runtime_put_autosuspend(indio_dev->dev.parent);
> + mutex_unlock(&info->mutex);
> +
> + return ret;
> +}
> +
> +static int sun4i_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
> + int *val)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> +
> + return sun4i_gpadc_read(indio_dev, channel, val, info->fifo_data_irq);
> +}
> +
> +static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> +
> + return sun4i_gpadc_read(indio_dev, 0, val, info->temp_data_irq);
> +}
> +
> +static int sun4i_gpadc_temp_offset(struct iio_dev *indio_dev, int *val)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> +
> + *val = info->data->temp_offset;
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_temp_scale(struct iio_dev *indio_dev, int *val)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
> +
> + *val = info->data->temp_scale;
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_OFFSET:
> + ret = sun4i_gpadc_temp_offset(indio_dev, val);
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_RAW:
> + if (chan->type == IIO_VOLTAGE)
> + ret = sun4i_gpadc_adc_read(indio_dev, chan->channel,
> + val);
> + else
> + ret = sun4i_gpadc_temp_read(indio_dev, val);
> +
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_VOLTAGE) {
> + /* 3000mV / 4096 * raw */
> + *val = 0;
> + *val2 = 732421875;
> + return IIO_VAL_INT_PLUS_NANO;
> + }
> +
> + ret = sun4i_gpadc_temp_scale(indio_dev, val);
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info sun4i_gpadc_iio_info = {
> + .read_raw = sun4i_gpadc_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static irqreturn_t sun4i_gpadc_temp_data_irq_handler(int irq, void *dev_id)
> +{
> + struct sun4i_gpadc_iio *info = dev_id;
> +
> + if (atomic_read(&info->ignore_temp_data_irq))
> + goto out;
> +
> + if (!regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, &info->temp_data))
> + complete(&info->completion);
> +
> +out:
> + disable_irq_nosync(info->temp_data_irq);
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t sun4i_gpadc_fifo_data_irq_handler(int irq, void *dev_id)
> +{
> + struct sun4i_gpadc_iio *info = dev_id;
> +
> + if (atomic_read(&info->ignore_fifo_data_irq))
> + goto out;
> +
> + if (!regmap_read(info->regmap, SUN4I_GPADC_DATA, &info->adc_data))
> + complete(&info->completion);
> +
> +out:
> + disable_irq_nosync(info->fifo_data_irq);
> + return IRQ_HANDLED;
> +}
> +
> +static int sun4i_gpadc_runtime_suspend(struct device *dev)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
> +
> + /* Disable the ADC on IP */
> + regmap_write(info->regmap, SUN4I_GPADC_CTRL1, 0);
> + /* Disable temperature sensor on IP */
> + regmap_write(info->regmap, SUN4I_GPADC_TPR, 0);
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_runtime_resume(struct device *dev)
> +{
> + struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev));
> +
> + /* clkin = 6MHz */
> + regmap_write(info->regmap, SUN4I_GPADC_CTRL0,
> + SUN4I_GPADC_CTRL0_ADC_CLK_DIVIDER(2) |
> + SUN4I_GPADC_CTRL0_FS_DIV(7) |
> + SUN4I_GPADC_CTRL0_T_ACQ(63));
> + regmap_write(info->regmap, SUN4I_GPADC_CTRL1, info->data->tp_mode_en);
> + regmap_write(info->regmap, SUN4I_GPADC_CTRL3,
> + SUN4I_GPADC_CTRL3_FILTER_EN |
> + SUN4I_GPADC_CTRL3_FILTER_TYPE(1));
> + /* period = SUN4I_GPADC_TPR_TEMP_PERIOD * 256 * 16 / clkin; ~0.6s */
> + regmap_write(info->regmap, SUN4I_GPADC_TPR,
> + SUN4I_GPADC_TPR_TEMP_ENABLE |
> + SUN4I_GPADC_TPR_TEMP_PERIOD(800));
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_get_temp(void *data, int *temp)
> +{
> + struct sun4i_gpadc_iio *info = (struct sun4i_gpadc_iio *)data;
> + int val, scale, offset;
> +
> + if (sun4i_gpadc_temp_read(info->indio_dev, &val))
> + return -ETIMEDOUT;
> +
> + sun4i_gpadc_temp_scale(info->indio_dev, &scale);
> + sun4i_gpadc_temp_offset(info->indio_dev, &offset);
> +
> + *temp = (val + offset) * scale;
> +
> + return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
> + .get_temp = &sun4i_gpadc_get_temp,
> +};
> +
> +static const struct dev_pm_ops sun4i_gpadc_pm_ops = {
> + .runtime_suspend = &sun4i_gpadc_runtime_suspend,
> + .runtime_resume = &sun4i_gpadc_runtime_resume,
> +};
> +
> +static int sun4i_irq_init(struct platform_device *pdev, const char *name,
> + irq_handler_t handler, const char *devname,
> + unsigned int *irq, atomic_t *atomic)
> +{
> + int ret;
> + struct sun4i_gpadc_dev *mfd_dev = dev_get_drvdata(pdev->dev.parent);
> + struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(&pdev->dev));
> +
> + /*
> + * Once the interrupt is activated, the IP continuously performs
> + * conversions thus throws interrupts. The interrupt is activated right
> + * after being requested but we want to control when these interrupts
> + * occur thus we disable it right after being requested. However, an
> + * interrupt might occur between these two instructions and we have to
> + * make sure that does not happen, by using atomic flags. We set the
> + * flag before requesting the interrupt and unset it right after
> + * disabling the interrupt. When an interrupt occurs between these two
> + * instructions, reading the atomic flag will tell us to ignore the
> + * interrupt.
> + */
> + atomic_set(atomic, 1);
> +
> + ret = platform_get_irq_byname(pdev, name);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "no %s interrupt registered\n", name);
> + return ret;
> + }
> +
> + ret = regmap_irq_get_virq(mfd_dev->regmap_irqc, ret);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to get virq for irq %s\n", name);
> + return ret;
> + }
> +
> + *irq = ret;
> + ret = devm_request_any_context_irq(&pdev->dev, *irq, handler, 0,
> + devname, info);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not request %s interrupt: %d\n",
> + name, ret);
> + return ret;
> + }
> +
> + disable_irq(*irq);
> + atomic_set(atomic, 0);
> +
> + return 0;
> +}
> +
> +static int sun4i_gpadc_probe(struct platform_device *pdev)
> +{
> + struct sun4i_gpadc_iio *info;
> + struct iio_dev *indio_dev;
> + int ret;
> + struct sun4i_gpadc_dev *sun4i_gpadc_dev;
> +
> + sun4i_gpadc_dev = 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);
> + platform_set_drvdata(pdev, indio_dev);
> +
> + mutex_init(&info->mutex);
> + info->regmap = sun4i_gpadc_dev->regmap;
> + info->indio_dev = indio_dev;
> + init_completion(&info->completion);
> + indio_dev->name = dev_name(&pdev->dev);
> + indio_dev->dev.parent = &pdev->dev;
> + indio_dev->dev.of_node = pdev->dev.of_node;
> + indio_dev->info = &sun4i_gpadc_iio_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels);
> + indio_dev->channels = sun4i_gpadc_channels;
> +
> + info->data = (struct gpadc_data *)platform_get_device_id(pdev)->driver_data;
> +
> + /*
> + * Since the controller needs to be in touchscreen mode for its thermal
> + * sensor to operate properly, and that switching between the two modes
> + * needs a delay, always registering in the thermal framework will
> + * significantly slow down the conversion rate of the ADCs.
> + *
> + * Therefore, instead of depending on THERMAL_OF in Kconfig, we only
> + * register the sensor if that option is enabled, eventually leaving
> + * that choice to the user.
> + */
> +
> + if (IS_ENABLED(CONFIG_THERMAL_OF)) {
> + /*
> + * This driver is a child of an MFD which has a node in the DT
> + * but not its children, because of DT backward compatibility
> + * for A10, A13 and A31 SoCs. Therefore, the resulting devices
> + * of this driver do not have an of_node variable.
> + * However, its parent (the MFD driver) has an of_node variable
> + * and since devm_thermal_zone_of_sensor_register uses its first
> + * argument to match the phandle defined in the node of the
> + * thermal driver with the of_node of the device passed as first
> + * argument and the third argument to call ops from
> + * thermal_zone_of_device_ops, the solution is to use the parent
> + * device as first argument to match the phandle with its
> + * of_node, and the device from this driver as third argument to
> + * return the temperature.
> + */
> + struct thermal_zone_device *tzd;
> + tzd = devm_thermal_zone_of_sensor_register(pdev->dev.parent, 0,
> + info,
> + &sun4i_ts_tz_ops);
> + if (IS_ERR(tzd)) {
> + dev_err(&pdev->dev,
> + "could not register thermal sensor: %ld\n",
> + PTR_ERR(tzd));
> + ret = PTR_ERR(tzd);
> + goto err;
> + }
> + } else {
> + indio_dev->num_channels =
> + ARRAY_SIZE(sun4i_gpadc_channels_no_temp);
> + indio_dev->channels = sun4i_gpadc_channels_no_temp;
> + }
> +
> + pm_runtime_set_autosuspend_delay(&pdev->dev,
> + SUN4I_GPADC_AUTOSUSPEND_DELAY);
> + pm_runtime_use_autosuspend(&pdev->dev);
> + pm_runtime_set_suspended(&pdev->dev);
> + pm_runtime_enable(&pdev->dev);
> +
> + if (IS_ENABLED(CONFIG_THERMAL_OF)) {
> + ret = sun4i_irq_init(pdev, "TEMP_DATA_PENDING",
> + sun4i_gpadc_temp_data_irq_handler,
> + "temp_data", &info->temp_data_irq,
> + &info->ignore_temp_data_irq);
> + if (ret < 0)
> + goto err;
> + }
> +
> + ret = sun4i_irq_init(pdev, "FIFO_DATA_PENDING",
> + sun4i_gpadc_fifo_data_irq_handler, "fifo_data",
> + &info->fifo_data_irq, &info->ignore_fifo_data_irq);
> + if (ret < 0)
> + goto err;
> +
> + if (IS_ENABLED(CONFIG_THERMAL_OF)) {
> + ret = iio_map_array_register(indio_dev, sun4i_gpadc_hwmon_maps);
> + if (ret < 0) {
> + dev_err(&pdev->dev,
> + "failed to register iio map array\n");
> + goto err;
> + }
> + }
> +
> + ret = devm_iio_device_register(&pdev->dev, indio_dev);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not register the device\n");
> + goto err_map;
> + }
> +
> + return 0;
> +
> +err_map:
> + if (IS_ENABLED(CONFIG_THERMAL_OF))
> + iio_map_array_unregister(indio_dev);
> +
> +err:
> + pm_runtime_put(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> +
> + return ret;
> +}
> +
> +static int sun4i_gpadc_remove(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +
> + pm_runtime_put(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> + if (IS_ENABLED(CONFIG_THERMAL_OF))
> + iio_map_array_unregister(indio_dev);
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id sun4i_gpadc_id[] = {
> + { "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_data },
> + { "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_data },
> + { "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_data },
> + { /* sentinel */ },
> +};
> +
> +static struct platform_driver sun4i_gpadc_driver = {
> + .driver = {
> + .name = "sun4i-gpadc-iio",
> + .pm = &sun4i_gpadc_pm_ops,
> + },
> + .id_table = sun4i_gpadc_id,
> + .probe = sun4i_gpadc_probe,
> + .remove = sun4i_gpadc_remove,
> +};
> +
> +module_platform_driver(sun4i_gpadc_driver);
> +
> +MODULE_DESCRIPTION("ADC driver for sunxi platforms");
> +MODULE_AUTHOR("Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/sun4i-gpadc.h b/include/linux/mfd/sun4i-gpadc.h
> index d7a29f2..509e736 100644
> --- a/include/linux/mfd/sun4i-gpadc.h
> +++ b/include/linux/mfd/sun4i-gpadc.h
> @@ -28,6 +28,7 @@
> #define SUN4I_GPADC_CTRL1_TP_MODE_EN BIT(4)
> #define SUN4I_GPADC_CTRL1_TP_ADC_SELECT BIT(3)
> #define SUN4I_GPADC_CTRL1_ADC_CHAN_SELECT(x) (GENMASK(2, 0) & (x))
> +#define SUN4I_GPADC_CTRL1_ADC_CHAN_MASK GENMASK(2, 0)
>
> /* TP_CTRL1 bits for sun6i SOCs */
> #define SUN6I_GPADC_CTRL1_TOUCH_PAN_CALI_EN BIT(7)
> @@ -35,6 +36,7 @@
> #define SUN6I_GPADC_CTRL1_TP_MODE_EN BIT(5)
> #define SUN6I_GPADC_CTRL1_TP_ADC_SELECT BIT(4)
> #define SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(x) (GENMASK(3, 0) & BIT(x))
> +#define SUN6I_GPADC_CTRL1_ADC_CHAN_MASK GENMASK(3, 0)
>
> #define SUN4I_GPADC_CTRL2 0x08
>
>