Re: [PATCH v3 4/4] iio: adc: add support for Allwinner SoCs ADC

Jonathan Cameron
2016-08-21T19:27:59Z

On 26/07/16 08:43, 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.
>
> 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@free-electrons.com>
> ---
>
> I don't like how I get the temperature for the thermal framework
> (sunxi_gpadc_get_temp). I am doing the exact same process as the iio_hwmon
> but in this function. This is duplicated code. I could use
> iio_read_channel_processed but it needs to have the iio_channel structure
> of the thermal sensor which I can only get with iio_channel_get which
> matches the device name with the consumer_dev_name in the iio_map array.
> And frankly, I do not see myself declaring the driver both as the producer
> and the consumer of IIO channels.
I also can't see a clean way of reusing the value calculation code. You
could construct and iio_channel by hand easily enough, but that would be
a pretty ugly bit of 'boundary crossing'.
>
> Moreover, since the thermal sensor is configured to throw an interrupt
> every X seconds, only the first request within these X seconds will not
> time out. This means that because the thermal framework regularly poll the
> thermal sensor, it is really difficult to get a value from sysfs without
> getting first a tonne of times out. I don't know if we can do something
> about that?
Cache the value what ever read it? (thermal or sysfs) then return that
until a new one shows up...

Otherwise, I don't have anything to add to the other review comments.

Jonathan
>
> v3:
> - correct wrapping,
> - add comment about thermal sensor inner working,
> - move defines in mfd header,
> - use structure to define SoC specific registers or behaviour,
> - attach this structure to the device according to of_device_id of the
> platform device,
> - use new mutex instead of iio_dev mutex,
> - use atomic flags to avoid race between request_irq and disable_irq in
> probe,
> - switch from processed value to raw, offset and scale values for
> temperature ADC channel,
> - remove faulty sentinel in iio_chan_spec array,
> - add pm_runtime support,
> - register thermal sensor in thermal framework (forgotten since the
> beginning whereas it is present in current sun4i-ts driver),
> - remove useless ret variables to store return value of regmap_reads,
> - move comments on thermal sensor acquisition period in code instead of
> header,
> - adding goto label to unregister iio_map_array when failing to register
> iio_dev,
>
> v2:
> - add SUNXI_GPADC_ prefixes for defines,
> - correct typo in Kconfig,
> - reorder alphabetically includes, makefile,
> - add license header,
> - fix architecture variations not being handled in interrupt handlers or
> read raw functions,
> - fix unability to return negative values from thermal sensor,
> - add gotos to reduce code repetition,
> - fix irq variable being unsigned int instead of int,
> - remove useless dev_err and dev_info,
> - deactivate all interrupts if probe fails,
> - fix iio_device_register on NULL variable,
> - deactivate ADC in the IP when probe fails or when removing driver,
>
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/sunxi-gpadc-iio.c | 513 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 526 insertions(+)
> create mode 100644 drivers/iio/adc/sunxi-gpadc-iio.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 25378c5..429ef16 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -384,6 +384,18 @@ config ROCKCHIP_SARADC
> To compile this driver as a module, choose M here: the
> module will be called rockchip_saradc.
>
> +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.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called sunxi-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 38638d4..14d1739 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -37,6 +37,7 @@ obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> obj-$(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-$(CONFIG_SUN4I_GPADC) += sunxi-gpadc-iio.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
> diff --git a/drivers/iio/adc/sunxi-gpadc-iio.c b/drivers/iio/adc/sunxi-gpadc-iio.c
> new file mode 100644
> index 0000000..5647688
> --- /dev/null
> +++ b/drivers/iio/adc/sunxi-gpadc-iio.c
> @@ -0,0 +1,513 @@
> +/* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
> + *
> + * Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons>
> + *
> + * 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 reset 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 were 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/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/iio/machine.h>
> +#include <linux/mfd/sunxi-gpadc-mfd.h>
> +
> +const unsigned int sun4i_gpadc_chan_select(unsigned int chan)
> +{
> + return SUNXI_GPADC_TP_CTRL1_ADC_CHAN_SELECT(chan);
> +}
> +
> +const unsigned int sun6i_gpadc_chan_select(unsigned int chan)
> +{
> + return SUNXI_GPADC_TP_CTRL1_SUN6I_ADC_CHAN_SELECT(chan);
> +}
> +
> +struct sunxi_gpadc_soc_specific {
> + const int temp_offset;
> + const int temp_scale;
> + const unsigned int tp_mode_en;
> + const unsigned int tp_adc_select;
> + const unsigned int (*adc_chan_select)(unsigned int chan);
> +};
> +
> +static const struct sunxi_gpadc_soc_specific sun4i_gpadc_soc_specific = {
> + .temp_offset = -1932,
> + .temp_scale = 133,
> + .tp_mode_en = SUNXI_GPADC_TP_CTRL1_TP_MODE_EN,
> + .tp_adc_select = SUNXI_GPADC_TP_CTRL1_TP_ADC_SELECT,
> + .adc_chan_select = &sun4i_gpadc_chan_select,
> +};
> +
> +static const struct sunxi_gpadc_soc_specific sun5i_gpadc_soc_specific = {
> + .temp_offset = -1447,
> + .temp_scale = 100,
> + .tp_mode_en = SUNXI_GPADC_TP_CTRL1_TP_MODE_EN,
> + .tp_adc_select = SUNXI_GPADC_TP_CTRL1_TP_ADC_SELECT,
> + .adc_chan_select = &sun4i_gpadc_chan_select,
> +};
> +
> +static const struct sunxi_gpadc_soc_specific sun6i_gpadc_soc_specific = {
> + .temp_offset = -1623,
> + .temp_scale = 167,
> + .tp_mode_en = SUNXI_GPADC_TP_CTRL1_SUN6I_TP_MODE_EN,
> + .tp_adc_select = SUNXI_GPADC_TP_CTRL1_SUN6I_TP_ADC_SELECT,
> + .adc_chan_select = &sun6i_gpadc_chan_select,
> +};
> +
> +struct sunxi_gpadc_dev {
> + struct iio_dev *indio_dev;
> + void __iomem *regs;
> + 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 sunxi_gpadc_soc_specific *soc_specific;
> + struct mutex mutex;
> +};
> +
> +#define SUNXI_GPADC_ADC_CHANNEL(_channel, _name) { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = _channel, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .datasheet_name = _name, \
> +}
> +
> +static struct iio_map sunxi_gpadc_hwmon_maps[] = {
> + {
> + .adc_channel_label = "temp_adc",
> + .consumer_dev_name = "iio_hwmon.0",
> + },
> + { /* sentinel */ },
> +};
> +
> +static const struct iio_chan_spec sunxi_gpadc_channels[] = {
> + SUNXI_GPADC_ADC_CHANNEL(0, "adc_chan0"),
> + SUNXI_GPADC_ADC_CHANNEL(1, "adc_chan1"),
> + SUNXI_GPADC_ADC_CHANNEL(2, "adc_chan2"),
> + SUNXI_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 int sunxi_gpadc_adc_read(struct iio_dev *indio_dev, int channel,
> + int *val)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(indio_dev);
> + int ret = 0;
> +
> + pm_runtime_get_sync(indio_dev->dev.parent);
> + mutex_lock(&info->mutex);
> +
> + reinit_completion(&info->completion);
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL1,
> + info->soc_specific->tp_mode_en |
> + info->soc_specific->tp_adc_select |
> + info->soc_specific->adc_chan_select(channel));
> + regmap_write(info->regmap, SUNXI_GPADC_TP_INT_FIFOC,
> + SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
> + SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_FLUSH);
> + enable_irq(info->fifo_data_irq);
> +
> + if (!wait_for_completion_timeout(&info->completion,
> + msecs_to_jiffies(100))) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + *val = info->adc_data;
> +
> +out:
> + disable_irq(info->fifo_data_irq);
> + mutex_unlock(&info->mutex);
> + pm_runtime_mark_last_busy(indio_dev->dev.parent);
> + pm_runtime_put_autosuspend(indio_dev->dev.parent);
> +
> + return ret;
> +}
> +
> +static int sunxi_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(indio_dev);
> + int ret = 0;
> +
> + pm_runtime_get_sync(indio_dev->dev.parent);
> + mutex_lock(&info->mutex);
> +
> + reinit_completion(&info->completion);
> +
> + regmap_write(info->regmap, SUNXI_GPADC_TP_INT_FIFOC,
> + SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_TRIG_LEVEL(1) |
> + SUNXI_GPADC_TP_INT_FIFOC_TP_FIFO_FLUSH);
> + /*
> + * The temperature sensor returns valid data only when the ADC operates
> + * in touchscreen mode.
> + */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL1,
> + info->soc_specific->tp_mode_en);
> + enable_irq(info->temp_data_irq);
> +
> + if (!wait_for_completion_timeout(&info->completion,
> + msecs_to_jiffies(100))) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + *val = info->temp_data;
> +
> +out:
> + disable_irq(info->temp_data_irq);
> + mutex_unlock(&info->mutex);
> + pm_runtime_mark_last_busy(indio_dev->dev.parent);
> + pm_runtime_put_autosuspend(indio_dev->dev.parent);
> +
> + return ret;
> +}
> +
> +static int sunxi_gpadc_temp_offset(struct iio_dev *indio_dev, int *val)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(indio_dev);
> +
> + *val = info->soc_specific->temp_offset;
> +
> + return 0;
> +}
> +
> +static int sunxi_gpadc_temp_scale(struct iio_dev *indio_dev, int *val)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(indio_dev);
> +
> + *val = info->soc_specific->temp_scale;
> +
> + return 0;
> +}
> +
> +static int sunxi_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 = sunxi_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 = sunxi_gpadc_adc_read(indio_dev, chan->channel,
> + val);
> + if (ret)
> + return ret;
> + } else {
> + ret = sunxi_gpadc_temp_read(indio_dev, val);
> + if (ret)
> + return ret;
> + }
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + ret = sunxi_gpadc_temp_scale(indio_dev, val);
> + if (ret)
> + return ret;
> +
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info sunxi_gpadc_iio_info = {
> + .read_raw = sunxi_gpadc_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static irqreturn_t sunxi_gpadc_temp_data_irq_handler(int irq, void *dev_id)
> +{
> + struct sunxi_gpadc_dev *info = dev_id;
> +
> + if (atomic_read(&info->ignore_temp_data_irq))
> + return IRQ_HANDLED;
> +
> + if (!regmap_read(info->regmap, SUNXI_GPADC_TEMP_DATA, &info->temp_data))
> + complete(&info->completion);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t sunxi_gpadc_fifo_data_irq_handler(int irq, void *dev_id)
> +{
> + struct sunxi_gpadc_dev *info = dev_id;
> +
> + if (atomic_read(&info->ignore_fifo_data_irq))
> + return IRQ_HANDLED;
> +
> + if (!regmap_read(info->regmap, SUNXI_GPADC_TP_DATA, &info->adc_data))
> + complete(&info->completion);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int sunxi_gpadc_runtime_suspend(struct device *dev)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(dev_get_drvdata(dev));
> +
> + mutex_lock(&info->mutex);
> +
> + /* Disable the ADC on IP */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL1, 0);
> + /* Disable temperature sensor on IP */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_TPR, 0);
> +
> + mutex_unlock(&info->mutex);
> +
> + return 0;
> +}
> +
> +static int sunxi_gpadc_runtime_resume(struct device *dev)
> +{
> + struct sunxi_gpadc_dev *info = iio_priv(dev_get_drvdata(dev));
> +
> + mutex_lock(&info->mutex);
> +
> + /* clkin = 6MHz */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL0,
> + SUNXI_GPADC_TP_CTRL0_ADC_CLK_DIVIDER(2) |
> + SUNXI_GPADC_TP_CTRL0_FS_DIV(7) |
> + SUNXI_GPADC_TP_CTRL0_T_ACQ(63));
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL1,
> + info->soc_specific->tp_mode_en);
> + regmap_write(info->regmap, SUNXI_GPADC_TP_CTRL3,
> + SUNXI_GPADC_TP_CTRL3_FILTER_EN |
> + SUNXI_GPADC_TP_CTRL3_FILTER_TYPE(1));
> + /* period = SUNXI_GPADC_TP_TPR_TEMP_PERIOD * 256 * 16 / clkin; ~1.3s */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_TPR,
> + SUNXI_GPADC_TP_TPR_TEMP_ENABLE |
> + SUNXI_GPADC_TP_TPR_TEMP_PERIOD(1953));
> +
> + mutex_unlock(&info->mutex);
> +
> + return 0;
> +}
> +
> +static int sunxi_gpadc_get_temp(void *data, int *temp)
> +{
> + struct sunxi_gpadc_dev *info = (struct sunxi_gpadc_dev *)data;
> + int val, scale, offset;
> +
> + /* If reading temperature times out, take stored previous value. */
> + if (sunxi_gpadc_temp_read(info->indio_dev, &val))
> + val = info->temp_data;
> + sunxi_gpadc_temp_scale(info->indio_dev, &scale);
> + sunxi_gpadc_temp_offset(info->indio_dev, &offset);
> +
> + *temp = (val + offset) * scale;
> +
> + return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops sunxi_ts_tz_ops = {
> + .get_temp = &sunxi_gpadc_get_temp,
> +};
> +
> +static const struct dev_pm_ops sunxi_gpadc_pm_ops = {
> + .runtime_suspend = &sunxi_gpadc_runtime_suspend,
> + .runtime_resume = &sunxi_gpadc_runtime_resume,
> +};
> +
> +static int sunxi_gpadc_probe(struct platform_device *pdev)
> +{
> + struct sunxi_gpadc_dev *info;
> + struct iio_dev *indio_dev;
> + int ret, irq;
> + struct sunxi_gpadc_mfd_dev *sunxi_gpadc_mfd_dev;
> + struct thermal_zone_device *tzd;
> +
> + sunxi_gpadc_mfd_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);
> +
> + mutex_init(&info->mutex);
> + info->regmap = sunxi_gpadc_mfd_dev->regmap;
> + info->indio_dev = indio_dev;
> + atomic_set(&info->ignore_fifo_data_irq, 1);
> + atomic_set(&info->ignore_temp_data_irq, 1);
> + 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 = &sunxi_gpadc_iio_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->num_channels = ARRAY_SIZE(sunxi_gpadc_channels);
> + indio_dev->channels = sunxi_gpadc_channels;
> +
> + info->soc_specific = (struct sunxi_gpadc_soc_specific *)platform_get_device_id(pdev)->driver_data;
> +
> + tzd = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, info,
> + &sunxi_ts_tz_ops);
> + if (IS_ERR(tzd)) {
> + dev_err(&pdev->dev, "could not register thermal sensor: %ld\n",
> + PTR_ERR(tzd));
> + return PTR_ERR(tzd);
> + }
> +
> + pm_runtime_set_autosuspend_delay(&pdev->dev,
> + SUNXI_GPADC_AUTOSUSPEND_DELAY);
> + pm_runtime_use_autosuspend(&pdev->dev);
> + pm_runtime_set_suspended(&pdev->dev);
> + pm_runtime_enable(&pdev->dev);
> +
> + irq = platform_get_irq_byname(pdev, "TEMP_DATA_PENDING");
> + if (irq < 0) {
> + dev_err(&pdev->dev,
> + "no TEMP_DATA_PENDING interrupt registered\n");
> + ret = irq;
> + goto err;
> + }
> +
> + irq = regmap_irq_get_virq(sunxi_gpadc_mfd_dev->regmap_irqc, irq);
> + ret = devm_request_any_context_irq(&pdev->dev, irq,
> + sunxi_gpadc_temp_data_irq_handler, 0,
> + "temp_data", info);
> + if (ret < 0) {
> + dev_err(&pdev->dev,
> + "could not request TEMP_DATA_PENDING interrupt: %d\n",
> + ret);
> + goto err;
> + }
> +
> + disable_irq(irq);
> + info->temp_data_irq = irq;
> + atomic_set(&info->ignore_temp_data_irq, 0);
> +
> + irq = platform_get_irq_byname(pdev, "FIFO_DATA_PENDING");
> + if (irq < 0) {
> + dev_err(&pdev->dev,
> + "no FIFO_DATA_PENDING interrupt registered\n");
> + ret = irq;
> + goto err;
> + }
> +
> + irq = regmap_irq_get_virq(sunxi_gpadc_mfd_dev->regmap_irqc, irq);
> + ret = devm_request_any_context_irq(&pdev->dev, irq,
> + sunxi_gpadc_fifo_data_irq_handler, 0,
> + "fifo_data", info);
> + if (ret < 0) {
> + dev_err(&pdev->dev,
> + "could not request FIFO_DATA_PENDING interrupt: %d\n",
> + ret);
> + goto err;
> + }
> +
> + disable_irq(irq);
> + info->fifo_data_irq = irq;
> + atomic_set(&info->ignore_fifo_data_irq, 0);
> +
> + ret = iio_map_array_register(indio_dev, sunxi_gpadc_hwmon_maps);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to register iio map array\n");
> + goto err;
> + }
> +
> + platform_set_drvdata(pdev, indio_dev);
> +
> + ret = iio_device_register(indio_dev);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not register the device\n");
> + goto err_map;
> + }
> +
> + return 0;
> +
> +err_map:
> + iio_map_array_unregister(indio_dev);
> +
> +err:
> + pm_runtime_put(&pdev->dev);
> + /* Disable all hardware interrupts */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_INT_FIFOC, 0);
> +
> + return ret;
> +}
> +
> +static int sunxi_gpadc_remove(struct platform_device *pdev)
> +{
> + struct sunxi_gpadc_dev *info;
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +
> + info = iio_priv(indio_dev);
> + iio_device_unregister(indio_dev);
> + iio_map_array_unregister(indio_dev);
> + pm_runtime_put(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> + /* Disable all hardware interrupts */
> + regmap_write(info->regmap, SUNXI_GPADC_TP_INT_FIFOC, 0);
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id sunxi_gpadc_id[] = {
> + { "sun4i-a10-gpadc-iio", (kernel_ulong_t)&sun4i_gpadc_soc_specific },
> + { "sun5i-a13-gpadc-iio", (kernel_ulong_t)&sun5i_gpadc_soc_specific },
> + { "sun6i-a31-gpadc-iio", (kernel_ulong_t)&sun6i_gpadc_soc_specific },
> + { /* sentinel */ },
> +};
> +
> +static struct platform_driver sunxi_gpadc_driver = {
> + .driver = {
> + .name = "sunxi-gpadc-iio",
> + .pm = &sunxi_gpadc_pm_ops,
> + },
> + .id_table = sunxi_gpadc_id,
> + .probe = sunxi_gpadc_probe,
> + .remove = sunxi_gpadc_remove,
> +};
> +
> +module_platform_driver(sunxi_gpadc_driver);
> +
> +MODULE_DESCRIPTION("ADC driver for sunxi platforms");
> +MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
> +MODULE_LICENSE("GPL v2");
>