linux/drivers/iio/adc/sun4i-gpadc-iio.c
Uwe Kleine-König 794c760fd3 iio: adc: sun4i-gpadc-iio: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230919174931.1417681-25-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2023-09-23 15:06:54 +01:00

712 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* ADC driver for sunxi platforms' (A10, A13 and A31) GPADC
*
* Copyright (c) 2016 Quentin Schulz <quentin.schulz@free-electrons.com>
*
* 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/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,
};
static const struct gpadc_data sun8i_a33_gpadc_data = {
.temp_offset = -1662,
.temp_scale = 162,
.tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
};
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;
bool no_irq;
/* prevents concurrent reads of temperature and ADC */
struct mutex mutex;
struct thermal_zone_device *tzd;
struct device *sensor_device;
};
#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",
},
{ /* 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 const struct iio_chan_spec sun8i_a33_gpadc_channels[] = {
{
.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 regmap_config sun4i_gpadc_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
.fast_io = true,
};
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, &reg);
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);
disable_irq(irq);
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);
if (info->no_irq) {
pm_runtime_get_sync(indio_dev->dev.parent);
regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, val);
pm_runtime_mark_last_busy(indio_dev->dev.parent);
pm_runtime_put_autosuspend(indio_dev->dev.parent);
return 0;
}
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,
};
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:
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:
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(struct thermal_zone_device *tz, int *temp)
{
struct sun4i_gpadc_iio *info = thermal_zone_device_priv(tz);
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_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)
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,
IRQF_NO_AUTOEN,
devname, info);
if (ret < 0) {
dev_err(&pdev->dev, "could not request %s interrupt: %d\n",
name, ret);
return ret;
}
atomic_set(atomic, 0);
return 0;
}
static const struct of_device_id sun4i_gpadc_of_id[] = {
{
.compatible = "allwinner,sun8i-a33-ths",
.data = &sun8i_a33_gpadc_data,
},
{ /* sentinel */ }
};
static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
struct iio_dev *indio_dev)
{
struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
void __iomem *base;
int ret;
info->data = of_device_get_match_data(&pdev->dev);
if (!info->data)
return -ENODEV;
info->no_irq = true;
indio_dev->num_channels = ARRAY_SIZE(sun8i_a33_gpadc_channels);
indio_dev->channels = sun8i_a33_gpadc_channels;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
info->regmap = devm_regmap_init_mmio(&pdev->dev, base,
&sun4i_gpadc_regmap_config);
if (IS_ERR(info->regmap)) {
ret = PTR_ERR(info->regmap);
dev_err(&pdev->dev, "failed to init regmap: %d\n", ret);
return ret;
}
if (IS_ENABLED(CONFIG_THERMAL_OF))
info->sensor_device = &pdev->dev;
return 0;
}
static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
struct iio_dev *indio_dev)
{
struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
struct sun4i_gpadc_dev *sun4i_gpadc_dev =
dev_get_drvdata(pdev->dev.parent);
int ret;
info->no_irq = false;
info->regmap = sun4i_gpadc_dev->regmap;
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.
*/
info->sensor_device = pdev->dev.parent;
} else {
indio_dev->num_channels =
ARRAY_SIZE(sun4i_gpadc_channels_no_temp);
indio_dev->channels = sun4i_gpadc_channels_no_temp;
}
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)
return ret;
}
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)
return ret;
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");
return ret;
}
}
return 0;
}
static int sun4i_gpadc_probe(struct platform_device *pdev)
{
struct sun4i_gpadc_iio *info;
struct iio_dev *indio_dev;
int ret;
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->indio_dev = indio_dev;
init_completion(&info->completion);
indio_dev->name = dev_name(&pdev->dev);
indio_dev->info = &sun4i_gpadc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
if (pdev->dev.of_node)
ret = sun4i_gpadc_probe_dt(pdev, indio_dev);
else
ret = sun4i_gpadc_probe_mfd(pdev, indio_dev);
if (ret)
return ret;
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)) {
info->tzd = devm_thermal_of_zone_register(info->sensor_device,
0, info,
&sun4i_ts_tz_ops);
/*
* Do not fail driver probing when failing to register in
* thermal because no thermal DT node is found.
*/
if (IS_ERR(info->tzd) && PTR_ERR(info->tzd) != -ENODEV) {
dev_err(&pdev->dev,
"could not register thermal sensor: %ld\n",
PTR_ERR(info->tzd));
return PTR_ERR(info->tzd);
}
}
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 (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF))
iio_map_array_unregister(indio_dev);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return ret;
}
static void sun4i_gpadc_remove(struct platform_device *pdev)
{
struct iio_dev *indio_dev = platform_get_drvdata(pdev);
struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
if (!IS_ENABLED(CONFIG_THERMAL_OF))
return;
if (!info->no_irq)
iio_map_array_unregister(indio_dev);
}
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 */ },
};
MODULE_DEVICE_TABLE(platform, sun4i_gpadc_id);
static struct platform_driver sun4i_gpadc_driver = {
.driver = {
.name = "sun4i-gpadc-iio",
.of_match_table = sun4i_gpadc_of_id,
.pm = &sun4i_gpadc_pm_ops,
},
.id_table = sun4i_gpadc_id,
.probe = sun4i_gpadc_probe,
.remove_new = sun4i_gpadc_remove,
};
MODULE_DEVICE_TABLE(of, sun4i_gpadc_of_id);
module_platform_driver(sun4i_gpadc_driver);
MODULE_DESCRIPTION("ADC driver for sunxi platforms");
MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
MODULE_LICENSE("GPL v2");