[PATCH v9 3/3] iio: adc: add support for Allwinner SoCs ADC
Jonathan Cameron
jic23 at kernel.org
Sun Jan 8 03:17:43 PST 2017
On 30/12/16 14:40, Jonathan Cameron wrote:
> 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 at free-electrons.com>
>> Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
>> Acked-by: Jonathan Cameron <jic23 at kernel.org>
>> Acked-for-MFD-by: Lee Jones <lee.jones at linaro.org>
> 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.
Nothing seems to have come through on that front.
I need to get a pull request out to Greg and rebase my tree before I have
the precursor patch in place. Give me a bump if you haven't heard anything by
the time next week.
Thanks,
Jonathan
>
> 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 at free-electrons.com>
>> + *
>> + * 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 at free-electrons.com>");
>> +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
>>
>>
>
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