[PATCH v9 3/3] iio: adc: add support for Allwinner SoCs ADC
Quentin Schulz
quentin.schulz at free-electrons.com
Sun Feb 5 23:37:46 PST 2017
Hi Jonathan,
On 14/01/2017 20:28, Jonathan Cameron wrote:
>
>
> On 14 January 2017 19:19:58 GMT+00:00, Quentin Schulz <quentin.schulz at free-electrons.com> wrote:
>> Hi Jonathan,
>>
>> On 08/01/2017 12:17, Jonathan Cameron wrote:
>>> 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.
>>>
>>
>> Kindly "giving you a bump" you as requested since I haven't heard from
>> you for a week.
> Greg hasn't pulled yet, so may be a few more days.
>
> J
I haven't received any news from you on the merging of this patch series
for a month, so kindly pinging.
Thanks,
Quentin
>>
>> Thanks,
>> Quentin
>>
>>> 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
>>>>>
>>>>>
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-iio"
>> in
>>>> the body of a message to majordomo at vger.kernel.org
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>>
>>>
>
--
Quentin Schulz, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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