[PATCH v9 3/3] iio: adc: add support for Allwinner SoCs ADC
Quentin Schulz
quentin.schulz at free-electrons.com
Mon Mar 6 04:16:01 PST 2017
Hi Jonathan,
On 06/02/2017 19:35, Jonathan Cameron wrote:
> On 06/02/17 07:37, Quentin Schulz wrote:
>> 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.
> Gah! Sorry, I completely lost this one in my patch queue. Thanks for the
> reminder.
>
> Applied to the togreg branch of iio.git and pushed out as testing for the
> autobuilders to play with it.
>
> I'm afraid due to my tardiness it's missed the coming merge window, but
> I'll make sure it goes in my first pull request for the next cycle.
>
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,
>>>> 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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