[PATCH v5 1/3] iio: adc: rockchip_saradc: move all of probe to devm-functions

[PATCH v5 1/3] iio: adc: rockchip_saradc: move all of probe to devm-functions

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

Parts of the saradc probe rely on devm functions and later parts do not.
This makes it more difficult to for example enable triggers via their
devm-functions and would need more undo-work in remove.

So to make life easier for the driver, move the rest of probe calls
also to their devm-equivalents.

This includes moving the clk- and regulator-disabling to a devm_action
so that they gets disabled both during remove and in the error case
in probe, after the action is registered.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
changes in v5:
- none
changes in v4:
- new patch as suggested by Jonathan

 drivers/iio/adc/rockchip_saradc.c | 37 ++++++++++++++++---------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
index 582ba047c4a6..270eb7e83823 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -193,6 +193,15 @@ static void rockchip_saradc_reset_controller(struct reset_control *reset)
 	reset_control_deassert(reset);
 }
 
+static void rockchip_saradc_disable(void *data)
+{
+	struct rockchip_saradc *info = data;
+
+	clk_disable_unprepare(info->clk);
+	clk_disable_unprepare(info->pclk);
+	regulator_disable(info->vref);
+}
+
 static int rockchip_saradc_probe(struct platform_device *pdev)
 {
 	struct rockchip_saradc *info = NULL;
@@ -304,6 +313,14 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 		goto err_pclk;
 	}
 
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rockchip_saradc_disable, info);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register devm action, %d\n",
+			ret);
+		return ret;
+	}
+
 	platform_set_drvdata(pdev, indio_dev);
 
 	indio_dev->name = dev_name(&pdev->dev);
@@ -315,14 +332,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 	indio_dev->channels = info->data->channels;
 	indio_dev->num_channels = info->data->num_channels;
 
-	ret = iio_device_register(indio_dev);
+	ret = devm_iio_device_register(&pdev->dev, indio_dev);
 	if (ret)
-		goto err_clk;
+		return ret;
 
 	return 0;
 
-err_clk:
-	clk_disable_unprepare(info->clk);
 err_pclk:
 	clk_disable_unprepare(info->pclk);
 err_reg_voltage:
@@ -330,19 +345,6 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int rockchip_saradc_remove(struct platform_device *pdev)
-{
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
-	struct rockchip_saradc *info = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	clk_disable_unprepare(info->clk);
-	clk_disable_unprepare(info->pclk);
-	regulator_disable(info->vref);
-
-	return 0;
-}
-
 #ifdef CONFIG_PM_SLEEP
 static int rockchip_saradc_suspend(struct device *dev)
 {
@@ -383,7 +385,6 @@ static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
 
 static struct platform_driver rockchip_saradc_driver = {
 	.probe		= rockchip_saradc_probe,
-	.remove		= rockchip_saradc_remove,
 	.driver		= {
 		.name	= "rockchip-saradc",
 		.of_match_table = rockchip_saradc_match,
-- 
2.25.1

[PATCH v5 2/3] iio: adc: rockchip_saradc: better prefix for channel constant

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>

As suggested give the current ADC_CHANNEL constant a distinct
and consistent prefix.

Suggested-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
changes in v5:
- new patch

 drivers/iio/adc/rockchip_saradc.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
index 270eb7e83823..29d7f6e4057e 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -118,7 +118,7 @@ static const struct iio_info rockchip_saradc_iio_info = {
 	.read_raw = rockchip_saradc_read_raw,
 };
 
-#define ADC_CHANNEL(_index, _id) {				\
+#define SARADC_CHANNEL(_index, _id) {				\
 	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.channel = _index,					\
@@ -128,9 +128,9 @@ static const struct iio_info rockchip_saradc_iio_info = {
 }
 
 static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
-	ADC_CHANNEL(0, "adc0"),
-	ADC_CHANNEL(1, "adc1"),
-	ADC_CHANNEL(2, "adc2"),
+	SARADC_CHANNEL(0, "adc0"),
+	SARADC_CHANNEL(1, "adc1"),
+	SARADC_CHANNEL(2, "adc2"),
 };
 
 static const struct rockchip_saradc_data saradc_data = {
@@ -141,8 +141,8 @@ static const struct rockchip_saradc_data saradc_data = {
 };
 
 static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
-	ADC_CHANNEL(0, "adc0"),
-	ADC_CHANNEL(1, "adc1"),
+	SARADC_CHANNEL(0, "adc0"),
+	SARADC_CHANNEL(1, "adc1"),
 };
 
 static const struct rockchip_saradc_data rk3066_tsadc_data = {
@@ -153,12 +153,12 @@ static const struct rockchip_saradc_data rk3066_tsadc_data = {
 };
 
 static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
-	ADC_CHANNEL(0, "adc0"),
-	ADC_CHANNEL(1, "adc1"),
-	ADC_CHANNEL(2, "adc2"),
-	ADC_CHANNEL(3, "adc3"),
-	ADC_CHANNEL(4, "adc4"),
-	ADC_CHANNEL(5, "adc5"),
+	SARADC_CHANNEL(0, "adc0"),
+	SARADC_CHANNEL(1, "adc1"),
+	SARADC_CHANNEL(2, "adc2"),
+	SARADC_CHANNEL(3, "adc3"),
+	SARADC_CHANNEL(4, "adc4"),
+	SARADC_CHANNEL(5, "adc5"),
 };
 
 static const struct rockchip_saradc_data rk3399_saradc_data = {
-- 
2.25.1

Re: [PATCH v5 2/3] iio: adc: rockchip_saradc: better prefix for channel constant

[Jonathan Cameron]

On Sun, 19 Apr 2020 12:02:06 +0200
Heiko Stuebner <heiko@sntech.de> wrote:

> From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> 
> As suggested give the current ADC_CHANNEL constant a distinct
> and consistent prefix.
> 
> Suggested-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Good change. I'll pick up once the rest of the series is ready.

Jonathan

> ---
> changes in v5:
> - new patch
> 
>  drivers/iio/adc/rockchip_saradc.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index 270eb7e83823..29d7f6e4057e 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -118,7 +118,7 @@ static const struct iio_info rockchip_saradc_iio_info = {
>  	.read_raw = rockchip_saradc_read_raw,
>  };
>  
> -#define ADC_CHANNEL(_index, _id) {				\
> +#define SARADC_CHANNEL(_index, _id) {				\
>  	.type = IIO_VOLTAGE,					\
>  	.indexed = 1,						\
>  	.channel = _index,					\
> @@ -128,9 +128,9 @@ static const struct iio_info rockchip_saradc_iio_info = {
>  }
>  
>  static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> -	ADC_CHANNEL(2, "adc2"),
> +	SARADC_CHANNEL(0, "adc0"),
> +	SARADC_CHANNEL(1, "adc1"),
> +	SARADC_CHANNEL(2, "adc2"),
>  };
>  
>  static const struct rockchip_saradc_data saradc_data = {
> @@ -141,8 +141,8 @@ static const struct rockchip_saradc_data saradc_data = {
>  };
>  
>  static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> +	SARADC_CHANNEL(0, "adc0"),
> +	SARADC_CHANNEL(1, "adc1"),
>  };
>  
>  static const struct rockchip_saradc_data rk3066_tsadc_data = {
> @@ -153,12 +153,12 @@ static const struct rockchip_saradc_data rk3066_tsadc_data = {
>  };
>  
>  static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> -	ADC_CHANNEL(2, "adc2"),
> -	ADC_CHANNEL(3, "adc3"),
> -	ADC_CHANNEL(4, "adc4"),
> -	ADC_CHANNEL(5, "adc5"),
> +	SARADC_CHANNEL(0, "adc0"),
> +	SARADC_CHANNEL(1, "adc1"),
> +	SARADC_CHANNEL(2, "adc2"),
> +	SARADC_CHANNEL(3, "adc3"),
> +	SARADC_CHANNEL(4, "adc4"),
> +	SARADC_CHANNEL(5, "adc5"),
>  };
>  
>  static const struct rockchip_saradc_data rk3399_saradc_data = {

[PATCH v5 3/3] iio: adc: rockchip_saradc: Add support iio buffers

[Heiko Stuebner]

From: Simon Xue <xxm@rock-chips.com>

Add the ability to also support access via (triggered) buffers
next to the existing direct mode.

Device in question is the Odroid Go Advance that connects a joystick
to two of the saradc channels for X and Y axis and the new (and still
pending) adc joystick driver of course wants to use triggered buffers
from the iio subsystem.

Signed-off-by: Simon Xue <xxm@rock-chips.com>
[some simplifications and added commit description]
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
changes in v5:
- use IIO_CPU instead of IIO_LE as suggested by Peter
changes in v4:
- comment for the channel-num sanity check in probe
- move to struct for data+timestamp, that way we get the 8-byte
  alignment automatically - checked by comparing sizeof results
changes in v3:
- split buffer struct into values and timestamp area similar to dln2-adc
  and make sure timestamp gets 8-byte aligned - ALIGN uses 4 as it aligns
  u16 elements not bytes - hopefully I got it right this time ;-)
changes in v2:
- use devm_iio_triggered_buffer_setup
- calculate data array size from channel number (curtesy of at91-sama5d2_adc)

 drivers/iio/adc/Kconfig           |   2 +
 drivers/iio/adc/rockchip_saradc.c | 149 ++++++++++++++++++++++--------
 2 files changed, 115 insertions(+), 36 deletions(-)

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 12bb8b7ca1ff..8d2dd60614c6 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -809,6 +809,8 @@ config ROCKCHIP_SARADC
 	tristate "Rockchip SARADC driver"
 	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
 	depends on RESET_CONTROLLER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for the SARADC found in SoCs from
 	  Rockchip.
diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
index 29d7f6e4057e..bdb23088e046 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -15,7 +15,11 @@
 #include <linux/delay.h>
 #include <linux/reset.h>
 #include <linux/regulator/consumer.h>
+#include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #define SARADC_DATA			0x00
 
@@ -32,9 +36,9 @@
 #define SARADC_DLY_PU_SOC_MASK		0x3f
 
 #define SARADC_TIMEOUT			msecs_to_jiffies(100)
+#define SARADC_MAX_CHANNELS		6
 
 struct rockchip_saradc_data {
-	int				num_bits;
 	const struct iio_chan_spec	*channels;
 	int				num_channels;
 	unsigned long			clk_rate;
@@ -49,8 +53,37 @@ struct rockchip_saradc {
 	struct reset_control	*reset;
 	const struct rockchip_saradc_data *data;
 	u16			last_val;
+	const struct iio_chan_spec *last_chan;
 };
 
+static void rockchip_saradc_power_down(struct rockchip_saradc *info)
+{
+	/* Clear irq & power down adc */
+	writel_relaxed(0, info->regs + SARADC_CTRL);
+}
+
+static int rockchip_saradc_conversion(struct rockchip_saradc *info,
+				   struct iio_chan_spec const *chan)
+{
+	reinit_completion(&info->completion);
+
+	/* 8 clock periods as delay between power up and start cmd */
+	writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
+
+	info->last_chan = chan;
+
+	/* Select the channel to be used and trigger conversion */
+	writel(SARADC_CTRL_POWER_CTRL
+			| (chan->channel & SARADC_CTRL_CHN_MASK)
+			| SARADC_CTRL_IRQ_ENABLE,
+		   info->regs + SARADC_CTRL);
+
+	if (!wait_for_completion_timeout(&info->completion, SARADC_TIMEOUT))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
 static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
 				    struct iio_chan_spec const *chan,
 				    int *val, int *val2, long mask)
@@ -62,24 +95,12 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&indio_dev->mlock);
 
-		reinit_completion(&info->completion);
-
-		/* 8 clock periods as delay between power up and start cmd */
-		writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
-
-		/* Select the channel to be used and trigger conversion */
-		writel(SARADC_CTRL_POWER_CTRL
-				| (chan->channel & SARADC_CTRL_CHN_MASK)
-				| SARADC_CTRL_IRQ_ENABLE,
-		       info->regs + SARADC_CTRL);
-
-		if (!wait_for_completion_timeout(&info->completion,
-						 SARADC_TIMEOUT)) {
-			writel_relaxed(0, info->regs + SARADC_CTRL);
+		ret = rockchip_saradc_conversion(info, chan);
+		if (ret) {
+			rockchip_saradc_power_down(info);
 			mutex_unlock(&indio_dev->mlock);
-			return -ETIMEDOUT;
+			return ret;
 		}
-
 		*val = info->last_val;
 		mutex_unlock(&indio_dev->mlock);
 		return IIO_VAL_INT;
@@ -91,7 +112,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
 		}
 
 		*val = ret / 1000;
-		*val2 = info->data->num_bits;
+		*val2 = chan->scan_type.realbits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	default:
 		return -EINVAL;
@@ -104,10 +125,9 @@ static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
 
 	/* Read value */
 	info->last_val = readl_relaxed(info->regs + SARADC_DATA);
-	info->last_val &= GENMASK(info->data->num_bits - 1, 0);
+	info->last_val &= GENMASK(info->last_chan->scan_type.realbits - 1, 0);
 
-	/* Clear irq & power down adc */
-	writel_relaxed(0, info->regs + SARADC_CTRL);
+	rockchip_saradc_power_down(info);
 
 	complete(&info->completion);
 
@@ -118,51 +138,55 @@ static const struct iio_info rockchip_saradc_iio_info = {
 	.read_raw = rockchip_saradc_read_raw,
 };
 
-#define SARADC_CHANNEL(_index, _id) {				\
+#define SARADC_CHANNEL(_index, _id, _res) {			\
 	.type = IIO_VOLTAGE,					\
 	.indexed = 1,						\
 	.channel = _index,					\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 	.datasheet_name = _id,					\
+	.scan_index = _index,					\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = _res,				\
+		.storagebits = 16,				\
+		.endianness = IIO_CPU,				\
+	},							\
 }
 
 static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
-	SARADC_CHANNEL(0, "adc0"),
-	SARADC_CHANNEL(1, "adc1"),
-	SARADC_CHANNEL(2, "adc2"),
+	SARADC_CHANNEL(0, "adc0", 10),
+	SARADC_CHANNEL(1, "adc1", 10),
+	SARADC_CHANNEL(2, "adc2", 10),
 };
 
 static const struct rockchip_saradc_data saradc_data = {
-	.num_bits = 10,
 	.channels = rockchip_saradc_iio_channels,
 	.num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
 	.clk_rate = 1000000,
 };
 
 static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
-	SARADC_CHANNEL(0, "adc0"),
-	SARADC_CHANNEL(1, "adc1"),
+	SARADC_CHANNEL(0, "adc0", 12),
+	SARADC_CHANNEL(1, "adc1", 12),
 };
 
 static const struct rockchip_saradc_data rk3066_tsadc_data = {
-	.num_bits = 12,
 	.channels = rockchip_rk3066_tsadc_iio_channels,
 	.num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
 	.clk_rate = 50000,
 };
 
 static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
-	SARADC_CHANNEL(0, "adc0"),
-	SARADC_CHANNEL(1, "adc1"),
-	SARADC_CHANNEL(2, "adc2"),
-	SARADC_CHANNEL(3, "adc3"),
-	SARADC_CHANNEL(4, "adc4"),
-	SARADC_CHANNEL(5, "adc5"),
+	SARADC_CHANNEL(0, "adc0", 10),
+	SARADC_CHANNEL(1, "adc1", 10),
+	SARADC_CHANNEL(2, "adc2", 10),
+	SARADC_CHANNEL(3, "adc3", 10),
+	SARADC_CHANNEL(4, "adc4", 10),
+	SARADC_CHANNEL(5, "adc5", 10),
 };
 
 static const struct rockchip_saradc_data rk3399_saradc_data = {
-	.num_bits = 10,
 	.channels = rockchip_rk3399_saradc_iio_channels,
 	.num_channels = ARRAY_SIZE(rockchip_rk3399_saradc_iio_channels),
 	.clk_rate = 1000000,
@@ -202,6 +226,47 @@ static void rockchip_saradc_disable(void *data)
 	regulator_disable(info->vref);
 }
 
+static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *i_dev = pf->indio_dev;
+	struct rockchip_saradc *info = iio_priv(i_dev);
+	/*
+	 * @values: each channel takes an u16 value
+	 * @timestamp: will be 8-byte aligned automatically
+	 */
+	struct {
+		u16 values[SARADC_MAX_CHANNELS];
+		int64_t timestamp;
+	} data;
+	int ret;
+	int i, j = 0;
+
+	mutex_lock(&i_dev->mlock);
+
+	for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
+		const struct iio_chan_spec *chan = &i_dev->channels[i];
+
+		ret = rockchip_saradc_conversion(info, chan);
+		if (ret) {
+			rockchip_saradc_power_down(info);
+			goto out;
+		}
+
+		data.values[j] = info->last_val;
+		j++;
+	}
+
+	iio_push_to_buffers_with_timestamp(i_dev, &data,
+					   iio_get_time_ns(i_dev));
+out:
+	mutex_unlock(&i_dev->mlock);
+
+	iio_trigger_notify_done(i_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static int rockchip_saradc_probe(struct platform_device *pdev)
 {
 	struct rockchip_saradc *info = NULL;
@@ -230,6 +295,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 
 	info->data = match->data;
 
+	/* Sanity check for possible later IP variants with more channels */
+	if (info->data->num_channels > SARADC_MAX_CHANNELS) {
+		dev_err(&pdev->dev, "max channels exceeded");
+		return -EINVAL;
+	}
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	info->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(info->regs))
@@ -332,6 +403,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
 	indio_dev->channels = info->data->channels;
 	indio_dev->num_channels = info->data->num_channels;
 
+	ret = devm_iio_triggered_buffer_setup(&indio_dev->dev, indio_dev, NULL,
+					      rockchip_saradc_trigger_handler,
+					      NULL);
+	if (ret)
+		return ret;
+
 	ret = devm_iio_device_register(&pdev->dev, indio_dev);
 	if (ret)
 		return ret;
-- 
2.25.1

Re: [PATCH v5 3/3] iio: adc: rockchip_saradc: Add support iio buffers

[Jonathan Cameron]

On Sun, 19 Apr 2020 12:02:07 +0200
Heiko Stuebner <heiko@sntech.de> wrote:

> From: Simon Xue <xxm@rock-chips.com>
> 
> Add the ability to also support access via (triggered) buffers
> next to the existing direct mode.
> 
> Device in question is the Odroid Go Advance that connects a joystick
> to two of the saradc channels for X and Y axis and the new (and still
> pending) adc joystick driver of course wants to use triggered buffers
> from the iio subsystem.
> 
> Signed-off-by: Simon Xue <xxm@rock-chips.com>
> [some simplifications and added commit description]
> Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
I think you have one unneeded header. Otherwise looks good to me.

Thanks,

Jonathan

> ---
> changes in v5:
> - use IIO_CPU instead of IIO_LE as suggested by Peter
> changes in v4:
> - comment for the channel-num sanity check in probe
> - move to struct for data+timestamp, that way we get the 8-byte
>   alignment automatically - checked by comparing sizeof results
> changes in v3:
> - split buffer struct into values and timestamp area similar to dln2-adc
>   and make sure timestamp gets 8-byte aligned - ALIGN uses 4 as it aligns
>   u16 elements not bytes - hopefully I got it right this time ;-)
> changes in v2:
> - use devm_iio_triggered_buffer_setup
> - calculate data array size from channel number (curtesy of at91-sama5d2_adc)
> 
>  drivers/iio/adc/Kconfig           |   2 +
>  drivers/iio/adc/rockchip_saradc.c | 149 ++++++++++++++++++++++--------
>  2 files changed, 115 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 12bb8b7ca1ff..8d2dd60614c6 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -809,6 +809,8 @@ config ROCKCHIP_SARADC
>  	tristate "Rockchip SARADC driver"
>  	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
>  	depends on RESET_CONTROLLER
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
>  	help
>  	  Say yes here to build support for the SARADC found in SoCs from
>  	  Rockchip.
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index 29d7f6e4057e..bdb23088e046 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -15,7 +15,11 @@
>  #include <linux/delay.h>
>  #include <linux/reset.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/iio/buffer.h>
>  #include <linux/iio/iio.h>
> +#include <linux/iio/trigger.h>

I don't think you need to include trigger.h as that's for drivers providing
a trigger and this one doesn't that I can see...

> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>  
>  #define SARADC_DATA			0x00
>  
> @@ -32,9 +36,9 @@
>  #define SARADC_DLY_PU_SOC_MASK		0x3f
>  
>  #define SARADC_TIMEOUT			msecs_to_jiffies(100)
> +#define SARADC_MAX_CHANNELS		6
>  
>  struct rockchip_saradc_data {
> -	int				num_bits;
>  	const struct iio_chan_spec	*channels;
>  	int				num_channels;
>  	unsigned long			clk_rate;
> @@ -49,8 +53,37 @@ struct rockchip_saradc {
>  	struct reset_control	*reset;
>  	const struct rockchip_saradc_data *data;
>  	u16			last_val;
> +	const struct iio_chan_spec *last_chan;
>  };
>  
> +static void rockchip_saradc_power_down(struct rockchip_saradc *info)
> +{
> +	/* Clear irq & power down adc */
> +	writel_relaxed(0, info->regs + SARADC_CTRL);
> +}
> +
> +static int rockchip_saradc_conversion(struct rockchip_saradc *info,
> +				   struct iio_chan_spec const *chan)
> +{
> +	reinit_completion(&info->completion);
> +
> +	/* 8 clock periods as delay between power up and start cmd */
> +	writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
> +
> +	info->last_chan = chan;
> +
> +	/* Select the channel to be used and trigger conversion */
> +	writel(SARADC_CTRL_POWER_CTRL
> +			| (chan->channel & SARADC_CTRL_CHN_MASK)
> +			| SARADC_CTRL_IRQ_ENABLE,
> +		   info->regs + SARADC_CTRL);
> +
> +	if (!wait_for_completion_timeout(&info->completion, SARADC_TIMEOUT))
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
>  static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>  				    struct iio_chan_spec const *chan,
>  				    int *val, int *val2, long mask)
> @@ -62,24 +95,12 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>  	case IIO_CHAN_INFO_RAW:
>  		mutex_lock(&indio_dev->mlock);
>  
> -		reinit_completion(&info->completion);
> -
> -		/* 8 clock periods as delay between power up and start cmd */
> -		writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
> -
> -		/* Select the channel to be used and trigger conversion */
> -		writel(SARADC_CTRL_POWER_CTRL
> -				| (chan->channel & SARADC_CTRL_CHN_MASK)
> -				| SARADC_CTRL_IRQ_ENABLE,
> -		       info->regs + SARADC_CTRL);
> -
> -		if (!wait_for_completion_timeout(&info->completion,
> -						 SARADC_TIMEOUT)) {
> -			writel_relaxed(0, info->regs + SARADC_CTRL);
> +		ret = rockchip_saradc_conversion(info, chan);
> +		if (ret) {
> +			rockchip_saradc_power_down(info);
>  			mutex_unlock(&indio_dev->mlock);
> -			return -ETIMEDOUT;
> +			return ret;
>  		}
> -

nitpick.  don't mess with unrelated white space :)

>  		*val = info->last_val;
>  		mutex_unlock(&indio_dev->mlock);
>  		return IIO_VAL_INT;
> @@ -91,7 +112,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>  		}
>  
>  		*val = ret / 1000;
> -		*val2 = info->data->num_bits;
> +		*val2 = chan->scan_type.realbits;
>  		return IIO_VAL_FRACTIONAL_LOG2;
>  	default:
>  		return -EINVAL;
> @@ -104,10 +125,9 @@ static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
>  
>  	/* Read value */
>  	info->last_val = readl_relaxed(info->regs + SARADC_DATA);
> -	info->last_val &= GENMASK(info->data->num_bits - 1, 0);
> +	info->last_val &= GENMASK(info->last_chan->scan_type.realbits - 1, 0);
>  
> -	/* Clear irq & power down adc */
> -	writel_relaxed(0, info->regs + SARADC_CTRL);
> +	rockchip_saradc_power_down(info);
>  
>  	complete(&info->completion);
>  
> @@ -118,51 +138,55 @@ static const struct iio_info rockchip_saradc_iio_info = {
>  	.read_raw = rockchip_saradc_read_raw,
>  };
>  
> -#define SARADC_CHANNEL(_index, _id) {				\
> +#define SARADC_CHANNEL(_index, _id, _res) {			\
>  	.type = IIO_VOLTAGE,					\
>  	.indexed = 1,						\
>  	.channel = _index,					\
>  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
>  	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
>  	.datasheet_name = _id,					\
> +	.scan_index = _index,					\
> +	.scan_type = {						\
> +		.sign = 'u',					\
> +		.realbits = _res,				\
> +		.storagebits = 16,				\
> +		.endianness = IIO_CPU,				\
> +	},							\
>  }
>  
>  static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
> -	SARADC_CHANNEL(0, "adc0"),
> -	SARADC_CHANNEL(1, "adc1"),
> -	SARADC_CHANNEL(2, "adc2"),
> +	SARADC_CHANNEL(0, "adc0", 10),
> +	SARADC_CHANNEL(1, "adc1", 10),
> +	SARADC_CHANNEL(2, "adc2", 10),
>  };
>  
>  static const struct rockchip_saradc_data saradc_data = {
> -	.num_bits = 10,
>  	.channels = rockchip_saradc_iio_channels,
>  	.num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
>  	.clk_rate = 1000000,
>  };
>  
>  static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
> -	SARADC_CHANNEL(0, "adc0"),
> -	SARADC_CHANNEL(1, "adc1"),
> +	SARADC_CHANNEL(0, "adc0", 12),
> +	SARADC_CHANNEL(1, "adc1", 12),
>  };
>  
>  static const struct rockchip_saradc_data rk3066_tsadc_data = {
> -	.num_bits = 12,
>  	.channels = rockchip_rk3066_tsadc_iio_channels,
>  	.num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
>  	.clk_rate = 50000,
>  };
>  
>  static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
> -	SARADC_CHANNEL(0, "adc0"),
> -	SARADC_CHANNEL(1, "adc1"),
> -	SARADC_CHANNEL(2, "adc2"),
> -	SARADC_CHANNEL(3, "adc3"),
> -	SARADC_CHANNEL(4, "adc4"),
> -	SARADC_CHANNEL(5, "adc5"),
> +	SARADC_CHANNEL(0, "adc0", 10),
> +	SARADC_CHANNEL(1, "adc1", 10),
> +	SARADC_CHANNEL(2, "adc2", 10),
> +	SARADC_CHANNEL(3, "adc3", 10),
> +	SARADC_CHANNEL(4, "adc4", 10),
> +	SARADC_CHANNEL(5, "adc5", 10),
>  };
>  
>  static const struct rockchip_saradc_data rk3399_saradc_data = {
> -	.num_bits = 10,
>  	.channels = rockchip_rk3399_saradc_iio_channels,
>  	.num_channels = ARRAY_SIZE(rockchip_rk3399_saradc_iio_channels),
>  	.clk_rate = 1000000,
> @@ -202,6 +226,47 @@ static void rockchip_saradc_disable(void *data)
>  	regulator_disable(info->vref);
>  }
>  
> +static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *i_dev = pf->indio_dev;
> +	struct rockchip_saradc *info = iio_priv(i_dev);
> +	/*
> +	 * @values: each channel takes an u16 value
> +	 * @timestamp: will be 8-byte aligned automatically
> +	 */
> +	struct {
> +		u16 values[SARADC_MAX_CHANNELS];
> +		int64_t timestamp;
> +	} data;
> +	int ret;
> +	int i, j = 0;
> +
> +	mutex_lock(&i_dev->mlock);
> +
> +	for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
> +		const struct iio_chan_spec *chan = &i_dev->channels[i];
> +
> +		ret = rockchip_saradc_conversion(info, chan);
> +		if (ret) {
> +			rockchip_saradc_power_down(info);
> +			goto out;
> +		}
> +
> +		data.values[j] = info->last_val;
> +		j++;
> +	}
> +
> +	iio_push_to_buffers_with_timestamp(i_dev, &data,
> +					   iio_get_time_ns(i_dev));
> +out:
> +	mutex_unlock(&i_dev->mlock);
> +
> +	iio_trigger_notify_done(i_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int rockchip_saradc_probe(struct platform_device *pdev)
>  {
>  	struct rockchip_saradc *info = NULL;
> @@ -230,6 +295,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  
>  	info->data = match->data;
>  
> +	/* Sanity check for possible later IP variants with more channels */
> +	if (info->data->num_channels > SARADC_MAX_CHANNELS) {
> +		dev_err(&pdev->dev, "max channels exceeded");
> +		return -EINVAL;
> +	}
> +
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	info->regs = devm_ioremap_resource(&pdev->dev, mem);
>  	if (IS_ERR(info->regs))
> @@ -332,6 +403,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  	indio_dev->channels = info->data->channels;
>  	indio_dev->num_channels = info->data->num_channels;
>  
> +	ret = devm_iio_triggered_buffer_setup(&indio_dev->dev, indio_dev, NULL,
> +					      rockchip_saradc_trigger_handler,
> +					      NULL);
> +	if (ret)
> +		return ret;
> +
>  	ret = devm_iio_device_register(&pdev->dev, indio_dev);
>  	if (ret)
>  		return ret;

Re: [PATCH v5 1/3] iio: adc: rockchip_saradc: move all of probe to devm-functions

[Jonathan Cameron]

On Sun, 19 Apr 2020 12:02:05 +0200
Heiko Stuebner <heiko@sntech.de> wrote:

> From: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> 
> Parts of the saradc probe rely on devm functions and later parts do not.
> This makes it more difficult to for example enable triggers via their
> devm-functions and would need more undo-work in remove.
> 
> So to make life easier for the driver, move the rest of probe calls
> also to their devm-equivalents.
> 
> This includes moving the clk- and regulator-disabling to a devm_action
> so that they gets disabled both during remove and in the error case
> in probe, after the action is registered.
> 
> Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
> ---
> changes in v5:
> - none
> changes in v4:
> - new patch as suggested by Jonathan
> 
>  drivers/iio/adc/rockchip_saradc.c | 37 ++++++++++++++++---------------
>  1 file changed, 19 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index 582ba047c4a6..270eb7e83823 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -193,6 +193,15 @@ static void rockchip_saradc_reset_controller(struct reset_control *reset)
>  	reset_control_deassert(reset);
>  }
>  
> +static void rockchip_saradc_disable(void *data)
> +{
> +	struct rockchip_saradc *info = data;
> +
> +	clk_disable_unprepare(info->clk);
> +	clk_disable_unprepare(info->pclk);
> +	regulator_disable(info->vref);

You should do these independently.  If you use
a separate devm_add_action_or_reset you can drop the error handling
in probe because that will all be cleaned up automatically as well.

Right now you have a nasty hybrid of managed and unmanaged needing
manual cleanup in some paths.

It will take a few more lines of code, but it will be a lot easier
to review / maintain.

Jonathan


> +}
> +
>  static int rockchip_saradc_probe(struct platform_device *pdev)
>  {
>  	struct rockchip_saradc *info = NULL;
> @@ -304,6 +313,14 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  		goto err_pclk;
>  	}
>  
> +	ret = devm_add_action_or_reset(&pdev->dev,
> +				       rockchip_saradc_disable, info);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to register devm action, %d\n",
> +			ret);
> +		return ret;
> +	}
> +
>  	platform_set_drvdata(pdev, indio_dev);
>  
>  	indio_dev->name = dev_name(&pdev->dev);
> @@ -315,14 +332,12 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  	indio_dev->channels = info->data->channels;
>  	indio_dev->num_channels = info->data->num_channels;
>  
> -	ret = iio_device_register(indio_dev);
> +	ret = devm_iio_device_register(&pdev->dev, indio_dev);
>  	if (ret)
> -		goto err_clk;
> +		return ret;
>  
>  	return 0;
>  
> -err_clk:
> -	clk_disable_unprepare(info->clk);
>  err_pclk:
>  	clk_disable_unprepare(info->pclk);

>  err_reg_voltage:
> @@ -330,19 +345,6 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int rockchip_saradc_remove(struct platform_device *pdev)
> -{
> -	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> -	struct rockchip_saradc *info = iio_priv(indio_dev);
> -
> -	iio_device_unregister(indio_dev);
> -	clk_disable_unprepare(info->clk);
> -	clk_disable_unprepare(info->pclk);
> -	regulator_disable(info->vref);
> -
> -	return 0;
> -}
> -
>  #ifdef CONFIG_PM_SLEEP
>  static int rockchip_saradc_suspend(struct device *dev)
>  {
> @@ -383,7 +385,6 @@ static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
>  
>  static struct platform_driver rockchip_saradc_driver = {
>  	.probe		= rockchip_saradc_probe,
> -	.remove		= rockchip_saradc_remove,
>  	.driver		= {
>  		.name	= "rockchip-saradc",
>  		.of_match_table = rockchip_saradc_match,