[PATCH v3 0/7] iio: adc: palmas_gpadc: add iio events

[PATCH v3 0/7] iio: adc: palmas_gpadc: add iio events

[Patrik Dahlström]

This series is based on linux-next/master [1] and [2].

The palmas gpadc block has support for monitoring up to 2 ADC channels
and issue an interrupt if they reach past a set threshold. This can be
configured statically with device tree today, but it only gets enabled
when reaching sleep mode. Also, it doesn't look like anyone is using it.

Instead of this one special case, change the code so userspace can
configure the ADC channels to their own needs through the iio events
subsystem. The high and low threshold values can be set for every
channel, but only 2 thresholds can be enabled at a time. Trying to
enable more than 2 thresholds will result in an error.

The configured thresholds will wake up the system from sleep mode if
wakeup is enabled in /sys/devices/.../power/wakeup.

The old platform data was removed.

Thresholds, events, and wakeup were tested on omap5-uevm board. It wakes
up from sleep mode when wakeup is enabled and a threshold is passed. A
userspace tool for monitoring events and adjusting thresholds can be
found at [3].

V2 -> V3:
* Rebased to linux-next.
* Avoid reconfiguring events on error and when old == new value.
V1 -> V2:
* Begin by removing adc_wakeupX_data instead of doing it last.
* Split changes in smaller patches

[1] git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
[2] https://lore.kernel.org/linux-iio/20230318163039.56115-1-jic23@kernel.org/
[3] https://github.com/Risca/pyra_vol_mon

Patrik Dahlström (7):
  iio: adc: palmas: remove adc_wakeupX_data
  iio: adc: palmas: replace "wakeup" with "event"
  iio: adc: palmas: use iio_event_direction for threshold polarity
  iio: adc: palmas: move eventX_enable into palmas_adc_event
  iio: adc: palmas: always reset events on unload
  iio: adc: palmas: add support for iio threshold events
  iio: adc: palmas: don't alter event config on suspend/resume

 drivers/iio/adc/palmas_gpadc.c | 559 +++++++++++++++++++++++++++------
 include/linux/mfd/palmas.h     |   8 -
 2 files changed, 464 insertions(+), 103 deletions(-)


base-commit: 8417c8f5007bf4567ccffda850a3157c7d905f67
prerequisite-patch-id: b0418c707db13f514400956596e9ebe91c25bba0
-- 
2.25.1

[PATCH v3 1/7] iio: adc: palmas: remove adc_wakeupX_data

[Patrik Dahlström]

It does not seem to be used by anyone and later patches in this series
are made simpler by first removing this. There is now a lot of dead code
that cannot be reached, until later patches revive it. Arguably, this is
preferred over removing the code only to add it again.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 50 ++++------------------------------
 include/linux/mfd/palmas.h     |  8 ------
 2 files changed, 6 insertions(+), 52 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 2921186458e0..03af6cd73ec8 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -76,6 +76,12 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = {
 	PALMAS_ADC_INFO(IN15, 0, 0, 0, 0, INVALID, INVALID, true),
 };
 
+struct palmas_adc_wakeup_property {
+	int adc_channel_number;
+	int adc_high_threshold;
+	int adc_low_threshold;
+};
+
 /*
  * struct palmas_gpadc - the palmas_gpadc structure
  * @ch0_current:	channel 0 current source setting
@@ -493,11 +499,6 @@ static int palmas_gpadc_get_adc_dt_data(struct platform_device *pdev,
 	return 0;
 }
 
-static void palmas_disable_wakeup(void *dev)
-{
-	device_wakeup_disable(dev);
-}
-
 static int palmas_gpadc_probe(struct platform_device *pdev)
 {
 	struct palmas_gpadc *adc;
@@ -548,36 +549,6 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
 		return dev_err_probe(adc->dev, ret,
 				     "request irq %d failed\n", adc->irq);
 
-	if (gpadc_pdata->adc_wakeup1_data) {
-		memcpy(&adc->wakeup1_data, gpadc_pdata->adc_wakeup1_data,
-			sizeof(adc->wakeup1_data));
-		adc->wakeup1_enable = true;
-		adc->irq_auto_0 =  platform_get_irq(pdev, 1);
-		ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_0,
-						NULL, palmas_gpadc_irq_auto,
-						IRQF_ONESHOT,
-						"palmas-adc-auto-0", adc);
-		if (ret < 0)
-			return dev_err_probe(adc->dev, ret,
-					     "request auto0 irq %d failed\n",
-					     adc->irq_auto_0);
-	}
-
-	if (gpadc_pdata->adc_wakeup2_data) {
-		memcpy(&adc->wakeup2_data, gpadc_pdata->adc_wakeup2_data,
-				sizeof(adc->wakeup2_data));
-		adc->wakeup2_enable = true;
-		adc->irq_auto_1 =  platform_get_irq(pdev, 2);
-		ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_1,
-						NULL, palmas_gpadc_irq_auto,
-						IRQF_ONESHOT,
-						"palmas-adc-auto-1", adc);
-		if (ret < 0)
-			return dev_err_probe(adc->dev, ret,
-					     "request auto1 irq %d failed\n",
-					     adc->irq_auto_1);
-	}
-
 	/* set the current source 0 (value 0/5/15/20 uA => 0..3) */
 	if (gpadc_pdata->ch0_current <= 1)
 		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_0;
@@ -617,15 +588,6 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
 			palmas_gpadc_calibrate(adc, i);
 	}
 
-	if (adc->wakeup1_enable || adc->wakeup2_enable) {
-		device_wakeup_enable(&pdev->dev);
-		ret = devm_add_action_or_reset(&pdev->dev,
-					       palmas_disable_wakeup,
-					       &pdev->dev);
-		if (ret)
-			return ret;
-	}
-
 	return 0;
 }
 
diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
index 117d02708439..eda1ffd99c1a 100644
--- a/include/linux/mfd/palmas.h
+++ b/include/linux/mfd/palmas.h
@@ -128,12 +128,6 @@ struct palmas_pmic_driver_data {
 			    struct regulator_config config);
 };
 
-struct palmas_adc_wakeup_property {
-	int adc_channel_number;
-	int adc_high_threshold;
-	int adc_low_threshold;
-};
-
 struct palmas_gpadc_platform_data {
 	/* Channel 3 current source is only enabled during conversion */
 	int ch3_current;	/* 0: off; 1: 10uA; 2: 400uA; 3: 800 uA */
@@ -152,8 +146,6 @@ struct palmas_gpadc_platform_data {
 	int start_polarity;
 
 	int auto_conversion_period_ms;
-	struct palmas_adc_wakeup_property *adc_wakeup1_data;
-	struct palmas_adc_wakeup_property *adc_wakeup2_data;
 };
 
 struct palmas_reg_init {
-- 
2.25.1

[PATCH v3 2/7] iio: adc: palmas: replace "wakeup" with "event"

[Patrik Dahlström]

The palmas gpadc block has support for monitoring up to 2 ADC channels
and issue an interrupt if they reach past a set threshold. This is
currently used to wake up the system from sleep, but the functionality
is more generic than that. As such, change the naming of functions and
variables to refer to it as events instead, except during suspend and
resume where wakeup still make sense.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 50 +++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 03af6cd73ec8..55fdf59ef711 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -76,7 +76,7 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = {
 	PALMAS_ADC_INFO(IN15, 0, 0, 0, 0, INVALID, INVALID, true),
 };
 
-struct palmas_adc_wakeup_property {
+struct palmas_adc_event {
 	int adc_channel_number;
 	int adc_high_threshold;
 	int adc_low_threshold;
@@ -117,10 +117,10 @@ struct palmas_gpadc {
 	int				irq_auto_1;
 	struct palmas_gpadc_info	*adc_info;
 	struct completion		conv_completion;
-	struct palmas_adc_wakeup_property wakeup1_data;
-	struct palmas_adc_wakeup_property wakeup2_data;
-	bool				wakeup1_enable;
-	bool				wakeup2_enable;
+	struct palmas_adc_event		event0;
+	struct palmas_adc_event		event1;
+	bool				event0_enable;
+	bool				event1_enable;
 	int				auto_conversion_period;
 	struct mutex			lock;
 };
@@ -591,7 +591,7 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int palmas_adc_wakeup_configure(struct palmas_gpadc *adc)
+static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 {
 	int adc_period, conv;
 	int i;
@@ -617,16 +617,16 @@ static int palmas_adc_wakeup_configure(struct palmas_gpadc *adc)
 	}
 
 	conv = 0;
-	if (adc->wakeup1_enable) {
+	if (adc->event0_enable) {
 		int polarity;
 
-		ch0 = adc->wakeup1_data.adc_channel_number;
+		ch0 = adc->event0.adc_channel_number;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN;
-		if (adc->wakeup1_data.adc_high_threshold > 0) {
-			thres = adc->wakeup1_data.adc_high_threshold;
+		if (adc->event0.adc_high_threshold > 0) {
+			thres = adc->event0.adc_high_threshold;
 			polarity = 0;
 		} else {
-			thres = adc->wakeup1_data.adc_low_threshold;
+			thres = adc->event0.adc_low_threshold;
 			polarity = PALMAS_GPADC_THRES_CONV0_MSB_THRES_CONV0_POL;
 		}
 
@@ -648,16 +648,16 @@ static int palmas_adc_wakeup_configure(struct palmas_gpadc *adc)
 		}
 	}
 
-	if (adc->wakeup2_enable) {
+	if (adc->event1_enable) {
 		int polarity;
 
-		ch1 = adc->wakeup2_data.adc_channel_number;
+		ch1 = adc->event1.adc_channel_number;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN;
-		if (adc->wakeup2_data.adc_high_threshold > 0) {
-			thres = adc->wakeup2_data.adc_high_threshold;
+		if (adc->event1.adc_high_threshold > 0) {
+			thres = adc->event1.adc_high_threshold;
 			polarity = 0;
 		} else {
-			thres = adc->wakeup2_data.adc_low_threshold;
+			thres = adc->event1.adc_low_threshold;
 			polarity = PALMAS_GPADC_THRES_CONV1_MSB_THRES_CONV1_POL;
 		}
 
@@ -696,7 +696,7 @@ static int palmas_adc_wakeup_configure(struct palmas_gpadc *adc)
 	return ret;
 }
 
-static int palmas_adc_wakeup_reset(struct palmas_gpadc *adc)
+static int palmas_adc_reset_events(struct palmas_gpadc *adc)
 {
 	int ret;
 
@@ -718,20 +718,20 @@ static int palmas_gpadc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->wakeup1_enable || adc->wakeup2_enable;
+	int wakeup = adc->event0_enable || adc->event1_enable;
 	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
 		return 0;
 
-	ret = palmas_adc_wakeup_configure(adc);
+	ret = palmas_adc_configure_events(adc);
 	if (ret < 0)
 		return ret;
 
-	if (adc->wakeup1_enable)
+	if (adc->event0_enable)
 		enable_irq_wake(adc->irq_auto_0);
 
-	if (adc->wakeup2_enable)
+	if (adc->event1_enable)
 		enable_irq_wake(adc->irq_auto_1);
 
 	return 0;
@@ -741,20 +741,20 @@ static int palmas_gpadc_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->wakeup1_enable || adc->wakeup2_enable;
+	int wakeup = adc->event0_enable || adc->event1_enable;
 	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
 		return 0;
 
-	ret = palmas_adc_wakeup_reset(adc);
+	ret = palmas_adc_reset_events(adc);
 	if (ret < 0)
 		return ret;
 
-	if (adc->wakeup1_enable)
+	if (adc->event0_enable)
 		disable_irq_wake(adc->irq_auto_0);
 
-	if (adc->wakeup2_enable)
+	if (adc->event1_enable)
 		disable_irq_wake(adc->irq_auto_1);
 
 	return 0;
-- 
2.25.1

[PATCH v3 3/7] iio: adc: palmas: use iio_event_direction for threshold polarity

[Patrik Dahlström]

Instead of having high_threshold > 0 as an indicator for upper threshold
event and lower threshold event otherwise, use enum iio_event_direction
instead. This is hopefully less ambiguous.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 36 ++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 55fdf59ef711..205a7628b235 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -77,9 +77,9 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = {
 };
 
 struct palmas_adc_event {
-	int adc_channel_number;
-	int adc_high_threshold;
-	int adc_low_threshold;
+	int channel;
+	int raw_thresh;
+	enum iio_event_direction direction;
 };
 
 /*
@@ -618,16 +618,21 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 
 	conv = 0;
 	if (adc->event0_enable) {
+		struct palmas_adc_event *ev = &adc->event0;
 		int polarity;
 
-		ch0 = adc->event0.adc_channel_number;
+		ch0 = ev->channel;
+		thres = ev->raw_thresh;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN;
-		if (adc->event0.adc_high_threshold > 0) {
-			thres = adc->event0.adc_high_threshold;
+		switch (ev->direction) {
+		case IIO_EV_DIR_RISING:
 			polarity = 0;
-		} else {
-			thres = adc->event0.adc_low_threshold;
+			break;
+		case IIO_EV_DIR_FALLING:
 			polarity = PALMAS_GPADC_THRES_CONV0_MSB_THRES_CONV0_POL;
+			break;
+		default:
+			return -EINVAL;
 		}
 
 		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
@@ -649,16 +654,21 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 	}
 
 	if (adc->event1_enable) {
+		struct palmas_adc_event *ev = &adc->event1;
 		int polarity;
 
-		ch1 = adc->event1.adc_channel_number;
+		ch1 = ev->channel;
+		thres = ev->raw_thresh;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN;
-		if (adc->event1.adc_high_threshold > 0) {
-			thres = adc->event1.adc_high_threshold;
+		switch (ev->direction) {
+		case IIO_EV_DIR_RISING:
 			polarity = 0;
-		} else {
-			thres = adc->event1.adc_low_threshold;
+			break;
+		case IIO_EV_DIR_FALLING:
 			polarity = PALMAS_GPADC_THRES_CONV1_MSB_THRES_CONV1_POL;
+			break;
+		default:
+			return -EINVAL;
 		}
 
 		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
-- 
2.25.1

[PATCH v3 4/7] iio: adc: palmas: move eventX_enable into palmas_adc_event

[Patrik Dahlström]

It just makes more sense to have all information regarding adc events in
one place.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 205a7628b235..8c6ea4a3cd2e 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -77,6 +77,7 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = {
 };
 
 struct palmas_adc_event {
+	bool enabled;
 	int channel;
 	int raw_thresh;
 	enum iio_event_direction direction;
@@ -119,8 +120,6 @@ struct palmas_gpadc {
 	struct completion		conv_completion;
 	struct palmas_adc_event		event0;
 	struct palmas_adc_event		event1;
-	bool				event0_enable;
-	bool				event1_enable;
 	int				auto_conversion_period;
 	struct mutex			lock;
 };
@@ -617,7 +616,7 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 	}
 
 	conv = 0;
-	if (adc->event0_enable) {
+	if (adc->event0.enabled) {
 		struct palmas_adc_event *ev = &adc->event0;
 		int polarity;
 
@@ -653,7 +652,7 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 		}
 	}
 
-	if (adc->event1_enable) {
+	if (adc->event1.enabled) {
 		struct palmas_adc_event *ev = &adc->event1;
 		int polarity;
 
@@ -728,7 +727,7 @@ static int palmas_gpadc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->event0_enable || adc->event1_enable;
+	int wakeup = adc->event0.enabled || adc->event1.enabled;
 	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
@@ -738,10 +737,10 @@ static int palmas_gpadc_suspend(struct device *dev)
 	if (ret < 0)
 		return ret;
 
-	if (adc->event0_enable)
+	if (adc->event0.enabled)
 		enable_irq_wake(adc->irq_auto_0);
 
-	if (adc->event1_enable)
+	if (adc->event1.enabled)
 		enable_irq_wake(adc->irq_auto_1);
 
 	return 0;
@@ -751,7 +750,7 @@ static int palmas_gpadc_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->event0_enable || adc->event1_enable;
+	int wakeup = adc->event0.enabled || adc->event1.enabled;
 	int ret;
 
 	if (!device_may_wakeup(dev) || !wakeup)
@@ -761,10 +760,10 @@ static int palmas_gpadc_resume(struct device *dev)
 	if (ret < 0)
 		return ret;
 
-	if (adc->event0_enable)
+	if (adc->event0.enabled)
 		disable_irq_wake(adc->irq_auto_0);
 
-	if (adc->event1_enable)
+	if (adc->event1.enabled)
 		disable_irq_wake(adc->irq_auto_1);
 
 	return 0;
-- 
2.25.1

[PATCH v3 5/7] iio: adc: palmas: always reset events on unload

[Patrik Dahlström]

This prevents leaving the adc in freerunning mode when removing the
driver.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 8c6ea4a3cd2e..da4908608a27 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -498,6 +498,13 @@ static int palmas_gpadc_get_adc_dt_data(struct platform_device *pdev,
 	return 0;
 }
 
+static void palmas_gpadc_reset(void *data)
+{
+	struct palmas_gpadc *adc = data;
+	if (adc->event0.enabled || adc->event1.enabled)
+		palmas_adc_reset_events(adc);
+}
+
 static int palmas_gpadc_probe(struct platform_device *pdev)
 {
 	struct palmas_gpadc *adc;
@@ -587,6 +594,10 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
 			palmas_gpadc_calibrate(adc, i);
 	}
 
+	ret = devm_add_action(&pdev->dev, palmas_gpadc_reset, adc);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
-- 
2.25.1

[PATCH v3 6/7] iio: adc: palmas: add support for iio threshold events

[Patrik Dahlström]

The palmas gpadc block has support for monitoring up to 2 ADC channels
and issue an interrupt if they reach past a set threshold. This change
hooks into the IIO events system and exposes to userspace the ability to
configure these threshold values for each channel, but only allow up to
2 such thresholds to be enabled at any given time. Trying to enable a
third channel will result in an error.

Userspace is expected to input calibrated, as opposed to raw, values as
threshold. However, it is not enough to do the opposite of what is done
when converting the other way around. To account for tolerances in the
ADC, the calculated raw threshold should be adjusted based on the ADC
specifications for the device. These specifications include the integral
nonlinearity (INL), offset, and gain error. To adjust the high
threshold, use the following equation:

  (calibrated value + INL) * Gain error + offset = maximum value  [1]

Likewise, use the following equation for the low threshold:

  (calibrated value - INL) * Gain error - offset = minimum value

The gain error is a combination of gain error, as listed in the
datasheet, and gain error drift due to temperature and supply. The exact
values for these specifications vary between palmas devices. This patch
sets the values found in TWL6035, TWL6037 datasheet.

[1] TI Application Report, SLIA087A, Guide to Using the GPADC in
    TPS65903x, TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
V2 -> V3: avoid reconfiguring channels on error and when old == new.

 drivers/iio/adc/palmas_gpadc.c | 447 +++++++++++++++++++++++++++++++--
 1 file changed, 423 insertions(+), 24 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index da4908608a27..2e0755e9e3a4 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -20,6 +20,7 @@
 #include <linux/completion.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/machine.h>
 #include <linux/iio/driver.h>
@@ -79,10 +80,14 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = {
 struct palmas_adc_event {
 	bool enabled;
 	int channel;
-	int raw_thresh;
 	enum iio_event_direction direction;
 };
 
+struct palmas_gpadc_thresholds {
+	int high;
+	int low;
+};
+
 /*
  * struct palmas_gpadc - the palmas_gpadc structure
  * @ch0_current:	channel 0 current source setting
@@ -120,10 +125,31 @@ struct palmas_gpadc {
 	struct completion		conv_completion;
 	struct palmas_adc_event		event0;
 	struct palmas_adc_event		event1;
+	struct palmas_gpadc_thresholds	thresholds[PALMAS_ADC_CH_MAX];
 	int				auto_conversion_period;
 	struct mutex			lock;
 };
 
+static struct palmas_adc_event *palmas_gpadc_get_event(struct palmas_gpadc *adc,
+						       int adc_chan,
+						       enum iio_event_direction dir)
+{
+	if (adc_chan == adc->event0.channel && dir == adc->event0.direction)
+		return &adc->event0;
+
+	if (adc_chan == adc->event1.channel && dir == adc->event1.direction)
+		return &adc->event1;
+
+	return NULL;
+}
+
+static bool palmas_gpadc_channel_is_freerunning(struct palmas_gpadc *adc,
+						int adc_chan)
+{
+	return palmas_gpadc_get_event(adc, adc_chan, IIO_EV_DIR_RISING) ||
+		palmas_gpadc_get_event(adc, adc_chan, IIO_EV_DIR_FALLING);
+}
+
 /*
  * GPADC lock issue in AUTO mode.
  * Impact: In AUTO mode, GPADC conversion can be locked after disabling AUTO
@@ -193,11 +219,24 @@ static irqreturn_t palmas_gpadc_irq(int irq, void *data)
 
 static irqreturn_t palmas_gpadc_irq_auto(int irq, void *data)
 {
-	struct palmas_gpadc *adc = data;
+	struct iio_dev *indio_dev = data;
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	struct palmas_adc_event *ev;
 
 	dev_dbg(adc->dev, "Threshold interrupt %d occurs\n", irq);
 	palmas_disable_auto_conversion(adc);
 
+	ev = (irq == adc->irq_auto_0) ? &adc->event0 : &adc->event1;
+	if (ev->channel != -1) {
+		enum iio_event_direction dir;
+		u64 code;
+
+		dir = ev->direction;
+		code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, ev->channel,
+					    IIO_EV_TYPE_THRESH, dir);
+		iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev));
+	}
+
 	return IRQ_HANDLED;
 }
 
@@ -285,6 +324,9 @@ static int palmas_gpadc_read_prepare(struct palmas_gpadc *adc, int adc_chan)
 {
 	int ret;
 
+	if (palmas_gpadc_channel_is_freerunning(adc, adc_chan))
+		return 0; /* ADC already running */
+
 	ret = palmas_gpadc_enable(adc, adc_chan, true);
 	if (ret < 0)
 		return ret;
@@ -344,28 +386,43 @@ static int palmas_gpadc_start_conversion(struct palmas_gpadc *adc, int adc_chan)
 	unsigned int val;
 	int ret;
 
-	init_completion(&adc->conv_completion);
-	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
-				PALMAS_GPADC_SW_SELECT,
-				PALMAS_GPADC_SW_SELECT_SW_START_CONV0,
-				PALMAS_GPADC_SW_SELECT_SW_START_CONV0);
-	if (ret < 0) {
-		dev_err(adc->dev, "SELECT_SW_START write failed: %d\n", ret);
-		return ret;
-	}
+	if (palmas_gpadc_channel_is_freerunning(adc, adc_chan)) {
+		int event = (adc_chan == adc->event0.channel) ? 0 : 1;
+		unsigned int reg = (event == 0) ?
+			PALMAS_GPADC_AUTO_CONV0_LSB :
+			PALMAS_GPADC_AUTO_CONV1_LSB;
 
-	ret = wait_for_completion_timeout(&adc->conv_completion,
-				PALMAS_ADC_CONVERSION_TIMEOUT);
-	if (ret == 0) {
-		dev_err(adc->dev, "conversion not completed\n");
-		return -ETIMEDOUT;
-	}
+		ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE,
+					reg, &val, 2);
+		if (ret < 0) {
+			dev_err(adc->dev, "AUTO_CONV%x_LSB read failed: %d\n",
+				event, ret);
+			return ret;
+		}
+	} else {
+		init_completion(&adc->conv_completion);
+		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+					PALMAS_GPADC_SW_SELECT,
+					PALMAS_GPADC_SW_SELECT_SW_START_CONV0,
+					PALMAS_GPADC_SW_SELECT_SW_START_CONV0);
+		if (ret < 0) {
+			dev_err(adc->dev, "SELECT_SW_START write failed: %d\n", ret);
+			return ret;
+		}
 
-	ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE,
-				PALMAS_GPADC_SW_CONV0_LSB, &val, 2);
-	if (ret < 0) {
-		dev_err(adc->dev, "SW_CONV0_LSB read failed: %d\n", ret);
-		return ret;
+		ret = wait_for_completion_timeout(&adc->conv_completion,
+					PALMAS_ADC_CONVERSION_TIMEOUT);
+		if (ret == 0) {
+			dev_err(adc->dev, "conversion not completed\n");
+			return -ETIMEDOUT;
+		}
+
+		ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE,
+					PALMAS_GPADC_SW_CONV0_LSB, &val, 2);
+		if (ret < 0) {
+			dev_err(adc->dev, "SW_CONV0_LSB read failed: %d\n", ret);
+			return ret;
+		}
 	}
 
 	ret = val & 0xFFF;
@@ -391,6 +448,98 @@ static int palmas_gpadc_get_calibrated_code(struct palmas_gpadc *adc,
 	return val;
 }
 
+/**
+  * The high and low threshold values are calculated based on the advice given
+  * in TI Application Report SLIA087A, "Guide to Using the GPADC in PS65903x,
+  * TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices". This document recommend
+  * taking ADC tolerances into account and is based on the device integral non-
+  * linearity (INL), offset error and gain error:
+  *
+  *   raw high threshold = (ideal threshold + INL) * gain error + offset error
+  *
+  * The gain error include both gain error, as specified in the datasheet, and
+  * the gain error drift. These paramenters vary depending on device and whether
+  * the the channel is calibrated (trimmed) or not.
+  */
+static int palmas_gpadc_threshold_with_tolerance(int val, const int INL,
+						 const int gain_error,
+						 const int offset_error)
+{
+	val = ((val + INL) * (1000 + gain_error)) / 1000 + offset_error;
+
+	return clamp(val, 0, 0xFFF);
+}
+
+/**
+  * The values below are taken from the datasheet of TWL6035, TWL6037.
+  * todo: get max INL, gain error, and offset error from OF.
+  */
+static int palmas_gpadc_get_high_threshold_raw(struct palmas_gpadc *adc,
+					       struct palmas_adc_event *ev)
+{
+	const int adc_chan = ev->channel;
+	int val = adc->thresholds[adc_chan].high;
+	/* integral nonlinearity, measured in LSB */
+	const int max_INL = 2;
+	/* measured in LSB */
+	int max_offset_error;
+	/* 0.2% when calibrated */
+	int max_gain_error = 2;
+
+	val = (val * 1000) / adc->adc_info[adc_chan].gain;
+
+	if (adc->adc_info[adc_chan].is_uncalibrated) {
+		/* 2% worse */
+		max_gain_error += 20;
+		max_offset_error = 36;
+	} else {
+		val = (val * adc->adc_info[adc_chan].gain_error +
+		       adc->adc_info[adc_chan].offset) /
+			1000;
+		max_offset_error = 2;
+	}
+
+	return palmas_gpadc_threshold_with_tolerance(val,
+						     max_INL,
+						     max_gain_error,
+						     max_offset_error);
+}
+
+/**
+  * The values below are taken from the datasheet of TWL6035, TWL6037.
+  * todo: get min INL, gain error, and offset error from OF.
+  */
+static int palmas_gpadc_get_low_threshold_raw(struct palmas_gpadc *adc,
+					      struct palmas_adc_event *ev)
+{
+	const int adc_chan = ev->channel;
+	int val = adc->thresholds[adc_chan].low;
+	/* integral nonlinearity, measured in LSB */
+	const int min_INL = -2;
+	/* measured in LSB */
+	int min_offset_error;
+	/* -0.6% when calibrated */
+	int min_gain_error = -6;
+
+	val = (val * 1000) / adc->adc_info[adc_chan].gain;
+
+        if (adc->adc_info[adc_chan].is_uncalibrated) {
+		/* 2% worse */
+		min_gain_error -= 20;
+		min_offset_error = -36;
+        } else {
+		val = (val * adc->adc_info[adc_chan].gain_error -
+		       adc->adc_info[adc_chan].offset) /
+			1000;
+		min_offset_error = -2;
+        }
+
+	return palmas_gpadc_threshold_with_tolerance(val,
+						     min_INL,
+						     min_gain_error,
+						     min_offset_error);
+}
+
 static int palmas_gpadc_read_raw(struct iio_dev *indio_dev,
 	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
 {
@@ -437,8 +586,221 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
+static int palmas_gpadc_read_event_config(struct iio_dev *indio_dev,
+					  const struct iio_chan_spec *chan,
+					  enum iio_event_type type,
+					  enum iio_event_direction dir)
+{
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int adc_chan = chan->channel;
+	int ret = 0;
+
+	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	mutex_lock(&adc->lock);
+
+	if (palmas_gpadc_get_event(adc, adc_chan, dir)) {
+		ret = 1;
+	}
+
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
+static int palmas_adc_configure_events(struct palmas_gpadc *adc);
+static int palmas_adc_reset_events(struct palmas_gpadc *adc);
+
+static int palmas_gpadc_reconfigure_event_channels(struct palmas_gpadc *adc)
+{
+	return (adc->event0.enabled || adc->event1.enabled) ?
+		palmas_adc_configure_events(adc) :
+		palmas_adc_reset_events(adc);
+}
+
+static int palmas_gpadc_enable_event_config(struct palmas_gpadc *adc,
+					    const struct iio_chan_spec *chan,
+					    enum iio_event_direction dir)
+{
+	struct palmas_adc_event *ev;
+	int adc_chan = chan->channel;
+
+	if (palmas_gpadc_get_event(adc, adc_chan, dir))
+		/* already enabled */
+		return 0;
+
+	if (adc->event0.channel == -1) {
+		ev = &adc->event0;
+	} else if (adc->event1.channel == -1) {
+		/* event0 has to be the lowest channel */
+		if (adc_chan < adc->event0.channel) {
+			adc->event1 = adc->event0;
+			ev = &adc->event0;
+		} else {
+			ev = &adc->event1;
+		}
+	} else { /* both AUTO channels already in use */
+		dev_warn(adc->dev, "event0 - %d, event1 - %d\n",
+			 adc->event0.channel, adc->event1.channel);
+		return -EBUSY;
+	}
+
+	ev->enabled = true;
+	ev->channel = adc_chan;
+	ev->direction = dir;
+
+	return palmas_gpadc_reconfigure_event_channels(adc);
+}
+
+static int palmas_gpadc_disable_event_config(struct palmas_gpadc *adc,
+					     const struct iio_chan_spec *chan,
+					     enum iio_event_direction dir)
+{
+	int adc_chan = chan->channel;
+	struct palmas_adc_event *ev = palmas_gpadc_get_event(adc, adc_chan, dir);
+
+	if (!ev)
+		return 0;
+
+	if (ev == &adc->event0) {
+		adc->event0 = adc->event1;
+		ev = &adc->event1;
+	}
+
+	ev->enabled = false;
+	ev->channel = -1;
+	ev->direction = IIO_EV_DIR_NONE;
+
+	return palmas_gpadc_reconfigure_event_channels(adc);
+}
+
+static int palmas_gpadc_write_event_config(struct iio_dev *indio_dev,
+					   const struct iio_chan_spec *chan,
+					   enum iio_event_type type,
+					   enum iio_event_direction dir,
+					   int state)
+{
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int adc_chan = chan->channel;
+	int ret = 0;
+
+	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	mutex_lock(&adc->lock);
+
+	if (state)
+		ret = palmas_gpadc_enable_event_config(adc, chan, dir);
+	else
+		ret = palmas_gpadc_disable_event_config(adc, chan, dir);
+
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
+static int palmas_gpadc_read_event_value(struct iio_dev *indio_dev,
+					 const struct iio_chan_spec *chan,
+					 enum iio_event_type type,
+					 enum iio_event_direction dir,
+					 enum iio_event_info info,
+					 int *val, int *val2)
+{
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int adc_chan = chan->channel;
+	int ret = 0;
+
+	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	mutex_lock(&adc->lock);
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		*val = (dir == IIO_EV_DIR_RISING) ?
+			adc->thresholds[adc_chan].high :
+			adc->thresholds[adc_chan].low;
+		ret = IIO_VAL_INT;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
+static int palmas_gpadc_write_event_value(struct iio_dev *indio_dev,
+					  const struct iio_chan_spec *chan,
+					  enum iio_event_type type,
+					  enum iio_event_direction dir,
+					  enum iio_event_info info,
+					  int val, int val2)
+{
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int adc_chan = chan->channel;
+	int old;
+	int ret = 0;
+
+	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
+		return -EINVAL;
+
+	mutex_lock(&adc->lock);
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		if (val < 0 || val > 0xFFF) {
+			ret = -EINVAL;
+			break;
+		}
+		if (dir == IIO_EV_DIR_RISING) {
+			old = adc->thresholds[adc_chan].high;
+			adc->thresholds[adc_chan].high = val;
+		}
+		else {
+			old = adc->thresholds[adc_chan].low;
+			adc->thresholds[adc_chan].low = val;
+		}
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret)
+		goto out_unlock;
+
+	if (val != old && palmas_gpadc_get_event(adc, adc_chan, dir))
+		ret = palmas_gpadc_reconfigure_event_channels(adc);
+
+out_unlock:
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
 static const struct iio_info palmas_gpadc_iio_info = {
 	.read_raw = palmas_gpadc_read_raw,
+	.read_event_config = palmas_gpadc_read_event_config,
+	.write_event_config = palmas_gpadc_write_event_config,
+	.read_event_value = palmas_gpadc_read_event_value,
+	.write_event_value = palmas_gpadc_write_event_value,
+};
+
+static const struct iio_event_spec palmas_gpadc_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+				BIT(IIO_EV_INFO_ENABLE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+				BIT(IIO_EV_INFO_ENABLE),
+	},
 };
 
 #define PALMAS_ADC_CHAN_IIO(chan, _type, chan_info)	\
@@ -449,6 +811,8 @@ static const struct iio_info palmas_gpadc_iio_info = {
 			BIT(chan_info),			\
 	.indexed = 1,					\
 	.channel = PALMAS_ADC_CH_##chan,		\
+	.event_spec = palmas_gpadc_events,		\
+	.num_event_specs = ARRAY_SIZE(palmas_gpadc_events)	\
 }
 
 static const struct iio_chan_spec palmas_gpadc_iio_channel[] = {
@@ -555,6 +919,39 @@ static int palmas_gpadc_probe(struct platform_device *pdev)
 		return dev_err_probe(adc->dev, ret,
 				     "request irq %d failed\n", adc->irq);
 
+	adc->irq_auto_0 = platform_get_irq(pdev, 1);
+	if (adc->irq_auto_0 < 0)
+		return dev_err_probe(adc->dev, adc->irq_auto_0,
+				     "get auto0 irq failed\n");
+
+	ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_0, NULL,
+					palmas_gpadc_irq_auto, IRQF_ONESHOT,
+					"palmas-adc-auto-0", indio_dev);
+	if (ret < 0)
+		return dev_err_probe(adc->dev, ret,
+				     "request auto0 irq %d failed\n",
+				     adc->irq_auto_0);
+
+	adc->irq_auto_1 = platform_get_irq(pdev, 2);
+	if (adc->irq_auto_1 < 0)
+		return dev_err_probe(adc->dev, adc->irq_auto_1,
+				     "get auto1 irq failed\n");
+
+	ret = devm_request_threaded_irq(&pdev->dev, adc->irq_auto_1, NULL,
+					palmas_gpadc_irq_auto, IRQF_ONESHOT,
+					"palmas-adc-auto-1", indio_dev);
+	if (ret < 0)
+		return dev_err_probe(adc->dev, ret,
+				     "request auto1 irq %d failed\n",
+				     adc->irq_auto_1);
+
+	adc->event0.enabled = false;
+	adc->event0.channel = -1;
+	adc->event0.direction = IIO_EV_DIR_NONE;
+	adc->event1.enabled = false;
+	adc->event1.channel = -1;
+	adc->event1.direction = IIO_EV_DIR_NONE;
+
 	/* set the current source 0 (value 0/5/15/20 uA => 0..3) */
 	if (gpadc_pdata->ch0_current <= 1)
 		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_0;
@@ -632,13 +1029,14 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 		int polarity;
 
 		ch0 = ev->channel;
-		thres = ev->raw_thresh;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN;
 		switch (ev->direction) {
 		case IIO_EV_DIR_RISING:
+			thres = palmas_gpadc_get_high_threshold_raw(adc, ev);
 			polarity = 0;
 			break;
 		case IIO_EV_DIR_FALLING:
+			thres = palmas_gpadc_get_low_threshold_raw(adc, ev);
 			polarity = PALMAS_GPADC_THRES_CONV0_MSB_THRES_CONV0_POL;
 			break;
 		default:
@@ -668,13 +1066,14 @@ static int palmas_adc_configure_events(struct palmas_gpadc *adc)
 		int polarity;
 
 		ch1 = ev->channel;
-		thres = ev->raw_thresh;
 		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN;
 		switch (ev->direction) {
 		case IIO_EV_DIR_RISING:
+			thres = palmas_gpadc_get_high_threshold_raw(adc, ev);
 			polarity = 0;
 			break;
 		case IIO_EV_DIR_FALLING:
+			thres = palmas_gpadc_get_low_threshold_raw(adc, ev);
 			polarity = PALMAS_GPADC_THRES_CONV1_MSB_THRES_CONV1_POL;
 			break;
 		default:
-- 
2.25.1

[PATCH v3 7/7] iio: adc: palmas: don't alter event config on suspend/resume

[Patrik Dahlström]

The event config is controlled through the IIO events subsystem and
device wakeup is controlled by /sys/devices/.../power/wakeup. Let's keep
those two knobs independent.

Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
---
 drivers/iio/adc/palmas_gpadc.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
index 2e0755e9e3a4..ba3cc0e68197 100644
--- a/drivers/iio/adc/palmas_gpadc.c
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -1137,16 +1137,10 @@ static int palmas_gpadc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->event0.enabled || adc->event1.enabled;
-	int ret;
 
-	if (!device_may_wakeup(dev) || !wakeup)
+	if (!device_may_wakeup(dev))
 		return 0;
 
-	ret = palmas_adc_configure_events(adc);
-	if (ret < 0)
-		return ret;
-
 	if (adc->event0.enabled)
 		enable_irq_wake(adc->irq_auto_0);
 
@@ -1160,16 +1154,10 @@ static int palmas_gpadc_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct palmas_gpadc *adc = iio_priv(indio_dev);
-	int wakeup = adc->event0.enabled || adc->event1.enabled;
-	int ret;
 
-	if (!device_may_wakeup(dev) || !wakeup)
+	if (!device_may_wakeup(dev))
 		return 0;
 
-	ret = palmas_adc_reset_events(adc);
-	if (ret < 0)
-		return ret;
-
 	if (adc->event0.enabled)
 		disable_irq_wake(adc->irq_auto_0);
 
-- 
2.25.1

Re: [PATCH v3 0/7] iio: adc: palmas_gpadc: add iio events

[Jonathan Cameron]

On Wed,  5 Apr 2023 23:22:26 +0200
Patrik Dahlström <risca@dalakolonin.se> wrote:

> This series is based on linux-next/master [1] and [2].
> 
> The palmas gpadc block has support for monitoring up to 2 ADC channels
> and issue an interrupt if they reach past a set threshold. This can be
> configured statically with device tree today, but it only gets enabled
> when reaching sleep mode. Also, it doesn't look like anyone is using it.
> 
> Instead of this one special case, change the code so userspace can
> configure the ADC channels to their own needs through the iio events
> subsystem. The high and low threshold values can be set for every
> channel, but only 2 thresholds can be enabled at a time. Trying to
> enable more than 2 thresholds will result in an error.
> 
> The configured thresholds will wake up the system from sleep mode if
> wakeup is enabled in /sys/devices/.../power/wakeup.
> 
> The old platform data was removed.
> 
> Thresholds, events, and wakeup were tested on omap5-uevm board. It wakes
> up from sleep mode when wakeup is enabled and a threshold is passed. A
> userspace tool for monitoring events and adjusting thresholds can be
> found at [3].
> 
> V2 -> V3:
> * Rebased to linux-next.

As per reply to the earlier thread.  Don't base on linux-next.
It can be very unstable though not so much later in a cycle like this.

If there isn't a lot of churn going on in the driver, fine to base on
previous release kernel or rc1 (good to say if it is an rc1)

If there is churn underway (which is true here) then iio/togreg + extra
patches lists that need to be applied listed in this cover letter.

I'm also fine with you just adding the devm patch to this series as
the first patch.

Jonathan



> * Avoid reconfiguring events on error and when old == new value.
> V1 -> V2:
> * Begin by removing adc_wakeupX_data instead of doing it last.
> * Split changes in smaller patches
> 
> [1] git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> [2] https://lore.kernel.org/linux-iio/20230318163039.56115-1-jic23@kernel.org/
> [3] https://github.com/Risca/pyra_vol_mon
> 
> Patrik Dahlström (7):
>   iio: adc: palmas: remove adc_wakeupX_data
>   iio: adc: palmas: replace "wakeup" with "event"
>   iio: adc: palmas: use iio_event_direction for threshold polarity
>   iio: adc: palmas: move eventX_enable into palmas_adc_event
>   iio: adc: palmas: always reset events on unload
>   iio: adc: palmas: add support for iio threshold events
>   iio: adc: palmas: don't alter event config on suspend/resume
> 
>  drivers/iio/adc/palmas_gpadc.c | 559 +++++++++++++++++++++++++++------
>  include/linux/mfd/palmas.h     |   8 -
>  2 files changed, 464 insertions(+), 103 deletions(-)
> 
> 
> base-commit: 8417c8f5007bf4567ccffda850a3157c7d905f67
> prerequisite-patch-id: b0418c707db13f514400956596e9ebe91c25bba0

Re: [PATCH v3 0/7] iio: adc: palmas_gpadc: add iio events

[Jonathan Cameron]

On Fri, 7 Apr 2023 18:04:35 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Wed,  5 Apr 2023 23:22:26 +0200
> Patrik Dahlström <risca@dalakolonin.se> wrote:
> 
> > This series is based on linux-next/master [1] and [2].
> > 
> > The palmas gpadc block has support for monitoring up to 2 ADC channels
> > and issue an interrupt if they reach past a set threshold. This can be
> > configured statically with device tree today, but it only gets enabled
> > when reaching sleep mode. Also, it doesn't look like anyone is using it.
> > 
> > Instead of this one special case, change the code so userspace can
> > configure the ADC channels to their own needs through the iio events
> > subsystem. The high and low threshold values can be set for every
> > channel, but only 2 thresholds can be enabled at a time. Trying to
> > enable more than 2 thresholds will result in an error.
> > 
> > The configured thresholds will wake up the system from sleep mode if
> > wakeup is enabled in /sys/devices/.../power/wakeup.
> > 
> > The old platform data was removed.
> > 
> > Thresholds, events, and wakeup were tested on omap5-uevm board. It wakes
> > up from sleep mode when wakeup is enabled and a threshold is passed. A
> > userspace tool for monitoring events and adjusting thresholds can be
> > found at [3].
> > 
> > V2 -> V3:
> > * Rebased to linux-next.  
> 
> As per reply to the earlier thread.  Don't base on linux-next.
> It can be very unstable though not so much later in a cycle like this.
> 
> If there isn't a lot of churn going on in the driver, fine to base on
> previous release kernel or rc1 (good to say if it is an rc1)
> 
> If there is churn underway (which is true here) then iio/togreg + extra
> patches lists that need to be applied listed in this cover letter.

Just goes to show I focused on the change log and skipped the rest :)
As you have it here is fine though change log could have mentioned the
extra patch as well even if just "Rebased to linux-next + devm patch."

In this case linux-next is close enough for this driver to the
iio/togreg tree that it doesn't matter that it shouldn't be used as a base
(no impact in this particular case I think).

Anyhow, all good. I noticed I'd misinterpreted what you'd done here
when I saw the context in one of the patches.  oops :)

Jonathan


> 
> I'm also fine with you just adding the devm patch to this series as
> the first patch.
> 
> Jonathan
> 
> 
> 
> > * Avoid reconfiguring events on error and when old == new value.
> > V1 -> V2:
> > * Begin by removing adc_wakeupX_data instead of doing it last.
> > * Split changes in smaller patches
> > 
> > [1] git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > [2] https://lore.kernel.org/linux-iio/20230318163039.56115-1-jic23@kernel.org/
> > [3] https://github.com/Risca/pyra_vol_mon
> > 
> > Patrik Dahlström (7):
> >   iio: adc: palmas: remove adc_wakeupX_data
> >   iio: adc: palmas: replace "wakeup" with "event"
> >   iio: adc: palmas: use iio_event_direction for threshold polarity
> >   iio: adc: palmas: move eventX_enable into palmas_adc_event
> >   iio: adc: palmas: always reset events on unload
> >   iio: adc: palmas: add support for iio threshold events
> >   iio: adc: palmas: don't alter event config on suspend/resume
> > 
> >  drivers/iio/adc/palmas_gpadc.c | 559 +++++++++++++++++++++++++++------
> >  include/linux/mfd/palmas.h     |   8 -
> >  2 files changed, 464 insertions(+), 103 deletions(-)
> > 
> > 
> > base-commit: 8417c8f5007bf4567ccffda850a3157c7d905f67
> > prerequisite-patch-id: b0418c707db13f514400956596e9ebe91c25bba0  
> 

Re: [PATCH v3 6/7] iio: adc: palmas: add support for iio threshold events

[Jonathan Cameron]

On Wed,  5 Apr 2023 23:22:32 +0200
Patrik Dahlström <risca@dalakolonin.se> wrote:

> The palmas gpadc block has support for monitoring up to 2 ADC channels
> and issue an interrupt if they reach past a set threshold. This change
> hooks into the IIO events system and exposes to userspace the ability to
> configure these threshold values for each channel, but only allow up to
> 2 such thresholds to be enabled at any given time. Trying to enable a
> third channel will result in an error.
> 
> Userspace is expected to input calibrated, as opposed to raw, values as
> threshold. However, it is not enough to do the opposite of what is done
> when converting the other way around. To account for tolerances in the
> ADC, the calculated raw threshold should be adjusted based on the ADC
> specifications for the device. These specifications include the integral
> nonlinearity (INL), offset, and gain error. To adjust the high
> threshold, use the following equation:
> 
>   (calibrated value + INL) * Gain error + offset = maximum value  [1]
> 
> Likewise, use the following equation for the low threshold:
> 
>   (calibrated value - INL) * Gain error - offset = minimum value
> 
> The gain error is a combination of gain error, as listed in the
> datasheet, and gain error drift due to temperature and supply. The exact
> values for these specifications vary between palmas devices. This patch
> sets the values found in TWL6035, TWL6037 datasheet.
> 
> [1] TI Application Report, SLIA087A, Guide to Using the GPADC in
>     TPS65903x, TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices.
> 
> Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
Hi Patrik,

A few really trivial formatting things inline. If we don't end up
with a v4 for other reasons I can tidy this stuff up whilst applying.

Jonathan


>  
> +/**

Not kernel-doc so /* only
Even if it were the indent for the following should align the * with the first * not
the second one.

> +  * The high and low threshold values are calculated based on the advice given
> +  * in TI Application Report SLIA087A, "Guide to Using the GPADC in PS65903x,
> +  * TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices". This document recommend
> +  * taking ADC tolerances into account and is based on the device integral non-
> +  * linearity (INL), offset error and gain error:
> +  *
> +  *   raw high threshold = (ideal threshold + INL) * gain error + offset error
> +  *
> +  * The gain error include both gain error, as specified in the datasheet, and
> +  * the gain error drift. These paramenters vary depending on device and whether
> +  * the the channel is calibrated (trimmed) or not.
> +  */
> +static int palmas_gpadc_threshold_with_tolerance(int val, const int INL,
> +						 const int gain_error,
> +						 const int offset_error)
> +{
> +	val = ((val + INL) * (1000 + gain_error)) / 1000 + offset_error;
> +
> +	return clamp(val, 0, 0xFFF);
> +}
> +
> +/**

/*

> +  * The values below are taken from the datasheet of TWL6035, TWL6037.
> +  * todo: get max INL, gain error, and offset error from OF.
> +  */
> +static int palmas_gpadc_get_high_threshold_raw(struct palmas_gpadc *adc,
> +					       struct palmas_adc_event *ev)
> +{
> +	const int adc_chan = ev->channel;
> +	int val = adc->thresholds[adc_chan].high;
> +	/* integral nonlinearity, measured in LSB */
> +	const int max_INL = 2;
> +	/* measured in LSB */
> +	int max_offset_error;
> +	/* 0.2% when calibrated */
> +	int max_gain_error = 2;
> +
> +	val = (val * 1000) / adc->adc_info[adc_chan].gain;
> +
> +	if (adc->adc_info[adc_chan].is_uncalibrated) {
> +		/* 2% worse */
> +		max_gain_error += 20;
> +		max_offset_error = 36;
> +	} else {
> +		val = (val * adc->adc_info[adc_chan].gain_error +
> +		       adc->adc_info[adc_chan].offset) /
> +			1000;
> +		max_offset_error = 2;
> +	}
> +
> +	return palmas_gpadc_threshold_with_tolerance(val,
> +						     max_INL,
> +						     max_gain_error,
> +						     max_offset_error);
> +}
> +
> +/**

This isn't kernel-doc so just /* 

> +  * The values below are taken from the datasheet of TWL6035, TWL6037.
> +  * todo: get min INL, gain error, and offset error from OF.
> +  */
> +static int palmas_gpadc_get_low_threshold_raw(struct palmas_gpadc *adc,
> +					      struct palmas_adc_event *ev)
> +{
> +	const int adc_chan = ev->channel;
> +	int val = adc->thresholds[adc_chan].low;
> +	/* integral nonlinearity, measured in LSB */
> +	const int min_INL = -2;
> +	/* measured in LSB */
> +	int min_offset_error;
> +	/* -0.6% when calibrated */
> +	int min_gain_error = -6;
> +
> +	val = (val * 1000) / adc->adc_info[adc_chan].gain;
> +
> +        if (adc->adc_info[adc_chan].is_uncalibrated) {
> +		/* 2% worse */
> +		min_gain_error -= 20;
> +		min_offset_error = -36;
> +        } else {
> +		val = (val * adc->adc_info[adc_chan].gain_error -
> +		       adc->adc_info[adc_chan].offset) /
> +			1000;
> +		min_offset_error = -2;
> +        }
> +
> +	return palmas_gpadc_threshold_with_tolerance(val,
> +						     min_INL,
> +						     min_gain_error,
> +						     min_offset_error);
> +}
> +
>  static int palmas_gpadc_read_raw(struct iio_dev *indio_dev,
>  	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>  {
> @@ -437,8 +586,221 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev,
>  	return ret;
>  }
>  
> +static int palmas_gpadc_read_event_config(struct iio_dev *indio_dev,
> +					  const struct iio_chan_spec *chan,
> +					  enum iio_event_type type,
> +					  enum iio_event_direction dir)
> +{
> +	struct palmas_gpadc *adc = iio_priv(indio_dev);
> +	int adc_chan = chan->channel;
> +	int ret = 0;
> +
> +	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
> +		return -EINVAL;
> +
> +	mutex_lock(&adc->lock);
> +
> +	if (palmas_gpadc_get_event(adc, adc_chan, dir)) {
> +		ret = 1;

Trivial: No brackets needed here for kernel style.

> +	}
> +
> +	mutex_unlock(&adc->lock);
> +
> +	return ret;
> +}
...

> +static int palmas_gpadc_write_event_config(struct iio_dev *indio_dev,
> +					   const struct iio_chan_spec *chan,
> +					   enum iio_event_type type,
> +					   enum iio_event_direction dir,
> +					   int state)
> +{
> +	struct palmas_gpadc *adc = iio_priv(indio_dev);
> +	int adc_chan = chan->channel;
> +	int ret = 0;

This initial value isn't used so shouldn't be set.
One of the static analysis tools will spot this so if we don't tidy it up
now chances of it getting 'fixed' later is high.  Better to avoid the
overhead of such a patch.

> +
> +	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
> +		return -EINVAL;
> +
> +	mutex_lock(&adc->lock);
> +
> +	if (state)
> +		ret = palmas_gpadc_enable_event_config(adc, chan, dir);
> +	else
> +		ret = palmas_gpadc_disable_event_config(adc, chan, dir);
> +
> +	mutex_unlock(&adc->lock);
> +
> +	return ret;
> +}
> +
> +static int palmas_gpadc_read_event_value(struct iio_dev *indio_dev,
> +					 const struct iio_chan_spec *chan,
> +					 enum iio_event_type type,
> +					 enum iio_event_direction dir,
> +					 enum iio_event_info info,
> +					 int *val, int *val2)
> +{
> +	struct palmas_gpadc *adc = iio_priv(indio_dev);
> +	int adc_chan = chan->channel;
> +	int ret = 0;

Trivial: I can't see a path where this initial value is used so it
shouldn't be initialized here.

> +
> +	if (adc_chan > PALMAS_ADC_CH_MAX || type != IIO_EV_TYPE_THRESH)
> +		return -EINVAL;
> +
> +	mutex_lock(&adc->lock);
> +
> +	switch (info) {
> +	case IIO_EV_INFO_VALUE:
> +		*val = (dir == IIO_EV_DIR_RISING) ?
> +			adc->thresholds[adc_chan].high :
> +			adc->thresholds[adc_chan].low;
> +		ret = IIO_VAL_INT;
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	mutex_unlock(&adc->lock);
> +
> +	return ret;
> +}
> +

Re: [PATCH v3 7/7] iio: adc: palmas: don't alter event config on suspend/resume

[Jonathan Cameron]

On Wed,  5 Apr 2023 23:22:33 +0200
Patrik Dahlström <risca@dalakolonin.se> wrote:

> The event config is controlled through the IIO events subsystem and
> device wakeup is controlled by /sys/devices/.../power/wakeup. Let's keep
> those two knobs independent.
> 
> Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>

Rest of series that I haven't replied to looks fine to me.

Once the fix patch dependency is in the right upstream branch
I'll get this and the devm patch queued up if no other comments come
in.  

> ---
>  drivers/iio/adc/palmas_gpadc.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
> index 2e0755e9e3a4..ba3cc0e68197 100644
> --- a/drivers/iio/adc/palmas_gpadc.c
> +++ b/drivers/iio/adc/palmas_gpadc.c
> @@ -1137,16 +1137,10 @@ static int palmas_gpadc_suspend(struct device *dev)
>  {
>  	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct palmas_gpadc *adc = iio_priv(indio_dev);
> -	int wakeup = adc->event0.enabled || adc->event1.enabled;
> -	int ret;
>  
> -	if (!device_may_wakeup(dev) || !wakeup)
> +	if (!device_may_wakeup(dev))
>  		return 0;
>  
> -	ret = palmas_adc_configure_events(adc);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (adc->event0.enabled)
>  		enable_irq_wake(adc->irq_auto_0);
>  
> @@ -1160,16 +1154,10 @@ static int palmas_gpadc_resume(struct device *dev)
>  {
>  	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct palmas_gpadc *adc = iio_priv(indio_dev);
> -	int wakeup = adc->event0.enabled || adc->event1.enabled;
> -	int ret;
>  
> -	if (!device_may_wakeup(dev) || !wakeup)
> +	if (!device_may_wakeup(dev))
>  		return 0;
>  
> -	ret = palmas_adc_reset_events(adc);
> -	if (ret < 0)
> -		return ret;
> -
>  	if (adc->event0.enabled)
>  		disable_irq_wake(adc->irq_auto_0);
>  

Re: [PATCH v3 0/7] iio: adc: palmas_gpadc: add iio events

[Patrik Dahlström]

On Fri, Apr 07, 2023 at 06:09:41PM +0100, Jonathan Cameron wrote:
> On Fri, 7 Apr 2023 18:04:35 +0100
> Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > On Wed,  5 Apr 2023 23:22:26 +0200
> > Patrik Dahlström <risca@dalakolonin.se> wrote:
> > 
> > > This series is based on linux-next/master [1] and [2].
> > > 
> > > The palmas gpadc block has support for monitoring up to 2 ADC channels
> > > and issue an interrupt if they reach past a set threshold. This can be
> > > configured statically with device tree today, but it only gets enabled
> > > when reaching sleep mode. Also, it doesn't look like anyone is using it.
> > > 
> > > Instead of this one special case, change the code so userspace can
> > > configure the ADC channels to their own needs through the iio events
> > > subsystem. The high and low threshold values can be set for every
> > > channel, but only 2 thresholds can be enabled at a time. Trying to
> > > enable more than 2 thresholds will result in an error.
> > > 
> > > The configured thresholds will wake up the system from sleep mode if
> > > wakeup is enabled in /sys/devices/.../power/wakeup.
> > > 
> > > The old platform data was removed.
> > > 
> > > Thresholds, events, and wakeup were tested on omap5-uevm board. It wakes
> > > up from sleep mode when wakeup is enabled and a threshold is passed. A
> > > userspace tool for monitoring events and adjusting thresholds can be
> > > found at [3].
> > > 
> > > V2 -> V3:
> > > * Rebased to linux-next.  
> > 
> > As per reply to the earlier thread.  Don't base on linux-next.
> > It can be very unstable though not so much later in a cycle like this.
> > 
> > If there isn't a lot of churn going on in the driver, fine to base on
> > previous release kernel or rc1 (good to say if it is an rc1)
> > 
> > If there is churn underway (which is true here) then iio/togreg + extra
> > patches lists that need to be applied listed in this cover letter.
> 
> Just goes to show I focused on the change log and skipped the rest :)
> As you have it here is fine though change log could have mentioned the
> extra patch as well even if just "Rebased to linux-next + devm patch."
> 
> In this case linux-next is close enough for this driver to the
> iio/togreg tree that it doesn't matter that it shouldn't be used as a base
> (no impact in this particular case I think).

I'll rebase to iio/togreg, fix up the cosmetics, and add the devm patch to
the series. Sounds good?

> 
> Anyhow, all good. I noticed I'd misinterpreted what you'd done here
> when I saw the context in one of the patches.  oops :)

No worries, I'm just glad this is progressing :)

> 
> Jonathan
> 
> 
> > 
> > I'm also fine with you just adding the devm patch to this series as
> > the first patch.
> > 
> > Jonathan
> > 
> > 
> > 
> > > * Avoid reconfiguring events on error and when old == new value.
> > > V1 -> V2:
> > > * Begin by removing adc_wakeupX_data instead of doing it last.
> > > * Split changes in smaller patches
> > > 
> > > [1] git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > > [2] https://lore.kernel.org/linux-iio/20230318163039.56115-1-jic23@kernel.org/
> > > [3] https://github.com/Risca/pyra_vol_mon
> > > 
> > > Patrik Dahlström (7):
> > >   iio: adc: palmas: remove adc_wakeupX_data
> > >   iio: adc: palmas: replace "wakeup" with "event"
> > >   iio: adc: palmas: use iio_event_direction for threshold polarity
> > >   iio: adc: palmas: move eventX_enable into palmas_adc_event
> > >   iio: adc: palmas: always reset events on unload
> > >   iio: adc: palmas: add support for iio threshold events
> > >   iio: adc: palmas: don't alter event config on suspend/resume
> > > 
> > >  drivers/iio/adc/palmas_gpadc.c | 559 +++++++++++++++++++++++++++------
> > >  include/linux/mfd/palmas.h     |   8 -
> > >  2 files changed, 464 insertions(+), 103 deletions(-)
> > > 
> > > 
> > > base-commit: 8417c8f5007bf4567ccffda850a3157c7d905f67
> > > prerequisite-patch-id: b0418c707db13f514400956596e9ebe91c25bba0  
> > 
> 

Re: [PATCH v3 6/7] iio: adc: palmas: add support for iio threshold events

[Patrik Dahlström]

On Fri, Apr 07, 2023 at 06:19:47PM +0100, Jonathan Cameron wrote:
> On Wed,  5 Apr 2023 23:22:32 +0200
> Patrik Dahlström <risca@dalakolonin.se> wrote:
> 
> > The palmas gpadc block has support for monitoring up to 2 ADC channels
> > and issue an interrupt if they reach past a set threshold. This change
> > hooks into the IIO events system and exposes to userspace the ability to
> > configure these threshold values for each channel, but only allow up to
> > 2 such thresholds to be enabled at any given time. Trying to enable a
> > third channel will result in an error.
> > 
> > Userspace is expected to input calibrated, as opposed to raw, values as
> > threshold. However, it is not enough to do the opposite of what is done
> > when converting the other way around. To account for tolerances in the
> > ADC, the calculated raw threshold should be adjusted based on the ADC
> > specifications for the device. These specifications include the integral
> > nonlinearity (INL), offset, and gain error. To adjust the high
> > threshold, use the following equation:
> > 
> >   (calibrated value + INL) * Gain error + offset = maximum value  [1]
> > 
> > Likewise, use the following equation for the low threshold:
> > 
> >   (calibrated value - INL) * Gain error - offset = minimum value
> > 
> > The gain error is a combination of gain error, as listed in the
> > datasheet, and gain error drift due to temperature and supply. The exact
> > values for these specifications vary between palmas devices. This patch
> > sets the values found in TWL6035, TWL6037 datasheet.
> > 
> > [1] TI Application Report, SLIA087A, Guide to Using the GPADC in
> >     TPS65903x, TPS65917-Q1, TPS65919-Q1, and TPS65916 Devices.
> > 
> > Signed-off-by: Patrik Dahlström <risca@dalakolonin.se>
> Hi Patrik,
> 
> A few really trivial formatting things inline. If we don't end up
> with a v4 for other reasons I can tidy this stuff up whilst applying.

I'll send in a v4 later today :)

> 
> Jonathan
> 
>