The ROHM BD96801 "scalable PMIC" provides two physical IRQs. The ERRB
handling can in many cases be omitted because it is used to inform fatal
IRQs, which usually kill the power from the SOC.

There may however be use-cases where the SOC has a 'back-up' emergency
power source which allows some very short time of operation to try to
gracefully shut down sensitive hardware. Furthermore, it is possible the
processor controlling the PMIC is not powered by the PMIC. In such cases
handling the ERRB IRQs may be beneficial.

Add support for ERRB IRQs.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---

This patch was part of the:
https://lore.kernel.org/all/cover.1727931468.git.mazziesaccount@gmail.com/
The MFD part was applied by Lee, but I didn't see the regulator part in
MFD or regulator repository. Perhaps it fell through the cracks? I know
we're late in the cycle but I re-spin this now before I forgot... We do
always have the next cycle, right? :)

 drivers/regulator/bd96801-regulator.c | 130 +++++++++++++++++++++++---
 1 file changed, 115 insertions(+), 15 deletions(-)

diff --git a/drivers/regulator/bd96801-regulator.c b/drivers/regulator/bd96801-regulator.c
index 9876cc05867e..3a9d772491a8 100644
--- a/drivers/regulator/bd96801-regulator.c
+++ b/drivers/regulator/bd96801-regulator.c
@@ -5,12 +5,7 @@
 /*
  * This version of the "BD86801 scalable PMIC"'s driver supports only very
  * basic set of the PMIC features. Most notably, there is no support for
- * the ERRB interrupt and the configurations which should be done when the
- * PMIC is in STBY mode.
- *
- * Supporting the ERRB interrupt would require dropping the regmap-IRQ
- * usage or working around (or accepting a presense of) a naming conflict
- * in debugFS IRQs.
+ * the configurations which should be done when the PMIC is in STBY mode.
  *
  * Being able to reliably do the configurations like changing the
  * regulator safety limits (like limits for the over/under -voltages, over
@@ -22,16 +17,14 @@
  * be the need to configure these safety limits. Hence it's not simple to
  * come up with a generic solution.
  *
- * Users who require the ERRB handling and STBY state configurations can
- * have a look at the original RFC:
+ * Users who require the STBY state configurations can have a look at the
+ * original RFC:
  * https://lore.kernel.org/all/cover.1712920132.git.mazziesaccount@gmail.com/
- * which implements a workaround to debugFS naming conflict and some of
- * the safety limit configurations - but leaves the state change handling
- * and synchronization to be implemented.
+ * which implements some of the safety limit configurations - but leaves the
+ * state change handling and synchronization to be implemented.
  *
  * It would be great to hear (and receive a patch!) if you implement the
- * STBY configuration support or a proper fix to the debugFS naming
- * conflict in your downstream driver ;)
+ * STBY configuration support in your downstream driver ;)
  */
 
 #include <linux/cleanup.h>
@@ -728,6 +721,95 @@ static int initialize_pmic_data(struct device *dev,
 	return 0;
 }
 
+static int bd96801_map_event_all(int irq, struct regulator_irq_data *rid,
+			  unsigned long *dev_mask)
+{
+	int i;
+
+	for (i = 0; i < rid->num_states; i++) {
+		rid->states[i].notifs = REGULATOR_EVENT_FAIL;
+		rid->states[i].errors = REGULATOR_ERROR_FAIL;
+		*dev_mask |= BIT(i);
+	}
+
+	return 0;
+}
+
+static int bd96801_rdev_errb_irqs(struct platform_device *pdev,
+				  struct regulator_dev *rdev)
+{
+	int i;
+	void *retp;
+	static const char * const single_out_errb_irqs[] = {
+		"bd96801-%s-pvin-err", "bd96801-%s-ovp-err",
+		"bd96801-%s-uvp-err", "bd96801-%s-shdn-err",
+	};
+
+	for (i = 0; i < ARRAY_SIZE(single_out_errb_irqs); i++) {
+		struct regulator_irq_desc id = {
+			.map_event = bd96801_map_event_all,
+			.irq_off_ms = 1000,
+		};
+		struct regulator_dev *rdev_arr[1];
+		char tmp[255];
+		int irq;
+
+		snprintf(tmp, 255, single_out_errb_irqs[i], rdev->desc->name);
+		tmp[254] = 0;
+		id.name = tmp;
+
+		irq = platform_get_irq_byname(pdev, tmp);
+		if (irq < 0)
+			continue;
+
+		rdev_arr[0] = rdev;
+		retp = devm_regulator_irq_helper(&pdev->dev, &id, irq, 0,
+						 REGULATOR_ERROR_FAIL, NULL,
+						 rdev_arr, 1);
+		if (IS_ERR(retp))
+			return PTR_ERR(retp);
+
+	}
+	return 0;
+}
+
+static int bd96801_global_errb_irqs(struct platform_device *pdev,
+				    struct regulator_dev **rdev, int num_rdev)
+{
+	int i, num_irqs;
+	void *retp;
+	static const char * const global_errb_irqs[] = {
+		"bd96801-otp-err", "bd96801-dbist-err", "bd96801-eep-err",
+		"bd96801-abist-err", "bd96801-prstb-err", "bd96801-drmoserr1",
+		"bd96801-drmoserr2", "bd96801-slave-err", "bd96801-vref-err",
+		"bd96801-tsd", "bd96801-uvlo-err", "bd96801-ovlo-err",
+		"bd96801-osc-err", "bd96801-pon-err", "bd96801-poff-err",
+		"bd96801-cmd-shdn-err", "bd96801-int-shdn-err"
+	};
+
+	num_irqs = ARRAY_SIZE(global_errb_irqs);
+	for (i = 0; i < num_irqs; i++) {
+		int irq;
+		struct regulator_irq_desc id = {
+			.name = global_errb_irqs[i],
+			.map_event = bd96801_map_event_all,
+			.irq_off_ms = 1000,
+		};
+
+		irq = platform_get_irq_byname(pdev, global_errb_irqs[i]);
+		if (irq < 0)
+			continue;
+
+		retp = devm_regulator_irq_helper(&pdev->dev, &id, irq, 0,
+						 REGULATOR_ERROR_FAIL, NULL,
+						  rdev, num_rdev);
+		if (IS_ERR(retp))
+			return PTR_ERR(retp);
+	}
+
+	return 0;
+}
+
 static int bd96801_rdev_intb_irqs(struct platform_device *pdev,
 				  struct bd96801_pmic_data *pdata,
 				  struct bd96801_irqinfo *iinfo,
@@ -783,11 +865,10 @@ static int bd96801_rdev_intb_irqs(struct platform_device *pdev,
 	return 0;
 }
 
-
-
 static int bd96801_probe(struct platform_device *pdev)
 {
 	struct regulator_dev *ldo_errs_rdev_arr[BD96801_NUM_LDOS];
+	struct regulator_dev *all_rdevs[BD96801_NUM_REGULATORS];
 	struct bd96801_regulator_data *rdesc;
 	struct regulator_config config = {};
 	int ldo_errs_arr[BD96801_NUM_LDOS];
@@ -795,6 +876,7 @@ static int bd96801_probe(struct platform_device *pdev)
 	int temp_notif_ldos = 0;
 	struct device *parent;
 	int i, ret;
+	bool use_errb;
 	void *retp;
 
 	parent = pdev->dev.parent;
@@ -819,6 +901,13 @@ static int bd96801_probe(struct platform_device *pdev)
 	config.regmap = pdata->regmap;
 	config.dev = parent;
 
+	ret = of_property_match_string(pdev->dev.parent->of_node,
+				       "interrupt-names", "errb");
+	if (ret < 0)
+		use_errb = false;
+	else
+		use_errb = true;
+
 	ret = bd96801_walk_regulator_dt(&pdev->dev, pdata->regmap, rdesc,
 					BD96801_NUM_REGULATORS);
 	if (ret)
@@ -837,6 +926,7 @@ static int bd96801_probe(struct platform_device *pdev)
 				rdesc[i].desc.name);
 			return PTR_ERR(rdev);
 		}
+		all_rdevs[i] = rdev;
 		/*
 		 * LDOs don't have own temperature monitoring. If temperature
 		 * notification was requested for this LDO from DT then we will
@@ -856,6 +946,12 @@ static int bd96801_probe(struct platform_device *pdev)
 			if (ret)
 				return ret;
 		}
+		/* Register per regulator ERRB notifiers */
+		if (use_errb) {
+			ret = bd96801_rdev_errb_irqs(pdev, rdev);
+			if (ret)
+				return ret;
+		}
 	}
 	if (temp_notif_ldos) {
 		int irq;
@@ -877,6 +973,10 @@ static int bd96801_probe(struct platform_device *pdev)
 			return PTR_ERR(retp);
 	}
 
+	if (use_errb)
+		return bd96801_global_errb_irqs(pdev, all_rdevs,
+						ARRAY_SIZE(all_rdevs));
+
 	return 0;
 }
 

base-commit: 2d5404caa8c7bb5c4e0435f94b28834ae5456623
-- 
2.47.0

On Thu, Nov 14, 2024 at 09:19:59AM +0200, Matti Vaittinen wrote:

> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
> Reviewed-by: Mark Brown <broonie@kernel.org>
> ---
> 
> This patch was part of the:
> https://lore.kernel.org/all/cover.1727931468.git.mazziesaccount@gmail.com/
> The MFD part was applied by Lee, but I didn't see the regulator part in
> MFD or regulator repository. Perhaps it fell through the cracks? I know
> we're late in the cycle but I re-spin this now before I forgot... We do
> always have the next cycle, right? :)

If this is part of a MFD series I'd have expected it to go in with
that...

On 14/11/2024 13:49, Mark Brown wrote:
> On Thu, Nov 14, 2024 at 09:19:59AM +0200, Matti Vaittinen wrote:
> 
>> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
>> Reviewed-by: Mark Brown <broonie@kernel.org>
>> ---
>>
>> This patch was part of the:
>> https://lore.kernel.org/all/cover.1727931468.git.mazziesaccount@gmail.com/
>> The MFD part was applied by Lee, but I didn't see the regulator part in
>> MFD or regulator repository. Perhaps it fell through the cracks? I know
>> we're late in the cycle but I re-spin this now before I forgot... We do
>> always have the next cycle, right? :)
> 
> If this is part of a MFD series I'd have expected it to go in with
> that...

AFAIR, Lee asked if the patches could be taken in separately. I replied 
"yes" - with a very small corner case of someone having the ERRB in 
device-tree already (which could've been a problem if regulator part 
went in and MFD didn't). After this Lee picked only the subset. I 
suppose this evaded your eye :) I know I should've resent this back 
then, but I just forgot to check if you picked this.

I don't see having the MFD part in without the regulators a problem 
(other than missing the ERRB functionality). So, perhaps Mark can pick 
this after v6.13-rc1 is out?

Yours,
	-- Matti