regulator: bd96801: Add ERRB IRQ

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>
Link: https://patch.msgid.link/ZzWkny4lKpY09SX5@mva-rohm
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: M-Vaittinen

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,
@@ -783,18 +865,18 @@ 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];
 	struct bd96801_pmic_data *pdata;
 	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;
 }