Merge series "Really implement Qualcomm LAB/IBB regulators" from AngeloGioacchino Del Regno <[e-mail]>:

Okay, the title may be a little "aggressive"? However, the qcom-labibb
driver wasn't really .. doing much.
The current form of this driver is only taking care of enabling or
disabling the regulators, which is pretty useless if they were not
pre-set from the bootloader, which sets them only if continuous
splash is enabled.
Moreover, some bootloaders are setting a higher voltage and/or a higher
current limit compared to what's actually required by the attached
hardware (which is, in 99.9% of the cases, a display) and this produces
a higher power consumption, higher heat output and a risk of actually
burning the display if kept up for a very long time: for example, this
is true on at least some Sony Xperia MSM8998 (Yoshino platform) and
especially on some Sony Xperia SDM845 (Tama platform) smartphones.

In any case, the main reason why this change was necessary for us is
that, during the bringup of Sony Xperia MSM8998 phones, we had an issue
with the bootloader not turning on the display and not setting the lab
and ibb regulators before booting the kernel, making it impossible to
powerup the display.

With this said, this patchset enables setting voltage, current limiting,
overcurrent and short-circuit protection.. and others, on the LAB/IBB
regulators.
Each commit in this patch series provides as many informations as
possible about what's going on and testing methodology.

Changes in v4:
- Remove already applied commit
- Add commit to switch to regulator_{list,map}_voltage_linear
which in v3 got squashed in the commit that got removed in v4.

Changes in v3:
- Improved check for PBS disable and short-circuit condition:
during the testing of short-circuit, coincidentally another
register reading zero on the interesting bit was probed,
which didn't trigger a malfunction of the SC logic, but was
also wrong.
After the change, the short-circuit test was re-done in the
same way as described in the commit that is implementing it.
- From Bjorn Andersson review:
- Improved documentation about over-current and short-circuit
protection in the driver
- Improved maintainability of qcom_labibb_sc_recovery_worker()
- Flipped around check for PBS vreg disabled in for loop of
function labibb_sc_err_handler()
- From Mark Brown (forgotten in v2):
- Changed regulator_{list,map}_voltage_linear_range usages to
regulator_{list,map}_voltage_linear (and fixed regulator
descs to reflect the change).

Changes in v2:
- From Mark Brown review:
- Replaced some if branches with switch statements
- Moved irq get and request in probe function
- Changed short conditionals to full ones
- Removed useless check for ocp_irq_requested
- Fixed issues with YAML documentation

AngeloGioacchino Del Regno (7):
regulator: qcom-labibb: Switch voltage ops from linear_range to linear
regulator: qcom-labibb: Implement current limiting
regulator: qcom-labibb: Implement pull-down, softstart, active
discharge
dt-bindings: regulator: qcom-labibb: Document soft start properties
regulator: qcom-labibb: Implement short-circuit and over-current IRQs
dt-bindings: regulator: qcom-labibb: Document SCP/OCP interrupts
arm64: dts: pmi8998: Add the right interrupts for LAB/IBB SCP and OCP

.../regulator/qcom-labibb-regulator.yaml | 30 +-
arch/arm64/boot/dts/qcom/pmi8998.dtsi | 8 +-
drivers/regulator/qcom-labibb-regulator.c | 720 +++++++++++++++++-
3 files changed, 735 insertions(+), 23 deletions(-)

--
2.30.0

Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml

···
     type: object
 
     properties:
+      qcom,soft-start-us:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Regulator soft start time in microseconds.
+        enum: [200, 400, 600, 800]
+        default: 200
 
       interrupts:
-        maxItems: 1
+        minItems: 1
+        maxItems: 2
         description:
-          Short-circuit interrupt for lab.
+          Short-circuit and over-current interrupts for lab.
 
     required:
       - interrupts
···
     type: object
 
     properties:
+      qcom,discharge-resistor-kohms:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Discharge resistor value in KiloOhms.
+        enum: [300, 64, 32, 16]
+        default: 300
 
       interrupts:
-        maxItems: 1
+        minItems: 1
+        maxItems: 2
         description:
-          Short-circuit interrupt for lab.
+          Short-circuit and over-current interrupts for ibb.
 
     required:
       - interrupts
···
       compatible = "qcom,pmi8998-lab-ibb";
 
       lab {
-        interrupts = <0x3 0x0 IRQ_TYPE_EDGE_RISING>;
-        interrupt-names = "sc-err";
+        interrupts = <0x3 0xde 0x1 IRQ_TYPE_EDGE_RISING>,
+                     <0x3 0xde 0x0 IRQ_TYPE_LEVEL_LOW>;
+        interrupt-names = "sc-err", "ocp";
       };
 
       ibb {
-        interrupts = <0x3 0x2 IRQ_TYPE_EDGE_RISING>;
-        interrupt-names = "sc-err";
+        interrupts = <0x3 0xdc 0x2 IRQ_TYPE_EDGE_RISING>,
+                     <0x3 0xdc 0x0 IRQ_TYPE_LEVEL_LOW>;
+        interrupt-names = "sc-err", "ocp";
       };
     };
 

drivers/regulator/qcom-labibb-regulator.c

···
 
 #define PMI8998_LAB_REG_BASE		0xde00
 #define PMI8998_IBB_REG_BASE		0xdc00
+#define PMI8998_IBB_LAB_REG_OFFSET	0x200
 
 #define REG_LABIBB_STATUS1		0x08
+ #define LABIBB_STATUS1_SC_BIT		BIT(6)
+ #define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
+
+#define REG_LABIBB_INT_SET_TYPE		0x11
+#define REG_LABIBB_INT_POLARITY_HIGH	0x12
+#define REG_LABIBB_INT_POLARITY_LOW	0x13
+#define REG_LABIBB_INT_LATCHED_CLR	0x14
+#define REG_LABIBB_INT_EN_SET		0x15
+#define REG_LABIBB_INT_EN_CLR		0x16
+ #define LABIBB_INT_VREG_OK		BIT(0)
+ #define LABIBB_INT_VREG_TYPE_LEVEL	0
 
 #define REG_LABIBB_VOLTAGE		0x41
  #define LABIBB_VOLTAGE_OVERRIDE_EN	BIT(7)
···
  #define IBB_VOLTAGE_SET_MASK		GENMASK(5, 0)
 
 #define REG_LABIBB_ENABLE_CTL		0x46
-#define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
-#define LABIBB_CONTROL_ENABLE		BIT(7)
+ #define LABIBB_CONTROL_ENABLE		BIT(7)
+
+#define REG_LABIBB_PD_CTL		0x47
+ #define LAB_PD_CTL_MASK		GENMASK(1, 0)
+ #define IBB_PD_CTL_MASK		(BIT(0) | BIT(7))
+ #define LAB_PD_CTL_STRONG_PULL		BIT(0)
+ #define IBB_PD_CTL_HALF_STRENGTH	BIT(0)
+ #define IBB_PD_CTL_EN			BIT(7)
+
+#define REG_LABIBB_CURRENT_LIMIT	0x4b
+ #define LAB_CURRENT_LIMIT_MASK		GENMASK(2, 0)
+ #define IBB_CURRENT_LIMIT_MASK		GENMASK(4, 0)
+ #define LAB_CURRENT_LIMIT_OVERRIDE_EN	BIT(3)
+ #define LABIBB_CURRENT_LIMIT_EN	BIT(7)
+
+#define REG_IBB_PWRUP_PWRDN_CTL_1	0x58
+ #define IBB_CTL_1_DISCHARGE_EN		BIT(2)
+
+#define REG_LABIBB_SOFT_START_CTL	0x5f
+#define REG_LABIBB_SEC_ACCESS		0xd0
+ #define LABIBB_SEC_UNLOCK_CODE		0xa5
 
 #define LAB_ENABLE_CTL_MASK		BIT(7)
 #define IBB_ENABLE_CTL_MASK		(BIT(7) | BIT(6))
···
 #define LAB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 2)
 #define IBB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 10)
 #define LABIBB_POLL_ENABLED_TIME	1000
+#define OCP_RECOVERY_INTERVAL_MS	500
+#define SC_RECOVERY_INTERVAL_MS		250
+#define LABIBB_MAX_OCP_COUNT		4
+#define LABIBB_MAX_SC_COUNT		3
+#define LABIBB_MAX_FATAL_COUNT		2
+
+struct labibb_current_limits {
+	u32				uA_min;
+	u32				uA_step;
+	u8				ovr_val;
+};
 
 struct labibb_regulator {
 	struct regulator_desc		desc;
 	struct device			*dev;
 	struct regmap			*regmap;
 	struct regulator_dev		*rdev;
+	struct labibb_current_limits	uA_limits;
+	struct delayed_work		ocp_recovery_work;
+	struct delayed_work		sc_recovery_work;
 	u16				base;
 	u8				type;
+	u8				dischg_sel;
+	u8				soft_start_sel;
+	int				sc_irq;
+	int				sc_count;
+	int				ocp_irq;
+	int				ocp_irq_count;
+	int				fatal_count;
 };
 
 struct labibb_regulator_data {
···
 	const struct regulator_desc	*desc;
 };
 
+static int qcom_labibb_ocp_hw_enable(struct regulator_dev *rdev)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+	int ret;
+
+	/* Clear irq latch status to avoid spurious event */
+	ret = regmap_update_bits(rdev->regmap,
+				 vreg->base + REG_LABIBB_INT_LATCHED_CLR,
+				 LABIBB_INT_VREG_OK, 1);
+	if (ret)
+		return ret;
+
+	/* Enable OCP HW interrupt */
+	return regmap_update_bits(rdev->regmap,
+				  vreg->base + REG_LABIBB_INT_EN_SET,
+				  LABIBB_INT_VREG_OK, 1);
+}
+
+static int qcom_labibb_ocp_hw_disable(struct regulator_dev *rdev)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+
+	return regmap_update_bits(rdev->regmap,
+				  vreg->base + REG_LABIBB_INT_EN_CLR,
+				  LABIBB_INT_VREG_OK, 1);
+}
+
+/**
+ * qcom_labibb_check_ocp_status - Check the Over-Current Protection status
+ * @vreg: Main driver structure
+ *
+ * This function checks the STATUS1 register for the VREG_OK bit: if it is
+ * set, then there is no Over-Current event.
+ *
+ * Returns: Zero if there is no over-current, 1 if in over-current or
+ *          negative number for error
+ */
+static int qcom_labibb_check_ocp_status(struct labibb_regulator *vreg)
+{
+	u32 cur_status;
+	int ret;
+
+	ret = regmap_read(vreg->rdev->regmap, vreg->base + REG_LABIBB_STATUS1,
+			  &cur_status);
+	if (ret)
+		return ret;
+
+	return !(cur_status & LABIBB_STATUS1_VREG_OK_BIT);
+}
+
+/**
+ * qcom_labibb_ocp_recovery_worker - Handle OCP event
+ * @work: OCP work structure
+ *
+ * This is the worker function to handle the Over Current Protection
+ * hardware event; This will check if the hardware is still
+ * signaling an over-current condition and will eventually stop
+ * the regulator if such condition is still signaled after
+ * LABIBB_MAX_OCP_COUNT times.
+ *
+ * If the driver that is consuming the regulator did not take action
+ * for the OCP condition, or the hardware did not stabilize, a cut
+ * of the LAB and IBB regulators will be forced (regulators will be
+ * disabled).
+ *
+ * As last, if the writes to shut down the LAB/IBB regulators fail
+ * for more than LABIBB_MAX_FATAL_COUNT, then a kernel panic will be
+ * triggered, as a last resort to protect the hardware from burning;
+ * this, however, is expected to never happen, but this is kept to
+ * try to further ensure that we protect the hardware at all costs.
+ */
+static void qcom_labibb_ocp_recovery_worker(struct work_struct *work)
+{
+	struct labibb_regulator *vreg;
+	const struct regulator_ops *ops;
+	int ret;
+
+	vreg = container_of(work, struct labibb_regulator,
+			    ocp_recovery_work.work);
+	ops = vreg->rdev->desc->ops;
+
+	if (vreg->ocp_irq_count >= LABIBB_MAX_OCP_COUNT) {
+		/*
+		 * If we tried to disable the regulator multiple times but
+		 * we kept failing, there's only one last hope to save our
+		 * hardware from the death: raise a kernel bug, reboot and
+		 * hope that the bootloader kindly saves us. This, though
+		 * is done only as paranoid checking, because failing the
+		 * regmap write to disable the vreg is almost impossible,
+		 * since we got here after multiple regmap R/W.
+		 */
+		BUG_ON(vreg->fatal_count > LABIBB_MAX_FATAL_COUNT);
+		dev_err(&vreg->rdev->dev, "LABIBB: CRITICAL: Disabling regulator\n");
+
+		/* Disable the regulator immediately to avoid damage */
+		ret = ops->disable(vreg->rdev);
+		if (ret) {
+			vreg->fatal_count++;
+			goto reschedule;
+		}
+		enable_irq(vreg->ocp_irq);
+		vreg->fatal_count = 0;
+		return;
+	}
+
+	ret = qcom_labibb_check_ocp_status(vreg);
+	if (ret != 0) {
+		vreg->ocp_irq_count++;
+		goto reschedule;
+	}
+
+	ret = qcom_labibb_ocp_hw_enable(vreg->rdev);
+	if (ret) {
+		/* We cannot trust it without OCP enabled. */
+		dev_err(vreg->dev, "Cannot enable OCP IRQ\n");
+		vreg->ocp_irq_count++;
+		goto reschedule;
+	}
+
+	enable_irq(vreg->ocp_irq);
+	/* Everything went fine: reset the OCP count! */
+	vreg->ocp_irq_count = 0;
+	return;
+
+reschedule:
+	mod_delayed_work(system_wq, &vreg->ocp_recovery_work,
+			 msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS));
+}
+
+/**
+ * qcom_labibb_ocp_isr - Interrupt routine for OverCurrent Protection
+ * @irq:  Interrupt number
+ * @chip: Main driver structure
+ *
+ * Over Current Protection (OCP) will signal to the client driver
+ * that an over-current event has happened and then will schedule
+ * a recovery worker.
+ *
+ * Disabling and eventually re-enabling the regulator is expected
+ * to be done by the driver, as some hardware may be triggering an
+ * over-current condition only at first initialization or it may
+ * be expected only for a very brief amount of time, after which
+ * the attached hardware may be expected to stabilize its current
+ * draw.
+ *
+ * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
+ */
+static irqreturn_t qcom_labibb_ocp_isr(int irq, void *chip)
+{
+	struct labibb_regulator *vreg = chip;
+	const struct regulator_ops *ops = vreg->rdev->desc->ops;
+	int ret;
+
+	/* If the regulator is not enabled, this is a fake event */
+	if (!ops->is_enabled(vreg->rdev))
+		return 0;
+
+	/* If we tried to recover for too many times it's not getting better */
+	if (vreg->ocp_irq_count > LABIBB_MAX_OCP_COUNT)
+		return IRQ_NONE;
+
+	/*
+	 * If we (unlikely) can't read this register, to prevent hardware
+	 * damage at all costs, we assume that the overcurrent event was
+	 * real; Moreover, if the status register is not signaling OCP,
+	 * it was a spurious event, so it's all ok.
+	 */
+	ret = qcom_labibb_check_ocp_status(vreg);
+	if (ret == 0) {
+		vreg->ocp_irq_count = 0;
+		goto end;
+	}
+	vreg->ocp_irq_count++;
+
+	/*
+	 * Disable the interrupt temporarily, or it will fire continuously;
+	 * we will re-enable it in the recovery worker function.
+	 */
+	disable_irq(irq);
+
+	/* Warn the user for overcurrent */
+	dev_warn(vreg->dev, "Over-Current interrupt fired!\n");
+
+	/* Disable the interrupt to avoid hogging */
+	ret = qcom_labibb_ocp_hw_disable(vreg->rdev);
+	if (ret)
+		goto end;
+
+	/* Signal overcurrent event to drivers */
+	regulator_notifier_call_chain(vreg->rdev,
+				      REGULATOR_EVENT_OVER_CURRENT, NULL);
+
+end:
+	/* Schedule the recovery work */
+	schedule_delayed_work(&vreg->ocp_recovery_work,
+			      msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS));
+	if (ret)
+		return IRQ_NONE;
+
+	return IRQ_HANDLED;
+}
+
+static int qcom_labibb_set_ocp(struct regulator_dev *rdev)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+	char *ocp_irq_name;
+	u32 irq_flags = IRQF_ONESHOT;
+	int irq_trig_low, ret;
+
+	/* If there is no OCP interrupt, there's nothing to set */
+	if (vreg->ocp_irq <= 0)
+		return -EINVAL;
+
+	ocp_irq_name = devm_kasprintf(vreg->dev, GFP_KERNEL, "%s-over-current",
+				      vreg->desc.name);
+	if (!ocp_irq_name)
+		return -ENOMEM;
+
+	/* IRQ polarities - LAB: trigger-low, IBB: trigger-high */
+	switch (vreg->type) {
+	case QCOM_LAB_TYPE:
+		irq_flags |= IRQF_TRIGGER_LOW;
+		irq_trig_low = 1;
+		break;
+	case QCOM_IBB_TYPE:
+		irq_flags |= IRQF_TRIGGER_HIGH;
+		irq_trig_low = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Activate OCP HW level interrupt */
+	ret = regmap_update_bits(rdev->regmap,
+				 vreg->base + REG_LABIBB_INT_SET_TYPE,
+				 LABIBB_INT_VREG_OK,
+				 LABIBB_INT_VREG_TYPE_LEVEL);
+	if (ret)
+		return ret;
+
+	/* Set OCP interrupt polarity */
+	ret = regmap_update_bits(rdev->regmap,
+				 vreg->base + REG_LABIBB_INT_POLARITY_HIGH,
+				 LABIBB_INT_VREG_OK, !irq_trig_low);
+	if (ret)
+		return ret;
+	ret = regmap_update_bits(rdev->regmap,
+				 vreg->base + REG_LABIBB_INT_POLARITY_LOW,
+				 LABIBB_INT_VREG_OK, irq_trig_low);
+	if (ret)
+		return ret;
+
+	ret = qcom_labibb_ocp_hw_enable(rdev);
+	if (ret)
+		return ret;
+
+	return devm_request_threaded_irq(vreg->dev, vreg->ocp_irq, NULL,
+					 qcom_labibb_ocp_isr, irq_flags,
+					 ocp_irq_name, vreg);
+}
+
+/**
+ * qcom_labibb_check_sc_status - Check the Short Circuit Protection status
+ * @vreg: Main driver structure
+ *
+ * This function checks the STATUS1 register on both LAB and IBB regulators
+ * for the ShortCircuit bit: if it is set on *any* of them, then we have
+ * experienced a short-circuit event.
+ *
+ * Returns: Zero if there is no short-circuit, 1 if in short-circuit or
+ *          negative number for error
+ */
+static int qcom_labibb_check_sc_status(struct labibb_regulator *vreg)
+{
+	u32 ibb_status, ibb_reg, lab_status, lab_reg;
+	int ret;
+
+	/* We have to work on both regulators due to PBS... */
+	lab_reg = ibb_reg = vreg->base + REG_LABIBB_STATUS1;
+	if (vreg->type == QCOM_LAB_TYPE)
+		ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET;
+	else
+		lab_reg += PMI8998_IBB_LAB_REG_OFFSET;
+
+	ret = regmap_read(vreg->rdev->regmap, lab_reg, &lab_status);
+	if (ret)
+		return ret;
+	ret = regmap_read(vreg->rdev->regmap, ibb_reg, &ibb_status);
+	if (ret)
+		return ret;
+
+	return !!(lab_status & LABIBB_STATUS1_SC_BIT) ||
+	       !!(ibb_status & LABIBB_STATUS1_SC_BIT);
+}
+
+/**
+ * qcom_labibb_sc_recovery_worker - Handle Short Circuit event
+ * @work: SC work structure
+ *
+ * This is the worker function to handle the Short Circuit Protection
+ * hardware event; This will check if the hardware is still
+ * signaling a short-circuit condition and will eventually never
+ * re-enable the regulator if such condition is still signaled after
+ * LABIBB_MAX_SC_COUNT times.
+ *
+ * If the driver that is consuming the regulator did not take action
+ * for the SC condition, or the hardware did not stabilize, this
+ * worker will stop rescheduling, leaving the regulators disabled
+ * as already done by the Portable Batch System (PBS).
+ *
+ * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
+ */
+static void qcom_labibb_sc_recovery_worker(struct work_struct *work)
+{
+	struct labibb_regulator *vreg;
+	const struct regulator_ops *ops;
+	u32 lab_reg, ibb_reg, lab_val, ibb_val, val;
+	bool pbs_cut = false;
+	int i, sc, ret;
+
+	vreg = container_of(work, struct labibb_regulator,
+			    sc_recovery_work.work);
+	ops = vreg->rdev->desc->ops;
+
+	/*
+	 * If we tried to check the regulator status multiple times but we
+	 * kept failing, then just bail out, as the Portable Batch System
+	 * (PBS) will disable the vregs for us, preventing hardware damage.
+	 */
+	if (vreg->fatal_count > LABIBB_MAX_FATAL_COUNT)
+		return;
+
+	/* Too many short-circuit events. Throw in the towel. */
+	if (vreg->sc_count > LABIBB_MAX_SC_COUNT)
+		return;
+
+	/*
+	 * The Portable Batch System (PBS) automatically disables LAB
+	 * and IBB when a short-circuit event is detected, so we have to
+	 * check and work on both of them at the same time.
+	 */
+	lab_reg = ibb_reg = vreg->base + REG_LABIBB_ENABLE_CTL;
+	if (vreg->type == QCOM_LAB_TYPE)
+		ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET;
+	else
+		lab_reg += PMI8998_IBB_LAB_REG_OFFSET;
+
+	sc = qcom_labibb_check_sc_status(vreg);
+	if (sc)
+		goto reschedule;
+
+	for (i = 0; i < LABIBB_MAX_SC_COUNT; i++) {
+		ret = regmap_read(vreg->regmap, lab_reg, &lab_val);
+		if (ret) {
+			vreg->fatal_count++;
+			goto reschedule;
+		}
+
+		ret = regmap_read(vreg->regmap, ibb_reg, &ibb_val);
+		if (ret) {
+			vreg->fatal_count++;
+			goto reschedule;
+		}
+		val = lab_val & ibb_val;
+
+		if (!(val & LABIBB_CONTROL_ENABLE)) {
+			pbs_cut = true;
+			break;
+		}
+		usleep_range(5000, 6000);
+	}
+	if (pbs_cut)
+		goto reschedule;
+
+
+	/*
+	 * If we have reached this point, we either have successfully
+	 * recovered from the SC condition or we had a spurious SC IRQ,
+	 * which means that we can re-enable the regulators, if they
+	 * have ever been disabled by the PBS.
+	 */
+	ret = ops->enable(vreg->rdev);
+	if (ret)
+		goto reschedule;
+
+	/* Everything went fine: reset the OCP count! */
+	vreg->sc_count = 0;
+	enable_irq(vreg->sc_irq);
+	return;
+
+reschedule:
+	/*
+	 * Now that we have done basic handling of the short-circuit,
+	 * reschedule this worker in the regular system workqueue, as
+	 * taking action is not truly urgent anymore.
+	 */
+	vreg->sc_count++;
+	mod_delayed_work(system_wq, &vreg->sc_recovery_work,
+			 msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS));
+}
+
+/**
+ * qcom_labibb_sc_isr - Interrupt routine for Short Circuit Protection
+ * @irq:  Interrupt number
+ * @chip: Main driver structure
+ *
+ * Short Circuit Protection (SCP) will signal to the client driver
+ * that a regulation-out event has happened and then will schedule
+ * a recovery worker.
+ *
+ * The LAB and IBB regulators will be automatically disabled by the
+ * Portable Batch System (PBS) and they will be enabled again by
+ * the worker function if the hardware stops signaling the short
+ * circuit event.
+ *
+ * Returns: IRQ_HANDLED for success or IRQ_NONE for failure.
+ */
+static irqreturn_t qcom_labibb_sc_isr(int irq, void *chip)
+{
+	struct labibb_regulator *vreg = chip;
+
+	if (vreg->sc_count > LABIBB_MAX_SC_COUNT)
+		return IRQ_NONE;
+
+	/* Warn the user for short circuit */
+	dev_warn(vreg->dev, "Short-Circuit interrupt fired!\n");
+
+	/*
+	 * Disable the interrupt temporarily, or it will fire continuously;
+	 * we will re-enable it in the recovery worker function.
+	 */
+	disable_irq(irq);
+
+	/* Signal out of regulation event to drivers */
+	regulator_notifier_call_chain(vreg->rdev,
+				      REGULATOR_EVENT_REGULATION_OUT, NULL);
+
+	/* Schedule the short-circuit handling as high-priority work */
+	mod_delayed_work(system_highpri_wq, &vreg->sc_recovery_work,
+			 msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS));
+	return IRQ_HANDLED;
+}
+
+
+static int qcom_labibb_set_current_limit(struct regulator_dev *rdev,
+					 int min_uA, int max_uA)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+	struct regulator_desc *desc = &vreg->desc;
+	struct labibb_current_limits *lim = &vreg->uA_limits;
+	u32 mask, val;
+	int i, ret, sel = -1;
+
+	if (min_uA < lim->uA_min || max_uA < lim->uA_min)
+		return -EINVAL;
+
+	for (i = 0; i < desc->n_current_limits; i++) {
+		int uA_limit = (lim->uA_step * i) + lim->uA_min;
+
+		if (max_uA >= uA_limit && min_uA <= uA_limit)
+			sel = i;
+	}
+	if (sel < 0)
+		return -EINVAL;
+
+	/* Current limit setting needs secure access */
+	ret = regmap_write(vreg->regmap, vreg->base + REG_LABIBB_SEC_ACCESS,
+			   LABIBB_SEC_UNLOCK_CODE);
+	if (ret)
+		return ret;
+
+	mask = desc->csel_mask | lim->ovr_val;
+	mask |= LABIBB_CURRENT_LIMIT_EN;
+	val = (u32)sel | lim->ovr_val;
+	val |= LABIBB_CURRENT_LIMIT_EN;
+
+	return regmap_update_bits(vreg->regmap, desc->csel_reg, mask, val);
+}
+
+static int qcom_labibb_get_current_limit(struct regulator_dev *rdev)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+	struct regulator_desc *desc = &vreg->desc;
+	struct labibb_current_limits *lim = &vreg->uA_limits;
+	unsigned int cur_step;
+	int ret;
+
+	ret = regmap_read(vreg->regmap, desc->csel_reg, &cur_step);
+	if (ret)
+		return ret;
+	cur_step &= desc->csel_mask;
+
+	return (cur_step * lim->uA_step) + lim->uA_min;
+}
+
+static int qcom_labibb_set_soft_start(struct regulator_dev *rdev)
+{
+	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+	u32 val = 0;
+
+	if (vreg->type == QCOM_IBB_TYPE)
+		val = vreg->dischg_sel;
+	else
+		val = vreg->soft_start_sel;
+
+	return regmap_write(rdev->regmap, rdev->desc->soft_start_reg, val);
+}
+
+static int qcom_labibb_get_table_sel(const int *table, int sz, u32 value)
+{
+	int i;
+
+	for (i = 0; i < sz; i++)
+		if (table[i] == value)
+			return i;
+	return -EINVAL;
+}
+
+/* IBB discharge resistor values in KOhms */
+static const int dischg_resistor_values[] = { 300, 64, 32, 16 };
+
+/* Soft start time in microseconds */
+static const int soft_start_values[] = { 200, 400, 600, 800 };
+
+static int qcom_labibb_of_parse_cb(struct device_node *np,
+				   const struct regulator_desc *desc,
+				   struct regulator_config *config)
+{
+	struct labibb_regulator *vreg = config->driver_data;
+	u32 dischg_kohms, soft_start_time;
+	int ret;
+
+	ret = of_property_read_u32(np, "qcom,discharge-resistor-kohms",
+				       &dischg_kohms);
+	if (ret)
+		dischg_kohms = 300;
+
+	ret = qcom_labibb_get_table_sel(dischg_resistor_values,
+					ARRAY_SIZE(dischg_resistor_values),
+					dischg_kohms);
+	if (ret < 0)
+		return ret;
+	vreg->dischg_sel = (u8)ret;
+
+	ret = of_property_read_u32(np, "qcom,soft-start-us",
+				   &soft_start_time);
+	if (ret)
+		soft_start_time = 200;
+
+	ret = qcom_labibb_get_table_sel(soft_start_values,
+					ARRAY_SIZE(soft_start_values),
+					soft_start_time);
+	if (ret < 0)
+		return ret;
+	vreg->soft_start_sel = (u8)ret;
+
+	return 0;
+}
+
 static const struct regulator_ops qcom_labibb_ops = {
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,
 	.is_enabled		= regulator_is_enabled_regmap,
 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
-	.list_voltage		= regulator_list_voltage_linear_range,
-	.map_voltage		= regulator_map_voltage_linear_range,
+	.list_voltage		= regulator_list_voltage_linear,
+	.map_voltage		= regulator_map_voltage_linear,
+	.set_active_discharge	= regulator_set_active_discharge_regmap,
+	.set_pull_down		= regulator_set_pull_down_regmap,
+	.set_current_limit	= qcom_labibb_set_current_limit,
+	.get_current_limit	= qcom_labibb_get_current_limit,
+	.set_soft_start		= qcom_labibb_set_soft_start,
+	.set_over_current_protection = qcom_labibb_set_ocp,
 };
 
 static const struct regulator_desc pmi8998_lab_desc = {
···
 	.enable_val		= LABIBB_CONTROL_ENABLE,
 	.enable_time		= LAB_ENABLE_TIME,
 	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
+	.soft_start_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
+	.pull_down_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_PD_CTL),
+	.pull_down_mask		= LAB_PD_CTL_MASK,
+	.pull_down_val_on	= LAB_PD_CTL_STRONG_PULL,
 	.vsel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
 	.vsel_mask		= LAB_VOLTAGE_SET_MASK,
 	.apply_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_VOLTAGE),
 	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
+	.csel_reg		= (PMI8998_LAB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
+	.csel_mask		= LAB_CURRENT_LIMIT_MASK,
+	.n_current_limits	= 8,
 	.off_on_delay		= LABIBB_OFF_ON_DELAY,
 	.owner			= THIS_MODULE,
 	.type			= REGULATOR_VOLTAGE,
-	.linear_ranges		= (struct linear_range[]) {
-		REGULATOR_LINEAR_RANGE(4600000, 0, 15, 100000),
-	},
-	.n_linear_ranges	= 1,
+	.min_uV			= 4600000,
+	.uV_step		= 100000,
 	.n_voltages		= 16,
 	.ops			= &qcom_labibb_ops,
+	.of_parse_cb		= qcom_labibb_of_parse_cb,
 };
 
 static const struct regulator_desc pmi8998_ibb_desc = {
···
 	.enable_val		= LABIBB_CONTROL_ENABLE,
 	.enable_time		= IBB_ENABLE_TIME,
 	.poll_enabled_time	= LABIBB_POLL_ENABLED_TIME,
+	.soft_start_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_SOFT_START_CTL),
+	.active_discharge_off	= 0,
+	.active_discharge_on	= IBB_CTL_1_DISCHARGE_EN,
+	.active_discharge_mask	= IBB_CTL_1_DISCHARGE_EN,
+	.active_discharge_reg	= (PMI8998_IBB_REG_BASE + REG_IBB_PWRUP_PWRDN_CTL_1),
+	.pull_down_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_PD_CTL),
+	.pull_down_mask		= IBB_PD_CTL_MASK,
+	.pull_down_val_on	= IBB_PD_CTL_HALF_STRENGTH | IBB_PD_CTL_EN,
 	.vsel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
 	.vsel_mask		= IBB_VOLTAGE_SET_MASK,
 	.apply_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_VOLTAGE),
 	.apply_bit		= LABIBB_VOLTAGE_OVERRIDE_EN,
+	.csel_reg		= (PMI8998_IBB_REG_BASE + REG_LABIBB_CURRENT_LIMIT),
+	.csel_mask		= IBB_CURRENT_LIMIT_MASK,
+	.n_current_limits	= 32,
 	.off_on_delay		= LABIBB_OFF_ON_DELAY,
 	.owner			= THIS_MODULE,
 	.type			= REGULATOR_VOLTAGE,
-	.linear_ranges		= (struct linear_range[]) {
-		REGULATOR_LINEAR_RANGE(1400000, 0, 63, 100000),
-	},
-	.n_linear_ranges	= 1,
+	.min_uV			= 1400000,
+	.uV_step		= 100000,
 	.n_voltages		= 64,
 	.ops			= &qcom_labibb_ops,
+	.of_parse_cb		= qcom_labibb_of_parse_cb,
 };
 
 static const struct labibb_regulator_data pmi8998_labibb_data[] = {
···
 	struct labibb_regulator *vreg;
 	struct device *dev = &pdev->dev;
 	struct regulator_config cfg = {};
-
+	struct device_node *reg_node;
 	const struct of_device_id *match;
 	const struct labibb_regulator_data *reg_data;
 	struct regmap *reg_regmap;
···
 		return -ENODEV;
 
 	for (reg_data = match->data; reg_data->name; reg_data++) {
+		char *sc_irq_name;
+		int irq = 0;
 
 		/* Validate if the type of regulator is indeed
 		 * what's mentioned in DT.
···
 		if (!vreg)
 			return -ENOMEM;
 
+		sc_irq_name = devm_kasprintf(dev, GFP_KERNEL,
+					     "%s-short-circuit",
+					     reg_data->name);
+		if (!sc_irq_name)
+			return -ENOMEM;
+
+		reg_node = of_get_child_by_name(pdev->dev.of_node,
+						reg_data->name);
+		if (!reg_node)
+			return -EINVAL;
+
+		/* The Short Circuit interrupt is critical */
+		irq = of_irq_get_byname(reg_node, "sc-err");
+		if (irq <= 0) {
+			if (irq == 0)
+				irq = -EINVAL;
+
+			return dev_err_probe(vreg->dev, irq,
+					     "Short-circuit irq not found.\n");
+		}
+		vreg->sc_irq = irq;
+
+		/* OverCurrent Protection IRQ is optional */
+		irq = of_irq_get_byname(reg_node, "ocp");
+		vreg->ocp_irq = irq;
+		vreg->ocp_irq_count = 0;
+		of_node_put(reg_node);
+
 		vreg->regmap = reg_regmap;
 		vreg->dev = dev;
 		vreg->base = reg_data->base;
 		vreg->type = reg_data->type;
+		INIT_DELAYED_WORK(&vreg->sc_recovery_work,
+				  qcom_labibb_sc_recovery_worker);
+
+		if (vreg->ocp_irq > 0)
+			INIT_DELAYED_WORK(&vreg->ocp_recovery_work,
+					  qcom_labibb_ocp_recovery_worker);
+
+		switch (vreg->type) {
+		case QCOM_LAB_TYPE:
+			/* LAB Limits: 200-1600mA */
+			vreg->uA_limits.uA_min  = 200000;
+			vreg->uA_limits.uA_step = 200000;
+			vreg->uA_limits.ovr_val = LAB_CURRENT_LIMIT_OVERRIDE_EN;
+			break;
+		case QCOM_IBB_TYPE:
+			/* IBB Limits: 0-1550mA */
+			vreg->uA_limits.uA_min  = 0;
+			vreg->uA_limits.uA_step = 50000;
+			vreg->uA_limits.ovr_val = 0; /* No override bit */
+			break;
+		default:
+			return -EINVAL;
+		}
 
 		memcpy(&vreg->desc, reg_data->desc, sizeof(vreg->desc));
 		vreg->desc.of_match = reg_data->name;
···
 					reg_data->name, ret);
 			return PTR_ERR(vreg->rdev);
 		}
+
+		ret = devm_request_threaded_irq(vreg->dev, vreg->sc_irq, NULL,
+						qcom_labibb_sc_isr,
+						IRQF_ONESHOT |
+						IRQF_TRIGGER_RISING,
+						sc_irq_name, vreg);
+		if (ret)
+			return ret;
 	}
 
 	return 0;