[PATCH v4 0/7] Really implement Qualcomm LAB/IBB regulators

[PATCH v4 0/7] Really implement Qualcomm LAB/IBB regulators

[AngeloGioacchino Del Regno]

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

[PATCH v4 1/7] regulator: qcom-labibb: Switch voltage ops from linear_range to linear

[AngeloGioacchino Del Regno]

The LAB and IBB regulator have just one range and it is useless
to use linear_range ops, as these are used to express multiple
linear ranges.

Switch list_voltage and map_voltage callbacks to *_linear instead.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
---
 drivers/regulator/qcom-labibb-regulator.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index 9f51c96f16fb..0fe0f6bce4cf 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -59,8 +59,8 @@ static const struct regulator_ops qcom_labibb_ops = {
 	.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,
 };
 
 static const struct regulator_desc pmi8998_lab_desc = {
@@ -76,10 +76,8 @@ static const struct regulator_desc pmi8998_lab_desc = {
 	.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,
 };
@@ -97,10 +95,8 @@ static const struct regulator_desc pmi8998_ibb_desc = {
 	.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,
 };
-- 
2.30.0

[PATCH v4 2/7] regulator: qcom-labibb: Implement current limiting

[AngeloGioacchino Del Regno]

LAB and IBB regulators can be current-limited by setting the
appropriate registers, but this operation is granted only after
sending an unlock code for secure access.

Besides the secure access, it would be possible to use the
regmap helper for get_current_limit, as there is no security
blocking reads, but I chose not to as to avoid having a very
big array containing current limits, especially for IBB.

That said, these regulators support current limiting for:
- LAB (pos): 200-1600mA, with 200mA per step (8 steps),
- IBB (neg):   0-1550mA, with  50mA per step (32 steps).

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
---
 drivers/regulator/qcom-labibb-regulator.c | 92 +++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index 0fe0f6bce4cf..0643713d6aad 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -29,6 +29,15 @@
 #define LABIBB_STATUS1_VREG_OK_BIT	BIT(7)
 #define LABIBB_CONTROL_ENABLE		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_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))
 
@@ -37,11 +46,18 @@
 #define IBB_ENABLE_TIME			(LABIBB_OFF_ON_DELAY * 10)
 #define LABIBB_POLL_ENABLED_TIME	1000
 
+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;
 	u16				base;
 	u8				type;
 };
@@ -53,6 +69,57 @@ struct labibb_regulator_data {
 	const struct regulator_desc	*desc;
 };
 
+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 const struct regulator_ops qcom_labibb_ops = {
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,
@@ -61,6 +128,8 @@ static const struct regulator_ops qcom_labibb_ops = {
 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
 	.list_voltage		= regulator_list_voltage_linear,
 	.map_voltage		= regulator_map_voltage_linear,
+	.set_current_limit	= qcom_labibb_set_current_limit,
+	.get_current_limit	= qcom_labibb_get_current_limit,
 };
 
 static const struct regulator_desc pmi8998_lab_desc = {
@@ -73,6 +142,9 @@ static const struct regulator_desc pmi8998_lab_desc = {
 	.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,
@@ -92,6 +164,9 @@ static const struct regulator_desc pmi8998_ibb_desc = {
 	.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,
@@ -163,6 +238,23 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
 		vreg->base = reg_data->base;
 		vreg->type = reg_data->type;
 
+		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;
 		vreg->desc.name = reg_data->name;
-- 
2.30.0

[PATCH v4 3/7] regulator: qcom-labibb: Implement pull-down, softstart, active discharge

[AngeloGioacchino Del Regno]

Soft start is required to avoid inrush current during LAB ramp-up and
IBB ramp-down, protecting connected hardware to which we supply voltage.

Since soft start is configurable on both LAB and IBB regulators, it
was necessary to add two DT properties, respectively "qcom,soft-start-us"
to control LAB ramp-up and "qcom,discharge-resistor-kohms" to control
the discharge resistor for IBB ramp-down, which obviously brought the
need of implementing a of_parse callback for both regulators.

Finally, also implement pull-down mode in order to avoid unpredictable
behavior when the regulators are disabled (random voltage spikes etc).

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/regulator/qcom-labibb-regulator.c | 94 +++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index 0643713d6aad..4d68b69b5a52 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -29,12 +29,23 @@
 #define LABIBB_STATUS1_VREG_OK_BIT	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
 
@@ -60,6 +71,8 @@ struct labibb_regulator {
 	struct labibb_current_limits	uA_limits;
 	u16				base;
 	u8				type;
+	u8				dischg_sel;
+	u8				soft_start_sel;
 };
 
 struct labibb_regulator_data {
@@ -120,6 +133,70 @@ static int qcom_labibb_get_current_limit(struct regulator_dev *rdev)
 	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,
@@ -128,8 +205,11 @@ static const struct regulator_ops qcom_labibb_ops = {
 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
 	.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,
 };
 
 static const struct regulator_desc pmi8998_lab_desc = {
@@ -138,6 +218,10 @@ 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),
@@ -152,6 +236,7 @@ static const struct regulator_desc pmi8998_lab_desc = {
 	.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 = {
@@ -160,6 +245,14 @@ 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),
@@ -174,6 +267,7 @@ static const struct regulator_desc pmi8998_ibb_desc = {
 	.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[] = {
-- 
2.30.0

[PATCH v4 4/7] dt-bindings: regulator: qcom-labibb: Document soft start properties

[AngeloGioacchino Del Regno]

Document properties to configure soft start and discharge resistor
for LAB and IBB respectively.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 .../bindings/regulator/qcom-labibb-regulator.yaml      | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
index 53853ec20fe2..7a507692f1ba 100644
--- a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
+++ b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
@@ -22,6 +22,11 @@ properties:
     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
@@ -35,6 +40,11 @@ properties:
     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
-- 
2.30.0

[PATCH v4 5/7] regulator: qcom-labibb: Implement short-circuit and over-current IRQs

[AngeloGioacchino Del Regno]

Short-Circuit Protection (SCP) and Over-Current Protection (OCP) are
very important for regulators like LAB and IBB, which are designed to
provide from very small to relatively big amounts of current to the
device (normally, a display).

Now that this regulator supports both voltage setting and current
limiting in this driver, to me it looked like being somehow essential
to provide support for SCP and OCP, for two reasons:
1. SCP is a drastic measure to prevent damaging "more" hardware in
   the worst situations, if any was damaged, preventing potentially
   drastic issues;
2. OCP is a great way to protect the hardware that we're powering
   through these regulators as if anything bad happens, the HW will
   draw more current than expected: in this case, the OCP interrupt
   will fire and the regulators will be immediately shut down,
   preventing hardware damage in many cases.

Both interrupts were successfully tested in a "sort-of" controlled
manner, with the following methodology:

Short-Circuit Protection (SCP):
1. Set LAB/IBB to 4.6/-1.4V, current limit 200mA/50mA;
2. Connect a 10 KOhm resistor to LAB/IBB by poking the right traces
   on a FxTec Pro1 smartphone for a very brief time (in short words,
   "just a rapid touch with flying wires");
3. The Short-Circuit protection trips: IRQ raises, regulators get
   cut. Recovery OK, test repeated without rebooting, OK.

Over-Current Protection (OCP):
1. Set LAB/IBB to the expected voltage to power up the display of
   a Sony Xperia XZ Premium smartphone (Sharp LS055D1SX04), set
   current limit to LAB 200mA, IBB 50mA (the values that this
   display unit needs are 200/800mA);
2. Boot the kernel: OCP fires. Recovery never happens because
   the selected current limit is too low, but that's expected.
   Test OK.

3. Set LAB/IBB to the expected current limits for XZ Premium
   (LAB 200mA, IBB 800mA), but lower than expected voltage,
   specifically LAB 5.4V, IBB -5.6V (instead of 5.6, -5.8V);
4. Boot the kernel: OCP fires. Recovery never happens because
   the selected voltage (still in the working range limits)
   is producing a current draw of more than 200mA on LAB.
   Test OK.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
---
 drivers/regulator/qcom-labibb-regulator.c | 518 +++++++++++++++++++++-
 1 file changed, 515 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index 4d68b69b5a52..dbb4511c3c6d 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -17,8 +17,20 @@
 
 #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)
@@ -26,8 +38,7 @@
  #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)
@@ -56,6 +67,11 @@
 #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;
@@ -69,10 +85,17 @@ struct labibb_regulator {
 	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 {
@@ -82,6 +105,450 @@ 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)
 {
@@ -210,6 +677,7 @@ static const struct regulator_ops qcom_labibb_ops = {
 	.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 = {
@@ -287,7 +755,7 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
 	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;
@@ -305,6 +773,8 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
 		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.
@@ -327,10 +797,44 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
 		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:
@@ -365,6 +869,14 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
 					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;
-- 
2.30.0

[PATCH v4 6/7] dt-bindings: regulator: qcom-labibb: Document SCP/OCP interrupts

[AngeloGioacchino Del Regno]

Short-Circuit Protection (SCP) and Over-Current Protection (OCP) are
now implemented in the driver: document the interrupts.
This also fixes wrong documentation about the SCP interrupt for LAB.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 .../regulator/qcom-labibb-regulator.yaml      | 20 +++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
index 7a507692f1ba..cf784bd1f5e5 100644
--- a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
+++ b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
@@ -29,9 +29,10 @@ properties:
         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
@@ -47,9 +48,10 @@ properties:
         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
@@ -67,13 +69,15 @@ examples:
       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";
       };
     };
 
-- 
2.30.0

[PATCH v4 7/7] arm64: dts: pmi8998: Add the right interrupts for LAB/IBB SCP and OCP

[AngeloGioacchino Del Regno]

In commit 208921bae696 ("arm64: dts: qcom: pmi8998: Add nodes for
LAB and IBB regulators") bindings for the lab/ibb regulators were
added to the pmi8998 dt, but the original committer has never
specified what the interrupts were for.
LAB and IBB regulators provide two interrupts, SC-ERR (short
circuit error) and VREG-OK but, in that commit, the regulators
were provided with two different types of interrupts;
specifically, IBB had the SC-ERR interrupt, while LAB had the
VREG-OK one, none of which were (luckily) used, since the driver
didn't actually use these at all.
Assuming that the original intention was to have the SC IRQ in
both LAB and IBB, as per the names appearing in documentation,
fix the SCP interrupt.

While at it, also add the OCP interrupt in order to be able to
enable the Over-Current Protection feature, if requested.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 arch/arm64/boot/dts/qcom/pmi8998.dtsi | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/pmi8998.dtsi b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
index d016b12967eb..d230c510d4b7 100644
--- a/arch/arm64/boot/dts/qcom/pmi8998.dtsi
+++ b/arch/arm64/boot/dts/qcom/pmi8998.dtsi
@@ -30,11 +30,15 @@ labibb {
 			compatible = "qcom,pmi8998-lab-ibb";
 
 			ibb: ibb {
-				interrupts = <0x3 0xdc 0x2 IRQ_TYPE_EDGE_RISING>;
+				interrupts = <0x3 0xdc 0x2 IRQ_TYPE_EDGE_RISING>,
+					     <0x3 0xdc 0x0 IRQ_TYPE_LEVEL_HIGH>;
+				interrupt-names = "sc-err", "ocp";
 			};
 
 			lab: lab {
-				interrupts = <0x3 0xde 0x0 IRQ_TYPE_EDGE_RISING>;
+				interrupts = <0x3 0xde 0x1 IRQ_TYPE_EDGE_RISING>,
+					     <0x3 0xde 0x0 IRQ_TYPE_LEVEL_LOW>;
+				interrupt-names = "sc-err", "ocp";
 			};
 		};
 	};
-- 
2.30.0

Re: (subset) [PATCH v4 0/7] Really implement Qualcomm LAB/IBB regulators

[Mark Brown]

On Tue, 19 Jan 2021 18:44:14 +0100, AngeloGioacchino Del Regno wrote:
> 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.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/7] regulator: qcom-labibb: Switch voltage ops from linear_range to linear
      commit: 9a12eb704ea27826ece4414cb8822388ec54883c
[2/7] regulator: qcom-labibb: Implement current limiting
      commit: 8056704ba948c1c54c7a67d78a8399a749f2d04b
[3/7] regulator: qcom-labibb: Implement pull-down, softstart, active discharge
      commit: 3bc7cb99fb6eafae5a40bf71ded444df70a425f7
[4/7] dt-bindings: regulator: qcom-labibb: Document soft start properties
      commit: 5581304004659ddc8d0d45561c1f2abfe080b4d4
[5/7] regulator: qcom-labibb: Implement short-circuit and over-current IRQs
      commit: 390af53e04114f790d60b63802a4de9d815ade03
[6/7] dt-bindings: regulator: qcom-labibb: Document SCP/OCP interrupts
      commit: 9499200484669fe33c20c735a3d5a29a0dc0e9d4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [PATCH v4 4/7] dt-bindings: regulator: qcom-labibb: Document soft start properties

[Rob Herring]

On Tue, Jan 19, 2021 at 06:44:18PM +0100, AngeloGioacchino Del Regno wrote:
> Document properties to configure soft start and discharge resistor
> for LAB and IBB respectively.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  .../bindings/regulator/qcom-labibb-regulator.yaml      | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> index 53853ec20fe2..7a507692f1ba 100644
> --- a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> +++ b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> @@ -22,6 +22,11 @@ properties:
>      type: object
>  
>      properties:
> +      qcom,soft-start-us:
> +        $ref: /schemas/types.yaml#/definitions/uint32

Don't need a type when you have standard units.

> +        description: Regulator soft start time in microseconds.
> +        enum: [200, 400, 600, 800]
> +        default: 200
>  
>        interrupts:
>          maxItems: 1
> @@ -35,6 +40,11 @@ properties:
>      type: object
>  
>      properties:
> +      qcom,discharge-resistor-kohms:

-kohms is not standard units as documented in property-units.txt (and 
.yaml in dtschema). Please use '-ohms'.

Given this is already applied, send an incremental patch.

> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Discharge resistor value in KiloOhms.
> +        enum: [300, 64, 32, 16]
> +        default: 300
>  
>        interrupts:
>          maxItems: 1
> -- 
> 2.30.0
> 

Re: [PATCH v4 6/7] dt-bindings: regulator: qcom-labibb: Document SCP/OCP interrupts

[Rob Herring]

On Tue, Jan 19, 2021 at 06:44:20PM +0100, AngeloGioacchino Del Regno wrote:
> Short-Circuit Protection (SCP) and Over-Current Protection (OCP) are
> now implemented in the driver: document the interrupts.
> This also fixes wrong documentation about the SCP interrupt for LAB.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  .../regulator/qcom-labibb-regulator.yaml      | 20 +++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> index 7a507692f1ba..cf784bd1f5e5 100644
> --- a/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> +++ b/Documentation/devicetree/bindings/regulator/qcom-labibb-regulator.yaml
> @@ -29,9 +29,10 @@ properties:
>          default: 200
>  
>        interrupts:
> -        maxItems: 1
> +        minItems: 1
> +        maxItems: 2
>          description:
> -          Short-circuit interrupt for lab.
> +          Short-circuit and over-current interrupts for lab.

minItems: 1
items:
  - description: Short-circuit interrupt
  - description: over-current interrupt

>  
>      required:
>        - interrupts
> @@ -47,9 +48,10 @@ properties:
>          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
> @@ -67,13 +69,15 @@ examples:
>        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";
>        };
>      };
>  
> -- 
> 2.30.0
>