regulator: qpnp-labibb: Add logic to skip second SWIRE command

On newer AMOLED panels the second SWIRE command is expected to
control the AVDD voltage. However, the PMI8950/PMI8994 IBB module
interprets this command for VDISN and incorrectly reduces its voltage.

Add DT properties 'qcom,skip-2nd-swire-cmd' to skip the second
SWIRE command and 'qcom,swire-2nd-cmd-delay' to explicitly specify
the delay between the first and second SWIRE command.

CRs-Fixed: 938038
Change-Id: I617a8490784efd760651b3ec8780cc4fd4b17bae
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>

Documentation/devicetree/bindings/regulator/qpnp-labibb-regulator.txt

@@ -34,6 +34,13 @@ Main node optional properties:
 					if qpnp,qpnp-labibb-mode = "amoled".
 - qcom,labibb-ttw-force-lab-on:		A boolean property which forces LAB to be
 					always on during TTW mode.
+- qcom,skip-2nd-swire-cmd:		A boolean property which indicates if
+					the second SWIRE command needs to be skipped.
+- qcom,swire-2nd-cmd-delay:		A integer value which specifes the
+					delay in millisecs between the first and second
+					SWIRE command. If not specified this value
+					defaults to 20ms. This delay is applied only
+					if 'qpnp,skip-2nd-swire-cmd' is defined.
 
 LAB subnode required properties:
 
@@ -203,12 +210,16 @@ Example:
 			#size-cells = <1>;
 			qpnp,qpnp-labibb-mode = "lcd";
 			qcom,pmic-revid = <&pmi8994_revid>;
+			qcom,skip-2nd-swire-cmd;
 
 			lab_regulator: qcom,lab@de00 {
 				reg = <0xde00 0x100>;
 				reg-names = "lab";
-				regulator-name = "lab_reg";
 
+				interrupts = <0x3 0xde 0x0>;
+                                interrupt-names = "lab-vreg-ok";
+
+				regulator-name = "lab_reg";
 				regulator-min-microvolt = <4600000>;
 				regulator-max-microvolt = <6000000>;
 

drivers/regulator/qpnp-labibb-regulator.c

@@ -15,11 +15,13 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/regmap.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
 #include <linux/spmi.h>
 #include <linux/platform_device.h>
 #include <linux/string.h>
@@ -247,6 +249,9 @@
 #define IBB_DIS_DLY_MASK		((1 << IBB_DIS_DLY_BITS) - 1)
 #define IBB_WAIT_MBG_OK			BIT(2)
 
+/* Constants */
+#define SWIRE_DEFAULT_2ND_CMD_DLY_MS	20
+
 enum pmic_subtype {
 	PMI8994		= 10,
 	PMI8950		= 17,
@@ -280,6 +285,7 @@ enum ibb_mode {
 	IBB_SW_CONTROL_EN,
 	IBB_SW_CONTROL_DIS,
 	IBB_HW_CONTROL,
+	IBB_HW_SW_CONTROL,
 };
 
 static const int ibb_discharge_resistor_plan[] = {
@@ -437,6 +443,7 @@ struct lab_regulator {
 	struct regulator_dev		*rdev;
 	struct mutex			lab_mutex;
 
+	int				lab_vreg_ok_irq;
 	int				curr_volt;
 	int				min_volt;
 
@@ -480,6 +487,8 @@ struct qpnp_labibb {
 	bool				ibb_settings_saved;
 	bool				swire_control;
 	bool				ttw_force_lab_on;
+	bool				skip_2nd_swire_cmd;
+	u32				swire_2nd_cmd_delay;
 };
 
 enum ibb_settings_index {
@@ -654,6 +663,8 @@ static int qpnp_ibb_set_mode(struct qpnp_labibb *labibb, enum ibb_mode mode)
 		val = IBB_ENABLE_CTL_MODULE_EN;
 	else if (mode == IBB_HW_CONTROL)
 		val = IBB_ENABLE_CTL_SWIRE_RDY;
+	else if (mode == IBB_HW_SW_CONTROL)
+		val = IBB_ENABLE_CTL_MODULE_EN | IBB_ENABLE_CTL_SWIRE_RDY;
 	else if (mode == IBB_SW_CONTROL_DIS)
 		val = 0;
 	else
@@ -1556,6 +1567,77 @@ static int qpnp_lab_regulator_set_voltage(struct regulator_dev *rdev,
 	return 0;
 }
 
+static int qpnp_skip_swire_command(struct qpnp_labibb *labibb)
+{
+	int rc = 0, retry = 50, dly;
+	u8 reg;
+
+	do {
+		/* poll for ibb vreg_ok */
+		rc = qpnp_labibb_read(labibb, &reg,
+			labibb->ibb_base + REG_IBB_STATUS1, 1);
+		if (rc) {
+			pr_err("Failed to read ibb_status1 reg rc=%d\n", rc);
+			return rc;
+		}
+		if ((reg & IBB_STATUS1_VREG_OK_MASK) == IBB_STATUS1_VREG_OK)
+			break;
+
+		/* poll delay */
+		usleep_range(500, 600);
+
+	} while (--retry);
+
+	if (!retry) {
+		pr_err("ibb vreg_ok failed to turn-on\n");
+		return -EBUSY;
+	}
+
+	/* move to SW control */
+	rc = qpnp_ibb_set_mode(labibb, IBB_SW_CONTROL_EN);
+	if (rc) {
+		pr_err("Failed switch to IBB_SW_CONTROL rc=%d\n", rc);
+		return rc;
+	}
+
+	/* delay to skip the second swire command */
+	dly = labibb->swire_2nd_cmd_delay * 1000;
+	while (dly / 20000) {
+		usleep_range(20000, 20010);
+		dly -= 20000;
+	}
+	if (dly)
+		usleep_range(dly, dly + 10);
+
+	rc = qpnp_ibb_set_mode(labibb, IBB_HW_SW_CONTROL);
+	if (rc) {
+		pr_err("Failed switch to IBB_HW_SW_CONTROL rc=%d\n", rc);
+		return rc;
+	}
+
+	/* delay for SPMI to SWIRE transition */
+	usleep_range(1000, 1100);
+
+	/* Move back to SWIRE control */
+	rc = qpnp_ibb_set_mode(labibb, IBB_HW_CONTROL);
+	if (rc)
+		pr_err("Failed switch to IBB_HW_CONTROL rc=%d\n", rc);
+
+	return rc;
+}
+
+static irqreturn_t lab_vreg_ok_handler(int irq, void *_labibb)
+{
+	struct qpnp_labibb *labibb = _labibb;
+	int rc;
+
+	rc = qpnp_skip_swire_command(labibb);
+	if (rc)
+		pr_err("Failed in 'qpnp_skip_swire_command' rc=%d\n", rc);
+
+	return IRQ_HANDLED;
+}
+
 static int qpnp_lab_regulator_get_voltage(struct regulator_dev *rdev)
 {
 	struct qpnp_labibb *labibb  = rdev_get_drvdata(rdev);
@@ -1707,6 +1789,19 @@ static int register_qpnp_lab_regulator(struct qpnp_labibb *labibb,
 		}
 	}
 
+	if (labibb->skip_2nd_swire_cmd) {
+		rc = devm_request_threaded_irq(labibb->dev,
+				labibb->lab_vreg.lab_vreg_ok_irq, NULL,
+				lab_vreg_ok_handler,
+				IRQF_ONESHOT | IRQF_TRIGGER_RISING,
+				"lab-vreg-ok", labibb);
+		if (rc) {
+			pr_err("Failed to register 'lab-vreg-ok' irq rc=%d\n",
+						rc);
+			return rc;
+		}
+	}
+
 	rc = qpnp_labibb_read(labibb, &val,
 				labibb->ibb_base + REG_IBB_ENABLE_CTL, 1);
 	if (rc) {
@@ -2520,6 +2615,21 @@ static int register_qpnp_ibb_regulator(struct qpnp_labibb *labibb,
 	return 0;
 }
 
+static int qpnp_lab_register_irq(struct device_node *child,
+				struct qpnp_labibb *labibb)
+{
+	if (labibb->skip_2nd_swire_cmd) {
+		labibb->lab_vreg.lab_vreg_ok_irq =
+					of_irq_get_byname(child, "lab-vreg-ok");
+		if (labibb->lab_vreg.lab_vreg_ok_irq < 0) {
+			pr_err("Invalid lab-vreg-ok irq\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int qpnp_labibb_check_ttw_supported(struct qpnp_labibb *labibb)
 {
 	int rc = 0;
@@ -2629,6 +2739,17 @@ static int qpnp_labibb_regulator_probe(struct platform_device *pdev)
 		pr_err("Invalid mode for SWIRE control\n");
 		return -EINVAL;
 	}
+	if (labibb->swire_control) {
+		labibb->skip_2nd_swire_cmd =
+				of_property_read_bool(labibb->dev->of_node,
+				"qcom,skip-2nd-swire-cmd");
+		rc = of_property_read_u32(labibb->dev->of_node,
+				"qcom,swire-2nd-cmd-delay",
+				&labibb->swire_2nd_cmd_delay);
+		if (rc)
+			labibb->swire_2nd_cmd_delay =
+					SWIRE_DEFAULT_2ND_CMD_DLY_MS;
+	}
 
 	if (of_get_available_child_count(pdev->dev.of_node) == 0) {
 		pr_err("no child nodes\n");
@@ -2653,6 +2774,12 @@ static int qpnp_labibb_regulator_probe(struct platform_device *pdev)
 		switch (type) {
 		case QPNP_LAB_TYPE:
 			labibb->lab_base = base;
+			rc = qpnp_lab_register_irq(child, labibb);
+			if (rc) {
+				pr_err("Failed to register LAB IRQ rc=%d\n",
+							rc);
+				goto fail_registration;
+			}
 			rc = register_qpnp_lab_regulator(labibb, child);
 			if (rc)
 				goto fail_registration;