[PATCH 4/4] regulator: adding interrupt handling in labibb regulator

From: Nisha Kumari
Date: Wed Jun 12 2019 - 07:06:10 EST


This patch adds short circuit interrupt handling and recovery.

Signed-off-by: Nisha Kumari <nishakumari@xxxxxxxxxxxxxx>
---
drivers/regulator/qcom-labibb-regulator.c | 161 ++++++++++++++++++++++++++++++
1 file changed, 161 insertions(+)

diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index 0c68883..04fc9512 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019, The Linux Foundation. All rights reserved.

+#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
@@ -16,22 +17,28 @@
#define REG_LAB_ENABLE_CTL 0x46
#define LAB_STATUS1_VREG_OK_BIT BIT(7)
#define LAB_ENABLE_CTL_EN BIT(7)
+#define LAB_STATUS1_SC_DETECT_BIT BIT(6)

#define REG_IBB_STATUS1 0x08
#define REG_IBB_ENABLE_CTL 0x46
#define IBB_STATUS1_VREG_OK_BIT BIT(7)
#define IBB_ENABLE_CTL_MASK (BIT(7) | BIT(6))
#define IBB_CONTROL_ENABLE BIT(7)
+#define IBB_STATUS1_SC_DETECT_BIT BIT(6)

#define POWER_DELAY 8000
+#define POLLING_SCP_DONE_COUNT 2
+#define POLLING_SCP_DONE_INTERVAL_MS 5

struct lab_regulator {
struct regulator_dev *rdev;
+ int lab_sc_irq;
int vreg_enabled;
};

struct ibb_regulator {
struct regulator_dev *rdev;
+ int ibb_sc_irq;
int vreg_enabled;
};

@@ -288,6 +295,112 @@ static int qcom_ibb_regulator_is_enabled(struct regulator_dev *rdev)
.owner = THIS_MODULE,
};

+static void labibb_sc_err_recovery_work(void *_labibb)
+{
+ int ret;
+ struct qcom_labibb *labibb = (struct qcom_labibb *)_labibb;
+
+ labibb->ibb_vreg.vreg_enabled = 0;
+ labibb->lab_vreg.vreg_enabled = 0;
+
+ ret = qcom_ibb_regulator_enable(labibb->lab_vreg.rdev);
+ if (ret < 0) {
+ dev_err(labibb->dev,
+ "Interrupt recovery not possible as IBB enable failed");
+ return;
+ }
+
+ ret = qcom_lab_regulator_enable(labibb->ibb_vreg.rdev);
+ if (ret < 0) {
+ dev_err(labibb->dev,
+ "Interrupt recovery not possible as LAB enable failed");
+ ret = qcom_ibb_regulator_disable(labibb->lab_vreg.rdev);
+ if (ret < 0)
+ dev_err(labibb->dev, "IBB disable failed");
+ return;
+ }
+ dev_info(labibb->dev, "Interrupt recovery done");
+}
+
+static irqreturn_t labibb_sc_err_handler(int irq, void *_labibb)
+{
+ int ret, count;
+ u16 reg;
+ u8 sc_err_mask, val;
+ char *str;
+ struct qcom_labibb *labibb = (struct qcom_labibb *)_labibb;
+ bool in_sc_err, lab_en, ibb_en, scp_done = false;
+
+ if (irq == labibb->lab_vreg.lab_sc_irq) {
+ reg = labibb->lab_base + REG_LAB_STATUS1;
+ sc_err_mask = LAB_STATUS1_SC_DETECT_BIT;
+ str = "LAB";
+ } else if (irq == labibb->ibb_vreg.ibb_sc_irq) {
+ reg = labibb->ibb_base + REG_IBB_STATUS1;
+ sc_err_mask = IBB_STATUS1_SC_DETECT_BIT;
+ str = "IBB";
+ } else {
+ return IRQ_HANDLED;
+ }
+
+ ret = qcom_labibb_read(labibb, reg, &val, 1);
+ if (ret < 0) {
+ dev_err(labibb->dev, "Read failed, ret=%d\n", ret);
+ return IRQ_HANDLED;
+ }
+ dev_dbg(labibb->dev, "%s SC error triggered! %s_STATUS1 = %d\n",
+ str, str, val);
+
+ in_sc_err = !!(val & sc_err_mask);
+
+ /*
+ * The SC(short circuit) fault would trigger PBS(Portable Batch
+ * System) to disable regulators for protection. This would
+ * cause the SC_DETECT status being cleared so that it's not
+ * able to get the SC fault status.
+ * Check if LAB/IBB regulators are enabled in the driver but
+ * disabled in hardware, this means a SC fault had happened
+ * and SCP handling is completed by PBS.
+ */
+ if (!in_sc_err) {
+ count = POLLING_SCP_DONE_COUNT;
+ do {
+ reg = labibb->lab_base + REG_LAB_ENABLE_CTL;
+ ret = qcom_labibb_read(labibb, reg, &val, 1);
+ if (ret < 0) {
+ dev_err(labibb->dev,
+ "Read failed, ret=%d\n", ret);
+ return IRQ_HANDLED;
+ }
+ lab_en = !!(val & LAB_ENABLE_CTL_EN);
+
+ reg = labibb->ibb_base + REG_IBB_ENABLE_CTL;
+ ret = qcom_labibb_read(labibb, reg, &val, 1);
+ if (ret < 0) {
+ dev_err(labibb->dev,
+ "Read failed, ret=%d\n", ret);
+ return IRQ_HANDLED;
+ }
+ ibb_en = !!(val & IBB_CONTROL_ENABLE);
+ if (lab_en || ibb_en)
+ msleep(POLLING_SCP_DONE_INTERVAL_MS);
+ else
+ break;
+ } while ((lab_en || ibb_en) && count--);
+
+ if (labibb->lab_vreg.vreg_enabled &&
+ labibb->ibb_vreg.vreg_enabled && !lab_en && !ibb_en) {
+ dev_dbg(labibb->dev, "LAB/IBB has been disabled by SCP\n");
+ scp_done = true;
+ }
+ }
+
+ if (in_sc_err || scp_done)
+ labibb_sc_err_recovery_work(labibb);
+
+ return IRQ_HANDLED;
+}
+
static int register_lab_regulator(struct qcom_labibb *labibb,
struct device_node *of_node)
{
@@ -295,6 +408,20 @@ static int register_lab_regulator(struct qcom_labibb *labibb,
struct regulator_init_data *init_data;
struct regulator_config cfg = {};

+ (labibb->lab_vreg.lab_sc_irq > 0) {
+ ret = devm_request_threaded_irq(labibb->dev,
+ labibb->lab_vreg.lab_sc_irq,
+ NULL, labibb_sc_err_handler,
+ IRQF_ONESHOT |
+ IRQF_TRIGGER_RISING,
+ "lab-sc-err", labibb);
+ if (ret) {
+ dev_err(labibb->dev, "Failed to register 'lab-sc-err' irq ret=%d\n",
+ ret);
+ return ret;
+ }
+ }
+
cfg.dev = labibb->dev;
cfg.driver_data = labibb;
cfg.of_node = of_node;
@@ -326,6 +453,20 @@ static int register_ibb_regulator(struct qcom_labibb *labibb,
struct regulator_init_data *init_data;
struct regulator_config cfg = {};

+ if (labibb->ibb_vreg.ibb_sc_irq > 0) {
+ ret = devm_request_threaded_irq(labibb->dev,
+ labibb->ibb_vreg.ibb_sc_irq,
+ NULL, labibb_sc_err_handler,
+ IRQF_ONESHOT |
+ IRQF_TRIGGER_RISING,
+ "ibb-sc-err", labibb);
+ if (ret) {
+ dev_err(labibb->dev, "Failed to register 'ibb-sc-err' irq ret=%d\n",
+ ret);
+ return ret;
+ }
+ }
+
cfg.dev = labibb->dev;
cfg.driver_data = labibb;
cfg.of_node = of_node;
@@ -390,6 +531,16 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)
switch (type) {
case QCOM_LAB_TYPE:
labibb->lab_base = base;
+
+ labibb->lab_vreg.lab_sc_irq = -EINVAL;
+ ret = of_irq_get_byname(child, "lab-sc-err");
+ if (ret < 0)
+ dev_dbg(labibb->dev,
+ "Unable to get lab-sc-err, ret = %d\n",
+ ret);
+ else
+ labibb->lab_vreg.lab_sc_irq = ret;
+
ret = register_lab_regulator(labibb, child);
if (ret < 0) {
dev_err(labibb->dev,
@@ -400,6 +551,16 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev)

case QCOM_IBB_TYPE:
labibb->ibb_base = base;
+
+ labibb->ibb_vreg.ibb_sc_irq = -EINVAL;
+ ret = of_irq_get_byname(child, "ibb-sc-err");
+ if (ret < 0)
+ dev_dbg(labibb->dev,
+ "Unable to get ibb-sc-err, ret = %d\n",
+ ret);
+ else
+ labibb->ibb_vreg.ibb_sc_irq = ret;
+
ret = register_ibb_regulator(labibb, child);
if (ret < 0) {
dev_err(labibb->dev,
--
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