[PATCH v3 3/4] hwmon: (pmbus/core): Implement irq support

[Naresh Solanki]

From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>

Implement PMBUS irq handler to notify regulator events.

Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
---
 drivers/hwmon/pmbus/pmbus.h      |   2 +-
 drivers/hwmon/pmbus/pmbus_core.c | 151 ++++++++++++++++++++++++++++---
 2 files changed, 137 insertions(+), 16 deletions(-)

diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index 10fb17879f8e..6b2e6cf93b19 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -26,7 +26,7 @@ enum pmbus_regs {
 
 	PMBUS_CAPABILITY		= 0x19,
 	PMBUS_QUERY			= 0x1A,
-
+	PMBUS_SMBALERT_MASK		= 0x1B,
 	PMBUS_VOUT_MODE			= 0x20,
 	PMBUS_VOUT_COMMAND		= 0x21,
 	PMBUS_VOUT_TRIM			= 0x22,
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 9a9e380acc23..613e2e484a0f 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -81,6 +81,7 @@ struct pmbus_label {
 struct pmbus_data {
 	struct device *dev;
 	struct device *hwmon_dev;
+	struct regulator_dev **rdevs;
 
 	u32 flags;		/* from platform data */
 
@@ -2804,7 +2805,8 @@ static const struct pmbus_regulator_status_category pmbus_regulator_flag_map[] =
 	},
 };
 
-static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
+static int pmbus_regulator_get_flags(struct regulator_dev *rdev, unsigned int *error,
+				    unsigned int *event)
 {
 	int i, status;
 	const struct pmbus_regulator_status_category *cat;
@@ -2815,7 +2817,8 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
 	u8 page = rdev_get_id(rdev);
 	int func = data->info->func[page];
 
-	*flags = 0;
+	*error = 0;
+	*event = 0;
 
 	mutex_lock(&data->update_lock);
 
@@ -2831,8 +2834,10 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
 		}
 
 		for (bit = cat->bits; bit->pflag; bit++) {
-			if (status & bit->pflag)
-				*flags |= bit->rflag;
+			if (status & bit->pflag) {
+				*error |= bit->rflag;
+				*event |= bit->eflag;
+			}
 		}
 	}
 
@@ -2851,11 +2856,15 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
 		return status;
 
 	if (pmbus_regulator_is_enabled(rdev)) {
-		if (status & PB_STATUS_OFF)
-			*flags |= REGULATOR_ERROR_FAIL;
+		if (status & PB_STATUS_OFF) {
+			*error |= REGULATOR_ERROR_FAIL;
+			*event |= REGULATOR_EVENT_FAIL;
+		}
 
-		if (status & PB_STATUS_POWER_GOOD_N)
-			*flags |= REGULATOR_ERROR_REGULATION_OUT;
+		if (status & PB_STATUS_POWER_GOOD_N) {
+			*error |= REGULATOR_ERROR_REGULATION_OUT;
+			*event |= REGULATOR_EVENT_REGULATION_OUT;
+		}
 	}
 
 	/*
@@ -2863,13 +2872,22 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
 	 * PMBUS_STATUS_TEMPERATURE, map PB_STATUS_TEMPERATURE to a warning as
 	 * a (conservative) best-effort interpretation.
 	 */
-	if (!(*flags & (REGULATOR_ERROR_OVER_TEMP | REGULATOR_ERROR_OVER_TEMP_WARN)) &&
-	    (status & PB_STATUS_TEMPERATURE))
-		*flags |= REGULATOR_ERROR_OVER_TEMP_WARN;
+	if (!(*error & (REGULATOR_ERROR_OVER_TEMP | REGULATOR_ERROR_OVER_TEMP_WARN)) &&
+	    (status & PB_STATUS_TEMPERATURE)) {
+		*error |= REGULATOR_ERROR_OVER_TEMP_WARN;
+		*event |= REGULATOR_EVENT_OVER_TEMP_WARN;
+	}
 
 	return 0;
 }
 
+static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
+{
+	unsigned int event;
+
+	return pmbus_regulator_get_flags(rdev, flags, &event);
+}
+
 static int pmbus_regulator_get_status(struct regulator_dev *rdev)
 {
 	struct device *dev = rdev_get_dev(rdev);
@@ -3060,14 +3078,61 @@ const struct regulator_ops pmbus_regulator_ops = {
 };
 EXPORT_SYMBOL_NS_GPL(pmbus_regulator_ops, PMBUS);
 
+static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
+{
+	return pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+}
+
+static irqreturn_t pmbus_fault_handler(int irq, void *pdata)
+{
+	struct pmbus_data *data = pdata;
+	struct i2c_client *client = to_i2c_client(data->dev);
+	int i, ret = IRQ_NONE, status, event;
+	u8 page;
+
+	for (i = 0; i < data->info->num_regulators; i++) {
+
+		if (!data->rdevs[i])
+			continue;
+
+		ret = pmbus_regulator_get_flags(data->rdevs[i], &status, &event);
+		if (ret)
+			return ret;
+
+		if (event) {
+			regulator_notifier_call_chain(data->rdevs[i], event, NULL);
+			ret = IRQ_HANDLED;
+		}
+
+		page = rdev_get_id(data->rdevs[i]);
+		mutex_lock(&data->update_lock);
+		status = pmbus_read_status_word(client, page);
+		if (status < 0) {
+			mutex_unlock(&data->update_lock);
+			return status;
+		}
+
+		if (status & ~(PB_STATUS_OFF | PB_STATUS_BUSY | PB_STATUS_POWER_GOOD_N))
+			pmbus_clear_fault_page(client, page);
+
+		mutex_unlock(&data->update_lock);
+	}
+
+	return ret;
+}
+
 static int pmbus_regulator_register(struct pmbus_data *data)
 {
 	struct device *dev = data->dev;
 	const struct pmbus_driver_info *info = data->info;
 	const struct pmbus_platform_data *pdata = dev_get_platdata(dev);
-	struct regulator_dev *rdev;
 	int i;
 
+	data->rdevs = devm_kzalloc(dev, sizeof(struct regulator_dev *) * info->num_regulators,
+				  GFP_KERNEL);
+	if (!data->rdevs)
+		return -ENOMEM;
+
 	for (i = 0; i < info->num_regulators; i++) {
 		struct regulator_config config = { };
 
@@ -3077,21 +3142,71 @@ static int pmbus_regulator_register(struct pmbus_data *data)
 		if (pdata && pdata->reg_init_data)
 			config.init_data = &pdata->reg_init_data[i];
 
-		rdev = devm_regulator_register(dev, &info->reg_desc[i],
+		data->rdevs[i] = devm_regulator_register(dev, &info->reg_desc[i],
 					       &config);
-		if (IS_ERR(rdev))
-			return dev_err_probe(dev, PTR_ERR(rdev),
+		if (IS_ERR(data->rdevs[i]))
+			return dev_err_probe(dev, PTR_ERR(data->rdevs[i]),
 					     "Failed to register %s regulator\n",
 					     info->reg_desc[i].name);
 	}
 
 	return 0;
 }
+
+static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
+{
+	struct device *dev = &client->dev;
+	const struct pmbus_regulator_status_category *cat;
+	const struct pmbus_regulator_status_assoc *bit;
+	int i, j, err, ret;
+	u8 mask;
+	int func;
+
+	for (i = 0; i < data->info->pages; i++) {
+		func = data->info->func[i];
+
+		for (j = 0; j < ARRAY_SIZE(pmbus_regulator_flag_map); j++) {
+			cat = &pmbus_regulator_flag_map[i];
+			if (!(func & cat->func))
+				continue;
+			mask = 0;
+			for (bit = cat->bits; bit->pflag; bit++)
+				mask |= bit->pflag;
+
+			err = pmbus_write_smbalert_mask(client, i, cat->reg, ~mask);
+			if (err)
+				dev_err(dev, "Failed to set smbalert for reg 0x%02x\n",	cat->reg);
+		}
+
+		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_CML, 0xff);
+		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_OTHER, 0xff);
+		pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_MFR_SPECIFIC, 0xff);
+		if (data->info->func[i] & PMBUS_HAVE_FAN12)
+			pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_FAN_12, 0xff);
+		if (data->info->func[i] & PMBUS_HAVE_FAN34)
+			pmbus_write_smbalert_mask(client, i, PMBUS_STATUS_FAN_34, 0xff);
+
+	}
+
+	/* Register notifiers - can fail if IRQ is not given */
+	ret = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler,
+			      0, "pmbus-irq", data);
+	if (ret) {
+		dev_warn(dev, "IRQ disabled %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
 #else
 static int pmbus_regulator_register(struct pmbus_data *data)
 {
 	return 0;
 }
+static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
+{
+	return 0;
+}
 #endif
 
 static struct dentry *pmbus_debugfs_dir;	/* pmbus debugfs directory */
@@ -3456,6 +3571,12 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
 	if (ret)
 		return ret;
 
+	if (client->irq > 0) {
+		ret = pmbus_irq_setup(client, data);
+		if (ret)
+			return ret;
+	}
+
 	ret = pmbus_init_debugfs(client, data);
 	if (ret)
 		dev_warn(dev, "Failed to register debugfs\n");
-- 
2.37.3