From:   Naresh Solanki <naresh.solanki@9elements.com>
To:     Guenter Roeck <linux@roeck-us.net>,
        Jean Delvare <jdelvare@suse.com>
Cc:     linux-hwmon@vger.kernel.org,
        Patrick Rudolph <patrick.rudolph@9elements.com>,
        Naresh Solanki <Naresh.Solanki@9elements.com>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v4 3/4] hwmon: (pmbus/core): Add interrupt support
Date:   Wed,  1 Mar 2023 17:44:33 +0100
Message-Id: <20230301164434.1928237-3-Naresh.Solanki@9elements.com>
In-Reply-To: <20230301164434.1928237-1-Naresh.Solanki@9elements.com>
References: <20230301164434.1928237-1-Naresh.Solanki@9elements.com>
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From: Patrick Rudolph <patrick.rudolph@9elements.com>

Implement PMBUS irq handler.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
...
Changes in V4:
- Clear fault using pmbus_clear_faults at end of interrupt handler.
- Remove for loop.
Changes in V3:
- Remove pmbus word check for SMBALERT writes
- Remove variable ret & use err instead.
- Use dev_dbg_once instead of error.
- Remove error print when writing to misc_status register.
- Move client irq check to pmbus_irq_setup.
---
 drivers/hwmon/pmbus/pmbus.h      |  2 +-
 drivers/hwmon/pmbus/pmbus_core.c | 70 ++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index 713ea7915425..11e84e141126 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 f8ac9016ea0e..dfd227459d8b 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3105,6 +3105,72 @@ static int pmbus_regulator_register(struct pmbus_data *data)
 }
 #endif
 
+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);
+
+	mutex_lock(&data->update_lock);
+	/* TODO: Check status flag & notify hwmon events */
+
+	pmbus_clear_faults(client);
+	mutex_unlock(&data->update_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
+{
+	struct device *dev = &client->dev;
+	const struct pmbus_status_category *cat;
+	const struct pmbus_status_assoc *bit;
+	int i, j, err, func;
+	u8 mask;
+
+	static const u8 misc_status[] = {PMBUS_STATUS_CML, PMBUS_STATUS_OTHER,
+					 PMBUS_STATUS_MFR_SPECIFIC, PMBUS_STATUS_FAN_12,
+					 PMBUS_STATUS_FAN_34};
+
+	if (!client->irq)
+		return 0;
+
+	for (i = 0; i < data->info->pages; i++) {
+		func = data->info->func[i];
+
+		for (j = 0; j < ARRAY_SIZE(pmbus_status_flag_map); j++) {
+			cat = &pmbus_status_flag_map[j];
+			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_dbg_once(dev, "Failed to set smbalert for reg 0x%02x\n",
+					     cat->reg);
+		}
+
+		for (j = 0; j < ARRAY_SIZE(misc_status); j++)
+			pmbus_write_smbalert_mask(client, i, misc_status[j], 0xff);
+	}
+
+	/* Register notifiers */
+	err = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler, 0,
+					"pmbus-irq", data);
+	if (err) {
+		dev_err(dev, "failed to request an irq %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static struct dentry *pmbus_debugfs_dir;	/* pmbus debugfs directory */
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
@@ -3467,6 +3533,10 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
 	if (ret)
 		return ret;
 
+	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");
-- 
2.39.1