linux-kernel - [PATCH V2 2/3] i2c: cadence: Split cdns_i2c_master

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Message-ID: <20240911103852.162234-3-manikanta.guntupalli@amd.com>
Date: Wed, 11 Sep 2024 16:08:51 +0530
From: Manikanta Guntupalli <manikanta.guntupalli@....com>
To: <git@....com>, <michal.simek@....com>, <andi.shyti@...nel.org>,
	<linux-arm-kernel@...ts.infradead.org>, <linux-i2c@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: <radhey.shyam.pandey@....com>, <srinivas.goud@....com>,
	<shubhrajyoti.datta@....com>, <manion05gk@...il.com>, Manikanta Guntupalli
	<manikanta.guntupalli@....com>
Subject: [PATCH V2 2/3] i2c: cadence: Split cdns_i2c_master_xfer for Atomic Mode

The cdns_i2c_master_xfer function has been refactored to separate
the common code. This change facilitates better support for atomic
mode operations by isolating the shared logic.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@....com>
Reviewed-by: Andi Shyti <andi.shyti@...nel.org>
---
Changes for V2:
Added review signature.
---
 drivers/i2c/busses/i2c-cadence.c | 100 ++++++++++++++++---------------
 1 file changed, 53 insertions(+), 47 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index d3f6ca2cb4d7..e689448d229f 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -866,46 +866,14 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
 	return 0;
 }
 
-/**
- * cdns_i2c_master_xfer - The main i2c transfer function
- * @adap:	pointer to the i2c adapter driver instance
- * @msgs:	pointer to the i2c message structure
- * @num:	the number of messages to transfer
- *
- * Initiates the send/recv activity based on the transfer message received.
- *
- * Return: number of msgs processed on success, negative error otherwise
- */
-static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
-				int num)
+static int cdns_i2c_master_common_xfer(struct i2c_adapter *adap,
+				       struct i2c_msg *msgs,
+				       int num)
 {
 	int ret, count;
 	u32 reg;
 	struct cdns_i2c *id = adap->algo_data;
 	bool hold_quirk;
-#if IS_ENABLED(CONFIG_I2C_SLAVE)
-	bool change_role = false;
-#endif
-
-	ret = pm_runtime_resume_and_get(id->dev);
-	if (ret < 0)
-		return ret;
-
-#if IS_ENABLED(CONFIG_I2C_SLAVE)
-	/* Check i2c operating mode and switch if possible */
-	if (id->dev_mode == CDNS_I2C_MODE_SLAVE) {
-		if (id->slave_state != CDNS_I2C_SLAVE_STATE_IDLE) {
-			ret = -EAGAIN;
-			goto out;
-		}
-
-		/* Set mode to master */
-		cdns_i2c_set_mode(CDNS_I2C_MODE_MASTER, id);
-
-		/* Mark flag to change role once xfer is completed */
-		change_role = true;
-	}
-#endif
 
 	/* Check if the bus is free */
 
@@ -917,7 +885,7 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 		ret = -EAGAIN;
 		if (id->adap.bus_recovery_info)
 			i2c_recover_bus(adap);
-		goto out;
+		return ret;
 	}
 
 	hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
@@ -937,8 +905,7 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			if (msgs[count].flags & I2C_M_RD) {
 				dev_warn(adap->dev.parent,
 					 "Can't do repeated start after a receive message\n");
-				ret = -EOPNOTSUPP;
-				goto out;
+				return -EOPNOTSUPP;
 			}
 		}
 		id->bus_hold_flag = 1;
@@ -956,26 +923,65 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 
 		ret = cdns_i2c_process_msg(id, msgs, adap);
 		if (ret)
-			goto out;
+			return ret;
 
 		/* Report the other error interrupts to application */
 		if (id->err_status) {
 			cdns_i2c_master_reset(adap);
 
-			if (id->err_status & CDNS_I2C_IXR_NACK) {
-				ret = -ENXIO;
-				goto out;
-			}
-			ret = -EIO;
-			goto out;
+			if (id->err_status & CDNS_I2C_IXR_NACK)
+				return -ENXIO;
+
+			return -EIO;
 		}
 	}
+	return 0;
+}
 
-	ret = num;
+/**
+ * cdns_i2c_master_xfer - The main i2c transfer function
+ * @adap:	pointer to the i2c adapter driver instance
+ * @msgs:	pointer to the i2c message structure
+ * @num:	the number of messages to transfer
+ *
+ * Initiates the send/recv activity based on the transfer message received.
+ *
+ * Return: number of msgs processed on success, negative error otherwise
+ */
+static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+				int num)
+{
+	int ret;
+	struct cdns_i2c *id = adap->algo_data;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	bool change_role = false;
+#endif
 
-out:
+	ret = pm_runtime_resume_and_get(id->dev);
+	if (ret < 0)
+		return ret;
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	/* Check i2c operating mode and switch if possible */
+	if (id->dev_mode == CDNS_I2C_MODE_SLAVE) {
+		if (id->slave_state != CDNS_I2C_SLAVE_STATE_IDLE) {
+			ret = -EAGAIN;
+			goto out;
+		}
+
+		/* Set mode to master */
+		cdns_i2c_set_mode(CDNS_I2C_MODE_MASTER, id);
+
+		/* Mark flag to change role once xfer is completed */
+		change_role = true;
+	}
+#endif
 
+	ret = cdns_i2c_master_common_xfer(adap, msgs, num);
+	if (!ret)
+		ret = num;
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
+out:
 	/* Switch i2c mode to slave */
 	if (change_role)
 		cdns_i2c_set_mode(CDNS_I2C_MODE_SLAVE, id);
-- 
2.25.1