linux-kernel - [PATCH 32/33] i2c: fsi: Add boolean for skip stop command on abort

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Date: Thu, 15 Feb 2024 16:07:58 -0600
From: Eddie James <eajames@...ux.ibm.com>
To: linux-fsi@...ts.ozlabs.org
Cc: linux-kernel@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-clk@...r.kernel.org, devicetree@...r.kernel.org,
        andi.shyti@...nel.org, eajames@...ux.ibm.com, alistair@...ple.id.au,
        joel@....id.au, jk@...abs.org, sboyd@...nel.org,
        mturquette@...libre.com, robh@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org
Subject: [PATCH 32/33] i2c: fsi: Add boolean for skip stop command on abort

In preparation for interrupt support, store whether to skip the
final stop command during the abort procedure instead of checking
the previously read status register in the abort function.

Signed-off-by: Eddie James <eajames@...ux.ibm.com>
---
 drivers/i2c/busses/i2c-fsi.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
index 5f524fb6f0f8..33f4e64cb60b 100644
--- a/drivers/i2c/busses/i2c-fsi.c
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -116,6 +116,9 @@
 #define I2C_STAT_ANY_RESP	(I2C_STAT_ERR |				\
 				 I2C_STAT_DAT_REQ |			\
 				 I2C_STAT_CMD_COMP)
+#define I2C_STAT_SKIP_STOP	(I2C_STAT_PARITY |			\
+				 I2C_STAT_LOST_ARB |			\
+				 I2C_STAT_STOP_ERR)
 
 /* extended status register */
 #define I2C_ESTAT_FIFO_SZ	GENMASK(31, 24)
@@ -150,6 +153,7 @@ struct fsi_i2c_master {
 	struct mutex		lock;
 	u32			clock_div;
 	u8			fifo_size;
+	bool			skip_stop;
 };
 
 struct fsi_i2c_port {
@@ -459,31 +463,30 @@ static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port)
 	return 0;
 }
 
-static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
+static int fsi_i2c_abort(struct fsi_i2c_port *port)
 {
 	struct fsi_i2c_master *i2c = port->master;
 	u32 cmd = I2C_CMD_WITH_STOP;
 	unsigned long start;
-	u32 stat;
+	u32 status;
 	int rc;
 
 	rc = fsi_i2c_reset_engine(i2c, port->port);
 	if (rc)
 		return rc;
 
-	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &status);
 	if (rc)
 		return rc;
 
 	/* if sda is low, peform full bus reset */
-	if (!(stat & I2C_STAT_SDA_IN)) {
+	if (!(status & I2C_STAT_SDA_IN)) {
 		rc = fsi_i2c_reset_bus(i2c, port);
 		if (rc)
 			return rc;
 	}
 
-	/* skip final stop command for these errors */
-	if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR))
+	if (i2c->skip_stop)
 		return 0;
 
 	/* write stop command */
@@ -534,7 +537,8 @@ static int fsi_i2c_handle_status(struct fsi_i2c_port *port,
 	int rc;
 
 	if (status & I2C_STAT_ERR) {
-		rc = fsi_i2c_abort(port, status);
+		port->master->skip_stop = status & I2C_STAT_SKIP_STOP;
+		rc = fsi_i2c_abort(port);
 		if (rc)
 			return rc;
 
-- 
2.39.3