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[5.4,111/214] i2c: rcar: in slave mode, clear NACK earlier

Message ID 20200901150958.301557647@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Sept. 1, 2020, 3:09 p.m. UTC 
From: Wolfram Sang <wsa+renesas@sang-engineering.com>

[ Upstream commit 914a7b3563b8fb92f976619bbd0fa3a4a708baae ]

Currently, a NACK in slave mode is set/cleared when SCL is held low by
the IP core right before the bit is about to be pushed out. This is too
late for clearing and then a NACK from the previous byte is still used
for the current one. Now, let's clear the NACK right after we detected
the STOP condition following the NACK.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-rcar.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 0b90aa0318df3..9c162a01a5849 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -587,6 +587,7 @@  static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
 	/* master sent stop */
 	if (ssr_filtered & SSR) {
 		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
+		rcar_i2c_write(priv, ICSCR, SIE | SDBS); /* clear our NACK */
 		rcar_i2c_write(priv, ICSIER, SAR);
 		rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
 	}