The patch titled
i2c-mpc: do not generate STOP after read
has been removed from the -mm tree. Its filename was
i2c-mpc-do-not-generate-stop-after-read.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: i2c-mpc: do not generate STOP after read
From: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
The driver always ends a read with a STOP condition which breaks
subsequent I2C reads/writes in the same transaction as these expect to do
a repeated START(ReSTART).
This will also help I2C multimaster as the bus will not be released after
the first read, but when the whole transaction ends.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@xxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Ben Dooks <ben-linux@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN drivers/i2c/busses/i2c-mpc.c~i2c-mpc-do-not-generate-stop-after-read drivers/i2c/busses/i2c-mpc.c
--- a/drivers/i2c/busses/i2c-mpc.c~i2c-mpc-do-not-generate-stop-after-read
+++ a/drivers/i2c/busses/i2c-mpc.c
@@ -365,9 +365,6 @@ static int mpc_write(struct mpc_i2c *i2c
unsigned timeout = i2c->adap.timeout;
u32 flags = restart ? CCR_RSTA : 0;
- /* Start with MEN */
- if (!restart)
- writeccr(i2c, CCR_MEN);
/* Start as master */
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
/* Write target byte */
@@ -396,9 +393,6 @@ static int mpc_read(struct mpc_i2c *i2c,
int i, result;
u32 flags = restart ? CCR_RSTA : 0;
- /* Start with MEN */
- if (!restart)
- writeccr(i2c, CCR_MEN);
/* Switch to read - restart */
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
/* Write target address byte - this time with the read flag set */
@@ -425,9 +419,9 @@ static int mpc_read(struct mpc_i2c *i2c,
/* Generate txack on next to last byte */
if (i == length - 2)
writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
- /* Generate stop on last byte */
+ /* Do not generate stop on last byte */
if (i == length - 1)
- writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK);
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
data[i] = readb(i2c->base + MPC_I2C_DR);
}
_
Patches currently in -mm which might be from Joakim.Tjernlund@xxxxxxxxxxxx are
origin.patch
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