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authorJoakim Tjernlund <Joakim.Tjernlund@transmode.se>2009-10-13 10:12:03 +0200
committerBen Dooks <ben-linux@fluff.org>2009-11-02 23:28:47 +0000
commit45da790ebe746bb29f7e4adf806c020db6ff7755 (patch)
tree0aa6a12cb9b128dd2bde8d71466e878420bc67c0
parentdb3a3d4ef7f676501325ae9c7ce0c193c2c1b28f (diff)
i2c-mpc: Do not generate STOP after read.
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@transmode.se> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
-rw-r--r--drivers/i2c/busses/i2c-mpc.c10
1 files changed, 2 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index d325e86e3103..f627001108b8 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -365,9 +365,6 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
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 target,
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, int target,
/* 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);
}