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authorJoakim Tjernlund <Joakim.Tjernlund@transmode.se>2009-09-22 13:40:44 +0200
committerHeiko Schocher <hs@denx.de>2009-09-28 07:35:56 +0200
commitd1c9e5b37901b53ffc1ce3f08ec8ed61bfd557b6 (patch)
tree78182e8bca0369b4bbd625da4a41cf0c5267535e /drivers/i2c
parent99404202127346b9e91503bbd69deafa18c980c4 (diff)
downloadtalos-obmc-uboot-d1c9e5b37901b53ffc1ce3f08ec8ed61bfd557b6.tar.gz
talos-obmc-uboot-d1c9e5b37901b53ffc1ce3f08ec8ed61bfd557b6.zip
fsl_i2c: Do not generate STOP after read.
__i2c_read always ends with a STOP condition thereby releasing the bus. It is cleaner to do the STOP magic in i2c_read(), like i2c_write() does. This may also help future multimaster systems which wants to hold on to the bus until all transactions are finished. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/fsl_i2c.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
index 4d5552bcd5..2241990f94 100644
--- a/drivers/i2c/fsl_i2c.c
+++ b/drivers/i2c/fsl_i2c.c
@@ -353,9 +353,10 @@ __i2c_read(u8 *data, int length)
writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_TXAK,
&i2c_dev[i2c_bus_num]->cr);
- /* Generate stop on last byte */
+ /* Do not generate stop on last byte */
if (i == length - 1)
- writeb(I2C_CR_MEN | I2C_CR_TXAK, &i2c_dev[i2c_bus_num]->cr);
+ writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX,
+ &i2c_dev[i2c_bus_num]->cr);
data[i] = readb(&i2c_dev[i2c_bus_num]->dr);
}
@@ -378,11 +379,11 @@ i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
&& i2c_write_addr(dev, I2C_READ_BIT, 1) != 0)
i = __i2c_read(data, length);
- if (length && i2c_wait4bus()) /* Wait until STOP */
- debug("i2c_read: wait4bus timed out\n");
-
writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);
+ if (i2c_wait4bus()) /* Wait until STOP */
+ debug("i2c_read: wait4bus timed out\n");
+
if (i == length)
return 0;
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