Commit 21f4cbb7 authored by Joakim Tjernlund's avatar Joakim Tjernlund Committed by Heiko Schocher
Browse files

fsl_i2c: Wait for STOP condition to propagate

After issuing a STOP one must wait until the STOP has completed
on the bus before doing something new to the controller.

Also add an extra read of SR as the manual mentions doing that
is a good idea.

Remove surplus write of CR just before a write, isn't required and
could potentially disturb the I2C bus.
Signed-off-by: default avatarJoakim Tjernlund <>
parent 984f10ba
......@@ -223,7 +223,7 @@ i2c_init(int speed, int slaveadd)
static __inline__ int
static int
unsigned long long timeval = get_ticks();
......@@ -248,6 +248,8 @@ i2c_wait(int write)
csr = readb(&i2c_dev[i2c_bus_num]->sr);
if (!(csr & I2C_SR_MIF))
/* Read again to allow register to stabilise */
csr = readb(&i2c_dev[i2c_bus_num]->sr);
writeb(0x0, &i2c_dev[i2c_bus_num]->sr);
......@@ -293,9 +295,6 @@ __i2c_write(u8 *data, int length)
int i;
writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX,
for (i = 0; i < length; i++) {
writeb(data[i], &i2c_dev[i2c_bus_num]->dr);
......@@ -351,6 +350,9 @@ 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 (i == length)
......@@ -372,6 +374,8 @@ i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
writeb(I2C_CR_MEN, &i2c_dev[i2c_bus_num]->cr);
if (i2c_wait4bus()) /* Wait until STOP */
debug("i2c_write: wait4bus timed out\n");
if (i == length)
return 0;
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