[U-Boot] [PATCH 04/24] mxc_i2c: clear i2sr before waiting for bit

Marek Vasut
2012-06-22T16:59:11Z

Dear Troy Kisky,

> Let's clear the sr register before waiting for
> bit to be set, instead of clearing it after
> hardware sets it. No real operational difference here,
> but allows combining of i2c_imx_trx_complete and
> i2c_imx_bus_busy in later patches.
>
> Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
> ---
> drivers/i2c/mxc_i2c.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
> index 0fd508a..bae9335 100644
> --- a/drivers/i2c/mxc_i2c.c
> +++ b/drivers/i2c/mxc_i2c.c
> @@ -200,10 +200,8 @@ int i2c_imx_trx_complete(void)
> int timeout = I2C_MAX_TIMEOUT;
>
> while (timeout--) {
> - if (readb(&i2c_regs->i2sr) & I2SR_IIF) {
> - writeb(0, &i2c_regs->i2sr);
> + if (readb(&i2c_regs->i2sr) & I2SR_IIF)
> return 0;
> - }
>
> udelay(1);
> }
> @@ -215,6 +213,7 @@ static int tx_byte(struct mxc_i2c_regs *i2c_regs, u8
> byte) {
> unsigned ret;
>
> + writeb(0, &i2c_regs->i2sr);
> writeb(byte, &i2c_regs->i2dr);
> ret = i2c_imx_trx_complete();
> if (ret < 0)

If you could try this on mx51 and mx31, I'd be glad. I recall having some issues
there.

If it works, add
Acked-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut