On Thu, Nov 02, 2023 at 10:53:54AM +0800, Hans Hu wrote:
> These Settings for the same register, REG_CR,
> can be put together to reduce code redundancy.
>
> Signed-off-by: Hans Hu <hanshu-oc@xxxxxxxxxxx>
Some registers require that you first write a certain value, and only
then can write another value. Have you double checked with datasheets
that these register writes can safely be aggregated?
> ---
> drivers/i2c/busses/i2c-wmt.c | 35 +++++++++--------------------------
> 1 file changed, 9 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-wmt.c b/drivers/i2c/busses/i2c-wmt.c
> index a44ce5fdde8a..d503e85752ea 100644
> --- a/drivers/i2c/busses/i2c-wmt.c
> +++ b/drivers/i2c/busses/i2c-wmt.c
> @@ -144,9 +144,6 @@ static int wmt_i2c_write(struct i2c_adapter *adap, struct i2c_msg *pmsg,
> if (!(pmsg->flags & I2C_M_NOSTART)) {
> val = readw(i2c_dev->base + REG_CR);
> val &= ~CR_TX_END;
> - writew(val, i2c_dev->base + REG_CR);
> -
> - val = readw(i2c_dev->base + REG_CR);
> val |= CR_CPU_RDY;
> writew(val, i2c_dev->base + REG_CR);
> }
> @@ -204,24 +201,15 @@ static int wmt_i2c_read(struct i2c_adapter *adap, struct i2c_msg *pmsg,
> u32 xfer_len = 0;
>
> val = readw(i2c_dev->base + REG_CR);
> - val &= ~CR_TX_END;
> - writew(val, i2c_dev->base + REG_CR);
> + val &= ~(CR_TX_END | CR_TX_NEXT_NO_ACK);
>
> - val = readw(i2c_dev->base + REG_CR);
> - val &= ~CR_TX_NEXT_NO_ACK;
> - writew(val, i2c_dev->base + REG_CR);
> -
> - if (!(pmsg->flags & I2C_M_NOSTART)) {
> - val = readw(i2c_dev->base + REG_CR);
> + if (!(pmsg->flags & I2C_M_NOSTART))
> val |= CR_CPU_RDY;
> - writew(val, i2c_dev->base + REG_CR);
> - }
>
> - if (pmsg->len == 1) {
> - val = readw(i2c_dev->base + REG_CR);
> + if (pmsg->len == 1)
> val |= CR_TX_NEXT_NO_ACK;
> - writew(val, i2c_dev->base + REG_CR);
> - }
> +
> + writew(val, i2c_dev->base + REG_CR);
>
> reinit_completion(&i2c_dev->complete);
>
> @@ -243,15 +231,10 @@ static int wmt_i2c_read(struct i2c_adapter *adap, struct i2c_msg *pmsg,
> pmsg->buf[xfer_len] = readw(i2c_dev->base + REG_CDR) >> 8;
> xfer_len++;
>
> - if (xfer_len == pmsg->len - 1) {
> - val = readw(i2c_dev->base + REG_CR);
> - val |= (CR_TX_NEXT_NO_ACK | CR_CPU_RDY);
> - writew(val, i2c_dev->base + REG_CR);
> - } else {
> - val = readw(i2c_dev->base + REG_CR);
> - val |= CR_CPU_RDY;
> - writew(val, i2c_dev->base + REG_CR);
> - }
> + val = readw(i2c_dev->base + REG_CR) | CR_CPU_RDY;
> + if (xfer_len == pmsg->len - 1)
> + val |= CR_TX_NEXT_NO_ACK;
> + writew(val, i2c_dev->base + REG_CR);
> }
>
> return 0;
> --
> 2.34.1
>
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