[PATCH v3] i2c: busses: Use min() to improve code
Jonathan Cameron
Jonathan.Cameron at huawei.com
Tue Jul 8 04:06:58 PDT 2025
On Tue, 8 Jul 2025 11:15:20 +0800
Qianfeng Rong <rongqianfeng at vivo.com> wrote:
> Use min() to reduce the code and improve its readability.
>
> The type of the max parameter in the st_i2c_rd_fill_tx_fifo()
> was changed from int to u32, because the max parameter passed
> in is always greater than 0.
>
> Signed-off-by: Qianfeng Rong <rongqianfeng at vivo.com>
> Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>
> ---
> v2-> v3:
> - added the <linux/minmax.h> as suggested by Jonathan.
> - used i = min(...) as the loop initializer according
> to Jonathan.
>
> v1-> v2:
> - Change the max parameter type in st_i2c_rd_fill_tx_fifo()
> from int to u32
> ---
> drivers/i2c/busses/i2c-st.c | 19 ++++++-------------
> 1 file changed, 6 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-st.c b/drivers/i2c/busses/i2c-st.c
> index 750fff3d2389..e4b2ed8a9264 100644
> --- a/drivers/i2c/busses/i2c-st.c
> +++ b/drivers/i2c/busses/i2c-st.c
> @@ -19,6 +19,7 @@
> #include <linux/of.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/platform_device.h>
> +#include <linux/minmax.h>
>
> /* SSC registers */
> #define SSC_BRG 0x000
> @@ -422,12 +423,8 @@ static void st_i2c_wr_fill_tx_fifo(struct st_i2c_dev *i2c_dev)
> tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT);
> tx_fstat &= SSC_TX_FSTAT_STATUS;
>
> - if (c->count < (SSC_TXFIFO_SIZE - tx_fstat))
> - i = c->count;
> - else
> - i = SSC_TXFIFO_SIZE - tx_fstat;
> -
> - for (; i > 0; i--, c->count--, c->buf++)
> + for (i = min(c->count, SSC_TXFIFO_SIZE - tx_fstat);
> + i > 0; i--, c->count--, c->buf++)
for (i = min(c->count, SSC_TXFIFO_SIZE - tx_fstat);
i > 0; i--, c->count--, c->buf++)
st_i2c_write_tx_fifo(i2c_dev, *c->buf);
So different alignment form what you have.
> st_i2c_write_tx_fifo(i2c_dev, *c->buf);
> }
>
> @@ -439,7 +436,7 @@ static void st_i2c_wr_fill_tx_fifo(struct st_i2c_dev *i2c_dev)
> * This functions fills the Tx FIFO with fixed pattern when
> * in read mode to trigger clock.
> */
> -static void st_i2c_rd_fill_tx_fifo(struct st_i2c_dev *i2c_dev, int max)
> +static void st_i2c_rd_fill_tx_fifo(struct st_i2c_dev *i2c_dev, u32 max)
> {
> struct st_i2c_client *c = &i2c_dev->client;
> u32 tx_fstat, sta;
> @@ -452,12 +449,8 @@ static void st_i2c_rd_fill_tx_fifo(struct st_i2c_dev *i2c_dev, int max)
> tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT);
> tx_fstat &= SSC_TX_FSTAT_STATUS;
>
> - if (max < (SSC_TXFIFO_SIZE - tx_fstat))
> - i = max;
> - else
> - i = SSC_TXFIFO_SIZE - tx_fstat;
> -
> - for (; i > 0; i--, c->xfered++)
> + for (i = min(max, SSC_TXFIFO_SIZE - tx_fstat);
> + i > 0; i--, c->xfered++)
> st_i2c_write_tx_fifo(i2c_dev, 0xff);
> }
>
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