[PATCH 10/31] serial: mtk: add support for using dynamic baud clock souce

[Simon Glass]

Hi Weijie,

On Wed, 3 Aug 2022 at 21:36, Weijie Gao <weijie.gao at mediatek.com> wrote:
>
> The baud clock on some platform may change due to assigned-clock-parent
> set in DT. In current flow the baud clock is only retrieved during probe
> stage. If the parent of the source clock changes after probe stage, the
> setbrg will set wrong baudrate.
>
> To get the right clock rate, this patch records the baud clk struct to the
> driver's priv, and changes the driver's flow to get the clock rate before
> calling _mtk_serial_setbrg().
>
> Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
> ---
>  drivers/serial/serial_mtk.c | 72 ++++++++++++++++++++-----------------
>  1 file changed, 39 insertions(+), 33 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>

please see below

>
> diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c
> index a84f39b3fa..99cf62b8d9 100644
> --- a/drivers/serial/serial_mtk.c
> +++ b/drivers/serial/serial_mtk.c
> @@ -10,6 +10,7 @@
>  #include <common.h>
>  #include <div64.h>
>  #include <dm.h>
> +#include <dm/device_compat.h>
>  #include <errno.h>
>  #include <log.h>
>  #include <serial.h>
> @@ -72,25 +73,27 @@ struct mtk_serial_regs {
>
>  struct mtk_serial_priv {

please add a full comment for this struct

>         struct mtk_serial_regs __iomem *regs;
> -       u32 clock;
> +       struct clk clk;
> +       u32 fixed_clk_rate;
>         bool force_highspeed;
>  };
>
> -static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud)
> +static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud,
> +                              u32 clk_rate)

Why u32? Can you use uint? Generally it is better for parameters to
use natural types unless there is a good reason.

[..]

Regards,
Simon