[PATCH v2 15/21] serial_lpuart: add clock enable if CONFIG_CLK is defined

Lukasz Majewski lukma at denx.de
Tue Jan 28 09:36:14 CET 2020


Hi Giulio,

> This driver assumes that lpuart clock is already enabled before
> probing but using DM only lpuart won't be automatically enabled so add
> clk_enable() when probing if CONFIG_CLK is defined. If clock is not
> found, because DM is not used, let's emit a warning and proceed,
> because serial clock could also be already enabled by non DM code. If
> clock is found but cna't be enabled then return with error.
		     ^^^^ - can't

> 
> Signed-off-by: Giulio Benetti <giulio.benetti at benettiengineering.com>
> ---
> V1->V2:
> * moved error as warning if clk not found
> ---
>  drivers/serial/serial_lpuart.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/serial/serial_lpuart.c
> b/drivers/serial/serial_lpuart.c index 4b0a964d1b..b2ec56172e 100644
> --- a/drivers/serial/serial_lpuart.c
> +++ b/drivers/serial/serial_lpuart.c
> @@ -483,6 +483,22 @@ static int lpuart_serial_pending(struct udevice
> *dev, bool input) 
>  static int lpuart_serial_probe(struct udevice *dev)
>  {
> +#if CONFIG_IS_ENABLED(CLK)
> +	struct clk per_clk;
> +	int ret;
> +
> +	ret = clk_get_by_name(dev, "per", &per_clk);
> +	if (!ret) {
> +		ret = clk_enable(&per_clk);
> +		if (ret) {
> +			dev_err(dev, "Failed to get per clk: %d\n",
> ret);
> +			return ret;
> +		}
> +	} else {
> +		dev_warn(dev, "Failed to get per clk: %d\n",  ret);
		^^^^^^ - please change to debug() as some devices may
		enable CONFIG_CLK, but did not yet support (have
		implemented) this clock in CCF.

> +	}
> +#endif
> +
>  	if (is_lpuart32(dev))
>  		return _lpuart32_serial_init(dev);
>  	else




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
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