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

Lukasz Majewski
2020-01-28T08:36:14Z

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@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

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