[PATCH 14/20] serial_lpuart: add clock enable if CONFIG_CLK is defined

[Giulio Benetti]

Hi Lukasz and all,

On 12/10/19 12:48 AM, Lukasz Majewski wrote:
> On Mon, 9 Dec 2019 16:20:10 +0100
> Giulio Benetti <giulio.benetti at benettiengineering.com> wrote:
> 
>> Hi Lukasz,
>>
>> On 12/8/19 3:52 PM, Lukasz Majewski wrote:
>>> On Wed,  4 Dec 2019 18:44:33 +0100
>>> Giulio Benetti <giulio.benetti at benettiengineering.com> wrote:
>>>    
>>>> 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.
>>>>
>>>> Signed-off-by: Giulio Benetti
>>>> <giulio.benetti at benettiengineering.com> ---
>>>>    drivers/serial/serial_lpuart.c | 13 +++++++++++++
>>>>    1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/drivers/serial/serial_lpuart.c
>>>> b/drivers/serial/serial_lpuart.c index 4b0a964d1b..52bd2baf7d
>>>> 100644 --- a/drivers/serial/serial_lpuart.c
>>>> +++ b/drivers/serial/serial_lpuart.c
>>>> @@ -483,6 +483,19 @@ 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);

While adding support for OF_PLATDATA, I've realized that when using 
OF_PLATDATA I can only use clk_get_by_index_platdata() but often imx 
peripheral drivers(as done in Linux) get clock by name("per" clock) 
instead of other clock sources. So here the problem is that I can't know 
for sure which id "per" clock source will have. I wouldn't use 0 as 
default clock-id since it's not sure "per" will be the 0 index.
And this will occur for fsl_esdhc_imx.c driver too.

Do you have any suggestions?

Thanks in advance

Best regards
-- 
Giulio Benetti
Benetti Engineering sas