Hi Lee,
On 06/11/25 6:32 pm, Lee Jones wrote:
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>
> On Wed, 22 Oct 2025, Manikandan Muralidharan wrote:
>
>> The XLCDC IP supports parallel RGB, MIPI DSI and LVDS Display.
>> The LCD Generic clock (sys_clk) is used for Parallel RGB and MIPI
>> displays, while the LVDS PLL clock (lvds_pll_clk) is used for LVDS
>> displays.Since both the clocks cannot co-exist together in the DT
>> for a given display, this patch first attempts to retrieve sys_clk
>> If that fails,it then tries to acquire lvds_pll_clk.
>>
>> Signed-off-by: Manikandan Muralidharan <[email protected]>
>> Signed-off-by: Dharma Balasubiramani <[email protected]>
>> ---
>> changes in v2:
>> - Rephrase the comments, commit message and err logs
>> - Replace dev_err wwith dev_warn
>> - Remove Initializing sys_clk and lvds_pll_clk to NULL post
>> devm_kzalloc() call
>>
>> ---
>> drivers/mfd/atmel-hlcdc.c | 16 ++++++++++++++--
>> include/linux/mfd/atmel-hlcdc.h | 1 +
>> 2 files changed, 15 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
>> index 4c4e35d404f3..f680392b01ba 100644
>> --- a/drivers/mfd/atmel-hlcdc.c
>> +++ b/drivers/mfd/atmel-hlcdc.c
>> @@ -108,10 +108,22 @@ static int atmel_hlcdc_probe(struct platform_device
>> *pdev)
>> return PTR_ERR(hlcdc->periph_clk);
>> }
>>
>> + /*
>> + * Retrieve any one of the Main clk required by the LCD to operate:
>> + *
>> + * LCDC Generic Clock (sys_clk) - Parallel RGB and MIPI displays,
>> + * LVDS PLL (lvds_pll_clk) - LVDS display
>> + */
>> hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
>> if (IS_ERR(hlcdc->sys_clk)) {
>> - dev_err(dev, "failed to get system clock\n");
>> - return PTR_ERR(hlcdc->sys_clk);
>> + dev_warn(dev,
>> + "failed to get LCDC generic clock, trying for LVDS
>> PLL clock instead\n");
>
> Does the user really care which clock they use?
>
> Can this just happen silently instead?
>
>> + hlcdc->lvds_pll_clk = devm_clk_get(dev, "lvds_pll_clk");
>> + if (IS_ERR(hlcdc->lvds_pll_clk)) {
>> + dev_err(dev, "failed to get LVDS PLL clock\n");
>
> Failed to obtain both the LCDC (generic) and LVDS PLL clocks
>
Thankyou, I will make sure v3 addresses these comments.
>> + return PTR_ERR(hlcdc->lvds_pll_clk);
>> + }
>> }
>>
>> hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
>> diff --git a/include/linux/mfd/atmel-hlcdc.h
>> b/include/linux/mfd/atmel-hlcdc.h
>> index 80d675a03b39..07c2081867fd 100644
>> --- a/include/linux/mfd/atmel-hlcdc.h
>> +++ b/include/linux/mfd/atmel-hlcdc.h
>> @@ -75,6 +75,7 @@
>> */
>> struct atmel_hlcdc {
>> struct regmap *regmap;
>> + struct clk *lvds_pll_clk;
>> struct clk *periph_clk;
>> struct clk *sys_clk;
>> struct clk *slow_clk;
>> --
>> 2.25.1
>>
>
> --
> Lee Jones [李琼斯]
--
Thanks and Regards,
Manikandan M.
