Re: [PATCH V3] mmc: sdhci-of-dwcmshc: Use helper function devm_clk_get_enabled()

["yiyang (D)" <yiyang13@huawei.com>]

On 2023/8/24 17:13, Adrian Hunter wrote:
> On 24/08/23 11:46, Yi Yang wrote:
>> Since commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for
>> prepared and enabled clocks"), devm_clk_get() and clk_prepare_enable()
>> can now be replaced by devm_clk_get_enabled() when the driver enables
>> (and possibly prepares) the clocks for the whole lifetime of the device.
>> Moreover, it is no longer necessary to unprepare and disable the clocks
>> explicitly.
>>
>> Signed-off-by: Yi Yang <yiyang13@huawei.com>
>> ---
>> v3: Fix err check logic
>> v2: Remove clk_disable_unprepare in dwcmshc_remove()
>> ---
>>   drivers/mmc/host/sdhci-of-dwcmshc.c | 20 ++++++++------------
>>   1 file changed, 8 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
>> index 31c1892f4ecd..7e1cf78d9695 100644
>> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
>> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
>> @@ -495,19 +495,19 @@ static int dwcmshc_probe(struct platform_device *pdev)
>>   	priv = sdhci_pltfm_priv(pltfm_host);
>>   
>>   	if (dev->of_node) {
>> -		pltfm_host->clk = devm_clk_get(dev, "core");
>> +		pltfm_host->clk = devm_clk_get_enabled(dev, "core");
>>   		if (IS_ERR(pltfm_host->clk)) {
>>   			err = PTR_ERR(pltfm_host->clk);
>> -			dev_err(dev, "failed to get core clk: %d\n", err);
>> +			dev_err(dev, "failed to get or enable core clk: %d\n", err);
>>   			goto free_pltfm;
>>   		}
>> -		err = clk_prepare_enable(pltfm_host->clk);
>> -		if (err)
>> -			goto free_pltfm;
>>   
>> -		priv->bus_clk = devm_clk_get(dev, "bus");
>> -		if (!IS_ERR(priv->bus_clk))
>> -			clk_prepare_enable(priv->bus_clk);
>> +		priv->bus_clk = devm_clk_get_enabled(dev, "bus");
> 
> This should probably be devm_clk_get_enabled_optional()
> Maybe someone who knows the hardware can confirm?
> 
I don't know enough about hardware, Maybe we can wait for someone to 
confirm the change.

>> +		if (IS_ERR(priv->bus_clk)) {
>> +			err = PTR_ERR(priv->bus_clk);
>> +			dev_err(dev, "failed to get or enable bus clk: %d\n", err);
>> +			goto free_pltfm;
>> +		}
>>   	}
>>   
>>   	err = mmc_of_parse(host->mmc);
>> @@ -564,8 +564,6 @@ static int dwcmshc_probe(struct platform_device *pdev)
>>   err_setup_host:
>>   	sdhci_cleanup_host(host);
>>   err_clk:
>> -	clk_disable_unprepare(pltfm_host->clk);
>> -	clk_disable_unprepare(priv->bus_clk);
>>   	if (rk_priv)
>>   		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>>   					   rk_priv->rockchip_clks);
>> @@ -583,8 +581,6 @@ static void dwcmshc_remove(struct platform_device *pdev)
>>   
>>   	sdhci_remove_host(host, 0);
>>   
>> -	clk_disable_unprepare(pltfm_host->clk);
>> -	clk_disable_unprepare(priv->bus_clk);
>>   	if (rk_priv)
>>   		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>>   					   rk_priv->rockchip_clks);
> 
> .
> 

-- 
Yi