linux-kernel - Re: [PATCH] i3c: master: cdns: Simplify handling clocks in probe()

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Message-ID: <f9157fbf-09a1-41e5-b5f2-902ca20b870d@linaro.org>
Date: Mon, 14 Jul 2025 16:40:53 +0200
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Frank Li <Frank.li@....com>
Cc: Przemysław Gaj <pgaj@...ence.com>,
 Alexandre Belloni <alexandre.belloni@...tlin.com>,
 linux-i3c@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] i3c: master: cdns: Simplify handling clocks in probe()

On 14/07/2025 16:15, Frank Li wrote:
> On Sun, Jul 13, 2025 at 05:24:12PM +0200, Krzysztof Kozlowski wrote:
>> The two clocks, driver is getting, are not being disabled/re-enabled
>> during runtime of the device.  Eliminate one variable in state struct,
>> all error paths and a lot of code from probe() and remove() by using
>> devm_clk_get_enabled().
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
>> ---
>>  drivers/i3c/master/i3c-master-cdns.c | 51 +++++++---------------------
>>  1 file changed, 12 insertions(+), 39 deletions(-)
>>
>> diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
>> index 449e85d7ba87..cc504b58013a 100644
>> --- a/drivers/i3c/master/i3c-master-cdns.c
>> +++ b/drivers/i3c/master/i3c-master-cdns.c
>> @@ -412,7 +412,6 @@ struct cdns_i3c_master {
>>  	} xferqueue;
>>  	void __iomem *regs;
>>  	struct clk *sysclk;
>> -	struct clk *pclk;
>>  	struct cdns_i3c_master_caps caps;
>>  	unsigned long i3c_scl_lim;
>>  	const struct cdns_i3c_data *devdata;
>> @@ -1566,6 +1565,7 @@ MODULE_DEVICE_TABLE(of, cdns_i3c_master_of_ids);
>>  static int cdns_i3c_master_probe(struct platform_device *pdev)
>>  {
>>  	struct cdns_i3c_master *master;
>> +	struct clk *pclk;
>>  	int ret, irq;
>>  	u32 val;
>>
>> @@ -1581,11 +1581,11 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
>>  	if (IS_ERR(master->regs))
>>  		return PTR_ERR(master->regs);
>>
>> -	master->pclk = devm_clk_get(&pdev->dev, "pclk");
>> -	if (IS_ERR(master->pclk))
>> -		return PTR_ERR(master->pclk);
>> +	pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
>> +	if (IS_ERR(pclk))
>> +		return PTR_ERR(pclk);
>>
>> -	master->sysclk = devm_clk_get(&pdev->dev, "sysclk");
>> +	master->sysclk = devm_clk_get_enabled(&pdev->dev, "sysclk");
> 
> Can you use devm_clk_bulk_get_all_enabled() to simpilfy futher?

Instead of asking redundant question check yourself. On a first glance
it cannot, because it won't be simpler - you still need individual
clock. But if you find it possible which is not visible on first glance,
make a proposal instead of just random drive by comments.

Best regards,
Krzysztof