linux-kernel - Re: [PATCH v1 2/3] spi: cadence-quadspi: Add clock configuration for StarFive JH7110 QSPI

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Date:   Thu, 1 Jun 2023 09:52:38 +0800
From:   William Qiu <william.qiu@...rfivetech.com>
To:     Mark Brown <broonie@...nel.org>
CC:     <devicetree@...r.kernel.org>, <linux-spi@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linux-riscv@...ts.infradead.org>,
        "Rob Herring" <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        "Emil Renner Berthing" <kernel@...il.dk>,
        Ziv Xu <ziv.xu@...rfivetech.com>
Subject: Re: [PATCH v1 2/3] spi: cadence-quadspi: Add clock configuration for
 StarFive JH7110 QSPI



On 2023/5/31 21:20, Mark Brown wrote:
> On Wed, May 31, 2023 at 02:19:16PM +0800, William Qiu wrote:
>> On 2023/5/30 18:33, Mark Brown wrote:
> 
>> > You could always specify a different array of clocks depending on which
>> > compatible the driver sees, just like you'd conditionally request clocks
>> > individually.
> 
>> 	If specify a different array of clocks depending on which compatible
>> the driver sees, since there will also be clock operations in the suspend
>> and resume interfaces, this can make the code look complicated.
> 
> If you store the clock count and array in the driver data that should be
> fairly simple I think.
> 
>> 	as following:
> 
>> 	/* Obtain QSPI clock. */
>> 	cqspi->num_clks = devm_clk_bulk_get_all(dev, &cqspi->clks);
>> 	if (cqspi->num_clks < 0) {
>> 		dev_err(dev, "Cannot claim QSPI clock: %u\n", cqspi->num_clks);
>> 		return -EINVAL;
>> 	}
> 
>> 	This way, the code will look simpler and clearer. How do you think
>> about it.
> 
> I'm not clear how enable and disable would then work?

enable use this API:
clk_bulk_prepare_enable(dev->num_clks, dev->clks);

then disable:
clk_bulk_disable_unprepare(dev->num_clks, dev->clks);

But I'll first try specify a different array of clocks depending on which
compatible the driver sees first.

Best regards,
William