Re: [PATCH 2/2] i2c: mt65xx: add additional clocks

From: AngeloGioacchino Del Regno  <angelogioacchino.delregno@collabora.com>
To: Daniel Golle <daniel@makrotopia.org>,
	linux-i2c@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Qii Wang <qii.wang@mediatek.com>,
	Sam Shih <sam.shih@mediatek.com>
Cc: 郭小桥 <joe@gainstrong.cn>
Subject: Re: [PATCH 2/2] i2c: mt65xx: add additional clocks
Date: Thu, 1 Jun 2023 11:18:25 +0200	[thread overview]
Message-ID: <053d4f6f-b43d-3a03-d193-437817321293@collabora.com> (raw)
In-Reply-To: <6632ce37e260f5f5cbdd0c6a5da8fe9679352aee.1685549360.git.daniel@makrotopia.org>

Il 31/05/23 18:11, Daniel Golle ha scritto:
> On MT7981 additional clocks are required when accessing I2C registers.
> Add MCK and PCK optional clocks to i2c-mt65xx driver so we don't have
> to always have them enabled, but really only if I2C is used.
> 
> Fixes: f82fd1845d309 ("i2c: mediatek: add support for MT7981 SoC")
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>

PCK and MCK should really be P=PMIC and M=MEM as far as I understand, which
means that they should effectively be CLK_PMIC and CLK_ARB.

In that case, you don't need to add new clocks to the driver, as you're using
the very same ones that the driver supports.

Cheers,
Angelo

> ---
>   drivers/i2c/busses/i2c-mt65xx.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index a43c4d77739ab..cd28cbec2b96d 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -93,6 +93,8 @@
>    * @I2C_MT65XX_CLK_DMA:  DMA clock for i2c via DMA
>    * @I2C_MT65XX_CLK_PMIC: PMIC clock for i2c from PMIC
>    * @I2C_MT65XX_CLK_ARB:  Arbitrator clock for i2c
> + * @I2C_MT65XX_CLK_MCK:  MCK clock for i2c
> + * @I2C_MT65XX_CLK_PCK:  PCK clock for i2c
>    * @I2C_MT65XX_CLK_MAX:  Number of supported clocks
>    */
>   enum i2c_mt65xx_clks {
> @@ -100,11 +102,13 @@ enum i2c_mt65xx_clks {
>   	I2C_MT65XX_CLK_DMA,
>   	I2C_MT65XX_CLK_PMIC,
>   	I2C_MT65XX_CLK_ARB,
> +	I2C_MT65XX_CLK_MCK,
> +	I2C_MT65XX_CLK_PCK,
>   	I2C_MT65XX_CLK_MAX
>   };
>   
>   static const char * const i2c_mt65xx_clk_ids[I2C_MT65XX_CLK_MAX] = {
> -	"main", "dma", "pmic", "arb"
> +	"main", "dma", "pmic", "arb", "mck", "pck"
>   };
>   
>   enum DMA_REGS_OFFSET {
> @@ -1444,6 +1448,14 @@ static int mtk_i2c_probe(struct platform_device *pdev)
>   	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk))
>   		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_ARB].clk);
>   
> +	i2c->clocks[I2C_MT65XX_CLK_MCK].clk = devm_clk_get_optional(&pdev->dev, "mck");
> +	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_MCK].clk))
> +		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_MCK].clk);
> +
> +	i2c->clocks[I2C_MT65XX_CLK_PCK].clk = devm_clk_get_optional(&pdev->dev, "pck");
> +	if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PCK].clk))
> +		return PTR_ERR(i2c->clocks[I2C_MT65XX_CLK_PCK].clk);
> +
>   	if (i2c->have_pmic) {
>   		i2c->clocks[I2C_MT65XX_CLK_PMIC].clk = devm_clk_get(&pdev->dev, "pmic");
>   		if (IS_ERR(i2c->clocks[I2C_MT65XX_CLK_PMIC].clk)) {