linux-kernel - RE: [PATCH 02/11] i2c: imx-lpi2c: add runtime pm support

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Message-ID: <AM6PR04MB496648409D86D673355B9DAC80689@AM6PR04MB4966.eurprd04.prod.outlook.com>
Date:   Fri, 19 Mar 2021 04:40:09 +0000
From:   Aisheng Dong <aisheng.dong@....com>
To:     Clark Wang <xiaoning.wang@....com>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>
CC:     "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        "sumit.semwal@...aro.org" <sumit.semwal@...aro.org>,
        "christian.koenig@....com" <christian.koenig@....com>,
        "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 02/11] i2c: imx-lpi2c: add runtime pm support

> From: Clark Wang <xiaoning.wang@....com>
> Sent: Wednesday, March 17, 2021 2:54 PM
> Subject: [PATCH 02/11] i2c: imx-lpi2c: add runtime pm support
> 
> - Add runtime pm support to dynamicly manage the clock.
> - Put the suspend to suspend_noirq.
> - Call .pm_runtime_force_suspend() to force runtime pm suspended
>   in .suspend_noirq().
> 

The patch title needs to be improved as the driver already supports rpm.
And do one thing in one patch.

> Signed-off-by: Fugang Duan <fugang.duan@....com>
> Signed-off-by: Gao Pan <pandy.gao@....com>
> Reviewed-by: Anson Huang <Anson.Huang@....com>

Please add your sign-off.

> ---
>  drivers/i2c/busses/i2c-imx-lpi2c.c | 50 ++++++++++++++++++++----------
>  1 file changed, 33 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c
> b/drivers/i2c/busses/i2c-imx-lpi2c.c
> index bbf44ac95021..1e920e7ac7c1 100644
> --- a/drivers/i2c/busses/i2c-imx-lpi2c.c
> +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
> @@ -574,7 +574,8 @@ static int lpi2c_imx_probe(struct platform_device
> *pdev)
>  	if (ret)
>  		lpi2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
> 
> -	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
> +	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr,
> +			       IRQF_NO_SUSPEND,

This belongs to a separate patch

>  			       pdev->name, lpi2c_imx);
>  	if (ret) {
>  		dev_err(&pdev->dev, "can't claim irq %d\n", irq); @@ -584,35
> +585,32 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
>  	i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
>  	platform_set_drvdata(pdev, lpi2c_imx);
> 
> -	ret = clk_prepare_enable(lpi2c_imx->clk);
> -	if (ret) {
> -		dev_err(&pdev->dev, "clk enable failed %d\n", ret);
> -		return ret;
> -	}
> -
>  	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
>  	pm_runtime_use_autosuspend(&pdev->dev);
> -	pm_runtime_get_noresume(&pdev->dev);
> -	pm_runtime_set_active(&pdev->dev);
>  	pm_runtime_enable(&pdev->dev);
> 
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (ret < 0) {
> +		pm_runtime_put_noidle(&pdev->dev);
> +		dev_err(&pdev->dev, "failed to enable clock\n");
> +		return ret;
> +	}

Can't current clk control via rpm work well?
Please describe why need change.

> +
>  	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
>  	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
>  	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
> 
> +	pm_runtime_put(&pdev->dev);
> +
>  	ret = i2c_add_adapter(&lpi2c_imx->adapter);
>  	if (ret)
>  		goto rpm_disable;
> 
> -	pm_runtime_mark_last_busy(&pdev->dev);
> -	pm_runtime_put_autosuspend(&pdev->dev);
> -
>  	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
> 
>  	return 0;
> 
>  rpm_disable:
> -	pm_runtime_put(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  	pm_runtime_dont_use_autosuspend(&pdev->dev);
> 
> @@ -636,7 +634,7 @@ static int __maybe_unused
> lpi2c_runtime_suspend(struct device *dev)
>  	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
> 
>  	clk_disable_unprepare(lpi2c_imx->clk);
> -	pinctrl_pm_select_sleep_state(dev);
> +	pinctrl_pm_select_idle_state(dev);

This belongs to a separate patch

> 
>  	return 0;
>  }
> @@ -649,16 +647,34 @@ static int __maybe_unused
> lpi2c_runtime_resume(struct device *dev)
>  	pinctrl_pm_select_default_state(dev);
>  	ret = clk_prepare_enable(lpi2c_imx->clk);
>  	if (ret) {
> -		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
> +		dev_err(dev, "can't enable I2C clock, ret=%d\n", ret);

Probably unnecessary change

>  		return ret;
>  	}
> 
> +	return ret;
> +}
> +
> +static int lpi2c_suspend_noirq(struct device *dev) {
> +	int ret;
> +
> +	ret = pm_runtime_force_suspend(dev);
> +	if (ret)
> +		return ret;
> +
> +	pinctrl_pm_select_sleep_state(dev);
> +
>  	return 0;
>  }
> 
> +static int lpi2c_resume_noirq(struct device *dev) {
> +	return pm_runtime_force_resume(dev);
> +}
> +
>  static const struct dev_pm_ops lpi2c_pm_ops = {
> -	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> -				      pm_runtime_force_resume)
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(lpi2c_suspend_noirq,
> +				     lpi2c_resume_noirq)

Belongs to separate change and explain why need do this

>  	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
>  			   lpi2c_runtime_resume, NULL)
>  };
> --
> 2.25.1