linux-kernel - Re: [PATCH 1/2] irqchip: imx-intmux: add system PM support

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Message-ID: <364c4a4dc83618f937169ce07e6a6908@kernel.org>
Date:   Fri, 17 Jul 2020 09:41:56 +0100
From:   Marc Zyngier <maz@...nel.org>
To:     Joakim Zhang <qiangqing.zhang@....com>
Cc:     tglx@...utronix.de, jason@...edaemon.net, shawnguo@...nel.org,
        s.hauer@...gutronix.de, kernel@...gutronix.de, festevam@...il.com,
        linux-imx@....com, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.or
Subject: Re: [PATCH 1/2] irqchip: imx-intmux: add system PM support

On 2020-07-16 20:32, Joakim Zhang wrote:
> Add system PM support for intmux interrupt controller.

Care to be a little more descriptive?

> 
> Signed-off-by: Joakim Zhang <qiangqing.zhang@....com>
> ---
>  drivers/irqchip/irq-imx-intmux.c | 59 ++++++++++++++++++++++++++++++++
>  1 file changed, 59 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-imx-intmux.c 
> b/drivers/irqchip/irq-imx-intmux.c
> index c27577c81126..6095f76c4f0d 100644
> --- a/drivers/irqchip/irq-imx-intmux.c
> +++ b/drivers/irqchip/irq-imx-intmux.c
> @@ -70,6 +70,9 @@ struct intmux_data {
>  	void __iomem			*regs;
>  	struct clk			*ipg_clk;
>  	int				channum;
> +#ifdef CONFIG_PM
> +	unsigned int			*saved_reg;

Please use u32 for 32bit HW registers.

> +#endif
>  	struct intmux_irqchip_data	irqchip_data[];
>  };
> 
> @@ -232,6 +235,15 @@ static int imx_intmux_probe(struct platform_device 
> *pdev)
>  	data->channum = channum;
>  	raw_spin_lock_init(&data->lock);
> 
> +	if (IS_ENABLED(CONFIG_PM)) {
> +		/* save CHANIER register */
> +		data->saved_reg = devm_kzalloc(&pdev->dev,
> +					       sizeof(unsigned int) * channum,
> +					       GFP_KERNEL);
> +		if (!data->saved_reg)

Which isn't defined when !CONFIG_PM. The compiler is allowed to
bail here, and does (see the two kbuild failures).

> +			return -ENOMEM;
> +	}
> +
>  	ret = clk_prepare_enable(data->ipg_clk);
>  	if (ret) {
>  		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
> @@ -293,6 +305,53 @@ static int imx_intmux_remove(struct 
> platform_device *pdev)
>  	return 0;
>  }
> 
> +#ifdef CONFIG_PM
> +static void imx_intmux_save_regs(struct intmux_data *data)
> +{
> +	int i;
> +
> +	for (i = 0; i < data->channum; i++)
> +		data->saved_reg[i] = readl_relaxed(data->regs + CHANIER(i));
> +}
> +
> +static void imx_intmux_restore_regs(struct intmux_data *data)
> +{
> +	int i;
> +
> +	for (i = 0; i < data->channum; i++)
> +		writel_relaxed(data->saved_reg[i], data->regs + CHANIER(i));
> +}

Please move these two trivial functions into their respective callers.

> +
> +static int imx_intmux_suspend(struct device *dev)
> +{
> +	struct intmux_data *data = dev_get_drvdata(dev);
> +
> +	imx_intmux_save_regs(data);
> +	clk_disable_unprepare(data->ipg_clk);
> +
> +	return 0;
> +}
> +
> +static int imx_intmux_resume(struct device *dev)
> +{
> +	struct intmux_data *data = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = clk_prepare_enable(data->ipg_clk);
> +	if (ret) {
> +		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
> +		return ret;
> +	}
> +	imx_intmux_restore_regs(data);
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops imx_intmux_pm_ops = {
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_intmux_suspend, imx_intmux_resume)
> +};
> +
>  static const struct of_device_id imx_intmux_id[] = {
>  	{ .compatible = "fsl,imx-intmux", },
>  	{ /* sentinel */ },

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...