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

[Frank Li <Frank.li@nxp.com>]

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@linaro.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?

Frank

>  	if (IS_ERR(master->sysclk))
>  		return PTR_ERR(master->sysclk);
>
> @@ -1593,18 +1593,8 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
>  	if (irq < 0)
>  		return irq;
>
> -	ret = clk_prepare_enable(master->pclk);
> -	if (ret)
> -		return ret;
> -
> -	ret = clk_prepare_enable(master->sysclk);
> -	if (ret)
> -		goto err_disable_pclk;
> -
> -	if (readl(master->regs + DEV_ID) != DEV_ID_I3C_MASTER) {
> -		ret = -EINVAL;
> -		goto err_disable_sysclk;
> -	}
> +	if (readl(master->regs + DEV_ID) != DEV_ID_I3C_MASTER)
> +		return -EINVAL;
>
>  	spin_lock_init(&master->xferqueue.lock);
>  	INIT_LIST_HEAD(&master->xferqueue.list);
> @@ -1615,7 +1605,7 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
>  	ret = devm_request_irq(&pdev->dev, irq, cdns_i3c_master_interrupt, 0,
>  			       dev_name(&pdev->dev), master);
>  	if (ret)
> -		goto err_disable_sysclk;
> +		return ret;
>
>  	platform_set_drvdata(pdev, master);
>
> @@ -1637,29 +1627,15 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
>  	master->ibi.slots = devm_kcalloc(&pdev->dev, master->ibi.num_slots,
>  					 sizeof(*master->ibi.slots),
>  					 GFP_KERNEL);
> -	if (!master->ibi.slots) {
> -		ret = -ENOMEM;
> -		goto err_disable_sysclk;
> -	}
> +	if (!master->ibi.slots)
> +		return -ENOMEM;
>
>  	writel(IBIR_THR(1), master->regs + CMD_IBI_THR_CTRL);
>  	writel(MST_INT_IBIR_THR, master->regs + MST_IER);
>  	writel(DEVS_CTRL_DEV_CLR_ALL, master->regs + DEVS_CTRL);
>
> -	ret = i3c_master_register(&master->base, &pdev->dev,
> -				  &cdns_i3c_master_ops, false);
> -	if (ret)
> -		goto err_disable_sysclk;
> -
> -	return 0;
> -
> -err_disable_sysclk:
> -	clk_disable_unprepare(master->sysclk);
> -
> -err_disable_pclk:
> -	clk_disable_unprepare(master->pclk);
> -
> -	return ret;
> +	return i3c_master_register(&master->base, &pdev->dev,
> +				   &cdns_i3c_master_ops, false);
>  }
>
>  static void cdns_i3c_master_remove(struct platform_device *pdev)
> @@ -1668,9 +1644,6 @@ static void cdns_i3c_master_remove(struct platform_device *pdev)
>
>  	cancel_work_sync(&master->hj_work);
>  	i3c_master_unregister(&master->base);
> -
> -	clk_disable_unprepare(master->sysclk);
> -	clk_disable_unprepare(master->pclk);
>  }
>
>  static struct platform_driver cdns_i3c_master = {
> --
> 2.43.0
>