linux-kernel - Re: [PATCH 4/8] soc: mediatek: mtk-svs: delete superfluous platform data entries

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Date:   Thu, 6 Oct 2022 19:43:10 +0800
From:   Roger Lu <roger.lu@...iatek.com>
To:     <matthias.bgg@...nel.org>, <jia-wei.chang@...iatek.com>
CC:     <nfraprado@...labora.com>, <khilman@...libre.com>,
        <linux-kernel@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <angelogioacchino.delregno@...labora.com>,
        Matthias Brugger <matthias.bgg@...il.com>
Subject: Re: [PATCH 4/8] soc: mediatek: mtk-svs: delete superfluous platform
 data entries

Hi Matthias Sir,

On Wed, 2022-09-28 at 17:55 +0200, matthias.bgg@...nel.org wrote:
> From: Matthias Brugger <matthias.bgg@...il.com>
> 
> The platform name and efuse parsing function pointer are only used while
> probing the device. Use them from the svs_platform_data struct instead.
> 
> Signed-off-by: Matthias Brugger <matthias.bgg@...il.com>
> ---
> 
>  drivers/soc/mediatek/mtk-svs.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-svs.c b/drivers/soc/mediatek/mtk-svs.c
> index 8342627f8dea..482cc8d7e7cf 100644
> --- a/drivers/soc/mediatek/mtk-svs.c
> +++ b/drivers/soc/mediatek/mtk-svs.c
> @@ -311,14 +311,12 @@ static const u32 svs_regs_v2[] = {
>  
>  /**
>   * struct svs_platform - svs platform control
> - * @name: svs platform name
>   * @base: svs platform register base
>   * @dev: svs platform device
>   * @main_clk: main clock for svs bank
>   * @pbank: svs bank pointer needing to be protected by spin_lock section
>   * @banks: svs banks that svs platform supports
>   * @rst: svs platform reset control
> - * @efuse_parsing: svs platform efuse parsing function pointer
>   * @efuse_max: total number of svs efuse
>   * @tefuse_max: total number of thermal efuse
>   * @regs: svs platform registers map
> @@ -327,14 +325,12 @@ static const u32 svs_regs_v2[] = {
>   * @tefuse: thermal efuse data received from NVMEM framework
>   */
>  struct svs_platform {
> -	char *name;
>  	void __iomem *base;
>  	struct device *dev;
>  	struct clk *main_clk;
>  	struct svs_bank *pbank;
>  	struct svs_bank *banks;
>  	struct reset_control *rst;
> -	bool (*efuse_parsing)(struct svs_platform *svsp);
>  	size_t efuse_max;
>  	size_t tefuse_max;
>  	const u32 *regs;
> @@ -2009,7 +2005,7 @@ static bool svs_is_efuse_data_correct(struct
> svs_platform *svsp)
>  	svsp->efuse_max /= sizeof(u32);
>  	nvmem_cell_put(cell);
>  
> -	return svsp->efuse_parsing(svsp);
> +	return true;
>  }

Based on the current coding design, I think this function can be removed. We can
rename/refactor `svs_thermal_efuse_get_data()` to `svs_get_efuse_data()` as
below. Is this acceptable? Thanks.

int svs_get_efuse_data(struct svs_platform *svsp, const char *nvmem_cell_name)
{
        struct nvmem_cell *cell;

        /* Thermal efuse parsing */
        cell = nvmem_cell_get(svsp->dev, nvmem_cell_name);
        if (IS_ERR_OR_NULL(cell)) {
                dev_err(svsp->dev, "no \"%s\"? %ld\n", nvmem_cell_name,
PTR_ERR(cell));
                return PTR_ERR(cell);
        }

        svsp->tefuse = nvmem_cell_read(cell, &svsp->tefuse_max);
        if (IS_ERR(svsp->tefuse)) {
                dev_err(svsp->dev, "cannot read thermal efuse: %ld\n",
                        PTR_ERR(svsp->tefuse));
                nvmem_cell_put(cell);
                return PTR_ERR(svsp->tefuse);
        }

        svsp->tefuse_max /= sizeof(u32);
        nvmem_cell_put(cell);

        return 0;
}

>  
>  static struct device *svs_get_subsys_device(struct svs_platform *svsp,
> @@ -2338,9 +2334,7 @@ static int svs_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	svsp->dev = &pdev->dev;
> -	svsp->name = svsp_data->name;
>  	svsp->banks = svsp_data->banks;
> -	svsp->efuse_parsing = svsp_data->efuse_parsing;
>  	svsp->regs = svsp_data->regs;
>  	svsp->bank_max = svsp_data->bank_max;
>  
> @@ -2351,6 +2345,12 @@ static int svs_probe(struct platform_device *pdev)
>  	if (!svs_is_efuse_data_correct(svsp)) {
>  		dev_notice(svsp->dev, "efuse data isn't correct\n");
>  		ret = -EPERM;
> +		goto svs_probe_free_efuse;
> +	}
> +

Remove `svs_is_efuse_data_correct()` and add below get-efuse-data function.

	ret = svs_get_efuse_data(svsp, "svs-calibration-data");
	if (ret)
		goto svs_probe_free_efuse;

> +	if (!svsp_data->efuse_parsing(svsp)) {
> +		dev_notice(svsp->dev, "efuse data parsing failed\n");
> +		ret = -EPERM;
>  		goto svs_probe_free_resource;
>  	}
>  
> @@ -2367,7 +2367,7 @@ static int svs_probe(struct platform_device *pdev)
>  	}
>  
>  	ret = devm_request_threaded_irq(svsp->dev, svsp_irq, NULL, svs_isr,
> -					IRQF_ONESHOT, svsp->name, svsp);
> +					IRQF_ONESHOT, svsp_data->name, svsp);
>  	if (ret) {
>  		dev_err(svsp->dev, "register irq(%d) failed: %d\n",
>  			svsp_irq, ret);
> @@ -2416,11 +2416,13 @@ static int svs_probe(struct platform_device *pdev)
>  	clk_disable_unprepare(svsp->main_clk);
>  
>  svs_probe_free_resource:

For current coding design, I suggest we rename the goto-label to
`svs_probe_free_tefuse` to identify the resource we free.

> -	if (!IS_ERR_OR_NULL(svsp->efuse))
> -		kfree(svsp->efuse);
>  	if (!IS_ERR_OR_NULL(svsp->tefuse))
>  		kfree(svsp->tefuse);
>  
> +svs_probe_free_efuse:
> +	if (!IS_ERR_OR_NULL(svsp->efuse))
> +		kfree(svsp->efuse);
> +
>  	return ret;
>  }
>  

Sincerely,
Roger Lu.