linux-kernel - Re: [PATCH v7 05/19] clk: mediatek: reset: Merge and revise reset register function

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Date:   Fri, 20 May 2022 11:12:12 -0400
From:   Nícolas F. R. A. Prado 
        <nfraprado@...labora.com>
To:     Rex-BC Chen <rex-bc.chen@...iatek.com>
Cc:     mturquette@...libre.com, sboyd@...nel.org, matthias.bgg@...il.com,
        robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
        p.zabel@...gutronix.de, angelogioacchino.delregno@...labora.com,
        chun-jie.chen@...iatek.com, wenst@...omium.org,
        runyang.chen@...iatek.com, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org,
        Project_Global_Chrome_Upstream_Group@...iatek.com
Subject: Re: [PATCH v7 05/19] clk: mediatek: reset: Merge and revise reset
 register function

Hi Rex,

On Thu, May 19, 2022 at 08:55:13PM +0800, Rex-BC Chen wrote:
> There are two versions for clock reset register control for MediaTek
> SoCs. The old hardware is one bit per reset control, and does not
> have separate registers for bit set, clear and read-back operations.
> This matches the scheme supported by the simple reset driver.
> 
> However, because we need to use different data structure from
> reset_simple_data, we can not use the operation of simple reset
> driver.
> For this reason, we keep the original functions and name this version
> as "MTK_RST_SIMPLE".
> 
> In this patch:
> - Add a version enumeration to separate different reset hardware.
> - Merge the reset register function of simple and set_clr into one
>   function "mtk_register_reset_controller".
> - Rename input variable "num_regs" to "rst_bank_nr" to avoid
>   confusion. This variable is used to define the quantity of reset bank.
> - Document mtk_reset_version and mtk_register_reset_controller.
> 
> Signed-off-by: Rex-BC Chen <rex-bc.chen@...iatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
> ---

<snip>

> index 764a8affe206..2a39eec9cff7 100644
> --- a/drivers/clk/mediatek/reset.h
> +++ b/drivers/clk/mediatek/reset.h
> @@ -9,16 +9,32 @@
>  #include <linux/reset-controller.h>
>  #include <linux/types.h>
>  
> +/**
> + * enum mtk_reset_version - Version of MediaTek clock reset controller.
> + * @MTK_RST_SIMPLE: Use the same registers for bit set and clear.
> + * @MTK_RST_SET_CLR: Use separate registers for bit set and clear.
> + * @MTK_RST_MAX: Total quantity of version for MediaTek clock reset controller.
> + */
> +enum mtk_reset_version {
> +	MTK_RST_SIMPLE = 0,
> +	MTK_RST_SET_CLR,
> +	MTK_RST_MAX,
> +};
> +
>  struct mtk_reset {
>  	struct regmap *regmap;
>  	int regofs;
>  	struct reset_controller_dev rcdev;
>  };
>  
> +/**
> + * mtk_register_reset_controller - Register MediaTek clock reset controller
> + * @np: Pointer to device node.
> + * @rst_bank_nr: Quantity of reset bank.
> + * @reg_ofs: Base offset of the reset register.
> + * @version: Version of MediaTek clock reset controller.
> + */
>  void mtk_register_reset_controller(struct device_node *np,
> -				   unsigned int num_regs, int regofs);
> -
> -void mtk_register_reset_controller_set_clr(struct device_node *np,
> -					   unsigned int num_regs, int regofs);
> +				   u32 rst_bank_nr, u16 reg_ofs, u8 version);

Why not use 'enum mtk_reset_version' instead of a generic u8? Same thing when
you move it to a struct in patch 6.

Thanks,
Nícolas