linux-kernel - Re: [PATCH 3/3] clk: imx8mp: remove SYS PLL 1/2 clock gates

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Date:   Fri, 25 Feb 2022 16:35:13 +0200
From:   Abel Vesa <abel.vesa@....com>
To:     "Peng Fan (OSS)" <peng.fan@....nxp.com>
Cc:     sboyd@...nel.org, robh+dt@...nel.org, shawnguo@...nel.org,
        s.hauer@...gutronix.de, kernel@...gutronix.de, festevam@...il.com,
        linux-imx@....com, linux-clk@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Peng Fan <peng.fan@....com>
Subject: Re: [PATCH 3/3] clk: imx8mp: remove SYS PLL 1/2 clock gates

On 22-02-25 16:17:33, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@....com>
> 
> Remove the PLL 1/2 gates as it make AMP clock management harder without
> obvious benifit.
> 
> Signed-off-by: Peng Fan <peng.fan@....com>
> ---
>  drivers/clk/imx/clk-imx8mp.c | 48 ++++++++++++------------------------
>  1 file changed, 16 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-imx8mp.c b/drivers/clk/imx/clk-imx8mp.c
> index f23b92906d3b..18f5b7c3ca9d 100644
> --- a/drivers/clk/imx/clk-imx8mp.c
> +++ b/drivers/clk/imx/clk-imx8mp.c
> @@ -480,44 +480,28 @@ static int imx8mp_clocks_probe(struct platform_device *pdev)
>  	hws[IMX8MP_ARM_PLL_OUT] = imx_clk_hw_gate("arm_pll_out", "arm_pll_bypass", anatop_base + 0x84, 11);
>  	hws[IMX8MP_SYS_PLL3_OUT] = imx_clk_hw_gate("sys_pll3_out", "sys_pll3_bypass", anatop_base + 0x114, 11);
>  
> -	hws[IMX8MP_SYS_PLL1_40M_CG] = imx_clk_hw_gate("sys_pll1_40m_cg", "sys_pll1_bypass", anatop_base + 0x94, 27);

Hmm, isn't there a chance that u-boot might gate these? Then, in kernel
you won't have a way to ungate them, leaving the consumers hanging.

> -	hws[IMX8MP_SYS_PLL1_80M_CG] = imx_clk_hw_gate("sys_pll1_80m_cg", "sys_pll1_bypass", anatop_base + 0x94, 25);
> -	hws[IMX8MP_SYS_PLL1_100M_CG] = imx_clk_hw_gate("sys_pll1_100m_cg", "sys_pll1_bypass", anatop_base + 0x94, 23);
> -	hws[IMX8MP_SYS_PLL1_133M_CG] = imx_clk_hw_gate("sys_pll1_133m_cg", "sys_pll1_bypass", anatop_base + 0x94, 21);
> -	hws[IMX8MP_SYS_PLL1_160M_CG] = imx_clk_hw_gate("sys_pll1_160m_cg", "sys_pll1_bypass", anatop_base + 0x94, 19);
> -	hws[IMX8MP_SYS_PLL1_200M_CG] = imx_clk_hw_gate("sys_pll1_200m_cg", "sys_pll1_bypass", anatop_base + 0x94, 17);
> -	hws[IMX8MP_SYS_PLL1_266M_CG] = imx_clk_hw_gate("sys_pll1_266m_cg", "sys_pll1_bypass", anatop_base + 0x94, 15);
> -	hws[IMX8MP_SYS_PLL1_400M_CG] = imx_clk_hw_gate("sys_pll1_400m_cg", "sys_pll1_bypass", anatop_base + 0x94, 13);
>  	hws[IMX8MP_SYS_PLL1_OUT] = imx_clk_hw_gate("sys_pll1_out", "sys_pll1_bypass", anatop_base + 0x94, 11);
>  
> -	hws[IMX8MP_SYS_PLL1_40M] = imx_clk_hw_fixed_factor("sys_pll1_40m", "sys_pll1_40m_cg", 1, 20);
> -	hws[IMX8MP_SYS_PLL1_80M] = imx_clk_hw_fixed_factor("sys_pll1_80m", "sys_pll1_80m_cg", 1, 10);
> -	hws[IMX8MP_SYS_PLL1_100M] = imx_clk_hw_fixed_factor("sys_pll1_100m", "sys_pll1_100m_cg", 1, 8);
> -	hws[IMX8MP_SYS_PLL1_133M] = imx_clk_hw_fixed_factor("sys_pll1_133m", "sys_pll1_133m_cg", 1, 6);
> -	hws[IMX8MP_SYS_PLL1_160M] = imx_clk_hw_fixed_factor("sys_pll1_160m", "sys_pll1_160m_cg", 1, 5);
> -	hws[IMX8MP_SYS_PLL1_200M] = imx_clk_hw_fixed_factor("sys_pll1_200m", "sys_pll1_200m_cg", 1, 4);
> -	hws[IMX8MP_SYS_PLL1_266M] = imx_clk_hw_fixed_factor("sys_pll1_266m", "sys_pll1_266m_cg", 1, 3);
> -	hws[IMX8MP_SYS_PLL1_400M] = imx_clk_hw_fixed_factor("sys_pll1_400m", "sys_pll1_400m_cg", 1, 2);
> +	hws[IMX8MP_SYS_PLL1_40M] = imx_clk_hw_fixed_factor("sys_pll1_40m", "sys_pll1_out", 1, 20);
> +	hws[IMX8MP_SYS_PLL1_80M] = imx_clk_hw_fixed_factor("sys_pll1_80m", "sys_pll1_out", 1, 10);
> +	hws[IMX8MP_SYS_PLL1_100M] = imx_clk_hw_fixed_factor("sys_pll1_100m", "sys_pll1_out", 1, 8);
> +	hws[IMX8MP_SYS_PLL1_133M] = imx_clk_hw_fixed_factor("sys_pll1_133m", "sys_pll1_out", 1, 6);
> +	hws[IMX8MP_SYS_PLL1_160M] = imx_clk_hw_fixed_factor("sys_pll1_160m", "sys_pll1_out", 1, 5);
> +	hws[IMX8MP_SYS_PLL1_200M] = imx_clk_hw_fixed_factor("sys_pll1_200m", "sys_pll1_out", 1, 4);
> +	hws[IMX8MP_SYS_PLL1_266M] = imx_clk_hw_fixed_factor("sys_pll1_266m", "sys_pll1_out", 1, 3);
> +	hws[IMX8MP_SYS_PLL1_400M] = imx_clk_hw_fixed_factor("sys_pll1_400m", "sys_pll1_out", 1, 2);
>  	hws[IMX8MP_SYS_PLL1_800M] = imx_clk_hw_fixed_factor("sys_pll1_800m", "sys_pll1_out", 1, 1);
>  
> -	hws[IMX8MP_SYS_PLL2_50M_CG] = imx_clk_hw_gate("sys_pll2_50m_cg", "sys_pll2_bypass", anatop_base + 0x104, 27);
> -	hws[IMX8MP_SYS_PLL2_100M_CG] = imx_clk_hw_gate("sys_pll2_100m_cg", "sys_pll2_bypass", anatop_base + 0x104, 25);
> -	hws[IMX8MP_SYS_PLL2_125M_CG] = imx_clk_hw_gate("sys_pll2_125m_cg", "sys_pll2_bypass", anatop_base + 0x104, 23);
> -	hws[IMX8MP_SYS_PLL2_166M_CG] = imx_clk_hw_gate("sys_pll2_166m_cg", "sys_pll2_bypass", anatop_base + 0x104, 21);
> -	hws[IMX8MP_SYS_PLL2_200M_CG] = imx_clk_hw_gate("sys_pll2_200m_cg", "sys_pll2_bypass", anatop_base + 0x104, 19);
> -	hws[IMX8MP_SYS_PLL2_250M_CG] = imx_clk_hw_gate("sys_pll2_250m_cg", "sys_pll2_bypass", anatop_base + 0x104, 17);
> -	hws[IMX8MP_SYS_PLL2_333M_CG] = imx_clk_hw_gate("sys_pll2_333m_cg", "sys_pll2_bypass", anatop_base + 0x104, 15);
> -	hws[IMX8MP_SYS_PLL2_500M_CG] = imx_clk_hw_gate("sys_pll2_500m_cg", "sys_pll2_bypass", anatop_base + 0x104, 13);
>  	hws[IMX8MP_SYS_PLL2_OUT] = imx_clk_hw_gate("sys_pll2_out", "sys_pll2_bypass", anatop_base + 0x104, 11);
>  
> -	hws[IMX8MP_SYS_PLL2_50M] = imx_clk_hw_fixed_factor("sys_pll2_50m", "sys_pll2_50m_cg", 1, 20);
> -	hws[IMX8MP_SYS_PLL2_100M] = imx_clk_hw_fixed_factor("sys_pll2_100m", "sys_pll2_100m_cg", 1, 10);
> -	hws[IMX8MP_SYS_PLL2_125M] = imx_clk_hw_fixed_factor("sys_pll2_125m", "sys_pll2_125m_cg", 1, 8);
> -	hws[IMX8MP_SYS_PLL2_166M] = imx_clk_hw_fixed_factor("sys_pll2_166m", "sys_pll2_166m_cg", 1, 6);
> -	hws[IMX8MP_SYS_PLL2_200M] = imx_clk_hw_fixed_factor("sys_pll2_200m", "sys_pll2_200m_cg", 1, 5);
> -	hws[IMX8MP_SYS_PLL2_250M] = imx_clk_hw_fixed_factor("sys_pll2_250m", "sys_pll2_250m_cg", 1, 4);
> -	hws[IMX8MP_SYS_PLL2_333M] = imx_clk_hw_fixed_factor("sys_pll2_333m", "sys_pll2_333m_cg", 1, 3);
> -	hws[IMX8MP_SYS_PLL2_500M] = imx_clk_hw_fixed_factor("sys_pll2_500m", "sys_pll2_500m_cg", 1, 2);
> +	hws[IMX8MP_SYS_PLL2_50M] = imx_clk_hw_fixed_factor("sys_pll2_50m", "sys_pll2_out", 1, 20);
> +	hws[IMX8MP_SYS_PLL2_100M] = imx_clk_hw_fixed_factor("sys_pll2_100m", "sys_pll2_out", 1, 10);
> +	hws[IMX8MP_SYS_PLL2_125M] = imx_clk_hw_fixed_factor("sys_pll2_125m", "sys_pll2_out", 1, 8);
> +	hws[IMX8MP_SYS_PLL2_166M] = imx_clk_hw_fixed_factor("sys_pll2_166m", "sys_pll2_out", 1, 6);
> +	hws[IMX8MP_SYS_PLL2_200M] = imx_clk_hw_fixed_factor("sys_pll2_200m", "sys_pll2_out", 1, 5);
> +	hws[IMX8MP_SYS_PLL2_250M] = imx_clk_hw_fixed_factor("sys_pll2_250m", "sys_pll2_out", 1, 4);
> +	hws[IMX8MP_SYS_PLL2_333M] = imx_clk_hw_fixed_factor("sys_pll2_333m", "sys_pll2_out", 1, 3);
> +	hws[IMX8MP_SYS_PLL2_500M] = imx_clk_hw_fixed_factor("sys_pll2_500m", "sys_pll2_out", 1, 2);
>  	hws[IMX8MP_SYS_PLL2_1000M] = imx_clk_hw_fixed_factor("sys_pll2_1000m", "sys_pll2_out", 1, 1);
>  
>  	hws[IMX8MP_CLK_A53_DIV] = imx8m_clk_hw_composite_core("arm_a53_div", imx8mp_a53_sels, ccm_base + 0x8000);
> -- 
> 2.25.1
>