Re: [PATCH 1/3] clk: imx: pll14xx: avoid modify dram pll

From: Shawn Guo <shawnguo@kernel.org>
To: Peng Fan <peng.fan@nxp.com>, Leonard Crestez <leonard.crestez@nxp.com>
Cc: "sboyd@kernel.org" <sboyd@kernel.org>,
	"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
	"festevam@gmail.com" <festevam@gmail.com>,
	Abel Vesa <abel.vesa@nxp.com>,
	"kernel@pengutronix.de" <kernel@pengutronix.de>,
	dl-linux-imx <linux-imx@nxp.com>,
	Aisheng Dong <aisheng.dong@nxp.com>,
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Anson Huang <anson.huang@nxp.com>, Jacky Bai <ping.bai@nxp.com>
Subject: Re: [PATCH 1/3] clk: imx: pll14xx: avoid modify dram pll
Date: Sun, 12 Jan 2020 10:32:49 +0800	[thread overview]
Message-ID: <20200112023248.GY4456@T480> (raw)
In-Reply-To: <1577696903-27870-2-git-send-email-peng.fan@nxp.com>

On Mon, Dec 30, 2019 at 09:13:00AM +0000, Peng Fan wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> The dram pll is only expected to be modified in firmware,
> so we should only support read clk frequency in Linux Kernel.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>

@Leonard, do you agree?

Shawn

> ---
>  drivers/clk/imx/clk-pll14xx.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-pll14xx.c b/drivers/clk/imx/clk-pll14xx.c
> index 5b0519a81a7a..9288b21d4d59 100644
> --- a/drivers/clk/imx/clk-pll14xx.c
> +++ b/drivers/clk/imx/clk-pll14xx.c
> @@ -69,8 +69,6 @@ struct imx_pll14xx_clk imx_1443x_pll = {
>  
>  struct imx_pll14xx_clk imx_1443x_dram_pll = {
>  	.type = PLL_1443X,
> -	.rate_table = imx_pll1443x_tbl,
> -	.rate_count = ARRAY_SIZE(imx_pll1443x_tbl),
>  	.flags = CLK_GET_RATE_NOCACHE,
>  };
>  
> @@ -376,6 +374,10 @@ static const struct clk_ops clk_pll1443x_ops = {
>  	.set_rate	= clk_pll1443x_set_rate,
>  };
>  
> +static const struct clk_ops clk_pll1443x_min_ops = {
> +	.recalc_rate	= clk_pll1443x_recalc_rate,
> +};
> +
>  struct clk_hw *imx_clk_hw_pll14xx(const char *name, const char *parent_name,
>  				  void __iomem *base,
>  				  const struct imx_pll14xx_clk *pll_clk)
> @@ -403,7 +405,10 @@ struct clk_hw *imx_clk_hw_pll14xx(const char *name, const char *parent_name,
>  			init.ops = &clk_pll1416x_ops;
>  		break;
>  	case PLL_1443X:
> -		init.ops = &clk_pll1443x_ops;
> +		if (!pll_clk->rate_table)
> +			init.ops = &clk_pll1443x_min_ops;
> +		else
> +			init.ops = &clk_pll1443x_ops;
>  		break;
>  	default:
>  		pr_err("%s: Unknown pll type for pll clk %s\n",
> -- 
> 2.16.4
> 