Re: [PATCH] clk: starfive: jh7100: Use provided clocks instead of hardcoded names

[Samuel Holland]

Hi Geert,

On 2024-03-14 6:05 AM, Geert Uytterhoeven wrote:
> The Starfive JH7100 clock driver does not use the DT "clocks" property
> to find its external input clocks, but instead relies on the names of
> the actual external clock providers.  This is fragile, and caused
> breakage when sanitizing clock names in DT.
> 
> Fix this by obtaining the external input clocks through the DT "clocks"
> property, and using their clk_hw objects or corresponding name.
> 
> Fixes: f03606470886 ("riscv: dts: starfive: replace underscores in node names")
> Fixes: 4210be668a09ee20 ("clk: starfive: Add JH7100 clock generator driver")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> After this is applied, the workaround in commit 7921e231f85a349d
> ("riscv: dts: starfive: jh7100: fix root clock names") can be reverted.
> ---
>  drivers/clk/starfive/clk-starfive-jh7100.c | 47 +++++++++++++++-------
>  drivers/clk/starfive/clk-starfive-jh71x0.h |  1 +
>  2 files changed, 33 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/clk/starfive/clk-starfive-jh7100.c b/drivers/clk/starfive/clk-starfive-jh7100.c
> index 0342db24c27e10df..08e6f03f2cfc36c1 100644
> --- a/drivers/clk/starfive/clk-starfive-jh7100.c
> +++ b/drivers/clk/starfive/clk-starfive-jh7100.c
> @@ -7,6 +7,7 @@
>   * Copyright (C) 2021 Emil Renner Berthing <kernel@xxxxxxxx>
>   */
>  
> +#include <linux/clk.h>
>  #include <linux/clk-provider.h>
>  #include <linux/device.h>
>  #include <linux/init.h>
> @@ -18,10 +19,18 @@
>  #include "clk-starfive-jh71x0.h"
>  
>  /* external clocks */
> -#define JH7100_CLK_OSC_SYS		(JH7100_CLK_END + 0)
> -#define JH7100_CLK_OSC_AUD		(JH7100_CLK_END + 1)
> -#define JH7100_CLK_GMAC_RMII_REF	(JH7100_CLK_END + 2)
> -#define JH7100_CLK_GMAC_GR_MII_RX	(JH7100_CLK_END + 3)
> +enum {
> +	EXT_CLK_OSC_SYS,
> +	EXT_CLK_OSC_AUD,
> +	EXT_CLK_GMAC_RMII_REF,
> +	EXT_CLK_GMAC_GR_MII_RX,
> +	EXT_NUM_CLKS
> +};
> +
> +#define JH7100_CLK_OSC_SYS		(JH7100_CLK_END + EXT_CLK_OSC_SYS)
> +#define JH7100_CLK_OSC_AUD		(JH7100_CLK_END + EXT_CLK_OSC_AUD)
> +#define JH7100_CLK_GMAC_RMII_REF	(JH7100_CLK_END + EXT_CLK_GMAC_RMII_REF)
> +#define JH7100_CLK_GMAC_GR_MII_RX	(JH7100_CLK_END + EXT_CLK_GMAC_GR_MII_RX)
>  
>  static const struct jh71x0_clk_data jh7100_clk_data[] __initconst = {
>  	JH71X0__MUX(JH7100_CLK_CPUNDBUS_ROOT, "cpundbus_root", 0, 4,
> @@ -284,8 +293,12 @@ static struct clk_hw *jh7100_clk_get(struct of_phandle_args *clkspec, void *data
>  
>  static int __init clk_starfive_jh7100_probe(struct platform_device *pdev)
>  {
> +	static const char *jh7100_ext_clk[EXT_NUM_CLKS] =
> +		{ "osc_sys", "osc_aud", "gmac_rmii_ref", "gmac_gr_mii_rxclk" };
>  	struct jh71x0_clk_priv *priv;
> +	const char *osc_sys;
>  	unsigned int idx;
> +	struct clk *clk;
>  	int ret;
>  
>  	priv = devm_kzalloc(&pdev->dev, struct_size(priv, reg, JH7100_CLK_PLL0_OUT), GFP_KERNEL);
> @@ -298,13 +311,23 @@ static int __init clk_starfive_jh7100_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->base))
>  		return PTR_ERR(priv->base);
>  
> +	for (idx = 0; idx < EXT_NUM_CLKS; idx++) {
> +		clk = devm_clk_get(&pdev->dev, jh7100_ext_clk[idx]);
> +		if (IS_ERR(clk))
> +			return PTR_ERR(clk);
> +
> +		priv->ext[idx] = __clk_get_hw(clk);
> +	}
> +
> +	osc_sys = clk_hw_get_name(priv->ext[EXT_CLK_OSC_SYS]);
> +
>  	priv->pll[0] = devm_clk_hw_register_fixed_factor(priv->dev, "pll0_out",
> -							 "osc_sys", 0, 40, 1);
> +							 osc_sys, 0, 40, 1);
>  	if (IS_ERR(priv->pll[0]))
>  		return PTR_ERR(priv->pll[0]);
>  
>  	priv->pll[1] = devm_clk_hw_register_fixed_factor(priv->dev, "pll1_out",
> -							 "osc_sys", 0, 64, 1);
> +							 osc_sys, 0, 64, 1);

These should use devm_clk_hw_register_fixed_factor_parent_hw(). (Or you could
define a devm_clk_hw_register_fixed_factor_fw_name() and drop the other changes.)

Regards,
Samuel

>  	if (IS_ERR(priv->pll[1]))
>  		return PTR_ERR(priv->pll[1]);
>  
> @@ -331,16 +354,10 @@ static int __init clk_starfive_jh7100_probe(struct platform_device *pdev)
>  
>  			if (pidx < JH7100_CLK_PLL0_OUT)
>  				parents[i].hw = &priv->reg[pidx].hw;
> -			else if (pidx < JH7100_CLK_END)
> +			else if (pidx < JH7100_CLK_OSC_SYS)
>  				parents[i].hw = priv->pll[pidx - JH7100_CLK_PLL0_OUT];
> -			else if (pidx == JH7100_CLK_OSC_SYS)
> -				parents[i].fw_name = "osc_sys";
> -			else if (pidx == JH7100_CLK_OSC_AUD)
> -				parents[i].fw_name = "osc_aud";
> -			else if (pidx == JH7100_CLK_GMAC_RMII_REF)
> -				parents[i].fw_name = "gmac_rmii_ref";
> -			else if (pidx == JH7100_CLK_GMAC_GR_MII_RX)
> -				parents[i].fw_name = "gmac_gr_mii_rxclk";
> +			else if (pidx <= JH7100_CLK_GMAC_GR_MII_RX)
> +				parents[i].hw = priv->ext[pidx - JH7100_CLK_OSC_SYS];
>  		}
>  
>  		clk->hw.init = &init;
> diff --git a/drivers/clk/starfive/clk-starfive-jh71x0.h b/drivers/clk/starfive/clk-starfive-jh71x0.h
> index 23e052fc15495c41..4f46939179cd7418 100644
> --- a/drivers/clk/starfive/clk-starfive-jh71x0.h
> +++ b/drivers/clk/starfive/clk-starfive-jh71x0.h
> @@ -115,6 +115,7 @@ struct jh71x0_clk_priv {
>  	struct device *dev;
>  	void __iomem *base;
>  	struct clk_hw *pll[3];
> +	struct clk_hw *ext[4];
>  	struct jh71x0_clk reg[];
>  };
>