[PATCH 2/2] [RFC] clk: stm32mp1: Handle SoC speed grade configs

[Patrick DELAUNAY]

Dear Marek,

> From: Marek Vasut <marex at denx.de>
> Sent: mardi 12 mai 2020 19:07
> 
> There are two speed grades of the STM32MP1, the A/C and D/F, the former can
> run up to 650 MHz, the later at up to 800 MHz. Allow specifying PLL config for
> both in the DT, so that it is possible to cater for boards which can be populated
> with either SoC.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Patrick Delaunay <patrick.delaunay at st.com>
> Cc: Patrice Chotard <patrice.chotard at st.com>
> ---
>  drivers/clk/clk_stm32mp1.c | 30 ++++++++++++++++++++++++++----
>  1 file changed, 26 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c index
> 50df8425bf..cecc06638e 100644
> --- a/drivers/clk/clk_stm32mp1.c
> +++ b/drivers/clk/clk_stm32mp1.c
> @@ -4,6 +4,7 @@
>   */
> 
>  #include <common.h>
> +#include <asm/arch/sys_proto.h>
>  #include <clk-uclass.h>
>  #include <div64.h>
>  #include <dm.h>
> @@ -1464,6 +1465,12 @@ static void pll_csg(struct stm32mp1_clk_priv *priv, int
> pll_id, u32 *csg)
>  	setbits_le32(priv->base + pll[pll_id].pllxcr, RCC_PLLNCR_SSCG_CTRL);
> }
> 
> +static __maybe_unused int stm32mp1_is_df(void) {
> +	/* ID bit 7 is set on 15x{D,F}xx and not on 15x{A,C}xx */
> +	return get_cpu_type() & BIT(7);
> +}
> +
>  static  __maybe_unused int pll_set_rate(struct udevice *dev,
>  					int pll_id,
>  					int div_id,
> @@ -1491,8 +1498,13 @@ static  __maybe_unused int pll_set_rate(struct
> udevice *dev,
> 
>  	ret = ofnode_read_u32_array(plloff, "cfg",
>  				    pllcfg, PLLCFG_NB);
> -	if (ret < 0)
> -		return -FDT_ERR_NOTFOUND;
> +	if (ret < 0) {
> +		ret = ofnode_read_u32_array(plloff,
> +				stm32mp1_is_df() ? "cfg-df" : "cfg-ac",
> +				pllcfg, PLLCFG_NB);
> +		if (ret < 0)
> +			return -FDT_ERR_NOTFOUND;
> +	}
> 
>  	fck_ref = pll_get_fref_ck(priv, pll_id);
> 
> @@ -1687,8 +1699,13 @@ static int stm32mp1_clktree(struct udevice *dev)
>  		ret = ofnode_read_u32_array(plloff[i], "cfg",
>  					    pllcfg[i], PLLCFG_NB);
>  		if (ret < 0) {
> -			debug("field cfg invalid: error %d\n", ret);
> -			return -FDT_ERR_NOTFOUND;
> +			ret = ofnode_read_u32_array(plloff[i],
> +					stm32mp1_is_df() ? "cfg-df" : "cfg-ac",
> +					pllcfg[i], PLLCFG_NB);
> +			if (ret < 0) {
> +				debug("field cfg invalid: error %d\n", ret);
> +				return -FDT_ERR_NOTFOUND;
> +			}
>  		}
>  	}
> 
> @@ -1783,6 +1800,11 @@ static int stm32mp1_clktree(struct udevice *dev)
>  			continue;
> 
>  		fracv = ofnode_read_u32_default(plloff[i], "frac", 0);
> +		if (!fracv) {
> +			fracv = ofnode_read_u32_default(plloff[i],
> +					stm32mp1_is_df() ? "frac-df" : "frac-ac",
> +					0);
> +		}
>  		pll_config(priv, i, pllcfg[i], fracv);
>  		ret = ofnode_read_u32_array(plloff[i], "csg", csg, PLLCSG_NB);
>  		if (!ret) {
> --
> 2.25.1

The 2 speed grade will be supported with OPP information and HW support,present in kernel device tree (upstream in progress) 

I port this patch in U-Boot with:
http://patchwork.ozlabs.org/project/uboot/patch/20200421171123.2.Id3620aec4deb419f1c1a5876b865556e86d3aba1@changeid/


Please check the full serie
stm32mp1: use OPP information for PLL1 settings in SPL
http://patchwork.ozlabs.org/project/uboot/list/?series=171767

PLL1 settings are now computed in SPL and no more read from DT.

Regards

Patrick