[v2] clk: rockchip: rk3588: Set SPLL frequency during SPL stage

From: Heiko Stuebner <heiko.stuebner@cherry.de>

All parts expect the SPLL to run at 702MHz. In U-Boot it's the SPLL_HZ
declaring this rate and in the kernel it's a fixed clock definition.

While everything is expecting 702MHz, the SPLL is not running that
frequency when coming from the bootrom though, instead it's running
at 351MHz and the vendor-u-boot just sets it to the expected frequency.

The SPLL itself is located inside the secure-BUSCRU and in theory
accessible as an SCMI clock, though this requires an unknown amount
of cooperation from trusted-firmware to set at a later stage, though
during the SPL stage we can still access the relevant CRU directly.

The SPLL is for example necessary for the DSI controllers to produce
output.

As the SPLL is "just" another rk3588 pll, just set the desired rate
directly during the SPL stage.

Tested on rk3588-rock5b and rk3588-tiger by reading back the PLL rate
and also observing working DSI output with this change.

Fixes: 6737771600d4 ("rockchip: rk3588: Add support for sdmmc clocks in SPL")
Suggested-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Quentin Schulz <quentin.schulz@cherry.de>
---
changes in v2:
- use correct name for SBUSCRU
- use dedicated constants for SBUSCRU registers
- add comment to make it explicit that the SPLL is in a different CRU

 .../include/asm/arch-rockchip/cru_rk3588.h    |  4 +++
 drivers/clk/rockchip/clk_rk3588.c             | 30 +++++++++++++++++--
 2 files changed, 31 insertions(+), 3 deletions(-)

On 2024/5/23 01:31, Heiko Stuebner wrote:
> From: Heiko Stuebner <heiko.stuebner@cherry.de>
>
> All parts expect the SPLL to run at 702MHz. In U-Boot it's the SPLL_HZ
> declaring this rate and in the kernel it's a fixed clock definition.
>
> While everything is expecting 702MHz, the SPLL is not running that
> frequency when coming from the bootrom though, instead it's running
> at 351MHz and the vendor-u-boot just sets it to the expected frequency.
>
> The SPLL itself is located inside the secure-BUSCRU and in theory
> accessible as an SCMI clock, though this requires an unknown amount
> of cooperation from trusted-firmware to set at a later stage, though
> during the SPL stage we can still access the relevant CRU directly.
>
> The SPLL is for example necessary for the DSI controllers to produce
> output.
>
> As the SPLL is "just" another rk3588 pll, just set the desired rate
> directly during the SPL stage.
>
> Tested on rk3588-rock5b and rk3588-tiger by reading back the PLL rate
> and also observing working DSI output with this change.
>
> Fixes: 6737771600d4 ("rockchip: rk3588: Add support for sdmmc clocks in SPL")
> Suggested-by: Andy Yan <andy.yan@rock-chips.com>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
> Cc: Jonas Karlman <jonas@kwiboo.se>
> Cc: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

Thanks,
- Kever
> ---
> changes in v2:
> - use correct name for SBUSCRU
> - use dedicated constants for SBUSCRU registers
> - add comment to make it explicit that the SPLL is in a different CRU
>
>   .../include/asm/arch-rockchip/cru_rk3588.h    |  4 +++
>   drivers/clk/rockchip/clk_rk3588.c             | 30 +++++++++++++++++--
>   2 files changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/include/asm/arch-rockchip/cru_rk3588.h b/arch/arm/include/asm/arch-rockchip/cru_rk3588.h
> index a4507e5fdd7..a0e54d39654 100644
> --- a/arch/arm/include/asm/arch-rockchip/cru_rk3588.h
> +++ b/arch/arm/include/asm/arch-rockchip/cru_rk3588.h
> @@ -29,6 +29,7 @@ enum rk3588_pll_id {
>   	V0PLL,
>   	AUPLL,
>   	PPLL,
> +	SPLL,
>   	PLL_COUNT,
>   };
>   
> @@ -150,6 +151,9 @@ struct pll_rate_table {
>   #define RK3588_DSU_CLKGATE_CON(x)	((x) * 0x4 + RK3588_DSU_CRU_BASE + 0x800)
>   #define RK3588_DSU_SOFTRST_CON(x)	((x) * 0x4 + RK3588_DSU_CRU_BASE + 0xa00)
>   
> +#define RK3588_SBUSCRU_SPLL_CON(x)	((x) * 0x4 + 0x220)
> +#define RK3588_SBUSCRU_MODE_CON0	0x280
> +
>   enum {
>   	/* CRU_CLK_SEL8_CON */
>   	ACLK_LOW_TOP_ROOT_SRC_SEL_SHIFT		= 14,
> diff --git a/drivers/clk/rockchip/clk_rk3588.c b/drivers/clk/rockchip/clk_rk3588.c
> index 4c611a39049..c41c9be6aa3 100644
> --- a/drivers/clk/rockchip/clk_rk3588.c
> +++ b/drivers/clk/rockchip/clk_rk3588.c
> @@ -37,6 +37,7 @@ static struct rockchip_pll_rate_table rk3588_pll_rates[] = {
>   	RK3588_PLL_RATE(786000000, 1, 131, 2, 0),
>   	RK3588_PLL_RATE(742500000, 4, 495, 2, 0),
>   	RK3588_PLL_RATE(722534400, 8, 963, 2, 24850),
> +	RK3588_PLL_RATE(702000000, 3, 351, 2, 0),
>   	RK3588_PLL_RATE(600000000, 2, 200, 2, 0),
>   	RK3588_PLL_RATE(594000000, 2, 198, 2, 0),
>   	RK3588_PLL_RATE(200000000, 3, 400, 4, 0),
> @@ -65,6 +66,15 @@ static struct rockchip_pll_clock rk3588_pll_clks[] = {
>   		     RK3588_MODE_CON0, 0, 15, 0, rk3588_pll_rates),
>   	[PPLL] = PLL(pll_rk3588, PLL_PPLL, RK3588_PMU_PLL_CON(128),
>   		     RK3588_MODE_CON0, 10, 15, 0, rk3588_pll_rates),
> +#ifdef CONFIG_SPL_BUILD
> +	/*
> +	 * The SPLL is part of the SBUSCRU, not the main CRU and as
> +	 * such only directly accessible during the SPL stage.
> +	 */
> +	[SPLL] = PLL(pll_rk3588, 0, RK3588_SBUSCRU_SPLL_CON(0),
> +		     RK3588_SBUSCRU_MODE_CON0, 0, 15, 0, rk3588_pll_rates),
> +#endif
> +
>   };
>   
>   #ifndef CONFIG_SPL_BUILD
> @@ -2044,6 +2054,7 @@ U_BOOT_DRIVER(rockchip_rk3588_cru) = {
>   
>   #ifdef CONFIG_SPL_BUILD
>   #define SCRU_BASE			0xfd7d0000
> +#define SBUSCRU_BASE			0xfd7d8000
>   
>   static ulong rk3588_scru_clk_get_rate(struct clk *clk)
>   {
> @@ -2118,15 +2129,28 @@ static ulong rk3588_scru_clk_set_rate(struct clk *clk, ulong rate)
>   	return rk3588_scru_clk_get_rate(clk);
>   }
>   
> +static int rk3588_scru_clk_probe(struct udevice *dev)
> +{
> +	int ret;
> +
> +	ret = rockchip_pll_set_rate(&rk3588_pll_clks[SPLL],
> +				    (void *)SBUSCRU_BASE, SPLL, SPLL_HZ);
> +	if (ret)
> +		debug("%s setting spll rate failed %d\n", __func__, ret);
> +
> +	return 0;
> +}
> +
>   static const struct clk_ops rk3588_scru_clk_ops = {
>   	.get_rate = rk3588_scru_clk_get_rate,
>   	.set_rate = rk3588_scru_clk_set_rate,
>   };
>   
>   U_BOOT_DRIVER(rockchip_rk3588_scru) = {
> -	.name = "rockchip_rk3588_scru",
> -	.id = UCLASS_CLK,
> -	.ops = &rk3588_scru_clk_ops,
> +	.name	= "rockchip_rk3588_scru",
> +	.id	= UCLASS_CLK,
> +	.ops	= &rk3588_scru_clk_ops,
> +	.probe	= rk3588_scru_clk_probe,
>   };
>   
>   static int rk3588_scmi_spl_glue_bind(struct udevice *dev)