[PATCH] sunxi: spl: Fix H616 clock initialization

From: Andre Przywara <andre.przywara@arm.com>
To: u-boot@lists.denx.de
Subject: [PATCH] sunxi: spl: Fix H616 clock initialization
Date: Mon, 1 Feb 2021 00:46:22 +0000	[thread overview]
Message-ID: <20210201002735.21d2230a@slackpad.fritz.box> (raw)
In-Reply-To: <20210131202539.3735672-1-jernej.skrabec@siol.net>

On Sun, 31 Jan 2021 21:25:39 +0100
Jernej Skrabec <jernej.skrabec@siol.net> wrote:

Hi Jernej,

> It turns out that there is a magic bit in PRCM region which seemingly
> makes PLLs work if it's enabled. Sadly, there is no documentation what
> it does exactly, so we'll just mimick BSP boot0 behaviour and enable it
> before any clock is set up.

Good job of figuring this out!

> Fixes: b18bd53d6cde ("sunxi: introduce support for H616 clocks")
> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> ---
>  arch/arm/mach-sunxi/clock_sun50i_h6.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/arm/mach-sunxi/clock_sun50i_h6.c b/arch/arm/mach-sunxi/clock_sun50i_h6.c
> index 06d84eb158d7..68c8e7f2afbe 100644
> --- a/arch/arm/mach-sunxi/clock_sun50i_h6.c
> +++ b/arch/arm/mach-sunxi/clock_sun50i_h6.c
> @@ -9,6 +9,12 @@ void clock_init_safe(void)
>  {
>  	struct sunxi_ccm_reg *const ccm =
>  		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
> +
> +#ifdef CONFIG_MACH_SUN50I_H616

Can you change this to: if (IS_ENABLED())?

> +	/* this seems to enable PLLs */

Out of curiosity, what makes you think it's PLL related? At least the
PERIPH0 and CPU PLLs seem to work without it?

Cheers,
Andre

> +	setbits_le32(SUNXI_PRCM_BASE + 0x250, 0x10);
> +#endif
> +
>  	clock_set_pll1(408000000);
>  
>  	writel(CCM_PLL6_DEFAULT, &ccm->pll6_cfg);