[PATCH V2 4/4] board: rockchip: Enable PD_VO before driver access

[Quentin Schulz]

Hi Chris,

On 9/23/24 7:38 PM, Chris Morgan wrote:
> On Mon, Sep 23, 2024 at 01:24:34PM +0200, Quentin Schulz wrote:
>> Hi Chris,
>>
>> On 9/19/24 4:00 PM, Chris Morgan wrote:
>>> From: Chris Morgan <macromorgan at hotmail.com>
>>>
>>> Enable the PD_VO power domain before driver access on the rk3568 SoC.
>>>
>>> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
>>> ---
>>>    arch/arm/mach-rockchip/rk3568/rk3568.c | 6 ++++++
>>>    1 file changed, 6 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-rockchip/rk3568/rk3568.c b/arch/arm/mach-rockchip/rk3568/rk3568.c
>>> index 1b3e40074e3..d5742b68d68 100644
>>> --- a/arch/arm/mach-rockchip/rk3568/rk3568.c
>>> +++ b/arch/arm/mach-rockchip/rk3568/rk3568.c
>>> @@ -26,6 +26,8 @@
>>>    #define PMU_BASE_ADDR		0xfdd90000
>>>    #define PMU_NOC_AUTO_CON0	(0x70)
>>>    #define PMU_NOC_AUTO_CON1	(0x74)
>>> +#define PMU_PWR_GATE_SFTCON	(0xa0)
>>> +#define PMU_PD_VO_DWN_ENA	BIT(7)
>>>    #define EDP_PHY_GRF_BASE	0xfdcb0000
>>>    #define EDP_PHY_GRF_CON0	(EDP_PHY_GRF_BASE + 0x00)
>>>    #define EDP_PHY_GRF_CON10	(EDP_PHY_GRF_BASE + 0x28)
>>> @@ -130,6 +132,10 @@ int arch_cpu_init(void)
>>>    	writel(0x3f3f0707, GRF_BASE + GRF_GPIO1C_DS_1);
>>>    	writel(0x3f3f0707, GRF_BASE + GRF_GPIO1C_DS_2);
>>>    	writel(0x3f3f0707, GRF_BASE + GRF_GPIO1C_DS_3);
>>> +
>>> +	/* Enable VO power domain for display */
>>> +	writel((PMU_PD_VO_DWN_ENA << 16),
>>> +	       PMU_BASE_ADDR + PMU_PWR_GATE_SFTCON);
>>
>> Maybe we want to guard this with a symbol for video stuff in U-Boot? I
>> assume Linux is capable of handling this just fine without U-Boot's
>> intervention?
>>
>> At the very least have #if CONFIG_IS_ENABLED(VIDEO) ?
>>
>> What do you think?
> 
> I'm game if you are. To me this just brings back the default behavior
> of the binary A-TF from Rockchip where the PD_VO was enabled, but if
> we want to guard this I'm okay.
> 

Just to be sure I understand correctly...

Would a device without this power domain enabled by U-Boot still have 
working video in Linux with upstream TF-A?

Cheers,
Quentin