[PATCH 2/6] clk: rockchip: fix wrong clk_ref_usb3otg parent for rk3328

[Jonas Karlman]

On 2024-12-10 14:27, Peter Geis wrote:
> On Tue, Dec 10, 2024 at 4:44 AM Dragan Simic <dsimic at manjaro.org> wrote:
>>
>> Hello Peter,
>>
>> On 2024-12-10 02:30, Peter Geis wrote:
>>> Correct the clk_ref_usb3otg parent to fix clock control for the usb3
>>> controller on rk3328. Verified against the rk3328 trm and usb3 clock
>>> tree
>>> documentation.
>>>
>>> Fixes: fe3511ad8a1c ("clk: rockchip: add clock controller for rk3328")
>>> Signed-off-by: Peter Geis <pgwipeout at gmail.com>
>>> ---
>>>
>>>  drivers/clk/rockchip/clk-rk3328.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clk/rockchip/clk-rk3328.c
>>> b/drivers/clk/rockchip/clk-rk3328.c
>>> index 3bb87b27b662..cf60fcf2fa5c 100644
>>> --- a/drivers/clk/rockchip/clk-rk3328.c
>>> +++ b/drivers/clk/rockchip/clk-rk3328.c
>>> @@ -201,7 +201,7 @@ PNAME(mux_aclk_peri_pre_p)        = { "cpll_peri",
>>>                                   "gpll_peri",
>>>                                   "hdmiphy_peri" };
>>>  PNAME(mux_ref_usb3otg_src_p) = { "xin24m",
>>> -                                 "clk_usb3otg_ref" };
>>> +                                 "clk_ref_usb3otg_src" };
>>>  PNAME(mux_xin24m_32k_p)              = { "xin24m",
>>>                                   "clk_rtc32k" };
>>>  PNAME(mux_mac2io_src_p)              = { "clk_mac2io_src",
>>
>> Sorry, but I was unable to verify this in the part 1 of the
>> RK3328 TRM, in both versions 1.1 and 1.2, which is all I have
>> when it comes to the RK3328 TRM.  Is that maybe described in
>> the part 2, which I've been unable to locate for years?
>>
>> Moreover, the downstream kernel source from Rockchip does it
>> the way [1] it's currently done in the mainline kernel, which
>> makes me confused a bit?  Could you, please, provide more
>> details about the two references you mentioned in the patch
>> description, or maybe even you could provide the links to
>> those two references?
>>
>> [1]
>> https://raw.githubusercontent.com/rockchip-linux/kernel/refs/heads/develop-4.4/drivers/clk/rockchip/clk-rk3328.c
> 
> It is unfortunate the TRM doesn't include the clock maps, because they
> are extremely helpful when one can acquire them. It also doesn't help
> that the TRM register definition only referred to this as "pll". I was
> sent specifically the usb3 phy clock map for my work on the driver,
> which had the location of each switch and divider along with the
> register and bit that controlled it. That combined with the TRM
> register map allowed me to find this error.

I can also confirm that the changes in this patch matches Fig. 3-8
RK3228H Clock Architecture Diagram 7 for the USB3OTG block.

                                    XIN24M -\
                                             S45_8 - ref_clk_usb3otg
S45_7 (2PLL) / G4_9 / S45_0 (DivFree 1~64) -/

Regards,
Jonas

> 
> Thanks!
> Peter
>