[PATCH 3/3] arm: dts: imx8mp: Sync with Linux 6.3

[Adam Ford]

On Wed, May 24, 2023 at 9:02 PM Fabio Estevam <festevam at gmail.com> wrote:
>
> Hi Tim,
>
> On Fri, May 19, 2023 at 8:00 PM Tim Harvey <tharvey at gateworks.com> wrote:
>
> > Fabio,

+ Marek
I am adding Marek since he did the HSIO power domain driver.

> >
> > There's more to be done here also. With this patch, and with the
> > spba-bus added to u-boot.dtsi, if you try to enable usb (usb start)
> > you get:
> > starting USB...
> > Bus usb at 38200000:
> > Enable clock-controller at 30380000 failed
> > probe failed, error -2
> > No working controllers found
>
> Does this help?

A bit.  I finally got some time to try to troubleshoot USB on my 8MP.

>
> --- a/drivers/clk/imx/clk-imx8mp.c
> +++ b/drivers/clk/imx/clk-imx8mp.c
> @@ -337,8 +337,8 @@ static int imx8mp_clk_probe(struct udevice *dev)
>         clk_dm(IMX8MP_CLK_UART2_ROOT, imx_clk_gate4("uart2_root_clk",
> "uart2", base + 0x44a0, 0));
>         clk_dm(IMX8MP_CLK_UART3_ROOT, imx_clk_gate4("uart3_root_clk",
> "uart3", base + 0x44b0, 0));
>         clk_dm(IMX8MP_CLK_UART4_ROOT, imx_clk_gate4("uart4_root_clk",
> "uart4", base + 0x44c0, 0));
> -       clk_dm(IMX8MP_CLK_USB_ROOT, imx_clk_gate4("usb_root_clk",
> "usb_core_ref", base + 0x44d0, 0));
> -       clk_dm(IMX8MP_CLK_USB_PHY_ROOT,

IMX8MP_CLK_USB_PHY_ROOT is also referenced in the device tree, so I
don't think we can delete it. I had  keep IMX8MP_CLK_USB_ROOT, and
IMX8MP_CLK_USB_PHY_ROOT while also adding IMX8MP_CLK_USB_SUSP.

> imx_clk_gate4("usb_phy_root_clk", "usb_phy_ref", base + 0x44f0, 0));
> +       clk_dm(IMX8MP_CLK_USB_ROOT, imx_clk_gate4("usb_root_clk",
> "hsio_axi", base + 0x44d0, 0));
> +       clk_dm(IMX8MP_CLK_USB_SUSP, imx_clk_gate4("usb_suspend_clk",
> "osc_32k", base + 0x44d0, 0));
>         clk_dm(IMX8MP_CLK_USDHC1_ROOT,
> imx_clk_gate4("usdhc1_root_clk", "usdhc1", base + 0x4510, 0));
>         clk_dm(IMX8MP_CLK_USDHC2_ROOT,
> imx_clk_gate4("usdhc2_root_clk", "usdhc2", base + 0x4520, 0));
>         clk_dm(IMX8MP_CLK_WDOG1_ROOT, imx_clk_gate4("wdog1_root_clk",
> "wdog", base + 0x4530, 0));

At this point, the missing clock errors go away, but it hangs.  I
updated my 8MP USB clocks based on the latest Linux kernel so my
clocks looks like:

clk_dm(IMX8MP_CLK_USB_ROOT, imx_clk_gate2("usb_root_clk", "hsio_axi",
base + 0x44d0, 0));
clk_dm(IMX8MP_CLK_USB_SUSP, imx_clk_gate2("usb_suspend_clk",
"clock-osc-24m", base + 0x44d0, 0));
clk_dm(IMX8MP_CLK_USB_PHY_ROOT, imx_clk_gate4("usb_phy_root_clk",
"usb_phy_ref", base + 0x44f0, 0));

The linux kernel uses gate2 for USB_ROOT and USB_SUSP while gate4 is
used for IMX8MP_CLK_USB_PHY_ROOT.  I didn't verify this against the
reference manual.

With some debugging enabled, it looks to me like it might be
power-domain related, but I am not 100% certain.
When I start the USB, it appears to go through some clocks, and start
one power domain, but I think we have a power-domain chain where one
power domain starts another.  I saw a patch on another thread for
enabling parent power-domains, but it didn't seem to help me.

u-boot=> usb start
starting USB...
Bus usb at 38200000: ofnode_read_prop: maximum-speed: <not found>
ofnode_read_prop: dr_mode: host
dev_power_domain_on usb at 32f10108
ofnode_read_prop: assigned-clock-rates: <not found>
Looking for clock-controller at 30380000
Looking for clock-controller at 30380000
   - result for clock-controller at 30380000: clock-controller at 30380000 (ret=0)
   - result for clock-controller at 30380000: clock-controller at 30380000 (ret=0)
Looking for clock-controller at 30380000
Looking for clock-controller at 30380000
   - result for clock-controller at 30380000: clock-controller at 30380000 (ret=0)
   - result for clock-controller at 30380000: clock-controller at 30380000 (ret=0)
ofnode_read_prop: dr_mode: host

<hang>

I added some debug code to the imx8mp_hsiomix_on in HSIOmix power
domain driver, and it doesn't appear to be getting called, yet
dev_power_domain_on usb at 32f10108 should be invoking it.

I am not positive it's a power domain issue, that's my first guess.


Tim - have you had any success?

adam