Re: [PATCH] dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets

From: Martin Blumenstingl
Date: Tue Mar 05 2019 - 17:02:59 EST


On Mon, Mar 4, 2019 at 11:49 AM Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
>
> The G12A Documentation lacked these 2 reset lines, but they are present and
> used for each USB 2 PHYs.
>
> Add them to the dt-bindings for the upcoming USB support.
>
> Fixes: dbfc54534dfc ("dt-bindings: reset: meson: add g12a bindings")
> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

> ---
> include/dt-bindings/reset/amlogic,meson-g12a-reset.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/dt-bindings/reset/amlogic,meson-g12a-reset.h b/include/dt-bindings/reset/amlogic,meson-g12a-reset.h
> index 8063e8314eef..6d487c5eba2c 100644
> --- a/include/dt-bindings/reset/amlogic,meson-g12a-reset.h
> +++ b/include/dt-bindings/reset/amlogic,meson-g12a-reset.h
> @@ -51,7 +51,10 @@
> #define RESET_SD_EMMC_A 44
> #define RESET_SD_EMMC_B 45
> #define RESET_SD_EMMC_C 46
> -/* 47-60 */
> +/* 47 */
> +#define RESET_USB_PHY20 48
> +#define RESET_USB_PHY21 49
because it's always hard to look up, here's the reference to that
information Amlogic's buildroot kernel
(buildroot_openlinux_kernel_4.9_fbdev_20180706):
kernel/aml-4.9/drivers/amlogic/usb/phy/phy-aml-new-usb2-v2.c uses:
writel((val | (0x3 << 16)), (void __iomem *) ((unsigned
long)phy->reset_regs + (0x21 * 4 - 0x8)));

this translates to:
- (0x21 * 4 - 0x8) = RESET1 register / reset line ID 32 and above
(reset line 0 is at "0x20 * 4 - 0x08")
- bits 16 and 17 = add 32 to that gives us reset IDs 48 and 49


Regards
Martin