[PATCH 2/2] usb: chipidea: usbmisc: Add support for i.MX51 CPU

[Matt Sealey]

I'd prefer this was kept separated out a little bit, as follows:

On Sun, Nov 10, 2013 at 1:18 AM, Alexander Shiyan <shc_work at mail.ru> wrote:
> This adds i.MX51 as the next user of the usbmisc driver.
> Since the functional is similar i.MX53, we just rename the
> definitions and add an alias for the new CPU.
>
> Signed-off-by: Alexander Shiyan <shc_work at mail.ru>
> ---
>  drivers/usb/chipidea/usbmisc_imx.c | 40 +++++++++++++++++++++-----------------
>  1 file changed, 22 insertions(+), 18 deletions(-)
>
>
> -static int usbmisc_imx53_init(struct imx_usbmisc_data *data)
> +static int usbmisc_imx5_init(struct imx_usbmisc_data *data)

Can we keep usbmisc_imx53_init named this?

There is more to do here on i.MX5 for cases where the bootloader did
not already try to set up USB (or did it badly) such as the
transceiver reference clock rate and also setting the USB sysclk clock
source (internal DPLL or from external transceiver in the external
ULPI case) and so on, which is related and needs doing on both, but is
different on i.MX51 than i.MX53. This is information sort of best
passed in the PHY node that goes along with this, but it's set within
the usbmisc block of the chips so the usbmisc driver will have a
responsibility to go see if it's an external PHY that is feeding it's
clock back into the USB block in this way.

I am not sure we (Peter etc.) discussed how best to do this, the code
to pull the correct information out always seems kind of misplaced no
matter where it goes, but the responsibility for tweaking those
registers is most certainly this driver.

Essentially the layout of usbmisc->base + 0x10 register (USB_CTRL_1)
is different when doing the above, and dependent on a board-specific
option for the input clock to the transceiver. We could reduce a
little churn, later, when usbmisc_imx could be given related usbphy
information and actually do the right thing. I have a patch kinda
sitting in the wings to do this.. and two *real* pieces of consumer
hardware that need it, and some other kicking, to make USB work in the
never-touched-before-Linux case.

> -static const struct usbmisc_ops imx53_usbmisc_ops = {
> -       .init = usbmisc_imx53_init,
> +static const struct usbmisc_ops imx5_usbmisc_ops = {
> +       .init = usbmisc_imx5_init,
>  };

And keep imx53_usbmisc_ops named this?

>  static const struct usbmisc_ops imx6q_usbmisc_ops = {
> @@ -204,8 +204,12 @@ static const struct of_device_id usbmisc_imx_dt_ids[] = {
>                 .data = &imx27_usbmisc_ops,
>         },
>         {
> +               .compatible = "fsl,imx51-usbmisc",
> +               .data = &imx5_usbmisc_ops,

And then just use &imx53_usbmisc_ops?

This gives us some breathing room later to actually do the right thing
without additionally performing renames all over the place to make
imx5 -> imx53 (again)/imx51 (new).

Thanks,
Matt Sealey <neko at bakuhatsu.net>