[PATCH v2 8/8] rockchip: Enable PCIe/M.2 on rock960 board

[Jagan Teki]

On Sun, May 3, 2020 at 7:09 PM Manivannan Sadhasivam
<manivannan.sadhasivam at linaro.org> wrote:
>
> On Thu, Apr 30, 2020 at 12:34:12PM +0530, Jagan Teki wrote:
> > Due to some on board limitation rock960 PCIe
> > works only with 1.8V IO domain.
> >
> > So, this patch enables grf io_sel explicitly
> > to make PCIe/M.2 to work.
> >
> > Cc: Tom Cubie <tom at radxa.com>
> > Cc: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > ---
> > Changes for v2:
> > - none
> >
> >  board/vamrs/rock960_rk3399/rock960-rk3399.c | 20 ++++++++++++++++++++
> >  configs/rock960-rk3399_defconfig            |  5 +++++
> >  2 files changed, 25 insertions(+)
> >
> > diff --git a/board/vamrs/rock960_rk3399/rock960-rk3399.c b/board/vamrs/rock960_rk3399/rock960-rk3399.c
> > index 68a127b9ac..98d62e89ca 100644
> > --- a/board/vamrs/rock960_rk3399/rock960-rk3399.c
> > +++ b/board/vamrs/rock960_rk3399/rock960-rk3399.c
> > @@ -2,3 +2,23 @@
> >  /*
> >   * Copyright (C) 2018 Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> >   */
> > +
> > +#include <common.h>
> > +#include <syscon.h>
> > +#include <asm/io.h>
> > +#include <asm/arch-rockchip/clock.h>
> > +#include <asm/arch-rockchip/grf_rk3399.h>
> > +#include <asm/arch-rockchip/hardware.h>
> > +
> > +#ifdef CONFIG_MISC_INIT_R
> > +int misc_init_r(void)
> > +{
> > +     struct rk3399_grf_regs *grf =
> > +         syscon_get_first_range(ROCKCHIP_SYSCON_GRF);
> > +
> > +     /* BT565 is in 1.8v domain */
>
> From where this BT565 comes in?

If my understanding was correct, some SSD's to work on this board do
require this explicit domain voltage change. Usually it requires GPIO
enablement followed by grf voltage domain update [1] but in my case it
worked w/o gpio.

Maybe I will update this details in the commit message and also in the code.

[1] https://github.com/radxa/u-boot/blob/stable-4.4-rockpi4/board/rockchip/evb_rk3399/evb-rk3399.c#L194

Jagan.