[PATCH V2 3/5] clk: renesas: Add R8A774A1 clock tables

[Adam Ford]

On Fri, Jun 19, 2020 at 2:08 PM Marek Vasut <marek.vasut at gmail.com> wrote:
>
> On 6/19/20 5:52 PM, Adam Ford wrote:
> > On Fri, Jun 19, 2020 at 9:18 AM Marek Vasut wrote:
> >>
> >> On 6/19/20 3:58 PM, Adam Ford wrote:
> >>> This sync's the clock tables with the official release from
> >>> Renesas' repo based on U-Boot 2018.09 and modified to build into
> >>> the latest version of U-Boot.
> >>
> >> Can you import the clock table from Linux too ?
> >
> > Sure thing. Doing so actually removed a note for missing clocks.  :-)
>
> Nice
>
> >> [...]
> >>
> >>> +static const struct mstp_stop_table r8a774a1_mstp_table[] = {
> >>> +     { 0x00200000, 0x0, 0x00200000, 0 },
> >>> +     { 0xFFFFFFFF, 0x0, 0xFFFFFFFF, 0 },
> >>> +     { 0x340E2FDC, 0x2040, 0x340E2FDC, 0 },
> >>> +     { 0xFFFFFFDF, 0x400, 0xFFFFFFDF, 0 },
> >>> +     { 0x80000184, 0x180, 0x80000184, 0 },
> >>> +     { 0xC3FFFFFF, 0x0, 0xC3FFFFFF, 0 },
> >>> +     { 0xFFFFFFFF, 0x0, 0xFFFFFFFF, 0 },
> >>> +     { 0xFFFFFFFF, 0x0, 0xFFFFFFFF, 0 },
> >>> +     { 0x01F1FFF7, 0x0, 0x01F1FFF7, 0 },
> >>> +     { 0xFFFFFFFE, 0x0, 0xFFFFFFFE, 0 },
> >>> +     { 0xFFFEFFE0, 0x0, 0xFFFEFFE0, 0 },
> >>> +     { 0x000000B7, 0x0, 0x000000B7, 0 },
> >>> +};
> >>
> >> Can you check whether all those bits are really defined in the MSTP
> >> registers of the SoC ?
> >
> > Can you give me a point on how to interpret this table?  I copied it
> > from the Renesas release, and it looks the same as the table for the
> > R8A7796, but I don't know what it's supposed to do.
>
> Look into renesas_clk_remove() in
> drivers/clk/renesas/renesas-cpg-mssr.c
>
> > I found the RZG2M ref manual 1.00, and lists MSTPSR1-10 and
> > RMSTPCR1-10.  Their initial values vary between revisions of the
> > silicon for the RZ/G2M, but there are 12 entries in the table, so I am
> > not even sure I'm looking at the right stuff in the ref manual.
>
> You're looking at the correct part of the manual. The goal is to turn
> off all the clock expect required ones before booting Linux. The code
> (see above) should make it clear what each line means and which register
> is written.

This appears to work with a quick test, but I haven't exercised everything yet.

static const struct mstp_stop_table r8a774a1_mstp_table[] = {
{ 0x00000000, 0, 0x00000000, 0 },
{ 0xc3e81000, 0, 0xc3e81000, 0 },
{ 0x000E0FDC, 0, 0x000E0FDC, 0 },
{ 0xD00C7C1F, 0, 0xD00C7C1F, 0 },
{ 0x80000004, 0, 0x80000004, 0 },
{ 0x00DF0006, 0, 0x00DF0006, 0 },
{ 0XC5EACCCE, 0, 0XC5EACCCE, 0 },
{ 0x29E1401C, 0, 0x29E1401C, 0 },
{ 0x00009FF1, 0, 0x00009FF1, 0 },
{ 0xFC4FDFE0, 0, 0xFC4FDFE0, 0 },
{ 0xFFFEFFE8, 0, 0xFFFEFFE8, 0 },
};

I read through registers 1-10, but there doesn't appear to be a
register 0, so I left it as all 0's.
The rest of these I only set the bits based on flags that were
available for the RZ/G2M regardless of their default clock status.

Does this look right to you?  If you think it looks good, I'll submit
another revision.

thanks

adam