[PATCH 0/2] ARM: shmobile: Add support for RZ/A2

[PATCH 0/2] ARM: shmobile: Add support for RZ/A2

[Chris Brandt]

Introduce RZ/A2 (R7S9210) as an SoC that can be selected.


Chris Brandt (2):
  ARM: shmobile: Add basic RZ/A2 SoC support
  dt-bindings: arm: Document RZ/A2 SoC DT bindings

 Documentation/devicetree/bindings/arm/shmobile.txt |  2 ++
 arch/arm/mach-shmobile/Kconfig                     |  6 +++++
 arch/arm/mach-shmobile/Makefile                    |  1 +
 arch/arm/mach-shmobile/setup-r7s9210.c             | 27 ++++++++++++++++++++++
 4 files changed, 36 insertions(+)
 create mode 100644 arch/arm/mach-shmobile/setup-r7s9210.c

-- 
2.16.1

[PATCH 1/2] ARM: shmobile: Add basic RZ/A2 SoC support

[Chris Brandt]

Add the RZ/A2 SoC to the Renesas SoC collection.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
---
 arch/arm/mach-shmobile/Kconfig         |  6 ++++++
 arch/arm/mach-shmobile/Makefile        |  1 +
 arch/arm/mach-shmobile/setup-r7s9210.c | 27 +++++++++++++++++++++++++++
 3 files changed, 34 insertions(+)
 create mode 100644 arch/arm/mach-shmobile/setup-r7s9210.c

diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index 0b67254eabb2..9338eb0d574f 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -54,6 +54,12 @@ config ARCH_R7S72100
 	select SYS_SUPPORTS_SH_MTU2
 	select RENESAS_OSTM
 
+config ARCH_R7S9210
+	bool "RZ/A2 (R7S9210)"
+	select PM
+	select PM_GENERIC_DOMAINS
+	select RENESAS_OSTM
+
 config ARCH_R8A73A4
 	bool "R-Mobile APE6 (R8A73A40)"
 	select ARCH_RMOBILE
diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile
index b33dc59d8698..5591646cb9bb 100644
--- a/arch/arm/mach-shmobile/Makefile
+++ b/arch/arm/mach-shmobile/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_ARCH_R8A7778)	+= setup-r8a7778.o
 obj-$(CONFIG_ARCH_R8A7779)	+= setup-r8a7779.o
 obj-$(CONFIG_ARCH_EMEV2)	+= setup-emev2.o
 obj-$(CONFIG_ARCH_R7S72100)	+= setup-r7s72100.o
+obj-$(CONFIG_ARCH_R7S9210)	+= setup-r7s9210.o
 
 # CPU reset vector handling objects
 cpu-y				:= platsmp.o headsmp.o
diff --git a/arch/arm/mach-shmobile/setup-r7s9210.c b/arch/arm/mach-shmobile/setup-r7s9210.c
new file mode 100644
index 000000000000..573fb9955e7e
--- /dev/null
+++ b/arch/arm/mach-shmobile/setup-r7s9210.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * r7s9210 processor support
+ *
+ * Copyright (C) 2018  Renesas Electronics Corporation
+ * Copyright (C) 2018  Chris Brandt
+ *
+ */
+
+#include <linux/kernel.h>
+
+#include <asm/mach/arch.h>
+
+#include "common.h"
+
+static const char *const r7s9210_boards_compat_dt[] __initconst = {
+	"renesas,r7s9210",
+	NULL,
+};
+
+DT_MACHINE_START(R7S72100_DT, "Generic R7S9210 (Flattened Device Tree)")
+	.l2c_aux_val    = 0,
+	.l2c_aux_mask   = ~0,
+	.init_early	= shmobile_init_delay,
+	.init_late	= shmobile_init_late,
+	.dt_compat	= r7s9210_boards_compat_dt,
+MACHINE_END
-- 
2.16.1

Re: [PATCH 1/2] ARM: shmobile: Add basic RZ/A2 SoC support

[Geert Uytterhoeven]

Hi Chris,

On Thu, Jul 12, 2018 at 5:02 AM Chris Brandt <chris.brandt@renesas.com> wrote:
> Add the RZ/A2 SoC to the Renesas SoC collection.
>
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>

> --- /dev/null
> +++ b/arch/arm/mach-shmobile/setup-r7s9210.c
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * r7s9210 processor support
> + *
> + * Copyright (C) 2018  Renesas Electronics Corporation
> + * Copyright (C) 2018  Chris Brandt
> + *
> + */
> +
> +#include <linux/kernel.h>
> +
> +#include <asm/mach/arch.h>
> +
> +#include "common.h"
> +
> +static const char *const r7s9210_boards_compat_dt[] __initconst = {
> +       "renesas,r7s9210",
> +       NULL,
> +};
> +
> +DT_MACHINE_START(R7S72100_DT, "Generic R7S9210 (Flattened Device Tree)")
> +       .l2c_aux_val    = 0,
> +       .l2c_aux_mask   = ~0,
> +       .init_early     = shmobile_init_delay,
> +       .init_late      = shmobile_init_late,
> +       .dt_compat      = r7s9210_boards_compat_dt,
> +MACHINE_END

I'm wondering if you could do without any board code, i.e. without
setup-r7s9210.c?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] ARM: shmobile: Add basic RZ/A2 SoC support

[Geert Uytterhoeven]

Hi Chris,

On Thu, Jul 12, 2018 at 5:40 PM Chris Brandt <Chris.Brandt@renesas.com> wrote:
> On Thursday, July 12, 2018, Geert Uytterhoeven wrote:
> > I'm wondering if you could do without any board code, i.e. without
> > setup-r7s9210.c?
>
> I think I see them being removed for R-Car.
> But....I'm not sure how that actually works.
>
> I'll have a look.
>
> As you can see, there's really nothing in the RZ/A1 setup file either.

Yeah, that's why I asked: setup-r7s72100.c is the smallest setup file.

It uses shmobile_init_delay() to preset loops-per-jiffy, to avoid
calibrating the
delay loop, and shmobile_init_late() to make s2ram do more than s2idle.
As RZ/A doesn't have SMP, and thus there's no use for disabling secondary
CPU cores, the impact of the latter is small (read: I don't know what's the real
impact of calling cpu_idle_poll_ctrl()).

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 1/2] ARM: shmobile: Add basic RZ/A2 SoC support

[Geert Uytterhoeven]

Hi Chris,

On Thu, Jul 12, 2018 at 7:34 PM Chris Brandt <Chris.Brandt@renesas.com> wrote:
> On Thursday, July 12, 2018, Geert Uytterhoeven wrote:
> > Yeah, that's why I asked: setup-r7s72100.c is the smallest setup file.
> >
> > It uses shmobile_init_delay() to preset loops-per-jiffy, to avoid
> > calibrating the
> > delay loop, and shmobile_init_late() to make s2ram do more than s2idle.
> > As RZ/A doesn't have SMP, and thus there's no use for disabling secondary
> > CPU cores, the impact of the latter is small (read: I don't know what's
> > the real
> > impact of calling cpu_idle_poll_ctrl()).
>
> It's been quite a while, but I remember when porting RZ/A1 code that
> without those two functions, things didn't work right. Of course that was
> many releases ago.

Right, you may not have had an early timer running yet, causing the loop
calibration to hang. May have been fixed by ostm support.

> However, one thing that I know I need is
>
> +       .l2c_aux_val    = 0,
> +       .l2c_aux_mask   = ~0,
>
> Without that, I don't get my L2C driver loaded.
>
> Hence:
> a96bb197693e ("ARM: 8660/1: shmobile: r7s72100: Enable L2 cache")
>
> So at least for now, I would say I still need the setup file.

I forgot about the L2C. Yeah, it's a pity we still need board code to
enable the PL310 cache with default settings.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH 2/2] dt-bindings: arm: Document RZ/A2 SoC DT bindings

[Chris Brandt]

Add device tree bindings documentation for Renesas RZ/A2 (r7s9210) SoC.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
---
 Documentation/devicetree/bindings/arm/shmobile.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/shmobile.txt b/Documentation/devicetree/bindings/arm/shmobile.txt
index 89b4a389fbc7..7288c2081cd5 100644
--- a/Documentation/devicetree/bindings/arm/shmobile.txt
+++ b/Documentation/devicetree/bindings/arm/shmobile.txt
@@ -7,6 +7,8 @@ SoCs:
     compatible = "renesas,emev2"
   - RZ/A1H (R7S72100)
     compatible = "renesas,r7s72100"
+  - RZ/A2 (R7S9210)
+    compatible = "renesas,r7s9210"
   - SH-Mobile AG5 (R8A73A00/SH73A0)
     compatible = "renesas,sh73a0"
   - R-Mobile APE6 (R8A73A40)
-- 
2.16.1

Re: [PATCH 2/2] dt-bindings: arm: Document RZ/A2 SoC DT bindings

[Geert Uytterhoeven]

Hi Chris,

On Thu, Jul 12, 2018 at 5:02 AM Chris Brandt <chris.brandt@renesas.com> wrote:
> Add device tree bindings documentation for Renesas RZ/A2 (r7s9210) SoC.
>
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

> --- a/Documentation/devicetree/bindings/arm/shmobile.txt
> +++ b/Documentation/devicetree/bindings/arm/shmobile.txt
> @@ -7,6 +7,8 @@ SoCs:
>      compatible = "renesas,emev2"
>    - RZ/A1H (R7S72100)
>      compatible = "renesas,r7s72100"
> +  - RZ/A2 (R7S9210)
> +    compatible = "renesas,r7s9210"

There seems to be a difference between the r7s92104x and the r7s92105x
parts (with "x" just denoting a different packaging)?
Do we need one more digit?

>    - SH-Mobile AG5 (R8A73A00/SH73A0)
>      compatible = "renesas,sh73a0"
>    - R-Mobile APE6 (R8A73A40)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 2/2] dt-bindings: arm: Document RZ/A2 SoC DT bindings

[Geert Uytterhoeven]

Hi Chris,

On Thu, Jul 12, 2018 at 3:15 PM Chris Brandt <Chris.Brandt@renesas.com> wrote:
> On Thursday, July 12, 2018, Geert Uytterhoeven wrote:
> > > +  - RZ/A2 (R7S9210)
> > > +    compatible = "renesas,r7s9210"
> >
> > There seems to be a difference between the r7s92104x and the r7s92105x
> > parts (with "x" just denoting a different packaging)?
> > Do we need one more digit?
>
> From an "architecture" standpoint all the hardware in the RZ/A2
> (R7S9210xx series) will be the same. So from a device driver standpoint,
> CONFIG_ARCH_R7S9210 would cover everything.
>
> The rest of the numbers are just for package and number of HW channels.
>
> Of course, sometimes when they make smaller packages, they also make
> smaller silicon to make it cheaper. But in that case, they just simply
> remove HW or the number of channels for the hardware. (you don't need as
> many peripherals if you don't have as many pins anymore). But, they never
> change the functionality of the hardware.
>
> Take for example RZ/A1
>  RZ/A1H  R7S72100x
>  RZ/A1M  R7S72101x
>  RZ/A1L  R7S72102x
>  RZ/A1LU R7S72103x
>
> These parts all had the same hardware, but different package options And
> the "L" parts were cheaper because they reduced the die size by
> removing HW.
> But the same drivers worked on all of them because the IP was all
> exactly the same.
> So I would have suggested CONFIG_ARCH_R7S7210 for the RZ/A1 series.
> (well, until I found about the R-Car part that took the same part number in
> this series)

That's the issue with using wildcards, or truncating part numbers: you
don't know what unrelated future parts may match...

> As for the r7s92104x vs r7s92105x, that is for a HW feature that will
> have nothing to do with Linux, so we can ignore that number.

OK.

> But even if we did make a tiny cut-down version of the device, say a
> R7S92106x, all HW IP would be the same, just less of it. So in my mind, the
> architecture (from a CONFIG_ARCH perspective) is still the same. Maybe
> just a different .dtsi.
>
> What do you think?

As the IP cores are the same in all variants, using
"renesas,r7s9210-<something>" should be fine for matching drivers to IP
cores. Same for CONFIG_ARCH_R7S9210.

However, as the actual dies differ between H, M, and L versions, there may
be integration issues to be worked around. So I think it would be wise to
use one more digit in the compatible value at the main SoC level, i.e.
"renesas,r7s92104".
Unless there's a hardware register to detect the version at runtime.
But it seems RZ/A2 doesn't have a Product Register
(PRR), which most other SH/R-Mobile and R-Car SoCs do have?

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 2/2] dt-bindings: arm: Document RZ/A2 SoC DT bindings

[Geert Uytterhoeven]

Hi Chris,

On Fri, Jul 13, 2018 at 1:50 PM Chris Brandt <Chris.Brandt@renesas.com> wrote:
> On Thursday, July 12, 2018, Geert Uytterhoeven wrote:
> > As the IP cores are the same in all variants, using
> > "renesas,r7s9210-<something>" should be fine for matching drivers to IP
> > cores. Same for CONFIG_ARCH_R7S9210.
> >
> > However, as the actual dies differ between H, M, and L versions, there may
> > be integration issues to be worked around. So I think it would be wise to
> > use one more digit in the compatible value at the main SoC level, i.e.
> > "renesas,r7s92104".
> > Unless there's a hardware register to detect the version at runtime.
> > But it seems RZ/A2 doesn't have a Product Register
> > (PRR), which most other SH/R-Mobile and R-Car SoCs do have?
>
> There is an ID register in RZ/A2 that will have a different number for
> each silicon.
> See the first entry in Table 5.6 (BSID register).
>
> Technically, it's not  "PRR" like it's SH/R-Car devices. It's actually
> the boundary scan ID number. All RZ/A1 devices have this too. But with
> RZ/A1, you could only get to this register through JTAG (not by the CPU).
> So for RZ/A2+, they will mirror that register to CPU space.

Cool. So if you add a "renesas,bsid" device node to the dtsi, and add
support for using that to drivers/soc/renesas/renesas-soc.c, then we can
use soc_device_match() to filter on SoC revision, if ever needed.

> So with that said, are we good with CONFIG_ARCH_R7S9210?

Yes, the Kconfig symbol is fine for sure.

Thansk!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds