RE: [PATCH 01/17] dt-bindings: clock: r9a07g043-cpg: Add power domain IDs

Hi Claudiu,

-----Original Message-----
From: claudiu beznea <claudiu.beznea@tuxon.dev>
Sent: Monday, February 12, 2024 8:02 AM
Subject: Re: [PATCH 01/17] dt-bindings: clock: r9a07g043-cpg: Add power
domain IDs

Hi, Biju,

On 08.02.2024 21:20, Biju Das wrote:

quoted

quoted

-----Original Message-----
From: claudiu beznea <claudiu.beznea@tuxon.dev>
Sent: Thursday, February 8, 2024 4:53 PM
To: Biju Das <biju.das.jz@bp.renesas.com>; geert+renesas@glider.be;
mturquette@baylibre.com; sboyd@kernel.org; robh@kernel.org;
krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org;
magnus.damm@gmail.com; paul.walmsley@sifive.com; palmer@dabbelt.com;
aou@eecs.berkeley.edu
Cc: linux-renesas-soc@vger.kernel.org; linux-clk@vger.kernel.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-
riscv@lists.infradead.org; Claudiu Beznea
[off-list ref]
Subject: Re: [PATCH 01/17] dt-bindings: clock: r9a07g043-cpg: Add
power domain IDs



On 08.02.2024 18:28, Biju Das wrote:

quoted

quoted

-----Original Message-----
From: claudiu beznea <claudiu.beznea@tuxon.dev>
Sent: Thursday, February 8, 2024 3:46 PM
Subject: Re: [PATCH 01/17] dt-bindings: clock: r9a07g043-cpg: Add
power domain IDs

Hi, Biju,

On 08.02.2024 16:30, Biju Das wrote:

quoted

Hi Claudiu,

Thanks for the patch.

quoted

-----Original Message-----
From: Claudiu <claudiu.beznea@tuxon.dev>
Sent: Thursday, February 8, 2024 12:43 PM
Subject: [PATCH 01/17] dt-bindings: clock: r9a07g043-cpg: Add
power domain IDs

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Add power domain IDs for RZ/G2UL (R9A07G043) SoC.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
 include/dt-bindings/clock/r9a07g043-cpg.h | 48
+++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/include/dt-bindings/clock/r9a07g043-cpg.h

b/include/dt- bindings/clock/r9a07g043-cpg.h index
77cde8effdc7..eabfeec7ac37
100644

--- a/include/dt-bindings/clock/r9a07g043-cpg.h
+++ b/include/dt-bindings/clock/r9a07g043-cpg.h

@@ -200,5 +200,53 @@
 #define R9A07G043_AX45MP_CORE0_RESETN	78	/* RZ/Five Only */
 #define R9A07G043_IAX45_RESETN		79	/* RZ/Five Only */

+/* Power domain IDs. */
+#define R9A07G043_PD_ALWAYS_ON		0
+#define R9A07G043_PD_GIC		1
+#define R9A07G043_PD_IA55		2
+#define R9A07G043_PD_MHU		3
+#define R9A07G043_PD_CORESIGHT		4
+#define R9A07G043_PD_SYC		5
+#define R9A07G043_PD_DMAC		6
+#define R9A07G043_PD_GTM0		7
+#define R9A07G043_PD_GTM1		8
+#define R9A07G043_PD_GTM2		9
+#define R9A07G043_PD_MTU		10
+#define R9A07G043_PD_POE3		11
+#define R9A07G043_PD_WDT0		12
+#define R9A07G043_PD_SPI		13
+#define R9A07G043_PD_SDHI0		14
+#define R9A07G043_PD_SDHI1		15
+#define R9A07G043_PD_ISU		16
+#define R9A07G043_PD_CRU		17
+#define R9A07G043_PD_LCDC		18
+#define R9A07G043_PD_SSI0		19
+#define R9A07G043_PD_SSI1		20
+#define R9A07G043_PD_SSI2		21
+#define R9A07G043_PD_SSI3		22
+#define R9A07G043_PD_SRC		23
+#define R9A07G043_PD_USB0		24
+#define R9A07G043_PD_USB1		25
+#define R9A07G043_PD_USB_PHY		26
+#define R9A07G043_PD_ETHER0		27
+#define R9A07G043_PD_ETHER1		28
+#define R9A07G043_PD_I2C0		29
+#define R9A07G043_PD_I2C1		30
+#define R9A07G043_PD_I2C2		31
+#define R9A07G043_PD_I2C3		32
+#define R9A07G043_PD_SCIF0		33
+#define R9A07G043_PD_SCIF1		34
+#define R9A07G043_PD_SCIF2		35
+#define R9A07G043_PD_SCIF3		36
+#define R9A07G043_PD_SCIF4		37
+#define R9A07G043_PD_SCI0		38
+#define R9A07G043_PD_SCI1		39
+#define R9A07G043_PD_IRDA		40
+#define R9A07G043_PD_RSPI0		41
+#define R9A07G043_PD_RSPI1		42
+#define R9A07G043_PD_RSPI2		43
+#define R9A07G043_PD_CANFD		44
+#define R9A07G043_PD_ADC		45
+#define R9A07G043_PD_TSU		46

Not sure from "Table 42.3 Registers for Module Standby Mode"

Power domain ID has to be based on CPG_BUS_***_MSTOP or
CPG_CLKON_*** As former reduces number of IDs??

If I understand correctly your point here, you want me to describe
PM domain in DT with something like:

power-domains = <&cpg CPG_BUS_X_MSTOP>;

MSTOP bits are distinct for each IP.

<&cpg CPG_BUS_MCPU1_MSTOP x>; x =1..9

2=MTU IP

4= GPT

etc...

Is it something work??

It might work. But:

- you have to consider that some IPs have more than one MSTOP bit,
thus, do
  we want to uniquely identify these with all MSTOP bits (thus the
2nd cell
  being a bitmask) or only one is enough?

We can have an encoding in that case 8:16 24 bit entries

I consider this complicates the bindings. I don't consider this is the way
going forward. But I may be wrong. I'll let Geert to give his opinion on
it and change it afterwards, if any.

quoted

quoted

- some HW blocks (e.g. OTFDE_DDR) have no MSTOP bits associated (as of

my

quoted

quoted

  current research), so, only PWRDN

Why do we want to add power domain support for DDR?

To power it up (in case bootloader does any settings in this area) such
that the system will not block while booting.

DDR is enabled by TF_A and is not touched by linux, so why are we adding
Power domain at all in first place. TZC DDR is not accessible in normal world.

So if you don't add DDR power domains, linux doesn't know about any thing about
and it should work like current case.

It is explained in cover letter:

The current DT
bindings were updated with module IDs for the modules listed in tables
with name "Registers for Module Standby Mode" (see HW manual) exception
being RZ/G3S where, *due to the power down functionality*, the DDR,
TZCDDR, OTFDE_DDR were also added, to avoid system being blocked due to
the following lines of code from patch 7/17.

+       /* Prepare for power down the BUSes in power down mode. */
+       if (info->pm_domain_pwrdn_mstop)
+               writel(CPG_PWRDN_MSTOP_ENABLE, priv->base +
+ CPG_PWRDN_MSTOP);

quoted

quoted

- some HW blocks have both MSTOP and PWRDN

That will be an array right?

I'm not sure what you want to say here.

This has to be an array PM domains(multi PM domain) like clocks?

Or 

It can be  handled as sibliling power domain like sibling clocks in RZ/G2L Gbether.

Cheers,
Biju