RE: [PATCH v2 0/2] pinctrl: sh-pfc: gen2: initialize TDSEL register for ES1.0

From: Chris Paterson <Chris.Paterson2@renesas.com>
To: Wolfram Sang <wsa+renesas@sang-engineering.com>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>
Cc: "linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>
Subject: RE: [PATCH v2 0/2] pinctrl: sh-pfc: gen2: initialize TDSEL register for ES1.0
Date: Tue, 8 Jan 2019 11:18:55 +0000	[thread overview]
Message-ID: <TYAPR01MB2285DCB1EA42F6B4FE33E1C3B78A0@TYAPR01MB2285.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <20190107221320.14930-1-wsa+renesas@sang-engineering.com>

Hello Wolfram,

Thank you for the heads up.

> From: Wolfram Sang <wsa+renesas@sang-engineering.com>
> Sent: 07 January 2019 22:13
> 
> During our SDHI hackathon, we found that Lager was the only Gen2 board
> having issues with a stubborn SD card. The issue went away when setting
> TDSEL to the expected value mentioned in the H2 documentation which is
> sadly not the default value. M2-W, M2-N, and V2H have an expected value
> of 0 for TDSEL, so this is why they likely work out of the box (V2H has
> non-zero drive strength bit, though). I can't verify those SoCs here, no
> boards. E2 has a non-zero expected value as well, so we fix it in this
> patch series as well (although on my board the bootloader prepares TDSEL
> correctly, but let's not rely on that).
> 
> Changes since V1:
> 
> * we discussed this with the HW team internally and concluded this is only
>   needed for ES1.0 versions of these SoCs. So, setting TDSEL is now
>   whitelisted using soc_device_match.
> 
> * Chris added to CC
>   For two reasons: first, to give him a chance to test this so we don't
>   break the RZ series.

Neither RZ/G1[HE] devices are based on ES1.0 so these patches shouldn't have an effect.
According to the RZ/G1 H/W manuals, all RZ/G1[HMNE] devices are expecting 0 for TDSEL.

> Second, according to Geert, R-Car E2X and RZ/G1C
>   might have the same 'non-zero default value of TDSEL' problem and maybe
>   need fixing, too. But we don't have HW to check/test this.

Geert is correct. We'll have to look into it.

Kind regards, Chris

> 
> Looking forward to comments!
> 
> Thanks,
> 
>    Wolfram
> 
> 
> Wolfram Sang (2):
>   pinctrl: sh-pfc: r8a7790: initialize TDSEL register for ES1.0
>   pinctrl: sh-pfc: r8a7794: initialize TDSEL register for ES1.0
> 
>  drivers/pinctrl/sh-pfc/pfc-r8a7790.c | 17 +++++++++++++++++
>  drivers/pinctrl/sh-pfc/pfc-r8a7794.c | 16 ++++++++++++++++
>  2 files changed, 33 insertions(+)
> 
> --
> 2.11.0