[PATCH 0/2] pinctrl: sh-pfc: gen2: initialize TDSEL register

[PATCH 0/2] pinctrl: sh-pfc: gen2: initialize TDSEL register

[Wolfram Sang]

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).

Based on an RFC patch for H2 sent two years ago.


Wolfram Sang (2):
  pinctrl: sh-pfc: r8a7790: initialize TDSEL register
  pinctrl: sh-pfc: r8a7794: initialize TDSEL register

 drivers/pinctrl/sh-pfc/pfc-r8a7790.c | 10 ++++++++++
 drivers/pinctrl/sh-pfc/pfc-r8a7794.c |  9 +++++++++
 2 files changed, 19 insertions(+)

-- 
2.19.0

[PATCH 1/2] pinctrl: sh-pfc: r8a7790: initialize TDSEL register

[Wolfram Sang]

Documentation says that some bits in TDSEL must be set (ch 5.3.39 in R-Car H2
v0.91). However, the reset value of the register is 0, so software has to do
it. Add this to the kernel driver to ensure this is really done independent of
firmware versions.

This is needed for some SD cards supporting SDR104 transfer mode. For
me, TDSEL was not initialized by the firmware and I had problems with
the card when re-inserting it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/pinctrl/sh-pfc/pfc-r8a7790.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7790.c b/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
index ab7a35392cd8..c0e679105df9 100644
--- a/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
+++ b/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
@@ -11,6 +11,7 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 
+#include "core.h"
 #include "sh_pfc.h"
 
 /*
@@ -5691,7 +5692,16 @@ static int r8a7790_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *poc
 	return 31 - (pin & 0x1f);
 }
 
+static int r8a7790_pinmux_soc_init(struct sh_pfc *pfc)
+{
+	/* Initialize TDSEL according to datasheet */
+	sh_pfc_write(pfc, 0xe6060088, 0x00155554);
+
+	return 0;
+}
+
 static const struct sh_pfc_soc_operations r8a7790_pinmux_ops = {
+	.init = r8a7790_pinmux_soc_init,
 	.pin_to_pocctrl = r8a7790_pin_to_pocctrl,
 };
 
-- 
2.19.0

Re: [PATCH 1/2] pinctrl: sh-pfc: r8a7790: initialize TDSEL register

[Simon Horman]

On Sun, Oct 28, 2018 at 09:24:56PM +0000, Wolfram Sang wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.39 in R-Car H2
> v0.91). However, the reset value of the register is 0, so software has to do
> it. Add this to the kernel driver to ensure this is really done independent of
> firmware versions.
> 
> This is needed for some SD cards supporting SDR104 transfer mode. For
> me, TDSEL was not initialized by the firmware and I had problems with
> the card when re-inserting it.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Re: [PATCH 1/2] pinctrl: sh-pfc: r8a7790: initialize TDSEL register

[Marek Vasut]

On 10/28/2018 10:24 PM, Wolfram Sang wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.39 in R-Car H2
> v0.91). However, the reset value of the register is 0, so software has to do
> it. Add this to the kernel driver to ensure this is really done independent of
> firmware versions.
> 
> This is needed for some SD cards supporting SDR104 transfer mode. For
> me, TDSEL was not initialized by the firmware and I had problems with
> the card when re-inserting it.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Marek Vasut <marek.vasut@gmail.com>

> ---
>  drivers/pinctrl/sh-pfc/pfc-r8a7790.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7790.c b/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
> index ab7a35392cd8..c0e679105df9 100644
> --- a/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
> +++ b/drivers/pinctrl/sh-pfc/pfc-r8a7790.c
> @@ -11,6 +11,7 @@
>  #include <linux/io.h>
>  #include <linux/kernel.h>
>  
> +#include "core.h"
>  #include "sh_pfc.h"
>  
>  /*
> @@ -5691,7 +5692,16 @@ static int r8a7790_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *poc
>  	return 31 - (pin & 0x1f);
>  }
>  
> +static int r8a7790_pinmux_soc_init(struct sh_pfc *pfc)
> +{
> +	/* Initialize TDSEL according to datasheet */
> +	sh_pfc_write(pfc, 0xe6060088, 0x00155554);
> +
> +	return 0;
> +}
> +
>  static const struct sh_pfc_soc_operations r8a7790_pinmux_ops = {
> +	.init = r8a7790_pinmux_soc_init,
>  	.pin_to_pocctrl = r8a7790_pin_to_pocctrl,
>  };
>  
> 


-- 
Best regards,
Marek Vasut

Re: [PATCH 1/2] pinctrl: sh-pfc: r8a7790: initialize TDSEL register

[Geert Uytterhoeven]

On Sun, Oct 28, 2018 at 10:25 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.39 in R-Car H2
> v0.91). However, the reset value of the register is 0, so software has to do
> it. Add this to the kernel driver to ensure this is really done independent of
> firmware versions.
>
> This is needed for some SD cards supporting SDR104 transfer mode. For
> me, TDSEL was not initialized by the firmware and I had problems with
> the card when re-inserting it.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

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

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] pinctrl: sh-pfc: r8a7794: initialize TDSEL register

[Wolfram Sang]

Documentation says that some bits in TDSEL must be set (ch 5.3.35 in
R-Car E2 v0.5). However, the reset value of the register is 0, so
software has to do it. Add this to the kernel driver to ensure this is
really done independent of firmware versions. This is needed for some SD
cards supporting SDR104 transfer mode.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/pinctrl/sh-pfc/pfc-r8a7794.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
index 6d1e5fdc03f8..8a16053d2bec 100644
--- a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
+++ b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
@@ -5560,7 +5560,16 @@ static int r8a7794_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *poc
 	return -EINVAL;
 }
 
+static int r8a7794_pinmux_soc_init(struct sh_pfc *pfc)
+{
+	/* Initialize TDSEL according to datasheet */
+	sh_pfc_write(pfc, 0xe6060068, 0x55555500);
+
+	return 0;
+}
+
 static const struct sh_pfc_soc_operations r8a7794_pinmux_ops = {
+	.init = r8a7794_pinmux_soc_init,
 	.pin_to_pocctrl = r8a7794_pin_to_pocctrl,
 };
 
-- 
2.19.0

Re: [PATCH 2/2] pinctrl: sh-pfc: r8a7794: initialize TDSEL register

[Simon Horman]

On Sun, Oct 28, 2018 at 09:24:57PM +0000, Wolfram Sang wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.35 in
> R-Car E2 v0.5). However, the reset value of the register is 0, so
> software has to do it. Add this to the kernel driver to ensure this is
> really done independent of firmware versions. This is needed for some SD
> cards supporting SDR104 transfer mode.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

Re: [PATCH 2/2] pinctrl: sh-pfc: r8a7794: initialize TDSEL register

[Marek Vasut]

On 10/28/2018 10:24 PM, Wolfram Sang wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.35 in
> R-Car E2 v0.5). However, the reset value of the register is 0, so
> software has to do it. Add this to the kernel driver to ensure this is
> really done independent of firmware versions. This is needed for some SD
> cards supporting SDR104 transfer mode.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Reviewed-by: Marek Vasut <marek.vasut@gmail.com>

> ---
>  drivers/pinctrl/sh-pfc/pfc-r8a7794.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> index 6d1e5fdc03f8..8a16053d2bec 100644
> --- a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> +++ b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
> @@ -5560,7 +5560,16 @@ static int r8a7794_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *poc
>  	return -EINVAL;
>  }
>  
> +static int r8a7794_pinmux_soc_init(struct sh_pfc *pfc)
> +{
> +	/* Initialize TDSEL according to datasheet */
> +	sh_pfc_write(pfc, 0xe6060068, 0x55555500);
> +
> +	return 0;
> +}
> +
>  static const struct sh_pfc_soc_operations r8a7794_pinmux_ops = {
> +	.init = r8a7794_pinmux_soc_init,
>  	.pin_to_pocctrl = r8a7794_pin_to_pocctrl,
>  };
>  
> 


-- 
Best regards,
Marek Vasut

Re: [PATCH 2/2] pinctrl: sh-pfc: r8a7794: initialize TDSEL register

[Geert Uytterhoeven]

On Sun, Oct 28, 2018 at 10:25 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Documentation says that some bits in TDSEL must be set (ch 5.3.35 in
> R-Car E2 v0.5). However, the reset value of the register is 0, so
> software has to do it. Add this to the kernel driver to ensure this is
> really done independent of firmware versions. This is needed for some SD
> cards supporting SDR104 transfer mode.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

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

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 0/2] pinctrl: sh-pfc: gen2: initialize TDSEL register

[Geert Uytterhoeven]

Hi Wolfram,

CC Chris Paterson

On Sun, Oct 28, 2018 at 10:25 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> 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

But the default non-zero drive strength bit does match the required value
on V2H.

> 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).

Probably we should program TDSEL regardless, to avoid any dependency on
reset state or boot loader.

Note that all RZ/G1 SoCs requires zero TDSEL values, except for RZ/G1C
(which doesn't document required values, just the initial values).
So we need some soc_device_match() handling to obtain the required value.

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