Re: [PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Shawn Guo]

On Fri, May 25, 2018 at 07:12:38PM -0700, Andrey Smirnov wrote:
> Make sure that MX51_PAD_GPIO1_1 does not remain configure as
> ALT0/SD1_WP (it is out of reset). This is needed because of external
> pull-up resistor attached to that pad that, when left unchanged, will
> drive SD1_WP high preventing eSDHC1/eMMC from working correctly.
> 
> To fix that add a pinmux configuration line configureing the pad to
> function as a GPIO. While we are at it, add a corresponding
> output-high GPIO hog in an effort to minimize current consumption.
> 
> Cc: Nikita Yushchenko 
> Cc: Shawn Guo 
> Cc: Fabio Estevam 
> Cc: Lucas Stach 
> Cc: Chris Healy 
> Cc: Rob Herring 
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: devicet...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov 

Applied, thanks.

Re: [PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Shawn Guo]

On Fri, May 25, 2018 at 07:12:38PM -0700, Andrey Smirnov wrote:
> Make sure that MX51_PAD_GPIO1_1 does not remain configure as
> ALT0/SD1_WP (it is out of reset). This is needed because of external
> pull-up resistor attached to that pad that, when left unchanged, will
> drive SD1_WP high preventing eSDHC1/eMMC from working correctly.
> 
> To fix that add a pinmux configuration line configureing the pad to
> function as a GPIO. While we are at it, add a corresponding
> output-high GPIO hog in an effort to minimize current consumption.
> 
> Cc: Nikita Yushchenko 
> Cc: Shawn Guo 
> Cc: Fabio Estevam 
> Cc: Lucas Stach 
> Cc: Chris Healy 
> Cc: Rob Herring 
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: devicet...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov 

Applied, thanks.

Re: [PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Nikita Yushchenko]

> Make sure that MX51_PAD_GPIO1_1 does not remain configure as
> ALT0/SD1_WP (it is out of reset). This is needed because of external
> pull-up resistor attached to that pad that, when left unchanged, will
> drive SD1_WP high preventing eSDHC1/eMMC from working correctly.
> 
> To fix that add a pinmux configuration line configureing the pad to
> function as a GPIO. While we are at it, add a corresponding
> output-high GPIO hog in an effort to minimize current consumption.
> 
> Cc: Nikita Yushchenko 
> Cc: Shawn Guo 
> Cc: Fabio Estevam 
> Cc: Lucas Stach 
> Cc: Chris Healy 
> Cc: Rob Herring 
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: devicet...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov 

Tested-By: Nikita Yushchenko 

With this patch, eMMC works correctly.

Nikita

Re: [PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Nikita Yushchenko]

> Make sure that MX51_PAD_GPIO1_1 does not remain configure as
> ALT0/SD1_WP (it is out of reset). This is needed because of external
> pull-up resistor attached to that pad that, when left unchanged, will
> drive SD1_WP high preventing eSDHC1/eMMC from working correctly.
> 
> To fix that add a pinmux configuration line configureing the pad to
> function as a GPIO. While we are at it, add a corresponding
> output-high GPIO hog in an effort to minimize current consumption.
> 
> Cc: Nikita Yushchenko 
> Cc: Shawn Guo 
> Cc: Fabio Estevam 
> Cc: Lucas Stach 
> Cc: Chris Healy 
> Cc: Rob Herring 
> Cc: linux-arm-ker...@lists.infradead.org
> Cc: devicet...@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov 

Tested-By: Nikita Yushchenko 

With this patch, eMMC works correctly.

Nikita

[PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Andrey Smirnov]

Make sure that MX51_PAD_GPIO1_1 does not remain configure as
ALT0/SD1_WP (it is out of reset). This is needed because of external
pull-up resistor attached to that pad that, when left unchanged, will
drive SD1_WP high preventing eSDHC1/eMMC from working correctly.

To fix that add a pinmux configuration line configureing the pad to
function as a GPIO. While we are at it, add a corresponding
output-high GPIO hog in an effort to minimize current consumption.

Cc: Nikita Yushchenko 
Cc: Shawn Guo 
Cc: Fabio Estevam 
Cc: Lucas Stach 
Cc: Chris Healy 
Cc: Rob Herring 
Cc: linux-arm-ker...@lists.infradead.org
Cc: devicet...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov 
---

Changes since [v1]:

 - Switched GPIO hog to be output-high

 - Removed whitespace damage

[v1] lkml.kernel.org/r/20180525030153.15986-1-andrew.smir...@gmail.com

 arch/arm/boot/dts/imx51-zii-rdu1.dts | 28 
 1 file changed, 28 insertions(+)

diff --git a/arch/arm/boot/dts/imx51-zii-rdu1.dts 
b/arch/arm/boot/dts/imx51-zii-rdu1.dts
index df9eca94d812..1e343f35a9d9 100644
--- a/arch/arm/boot/dts/imx51-zii-rdu1.dts
+++ b/arch/arm/boot/dts/imx51-zii-rdu1.dts
@@ -476,6 +476,17 @@
status = "okay";
 };
 
+ {
+   unused-sd3-wp-gpio {
+   /*
+* See pinctrl_esdhc1 below for more details on this
+*/
+   gpio-hog;
+   gpios = <1 GPIO_ACTIVE_HIGH>;
+   output-high;
+   };
+};
+
  {
pinctrl-names = "default";
pinctrl-0 = <_i2c2>;
@@ -660,6 +671,23 @@
MX51_PAD_SD1_DATA1__SD1_DATA1   0x20d5
MX51_PAD_SD1_DATA2__SD1_DATA2   0x20d5
MX51_PAD_SD1_DATA3__SD1_DATA3   0x20d5
+   /*
+* GPIO1_1 is not directly used by eSDHC1 in
+* any capacity, but earlier versions of RDU1
+* used that pin as WP GPIO for eSDHC3 and
+* because of that that pad has an external
+* pull-up resistor. This is problematic
+* because out of reset the pad is configured
+* as ALT0 which serves as SD1_WP, which, when
+* pulled high by and external pull-up, will
+* inhibit execution of any write request to
+* attached eMMC device.
+*
+* To avoid this problem we configure the pad
+* to ALT1/GPIO and avoid driving SD1_WP
+* signal high.
+*/
+   MX51_PAD_GPIO1_1__GPIO1_1   0x
>;
};
 
-- 
2.17.0

[PATCH v2] ARM: dts: imx51-zii-rdu1: Make sure SD1_WP is low

[Andrey Smirnov]

Make sure that MX51_PAD_GPIO1_1 does not remain configure as
ALT0/SD1_WP (it is out of reset). This is needed because of external
pull-up resistor attached to that pad that, when left unchanged, will
drive SD1_WP high preventing eSDHC1/eMMC from working correctly.

To fix that add a pinmux configuration line configureing the pad to
function as a GPIO. While we are at it, add a corresponding
output-high GPIO hog in an effort to minimize current consumption.

Cc: Nikita Yushchenko 
Cc: Shawn Guo 
Cc: Fabio Estevam 
Cc: Lucas Stach 
Cc: Chris Healy 
Cc: Rob Herring 
Cc: linux-arm-ker...@lists.infradead.org
Cc: devicet...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrey Smirnov 
---

Changes since [v1]:

 - Switched GPIO hog to be output-high

 - Removed whitespace damage

[v1] lkml.kernel.org/r/20180525030153.15986-1-andrew.smir...@gmail.com

 arch/arm/boot/dts/imx51-zii-rdu1.dts | 28 
 1 file changed, 28 insertions(+)

diff --git a/arch/arm/boot/dts/imx51-zii-rdu1.dts 
b/arch/arm/boot/dts/imx51-zii-rdu1.dts
index df9eca94d812..1e343f35a9d9 100644
--- a/arch/arm/boot/dts/imx51-zii-rdu1.dts
+++ b/arch/arm/boot/dts/imx51-zii-rdu1.dts
@@ -476,6 +476,17 @@
status = "okay";
 };
 
+ {
+   unused-sd3-wp-gpio {
+   /*
+* See pinctrl_esdhc1 below for more details on this
+*/
+   gpio-hog;
+   gpios = <1 GPIO_ACTIVE_HIGH>;
+   output-high;
+   };
+};
+
  {
pinctrl-names = "default";
pinctrl-0 = <_i2c2>;
@@ -660,6 +671,23 @@
MX51_PAD_SD1_DATA1__SD1_DATA1   0x20d5
MX51_PAD_SD1_DATA2__SD1_DATA2   0x20d5
MX51_PAD_SD1_DATA3__SD1_DATA3   0x20d5
+   /*
+* GPIO1_1 is not directly used by eSDHC1 in
+* any capacity, but earlier versions of RDU1
+* used that pin as WP GPIO for eSDHC3 and
+* because of that that pad has an external
+* pull-up resistor. This is problematic
+* because out of reset the pad is configured
+* as ALT0 which serves as SD1_WP, which, when
+* pulled high by and external pull-up, will
+* inhibit execution of any write request to
+* attached eMMC device.
+*
+* To avoid this problem we configure the pad
+* to ALT1/GPIO and avoid driving SD1_WP
+* signal high.
+*/
+   MX51_PAD_GPIO1_1__GPIO1_1   0x
>;
};
 
-- 
2.17.0