| Message ID | 20180526021238.30753-1-andrew.smirnov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> 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 <nikita.yoush@cogentembedded.com> > Cc: Shawn Guo <shawnguo@kernel.org> > Cc: Fabio Estevam <fabio.estevam@nxp.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Chris Healy <cphealy@gmail.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: devicetree@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Tested-By: Nikita Yushchenko <nikita.yoush@cogentembedded.com Tested on 8.9'' RDU1. Without this patch, eMMC does not work, get [ 40.801367] mmc0: Timeout waiting for hardware interrupt. [ 40.806789] mmc0: sdhci: ============ SDHCI REGISTER DUMP =========== ... <dump follows> With this patch, eMMC works correctly. Nikita
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 <nikita.yoush@cogentembedded.com> > Cc: Shawn Guo <shawnguo@kernel.org> > Cc: Fabio Estevam <fabio.estevam@nxp.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Chris Healy <cphealy@gmail.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: devicetree@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Applied, thanks.
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"; }; +&gpio1 { + unused-sd3-wp-gpio { + /* + * See pinctrl_esdhc1 below for more details on this + */ + gpio-hog; + gpios = <1 GPIO_ACTIVE_HIGH>; + output-high; + }; +}; + &i2c2 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_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 0x0000 >; };
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 <nikita.yoush@cogentembedded.com> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Chris Healy <cphealy@gmail.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> --- Changes since [v1]: - Switched GPIO hog to be output-high - Removed whitespace damage [v1] lkml.kernel.org/r/20180525030153.15986-1-andrew.smirnov@gmail.com arch/arm/boot/dts/imx51-zii-rdu1.dts | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)