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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2016-06-13 12:17:54 +0200
committerShawn Guo <shawnguo@kernel.org>2016-06-15 21:42:29 +0800
commitda4fa6fa8016dba54aef2b20793b8e99c6af022d (patch)
tree9c9f901a1173e0b4dce07a1dcd3de7892e14c79c /arch/arm/boot/dts/imx25-pinfunc.h
parent6f0808c48242c77c32f07c3b695ef560bee97938 (diff)
ARM: imx25-pinfunc: document SION being important for MX25_PAD_SD1_CMD__SD1_CMD
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Diffstat (limited to 'arch/arm/boot/dts/imx25-pinfunc.h')
-rw-r--r--arch/arm/boot/dts/imx25-pinfunc.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/boot/dts/imx25-pinfunc.h b/arch/arm/boot/dts/imx25-pinfunc.h
index f96fa2df8f11..953e646f3ea1 100644
--- a/arch/arm/boot/dts/imx25-pinfunc.h
+++ b/arch/arm/boot/dts/imx25-pinfunc.h
@@ -421,6 +421,15 @@
#define MX25_PAD_UART2_CTS__FEC_RX_ERR 0x18c 0x384 0x518 0x12 0x002
#define MX25_PAD_UART2_CTS__GPIO_4_29 0x18c 0x384 0x000 0x15 0x000
+/*
+ * Removing the SION bit from MX25_PAD_SD1_CMD__SD1_CMD breaks detecting an SD
+ * card. According to the i.MX25 reference manual (e.g. Figure 23-2 in IMX25RM
+ * Rev. 2 from 01/2011) this pin is bidirectional. So it seems to be a silicon
+ * bug that configuring the SD1_CMD function doesn't enable the input path for
+ * this pin.
+ * This might have side effects for other hardware units that are connected to
+ * that pin and use the respective function as input.
+ */
#define MX25_PAD_SD1_CMD__SD1_CMD 0x190 0x388 0x000 0x10 0x000
#define MX25_PAD_SD1_CMD__CSPI2_MOSI 0x190 0x388 0x4a0 0x11 0x001
#define MX25_PAD_SD1_CMD__FEC_RDATA2 0x190 0x388 0x50c 0x12 0x002