With the current implementation of GPIO hogging and with
gpio-pcf857x is built as module, ethernet doesn't work on boot
and doesn't throw any error/warning to user. Ethernet becomes
operational when inserting gpio-pcf857x module, even this time
there is no error/warning logs to user that ethernet is
operational.
When using with NFS rootfs and gpio-pcf857x as module, board
doesn't boot as it doesn't get any ip address and doesn't throw
any error/warning. To over come this, now cpsw driver tries to
get mode-gpios. When gpio-pcf857x is built as module it will
throw error, so that user can decide either to built in
gpio-pcf857x to continue with nfs boot or choose alternate rootfs
filesystem like sd/ramdisk.
When using mmc/ramdisk as root fs, cpsw will probe defer and
re-probes again when gpio-pcf857x module is inserted and ethernet
becomes operational.
Signed-off-by: Mugunthan V N <mugunthanvnm@xxxxxx>
---
The driver patch is applied to net-next branch (also present in
linux-next) with commit: '1d147ccbfc35 ("drivers: net: cpsw: Add
support to drive gpios for ethernet to be functional")
Tested on DRA72x EVM, logs [1] and pushed a branch [2] for testing
[1]: http://pastebin.ubuntu.com/12514591/
[2]: git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux.git cpsw-mode-gpios-dt
Changes from initial version:
* Modified the commit message to add more information
---
arch/arm/boot/dts/dra72-evm.dts | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/arm/boot/dts/dra72-evm.dts b/arch/arm/boot/dts/dra72-evm.dts
index 6f6bd98..a12c6f4 100644
--- a/arch/arm/boot/dts/dra72-evm.dts
+++ b/arch/arm/boot/dts/dra72-evm.dts
@@ -353,12 +353,6 @@
interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
interrupt-controller;
#interrupt-cells = <2>;
-
- cpsw_sel_s0 {
- gpio-hog;
- gpios = <4 GPIO_ACTIVE_HIGH>;
- output-low;
- };
};
};
@@ -590,6 +584,7 @@
pinctrl-0 = <&cpsw_default>;
pinctrl-1 = <&cpsw_sleep>;
slaves = <1>;
+ mode-gpios = <&pcf_gpio_21 4 GPIO_ACTIVE_HIGH>;
};
&cpsw_emac0 {
--
2.6.0.rc2.10.gf4d9753
--
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