Gpio reset handling
Michal Simek
monstr at monstr.eu
Wed Sep 16 04:32:49 EST 2009
Hi All,
I would like to find out proper way how to handle xilinx reset gpio.
We are using gpio for soft reset.
I read led.txt in Documentation and currently are used/supported some triggers
but reset is not there.
Led gpio is clear because example is in kernel (xpedite5301.dts for example)
Here is description for mixed reset/heartbeat/led gpio
1. line - soft reset
2. line - phy reset for example or any different one
3. line - heartbeat
4. line - led
Not sure if is first line from 1 or 0 - but doesn't matter right now.
gpio_res: gpio at 81400000 {
compatible = "xlnx,xps-gpio-1.00.a";
interrupt-parent = <&xps_intc_0>;
interrupts = < 7 2 >;
reg = < 0x81400000 0x10000 >;
...
xlnx,gpio-width = <0x8>;
...
} ;
gpio-leds {
compatible = "gpio-leds";
heartbeat {
label = "Heartbeat";
gpios = <&gpio_res 4 1>;
linux,default-trigger = "heartbeat";
}
green {
label = "Green"
gpios = <&gpio_res 5 1>;
}
}
Ok and here about description of reset port
I see two option to write new trigger
1. new reset trigger and add it to gpio-leds node - but this should be in gpio-leds node which make
no sense to me
reset {
label = "Heartbeat";
gpios = <&gpio_res 3 1>;
linux,default-trigger = "reset";
}
2. create own reset node
reset {
compatible = "gpio-reset";
reset0 {
label "Soft reset";
gpios = <&gpio_res 1 1>;
}
reset1 {
label "Phy reset";
gpios = <&gpio_res 2 1>;
}
}
For this node there should be better reset description not just label with different description.
I expect that it will be useful soft and hard reset and maybe you can find some others.
Thanks for you help,
Michal
--
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian
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