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ARM: bcm2835: add label for uart0

PATCH New Stefan Wahren 3 participants 5 messages Oct 2, 2015 – Oct 15, 2015

Subsystems (3)
Device tree bindings Broadcom BCM2711/BCM2835 Arm architecture Broadcom BCM281XX/BCM11XXX/BCM216XX Arm architecture
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Stefan Wahren

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#0 lore raw

PATCH 1/1 ARM: bcm2835: add label for uart0

This patch adds a label for uart0 to allow changing of uart0 pins.

Signed-off-by Stefan Wahren <[email protected]>
---
 arch/arm/boot/dts/bcm2835.dtsi |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/arm/boot/dts/bcm2835.dtsi +1 -1
index 301c73f..2029394 100644
@@ -92,7 +92,7 @@
 			#interrupt-cells = <2>;
 		};
 
-		uart at 7e201000 {
+		uart0: uart at 7e201000 {
 			compatible = "brcm,bcm2835-pl011", "arm,pl011", "arm,primecell";
 			reg = <0x7e201000 0x1000>;
 			interrupts = <2 25>;
Signature · 1 line
1.7.9.5
#1 lore raw

PATCH 1/1 ARM: bcm2835: add label for uart0

Quoted 3 lines · Stefan Wahren

This patch adds a label for uart0 to allow changing of uart0 pins.

Signed-off-by Stefan Wahren <[email protected]>

This patch seems innocuous, but could you clarify for me how exactly you
change the uart0 pins, and why one would do that?
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#2 lore raw

PATCH 1/1 ARM: bcm2835: add label for uart0

Quoted 9 lines · Eric Anholt
Quoted 4 lines · Stefan Wahren

This patch adds a label for uart0 to allow changing of uart0 pins.

Signed-off-by Stefan Wahren <[email protected]>

This patch seems innocuous, but could you clarify for me how exactly you change the uart0 pins, and why one would do that?

I /assume/ this is so that some other DT file (that includes the edited file) can add some pinctrl-related properties to this DT node, using syntax such as:

&uart0 {
    new content;
};

If so, the patch,

Acked-by Stephen Warren <[email protected]>
author
#3 lore raw

PATCH 1/1 ARM: bcm2835: add label for uart0

Am 07.10.2015 um 04:26 schrieb Stephen Warren:

Quoted 13 lines · Eric Anholt
Quoted 8 lines
Quoted 4 lines · Stefan Wahren

This patch adds a label for uart0 to allow changing of uart0 pins.

Signed-off-by Stefan Wahren <[email protected]>

This patch seems innocuous, but could you clarify for me how exactly you change the uart0 pins, and why one would do that?

I /assume/ this is so that some other DT file (that includes the edited file) can add some pinctrl-related properties to this DT node, using syntax such as:

Quoted 6 lines
&uart0 {
    new content;
};

If so, the patch,

Acked-by Stephen Warren <[email protected]>

Your assumption is correct. In case the UART should be used on a custom board with Raspberry Pi Compute Module and a microcontroller this change is necessary to reference the UART:

&gpio {
// ...

  uart0_pins: uart0_pins {
    brcm,pins = <36 37>;
    brcm,function = <BCM2835_FSEL_ALT2>;

};
}

&uart0 {
pinctrl-names = "default";
pinctrl-0 = <&uart0_pins>;
status = "okay";
};

Thanks

Stefan

#4 lore raw

PATCH 1/1 ARM: bcm2835: add label for uart0

In reply to Stefan Wahren
Quoted 3 lines · Stefan Wahren

This patch adds a label for uart0 to allow changing of uart0 pins.

Signed-off-by Stefan Wahren <[email protected]>

Pulled to bcm2835-dt-next with Stephen's ack.
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