[PATCHv4 0/7] ARM: sunxi: Extend UART support for Allwinner SoCs

[PATCHv4 0/7] ARM: sunxi: Extend UART support for Allwinner SoCs

[Maxime Ripard]

Hi,

This patchset reworks a bit the UART support that is found in the DT
for Allwinner SoCs, which was quite limited until now.

It first switches to using the clocks property, then rework a bit the
DTSI to have only the UART available in the A10 and the A13 (the A10
has 8 UARTs, while A13 has only the uart1 and uart3).

Thanks,
Maxime

Changes from v3:
  - Renamed uart nodes to serial
  - Reworked the patch for 8250_dw to use the IS_ERR macro for clocks error
    checking

Changes from v2:
  - Reworked Emilio's patch according to Heikki Krogerus' review to enable the
    use of the clock framework even when not using the dt

Emilio L?pez (1):
  serial: 8250_dw: add support for clk api

Maxime Ripard (6):
  ARM: sunxi: dt: Use clocks property instead of clock-frequency for
    the UARTs
  ARM: sunxi: Rename uart nodes to serial
  ARM: sunxi: dt: Move uart0 to sun4i-a10.dtsi
  ARM: sunxi: dt: Add uart3 dt node
  ARM: sunxi: dt: Add A10 UARTs to the dtsi.
  ARM: sunxi: hackberry: Add UART muxing

 arch/arm/boot/dts/sun4i-a10-cubieboard.dts |    4 +-
 arch/arm/boot/dts/sun4i-a10-hackberry.dts  |    4 +-
 arch/arm/boot/dts/sun4i-a10.dtsi           |   60 ++++++++++++++++++++++++++++
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts  |    2 +-
 arch/arm/boot/dts/sunxi.dtsi               |   16 ++++----
 drivers/tty/serial/8250/8250_dw.c          |   33 ++++++++++-----
 6 files changed, 98 insertions(+), 21 deletions(-)

-- 
1.7.10.4

[PATCH 1/7] serial: 8250_dw: add support for clk api

[Maxime Ripard]

From: Emilio L?pez <emilio@elopez.com.ar>

This commit implements support for using the clk api; this lets us use
the "clocks" property with device tree, instead of having to use
clock-frequency.

Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
---
 drivers/tty/serial/8250/8250_dw.c |   33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index db0e66f..3dedd24 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -26,6 +26,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/clk.h>
 
 #include "8250.h"
 
@@ -55,8 +56,9 @@
 
 
 struct dw8250_data {
-	int	last_lcr;
-	int	line;
+	int		last_lcr;
+	int		line;
+	struct clk	*clk;
 };
 
 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
@@ -136,8 +138,13 @@ static int dw8250_probe_of(struct uart_port *p)
 	if (!of_property_read_u32(np, "reg-shift", &val))
 		p->regshift = val;
 
+	/* clock got configured through clk api, all done */
+	if (IS_ERR(p->uartclk))
+		return 0;
+
+	/* try to find out clock frequency from DT as fallback */
 	if (of_property_read_u32(np, "clock-frequency", &val)) {
-		dev_err(p->dev, "no clock-frequency property set\n");
+		dev_err(p->dev, "clk or clock-frequency not defined\n");
 		return -EINVAL;
 	}
 	p->uartclk = val;
@@ -294,9 +301,20 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!uart.port.membase)
 		return -ENOMEM;
 
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(data->clk)) {
+		clk_prepare_enable(data->clk);
+		uart.port.uartclk = clk_get_rate(data->clk);
+	}
+
 	uart.port.iotype = UPIO_MEM;
 	uart.port.serial_in = dw8250_serial_in;
 	uart.port.serial_out = dw8250_serial_out;
+	uart.port.private_data = data;
 
 	dw8250_setup_port(&uart);
 
@@ -312,12 +330,6 @@ static int dw8250_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	uart.port.private_data = data;
-
 	data->line = serial8250_register_8250_port(&uart);
 	if (data->line < 0)
 		return data->line;
@@ -333,6 +345,9 @@ static int dw8250_remove(struct platform_device *pdev)
 
 	serial8250_unregister_port(data->line);
 
+	if (!IS_ERR(data->clk))
+		clk_disable_unprepare(data->clk);
+
 	return 0;
 }
 
-- 
1.7.10.4

[PATCH 1/7] serial: 8250_dw: add support for clk api

[Maxime Ripard]

Hi,

Le 19/03/2013 11:35, Maxime Ripard a ?crit :
> From: Emilio L?pez <emilio@elopez.com.ar>
> 
> This commit implements support for using the clk api; this lets us use
> the "clocks" property with device tree, instead of having to use
> clock-frequency.
> 
> Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
> ---
>  drivers/tty/serial/8250/8250_dw.c |   33 ++++++++++++++++++++++++---------
>  1 file changed, 24 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
> index db0e66f..3dedd24 100644
> --- a/drivers/tty/serial/8250/8250_dw.c
> +++ b/drivers/tty/serial/8250/8250_dw.c
> @@ -26,6 +26,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/slab.h>
>  #include <linux/acpi.h>
> +#include <linux/clk.h>
>  
>  #include "8250.h"
>  
> @@ -55,8 +56,9 @@
>  
>  
>  struct dw8250_data {
> -	int	last_lcr;
> -	int	line;
> +	int		last_lcr;
> +	int		line;
> +	struct clk	*clk;
>  };
>  
>  static void dw8250_serial_out(struct uart_port *p, int offset, int value)
> @@ -136,8 +138,13 @@ static int dw8250_probe_of(struct uart_port *p)
>  	if (!of_property_read_u32(np, "reg-shift", &val))
>  		p->regshift = val;
>  
> +	/* clock got configured through clk api, all done */
> +	if (IS_ERR(p->uartclk))

Hmm, I messed up here.

I'll resend a new version of this mail without this IS_ERR call

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH] serial: 8250_dw: add support for clk api

[Maxime Ripard]

From: Emilio L?pez <emilio@elopez.com.ar>

This commit implements support for using the clk api; this lets us use
the "clocks" property with device tree, instead of having to use
clock-frequency.

Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
---
 drivers/tty/serial/8250/8250_dw.c |   33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index db0e66f..3dedd24 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -26,6 +26,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/clk.h>
 
 #include "8250.h"
 
@@ -55,8 +56,9 @@
 
 
 struct dw8250_data {
-	int	last_lcr;
-	int	line;
+	int		last_lcr;
+	int		line;
+	struct clk	*clk;
 };
 
 static void dw8250_serial_out(struct uart_port *p, int offset, int value)
@@ -136,8 +138,13 @@ static int dw8250_probe_of(struct uart_port *p)
 	if (!of_property_read_u32(np, "reg-shift", &val))
 		p->regshift = val;
 
+	/* clock got configured through clk api, all done */
+	if (p->uartclk)
+		return 0;
+
+	/* try to find out clock frequency from DT as fallback */
 	if (of_property_read_u32(np, "clock-frequency", &val)) {
-		dev_err(p->dev, "no clock-frequency property set\n");
+		dev_err(p->dev, "clk or clock-frequency not defined\n");
 		return -EINVAL;
 	}
 	p->uartclk = val;
@@ -294,9 +301,20 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!uart.port.membase)
 		return -ENOMEM;
 
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(data->clk)) {
+		clk_prepare_enable(data->clk);
+		uart.port.uartclk = clk_get_rate(data->clk);
+	}
+
 	uart.port.iotype = UPIO_MEM;
 	uart.port.serial_in = dw8250_serial_in;
 	uart.port.serial_out = dw8250_serial_out;
+	uart.port.private_data = data;
 
 	dw8250_setup_port(&uart);
 
@@ -312,12 +330,6 @@ static int dw8250_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	uart.port.private_data = data;
-
 	data->line = serial8250_register_8250_port(&uart);
 	if (data->line < 0)
 		return data->line;
@@ -333,6 +345,9 @@ static int dw8250_remove(struct platform_device *pdev)
 
 	serial8250_unregister_port(data->line);
 
+	if (!IS_ERR(data->clk))
+		clk_disable_unprepare(data->clk);
+
 	return 0;
 }
 
-- 
1.7.10.4

[PATCH] serial: 8250_dw: add support for clk api

[Heikki Krogerus]

On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
> From: Emilio L?pez <emilio@elopez.com.ar>
> 
> This commit implements support for using the clk api; this lets us use
> the "clocks" property with device tree, instead of having to use
> clock-frequency.
> 
> Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>

FWIW,

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

-- 
heikki

[PATCH] serial: 8250_dw: add support for clk api

[Maxime Ripard]

Hi Greg,

Le 21/03/2013 09:47, Heikki Krogerus a ?crit :
> On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
>> From: Emilio L?pez <emilio@elopez.com.ar>
>>
>> This commit implements support for using the clk api; this lets us use
>> the "clocks" property with device tree, instead of having to use
>> clock-frequency.
>>
>> Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
> 
> FWIW,
> 
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Would you consider merging this patch, or do you have additional comments?

We have several patch series that depends on this one that I'd like to
see included in 3.10, and we begin to see the end of the 3.9 release cycle.

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH] serial: 8250_dw: add support for clk api

[Greg Kroah-Hartman]

On Tue, Mar 26, 2013 at 11:35:18AM +0100, Maxime Ripard wrote:
> Hi Greg,
> 
> Le 21/03/2013 09:47, Heikki Krogerus a ?crit :
> > On Tue, Mar 19, 2013 at 11:52:49AM +0100, Maxime Ripard wrote:
> >> From: Emilio L?pez <emilio@elopez.com.ar>
> >>
> >> This commit implements support for using the clk api; this lets us use
> >> the "clocks" property with device tree, instead of having to use
> >> clock-frequency.
> >>
> >> Signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
> > 
> > FWIW,
> > 
> > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> 
> Would you consider merging this patch, or do you have additional comments?
> 
> We have several patch series that depends on this one that I'd like to
> see included in 3.10, and we begin to see the end of the 3.9 release cycle.

You resent one patch, in the middle of a 7 patch series, with me on the
 cc: and somehow expected me to know that I was supposed to apply it?

Please be specific and realistic with your requests.

Resend it if you feel I should apply it.

greg k-h

[PATCH 2/7] ARM: sunxi: dt: Use clocks property instead of clock-frequency for the UARTs

[Maxime Ripard]

It will be especially useful when we will have the clock definitions in
the device tree.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio L?pez <emilio@elopez.com.ar>
Tested-by: Emilio L?pez <emilio@elopez.com.ar>
---
 arch/arm/boot/dts/sunxi.dtsi |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/sunxi.dtsi b/arch/arm/boot/dts/sunxi.dtsi
index 8b36abe..791c02a 100644
--- a/arch/arm/boot/dts/sunxi.dtsi
+++ b/arch/arm/boot/dts/sunxi.dtsi
@@ -65,7 +65,7 @@
 			interrupts = <1>;
 			reg-shift = <2>;
 			reg-io-width = <4>;
-			clock-frequency = <24000000>;
+			clocks = <&osc>;
 			status = "disabled";
 		};
 
@@ -75,7 +75,7 @@
 			interrupts = <2>;
 			reg-shift = <2>;
 			reg-io-width = <4>;
-			clock-frequency = <24000000>;
+			clocks = <&osc>;
 			status = "disabled";
 		};
 	};
-- 
1.7.10.4

[PATCH 3/7] ARM: sunxi: Rename uart nodes to serial

[Maxime Ripard]

The other architecture use serial at address for their uart nodes, so
rename our uart dt nodes to be consistent

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun4i-a10-cubieboard.dts |    4 ++--
 arch/arm/boot/dts/sun4i-a10-hackberry.dts  |    2 +-
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts  |    2 +-
 arch/arm/boot/dts/sunxi.dtsi               |    4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm/boot/dts/sun4i-a10-cubieboard.dts b/arch/arm/boot/dts/sun4i-a10-cubieboard.dts
index 88e2dc1..cd06a3c 100644
--- a/arch/arm/boot/dts/sun4i-a10-cubieboard.dts
+++ b/arch/arm/boot/dts/sun4i-a10-cubieboard.dts
@@ -36,11 +36,11 @@
 			};
 		};
 
-		uart0: uart at 01c28000 {
+		uart0: serial at 01c28000 {
 			status = "okay";
 		};
 
-		uart1: uart at 01c28400 {
+		uart1: serial at 01c28400 {
 			status = "okay";
 		};
 	};
diff --git a/arch/arm/boot/dts/sun4i-a10-hackberry.dts b/arch/arm/boot/dts/sun4i-a10-hackberry.dts
index f84549a..9ab6875 100644
--- a/arch/arm/boot/dts/sun4i-a10-hackberry.dts
+++ b/arch/arm/boot/dts/sun4i-a10-hackberry.dts
@@ -23,7 +23,7 @@
 	};
 
 	soc {
-		uart0: uart at 01c28000 {
+		uart0: serial at 01c28000 {
 			status = "okay";
 		};
 	};
diff --git a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
index 33d1c7e..f1579a8 100644
--- a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
+++ b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
@@ -32,7 +32,7 @@
 			};
 		};
 
-		uart1: uart at 01c28400 {
+		uart1: serial at 01c28400 {
 			pinctrl-names = "default";
 			pinctrl-0 = <&uart1_pins_b>;
 			status = "okay";
diff --git a/arch/arm/boot/dts/sunxi.dtsi b/arch/arm/boot/dts/sunxi.dtsi
index 791c02a..1e0f4b5 100644
--- a/arch/arm/boot/dts/sunxi.dtsi
+++ b/arch/arm/boot/dts/sunxi.dtsi
@@ -59,7 +59,7 @@
 			#interrupt-cells = <1>;
 		};
 
-		uart0: uart at 01c28000 {
+		uart0: serial at 01c28000 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28000 0x400>;
 			interrupts = <1>;
@@ -69,7 +69,7 @@
 			status = "disabled";
 		};
 
-		uart1: uart at 01c28400 {
+		uart1: serial at 01c28400 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28400 0x400>;
 			interrupts = <2>;
-- 
1.7.10.4

[PATCH 4/7] ARM: sunxi: dt: Move uart0 to sun4i-a10.dtsi

[Maxime Ripard]

The UART0 is only available on the Allwinner A10 SoCs, and not on the
A13, so move the uart0 node to sun4i-a10.dtsi.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio L?pez <emilio@elopez.com.ar>
Tested-by: Emilio L?pez <emilio@elopez.com.ar>
---
 arch/arm/boot/dts/sun4i-a10.dtsi |   10 ++++++++++
 arch/arm/boot/dts/sunxi.dtsi     |   10 ----------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm/boot/dts/sun4i-a10.dtsi b/arch/arm/boot/dts/sun4i-a10.dtsi
index 03d2b53..b605672 100644
--- a/arch/arm/boot/dts/sun4i-a10.dtsi
+++ b/arch/arm/boot/dts/sun4i-a10.dtsi
@@ -47,5 +47,15 @@
 				allwinner,pull = <0>;
 			};
 		};
+
+		uart0: serial at 01c28000 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c28000 0x400>;
+			interrupts = <1>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/sunxi.dtsi b/arch/arm/boot/dts/sunxi.dtsi
index 1e0f4b5..cf53c43 100644
--- a/arch/arm/boot/dts/sunxi.dtsi
+++ b/arch/arm/boot/dts/sunxi.dtsi
@@ -59,16 +59,6 @@
 			#interrupt-cells = <1>;
 		};
 
-		uart0: serial at 01c28000 {
-			compatible = "snps,dw-apb-uart";
-			reg = <0x01c28000 0x400>;
-			interrupts = <1>;
-			reg-shift = <2>;
-			reg-io-width = <4>;
-			clocks = <&osc>;
-			status = "disabled";
-		};
-
 		uart1: serial at 01c28400 {
 			compatible = "snps,dw-apb-uart";
 			reg = <0x01c28400 0x400>;
-- 
1.7.10.4

[PATCH 5/7] ARM: sunxi: dt: Add uart3 dt node

[Maxime Ripard]

Both A10 and A13 Allwinner SoCs have a Synopsys APB uart3 device
available, so add it to the sunxi.dtsi file

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio L?pez <emilio@elopez.com.ar>
---
 arch/arm/boot/dts/sunxi.dtsi |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/sunxi.dtsi b/arch/arm/boot/dts/sunxi.dtsi
index cf53c43..a85030b 100644
--- a/arch/arm/boot/dts/sunxi.dtsi
+++ b/arch/arm/boot/dts/sunxi.dtsi
@@ -68,5 +68,15 @@
 			clocks = <&osc>;
 			status = "disabled";
 		};
+
+		uart3: serial at 01c28c00 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c28c00 0x400>;
+			interrupts = <4>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
 	};
 };
-- 
1.7.10.4

[PATCH 6/7] ARM: sunxi: dt: Add A10 UARTs to the dtsi.

[Maxime Ripard]

The Allwinner A10 SoC has 8 available UARTs, which is 6 more than on the
A13, so add the missing UARTs to the sun4i-a10 dtsi.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio L?pez <emilio@elopez.com.ar>
---
 arch/arm/boot/dts/sun4i-a10.dtsi |   50 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/arch/arm/boot/dts/sun4i-a10.dtsi b/arch/arm/boot/dts/sun4i-a10.dtsi
index b605672..68a27fc 100644
--- a/arch/arm/boot/dts/sun4i-a10.dtsi
+++ b/arch/arm/boot/dts/sun4i-a10.dtsi
@@ -57,5 +57,55 @@
 			clocks = <&osc>;
 			status = "disabled";
 		};
+
+		uart2: serial at 01c28800 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c28800 0x400>;
+			interrupts = <3>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
+
+		uart4: serial at 01c29000 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c29000 0x400>;
+			interrupts = <17>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
+
+		uart5: serial at 01c29400 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c29400 0x400>;
+			interrupts = <18>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
+
+		uart6: serial at 01c29800 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c29800 0x400>;
+			interrupts = <19>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
+
+		uart7: serial at 01c29c00 {
+			compatible = "snps,dw-apb-uart";
+			reg = <0x01c29c00 0x400>;
+			interrupts = <20>;
+			reg-shift = <2>;
+			reg-io-width = <4>;
+			clocks = <&osc>;
+			status = "disabled";
+		};
 	};
 };
-- 
1.7.10.4

[PATCH 7/7] ARM: sunxi: hackberry: Add UART muxing

[Maxime Ripard]

We previously relied on the bootloader to do the muxing of the UART for
the Hackberry. Don't rely on it anymore and use pinctrl.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio L?pez <emilio@elopez.com.ar>
---
 arch/arm/boot/dts/sun4i-a10-hackberry.dts |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/sun4i-a10-hackberry.dts b/arch/arm/boot/dts/sun4i-a10-hackberry.dts
index 9ab6875..2046000 100644
--- a/arch/arm/boot/dts/sun4i-a10-hackberry.dts
+++ b/arch/arm/boot/dts/sun4i-a10-hackberry.dts
@@ -24,6 +24,8 @@
 
 	soc {
 		uart0: serial at 01c28000 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&uart0_pins_a>;
 			status = "okay";
 		};
 	};
-- 
1.7.10.4