[PATCH v2 0/4] clk: sunxi: add A20 external output clock support

[PATCH v2 0/4] clk: sunxi: add A20 external output clock support

[Chen-Yu Tsai]

Hi everyone,

This is a resend of A20 external output clock support patch
series v2.

The patch series builds upon Emilio's clock series, and adds
support for external output clocks on the Allwinner A20 SoC.
The outputs can be used to supply a stable clock to external
modules, such as WiFi or Bluetooth.

Mike Turquette has already taken patch #1 via Emilio's pull
request.

Changes since v1:

  - Add clock binding to sunxi clock DT binding documentation
  - Rename clock nodes to match device tree conventions
  - Add commit message for pin function/mux commits
  - Add comments to pin functions


Cheers,
ChenYu


Chen-Yu Tsai (4):
  clk: sunxi: Allwinner A20 output clock support
  ARM: dts: sun7i: external clock outputs
  pinctrl: sunxi: Add Allwinner A20 clock output pin functions
  ARM: dts: sun7i: Add pin muxing options for clock outputs

 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 arch/arm/boot/dts/sun7i-a20.dtsi                  | 41 ++++++++++++++++
 drivers/clk/sunxi/clk-sunxi.c                     | 57 +++++++++++++++++++++++
 drivers/pinctrl/pinctrl-sunxi-pins.h              |  2 +
 4 files changed, 101 insertions(+)

-- 
1.8.5.2

[PATCH v2 1/4] clk: sunxi: Allwinner A20 output clock support

[Chen-Yu Tsai]

This patch adds support for the external clock outputs on the
Allwinner A20 SoC. The clock outputs are similar to "module 0"
type clocks, with different offsets and widths for clock factors.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/clk-sunxi.c                     | 57 +++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 46d8433..c2cb762 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -36,6 +36,7 @@ Required properties:
 	"allwinner,sun6i-a31-apb2-div-clk" - for the APB2 gates on A31
 	"allwinner,sun6i-a31-apb2-gates-clk" - for the APB2 gates on A31
 	"allwinner,sun4i-mod0-clk" - for the module 0 family of clocks
+	"allwinner,sun7i-a20-out-clk" - for the external output clocks
 
 Required properties for all clocks:
 - reg : shall be the control register address for the clock.
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 25d99b6..19d9e9e 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -330,6 +330,47 @@ static void sun4i_get_mod0_factors(u32 *freq, u32 parent_rate,
 
 
 /**
+ * sun7i_a20_get_out_factors() - calculates m, p factors for CLK_OUT_A/B
+ * CLK_OUT rate is calculated as follows
+ * rate = (parent_rate >> p) / (m + 1);
+ */
+
+static void sun7i_a20_get_out_factors(u32 *freq, u32 parent_rate,
+				      u8 *n, u8 *k, u8 *m, u8 *p)
+{
+	u8 div, calcm, calcp;
+
+	/* These clocks can only divide, so we will never be able to achieve
+	 * frequencies higher than the parent frequency */
+	if (*freq > parent_rate)
+		*freq = parent_rate;
+
+	div = parent_rate / *freq;
+
+	if (div < 32)
+		calcp = 0;
+	else if (div / 2 < 32)
+		calcp = 1;
+	else if (div / 4 < 32)
+		calcp = 2;
+	else
+		calcp = 3;
+
+	calcm = DIV_ROUND_UP(div, 1 << calcp);
+
+	*freq = (parent_rate >> calcp) / calcm;
+
+	/* we were called to round the frequency, we can now return */
+	if (n == NULL)
+		return;
+
+	*m = calcm - 1;
+	*p = calcp;
+}
+
+
+
+/**
  * sunxi_factors_clk_setup() - Setup function for factor clocks
  */
 
@@ -384,6 +425,14 @@ static struct clk_factors_config sun4i_mod0_config = {
 	.pwidth = 2,
 };
 
+/* user manual says "n" but it's really "p" */
+static struct clk_factors_config sun7i_a20_out_config = {
+	.mshift = 8,
+	.mwidth = 5,
+	.pshift = 20,
+	.pwidth = 2,
+};
+
 static const struct factors_data sun4i_pll1_data __initconst = {
 	.enable = 31,
 	.table = &sun4i_pll1_config,
@@ -414,6 +463,13 @@ static const struct factors_data sun4i_mod0_data __initconst = {
 	.getter = sun4i_get_mod0_factors,
 };
 
+static const struct factors_data sun7i_a20_out_data __initconst = {
+	.enable = 31,
+	.mux = 24,
+	.table = &sun7i_a20_out_config,
+	.getter = sun7i_a20_get_out_factors,
+};
+
 static struct clk * __init sunxi_factors_clk_setup(struct device_node *node,
 						const struct factors_data *data)
 {
@@ -912,6 +968,7 @@ static const struct of_device_id clk_factors_match[] __initconst = {
 	{.compatible = "allwinner,sun6i-a31-pll1-clk", .data = &sun6i_a31_pll1_data,},
 	{.compatible = "allwinner,sun4i-apb1-clk", .data = &sun4i_apb1_data,},
 	{.compatible = "allwinner,sun4i-mod0-clk", .data = &sun4i_mod0_data,},
+	{.compatible = "allwinner,sun7i-a20-out-clk", .data = &sun7i_a20_out_data,},
 	{}
 };
 
-- 
1.8.5.2

[PATCH v2 2/4] ARM: dts: sun7i: external clock outputs

[Chen-Yu Tsai]

This commit adds the two external clock outputs available on A20 to
its device tree. A dummy fixed factor clock is also added to serve as
the first input of the clock outputs, which according to AW's A20 user
manual, is the 24MHz oscillator divided by 750.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun7i-a20.dtsi | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 4c25f81..f255a49 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -302,6 +302,33 @@
 			clocks = <&osc24M>, <&pll6 2>, <&pll5 1>;
 			clock-output-names = "mbus";
 		};
+
+		/*
+		 * Dummy clock used by output clocks
+		 */
+		osc24M_32k: osc24M_32k {
+			#clock-cells = <0>;
+			compatible = "fixed-factor-clock";
+			clock-div = <750>;
+			clock-mult = <1>;
+			clocks = <&osc24M>;
+		};
+
+		clk_out_a: clk at 01c201f0 {
+			#clock-cells = <0>;
+			compatible = "allwinner,sun7i-a20-out-clk";
+			reg = <0x01c201f0 0x4>;
+			clocks = <&osc24M_32k>, <&osc32k>, <&osc24M>;
+			clock-output-names = "clk_out_a";
+		};
+
+		clk_out_b: clk at 01c201f4 {
+			#clock-cells = <0>;
+			compatible = "allwinner,sun7i-a20-out-clk";
+			reg = <0x01c201f4 0x4>;
+			clocks = <&osc24M_32k>, <&osc32k>, <&osc24M>;
+			clock-output-names = "clk_out_b";
+		};
 	};
 
 	soc at 01c00000 {
-- 
1.8.5.2

[PATCH v2 3/4] pinctrl: sunxi: Add Allwinner A20 clock output pin functions

[Chen-Yu Tsai]

This patch adds the clock output pin functions on the A20.
The 2 pins can output a configurable clock to be used by
external modules. This is used on the CubieTruck, to supply
a 32768 Hz low power clock to the onboard Wifi+BT module.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 drivers/pinctrl/pinctrl-sunxi-pins.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/pinctrl/pinctrl-sunxi-pins.h b/drivers/pinctrl/pinctrl-sunxi-pins.h
index 2c7446a..6fd8d4d 100644
--- a/drivers/pinctrl/pinctrl-sunxi-pins.h
+++ b/drivers/pinctrl/pinctrl-sunxi-pins.h
@@ -3774,12 +3774,14 @@ static const struct sunxi_desc_pin sun7i_a20_pins[] = {
 		  SUNXI_FUNCTION(0x1, "gpio_out"),
 		  SUNXI_FUNCTION(0x2, "spi0"),		/* MOSI */
 		  SUNXI_FUNCTION(0x3, "uart6"),		/* TX */
+		  SUNXI_FUNCTION(0x4, "clk_out_a"),	/* CLK_OUT_A */
 		  SUNXI_FUNCTION_IRQ(0x5, 24)),		/* EINT24 */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PI13,
 		  SUNXI_FUNCTION(0x0, "gpio_in"),
 		  SUNXI_FUNCTION(0x1, "gpio_out"),
 		  SUNXI_FUNCTION(0x2, "spi0"),		/* MISO */
 		  SUNXI_FUNCTION(0x3, "uart6"),		/* RX */
+		  SUNXI_FUNCTION(0x4, "clk_out_b"),	/* CLK_OUT_B */
 		  SUNXI_FUNCTION_IRQ(0x5, 25)),		/* EINT25 */
 	SUNXI_PIN(SUNXI_PINCTRL_PIN_PI14,
 		  SUNXI_FUNCTION(0x0, "gpio_in"),
-- 
1.8.5.2

[PATCH v2 4/4] ARM: dts: sun7i: Add pin muxing options for clock outputs

[Chen-Yu Tsai]

This patch adds the clock output pin options on the A20.
The 2 pins can output a configurable clock to be used by
external modules. This is used on the CubieTruck, to supply
a 32768 Hz low power clock to the onboard Wifi+BT module.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun7i-a20.dtsi | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index f255a49..7b46ce5 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -416,6 +416,20 @@
 				allwinner,drive = <0>;
 				allwinner,pull = <0>;
 			};
+
+			clk_out_a_pins: clk_out_a at 0 {
+				allwinner,pins = "PI12";
+				allwinner,function = "clk_out_a";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			clk_out_b_pins: clk_out_b at 0 {
+				allwinner,pins = "PI13";
+				allwinner,function = "clk_out_b";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
 		};
 
 		timer at 01c20c00 {
-- 
1.8.5.2

[PATCH v2 3/4] pinctrl: sunxi: Add Allwinner A20 clock output pin functions

[Maxime Ripard]

Hi Chen-Yu,

On Mon, Dec 30, 2013 at 11:25:48AM +0800, Chen-Yu Tsai wrote:
> This patch adds the clock output pin functions on the A20.
> The 2 pins can output a configurable clock to be used by
> external modules. This is used on the CubieTruck, to supply
> a 32768 Hz low power clock to the onboard Wifi+BT module.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v2 4/4] ARM: dts: sun7i: Add pin muxing options for clock outputs

[Maxime Ripard]

Hi Chen-Yu,

On Mon, Dec 30, 2013 at 11:25:49AM +0800, Chen-Yu Tsai wrote:
> This patch adds the clock output pin options on the A20.
> The 2 pins can output a configurable clock to be used by
> external modules. This is used on the CubieTruck, to supply
> a 32768 Hz low power clock to the onboard Wifi+BT module.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  arch/arm/boot/dts/sun7i-a20.dtsi | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
> index f255a49..7b46ce5 100644
> --- a/arch/arm/boot/dts/sun7i-a20.dtsi
> +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
> @@ -416,6 +416,20 @@
>  				allwinner,drive = <0>;
>  				allwinner,pull = <0>;
>  			};
> +
> +			clk_out_a_pins: clk_out_a at 0 {
> +				allwinner,pins = "PI12";
> +				allwinner,function = "clk_out_a";
> +				allwinner,drive = <0>;
> +				allwinner,pull = <0>;
> +			};
> +
> +			clk_out_b_pins: clk_out_b at 0 {
> +				allwinner,pins = "PI13";
> +				allwinner,function = "clk_out_b";
> +				allwinner,drive = <0>;
> +				allwinner,pull = <0>;
> +			};

The labels should be clk_out_[ab]_pins_a. That way, if another muxing
pops up for this clock, we will just need to add the new node, without
modifying the one you add just there.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v2 2/4] ARM: dts: sun7i: external clock outputs

[Maxime Ripard]

Hi,

On Mon, Dec 30, 2013 at 11:25:47AM +0800, Chen-Yu Tsai wrote:
> This commit adds the two external clock outputs available on A20 to
> its device tree. A dummy fixed factor clock is also added to serve as
> the first input of the clock outputs, which according to AW's A20 user
> manual, is the 24MHz oscillator divided by 750.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  arch/arm/boot/dts/sun7i-a20.dtsi | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
> index 4c25f81..f255a49 100644
> --- a/arch/arm/boot/dts/sun7i-a20.dtsi
> +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
> @@ -302,6 +302,33 @@
>  			clocks = <&osc24M>, <&pll6 2>, <&pll5 1>;
>  			clock-output-names = "mbus";
>  		};
> +
> +		/*
> +		 * Dummy clock used by output clocks
> +		 */
> +		osc24M_32k: osc24M_32k {

the node name should be clk to reflect the function of the device, and
not what instance of it it might be.

You should probably use something like clk at 0, to avoid collisions with
other dummy clocks.

Note that we have pretty much the same problem already for the losc
and osc24M, it would be great if you could do a patch for these too :)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v2 2/4] ARM: dts: sun7i: external clock outputs

[Chen-Yu Tsai]

Hi,

On Mon, Dec 30, 2013 at 11:25 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Hi,
>
> On Mon, Dec 30, 2013 at 11:25:47AM +0800, Chen-Yu Tsai wrote:
>> This commit adds the two external clock outputs available on A20 to
>> its device tree. A dummy fixed factor clock is also added to serve as
>> the first input of the clock outputs, which according to AW's A20 user
>> manual, is the 24MHz oscillator divided by 750.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>  arch/arm/boot/dts/sun7i-a20.dtsi | 27 +++++++++++++++++++++++++++
>>  1 file changed, 27 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
>> index 4c25f81..f255a49 100644
>> --- a/arch/arm/boot/dts/sun7i-a20.dtsi
>> +++ b/arch/arm/boot/dts/sun7i-a20.dtsi
>> @@ -302,6 +302,33 @@
>>                       clocks = <&osc24M>, <&pll6 2>, <&pll5 1>;
>>                       clock-output-names = "mbus";
>>               };
>> +
>> +             /*
>> +              * Dummy clock used by output clocks
>> +              */
>> +             osc24M_32k: osc24M_32k {
>
> the node name should be clk to reflect the function of the device, and
> not what instance of it it might be.
>
> You should probably use something like clk at 0, to avoid collisions with
> other dummy clocks.

No problem. I will fix this and the pin mux set names.

> Note that we have pretty much the same problem already for the losc
> and osc24M, it would be great if you could do a patch for these too :)

I will add a patch before this one, so the numbering won't be confusing,
i.e. @1 appears before @0.

Mind if I add a patch enabling i2c0 on CubieTruck?
I noticed it was missing when I helped Carlo with AXP209 stuff.


Cheers

ChenYu

[PATCH v2 2/4] ARM: dts: sun7i: external clock outputs

[Maxime Ripard]

Hi,

On Tue, Dec 31, 2013 at 10:12:50AM +0800, Chen-Yu Tsai wrote:
> Mind if I add a patch enabling i2c0 on CubieTruck?
> I noticed it was missing when I helped Carlo with AXP209 stuff.

Feel free to submit anything you think is relevant :)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v2 3/4] pinctrl: sunxi: Add Allwinner A20 clock output pin functions

[Linus Walleij]

On Mon, Dec 30, 2013 at 4:25 AM, Chen-Yu Tsai <wens@csie.org> wrote:

> This patch adds the clock output pin functions on the A20.
> The 2 pins can output a configurable clock to be used by
> external modules. This is used on the CubieTruck, to supply
> a 32768 Hz low power clock to the onboard Wifi+BT module.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Patch applied with Maxime's ACK.

Yours,
Linus Walleij