[PATCH v3 0/5] clk: sunxi: add A20 external output clock support

[PATCH v3 0/5] clk: sunxi: add A20 external output clock support

[Chen-Yu Tsai]

Hi everyone,

This is v3 of A20 external output clock support patch series,
addressing issues raised by Maxime.

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 v2:

  - #2, #3: Change dummy clock names to clk at N
  - #5: Change pin mux labels to clk_out_[ab]_pins_a

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 (5):
  clk: sunxi: Allwinner A20 output clock support
  ARM: dts: sun7i: Change 32768 Hz oscillator node name to clk at N style
  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                  | 45 +++++++++++++++++-
 drivers/clk/sunxi/clk-sunxi.c                     | 57 +++++++++++++++++++++++
 drivers/pinctrl/pinctrl-sunxi-pins.h              |  2 +
 4 files changed, 104 insertions(+), 1 deletion(-)

-- 
1.8.5.2

[PATCH v3 1/5] 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..0c127cd 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 on A20
 
 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 v3 1/5] clk: sunxi: Allwinner A20 output clock support

[Maxime Ripard]

Hi,

On Wed, Jan 01, 2014 at 10:30:46AM +0800, Chen-Yu Tsai wrote:
> 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>

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 v3 2/5] ARM: dts: sun7i: Change 32768 Hz oscillator node name to clk@N style

[Chen-Yu Tsai]

Device tree naming conventions state that node names should match
the nodes function. Change external low speed oscillator node name
to match.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---

This patch only changes osc32k in sun7i DT, for proper numbering
of the dummy clocks. osc24M does not support clock-output-names
yet, nor do the other clocks left. I'd like to do thses in another
series, adding support in the clock driver, and fixing up all sunxi
DTs.

 arch/arm/boot/dts/sun7i-a20.dtsi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 4c25f81..c0fb390 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -53,10 +53,11 @@
 			clock-frequency = <24000000>;
 		};
 
-		osc32k: osc32k {
+		osc32k: clk at 0 {
 			#clock-cells = <0>;
 			compatible = "fixed-clock";
 			clock-frequency = <32768>;
+			clock-output-names = "osc32k";
 		};
 
 		pll1: pll1 at 01c20000 {
-- 
1.8.5.2

[PATCH v3 2/5] ARM: dts: sun7i: Change 32768 Hz oscillator node name to clk@N style

[Maxime Ripard]

On Wed, Jan 01, 2014 at 10:30:47AM +0800, Chen-Yu Tsai wrote:
> Device tree naming conventions state that node names should match
> the nodes function. Change external low speed oscillator node name
> to match.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Applied, thanks!

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v3 3/5] 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 | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index c0fb390..e192c99 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -303,6 +303,34 @@
 			clocks = <&osc24M>, <&pll6 2>, <&pll5 1>;
 			clock-output-names = "mbus";
 		};
+
+		/*
+		 * Dummy clock used by output clocks
+		 */
+		osc24M_32k: clk at 1 {
+			#clock-cells = <0>;
+			compatible = "fixed-factor-clock";
+			clock-div = <750>;
+			clock-mult = <1>;
+			clocks = <&osc24M>;
+			clock-output-names = "osc24M_32k";
+		};
+
+		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 v3 3/5] ARM: dts: sun7i: external clock outputs

[Maxime Ripard]

Hi,

On Wed, Jan 01, 2014 at 10:30:48AM +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>

I'm ok with this patch, but I'll let Emilio and Mike give their
opinion on the driver before merging it.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v3 3/5] ARM: dts: sun7i: external clock outputs

[Chen-Yu Tsai]

Hi,

On Thu, Jan 2, 2014 at 7:10 AM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Hi,
>
> On Wed, Jan 01, 2014 at 10:30:48AM +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>
>
> I'm ok with this patch, but I'll let Emilio and Mike give their
> opinion on the driver before merging it.

The driver has not changed since v1.
Mike merged it via Emilio's pull request.

Or are you referring to the DT part?


Cheers,
ChenYu

[PATCH v3 3/5] ARM: dts: sun7i: external clock outputs

[Maxime Ripard]

On Thu, Jan 02, 2014 at 10:41:23AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Thu, Jan 2, 2014 at 7:10 AM, Maxime Ripard
> > On Wed, Jan 01, 2014 at 10:30:48AM +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>
> >
> > I'm ok with this patch, but I'll let Emilio and Mike give their
> > opinion on the driver before merging it.
> 
> The driver has not changed since v1.
> Mike merged it via Emilio's pull request.

Ah, right, I forgot about this.

I just merged this patch as well.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH v3 4/5] 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>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 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 v3 5/5] 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 e192c99..0062811 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -418,6 +418,20 @@
 				allwinner,drive = <0>;
 				allwinner,pull = <0>;
 			};
+
+			clk_out_a_pins_a: clk_out_a at 0 {
+				allwinner,pins = "PI12";
+				allwinner,function = "clk_out_a";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			clk_out_b_pins_a: 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 v3 5/5] ARM: dts: sun7i: Add pin muxing options for clock outputs

[Maxime Ripard]

Hi Chen-Yu,

On Wed, Jan 01, 2014 at 10:30:50AM +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>

Applied to sunxi/dt-for-3.14.

Thanks!
Maxime

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