[PATCH 0/5] ARM: sun6i: Add support for the A31 I2C controller

[PATCH 0/5] ARM: sun6i: Add support for the A31 I2C controller

[Maxime Ripard]

Hi everyone,

This patchset adds support the A31 i2c controller. This is mostly the
same controller as the one found in the other Allwinner SoCs, except
for the interrupts acking.

On the other SoCs using this driver, the interrupts are acked by
clearing the INT_FLAG bit in the control register, while on the A31,
the interrupt is acked by writing that bit into the control register.

The other difference is that the I2C IP is maintained in reset by a
reset controller, so we're adding optionnal support for the reset
framework in the driver to deassert the device from reset.

Thanks!
Maxime

Maxime Ripard (5):
  i2c: mv64xxx: Add reset deassert call
  i2c: mv64xxx: Add support for the Allwinner A31 I2C driver
  ARM: sun6i: Enable the I2C controllers
  ARM: sun6i: Enable the I2C muxing options
  ARM: sun6i: colombus: Enable the I2C controllers

 .../devicetree/bindings/i2c/i2c-mv64xxx.txt        |  1 +
 arch/arm/boot/dts/sun6i-a31-colombus.dts           | 18 +++++++
 arch/arm/boot/dts/sun6i-a31.dtsi                   | 61 ++++++++++++++++++++++
 drivers/i2c/busses/Kconfig                         |  1 +
 drivers/i2c/busses/i2c-mv64xxx.c                   | 16 ++++++
 5 files changed, 97 insertions(+)

-- 
1.8.4.2

[PATCH 1/5] i2c: mv64xxx: Add reset deassert call

[Maxime Ripard]

The Allwinner A31 SoC using that IP has a reset controller maintaining
it reset unless told otherwise.

Add some optional reset support to the driver.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 1 +
 drivers/i2c/busses/Kconfig                            | 1 +
 drivers/i2c/busses/i2c-mv64xxx.c                      | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
index 82e8f6f..603003a 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
@@ -12,6 +12,7 @@ Optional properties :
 
  - clock-frequency : Desired I2C bus clock frequency in Hz. If not set the
 default frequency is 100kHz
+ - resets          : phandle to the parent reset controller
 
 Examples:
 
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 3b26129..69aa599 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -528,6 +528,7 @@ config I2C_MPC
 config I2C_MV64XXX
 	tristate "Marvell mv64xxx I2C Controller"
 	depends on (MV64X60 || PLAT_ORION || ARCH_SUNXI)
+	select RESET_CONTROLLER
 	help
 	  If you say yes to this option, support will be included for the
 	  built-in I2C interface on the Marvell 64xxx line of host bridges.
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 8be7e42..d4e2f32 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -17,6 +17,7 @@
 #include <linux/interrupt.h>
 #include <linux/mv643xx_i2c.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -743,6 +744,7 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 #else
 	const struct of_device_id *device;
 	struct device_node *np = dev->of_node;
+	struct reset_control *rstc;
 	u32 bus_freq, tclk;
 	int rc = 0;
 
@@ -763,6 +765,10 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 	}
 	drv_data->irq = irq_of_parse_and_map(np, 0);
 
+	rstc = devm_reset_control_get(dev, NULL);
+	if (!IS_ERR(rstc))
+		reset_control_deassert(rstc);
+
 	/* Its not yet defined how timeouts will be specified in device tree.
 	 * So hard code the value to 1 second.
 	 */
-- 
1.8.4.2

Re: [PATCH 1/5] i2c: mv64xxx: Add reset deassert call

[Chen-Yu Tsai]

Hi,

On Fri, Jan 10, 2014 at 1:19 AM, Maxime Ripard
<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> wrote:
> The Allwinner A31 SoC using that IP has a reset controller maintaining
> it reset unless told otherwise.
>
> Add some optional reset support to the driver.
>
> Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 1 +
>  drivers/i2c/busses/Kconfig                            | 1 +
>  drivers/i2c/busses/i2c-mv64xxx.c                      | 6 ++++++
>  3 files changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> index 82e8f6f..603003a 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> @@ -12,6 +12,7 @@ Optional properties :
>
>   - clock-frequency : Desired I2C bus clock frequency in Hz. If not set the
>  default frequency is 100kHz
> + - resets          : phandle to the parent reset controller
>
>  Examples:
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 3b26129..69aa599 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -528,6 +528,7 @@ config I2C_MPC
>  config I2C_MV64XXX
>         tristate "Marvell mv64xxx I2C Controller"
>         depends on (MV64X60 || PLAT_ORION || ARCH_SUNXI)
> +       select RESET_CONTROLLER
>         help
>           If you say yes to this option, support will be included for the
>           built-in I2C interface on the Marvell 64xxx line of host bridges.
> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> index 8be7e42..d4e2f32 100644
> --- a/drivers/i2c/busses/i2c-mv64xxx.c
> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> @@ -17,6 +17,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/mv643xx_i2c.h>
>  #include <linux/platform_device.h>
> +#include <linux/reset.h>
>  #include <linux/io.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> @@ -743,6 +744,7 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
>  #else
>         const struct of_device_id *device;
>         struct device_node *np = dev->of_node;
> +       struct reset_control *rstc;
>         u32 bus_freq, tclk;
>         int rc = 0;
>
> @@ -763,6 +765,10 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
>         }
>         drv_data->irq = irq_of_parse_and_map(np, 0);
>
> +       rstc = devm_reset_control_get(dev, NULL);
> +       if (!IS_ERR(rstc))
> +               reset_control_deassert(rstc);
> +

Do we need to handle -EPROBE_DEFER here?
Also no reset_control_assert() in the exit path?
I'm asking because I have similar code in my stmmac patches.

Thanks

ChenYu

>         /* Its not yet defined how timeouts will be specified in device tree.
>          * So hard code the value to 1 second.
>          */

Re: [PATCH 1/5] i2c: mv64xxx: Add reset deassert call

[Maxime Ripard]

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Hi,

On Fri, Jan 10, 2014 at 01:48:41PM +0800, Chen-Yu Tsai wrote:
> On Fri, Jan 10, 2014 at 1:19 AM, Maxime Ripard
> <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> wrote:
> > The Allwinner A31 SoC using that IP has a reset controller maintaining
> > it reset unless told otherwise.
> >
> > Add some optional reset support to the driver.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> > ---
> >  Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 1 +
> >  drivers/i2c/busses/Kconfig                            | 1 +
> >  drivers/i2c/busses/i2c-mv64xxx.c                      | 6 ++++++
> >  3 files changed, 8 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> > index 82e8f6f..603003a 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
> > @@ -12,6 +12,7 @@ Optional properties :
> >
> >   - clock-frequency : Desired I2C bus clock frequency in Hz. If not set the
> >  default frequency is 100kHz
> > + - resets          : phandle to the parent reset controller
> >
> >  Examples:
> >
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index 3b26129..69aa599 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -528,6 +528,7 @@ config I2C_MPC
> >  config I2C_MV64XXX
> >         tristate "Marvell mv64xxx I2C Controller"
> >         depends on (MV64X60 || PLAT_ORION || ARCH_SUNXI)
> > +       select RESET_CONTROLLER
> >         help
> >           If you say yes to this option, support will be included for the
> >           built-in I2C interface on the Marvell 64xxx line of host bridges.
> > diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> > index 8be7e42..d4e2f32 100644
> > --- a/drivers/i2c/busses/i2c-mv64xxx.c
> > +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> > @@ -17,6 +17,7 @@
> >  #include <linux/interrupt.h>
> >  #include <linux/mv643xx_i2c.h>
> >  #include <linux/platform_device.h>
> > +#include <linux/reset.h>
> >  #include <linux/io.h>
> >  #include <linux/of.h>
> >  #include <linux/of_device.h>
> > @@ -743,6 +744,7 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
> >  #else
> >         const struct of_device_id *device;
> >         struct device_node *np = dev->of_node;
> > +       struct reset_control *rstc;
> >         u32 bus_freq, tclk;
> >         int rc = 0;
> >
> > @@ -763,6 +765,10 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
> >         }
> >         drv_data->irq = irq_of_parse_and_map(np, 0);
> >
> > +       rstc = devm_reset_control_get(dev, NULL);
> > +       if (!IS_ERR(rstc))
> > +               reset_control_deassert(rstc);
> > +
> 
> Do we need to handle -EPROBE_DEFER here?

Hmmm, true.

> Also no reset_control_assert() in the exit path?
> I'm asking because I have similar code in my stmmac patches.

That might be a good idea indeed.

Thanks!
Maxime

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

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[PATCH 2/5] i2c: mv64xxx: Add support for the Allwinner A31 I2C driver

[Maxime Ripard]

The Allwinner A31 I2C controller is almost identical to the one used in the
other Allwinner SoCs, except for the fact that it needs to clear the interrupt
by setting the INT_FLAGS bit in the control register, instead of clearing it.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/i2c/busses/i2c-mv64xxx.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index d4e2f32..a2f6173 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -150,6 +150,7 @@ struct mv64xxx_i2c_data {
 	bool			offload_enabled;
 /* 5us delay in order to avoid repeated start timing violation */
 	bool			errata_delay;
+	bool			irq_clear_inverted;
 };
 
 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
@@ -567,6 +568,11 @@ mv64xxx_i2c_intr(int irq, void *dev_id)
 		status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
 		mv64xxx_i2c_fsm(drv_data, status);
 		mv64xxx_i2c_do_action(drv_data);
+
+		if (drv_data->irq_clear_inverted)
+			writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG,
+			       drv_data->reg_base + drv_data->reg_offsets.control);
+
 		rc = IRQ_HANDLED;
 	}
 	spin_unlock_irqrestore(&drv_data->lock, flags);
@@ -691,6 +697,7 @@ static const struct i2c_algorithm mv64xxx_i2c_algo = {
  */
 static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
 	{ .compatible = "allwinner,sun4i-i2c", .data = &mv64xxx_i2c_regs_sun4i},
+	{ .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i},
 	{ .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
 	{ .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
 	{}
@@ -789,6 +796,9 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 		drv_data->errata_delay = true;
 	}
 
+	if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
+		drv_data->irq_clear_inverted = true;
+
 out:
 	return rc;
 #endif
-- 
1.8.4.2

[PATCH 3/5] ARM: sun6i: Enable the I2C controllers

[Maxime Ripard]

The A31 has 4 I2C controllers that are the same than the one in the
other Allwinner SoCs, except for the fact that they are asserted in
reset by the reset unit.

Add these i2c controllers to the DTSI.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 5256ad9..7dac496 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -312,6 +312,46 @@
 			status = "disabled";
 		};
 
+		i2c0: i2c@01c2ac00 {
+			compatible = "allwinner,sun6i-a31-i2c";
+			reg = <0x01c2ac00 0x400>;
+			interrupts = <0 6 4>;
+			clocks = <&apb2_gates 0>;
+			clock-frequency = <100000>;
+			resets = <&apb2_rst 0>;
+			status = "disabled";
+		};
+
+		i2c1: i2c@01c2b000 {
+			compatible = "allwinner,sun6i-a31-i2c";
+			reg = <0x01c2b000 0x400>;
+			interrupts = <0 7 4>;
+			clocks = <&apb2_gates 1>;
+			clock-frequency = <100000>;
+			resets = <&apb2_rst 1>;
+			status = "disabled";
+		};
+
+		i2c2: i2c@01c2b400 {
+			compatible = "allwinner,sun6i-a31-i2c";
+			reg = <0x01c2b400 0x400>;
+			interrupts = <0 8 4>;
+			clocks = <&apb2_gates 2>;
+			clock-frequency = <100000>;
+			resets = <&apb2_rst 2>;
+			status = "disabled";
+		};
+
+		i2c3: i2c@01c2b800 {
+			compatible = "allwinner,sun6i-a31-i2c";
+			reg = <0x01c2b800 0x400>;
+			interrupts = <0 9 4>;
+			clocks = <&apb2_gates 3>;
+			clock-frequency = <100000>;
+			resets = <&apb2_rst 3>;
+			status = "disabled";
+		};
+
 		gic: interrupt-controller@01c81000 {
 			compatible = "arm,cortex-a7-gic", "arm,cortex-a15-gic";
 			reg = <0x01c81000 0x1000>,
-- 
1.8.4.2

[PATCH 4/5] ARM: sun6i: Enable the I2C muxing options

[Maxime Ripard]

The i2c controllers have a few muxing options on the A31. Enable the
ones found in the A31 Colombus board.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/boot/dts/sun6i-a31.dtsi | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi
index 7dac496..668de00 100644
--- a/arch/arm/boot/dts/sun6i-a31.dtsi
+++ b/arch/arm/boot/dts/sun6i-a31.dtsi
@@ -210,6 +210,27 @@
 				allwinner,drive = <0>;
 				allwinner,pull = <0>;
 			};
+
+			i2c0_pins_a: i2c0@0 {
+				allwinner,pins = "PH14", "PH15";
+				allwinner,function = "i2c0";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c1_pins_a: i2c1@0 {
+				allwinner,pins = "PH16", "PH17";
+				allwinner,function = "i2c1";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			i2c2_pins_a: i2c2@0 {
+				allwinner,pins = "PH18", "PH19";
+				allwinner,function = "i2c2";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
 		};
 
 		ahb1_rst: reset@01c202c0 {
-- 
1.8.4.2

[PATCH 5/5] ARM: sun6i: colombus: Enable the I2C controllers

[Maxime Ripard]

The A31 Colombus board has 3 I2C controllers that should be usable. However,
the first one is not working for some reason on the hardware I have been able
to test it on, while it should really be the same controller. Enable the i2c1
and i2c2 busses, and mark i2c0 as in failure in the DT.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/boot/dts/sun6i-a31-colombus.dts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm/boot/dts/sun6i-a31-colombus.dts b/arch/arm/boot/dts/sun6i-a31-colombus.dts
index e5adae3..3898a7b 100644
--- a/arch/arm/boot/dts/sun6i-a31-colombus.dts
+++ b/arch/arm/boot/dts/sun6i-a31-colombus.dts
@@ -28,5 +28,23 @@
 			pinctrl-0 = <&uart0_pins_a>;
 			status = "okay";
 		};
+
+		i2c0: i2c@01c2ac00 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&i2c0_pins_a>;
+			status = "fail";
+		};
+
+		i2c1: i2c@01c2b000 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&i2c1_pins_a>;
+			status = "okay";
+		};
+
+		i2c2: i2c@01c2b400 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&i2c2_pins_a>;
+			status = "okay";
+		};
 	};
 };
-- 
1.8.4.2