[PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Andrew Lunn]

Extends the driver to get properties from device tree. Also extend the
kirkwood DT support to supply the needed properties.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
 arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
 arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
 drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
 4 files changed, 82 insertions(+), 6 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
index b891ee2..89ef899 100644
--- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
@@ -1,4 +1,4 @@
-* I2C
+* Marvell MMP I2C controller
 
 Required properties :
 
@@ -32,3 +32,36 @@ Examples:
 		interrupts = <58>;
 	};
 
+* Marvell MV64XXX I2C controller
+
+Required properties :
+
+ - reg         : Offset and length of the register set for the device
+ - compatible  : should be "marvell,mv64xxx-i2c"
+ - interrupts  : the interrupt number
+ - frequency-m : m factor in baud rate calculation
+
+Recommended properties :
+
+ - frequency-n : n factor in baud rate calculation
+ - timeout-ms  : How long to wait for a transaction to complete
+
+Baud Rate:
+
+The baud rate is calculated thus:
+
+Fscl =          Ftclk
+       ------------------------------------------
+                                (frequency-n + 1)
+       10 *(frequency-m + 1) * 2
+
+Examples:
+
+	i2c@11000 {
+		compatible = "marvell,mv64xxx-i2c";
+		reg = <0x11000 0x20>;
+		interrupts = <29>;
+		frequency-m = <4>;
+		frequency-n = <4>;
+		timeout-ms = <1000>;
+	};
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
index 7d282ab..3091c01 100644
--- a/arch/arm/boot/dts/kirkwood.dtsi
+++ b/arch/arm/boot/dts/kirkwood.dtsi
@@ -63,5 +63,18 @@
 			/* set partition map and/or chip-delay in board dts */
 			status = "disabled";
 		};
+
+		i2c@11000 {
+			compatible = "marvell,mv64xxx-i2c";
+			reg = <0x11000 0x20>;
+			interrupt = <29>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			interrupts = <29>;
+			frequency-m = <8>;
+			frequency-n = <3>;
+			timeout-ms = <1000>;
+			status = "disable";
+		};
 	};
 };
diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index 0942139..5aa025d 100644
--- a/arch/arm/mach-kirkwood/board-dt.c
+++ b/arch/arm/mach-kirkwood/board-dt.c
@@ -28,6 +28,8 @@ static struct of_device_id kirkwood_dt_match_table[] __initdata = {
 
 struct of_dev_auxdata kirkwood_auxdata_lookup[] __initdata = {
 	OF_DEV_AUXDATA("marvell,orion-spi", 0xf1010600, "orion_spi.0", NULL),
+	OF_DEV_AUXDATA("marvell,mv64xxx-i2c", 0xf1011000, "mv64xxx_i2c.0",
+		       NULL),
 	{},
 };
 
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 4f44a33..2146984 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -18,6 +18,9 @@
 #include <linux/mv643xx_i2c.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_i2c.h>
 
 /* Register defines */
 #define	MV64XXX_I2C_REG_SLAVE_ADDR			0x00
@@ -528,7 +531,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
 	int	rc;
 
-	if ((pd->id != 0) || !pdata)
+	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
 		return -ENODEV;
 
 	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
@@ -546,19 +549,35 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 	init_waitqueue_head(&drv_data->waitq);
 	spin_lock_init(&drv_data->lock);
 
-	drv_data->freq_m = pdata->freq_m;
-	drv_data->freq_n = pdata->freq_n;
-	drv_data->irq = platform_get_irq(pd, 0);
+	if (pd->dev.of_node) {
+		of_property_read_u32(pd->dev.of_node, "frequency-m",
+				     &drv_data->freq_m);
+		of_property_read_u32(pd->dev.of_node, "frequency-n",
+				     &drv_data->freq_n);
+		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
+	} else {
+		drv_data->freq_m = pdata->freq_m;
+		drv_data->freq_n = pdata->freq_n;
+		drv_data->irq = platform_get_irq(pd, 0);
+	}
+
 	if (drv_data->irq < 0) {
 		rc = -ENXIO;
 		goto exit_unmap_regs;
 	}
+
 	drv_data->adapter.dev.parent = &pd->dev;
 	drv_data->adapter.algo = &mv64xxx_i2c_algo;
 	drv_data->adapter.owner = THIS_MODULE;
 	drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-	drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
+	if (pd->dev.of_node)
+		drv_data->adapter.timeout = msecs_to_jiffies(
+			of_property_read_u32(pd->dev.of_node, "timeout-ms",
+					     &drv_data->freq_n));
+	else
+		drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
 	drv_data->adapter.nr = pd->id;
+	drv_data->adapter.dev.of_node = pd->dev.of_node;
 	platform_set_drvdata(pd, drv_data);
 	i2c_set_adapdata(&drv_data->adapter, drv_data);
 
@@ -577,6 +596,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 		goto exit_free_irq;
 	}
 
+	of_i2c_register_devices(&drv_data->adapter);
+
 	return 0;
 
 	exit_free_irq:
@@ -602,12 +623,19 @@ mv64xxx_i2c_remove(struct platform_device *dev)
 	return rc;
 }
 
+static const struct of_device_id mv64xxx_i2c_of_match_table[] __devinitdata = {
+	{ .compatible = "marvell,mv64xxx-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
+
 static struct platform_driver mv64xxx_i2c_driver = {
 	.probe	= mv64xxx_i2c_probe,
 	.remove	= __devexit_p(mv64xxx_i2c_remove),
 	.driver	= {
 		.owner	= THIS_MODULE,
 		.name	= MV64XXX_I2C_CTLR_NAME,
+		.of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
 	},
 };
 
-- 
1.7.10

Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Jason Cooper]

On Sun, Jun 10, 2012 at 12:31:59PM +0200, Andrew Lunn wrote:
> Extends the driver to get properties from device tree. Also extend the
> kirkwood DT support to supply the needed properties.
> 
> Signed-off-by: Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
>  arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
>  arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
>  drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
>  4 files changed, 82 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> index b891ee2..89ef899 100644
> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> @@ -1,4 +1,4 @@
> -* I2C
> +* Marvell MMP I2C controller
>  
>  Required properties :
>  
> @@ -32,3 +32,36 @@ Examples:
>  		interrupts = <58>;
>  	};
>  
> +* Marvell MV64XXX I2C controller
> +
> +Required properties :
> +
> + - reg         : Offset and length of the register set for the device
> + - compatible  : should be "marvell,mv64xxx-i2c"
> + - interrupts  : the interrupt number
> + - frequency-m : m factor in baud rate calculation
> +
> +Recommended properties :
> +
> + - frequency-n : n factor in baud rate calculation
> + - timeout-ms  : How long to wait for a transaction to complete
> +
> +Baud Rate:
> +
> +The baud rate is calculated thus:
> +
> +Fscl =          Ftclk
> +       ------------------------------------------
> +                                (frequency-n + 1)
> +       10 *(frequency-m + 1) * 2
> +
> +Examples:
> +
> +	i2c@11000 {
> +		compatible = "marvell,mv64xxx-i2c";
> +		reg = <0x11000 0x20>;
> +		interrupts = <29>;
> +		frequency-m = <4>;
> +		frequency-n = <4>;
> +		timeout-ms = <1000>;
> +	};
> diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
> index 7d282ab..3091c01 100644
> --- a/arch/arm/boot/dts/kirkwood.dtsi
> +++ b/arch/arm/boot/dts/kirkwood.dtsi
> @@ -63,5 +63,18 @@
>  			/* set partition map and/or chip-delay in board dts */
>  			status = "disabled";
>  		};
> +
> +		i2c@11000 {
> +			compatible = "marvell,mv64xxx-i2c";
> +			reg = <0x11000 0x20>;
> +			interrupt = <29>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			interrupts = <29>;
> +			frequency-m = <8>;
> +			frequency-n = <3>;
> +			timeout-ms = <1000>;
> +			status = "disable";
> +		};
>  	};
>  };
> diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
> index 0942139..5aa025d 100644
> --- a/arch/arm/mach-kirkwood/board-dt.c
> +++ b/arch/arm/mach-kirkwood/board-dt.c
> @@ -28,6 +28,8 @@ static struct of_device_id kirkwood_dt_match_table[] __initdata = {
>  
>  struct of_dev_auxdata kirkwood_auxdata_lookup[] __initdata = {
>  	OF_DEV_AUXDATA("marvell,orion-spi", 0xf1010600, "orion_spi.0", NULL),
> +	OF_DEV_AUXDATA("marvell,mv64xxx-i2c", 0xf1011000, "mv64xxx_i2c.0",
> +		       NULL),

Same comment as before regarding magic register addresses...

thx,

Jason.

>  	{},
>  };
>  
> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> index 4f44a33..2146984 100644
> --- a/drivers/i2c/busses/i2c-mv64xxx.c
> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> @@ -18,6 +18,9 @@
>  #include <linux/mv643xx_i2c.h>
>  #include <linux/platform_device.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_i2c.h>
>  
>  /* Register defines */
>  #define	MV64XXX_I2C_REG_SLAVE_ADDR			0x00
> @@ -528,7 +531,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  	struct mv64xxx_i2c_pdata	*pdata = pd->dev.platform_data;
>  	int	rc;
>  
> -	if ((pd->id != 0) || !pdata)
> +	if ((!pdata && !pd->dev.of_node) || (pdata && (pd->id != 0)))
>  		return -ENODEV;
>  
>  	drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
> @@ -546,19 +549,35 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  	init_waitqueue_head(&drv_data->waitq);
>  	spin_lock_init(&drv_data->lock);
>  
> -	drv_data->freq_m = pdata->freq_m;
> -	drv_data->freq_n = pdata->freq_n;
> -	drv_data->irq = platform_get_irq(pd, 0);
> +	if (pd->dev.of_node) {
> +		of_property_read_u32(pd->dev.of_node, "frequency-m",
> +				     &drv_data->freq_m);
> +		of_property_read_u32(pd->dev.of_node, "frequency-n",
> +				     &drv_data->freq_n);
> +		drv_data->irq = irq_of_parse_and_map(pd->dev.of_node, 0);
> +	} else {
> +		drv_data->freq_m = pdata->freq_m;
> +		drv_data->freq_n = pdata->freq_n;
> +		drv_data->irq = platform_get_irq(pd, 0);
> +	}
> +
>  	if (drv_data->irq < 0) {
>  		rc = -ENXIO;
>  		goto exit_unmap_regs;
>  	}
> +
>  	drv_data->adapter.dev.parent = &pd->dev;
>  	drv_data->adapter.algo = &mv64xxx_i2c_algo;
>  	drv_data->adapter.owner = THIS_MODULE;
>  	drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> -	drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
> +	if (pd->dev.of_node)
> +		drv_data->adapter.timeout = msecs_to_jiffies(
> +			of_property_read_u32(pd->dev.of_node, "timeout-ms",
> +					     &drv_data->freq_n));
> +	else
> +		drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
>  	drv_data->adapter.nr = pd->id;
> +	drv_data->adapter.dev.of_node = pd->dev.of_node;
>  	platform_set_drvdata(pd, drv_data);
>  	i2c_set_adapdata(&drv_data->adapter, drv_data);
>  
> @@ -577,6 +596,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>  		goto exit_free_irq;
>  	}
>  
> +	of_i2c_register_devices(&drv_data->adapter);
> +
>  	return 0;
>  
>  	exit_free_irq:
> @@ -602,12 +623,19 @@ mv64xxx_i2c_remove(struct platform_device *dev)
>  	return rc;
>  }
>  
> +static const struct of_device_id mv64xxx_i2c_of_match_table[] __devinitdata = {
> +	{ .compatible = "marvell,mv64xxx-i2c", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
> +
>  static struct platform_driver mv64xxx_i2c_driver = {
>  	.probe	= mv64xxx_i2c_probe,
>  	.remove	= __devexit_p(mv64xxx_i2c_remove),
>  	.driver	= {
>  		.owner	= THIS_MODULE,
>  		.name	= MV64XXX_I2C_CTLR_NAME,
> +		.of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
>  	},
>  };
>  
> -- 
> 1.7.10
> 

Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Ben Dooks]

On 10/06/12 11:31, Andrew Lunn wrote:
> Extends the driver to get properties from device tree. Also extend the
> kirkwood DT support to supply the needed properties.
>
> Signed-off-by: Andrew Lunn<andrew-g2DYL2Zd6BY@public.gmane.org>
> ---
>   Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
>   arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
>   arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
>   drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
>   4 files changed, 82 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> index b891ee2..89ef899 100644
> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> @@ -1,4 +1,4 @@
> -* I2C
> +* Marvell MMP I2C controller
>
>   Required properties :
>
> @@ -32,3 +32,36 @@ Examples:
>   		interrupts =<58>;
>   	};
>
> +* Marvell MV64XXX I2C controller
> +
> +Required properties :
> +
> + - reg         : Offset and length of the register set for the device
> + - compatible  : should be "marvell,mv64xxx-i2c"
> + - interrupts  : the interrupt number
> + - frequency-m : m factor in baud rate calculation
> +
> +Recommended properties :
> +
> + - frequency-n : n factor in baud rate calculation
> + - timeout-ms  : How long to wait for a transaction to complete
> +
> +Baud Rate:
> +
> +The baud rate is calculated thus:
> +
> +Fscl =          Ftclk
> +       ------------------------------------------
> +                                (frequency-n + 1)
> +       10 *(frequency-m + 1) * 2
> +
> +Examples:

I'd really rather see this calculated at run-time, given some
systems can quite easily change their clocks.

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Andrew Lunn]

On Tue, Jun 26, 2012 at 03:03:56PM +0100, Ben Dooks wrote:
> On 10/06/12 11:31, Andrew Lunn wrote:
> >Extends the driver to get properties from device tree. Also extend the
> >kirkwood DT support to supply the needed properties.
> >
> >Signed-off-by: Andrew Lunn<andrew-g2DYL2Zd6BY@public.gmane.org>
> >---
> >  Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
> >  arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
> >  arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
> >  drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
> >  4 files changed, 82 insertions(+), 6 deletions(-)
> >
> >diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> >index b891ee2..89ef899 100644
> >--- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> >+++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> >@@ -1,4 +1,4 @@
> >-* I2C
> >+* Marvell MMP I2C controller
> >
> >  Required properties :
> >
> >@@ -32,3 +32,36 @@ Examples:
> >  		interrupts =<58>;
> >  	};
> >
> >+* Marvell MV64XXX I2C controller
> >+
> >+Required properties :
> >+
> >+ - reg         : Offset and length of the register set for the device
> >+ - compatible  : should be "marvell,mv64xxx-i2c"
> >+ - interrupts  : the interrupt number
> >+ - frequency-m : m factor in baud rate calculation
> >+
> >+Recommended properties :
> >+
> >+ - frequency-n : n factor in baud rate calculation
> >+ - timeout-ms  : How long to wait for a transaction to complete
> >+
> >+Baud Rate:
> >+
> >+The baud rate is calculated thus:
> >+
> >+Fscl =          Ftclk
> >+       ------------------------------------------
> >+                                (frequency-n + 1)
> >+       10 *(frequency-m + 1) * 2
> >+
> >+Examples:
> 
> I'd really rather see this calculated at run-time, given some
> systems can quite easily change their clocks.

Hi Ben

Well, none of the Orion systems would make use of this. They all have
fixed clocks. 

Maybe the new Armada XP systems could make use of clock scaling?  

I've no plans to implement this, but please feel free to send
patches...

     Andrew

Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Ben Dooks]

On 26/06/12 15:10, Andrew Lunn wrote:
> On Tue, Jun 26, 2012 at 03:03:56PM +0100, Ben Dooks wrote:
>> On 10/06/12 11:31, Andrew Lunn wrote:
>>> Extends the driver to get properties from device tree. Also extend the
>>> kirkwood DT support to supply the needed properties.
>>>
>>> Signed-off-by: Andrew Lunn<andrew-g2DYL2Zd6BY@public.gmane.org>
>>> ---
>>>   Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
>>>   arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
>>>   arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
>>>   drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
>>>   4 files changed, 82 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
>>> index b891ee2..89ef899 100644
>>> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
>>> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
>>> @@ -1,4 +1,4 @@
>>> -* I2C
>>> +* Marvell MMP I2C controller
>>>
>>>   Required properties :
>>>
>>> @@ -32,3 +32,36 @@ Examples:
>>>   		interrupts =<58>;
>>>   	};
>>>
>>> +* Marvell MV64XXX I2C controller
>>> +
>>> +Required properties :
>>> +
>>> + - reg         : Offset and length of the register set for the device
>>> + - compatible  : should be "marvell,mv64xxx-i2c"
>>> + - interrupts  : the interrupt number
>>> + - frequency-m : m factor in baud rate calculation
>>> +
>>> +Recommended properties :
>>> +
>>> + - frequency-n : n factor in baud rate calculation
>>> + - timeout-ms  : How long to wait for a transaction to complete
>>> +
>>> +Baud Rate:
>>> +
>>> +The baud rate is calculated thus:
>>> +
>>> +Fscl =          Ftclk
>>> +       ------------------------------------------
>>> +                                (frequency-n + 1)
>>> +       10 *(frequency-m + 1) * 2
>>> +
>>> +Examples:
>>
>> I'd really rather see this calculated at run-time, given some
>> systems can quite easily change their clocks.
>
> Hi Ben
>
> Well, none of the Orion systems would make use of this. They all have
> fixed clocks.
>
> Maybe the new Armada XP systems could make use of clock scaling?

A couple of the development boards here have dip-switches to change
the clocks at start-time, and thus having something that does this
would be useful.

PS, for other people's info, this bounces to the i2c list due to the
use of 'xxx' in the title :(

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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Re: [PATCH 7/9] I2C: MV64XXX: Add Device Tree support

[Wolfram Sang]

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On Sun, Jun 10, 2012 at 12:31:59PM +0200, Andrew Lunn wrote:
> Extends the driver to get properties from device tree. Also extend the
> kirkwood DT support to supply the needed properties.
> 
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> ---
>  Documentation/devicetree/bindings/i2c/mrvl-i2c.txt |   35 +++++++++++++++++-
>  arch/arm/boot/dts/kirkwood.dtsi                    |   13 +++++++
>  arch/arm/mach-kirkwood/board-dt.c                  |    2 ++
>  drivers/i2c/busses/i2c-mv64xxx.c                   |   38 +++++++++++++++++---
>  4 files changed, 82 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> index b891ee2..89ef899 100644
> --- a/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> +++ b/Documentation/devicetree/bindings/i2c/mrvl-i2c.txt
> @@ -1,4 +1,4 @@
> -* I2C
> +* Marvell MMP I2C controller
>  
>  Required properties :
>  
> @@ -32,3 +32,36 @@ Examples:
>  		interrupts = <58>;
>  	};
>  
> +* Marvell MV64XXX I2C controller
> +
> +Required properties :
> +
> + - reg         : Offset and length of the register set for the device
> + - compatible  : should be "marvell,mv64xxx-i2c"
> + - interrupts  : the interrupt number
> + - frequency-m : m factor in baud rate calculation
> +
> +Recommended properties :
> +
> + - frequency-n : n factor in baud rate calculation
> + - timeout-ms  : How long to wait for a transaction to complete

The way we define the bus speed for i2c with DT is using "clock-frequency".
You should be able to derive the dividers from that? Adding custom
properties for every driver will hardly be maintainable.

Thanks,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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