[PATCH v2 3/4] usb: chipidea: ci13xxx-imx: add "dr_mode" property to device tree bindings

Marc Kleine-Budde mkl at pengutronix.de
Fri Jun 29 17:47:03 EST 2012 

Cc'ed Devicetree Discussions

On 06/29/2012 03:43 AM, Richard Zhao wrote:
> On Thu, Jun 28, 2012 at 03:53:48PM +0200, Marc Kleine-Budde wrote:
>> This patch allows the device tree to limit the chipidea to host or
>> peripheral mode only.
>>
>> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
>> ---
>>  .../devicetree/bindings/usb/ci13xxx-imx.txt        |    3 ++
>>  drivers/usb/chipidea/ci13xxx_imx.c                 |    3 ++
>>  drivers/usb/chipidea/core.c                        |   41 +++++++++++++++++---
>>  include/linux/usb/chipidea.h                       |    9 +++++
>>  4 files changed, 50 insertions(+), 6 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
>> index 5a0ad66..67f97f56 100644
>> --- a/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
>> +++ b/Documentation/devicetree/bindings/usb/ci13xxx-imx.txt
>> @@ -4,6 +4,8 @@ Required properties:
>>  - compatible: Should be "fsl,imx27-usb"
>>  - reg: Should contain registers location and length
>>  - interrupts: Should contain controller interrupt
>> +- dr_mode: indicates the working mode for compatible controllers. Can
>> +  be "host", "peripheral", or "otg". Defaults to "otg" if not defined.

> By default, it should be decided by capability registers. Only bad hw
> design needs such settings. So, why not name it as force-xxx? If it's
> not specific to imx, it doesn't needs to has prefix "fsl,".

It's not a bad hardware design if you don't route or enable all ports a
soc offers. In modern socs you cannot enable all ports anyway.

The property isn't prefixed with "fsl,", it's just "dr_mode".

Why not "force-xxx"? I had a look at Documentation/devicetree/bindings/usb:

tegra-usb.txt:
>   - dr_mode : dual role mode. Indicates the working mode for
>    nvidia,tegra20-ehci compatible controllers.  Can be "host", "peripheral",
>    or "otg".  Default to "host" if not defined for backward compatibility.
>       host means this is a host controller
>       peripheral means it is device controller
>       otg means it can operate as either ("on the go")

fsl-usb.txt:
>  - dr_mode : indicates the working mode for "fsl-usb2-dr" compatible
>    controllers.  Can be "host", "peripheral", or "otg".  Default to
>    "host" if not defined for backward compatibility.
> 

So why invent something new, if there seems to be a pattern?

>>  
>>  Optional properties:
>>  - fsl,usbphy: phandler of usb phy that connects to the only one port
>> @@ -14,4 +16,5 @@ usb at 02184000 { /* USB OTG */
>>  	reg = <0x02184000 0x200>;
>>  	interrupts = <0 43 0x04>;
>>  	fsl,usbphy = <&usbphy1>;
>> +	dr_mode= "otg";
>>  };
>> diff --git a/drivers/usb/chipidea/ci13xxx_imx.c b/drivers/usb/chipidea/ci13xxx_imx.c
>> index efae2be..8e926fb 100644
>> --- a/drivers/usb/chipidea/ci13xxx_imx.c
>> +++ b/drivers/usb/chipidea/ci13xxx_imx.c
>> @@ -120,6 +120,9 @@ static int __devinit ci13xxx_imx_probe(struct platform_device *pdev)
>>  		*pdev->dev.dma_mask = DMA_BIT_MASK(32);
>>  		dma_set_coherent_mask(&pdev->dev, *pdev->dev.dma_mask);
>>  	}
>> +
>> +	ci13xxx_get_dr_mode(pdev->dev.of_node, &ci13xxx_imx_platdata);
>> +
>>  	plat_ci = ci13xxx_add_device(&pdev->dev,
>>  				pdev->resource, pdev->num_resources,
>>  				&ci13xxx_imx_platdata);
>> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
>> index 1083585..aa8b1856 100644
>> --- a/drivers/usb/chipidea/core.c
>> +++ b/drivers/usb/chipidea/core.c
>> @@ -63,6 +63,8 @@
>>  #include <linux/kernel.h>
>>  #include <linux/slab.h>
>>  #include <linux/pm_runtime.h>
>> +#include <linux/of.h>
>> +#include <linux/of_platform.h>
>>  #include <linux/usb/ch9.h>
>>  #include <linux/usb/gadget.h>
>>  #include <linux/usb/otg.h>
>> @@ -386,6 +388,23 @@ void ci13xxx_remove_device(struct platform_device *pdev)
>>  }
>>  EXPORT_SYMBOL_GPL(ci13xxx_remove_device);
>>  
>> +void ci13xxx_get_dr_mode(struct device_node *of_node, struct ci13xxx_platform_data *pdata)
>> +{
>> +	const unsigned char *dr_mode;
>> +
>> +	dr_mode = of_get_property(of_node, "dr_mode", NULL);
>> +	if (!dr_mode)
>> +		return;
>> +
>> +	if (!strcmp(dr_mode, "host"))
>> +		pdata->flags |= CI13XXX_DR_MODE_HOST;
>> +	else if (!strcmp(dr_mode, "peripheral"))
>> +		pdata->flags |= CI13XXX_DR_MODE_PERIPHERAL;
>> +	else if (!strcmp(dr_mode, "otg"))
>> +		pdata->flags |= CI13XXX_DR_MODE_OTG;
>> +}
>> +EXPORT_SYMBOL_GPL(ci13xxx_get_dr_mode);

> If you make the property name generic, this function is not specific to
> chipidea. IMHO, the function is simple, if we do it in individual
> drivers, it's ok too.

The property name is generic, it's just "dr_mode", but the function is
chipidea specific, because it's working on the ci13xxx_platform_data.

>> +
>>  static int __devinit ci_hdrc_probe(struct platform_device *pdev)
>>  {
>>  	struct device	*dev = &pdev->dev;
>> @@ -446,13 +465,23 @@ static int __devinit ci_hdrc_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	/* initialize role(s) before the interrupt is requested */
>> -	ret = ci_hdrc_host_init(ci);
>> -	if (ret)
>> -		dev_info(dev, "doesn't support host\n");
>> +	/* default to otg */
>> +	if (!(ci->platdata->flags & CI13XXX_DR_MODE_MASK))
>> +		ci->platdata->flags |= CI13XXX_DR_MODE_OTG;
>> +
>> +	if (ci->platdata->flags &
>> +	    (CI13XXX_DR_MODE_HOST | CI13XXX_DR_MODE_OTG)) {
>> +		ret = ci_hdrc_host_init(ci);
>> +		if (ret)
>> +			dev_info(dev, "doesn't support host\n");
>> +	}
>>  
>> -	ret = ci_hdrc_gadget_init(ci);
>> -	if (ret)
>> -		dev_info(dev, "doesn't support gadget\n");
>> +	if (ci->platdata->flags &
>> +	    (CI13XXX_DR_MODE_PERIPHERAL | CI13XXX_DR_MODE_OTG)) {
>> +		ret = ci_hdrc_gadget_init(ci);
>> +		if (ret)
>> +			dev_info(dev, "doesn't support gadget\n");
>> +	}
>>  
>>  	if (!ci->roles[CI_ROLE_HOST] && !ci->roles[CI_ROLE_GADGET]) {
>>  		dev_err(dev, "no supported roles\n");
>> diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
>> index 544825d..29ad908 100644
>> --- a/include/linux/usb/chipidea.h
>> +++ b/include/linux/usb/chipidea.h
>> @@ -19,6 +19,12 @@ struct ci13xxx_platform_data {
>>  #define CI13XXX_REQUIRE_TRANSCEIVER	BIT(1)
>>  #define CI13XXX_PULLUP_ON_VBUS		BIT(2)
>>  #define CI13XXX_DISABLE_STREAMING	BIT(3)
>> +#define CI13XXX_DR_MODE_HOST		BIT(4)
>> +#define CI13XXX_DR_MODE_PERIPHERAL	BIT(5)
>> +#define CI13XXX_DR_MODE_OTG		BIT(6)
> All we need is CI13XXX_DR_FORCE_HOST and CI13XXX_DR_FORCE_DEVICE.

Okay.

> 
> Thanks
> Richard
>> +#define CI13XXX_DR_MODE_MASK \
>> +	(CI13XXX_DR_MODE_HOST | CI13XXX_DR_MODE_PERIPHERAL | \
>> +	 CI13XXX_DR_MODE_OTG)
>>  
>>  #define CI13XXX_CONTROLLER_RESET_EVENT		0
>>  #define CI13XXX_CONTROLLER_STOPPED_EVENT	1
>> @@ -35,4 +41,7 @@ struct platform_device *ci13xxx_add_device(struct device *dev,
>>  /* Remove ci13xxx device */
>>  void ci13xxx_remove_device(struct platform_device *pdev);
>>  
>> +/* Parse of-tree "dr_mode" property */
>> +void ci13xxx_get_dr_mode(struct device_node *of_node, struct ci13xxx_platform_data *pdata);
>> +
>>  #endif
>> -- 
>> 1.7.10
>>
>>
> 

Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |

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