RE: [PATCH V2 6/8] usb: musb: Offmode fix for idle path

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 Hi,

>-----Original Message-----
>From: Cousson, Benoit 
>Sent: Monday, August 09, 2010 6:31 PM
>To: Kalliguddi, Hema
>Cc: linux-usb@xxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx; 
>Mankad, Maulik Ojas; Felipe Balbi; Tony Lindgren; Kevin Hilman
>Subject: Re: [PATCH V2 6/8] usb: musb: Offmode fix for idle path
>
>On 8/6/2010 7:27 PM, Kalliguddi, Hema wrote:
>> From: Hema HK<hemahk@xxxxxx>
>>
>> With OMAP core-off support musb was not functional as 
>context was getting
>> lost after wakeup from core-off. And also musb was blocking 
>the core-off
>> after loading the gadget driver even with no cable connected 
>sometimes.
>>
>> Added the conext save/restore api in the platform layer which will
>> be called in the idle and wakeup path.
>>
>> Changed the usb sysconfig settings as per the usbotg functional spec.
>> When the device is not active, configure to force idle and 
>force standby mode.
>> When it is being used, configure in smart standby and smart 
>idle mode.
>> So while attempting to coreoff the usb is configured to 
>force standby and
>> force idle mode, after wakeup configured in smart idle and 
>smart standby.
>
>Is this valid for OMAP3 and OMAP4? I checked quickly the OMAP4 
>TRM vB in 
>the USB_OTG chapter related to PM (23.13.4.2 Power-Management), and I 
>cannot find any note regarding that specific programming model.
>Could give us reference to the documentation that contains the details 
>about that?
>
>Benoit
>

This is valid for both OMAP3 and OMAP4. You can find this in 24.1.5.4 section
With different modes. When not used with any application the mode has to be programmed 
is force idle and force standby. What I observed is that without this USB was 
blocking the coreoff.

http://focus.ti.com/pdfs/wtbu/SWPU223D_Final_EPDF_06_07_2010.pdf 

Regards,
Hema
>>
>> Signed-off-by: Hema HK<hemahk@xxxxxx>
>> Signed-off-by: Maulik Mankad<x0082077@xxxxxx>
>>
>> Cc: Felipe Balbi<felipe.balbi@xxxxxxxxx>
>> Cc: Tony Lindgren<tony@xxxxxxxxxxx>
>> Cc: Kevin Hilman<khilman@xxxxxxxxxxxxxxxxxxx>
>> ---
>>
>>   arch/arm/mach-omap2/pm34xx.c          |    4 ++
>>   arch/arm/mach-omap2/usb-musb.c        |   21 ++++++++++++++
>>   arch/arm/plat-omap/include/plat/usb.h |    2 +
>>   drivers/usb/musb/musb_core.c          |   11 -------
>>   drivers/usb/musb/omap2430.c           |   48 
>+++++++++++++++++++++++++++++++---
>>   5 files changed, 71 insertions(+), 15 deletions(-)
>>
>> Index: linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
>> ===================================================================
>> --- linux-omap-pm.orig/arch/arm/mach-omap2/pm34xx.c	
>2010-08-06 09:23:01.153862710 -0400
>> +++ linux-omap-pm/arch/arm/mach-omap2/pm34xx.c	
>2010-08-06 10:44:06.393863125 -0400
>> @@ -39,6 +39,7 @@
>>   #include<plat/gpmc.h>
>>   #include<plat/dma.h>
>>   #include<plat/dmtimer.h>
>> +#include<plat/usb.h>
>>
>>   #include<asm/tlbflush.h>
>>
>> @@ -416,6 +417,8 @@
>>   		if (core_next_state == PWRDM_POWER_OFF) {
>>   			omap3_core_save_context();
>>   			omap3_prcm_save_context();
>> +			/* Save MUSB context */
>> +			musb_context_save_restore(1);
>>   		}
>>   	}
>>
>> @@ -458,6 +461,8 @@
>>   			omap3_prcm_restore_context();
>>   			omap3_sram_restore_context();
>>   			omap2_sms_restore_context();
>> +			/* restore MUSB context */
>> +			musb_context_save_restore(0);
>>   		}
>>   		omap_uart_resume_idle(0);
>>   		omap_uart_resume_idle(1);
>> Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
>> ===================================================================
>> --- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c	
>2010-08-06 09:24:23.690112596 -0400
>> +++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c	
>2010-08-06 10:44:06.385862697 -0400
>> @@ -120,6 +120,27 @@
>>   	}
>>   }
>>
>> +void musb_context_save_restore(int save)
>> +{
>> +	struct omap_hwmod *oh = omap_hwmod_lookup("usb_otg_hs");
>> +	struct omap_device *od = oh->od;
>> +	struct platform_device *pdev =&od->pdev;
>> +	struct device *dev =&pdev->dev;
>> +	struct device_driver *drv = dev->driver;
>> +
>> +	if (drv) {
>> +		struct musb_hdrc_platform_data *pdata = 
>dev->platform_data;
>> +		const struct dev_pm_ops *pm = drv->pm;
>> +		if (!pdata->is_usb_active(dev)) {
>> +
>> +			if (save)
>> +				pm->suspend(dev);
>> +			else
>> +				pm->resume_noirq(dev);
>> +		}
>> +	}
>> +}
>> +
>>   #else
>>   void __init usb_musb_init(struct omap_musb_board_data *board_data)
>>   {
>> Index: linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
>> ===================================================================
>> --- linux-omap-pm.orig/arch/arm/plat-omap/include/plat/usb.h	
>2010-08-06 09:23:01.137862514 -0400
>> +++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h	
>2010-08-06 10:44:06.381864367 -0400
>> @@ -79,6 +79,8 @@
>>
>>   extern void usb_ohci_init(const struct 
>ohci_hcd_omap_platform_data *pdata);
>>
>> +/* For saving and restoring the musb context during off/wakeup*/
>> +extern void musb_context_save_restore(int save);
>>   #endif
>>
>>
>> Index: linux-omap-pm/drivers/usb/musb/musb_core.c
>> ===================================================================
>> --- linux-omap-pm.orig/drivers/usb/musb/musb_core.c	
>2010-08-06 09:24:21.069863329 -0400
>> +++ linux-omap-pm/drivers/usb/musb/musb_core.c	
>2010-08-06 10:44:06.369863527 -0400
>> @@ -2427,11 +2427,6 @@
>>   	}
>>
>>   	musb_save_context(musb);
>> -
>> -	if (musb->set_clock)
>> -		musb->set_clock(musb->clock, 0);
>> -	else
>> -		clk_disable(musb->clock);
>>   	spin_unlock_irqrestore(&musb->lock, flags);
>>   	return 0;
>>   }
>> @@ -2443,12 +2438,6 @@
>>
>>   	if (!musb->clock)
>>   		return 0;
>> -
>> -	if (musb->set_clock)
>> -		musb->set_clock(musb->clock, 1);
>> -	else
>> -		clk_enable(musb->clock);
>> -
>>   	musb_restore_context(musb);
>>
>>   	/* for static cmos like DaVinci, register values were preserved
>> Index: linux-omap-pm/drivers/usb/musb/omap2430.c
>> ===================================================================
>> --- linux-omap-pm.orig/drivers/usb/musb/omap2430.c	
>2010-08-06 09:24:21.069863329 -0400
>> +++ linux-omap-pm/drivers/usb/musb/omap2430.c	
>2010-08-06 10:44:30.093914217 -0400
>> @@ -189,6 +189,19 @@
>>   	return 0;
>>   }
>>
>> +int is_musb_active(struct device *dev)
>> +{
>> +	struct musb *musb;
>> +
>> +#ifdef CONFIG_USB_MUSB_HDRC_HCD
>> +	/* usbcore insists dev->driver_data is a "struct hcd *" */
>> +	musb = hcd_to_musb(dev_get_drvdata(dev));
>> +#else
>> +	musb = dev_get_drvdata(dev);
>> +#endif
>> +	return musb->is_active;
>> +}
>> +
>>   int __init musb_platform_init(struct musb *musb)
>>   {
>>   	u32 l;
>> @@ -250,6 +263,7 @@
>>   	if (is_host_enabled(musb))
>>   		musb->board_set_vbus = omap_set_vbus;
>>
>> +	plat->is_usb_active = is_musb_active;
>>   	setup_timer(&musb_idle_timer, musb_do_idle, (unsigned 
>long) musb);
>>
>>   	return 0;
>> @@ -259,15 +273,42 @@
>>   void musb_platform_save_context(struct musb *musb,
>>   		struct musb_context_registers *musb_context)
>>   {
>> -	musb_context->otg_sysconfig = musb_readl(musb->mregs, 
>OTG_SYSCONFIG);
>> -	musb_context->otg_forcestandby = 
>musb_readl(musb->mregs, OTG_FORCESTDBY);
>> +	/*
>> +	 * As per the omap-usbotg specification, configure it 
>to forced standby
>> +	 * and  force idle mode when no activity on usb.
>> +	 */
>> +	void __iomem *musb_base = musb->mregs;
>> +
>> +	musb_writel(musb_base, OTG_FORCESTDBY, 0);
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +				OTG_SYSCONFIG)&  ~(NOSTDBY | 
>SMARTSTDBY));
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +					OTG_SYSCONFIG)&  ~(AUTOIDLE));
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +				OTG_SYSCONFIG)&  ~(NOIDLE | SMARTIDLE));
>> +
>> +	musb_writel(musb_base, OTG_FORCESTDBY, 1);
>>   }
>>
>>   void musb_platform_restore_context(struct musb *musb,
>>   		struct musb_context_registers *musb_context)
>>   {
>> -	musb_writel(musb->mregs, OTG_SYSCONFIG, 
>musb_context->otg_sysconfig);
>> -	musb_writel(musb->mregs, OTG_FORCESTDBY, 
>musb_context->otg_forcestandby);
>> +	/*
>> +	 * As per the omap-usbotg specification, configure it 
>smart standby
>> +	 * and smart idle during operation.
>> +	 */
>> +	void __iomem *musb_base = musb->mregs;
>> +
>> +	musb_writel(musb_base, OTG_FORCESTDBY, 0);
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +				OTG_SYSCONFIG) | (SMARTSTDBY));
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +				OTG_SYSCONFIG) | (SMARTIDLE));
>>   }
>>   #endif
>>
>> Index: linux-omap-pm/include/linux/usb/musb.h
>> ===================================================================
>> --- linux-omap-pm.orig/include/linux/usb/musb.h	
>2010-08-06 09:23:01.161864151 -0400
>> +++ linux-omap-pm/include/linux/usb/musb.h	2010-08-06 
>10:44:06.401862567 -0400
>> @@ -126,6 +126,9 @@
>>
>>   	/* Architecture specific board data	*/
>>   	void		*board_data;
>> +
>> +	/* check usb device active state*/
>> +	int		(*is_usb_active)(struct device *dev);
>>   };
>>
>>
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