[PATCH] usb: musb: Offmode fix for idle path

[PATCH] usb: musb: Offmode fix for idle path

[Hema HK]

From: Hema HK  <hemahk@ti.com>

With OMAP coreoff support usb was not functional as context was getting
lost after wakeup from coreoff. And also usb was blocking the coreoff 
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 used, configure in 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.

Since clock used for musb is auto gated, there is no need to specifically
enable/disable the clock. Removed enable/disable clock in suspend resume api.

Signed-off-by: Hema HK <hemahk@ti.com>
Signed-off-by: Maulik Mankad <x0082077@ti.com>

Cc: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
---
Based off : Kevin pm branch.

 arch/arm/mach-omap2/pm34xx.c          |    4 ++++
 arch/arm/mach-omap2/usb-musb.c        |   15 +++++++++++++++
 arch/arm/plat-omap/include/plat/usb.h |    2 ++
 drivers/usb/musb/musb_core.c          |   11 -----------
 drivers/usb/musb/omap2430.c           |   32 ++++++++++++++++++++++++++++----
 5 files changed, 49 insertions(+), 15 deletions(-)

Index: linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
===================================================================
--- linux-omap-pm.orig/arch/arm/mach-omap2/pm34xx.c
+++ linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
@@ -431,6 +431,8 @@ void omap_sram_idle(void)
 		if (core_next_state == PWRDM_POWER_OFF) {
 			omap3_core_save_context();
 			omap3_prcm_save_context();
+			/* Save MUSB context */
+			musb_context_save_restore(1);
 		}
 	}
 
@@ -479,6 +481,8 @@ void omap_sram_idle(void)
 			omap3_prcm_restore_context();
 			omap3_sram_restore_context();
 			omap2_sms_restore_context();
+			/* Restore MUSB context */
+			musb_context_save_restore(0);
 			/*
 			 * Errata 1.164 fix : OTG autoidle can prevent
 			 * sleep
Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
===================================================================
--- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c
+++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
@@ -177,6 +177,21 @@ void __init usb_musb_init(struct omap_mu
 	usb_musb_pm_init();
 }
 
+void musb_context_save_restore(int save)
+{
+	struct device *dev = &musb_device.dev;
+	struct device_driver *drv = dev->driver;
+	if (dev->driver) {
+
+		const struct dev_pm_ops *pm = drv->pm;
+
+		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
+++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
@@ -82,6 +82,8 @@ extern void usb_ohci_init(const struct o
 /* This is needed for OMAP3 errata 1.164: enabled autoidle can prevent sleep */
 extern void usb_musb_disable_autoidle(void);
 
+/* For saving and restoring the musb context during off/wakeup*/
+extern void musb_context_save_restore(int save);
 #endif
 
 void omap_usb_init(struct omap_usb_config *pdata);
Index: linux-omap-pm/drivers/usb/musb/musb_core.c
===================================================================
--- linux-omap-pm.orig/drivers/usb/musb/musb_core.c
+++ linux-omap-pm/drivers/usb/musb/musb_core.c
@@ -2430,11 +2430,6 @@ static int musb_suspend(struct device *d
 	}
 
 	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;
 }
@@ -2446,12 +2441,6 @@ static int musb_resume_noirq(struct devi
 
 	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
+++ linux-omap-pm/drivers/usb/musb/omap2430.c
@@ -257,15 +257,39 @@ int __init musb_platform_init(struct mus
 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 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 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
 

Re: [PATCH] usb: musb: Offmode fix for idle path

[Sergei Shtylyov]

Hello.

Hema HK wrote:

> With OMAP coreoff support usb was not functional as context was getting
> lost after wakeup from coreoff. And also usb was blocking the coreoff 

    USB is an acronym.

> after loading the gadget driver even with no cable connected sometimes.

> Added the conext save/restore api in the platform layer which will

    API is an acronym.

> be called in the idle and wakeup path.

> Changed the usb sysconfig settings as per the usbotg functional spec.

    Do you mean the OTG supplement to USB 2.0 spec. or something else?

> When the device is not used, configure in 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.

> Since clock used for musb is auto gated, there is no need to specifically
> enable/disable the clock. Removed enable/disable clock in suspend resume api.

    I'm not sure it's auto-gated on all platforms...

> Signed-off-by: Hema HK <hemahk@ti.com>
> Signed-off-by: Maulik Mankad <x0082077@ti.com>

> Cc: Felipe Balbi <felipe.balbi@nokia.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Kevin Hilman <khilman@deeprootsystems.com>

> Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
> ===================================================================
> --- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c
> +++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
> @@ -177,6 +177,21 @@ void __init usb_musb_init(struct omap_mu
>  	usb_musb_pm_init();
>  }
>  
> +void musb_context_save_restore(int save)
> +{
> +	struct device *dev = &musb_device.dev;
> +	struct device_driver *drv = dev->driver;

    Need an empty line here.

> +	if (dev->driver) {

   You've just assigned that to 'drv' -- why not use it?

> Index: linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
> ===================================================================
> --- linux-omap-pm.orig/arch/arm/plat-omap/include/plat/usb.h
> +++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
> @@ -82,6 +82,8 @@ extern void usb_ohci_init(const struct o
>  /* This is needed for OMAP3 errata 1.164: enabled autoidle can prevent sleep */
>  extern void usb_musb_disable_autoidle(void);
>  
> +/* For saving and restoring the musb context during off/wakeup*/
> +extern void musb_context_save_restore(int save);
>  #endif
>  
>  void omap_usb_init(struct omap_usb_config *pdata);
> Index: linux-omap-pm/drivers/usb/musb/musb_core.c
> ===================================================================
> --- linux-omap-pm.orig/drivers/usb/musb/musb_core.c
> +++ linux-omap-pm/drivers/usb/musb/musb_core.c
> @@ -2430,11 +2430,6 @@ static int musb_suspend(struct device *d
>  	}
>  
>  	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;
>  }
> @@ -2446,12 +2441,6 @@ static int musb_resume_noirq(struct devi
>  
>  	if (!musb->clock)
>  		return 0;
> -
> -	if (musb->set_clock)
> -		musb->set_clock(musb->clock, 1);
> -	else
> -		clk_enable(musb->clock);
> -

    OK, maybe for OMAP the clock is auto-gated but what about the other platforms?

>  	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
> +++ linux-omap-pm/drivers/usb/musb/omap2430.c
> @@ -257,15 +257,39 @@ int __init musb_platform_init(struct mus
>  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 specification, configure it to forced standby
> +	 * and  force idle mode when no activity on usb.
> +	 */
> +	void __iomem *musb_base = musb->mregs;

    Need an empty line here.

> +	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));

    Parens around AUTOIDLE are not useful.

> +
> +	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 specification, configure it smart standby
> +	 * and smart idle during operation.
> +	 */
> +	void __iomem *musb_base = musb->mregs;

   Need an empty line here.

> +	musb_writel(musb_base, OTG_FORCESTDBY, 0);
> +
> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
> +				OTG_SYSCONFIG) | (SMARTSTDBY));

    Parens around SMARTSTDBY are not useful.

> +
> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
> +					OTG_SYSCONFIG) | (SMARTIDLE));

    Ditto about parens around SMARTIDLE...

WBR, Sergei

RE: [PATCH] usb: musb: Offmode fix for idle path

[Sripathy, Vishwanath]

Hema,

> -----Original Message-----
> From: linux-omap-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-omap-
> owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Kalliguddi, Hema
> Sent: Thursday, July 08, 2010 3:59 PM
> To: linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Cc: Kalliguddi, Hema; Mankad, Maulik Ojas; Felipe Balbi; Tony Lindgren; Kevin Hilman
> Subject: [PATCH] usb: musb: Offmode fix for idle path
> 
> From: Hema HK  <hemahk-l0cyMroinI0@public.gmane.org>
> 
> With OMAP coreoff support usb was not functional as context was getting
> lost after wakeup from coreoff. And also usb was blocking the coreoff
> 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 used, configure in 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.
> 
> Since clock used for musb is auto gated, there is no need to specifically
> enable/disable the clock. Removed enable/disable clock in suspend resume api.
> 
> Signed-off-by: Hema HK <hemahk-l0cyMroinI0@public.gmane.org>
> Signed-off-by: Maulik Mankad <x0082077-l0cyMroinI0@public.gmane.org>
> 
> Cc: Felipe Balbi <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
> Cc: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
> Cc: Kevin Hilman <khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
> ---
> Based off : Kevin pm branch.
> 
>  arch/arm/mach-omap2/pm34xx.c          |    4 ++++
>  arch/arm/mach-omap2/usb-musb.c        |   15 +++++++++++++++
>  arch/arm/plat-omap/include/plat/usb.h |    2 ++
>  drivers/usb/musb/musb_core.c          |   11 -----------
>  drivers/usb/musb/omap2430.c           |   32
> ++++++++++++++++++++++++++++----
>  5 files changed, 49 insertions(+), 15 deletions(-)
> 
> Index: linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
> =====================================================
> ==============
> --- linux-omap-pm.orig/arch/arm/mach-omap2/pm34xx.c
> +++ linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
> @@ -431,6 +431,8 @@ void omap_sram_idle(void)
>  		if (core_next_state == PWRDM_POWER_OFF) {
>  			omap3_core_save_context();
>  			omap3_prcm_save_context();
> +			/* Save MUSB context */
> +			musb_context_save_restore(1);
Do you really need to save and restore USB context in every OS Idle? Can't it be done on a need basis like when USB is connected?
>  		}
>  	}
> 
> @@ -479,6 +481,8 @@ void omap_sram_idle(void)
>  			omap3_prcm_restore_context();
>  			omap3_sram_restore_context();
>  			omap2_sms_restore_context();
> +			/* Restore MUSB context */
> +			musb_context_save_restore(0);
>  			/*
>  			 * Errata 1.164 fix : OTG autoidle can prevent
>  			 * sleep
> Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
> =====================================================
> ==============
> --- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c
> +++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
> @@ -177,6 +177,21 @@ void __init usb_musb_init(struct omap_mu
>  	usb_musb_pm_init();
>  }
> 
> +void musb_context_save_restore(int save)
> +{
> +	struct device *dev = &musb_device.dev;
> +	struct device_driver *drv = dev->driver;
> +	if (dev->driver) {
> +
> +		const struct dev_pm_ops *pm = drv->pm;
> +
> +		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
> +++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
> @@ -82,6 +82,8 @@ extern void usb_ohci_init(const struct o
>  /* This is needed for OMAP3 errata 1.164: enabled autoidle can prevent sleep */
>  extern void usb_musb_disable_autoidle(void);
> 
> +/* For saving and restoring the musb context during off/wakeup*/
> +extern void musb_context_save_restore(int save);
>  #endif
> 
>  void omap_usb_init(struct omap_usb_config *pdata);
> Index: linux-omap-pm/drivers/usb/musb/musb_core.c
> =====================================================
> ==============
> --- linux-omap-pm.orig/drivers/usb/musb/musb_core.c
> +++ linux-omap-pm/drivers/usb/musb/musb_core.c
> @@ -2430,11 +2430,6 @@ static int musb_suspend(struct device *d
>  	}
> 
>  	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;
>  }
> @@ -2446,12 +2441,6 @@ static int musb_resume_noirq(struct devi
> 
>  	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
> +++ linux-omap-pm/drivers/usb/musb/omap2430.c
> @@ -257,15 +257,39 @@ int __init musb_platform_init(struct mus
>  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 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);
>  }

Since this is called from OS Idle, I would suggest to optimize this code so that you will save the context only when currently saved context is different from the already stored one. Otherwise you will end of saving the same context every time unnecessary. 
> 
>  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 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));
>  }
Restore should be one only if context is lost. If Core fails to enter off state, then there is no need to restore context.

Vishwa
>  #endif
> 
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RE: [PATCH] usb: musb: Offmode fix for idle path

[Kalliguddi, Hema]

 Hello,

>-----Original Message-----
>From: Sergei Shtylyov [mailto:sshtylyov@mvista.com] 
>Sent: Thursday, July 08, 2010 6:58 PM
>To: Kalliguddi, Hema
>Cc: linux-usb@vger.kernel.org; linux-omap@vger.kernel.org; 
>Mankad, Maulik Ojas; Felipe Balbi; Tony Lindgren; Kevin Hilman
>Subject: Re: [PATCH] usb: musb: Offmode fix for idle path
>
>Hello.
>
>Hema HK wrote:
>
>> With OMAP coreoff support usb was not functional as context 
>was getting
>> lost after wakeup from coreoff. And also usb was blocking 
>the coreoff 
>
>    USB is an acronym.
>
Agree I will change it accordingly.

>> after loading the gadget driver even with no cable connected 
>sometimes.
>
>> Added the conext save/restore api in the platform layer which will
>
>    API is an acronym.
>
Agree.

>> be called in the idle and wakeup path.
>
>> Changed the usb sysconfig settings as per the usbotg functional spec.
>
>    Do you mean the OTG supplement to USB 2.0 spec. or something else?
>
No it is TI OMAP USBOTG functional specifications.

>> When the device is not used, configure in 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.
>
>> Since clock used for musb is auto gated, there is no need to 
>specifically
>> enable/disable the clock. Removed enable/disable clock in 
>suspend resume api.
>
>    I'm not sure it's auto-gated on all platforms...

Might be. need to check this. 

Blackfin guys,
Please comment...

>
>> Signed-off-by: Hema HK <hemahk@ti.com>
>> Signed-off-by: Maulik Mankad <x0082077@ti.com>
>
>> Cc: Felipe Balbi <felipe.balbi@nokia.com>
>> Cc: Tony Lindgren <tony@atomide.com>
>> Cc: Kevin Hilman <khilman@deeprootsystems.com>
>
>> Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
>> ===================================================================
>> --- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c
>> +++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
>> @@ -177,6 +177,21 @@ void __init usb_musb_init(struct omap_mu
>>  	usb_musb_pm_init();
>>  }
>>  
>> +void musb_context_save_restore(int save)
>> +{
>> +	struct device *dev = &musb_device.dev;
>> +	struct device_driver *drv = dev->driver;
>
>    Need an empty line here.
>
OK.
>> +	if (dev->driver) {
>
>   You've just assigned that to 'drv' -- why not use it?
>
I will do that.

>> Index: linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
>> ===================================================================
>> --- linux-omap-pm.orig/arch/arm/plat-omap/include/plat/usb.h
>> +++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
>> @@ -82,6 +82,8 @@ extern void usb_ohci_init(const struct o
>>  /* This is needed for OMAP3 errata 1.164: enabled autoidle 
>can prevent sleep */
>>  extern void usb_musb_disable_autoidle(void);
>>  
>> +/* For saving and restoring the musb context during off/wakeup*/
>> +extern void musb_context_save_restore(int save);
>>  #endif
>>  
>>  void omap_usb_init(struct omap_usb_config *pdata);
>> Index: linux-omap-pm/drivers/usb/musb/musb_core.c
>> ===================================================================
>> --- linux-omap-pm.orig/drivers/usb/musb/musb_core.c
>> +++ linux-omap-pm/drivers/usb/musb/musb_core.c
>> @@ -2430,11 +2430,6 @@ static int musb_suspend(struct device *d
>>  	}
>>  
>>  	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;
>>  }
>> @@ -2446,12 +2441,6 @@ static int musb_resume_noirq(struct devi
>>  
>>  	if (!musb->clock)
>>  		return 0;
>> -
>> -	if (musb->set_clock)
>> -		musb->set_clock(musb->clock, 1);
>> -	else
>> -		clk_enable(musb->clock);
>> -
>
>    OK, maybe for OMAP the clock is auto-gated but what about 
>the other platforms?
>

For OMAP it is autogated. 

Blackfin guys comments please?

>>  	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
>> +++ linux-omap-pm/drivers/usb/musb/omap2430.c
>> @@ -257,15 +257,39 @@ int __init musb_platform_init(struct mus
>>  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 specification, configure it to forced standby
>> +	 * and  force idle mode when no activity on usb.
>> +	 */
>> +	void __iomem *musb_base = musb->mregs;
>
>    Need an empty line here.
>
OK. 
>> +	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));
>
>    Parens around AUTOIDLE are not useful.
>

OK. I will remove.
>> +
>> +	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 specification, configure it smart standby
>> +	 * and smart idle during operation.
>> +	 */
>> +	void __iomem *musb_base = musb->mregs;
>
>   Need an empty line here.
OK.
>
>> +	musb_writel(musb_base, OTG_FORCESTDBY, 0);
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +				OTG_SYSCONFIG) | (SMARTSTDBY));
>
>    Parens around SMARTSTDBY are not useful.
>
OK. I will remove.
>> +
>> +	musb_writel(musb_base, OTG_SYSCONFIG, musb_readl(musb_base,
>> +					OTG_SYSCONFIG) | (SMARTIDLE));
>
>    Ditto about parens around SMARTIDLE...
>
OK I will remove.
>WBR, Sergei
>
~Hema

RE: [PATCH] usb: musb: Offmode fix for idle path

[Kalliguddi, Hema]

 Hello,


>-----Original Message-----
>From: Sripathy, Vishwanath 
>Sent: Thursday, July 08, 2010 7:14 PM
>To: Kalliguddi, Hema; linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; 
>linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>Cc: Mankad, Maulik Ojas; Felipe Balbi; Tony Lindgren; Kevin Hilman
>Subject: RE: [PATCH] usb: musb: Offmode fix for idle path
>
>Hema,
>
>> -----Original Message-----
>> From: linux-omap-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-omap-
>> owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Kalliguddi, Hema
>> Sent: Thursday, July 08, 2010 3:59 PM
>> To: linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Cc: Kalliguddi, Hema; Mankad, Maulik Ojas; Felipe Balbi; 
>Tony Lindgren; Kevin Hilman
>> Subject: [PATCH] usb: musb: Offmode fix for idle path
>> 
>> From: Hema HK  <hemahk-l0cyMroinI0@public.gmane.org>
>> 
>> With OMAP coreoff support usb was not functional as context 
>was getting
>> lost after wakeup from coreoff. And also usb was blocking the coreoff
>> 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 used, configure in 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.
>> 
>> Since clock used for musb is auto gated, there is no need to 
>specifically
>> enable/disable the clock. Removed enable/disable clock in 
>suspend resume api.
>> 
>> Signed-off-by: Hema HK <hemahk-l0cyMroinI0@public.gmane.org>
>> Signed-off-by: Maulik Mankad <x0082077-l0cyMroinI0@public.gmane.org>
>> 
>> Cc: Felipe Balbi <felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
>> Cc: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>> Cc: Kevin Hilman <khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
>> ---
>> Based off : Kevin pm branch.
>> 
>>  arch/arm/mach-omap2/pm34xx.c          |    4 ++++
>>  arch/arm/mach-omap2/usb-musb.c        |   15 +++++++++++++++
>>  arch/arm/plat-omap/include/plat/usb.h |    2 ++
>>  drivers/usb/musb/musb_core.c          |   11 -----------
>>  drivers/usb/musb/omap2430.c           |   32
>> ++++++++++++++++++++++++++++----
>>  5 files changed, 49 insertions(+), 15 deletions(-)
>> 
>> Index: linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
>> =====================================================
>> ==============
>> --- linux-omap-pm.orig/arch/arm/mach-omap2/pm34xx.c
>> +++ linux-omap-pm/arch/arm/mach-omap2/pm34xx.c
>> @@ -431,6 +431,8 @@ void omap_sram_idle(void)
>>  		if (core_next_state == PWRDM_POWER_OFF) {
>>  			omap3_core_save_context();
>>  			omap3_prcm_save_context();
>> +			/* Save MUSB context */
>> +			musb_context_save_restore(1);
>Do you really need to save and restore USB context in every OS 
>Idle? Can't it be done on a need basis like when USB is connected?

No. There are some transperent PHYs in which the connect/disconnect events 
are not reported as interrupts. 
In that case there is no way know when to save and restore. 
We can do the optimization of saving the context only when needed.

>>  		}
>>  	}
>> 
>> @@ -479,6 +481,8 @@ void omap_sram_idle(void)
>>  			omap3_prcm_restore_context();
>>  			omap3_sram_restore_context();
>>  			omap2_sms_restore_context();
>> +			/* Restore MUSB context */
>> +			musb_context_save_restore(0);
>>  			/*
>>  			 * Errata 1.164 fix : OTG autoidle can prevent
>>  			 * sleep
>> Index: linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
>> =====================================================
>> ==============
>> --- linux-omap-pm.orig/arch/arm/mach-omap2/usb-musb.c
>> +++ linux-omap-pm/arch/arm/mach-omap2/usb-musb.c
>> @@ -177,6 +177,21 @@ void __init usb_musb_init(struct omap_mu
>>  	usb_musb_pm_init();
>>  }
>> 
>> +void musb_context_save_restore(int save)
>> +{
>> +	struct device *dev = &musb_device.dev;
>> +	struct device_driver *drv = dev->driver;
>> +	if (dev->driver) {
>> +
>> +		const struct dev_pm_ops *pm = drv->pm;
>> +
>> +		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
>> +++ linux-omap-pm/arch/arm/plat-omap/include/plat/usb.h
>> @@ -82,6 +82,8 @@ extern void usb_ohci_init(const struct o
>>  /* This is needed for OMAP3 errata 1.164: enabled autoidle 
>can prevent sleep */
>>  extern void usb_musb_disable_autoidle(void);
>> 
>> +/* For saving and restoring the musb context during off/wakeup*/
>> +extern void musb_context_save_restore(int save);
>>  #endif
>> 
>>  void omap_usb_init(struct omap_usb_config *pdata);
>> Index: linux-omap-pm/drivers/usb/musb/musb_core.c
>> =====================================================
>> ==============
>> --- linux-omap-pm.orig/drivers/usb/musb/musb_core.c
>> +++ linux-omap-pm/drivers/usb/musb/musb_core.c
>> @@ -2430,11 +2430,6 @@ static int musb_suspend(struct device *d
>>  	}
>> 
>>  	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;
>>  }
>> @@ -2446,12 +2441,6 @@ static int musb_resume_noirq(struct devi
>> 
>>  	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
>> +++ linux-omap-pm/drivers/usb/musb/omap2430.c
>> @@ -257,15 +257,39 @@ int __init musb_platform_init(struct mus
>>  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 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);
>>  }
>
>Since this is called from OS Idle, I would suggest to optimize 
>this code so that you will save the context only when 
>currently saved context is different from the already stored 
>one. Otherwise you will end of saving the same context every 
>time unnecessary. 

We can do the optimization here.

>> 
>>  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 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));
>>  }
>Restore should be one only if context is lost. If Core fails 
>to enter off state, then there is no need to restore context.
>
This is already taken care since the restore is only done if the previous state is
COREOFF.

>Vishwa

~Hema
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