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

["Cousson, Benoit" <b-cousson-l0cyMroinI0@public.gmane.org>]

On 8/6/2010 7:27 PM, Kalliguddi, Hema wrote:
> From: Hema HK<hemahk-l0cyMroinI0@public.gmane.org>
>
> 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

>
> 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>
> ---
>
>   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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