Re: [PATCH 2/3 v3] musb: Add context save and restore support

[Arnaud Mandy <ext-arnaud.2.mandy@xxxxxxxxx>]

ext Ajay Kumar Gupta wrote:
> Adding support for MUSB register save and restore during system
> suspend and resume.
>
> Changes:
>         - Added musb_save/restore_context() functions
>         - Added platform specific musb_platform_save/restore_context()
>           to handle platform specific jobs.
>         - Maintaining BlackFin compatibility by adding read/write
>           functions for registers which are not available in BlackFin
>
> Tested system suspend and resume on OMAP3EVM board.
>
> Signed-off-by: Anand Gadiyar <gadiyar@xxxxxx>
> Signed-off-by: Ajay Kumar Gupta <ajay.gupta@xxxxxx>
> ---
> Changes from v2:
>         - Saving/Restoring host only registers within is_host_enabled() check.
>         - Saving/Restoring Tx/Rx FIFOSZ/FIFOADDR within musb->dynfifo check.
>
>  drivers/usb/musb/musb_core.c |  157 +++++++++++++++++++++++++++++++++++++++++-
>  drivers/usb/musb/musb_core.h |   39 ++++++++++
>  drivers/usb/musb/musb_regs.h |   90 ++++++++++++++++++++++++
>  drivers/usb/musb/omap2430.c  |   16 ++++
>  4 files changed, 300 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index d4adbbf..cd4462b 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -2167,11 +2167,154 @@ static int __devexit musb_remove(struct platform_device *pdev)
>
>  #ifdef CONFIG_PM
>
> +static struct musb_context_registers musb_context;
> +
> +void musb_save_context(struct musb *musb)
> +{
>   

Could you add one more parameter to this function call, which would 
select either if we want to save the musb_platform context or not?
I m working at the moment on turning off the musb when cable unplugged 
and turning it on with restoring context after cable re-connect.
In this case I don't need to restore the the musb_platform_context since 
I just set them before calling this one.

Same apply for restore.

what do you think?
I could also modify slightly this implementation after it is ready and 
submit it.

> +       int i;
> +       void __iomem *musb_base = musb->mregs;
> +
> +       if (is_host_enabled(musb)) {
> +               musb_context.frame = musb_readw(musb_base, MUSB_FRAME);
> +               musb_context.testmode = musb_readb(musb_base, MUSB_TESTMODE);
> +       }
> +       musb_context.power = musb_readb(musb_base, MUSB_POWER);
> +       musb_context.intrtxe = musb_readw(musb_base, MUSB_INTRTXE);
> +       musb_context.intrrxe = musb_readw(musb_base, MUSB_INTRRXE);
> +       musb_context.intrusbe = musb_readb(musb_base, MUSB_INTRUSBE);
> +       musb_context.index = musb_readb(musb_base, MUSB_INDEX);
> +       musb_context.devctl = musb_readb(musb_base, MUSB_DEVCTL);
> +
> +       for (i = 0; i < MUSB_C_NUM_EPS; ++i) {
> +               musb_writeb(musb_base, MUSB_INDEX, i);
> +               musb_context.index_regs[i].txmaxp =
> +                       musb_readw(musb_base, 0x10 + MUSB_TXMAXP);
> +               musb_context.index_regs[i].txcsr =
> +                       musb_readw(musb_base, 0x10 + MUSB_TXCSR);
> +               musb_context.index_regs[i].rxmaxp =
> +                       musb_readw(musb_base, 0x10 + MUSB_RXMAXP);
> +               musb_context.index_regs[i].rxcsr =
> +                       musb_readw(musb_base, 0x10 + MUSB_RXCSR);
> +
> +               if (musb->dyn_fifo) {
> +                       musb_context.index_regs[i].txfifoadd =
> +                                       musb_read_txfifoadd(musb_base);
> +                       musb_context.index_regs[i].rxfifoadd =
> +                                       musb_read_rxfifoadd(musb_base);
> +                       musb_context.index_regs[i].txfifosz =
> +                                       musb_read_txfifosz(musb_base);
> +                       musb_context.index_regs[i].rxfifosz =
> +                                       musb_read_rxfifosz(musb_base);
> +               }
> +               if (is_host_enabled(musb)) {
> +                       musb_context.index_regs[i].txtype =
> +                               musb_readb(musb_base, 0x10 + MUSB_TXTYPE);
> +                       musb_context.index_regs[i].txinterval =
> +                               musb_readb(musb_base, 0x10 + MUSB_TXINTERVAL);
> +                       musb_context.index_regs[i].rxtype =
> +                               musb_readb(musb_base, 0x10 + MUSB_RXTYPE);
> +                       musb_context.index_regs[i].rxinterval =
> +                               musb_readb(musb_base, 0x10 + MUSB_RXINTERVAL);
> +
> +                       musb_context.index_regs[i].txfunaddr =
> +                               musb_read_txfunaddr(musb_base, i);
> +                       musb_context.index_regs[i].txhubaddr =
> +                               musb_read_txhubaddr(musb_base, i);
> +                       musb_context.index_regs[i].txhubport =
> +                               musb_read_txhubport(musb_base, i);
> +
> +                       musb_context.index_regs[i].rxfunaddr =
> +                               musb_read_rxfunaddr(musb_base, i);
> +                       musb_context.index_regs[i].rxhubaddr =
> +                               musb_read_rxhubaddr(musb_base, i);
> +                       musb_context.index_regs[i].rxhubport =
> +                               musb_read_rxhubport(musb_base, i);
> +               }
> +       }
> +
> +       musb_writeb(musb_base, MUSB_INDEX, musb_context.index);
> +
> +       musb_platform_save_context(&musb_context);
> +}
> +
> +void musb_restore_context(struct musb *musb)
> +{
> +       int i;
> +       void __iomem *musb_base = musb->mregs;
> +       void __iomem *ep_target_regs;
> +
> +       musb_platform_restore_context(&musb_context);
> +
> +       if (is_host_enabled(musb)) {
> +               musb_writew(musb_base, MUSB_FRAME, musb_context.frame);
> +               musb_writeb(musb_base, MUSB_TESTMODE, musb_context.testmode);
> +       }
> +       musb_writeb(musb_base, MUSB_POWER, musb_context.power);
> +       musb_writew(musb_base, MUSB_INTRTXE, musb_context.intrtxe);
> +       musb_writew(musb_base, MUSB_INTRRXE, musb_context.intrrxe);
> +       musb_writeb(musb_base, MUSB_INTRUSBE, musb_context.intrusbe);
> +       musb_writeb(musb_base, MUSB_DEVCTL, musb_context.devctl);
> +
> +       for (i = 0; i < MUSB_C_NUM_EPS; ++i) {
> +               musb_writeb(musb_base, MUSB_INDEX, i);
> +               musb_writew(musb_base, 0x10 + MUSB_TXMAXP,
> +                       musb_context.index_regs[i].txmaxp);
> +               musb_writew(musb_base, 0x10 + MUSB_TXCSR,
> +                       musb_context.index_regs[i].txcsr);
> +               musb_writew(musb_base, 0x10 + MUSB_RXMAXP,
> +                       musb_context.index_regs[i].rxmaxp);
> +               musb_writew(musb_base, 0x10 + MUSB_RXCSR,
> +                       musb_context.index_regs[i].rxcsr);
> +
> +               if (musb->dyn_fifo) {
> +                       musb_write_txfifosz(musb_base,
> +                               musb_context.index_regs[i].txfifosz);
> +                       musb_write_rxfifosz(musb_base,
> +                               musb_context.index_regs[i].rxfifosz);
> +                       musb_write_txfifoadd(musb_base,
> +                               musb_context.index_regs[i].txfifoadd);
> +                       musb_write_rxfifoadd(musb_base,
> +                               musb_context.index_regs[i].rxfifoadd);
> +               }
> +
> +               if (is_host_enabled(musb)) {
> +                       musb_writeb(musb_base, 0x10 + MUSB_TXTYPE,
> +                               musb_context.index_regs[i].txtype);
> +                       musb_writeb(musb_base, 0x10 + MUSB_TXINTERVAL,
> +                               musb_context.index_regs[i].txinterval);
> +                       musb_writeb(musb_base, 0x10 + MUSB_RXTYPE,
> +                               musb_context.index_regs[i].rxtype);
> +                       musb_writeb(musb_base, 0x10 + MUSB_RXINTERVAL,
> +
> +                       musb_context.index_regs[i].rxinterval);
> +                       musb_write_txfunaddr(musb_base, i,
> +                               musb_context.index_regs[i].txfunaddr);
> +                       musb_write_txhubaddr(musb_base, i,
> +                               musb_context.index_regs[i].txhubaddr);
> +                       musb_write_txhubport(musb_base, i,
> +                               musb_context.index_regs[i].txhubport);
> +
> +                       ep_target_regs =
> +                               musb_read_target_reg_base(i, musb_base);
> +
> +                       musb_write_rxfunaddr(ep_target_regs,
> +                               musb_context.index_regs[i].rxfunaddr);
> +                       musb_write_rxhubaddr(ep_target_regs,
> +                               musb_context.index_regs[i].rxhubaddr);
> +                       musb_write_rxhubport(ep_target_regs,
> +                               musb_context.index_regs[i].rxhubport);
> +               }
> +       }
> +
> +       musb_writeb(musb_base, MUSB_INDEX, musb_context.index);
> +}
> +
>  static int musb_suspend(struct device *dev)
>  {
>         struct platform_device *pdev = to_platform_device(dev);
>         unsigned long   flags;
>         struct musb     *musb = dev_to_musb(&pdev->dev);
> +       u8 reg;
>
>         if (!musb->clock)
>                 return 0;
> @@ -2179,15 +2322,23 @@ static int musb_suspend(struct device *dev)
>         spin_lock_irqsave(&musb->lock, flags);
>
>         if (is_peripheral_active(musb)) {
> -               /* FIXME force disconnect unless we know USB will wake
> -                * the system up quickly enough to respond ...
> +               /* System is entering into suspend where gadget would not be
> +                * able to respond to host and thus it will be in an unknown
> +                * state for host. Re-enumeration of gadget is required after
> +                * a resume. So we force a disconnect.
>                  */
> +               reg = musb_readb(musb->mregs, MUSB_POWER);
> +               reg &= ~MUSB_POWER_SOFTCONN;
> +               musb_writeb(musb->mregs, MUSB_POWER, reg);
> +
>         } else if (is_host_active(musb)) {
>                 /* we know all the children are suspended; sometimes
>                  * they will even be wakeup-enabled.
>                  */
>         }
>
> +       musb_save_context(musb);
> +
>         if (musb->set_clock)
>                 musb->set_clock(musb->clock, 0);
>         else
> @@ -2209,6 +2360,8 @@ static int musb_resume_noirq(struct device *dev)
>         else
>                 clk_enable(musb->clock);
>
> +       musb_restore_context(musb);
> +
>         /* for static cmos like DaVinci, register values were preserved
>          * unless for some reason the whole soc powered down or the USB
>          * module got reset through the PSC (vs just being disabled).
> diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
> index 969287c..38de1be 100644
> --- a/drivers/usb/musb/musb_core.h
> +++ b/drivers/usb/musb/musb_core.h
> @@ -462,6 +462,45 @@ struct musb {
>  #endif
>  };
>
> +#ifdef CONFIG_PM
> +struct musb_csr_regs {
> +       /* FIFO registers */
> +       u16 txmaxp, txcsr, rxmaxp, rxcsr;
> +       u16 rxfifoadd, txfifoadd;
> +       u8 txtype, txinterval, rxtype, rxinterval;
> +       u8 rxfifosz, txfifosz;
> +       u8 txfunaddr, txhubaddr, txhubport;
> +       u8 rxfunaddr, rxhubaddr, rxhubport;
> +};
> +
> +struct musb_context_registers {
> +
> +#if defined(CONFIG_ARCH_OMAP34XX)
> +       u32 otg_sysconfig, otg_forcestandby;
> +#endif
> +       u8 power;
> +       u16 intrtxe, intrrxe;
> +       u8 intrusbe;
> +       u16 frame;
> +       u8 index, testmode;
> +
> +       u8 devctl, misc;
> +
> +       struct musb_csr_regs index_regs[MUSB_C_NUM_EPS];
> +};
> +
> +#if defined(CONFIG_ARCH_OMAP34XX) || defined(CONFIG_ARCH_OMAP2430)
> +extern void musb_platform_save_context(struct musb_context_registers
> +               *musb_context);
> +extern void musb_platform_restore_context(struct musb_context_registers
> +               *musb_context);
> +#else
> +#define musb_platform_save_context(x)          do {} while (0)
> +#define musb_platform_restore_context(x)       do {} while (0)
> +#endif
> +
> +#endif
> +
>  static inline void musb_set_vbus(struct musb *musb, int is_on)
>  {
>         musb->board_set_vbus(musb, is_on);
> diff --git a/drivers/usb/musb/musb_regs.h b/drivers/usb/musb/musb_regs.h
> index 473a94e..8ca8f23 100644
> --- a/drivers/usb/musb/musb_regs.h
> +++ b/drivers/usb/musb/musb_regs.h
> @@ -321,6 +321,26 @@ static inline void  musb_write_rxfifoadd(void __iomem *mbase, u16 c_off)
>         musb_writew(mbase, MUSB_RXFIFOADD, c_off);
>  }
>
> +static inline u8 musb_read_txfifosz(void __iomem *mbase)
> +{
> +       return musb_readb(mbase, MUSB_TXFIFOSZ);
> +}
> +
> +static inline u16 musb_read_txfifoadd(void __iomem *mbase)
> +{
> +       return musb_readw(mbase, MUSB_TXFIFOADD);
> +}
> +
> +static inline u8 musb_read_rxfifosz(void __iomem *mbase)
> +{
> +       return musb_readb(mbase, MUSB_RXFIFOSZ);
> +}
> +
> +static inline u16  musb_read_rxfifoadd(void __iomem *mbase)
> +{
> +       return musb_readw(mbase, MUSB_RXFIFOADD);
> +}
> +
>  static inline u8 musb_read_configdata(void __iomem *mbase)
>  {
>         musb_writeb(mbase, MUSB_INDEX, 0);
> @@ -376,6 +396,36 @@ static inline void  musb_write_txhubport(void __iomem *mbase, u8 epnum,
>                         qh_h_port_reg);
>  }
>
> +static inline u8 musb_read_rxfunaddr(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXFUNCADDR));
> +}
> +
> +static inline u8 musb_read_rxhubaddr(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXHUBADDR));
> +}
> +
> +static inline u8 musb_read_rxhubport(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXHUBPORT));
> +}
> +
> +static inline u8  musb_read_txfunaddr(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXFUNCADDR));
> +}
> +
> +static inline u8  musb_read_txhubaddr(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBADDR));
> +}
> +
> +static inline u8  musb_read_txhubport(void __iomem *mbase, u8 epnum)
> +{
> +       return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBPORT));
> +}
> +
>  #else /* CONFIG_BLACKFIN */
>
>  #define USB_BASE               USB_FADDR
> @@ -455,6 +505,22 @@ static inline void  musb_write_rxfifoadd(void __iomem *mbase, u16 c_off)
>  {
>  }
>
> +static inline u8 musb_read_txfifosz(void __iomem *mbase)
> +{
> +}
> +
> +static inline u16 musb_read_txfifoadd(void __iomem *mbase)
> +{
> +}
> +
> +static inline u8 musb_read_rxfifosz(void __iomem *mbase)
> +{
> +}
> +
> +static inline u16  musb_read_rxfifoadd(void __iomem *mbase)
> +{
> +}
> +
>  static inline u8 musb_read_configdata(void __iomem *mbase)
>  {
>         return 0;
> @@ -500,6 +566,30 @@ static inline void  musb_write_txhubport(void __iomem *mbase, u8 epnum,
>  {
>  }
>
> +static inline u8 musb_read_rxfunaddr(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
> +static inline u8 musb_read_rxhubaddr(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
> +static inline u8 musb_read_rxhubport(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
> +static inline u8  musb_read_txfunaddr(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
> +static inline u8  musb_read_txhubaddr(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
> +static inline void  musb_read_txhubport(void __iomem *mbase, u8 epnum)
> +{
> +}
> +
>  #endif /* CONFIG_BLACKFIN */
>
>  #endif /* __MUSB_REGS_H__ */
> diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
> index 83beeac..15a3f27 100644
> --- a/drivers/usb/musb/omap2430.c
> +++ b/drivers/usb/musb/omap2430.c
> @@ -255,6 +255,22 @@ int __init musb_platform_init(struct musb *musb)
>         return 0;
>  }
>
> +#ifdef CONFIG_PM
> +void musb_platform_save_context(struct musb_context_registers
> +               *musb_context)
> +{
> +       musb_context->otg_sysconfig = omap_readl(OTG_SYSCONFIG);
> +       musb_context->otg_forcestandby = omap_readl(OTG_FORCESTDBY);
> +}
> +
> +void musb_platform_restore_context(struct musb_context_registers
> +               *musb_context)
> +{
> +       omap_writel(musb_context->otg_sysconfig, OTG_SYSCONFIG);
> +       omap_writel(musb_context->otg_forcestandby, OTG_FORCESTDBY);
> +}
> +#endif
> +
>  int musb_platform_suspend(struct musb *musb)
>  {
>         u32 l;
> --
> 1.6.2.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>   

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html