Re: [PATCH (mmc-next)] mmc: improve the SDHCI wake-up support [RFC: V2]

[Peppe CAVALLARO <peppe.cavallaro@st.com>]

Hello

On 11/15/2010 3:53 PM, Giuseppe CAVALLARO wrote:
>
> This patch allows the SDHCI to wake up the system
> on the following events:
>  1) Card Interrupts.
>  2) Card Insertion.
>  3) Card Removal.
>
Any comments and advice for this patch?

Regards
Peppe

>
> Indeed, on a set-top-box, it can be nice to have the
> capability to wake-up the system when a card is inserted.
>
> These new module parameters have been added to select
> which events have to wake-up the system:
>  o wake_on_card_int
>  o wake_on_card_ins
>  o wake_on_card_rem
>
> Ex:
> $ echo 1 > /sys/module/sdhci/parameters/wakeup_card_ins
>
> A new quirk has been also added to allow hosts, based
> on sdhci d.d., to set the device as wake-up capable.
>
> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> ---
>  drivers/mmc/host/sdhci-pci.c |    2 +-
>  drivers/mmc/host/sdhci.c     |  104
> ++++++++++++++++++++++++++++++++++++++----
>  drivers/mmc/host/sdhci.h     |    2 +-
>  include/linux/mmc/sdhci.h    |    2 +
>  4 files changed, 99 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
> index 3d9c246..de610f1 100644
> --- a/drivers/mmc/host/sdhci-pci.c
> +++ b/drivers/mmc/host/sdhci-pci.c
> @@ -668,7 +668,7 @@ static int sdhci_pci_suspend (struct pci_dev
> *pdev, pm_message_t state)
>
>                 slot_pm_flags = slot->host->mmc->pm_flags;
>                 if (slot_pm_flags & MMC_PM_WAKE_SDIO_IRQ)
> -                       sdhci_enable_irq_wakeups(slot->host);
> +                       sdhci_enable_irq_wakeups(slot->host,
> SDHCI_WAKE_ON_INT);
>
>                 pm_flags |= slot_pm_flags;
>         }
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 154cbf8..531033e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -37,7 +37,20 @@
>  #define SDHCI_USE_LEDS_CLASS
>  #endif
>
> -static unsigned int debug_quirks = 0;
> +static unsigned int debug_quirks;
> +#ifdef CONFIG_PM
> +static unsigned int wakeup_card_int;
> +module_param(wakeup_card_int, uint, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(wakeup_card_int, "Wake Up on Card interrupt event");
> +
> +static unsigned int wakeup_card_ins;
> +module_param(wakeup_card_ins, uint, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(wakeup_card_ins, "Wake UP on Card insertion event");
> +
> +static unsigned int wakeup_card_rem;
> +module_param(wakeup_card_rem, uint, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(wakeup_card_rem, "Wake UP on Card removal event");
> +#endif /* CONFIG_PM */
>
>  static void sdhci_prepare_data(struct sdhci_host *, struct mmc_data *);
>  static void sdhci_finish_data(struct sdhci_host *);
> @@ -1629,6 +1642,71 @@ out:
>
>  #ifdef CONFIG_PM
>
> +static void sdhci_can_wakeup(struct sdhci_host *host)
> +{
> +       struct device *dev = host->mmc->parent;
> +
> +       /* SDHCI is capable to wakeup the system */
> +       device_set_wakeup_capable(dev, 1);
> +
> +       /* Enable wakeup */
> +       device_set_wakeup_enable(dev, 1);
> +       enable_irq_wake(host->irq);
> +}
> +
> +/*
> + * According to the SD SPEC to wake up the system
> + * the HC has to be programmed as below:
> + * - SD Bus power: ON
> + * - SD clock: Stop
> + * - Internal clock: Oscillate
> + * - Data transfer witdh: 0
> + *
> + * While suspending we have to:
> + * 1) Set BUS width to 1
> + * 2) Mask the Signal Interrupt register
> + * 3) Clean the Signal Interrupt register
> + * 4) Set the enable bits of each factor to 1 in the Wakeup
> + *    control register
> + * 5) Set the bits of Normal Interrupt Status Enable register
> + *    to use wakeup.
> + */
> +static void sdhci_set_wakeup(struct sdhci_host *host)
> +{
> +       u16 clk;
> +       u8 pwr;
> +       mmc_pm_flag_t wakeflag = 0;
> +
> +       clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +       clk &= ~SDHCI_CLOCK_CARD_EN;
> +       clk |= SDHCI_CLOCK_INT_EN;
> +       sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> +       pwr = sdhci_readb(host, SDHCI_POWER_CONTROL);
> +       pwr |= SDHCI_POWER_ON;
> +       sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> +
> +       sdhci_mask_irqs(host, SDHCI_INT_NORMAL_MASK |
> +                       SDHCI_INT_ERROR_MASK);
> +       sdhci_writel(host, 0, SDHCI_INT_STATUS);
> +       sdhci_writel(host, 0, SDHCI_SIGNAL_ENABLE);
> +       sdhci_writel(host, SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT |
> +                    SDHCI_INT_CARD_INT, SDHCI_INT_ENABLE);
> +       /*
> +        * Program the Wakeup Control register according to the event
> selected.
> +        * If there is no event (SDHCI_WAKE_UP_CONTROL = 0x0) so the
> device
> +        * won't be able to wake up the system.
> +        */
> +       if (wakeup_card_int)
> +               wakeflag |= SDHCI_WAKE_ON_INT;
> +       if (wakeup_card_ins)
> +               wakeflag |= SDHCI_WAKE_ON_INSERT;
> +       if (wakeup_card_rem)
> +               wakeflag |= SDHCI_WAKE_ON_REMOVE;
> +
> +       sdhci_enable_irq_wakeups(host, wakeflag);
> +}
> +
>  int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
>  {
>         int ret;
> @@ -1639,7 +1717,10 @@ int sdhci_suspend_host(struct sdhci_host *host,
> pm_message_t state)
>         if (ret)
>                 return ret;
>
> -       free_irq(host->irq, host);
> +       if (device_may_wakeup(host->mmc->parent))
> +               sdhci_set_wakeup(host);
> +       else
> +               free_irq(host->irq, host);
>
>         if (host->vmmc)
>                 ret = regulator_disable(host->vmmc);
> @@ -1665,11 +1746,12 @@ int sdhci_resume_host(struct sdhci_host *host)
>                         host->ops->enable_dma(host);
>         }
>
> -       ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
> -                         mmc_hostname(host->mmc), host);
> -       if (ret)
> -               return ret;
> -
> +       if (!(device_may_wakeup(host->mmc->parent))) {
> +               ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
> +                                 mmc_hostname(host->mmc), host);
> +               if (ret)
> +                       return ret;
> +       }
>         sdhci_init(host, (host->mmc->pm_flags & MMC_PM_KEEP_POWER));
>         mmiowb();
>
> @@ -1681,11 +1763,11 @@ int sdhci_resume_host(struct sdhci_host *host)
>
>  EXPORT_SYMBOL_GPL(sdhci_resume_host);
>
> -void sdhci_enable_irq_wakeups(struct sdhci_host *host)
> +void sdhci_enable_irq_wakeups(struct sdhci_host *host, int mode)
>  {
>         u8 val;
>         val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
> -       val |= SDHCI_WAKE_ON_INT;
> +       val |= mode;
>         sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
>  }
>
> @@ -1987,6 +2069,10 @@ int sdhci_add_host(struct sdhci_host *host)
>
>         sdhci_enable_card_detection(host);
>
> +#ifdef CONFIG_PM
> +       if (host->quirks & SDHCI_QUIRK_WANT_WAKEUP_ON_CARD)
> +               sdhci_can_wakeup(host);
> +#endif
>         return 0;
>
>  #ifdef SDHCI_USE_LEDS_CLASS
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index d52a716..1682542 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -320,7 +320,7 @@ extern void sdhci_remove_host(struct sdhci_host
> *host, int dead);
>  #ifdef CONFIG_PM
>  extern int sdhci_suspend_host(struct sdhci_host *host, pm_message_t
> state);
>  extern int sdhci_resume_host(struct sdhci_host *host);
> -extern void sdhci_enable_irq_wakeups(struct sdhci_host *host);
> +extern void sdhci_enable_irq_wakeups(struct sdhci_host *host, int mode);
>  #endif
>
>  #endif /* __SDHCI_HW_H */
> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
> index 1fdc673..8aa3c2e 100644
> --- a/include/linux/mmc/sdhci.h
> +++ b/include/linux/mmc/sdhci.h
> @@ -83,6 +83,8 @@ struct sdhci_host {
>  #define SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12             (1<<28)
>  /* Controller doesn't have HISPD bit field in HI-SPEED SD card */
>  #define SDHCI_QUIRK_NO_HISPD_BIT                       (1<<29)
> +/* Controller wants to wakeup on card events, i.e. card ins, rem or
> int */
> +#define SDHCI_QUIRK_WANT_WAKEUP_ON_CARD                        (1<<30)
>
>         int irq;                /* Device IRQ */
>         void __iomem *ioaddr;   /* Mapped address */
> --
> 1.5.5.6
>