| Message ID | BANLkTi=7h_gBQ1CGqYgUUhZabcwVuoRhCw@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Thu, Apr 21, 2011 at 3:51 AM, Barry Song <21cnbao@gmail.com> wrote: > From: Bin Shi <bin.shi@csr.com> > > some controllers share data bus or other pins between > multi-controllers and need to switch the functions of shared pins > runtime > this patch requested those shared pins before actual hardware access > and release them after access > > Signed-off-by: Bin Shi <bin.shi@csr.com> > Cc: Binghua Duan <binghua.duan@csr.com> > Signed-off-by: Barry Song <21cnbao@gmail.com> > --- > drivers/mmc/host/sdhci.c | 13 +++++++++++++ > drivers/mmc/host/sdhci.h | 2 ++ > include/linux/mmc/sdhci.h | 2 ++ > 3 files changed, 17 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index f31077d..7b07152 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -1379,6 +1379,13 @@ static void sdhci_tasklet_finish(unsigned long param) > sdhci_reset(host, SDHCI_RESET_DATA); > } > > + /* > + * some controllers share data bus or other pins between multi-controller > + * and need to switch the function of pins runtime > + */ > + if (host->quirks & SDHCI_QUIRK_SHARED_PINS) > + host->ops->get_shared_pins(host); > + Why in tasklet_finish? Why not in sdhci_request? No need to waste a quirk flag. Just invoke if method is not NULL. Also, I would assume host->ops->get_shared_pins would need to synchronize with other SDHCI instances it shares the pins with. Since you do it after the host->lock (as you should), what happens if get_shared_pins needs to wait? Can you show the rest (sdhci driver implementing these hooks)? > host->mrq = NULL; > host->cmd = NULL; > host->data = NULL; > @@ -1391,6 +1398,12 @@ static void sdhci_tasklet_finish(unsigned long param) > spin_unlock_irqrestore(&host->lock, flags); > > mmc_request_done(host->mmc, mrq); > + > + /* > + * release shared pins so that other controllers can use them > + */ > + if (host->quirks & SDHCI_QUIRK_SHARED_PINS) > + host->ops->get_shared_pins(host); > } > > static void sdhci_timeout_timer(unsigned long data) > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > index 85750a9..9d918a5 100644 > --- a/drivers/mmc/host/sdhci.h > +++ b/drivers/mmc/host/sdhci.h > @@ -229,6 +229,8 @@ struct sdhci_ops { > void (*platform_send_init_74_clocks)(struct sdhci_host *host, > u8 power_mode); > unsigned int (*get_ro)(struct sdhci_host *host); > + unsigned int (*get_shared_pins)(struct sdhci_host *host); > + unsigned int (*put_shared_pins)(struct sdhci_host *host); > }; > > #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS > diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h > index 83bd9f7..32ab422 100644 > --- a/include/linux/mmc/sdhci.h > +++ b/include/linux/mmc/sdhci.h > @@ -85,6 +85,8 @@ struct sdhci_host { > #define SDHCI_QUIRK_NO_HISPD_BIT (1<<29) > /* Controller treats ADMA descriptors with length 0000h incorrectly */ > #define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC (1<<30) > +/* Controller shared data bus or other pins with other controllers */ > +#define SDHCI_QUIRK_SHARED_PINS (1<<31) > > int irq; /* Device IRQ */ > void __iomem *ioaddr; /* Mapped address */ > -- > 1.7.1 > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index f31077d..7b07152 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1379,6 +1379,13 @@ static void sdhci_tasklet_finish(unsigned long param) sdhci_reset(host, SDHCI_RESET_DATA); } + /* + * some controllers share data bus or other pins between multi-controller + * and need to switch the function of pins runtime + */ + if (host->quirks & SDHCI_QUIRK_SHARED_PINS) + host->ops->get_shared_pins(host); + host->mrq = NULL; host->cmd = NULL; host->data = NULL; @@ -1391,6 +1398,12 @@ static void sdhci_tasklet_finish(unsigned long param) spin_unlock_irqrestore(&host->lock, flags); mmc_request_done(host->mmc, mrq); + + /* + * release shared pins so that other controllers can use them + */ + if (host->quirks & SDHCI_QUIRK_SHARED_PINS) + host->ops->get_shared_pins(host); } static void sdhci_timeout_timer(unsigned long data) diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 85750a9..9d918a5 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -229,6 +229,8 @@ struct sdhci_ops { void (*platform_send_init_74_clocks)(struct sdhci_host *host, u8 power_mode); unsigned int (*get_ro)(struct sdhci_host *host); + unsigned int (*get_shared_pins)(struct sdhci_host *host); + unsigned int (*put_shared_pins)(struct sdhci_host *host); }; #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index 83bd9f7..32ab422 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -85,6 +85,8 @@ struct sdhci_host { #define SDHCI_QUIRK_NO_HISPD_BIT (1<<29) /* Controller treats ADMA descriptors with length 0000h incorrectly */ #define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC (1<<30) +/* Controller shared data bus or other pins with other controllers */ +#define SDHCI_QUIRK_SHARED_PINS (1<<31) int irq; /* Device IRQ */ void __iomem *ioaddr; /* Mapped address */