[PATCH 3/5] mmc_sdhci: improve the wake-up support

Giuseppe CAVALLARO
2010-11-10T15:28:38Z

This patch reworks the wake-up support in the sdhci driver.
It is now able to wake-up the system on: Card interrupts,
Card insertion and Card removal events.
This has been tested on ST STB where can make sense to
wake-up the box as soon as a card is inserted.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
---
drivers/mmc/host/sdhci.c | 110 +++++++++++++++++++++++++++++++++++++++++-----
drivers/mmc/host/sdhci.h | 3 +-
include/linux/mmc/pm.h | 9 +++-
3 files changed, 109 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 69c80c9..8db9757 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -36,7 +36,8 @@
#define SDHCI_USE_LEDS_CLASS
#endif

-static unsigned int debug_quirks = 0;
+static unsigned int debug_quirks;
+static unsigned int wakeup;

static void sdhci_prepare_data(struct sdhci_host *, struct mmc_data *);
static void sdhci_finish_data(struct sdhci_host *);
@@ -1595,6 +1596,83 @@ 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);
+
+ /*
+ * If a wake up event is set by user, then force the pm_flags
+ * to use it (independently of the previous setting made in the d.d.
+ */
+ if (wakeup == 1)
+ host->mmc->pm_flags |= MMC_PM_WAKE_SDIO_IRQ;
+ else if (wakeup == 2)
+ host->mmc->pm_flags |= MMC_PM_WAKE_SDIO_CARD_INS;
+ else if (wakeup == 3)
+ host->mmc->pm_flags |= MMC_PM_WAKE_SDIO_CARD_REM;
+
+ /*
+ * 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 (host->mmc->pm_flags & MMC_PM_WAKE_SDIO_IRQ)
+ wakeflag |= SDHCI_WAKE_ON_INT;
+ if (host->mmc->pm_flags & MMC_PM_WAKE_SDIO_CARD_INS)
+ wakeflag |= SDHCI_WAKE_ON_INSERT;
+ if (host->mmc->pm_flags & MMC_PM_WAKE_SDIO_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;
@@ -1605,7 +1683,10 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
if (ret)
return ret;

- free_irq(host->irq, host);
+ if (host->mmc->pm_flags & MMC_PM_KEEP_POWER)
+ sdhci_set_wakeup(host);
+ else
+ free_irq(host->irq, host);

return 0;
}
@@ -1621,12 +1702,13 @@ 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;
-
- sdhci_init(host, (host->mmc->pm_flags & MMC_PM_KEEP_POWER));
+ if (!(host->mmc->pm_flags & MMC_PM_KEEP_POWER)) {
+ 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);
mmiowb();

ret = mmc_resume_host(host->mmc);
@@ -1637,16 +1719,16 @@ 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, unsigned 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);
}

EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);
-
#endif /* CONFIG_PM */

/*****************************************************************************\
@@ -1928,6 +2010,10 @@ int sdhci_add_host(struct sdhci_host *host)

sdhci_enable_card_detection(host);

+#ifdef CONFIG_PM
+ if (host->mmc->pm_flags & MMC_PM_KEEP_POWER)
+ sdhci_can_wakeup(host);
+#endif
return 0;

#ifdef SDHCI_USE_LEDS_CLASS
@@ -2021,9 +2107,11 @@ module_init(sdhci_drv_init);
module_exit(sdhci_drv_exit);

module_param(debug_quirks, uint, 0444);
+module_param(wakeup, uint, S_IRUGO | S_IWUSR);

MODULE_AUTHOR("Pierre Ossman <pierre@ossman.eu>");
MODULE_DESCRIPTION("Secure Digital Host Controller Interface core driver");
MODULE_LICENSE("GPL");

MODULE_PARM_DESC(debug_quirks, "Force certain quirks.");
+MODULE_PARM_DESC(wakeup, "Wakeup:0:disable,1:Card Int,2:Card Ins,3: Card Rem.");
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index f939371..cd70d00 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -312,7 +312,8 @@ 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,
+ unsigned int mode);
#endif

#endif /* __SDHCI_HW_H */
diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
index d37aac4..31df7f2 100644
--- a/include/linux/mmc/pm.h
+++ b/include/linux/mmc/pm.h
@@ -24,7 +24,14 @@

typedef unsigned int mmc_pm_flag_t;

-#define MMC_PM_KEEP_POWER (1 << 0) /* preserve card power during suspend */
+/* Preserve card power during suspend. It is also used for notifying
+ * that the device can wakeup the system. This can be done, for example,
+ * by either card interrupt enent or card insertion event or card
+ * removal event.
+ */
+#define MMC_PM_KEEP_POWER (1 << 0)
#define MMC_PM_WAKE_SDIO_IRQ (1 << 1) /* wake up host system on SDIO IRQ assertion */
+#define MMC_PM_WAKE_SDIO_CARD_INS (1 << 2) /* wake up on card insertion */
+#define MMC_PM_WAKE_SDIO_CARD_REM (1 << 3) /* wake up on card removal */

#endif
--
1.5.5.6