sdhci: Add set_clock callback and a quirk for nonstandard clocks

FSL eSDHC hosts have incompatible register map to manage the SDCLK.
This patch adds set_clock callback so that drivers could overwrite
set_clock behaviour.

Similar patch[1] was posted by Ben Dooks, though in Ben's version the
callback is named change_clock, plus the patch has some unrelated bits
that makes the patch difficult to reuse.

[1] http://lkml.org/lkml/2008/12/2/160

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 34ab77bd12ae..75d0ecbce10c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -949,6 +949,12 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
         if (clock == host->clock)
                 return;
 
+        if (host->ops->set_clock) {
+                host->ops->set_clock(host, clock);
+                if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
+                        return;
+        }
+
         sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
 
         if (clock == 0)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index aab0652a4585..b9bc622735ba 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -218,6 +218,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK_BROKEN_CARD_DETECTION               (1<<15)
 /* Controller reports inverted write-protect state */
 #define SDHCI_QUIRK_INVERTED_WRITE_PROTECT              (1<<16)
+/* Controller has nonstandard clock management */
+#define SDHCI_QUIRK_NONSTANDARD_CLOCK                   (1<<17)
 
         int                     irq;            /* Device IRQ */
         void __iomem *          ioaddr;         /* Mapped address */
@@ -284,6 +286,8 @@ struct sdhci_ops {
         void            (*writeb)(struct sdhci_host *host, u8 val, int reg);
 #endif
 
+        void    (*set_clock)(struct sdhci_host *host, unsigned int clock);
+
         int             (*enable_dma)(struct sdhci_host *host);
         unsigned int    (*get_max_clock)(struct sdhci_host *host);
         unsigned int    (*get_timeout_clock)(struct sdhci_host *host);