sdhci-of: fix high-speed cards recognition

eSDHC fails to recognize some SDHS cards, throwing timeout errors:

  mmc0: error -110 whilst initialising SD card

That's because we calculate timeout value in a wrong way: on eSDHC hosts
the timeout clock is derivied from the SD clock, which is set dynamically.

As David Vrabel suggested, deriving timeout clock from SD clock is a
common scheme, so let's implement DATA_TIMEOUT_USES_SDCLK quirk and use it
for eSDHC hosts.

Also, from now on we don't need esdhc_get_timeout_clock() callback, so
remove it.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: Ben Dooks <ben@fluff.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 7f7f45b..38a7874 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -591,6 +591,9 @@
 	target_timeout = data->timeout_ns / 1000 +
 		data->timeout_clks / host->clock;
 
+	if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
+		host->timeout_clk = host->clock / 1000;
+
 	/*
 	 * Figure out needed cycles.
 	 * We do this in steps in order to fit inside a 32 bit int.
@@ -1757,13 +1760,15 @@
 	host->timeout_clk =
 		(caps & SDHCI_TIMEOUT_CLK_MASK) >> SDHCI_TIMEOUT_CLK_SHIFT;
 	if (host->timeout_clk == 0) {
-		if (!host->ops->get_timeout_clock) {
+		if (host->ops->get_timeout_clock) {
+			host->timeout_clk = host->ops->get_timeout_clock(host);
+		} else if (!(host->quirks &
+				SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
 			printk(KERN_ERR
 			       "%s: Hardware doesn't specify timeout clock "
 			       "frequency.\n", mmc_hostname(mmc));
 			return -ENODEV;
 		}
-		host->timeout_clk = host->ops->get_timeout_clock(host);
 	}
 	if (caps & SDHCI_TIMEOUT_CLK_UNIT)
 		host->timeout_clk *= 1000;