mmc: host: omap_hsmmc: avoid possible overflow of timeout value

commit a53210f5 upstream.

Fixes: a45c6cb8 ("[ARM] 5369/1: omap mmc: Add new omap
hsmmc controller for 2430 and 34xx, v3")

when using really large timeout (up to 4*60*1000 ms for bkops)
there is a possibility of data overflow using
unsigned int so use 64 bit unsigned long long.
Signed-off-by: Ravikumar Kattekola <rk@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[bwh: Backported to 3.2:
 - Drop change in omap_hsmmc_prepare_data()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/mmc/host/omap_hsmmc.c

@@ -1499,10 +1499,11 @@ static int omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host,
 }
 
 static void set_data_timeout(struct omap_hsmmc_host *host,
-			     unsigned int timeout_ns,
+			     unsigned long long timeout_ns,
 			     unsigned int timeout_clks)
 {
-	unsigned int timeout, cycle_ns;
+	unsigned long long timeout = timeout_ns;
+	unsigned int cycle_ns;
 	uint32_t reg, clkd, dto = 0;
 
 	reg = OMAP_HSMMC_READ(host->base, SYSCTL);
@@ -1511,7 +1512,7 @@ static void set_data_timeout(struct omap_hsmmc_host *host,
 		clkd = 1;
 
 	cycle_ns = 1000000000 / (clk_get_rate(host->fclk) / clkd);
-	timeout = timeout_ns / cycle_ns;
+	do_div(timeout, cycle_ns);
 	timeout += timeout_clks;
 	if (timeout) {
 		while ((timeout & 0x80000000) == 0) {