From: Chin Liang See <clsee@altera.com>
Date: Tue, 10 Jun 2014 06:26:52 +0000 (-0500)
Subject: mmc/dw_mmc: Fix clock divider calculation error for bypass mode
X-Git-Tag: v2014.10-rc1~14
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-uboot.git;a=commitdiff_plain;h=6ace153d130f528b88117b1edcfe017ea1852d67

mmc/dw_mmc: Fix clock divider calculation error for bypass mode

To fix the clock divider calculation error when the controller
clock same as the operating frequency. This is known as bypass
mode. In this mode, the divider should be 0.

Signed-off-by: Chin Liang See <clsee@altera.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Mischa Jonker <mjonker@synopsys.com>
---

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 5bf36a0309..0df30bc045 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -245,7 +245,10 @@ static int dwmci_setup_bus(struct dwmci_host *host, u32 freq)
 		return -EINVAL;
 	}
 
-	div = DIV_ROUND_UP(sclk, 2 * freq);
+	if (sclk == freq)
+		div = 0;	/* bypass mode */
+	else
+		div = DIV_ROUND_UP(sclk, 2 * freq);
 
 	dwmci_writel(host, DWMCI_CLKENA, 0);
 	dwmci_writel(host, DWMCI_CLKSRC, 0);