i2c: designware: Enable fast mode plus

This patch enabled fast mode plus. The fast mode plus and fast speed
share the same HCNT and LCNT register. So, the fast mode plus will only
run when the HCNT and LCNT value is provided. Else, it will run at fast
speed as default.

Signed-off-by: Weifeng Voon <weifeng.voon@intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index c6922b8..07edff7 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -347,8 +347,11 @@
 	dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
 	dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
-	/* Set SCL timing parameters for fast-mode */
-	if (dev->fs_hcnt && dev->fs_lcnt) {
+	/* Set SCL timing parameters for fast-mode or fast-mode plus */
+	if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
+		hcnt = dev->fp_hcnt;
+		lcnt = dev->fp_lcnt;
+	} else if (dev->fs_hcnt && dev->fs_lcnt) {
 		hcnt = dev->fs_hcnt;
 		lcnt = dev->fs_lcnt;
 	} else {