nand_spl: update udelay for Freescale boards

Let's use the more appropriate udelay for the nand_spl. While we
can't make use of u-boot's full udelay we can atl east use a for
loop that won't get optimized away .Since we have the bus clock
we can use the timebase to calculate wall time.

Looked at reusing the u-boot udelay functions but it pulls in a lot
of code and would require quite a bit of work to keep us within the
very small space constrains we currently have

Signed-off-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/nand_spl/board/freescale/common.c b/nand_spl/board/freescale/common.c
new file mode 100644
index 0000000000..0e099bc7c6
--- /dev/null
+++ b/nand_spl/board/freescale/common.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Author: Matthew McClintock <msm@freescale.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <asm/processor.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifndef CONFIG_SYS_FSL_TBCLK_DIV
+#define CONFIG_SYS_FSL_TBCLK_DIV 8
+#endif
+
+void udelay(unsigned long usec)
+{
+	u32 ticks_per_usec = gd->bus_clk / (CONFIG_SYS_FSL_TBCLK_DIV * 1000000);
+	u32 ticks = ticks_per_usec * usec;
+	u32 s = mfspr(SPRN_TBRL);
+
+	while ((mfspr(SPRN_TBRL) - s) < ticks);
+}