u-boot/nand_spl/board/freescale/common.c
Matthew McClintock 8c454047fe 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>
2012-08-23 10:24:17 -05:00

40 lines
1.2 KiB
C

/*
* 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);
}