linux/arch/mips/alchemy/common/clocks.c

94 lines
2.8 KiB
C

/*
* BRIEF MODULE DESCRIPTION
* Simple Au1xx0 clocks routines.
*
* Copyright 2001, 2008 MontaVista Software Inc.
* Author: MontaVista Software, Inc. <source@mvista.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 SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <asm/mach-au1x00/au1000.h>
static unsigned int au1x00_clock; /* Hz */
static unsigned int lcd_clock; /* KHz */
static unsigned long uart_baud_base;
/*
* Set the au1000_clock
*/
void set_au1x00_speed(unsigned int new_freq)
{
au1x00_clock = new_freq;
}
unsigned int get_au1x00_speed(void)
{
return au1x00_clock;
}
EXPORT_SYMBOL(get_au1x00_speed);
/*
* The UART baud base is not known at compile time ... if
* we want to be able to use the same code on different
* speed CPUs.
*/
unsigned long get_au1x00_uart_baud_base(void)
{
return uart_baud_base;
}
void set_au1x00_uart_baud_base(unsigned long new_baud_base)
{
uart_baud_base = new_baud_base;
}
/*
* Calculate the Au1x00's LCD clock based on the current
* cpu clock and the system bus clock, and try to keep it
* below 40 MHz (the Pb1000 board can lock-up if the LCD
* clock is over 40 MHz).
*/
void set_au1x00_lcd_clock(void)
{
unsigned int static_cfg0;
unsigned int sys_busclk = (get_au1x00_speed() / 1000) /
((int)(au_readl(SYS_POWERCTRL) & 0x03) + 2);
static_cfg0 = au_readl(MEM_STCFG0);
if (static_cfg0 & (1 << 11))
lcd_clock = sys_busclk / 5; /* note: BCLK switching fails with D5 */
else
lcd_clock = sys_busclk / 4;
if (lcd_clock > 50000) /* Epson MAX */
printk(KERN_WARNING "warning: LCD clock too high (%u KHz)\n",
lcd_clock);
}
unsigned int get_au1x00_lcd_clock(void)
{
return lcd_clock;
}
EXPORT_SYMBOL(get_au1x00_lcd_clock);