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Diffstat (limited to 'arch/mips/alchemy/common/clocks.c')
-rw-r--r-- | arch/mips/alchemy/common/clocks.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/mips/alchemy/common/clocks.c b/arch/mips/alchemy/common/clocks.c new file mode 100644 index 00000000000..043429d17c5 --- /dev/null +++ b/arch/mips/alchemy/common/clocks.c @@ -0,0 +1,93 @@ +/* + * 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); |