1 /*
2 * BRIEF MODULE DESCRIPTION
3 * Simple Au1000 clocks routines.
4 *
5 * Copyright 2001 MontaVista Software Inc.
6 * Author: MontaVista Software, Inc.
7 * ppopov@mvista.com or source@mvista.com
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
16 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
17 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
20 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
21 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * You should have received a copy of the GNU General Public License along
26 * with this program; if not, write to the Free Software Foundation, Inc.,
27 * 675 Mass Ave, Cambridge, MA 02139, USA.
28 */
29
30 #include <linux/module.h>
31 #include <asm/au1000.h>
32
33 static unsigned int au1x00_clock; // Hz
34 static unsigned int lcd_clock; // KHz
35 static unsigned long uart_baud_base;
36
37 /*
38 * Set the au1000_clock
39 */
set_au1x00_speed(unsigned int new_freq)40 void set_au1x00_speed(unsigned int new_freq)
41 {
42 au1x00_clock = new_freq;
43 }
44
get_au1x00_speed(void)45 unsigned int get_au1x00_speed(void)
46 {
47 return au1x00_clock;
48 }
49
50
51
52 /*
53 * The UART baud base is not known at compile time ... if
54 * we want to be able to use the same code on different
55 * speed CPUs.
56 */
get_au1x00_uart_baud_base(void)57 unsigned long get_au1x00_uart_baud_base(void)
58 {
59 return uart_baud_base;
60 }
61
set_au1x00_uart_baud_base(unsigned long new_baud_base)62 void set_au1x00_uart_baud_base(unsigned long new_baud_base)
63 {
64 uart_baud_base = new_baud_base;
65 }
66
67 /*
68 * Calculate the Au1x00's LCD clock based on the current
69 * cpu clock and the system bus clock, and try to keep it
70 * below 40 MHz (the Pb1000 board can lock-up if the LCD
71 * clock is over 40 MHz).
72 */
set_au1x00_lcd_clock(void)73 void set_au1x00_lcd_clock(void)
74 {
75 unsigned int static_cfg0;
76 unsigned int sys_busclk =
77 (get_au1x00_speed()/1000) /
78 ((int)(au_readl(SYS_POWERCTRL)&0x03) + 2);
79
80 static_cfg0 = au_readl(MEM_STCFG0);
81
82 if (static_cfg0 & (1<<11))
83 lcd_clock = sys_busclk / 5; /* note: BCLK switching fails with D5 */
84 else
85 lcd_clock = sys_busclk / 4;
86
87 if (lcd_clock > 50000) /* Epson MAX */
88 printk(__FUNCTION__
89 ": warning: LCD clock too high (%d KHz)\n",
90 lcd_clock);
91 }
92
get_au1x00_lcd_clock(void)93 unsigned int get_au1x00_lcd_clock(void)
94 {
95 return lcd_clock;
96 }
97
98 EXPORT_SYMBOL(get_au1x00_speed);
99 EXPORT_SYMBOL(get_au1x00_lcd_clock);
100