| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/mach-au1x00/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 | */ |
| 40 | void set_au1x00_speed(unsigned int new_freq) |
| 41 | { |
| 42 | au1x00_clock = new_freq; |
| 43 | } |
| 44 | |
| 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 | */ |
| 57 | unsigned long get_au1x00_uart_baud_base(void) |
| 58 | { |
| 59 | return uart_baud_base; |
| 60 | } |
| 61 | |
| 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 | */ |
| 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("warning: LCD clock too high (%d KHz)\n", lcd_clock); |
| 89 | } |
| 90 | |
| 91 | unsigned int get_au1x00_lcd_clock(void) |
| 92 | { |
| 93 | return lcd_clock; |
| 94 | } |
| 95 | |
| 96 | EXPORT_SYMBOL(get_au1x00_lcd_clock); |