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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 000000000000..043429d17c5f --- /dev/null +++ b/arch/mips/alchemy/common/clocks.c | |||
@@ -0,0 +1,93 @@ | |||
1 | /* | ||
2 | * BRIEF MODULE DESCRIPTION | ||
3 | * Simple Au1xx0 clocks routines. | ||
4 | * | ||
5 | * Copyright 2001, 2008 MontaVista Software Inc. | ||
6 | * Author: MontaVista Software, Inc. <source@mvista.com> | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify it | ||
9 | * under the terms of the GNU General Public License as published by the | ||
10 | * Free Software Foundation; either version 2 of the License, or (at your | ||
11 | * option) any later version. | ||
12 | * | ||
13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED | ||
14 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | ||
15 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN | ||
16 | * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | ||
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | ||
19 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON | ||
20 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | ||
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
23 | * | ||
24 | * You should have received a copy of the GNU General Public License along | ||
25 | * with this program; if not, write to the Free Software Foundation, Inc., | ||
26 | * 675 Mass Ave, Cambridge, MA 02139, USA. | ||
27 | */ | ||
28 | |||
29 | #include <linux/module.h> | ||
30 | #include <asm/mach-au1x00/au1000.h> | ||
31 | |||
32 | static unsigned int au1x00_clock; /* Hz */ | ||
33 | static unsigned int lcd_clock; /* KHz */ | ||
34 | static unsigned long uart_baud_base; | ||
35 | |||
36 | /* | ||
37 | * Set the au1000_clock | ||
38 | */ | ||
39 | void set_au1x00_speed(unsigned int new_freq) | ||
40 | { | ||
41 | au1x00_clock = new_freq; | ||
42 | } | ||
43 | |||
44 | unsigned int get_au1x00_speed(void) | ||
45 | { | ||
46 | return au1x00_clock; | ||
47 | } | ||
48 | EXPORT_SYMBOL(get_au1x00_speed); | ||
49 | |||
50 | /* | ||
51 | * The UART baud base is not known at compile time ... if | ||
52 | * we want to be able to use the same code on different | ||
53 | * speed CPUs. | ||
54 | */ | ||
55 | unsigned long get_au1x00_uart_baud_base(void) | ||
56 | { | ||
57 | return uart_baud_base; | ||
58 | } | ||
59 | |||
60 | void set_au1x00_uart_baud_base(unsigned long new_baud_base) | ||
61 | { | ||
62 | uart_baud_base = new_baud_base; | ||
63 | } | ||
64 | |||
65 | /* | ||
66 | * Calculate the Au1x00's LCD clock based on the current | ||
67 | * cpu clock and the system bus clock, and try to keep it | ||
68 | * below 40 MHz (the Pb1000 board can lock-up if the LCD | ||
69 | * clock is over 40 MHz). | ||
70 | */ | ||
71 | void set_au1x00_lcd_clock(void) | ||
72 | { | ||
73 | unsigned int static_cfg0; | ||
74 | unsigned int sys_busclk = (get_au1x00_speed() / 1000) / | ||
75 | ((int)(au_readl(SYS_POWERCTRL) & 0x03) + 2); | ||
76 | |||
77 | static_cfg0 = au_readl(MEM_STCFG0); | ||
78 | |||
79 | if (static_cfg0 & (1 << 11)) | ||
80 | lcd_clock = sys_busclk / 5; /* note: BCLK switching fails with D5 */ | ||
81 | else | ||
82 | lcd_clock = sys_busclk / 4; | ||
83 | |||
84 | if (lcd_clock > 50000) /* Epson MAX */ | ||
85 | printk(KERN_WARNING "warning: LCD clock too high (%u KHz)\n", | ||
86 | lcd_clock); | ||
87 | } | ||
88 | |||
89 | unsigned int get_au1x00_lcd_clock(void) | ||
90 | { | ||
91 | return lcd_clock; | ||
92 | } | ||
93 | EXPORT_SYMBOL(get_au1x00_lcd_clock); | ||