Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / arch / arm / plat-omap / sram-fn.S
1 /*
2  * linux/arch/arm/plat-omap/sram.S
3  *
4  * Functions that need to be run in internal SRAM
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #include <linux/config.h>
12 #include <linux/linkage.h>
13 #include <asm/assembler.h>
14 #include <asm/arch/io.h>
15 #include <asm/arch/hardware.h>
16
17         .text
18
19 /*
20  * Reprograms ULPD and CKCTL.
21  */
22 ENTRY(sram_reprogram_clock)
23         stmfd   sp!, {r0 - r12, lr}             @ save registers on stack
24
25         mov     r2, #IO_ADDRESS(DPLL_CTL) & 0xff000000
26         orr     r2, r2, #IO_ADDRESS(DPLL_CTL) & 0x00ff0000
27         orr     r2, r2, #IO_ADDRESS(DPLL_CTL) & 0x0000ff00
28
29         mov     r3, #IO_ADDRESS(ARM_CKCTL) & 0xff000000
30         orr     r3, r3, #IO_ADDRESS(ARM_CKCTL) & 0x00ff0000
31         orr     r3, r3, #IO_ADDRESS(ARM_CKCTL) & 0x0000ff00
32
33         tst     r0, #1 << 4                     @ want lock mode?
34         beq     newck                           @ nope
35         bic     r0, r0, #1 << 4                 @ else clear lock bit
36         strh    r0, [r2]                        @ set dpll into bypass mode
37         orr     r0, r0, #1 << 4                 @ set lock bit again
38
39 newck:
40         strh    r1, [r3]                        @ write new ckctl value
41         strh    r0, [r2]                        @ write new dpll value
42
43         mov     r4, #0x0700                     @ let the clocks settle
44         orr     r4, r4, #0x00ff
45 delay:  sub     r4, r4, #1
46         cmp     r4, #0
47         bne     delay
48
49 lock:   ldrh    r4, [r2], #0                    @ read back dpll value
50         tst     r0, #1 << 4                     @ want lock mode?
51         beq     out                             @ nope
52         tst     r4, #1 << 0                     @ dpll rate locked?
53         beq     lock                            @ try again
54
55 out:
56         ldmfd   sp!, {r0 - r12, pc}             @ restore regs and return
57 ENTRY(sram_reprogram_clock_sz)
58         .word   . - sram_reprogram_clock