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/*
* (C) Copyright 2004
* Robert Whaley, Applied Data Systems, Inc. rwhaley@applieddata.net
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <asm/arch/pxa-regs.h>
#define LTC1663_ADDR 0x20
#define LTC1663_SY 0x01 /* Sync ACK */
#define LTC1663_SD 0x04 /* shutdown */
#define LTC1663_BG 0x04 /* Internal Voltage Ref */
#define VOLT_1_55 18 /* DAC value for 1.55V */
.global initPXAvoltage
@ Set the voltage to 1.55V early in the boot process so we can run
@ at a high clock speed and boot quickly. Note that this is necessary
@ because the reset button does not reset the CPU voltage, so if the
@ voltage was low (say 0.85V) then the CPU would crash without this
@ routine
@ This routine clobbers r0-r4
initializei2c:
ldr r2, =CKEN
ldr r3, [r2]
orr r3, r3, #CKEN15_PWRI2C
str r3, [r2]
ldr r2, =PCFR
ldr r3, [r2]
orr r3, r3, #PCFR_PI2C_EN
str r3, [r2]
/* delay for about 250msec
*/
ldr r3, =OSCR
mov r2, #0
str r2, [r3]
ldr r1, =0xC0000
1:
ldr r2, [r3]
cmp r1, r2
bgt 1b
ldr r0, =PWRICR
ldr r1, [r0]
bic r1, r1, #(ICR_MA | ICR_START | ICR_STOP)
str r1, [r0]
orr r1, r1, #ICR_UR
str r1, [r0]
ldr r2, =PWRISR
ldr r3, =0x7ff
str r3, [r2]
bic r1, r1, #ICR_UR
str r1, [r0]
mov r1, #(ICR_GCD | ICR_SCLE)
str r1, [r0]
orr r1, r1, #ICR_IUE
str r1, [r0]
orr r1, r1, #ICR_FM
str r1, [r0]
/* delay for about 1msec
*/
ldr r3, =OSCR
mov r2, #0
str r2, [r3]
ldr r1, =0xC00
1:
ldr r2, [r3]
cmp r1, r2
bgt 1b
mov pc, lr
sendbytei2c:
ldr r3, =PWRIDBR
str r0, [r3]
ldr r3, =PWRICR
ldr r0, [r3]
orr r0, r0, r1
bic r0, r0, r2
str r0, [r3]
orr r0, r0, #ICR_TB
str r0, [r3]
mov r2, #0x100000
waitfortxemptyi2c:
ldr r0, =PWRISR
ldr r1, [r0]
/* take it from the top if we don't get empty after a while */
subs r2, r2, #1
moveq lr, r4
beq initPXAvoltage
tst r1, #ISR_ITE
beq waitfortxemptyi2c
orr r1, r1, #ISR_ITE
str r1, [r0]
mov pc, lr
initPXAvoltage:
mov r4, lr
bl setleds
bl initializei2c
bl setleds
/* now send the real message to set the correct voltage */
ldr r0, =LTC1663_ADDR
mov r0, r0, LSL #1
mov r1, #ICR_START
ldr r2, =(ICR_STOP | ICR_ALDIE | ICR_ACKNAK)
bl sendbytei2c
bl setleds
mov r0, #LTC1663_BG
mov r1, #0
mov r2, #(ICR_STOP | ICR_START)
bl sendbytei2c
bl setleds
ldr r0, =VOLT_1_55
and r0, r0, #0xff
mov r1, #0
mov r2, #(ICR_STOP | ICR_START)
bl sendbytei2c
bl setleds
ldr r0, =VOLT_1_55
mov r0, r0, ASR #8
and r0, r0, #0xff
mov r1, #ICR_STOP
mov r2, #ICR_START
bl sendbytei2c
bl setleds
@ delay a little for the volatage to stablize
ldr r3, =OSCR
mov r2, #0
str r2, [r3]
ldr r1, =0xC0
1:
ldr r2, [r3]
cmp r1, r2
bgt 1b
mov pc, r4
setleds:
mov pc, lr
ldr r5, =0x40e00058
ldr r3, [r5]
bic r3, r3, #0x3
str r3, [r5]
ldr r5, =0x40e0000c
ldr r3, [r5]
orr r3, r3, #0x00010000
str r3, [r5]
@ inner loop
mov r0, #0x2
1:
ldr r5, =0x40e00018
mov r3, #0x00010000
str r3, [r5]
@ outer loop
mov r3, #0x00F00000
2:
subs r3, r3, #1
bne 2b
ldr r5, =0x40e00024
mov r3, #0x00010000
str r3, [r5]
@ outer loop
mov r3, #0x00F00000
3:
subs r3, r3, #1
bne 3b
subs r0, r0, #1
bne 1b
mov pc, lr
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