diff options
Diffstat (limited to 'board/adsvix/pxavoltage.S')
| -rw-r--r-- | board/adsvix/pxavoltage.S | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/board/adsvix/pxavoltage.S b/board/adsvix/pxavoltage.S new file mode 100644 index 000000000..5a0359c36 --- /dev/null +++ b/board/adsvix/pxavoltage.S @@ -0,0 +1,231 @@ +/* + * (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 + |