rockbox/firmware/target/arm/tms320dm320/sansa-connect/crt0-board.S
Tomasz Moń 8de163b8ae
Sansa Connect: Fix reported CPU frequency
Make frequency related comments accurate. Disable UART0 clock.

Change-Id: I224a3d6656ad53165dcff68ed716fa2c6863240d
2021-07-09 14:16:05 +02:00

258 lines
6 KiB
ArmAsm

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id: $
*
* Copyright (C) 2011 by Tomasz Moń
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
/* Macro for reading a register */
.macro mrh register
ldr r1, =\register
ldrh r0, [r1]
.endm
/* Macro for writing a register */
.macro mwh register, value
ldr r0, =\value
ldr r1, =\register
strh r0, [r1]
.endm
/* This version uses a mov to save on the literal pool size. Otherwise it is
* functionally equivalent.
*/
.macro mwhm register, value
mov r0, #\value
ldr r1, =\register
strh r0, [r1]
.endm
/*
* _init_board:
* This function initializes the specific board this SoC is on.
*/
.section .init, "ax"
.code 32
.align 0x04
.global _init_board
.type _init_board, %function
_init_board:
/* Setup the EMIF interface timings */
/* FLASH interface:
* These are based on the OF setup
*/
/* IO_EMIF_CS0CTRL1 and
* IO_EMIF_CS0CTRL2
*/
mwh 0x30A00, 0x889A
mwh 0x30A02, 0x1110
mwhm 0x30A04, 0
mwh 0x30A06, 0x1415
mwh 0x30A08, 0x1109
mwh 0x30A0A, 0x1220
mwh 0x30A0C, 0x1104
mwh 0x30A0E, 0x0222
/* IO_EMIF_CS3CTRL1 and
* IO_EMIF_CS3CTRL2
*/
mwh 0x30A10, 0x8899
mwh 0x30A12, 0x5110
/* USB interface */
/* IO_EMIF_CS4CTRL1 and
* IO_EMIF_CS4CTRL2
*/
mwh 0x30A14, 0x77DF
mwh 0x30A16, 0x7740
/* IO_EMIF_BUSCTRL */
mwhm 0x30A18, 0
mwhm 0x30A1A, 0
mwhm 0x30A1C, 0
mwhm 0x30A1E, 0
_clock_setup:
/* Clock initialization */
/* Disable peripheral clocks */
mwhm 0x3089A, 0
mwhm 0x3089C, 0
/* IO_CLK_BYP: Bypass the PLLs for the following changes */
mwh 0x30894, 0x1111
/*
* IO_CLK_PLLA: 27 MHz * 11 / 1 = 297 MHz
* IO_CLK_PLLB: 27 MHz
*/
mwh 0x30880, 0x10A0
mwhm 0x30882, 0x1000
/* IO_CLK_SEL0: Timer 0 and 1, UART 0 and 1 from PLLIN (27 MHz) */
mwh 0x30884, 0x0066
/* IO_CLK_SEL1: VENC from PLLA, OSD clock = VENC clock / 2 */
mwhm 0x30886, 0x0003
/* IO_CLK_SEL2: ARM, AXL, SDRAM and DSP are from PLLA */
mwh 0x30888, 0
/* IO_CLK_DIV0: Set the fast clock speed for the ARM/AHB
* ARM = PLLA / 2 = 148.5 MHz
* AHB = ARM / 2 = 74.25 MHz
*/
mwh 0x3088A, 0x0101
/* IO_CLK_DIV1: Accelerator, SDRAM
* AXL = PLLA / 2 = 148.5 MHz
* SDRAM = PLLA / 3 = 99 MHz
*/
mwh 0x3088C, 0x0102
/* IO_CLK_DIV2: DSP, MS Clock
* OF must be booted with this value
* DSP = PLLA / 3 = 99 MHz
* MS = PLLA / 1 = 297 MHz
*/
mwhm 0x3088E, 0x0200
/* PLLA &= ~0x1000 (BIC #0x1000) */
mrh 0x30880
bic r0, r0, #0x1000
strh r0, [r1]
/* Wait for PLLs to lock before feeding them to the downstream devices */
_plla_wait:
mrh 0x30880
bic r0, r0, #0x7F
tst r0, r0
beq _plla_wait
/* IO_CLK_BYP: Enable PLL feeds */
mwhm 0x30894, 0x0
/* IO_CLK_MOD0
* Enable clocks:
* ARM, Bus Controller, AHB, ARM internal memory, EMIF, SDRAM
* Disable clocks:
* ETM, E2ICE, INTC, EXTHOST, DSP, HPIB
*/
mwh 0x30898, 0x01A7
/* IO_CLK_MOD2: Enable GIO and SIF1 clocks */
mwhm 0x3089C, 0x0420
/* Setup the SDRAM range on the AHB bus */
/* SDRAMSA */
mov r0, #0x60000
mov r1, #0x1000000
str r1, [r0, #0xF00]
/* SDRAMEA: 64MB */
mov r1, #0x5000000
str r1, [r0, #0xF04]
/* SDRC_REFCTL */
mwh 0x309A8, 0
ldr r0, =0x309A6
mov r2, #0x1380
orr r1, r2, #2
strh r1, [r0]
orr r1, r2, #4
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
strh r1, [r0]
orr r1, r2, #1
strh r1, [r0]
strh r2, [r0]
strh r2, [r0]
mwhm 0x309A8, 0x0140
/* IMGBUF SDRAM priority bit 2 set */
mwhm 0x309BE, 0x4
/* SDRAM refresh priority bit 1 set */
mwhm 0x309BC, 0x2
/* Use defined priority bits */
ldr r0, =0x309C4
ldr r1, [r0]
orr r1, r1, #1
strh r1, [r0]
ldr r0, =0x309A6
mov r1, #0x1380
strh r1, [r0]
bic r1, r1, #0x80
strh r1, [r0]
orr r1, r1, #0x40
strh r1, [r0]
/* Enable auto refresh with interval (64 + 1) * 8 SDRAM clocks */
mwhm 0x309A8, 0x0140
/* Go through the GPIO initialization */
/* Warning: setting some of the functions wrong will make OF unable
to boot (freeze during startup) */
/* IO_GIO_FSEL0: Set up the GPIO pin functions 0-16 */
mwhm 0x305A4, 0xC000
/* IO_GIO_FSEL1: 17-24 */
mwh 0x305A6, 0xAAAA
/* IO_GIO_FSEL2: 18-32 */
mwh 0x305A8, 0xA80A
/* IO_GIO_FSEL3: 33-40 */
mwh 0x305AA, 0x1007
/* IO_GIO_DIR0 */
mwh 0x30580, 0xFF77
/* IO_GIO_DIR1 */
mwh 0x30582, 0xEFFE
/* IO_GIO_DIR2 */
mwh 0x30584, 0x01FD
/* IO_GIO_INV0 */
mwh 0x30586, 0x0000
/* IO_GIO_INV1 */
mwh 0x30588, 0x0000
/* IO_GIO_INV2 */
mwh 0x3058A, 0x0000
bx lr
.ltorg
.size _init_board, .-_init_board