u-boot/arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S
Sergey Kostanbaev 7237d22baa arm: ep9315: Return back Cirrus Logic EDB9315A board support
This patch returns back support for old ep93xx processors family

Signed-off-by: Sergey Kostanbaev <sergey.kostanbaev@gmail.com>
Cc: albert.u.boot@aribaud.net
2014-07-04 23:45:48 +02:00

458 lines
10 KiB
ArmAsm

/*
* Low-level initialization for EP93xx
*
* Copyright (C) 2009 Matthias Kaehlcke <matthias@kaehlcke.net>
* Copyright (C) 2013
* Sergey Kostanabev <sergey.kostanbaev <at> fairwaves.ru>
*
* Copyright (C) 2006 Dominic Rath <Dominic.Rath@gmx.de>
* Copyright (C) 2006 Cirrus Logic Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <asm/arch-ep93xx/ep93xx.h>
/*
/* Configure the SDRAM based on the supplied settings.
*
* Input: r0 - SDRAM DEVCFG register
* r2 - configuration for SDRAM chips
* Output: none
* Modifies: r3, r4
*/
ep93xx_sdram_config:
/* Program the SDRAM device configuration register. */
ldr r3, =SDRAM_BASE
#ifdef CONFIG_EDB93XX_SDCS0
str r0, [r3, #SDRAM_OFF_DEVCFG0]
#endif
#ifdef CONFIG_EDB93XX_SDCS1
str r0, [r3, #SDRAM_OFF_DEVCFG1]
#endif
#ifdef CONFIG_EDB93XX_SDCS2
str r0, [r3, #SDRAM_OFF_DEVCFG2]
#endif
#ifdef CONFIG_EDB93XX_SDCS3
str r0, [r3, #SDRAM_OFF_DEVCFG3]
#endif
/* Set the Initialize and MRS bits (issue continuous NOP commands
* (INIT & MRS set))
*/
ldr r4, =(EP93XX_SDRAMCTRL_GLOBALCFG_INIT | \
EP93XX_SDRAMCTRL_GLOBALCFG_MRS | \
EP93XX_SDRAMCTRL_GLOBALCFG_CKE)
str r4, [r3, #SDRAM_OFF_GLCONFIG]
/* Delay for 200us. */
mov r4, #0x3000
delay1:
subs r4, r4, #1
bne delay1
/* Clear the MRS bit to issue a precharge all. */
ldr r4, =(EP93XX_SDRAMCTRL_GLOBALCFG_INIT | \
EP93XX_SDRAMCTRL_GLOBALCFG_CKE)
str r4, [r3, #SDRAM_OFF_GLCONFIG]
/* Temporarily set the refresh timer to 0x10. Make it really low so
* that refresh cycles are generated.
*/
ldr r4, =0x10
str r4, [r3, #SDRAM_OFF_REFRSHTIMR]
/* Delay for at least 80 SDRAM clock cycles. */
mov r4, #80
delay2:
subs r4, r4, #1
bne delay2
/* Set the refresh timer to the fastest required for any device
* that might be used. Set 9.6 ms refresh time.
*/
ldr r4, =0x01e0
str r4, [r3, #SDRAM_OFF_REFRSHTIMR]
/* Select mode register update mode. */
ldr r4, =(EP93XX_SDRAMCTRL_GLOBALCFG_CKE | \
EP93XX_SDRAMCTRL_GLOBALCFG_MRS)
str r4, [r3, #SDRAM_OFF_GLCONFIG]
/* Program the mode register on the SDRAM by performing fake read */
ldr r4, [r2]
/* Select normal operating mode. */
ldr r4, =EP93XX_SDRAMCTRL_GLOBALCFG_CKE
str r4, [r3, #SDRAM_OFF_GLCONFIG]
/* Return to the caller. */
mov pc, lr
/*
* Test to see if the SDRAM has been configured in a usable mode.
*
* Input: r0 - Test address of SDRAM
* Output: r0 - 0 -- Test OK, -1 -- Failed
* Modifies: r0-r5
*/
ep93xx_sdram_test:
/* Load the test patterns to be written to SDRAM. */
ldr r1, =0xf00dface
ldr r2, =0xdeadbeef
ldr r3, =0x08675309
ldr r4, =0xdeafc0ed
/* Store the test patterns to SDRAM. */
stmia r0, {r1-r4}
/* Load the test patterns from SDRAM one at a time and compare them
* to the actual pattern.
*/
ldr r5, [r0]
cmp r5, r1
ldreq r5, [r0, #0x0004]
cmpeq r5, r2
ldreq r5, [r0, #0x0008]
cmpeq r5, r3
ldreq r5, [r0, #0x000c]
cmpeq r5, r4
/* Return -1 if a mismatch was encountered, 0 otherwise. */
mvnne r0, #0xffffffff
moveq r0, #0x00000000
/* Return to the caller. */
mov pc, lr
/*
* Determine the size of the SDRAM. Use data=address for the scan.
*
* Input: r0 - Start SDRAM address
* Return: r0 - Single block size
* r1 - Valid block mask
* r2 - Total block count
* Modifies: r0-r5
*/
ep93xx_sdram_size:
/* Store zero at offset zero. */
str r0, [r0]
/* Start checking for an alias at 1MB into SDRAM. */
ldr r1, =0x00100000
/* Store the offset at the current offset. */
check_block_size:
str r1, [r0, r1]
/* Read back from zero. */
ldr r2, [r0]
/* Stop searching of an alias was found. */
cmp r1, r2
beq found_block_size
/* Advance to the next power of two boundary. */
mov r1, r1, lsl #1
/* Loop back if the size has not reached 256MB. */
cmp r1, #0x10000000
bne check_block_size
/* A full 256MB of memory was found, so return it now. */
ldr r0, =0x10000000
ldr r1, =0x00000000
ldr r2, =0x00000001
mov pc, lr
/* An alias was found. See if the first block is 128MB in size. */
found_block_size:
cmp r1, #0x08000000
/* The first block is 128MB, so there is no further memory. Return it
* now.
*/
ldreq r0, =0x08000000
ldreq r1, =0x00000000
ldreq r2, =0x00000001
moveq pc, lr
/* Save the block size, set the block address bits to zero, and
* initialize the block count to one.
*/
mov r3, r1
ldr r4, =0x00000000
ldr r5, =0x00000001
/* Look for additional blocks of memory by searching for non-aliases. */
find_blocks:
/* Store zero back to address zero. It may be overwritten. */
str r0, [r0]
/* Advance to the next power of two boundary. */
mov r1, r1, lsl #1
/* Store the offset at the current offset. */
str r1, [r0, r1]
/* Read back from zero. */
ldr r2, [r0]
/* See if a non-alias was found. */
cmp r1, r2
/* If a non-alias was found, then or in the block address bit and
* multiply the block count by two (since there are two unique
* blocks, one with this bit zero and one with it one).
*/
orrne r4, r4, r1
movne r5, r5, lsl #1
/* Continue searching if there are more address bits to check. */
cmp r1, #0x08000000
bne find_blocks
/* Return the block size, address mask, and count. */
mov r0, r3
mov r1, r4
mov r2, r5
/* Return to the caller. */
mov pc, lr
.globl lowlevel_init
lowlevel_init:
mov r6, lr
/* Make sure caches are off and invalidated. */
ldr r0, =0x00000000
mcr p15, 0, r0, c1, c0, 0
nop
nop
nop
nop
nop
/* Turn off the green LED and turn on the red LED. If the red LED
* is left on for too long, the external reset circuit described
* by application note AN258 will cause the system to reset.
*/
ldr r1, =EP93XX_LED_DATA
ldr r0, [r1]
bic r0, r0, #EP93XX_LED_GREEN_ON
orr r0, r0, #EP93XX_LED_RED_ON
str r0, [r1]
/* Undo the silly static memory controller programming performed
* by the boot rom.
*/
ldr r0, =SMC_BASE
/* Set WST1 and WST2 to 31 HCLK cycles (slowest access) */
ldr r1, =0x0000fbe0
/* Reset EP93XX_OFF_SMCBCR0 */
ldr r2, [r0]
orr r2, r2, r1
str r2, [r0]
ldr r2, [r0, #EP93XX_OFF_SMCBCR1]
orr r2, r2, r1
str r2, [r0, #EP93XX_OFF_SMCBCR1]
ldr r2, [r0, #EP93XX_OFF_SMCBCR2]
orr r2, r2, r1
str r2, [r0, #EP93XX_OFF_SMCBCR2]
ldr r2, [r0, #EP93XX_OFF_SMCBCR3]
orr r2, r2, r1
str r2, [r0, #EP93XX_OFF_SMCBCR3]
ldr r2, [r0, #EP93XX_OFF_SMCBCR6]
orr r2, r2, r1
str r2, [r0, #EP93XX_OFF_SMCBCR6]
ldr r2, [r0, #EP93XX_OFF_SMCBCR7]
orr r2, r2, r1
str r2, [r0, #EP93XX_OFF_SMCBCR7]
/* Set the PLL1 and processor clock. */
ldr r0, =SYSCON_BASE
#ifdef CONFIG_EDB9301
/* 332MHz, giving a 166MHz processor clock. */
ldr r1, = 0x02b49907
#else
#ifdef CONFIG_EDB93XX_INDUSTRIAL
/* 384MHz, giving a 196MHz processor clock. */
ldr r1, =0x02a4bb38
#else
/* 400MHz, giving a 200MHz processor clock. */
ldr r1, =0x02a4e39e
#endif
#endif
str r1, [r0, #SYSCON_OFF_CLKSET1]
nop
nop
nop
nop
nop
/* Need to make sure that SDRAM is configured correctly before
* coping the code into it.
*/
#ifdef CONFIG_EDB93XX_SDCS0
mov r11, #SDRAM_DEVCFG0_BASE
#endif
#ifdef CONFIG_EDB93XX_SDCS1
mov r11, #SDRAM_DEVCFG1_BASE
#endif
#ifdef CONFIG_EDB93XX_SDCS2
mov r11, #SDRAM_DEVCFG2_BASE
#endif
#ifdef CONFIG_EDB93XX_SDCS3
ldr r0, =SYSCON_BASE
ldr r0, [r0, #SYSCON_OFF_SYSCFG]
ands r0, r0, #SYSCON_SYSCFG_LASDO
moveq r11, #SDRAM_DEVCFG3_ASD0_BASE
movne r11, #SDRAM_DEVCFG3_ASD1_BASE
#endif
/* See Table 13-5 in EP93xx datasheet for more info about DRAM
* register mapping */
/* Try a 32-bit wide configuration of SDRAM. */
ldr r0, =(EP93XX_SDRAMCTRL_DEVCFG_BANKCOUNT | \
EP93XX_SDRAMCTRL_DEVCFG_SROMLL | \
EP93XX_SDRAMCTRL_DEVCFG_CASLAT_2 | \
EP93XX_SDRAMCTRL_DEVCFG_RASTOCAS_2)
/* Set burst count: 4 and CAS: 2
* Burst mode [A11:A10]; CAS [A16:A14]
*/
orr r2, r11, #0x00008800
bl ep93xx_sdram_config
/* Test the SDRAM. */
mov r0, r11
bl ep93xx_sdram_test
cmp r0, #0x00000000
beq ep93xx_sdram_done
/* Try a 16-bit wide configuration of SDRAM. */
ldr r0, =(EP93XX_SDRAMCTRL_DEVCFG_BANKCOUNT | \
EP93XX_SDRAMCTRL_DEVCFG_SROMLL | \
EP93XX_SDRAMCTRL_DEVCFG_CASLAT_2 | \
EP93XX_SDRAMCTRL_DEVCFG_RASTOCAS_2 | \
EP93XX_SDRAMCTRL_DEVCFG_EXTBUSWIDTH)
/* Set burst count: 8, CAS: 2, sequential burst
* Accoring to Table 13-3 for 16bit operations mapping must be shifted.
* Burst mode [A10:A9]; CAS [A15:A13]
*/
orr r2, r11, #0x00004600
bl ep93xx_sdram_config
/* Test the SDRAM. */
mov r0, r11
bl ep93xx_sdram_test
cmp r0, #0x00000000
beq ep93xx_sdram_done
/* Turn off the red LED. */
ldr r0, =EP93XX_LED_DATA
ldr r1, [r0]
bic r1, r1, #EP93XX_LED_RED_ON
str r1, [r0]
/* There is no SDRAM so flash the green LED. */
flash_green:
orr r1, r1, #EP93XX_LED_GREEN_ON
str r1, [r0]
ldr r2, =0x00010000
flash_green_delay_1:
subs r2, r2, #1
bne flash_green_delay_1
bic r1, r1, #EP93XX_LED_GREEN_ON
str r1, [r0]
ldr r2, =0x00010000
flash_green_delay_2:
subs r2, r2, #1
bne flash_green_delay_2
orr r1, r1, #EP93XX_LED_GREEN_ON
str r1, [r0]
ldr r2, =0x00010000
flash_green_delay_3:
subs r2, r2, #1
bne flash_green_delay_3
bic r1, r1, #EP93XX_LED_GREEN_ON
str r1, [r0]
ldr r2, =0x00050000
flash_green_delay_4:
subs r2, r2, #1
bne flash_green_delay_4
b flash_green
ep93xx_sdram_done:
ldr r1, =EP93XX_LED_DATA
ldr r0, [r1]
bic r0, r0, #EP93XX_LED_RED_ON
str r0, [r1]
/* Determine the size of the SDRAM. */
mov r0, r11
bl ep93xx_sdram_size
/* Save the SDRAM characteristics. */
mov r8, r0
mov r9, r1
mov r10, r2
/* Compute total memory size into r1 */
mul r1, r8, r10
#ifdef CONFIG_EDB93XX_SDCS0
ldr r2, [r0, #SDRAM_OFF_DEVCFG0]
#endif
#ifdef CONFIG_EDB93XX_SDCS1
ldr r2, [r0, #SDRAM_OFF_DEVCFG1]
#endif
#ifdef CONFIG_EDB93XX_SDCS2
ldr r2, [r0, #SDRAM_OFF_DEVCFG2]
#endif
#ifdef CONFIG_EDB93XX_SDCS3
ldr r2, [r0, #SDRAM_OFF_DEVCFG3]
#endif
/* Consider small DRAM size as:
* < 32Mb for 32bit bus
* < 64Mb for 16bit bus
*/
tst r2, #EP93XX_SDRAMCTRL_DEVCFG_EXTBUSWIDTH
moveq r1, r1, lsr #1
cmp r1, #0x02000000
#if defined(CONFIG_EDB9301)
/* Set refresh counter to 20ms for small DRAM size, otherwise 9.6ms */
movlt r1, #0x03f0
movge r1, #0x01e0
#else
/* Set refresh counter to 30.7ms for small DRAM size, otherwise 15ms */
movlt r1, #0x0600
movge r1, #0x2f0
#endif
str r1, [r0, #SDRAM_OFF_REFRSHTIMR]
/* Save the memory configuration information. */
orr r0, r11, #UBOOT_MEMORYCNF_BANK_SIZE
stmia r0, {r8-r11}
mov lr, r6
mov pc, lr