diff options
Diffstat (limited to 'arch/arm/cpu/arm920t')
| -rw-r--r-- | arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S | 463 |
1 files changed, 436 insertions, 27 deletions
diff --git a/arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S b/arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S index bf2fa2ac32..cfad206edd 100644 --- a/arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S +++ b/arch/arm/cpu/arm920t/ep93xx/lowlevel_init.S @@ -2,48 +2,457 @@ * 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 <version.h> -#include <asm/arch/ep93xx.h> +#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: - /* backup return address */ - ldr r1, =SYSCON_SCRATCH0 - str lr, [r1] - /* Turn on both LEDs */ - bl red_led_on - bl green_led_on + 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 + - /* Configure flash wait states before we switch to the PLL */ - bl flash_cfg +ep93xx_sdram_done: + ldr r1, =EP93XX_LED_DATA + ldr r0, [r1] + bic r0, r0, #EP93XX_LED_RED_ON + str r0, [r1] - /* Set up PLL */ - bl pll_cfg + /* Determine the size of the SDRAM. */ + mov r0, r11 + bl ep93xx_sdram_size - /* Turn off the Green LED and leave the Red LED on */ - bl green_led_off + /* Save the SDRAM characteristics. */ + mov r8, r0 + mov r9, r1 + mov r10, r2 - /* Setup SDRAM */ - bl sdram_cfg + /* 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 - /* Turn on Green LED, Turn off the Red LED */ - bl green_led_on - bl red_led_off + /* 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 - /* FIXME: we use async mode for now */ - mrc p15, 0, r0, c1, c0, 0 - orr r0, r0, #0xc0000000 - mcr p15, 0, r0, c1, c0, 0 +#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] - /* restore return address */ - ldr r1, =SYSCON_SCRATCH0 - ldr lr, [r1] + /* Save the memory configuration information. */ + orr r0, r11, #UBOOT_MEMORYCNF_BANK_SIZE + stmia r0, {r8-r11} - mov pc, lr + mov lr, r6 + mov pc, lr |