diff options
Diffstat (limited to 'arch/arm/boards/imx27ads/lowlevel_init.S')
| -rw-r--r-- | arch/arm/boards/imx27ads/lowlevel_init.S | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/arm/boards/imx27ads/lowlevel_init.S b/arch/arm/boards/imx27ads/lowlevel_init.S new file mode 100644 index 0000000000..df12aead00 --- /dev/null +++ b/arch/arm/boards/imx27ads/lowlevel_init.S @@ -0,0 +1,172 @@ +/* + * For clock initialization, see chapter 3 of the "MCIMX27 Multimedia + * Applications Processor Reference Manual, Rev. 0.2". + * + */ + +#include <config.h> +#include <mach/imx-regs.h> + +#define writel(val, reg) \ + ldr r0, =reg; \ + ldr r1, =val; \ + str r1, [r0]; + +#define CRM_PLL_PCTL_PARAM(pd, fd, fi, fn) (((pd-1)<<26) + ((fd-1)<<16) + (fi<<10) + (fn<<0)) + +.macro sdram_init_sha + /* + * DDR on CSD0 + */ + writel(0x00000008, 0xD8001010) + writel(0x55555555, 0x10027828) + writel(0x55555555, 0x10027830) + writel(0x55555555, 0x10027834) + writel(0x00005005, 0x10027838) + writel(0x15555555, 0x1002783C) + writel(0x00000004, 0xD8001010) + writel(0x006ac73a, 0xD8001004) + writel(0x92100000, 0xD8001000) + writel(0x00000000, 0xA0000F00) + writel(0xA2100000, 0xD8001000) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0xA2200000, 0xD8001000) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0x00000000, 0xA0000F00) + writel(0xb2100000, 0xD8001000) + ldr r0, =0xA0000033 + mov r1, #0xda + strb r1, [r0] + ldr r0, =0xA1000000 + mov r1, #0xff + strb r1, [r0] + writel(0x82226080, 0xD8001000) +.endm + +.macro sdram_init_mx27_manual + /* + * sdram init sequence, as defined in 18.5.4 of the i.MX27 reference manual + */ +1: + ldr r2, =ESD_ESDCTL0 /* base address of registers */ + ldr r3, =PRE_ALL_CMD /* SMODE=001 */ + str r3,(r2,#0x0) /* put CSD0 in precharge command mode */ + ldr r4, =SDRAM_CSD0 /* CSD0 precharge address (A10=1) */ + str r1,(r4,#0x0) /* precharge CSD0 all banks */ + ldr r3, =AUTO_REF_CMD /* SMODE=010 */ + str r3,(r2,#0x0) /* put array 0 in auto-refresh mode */ + ldr r4, =SDRAM_CSD0_BASE /* CSD0 base address */ + ldr r6,=0x7 /* load loop counter */ +1: ldr r5,(r4,#0x0) /* run auto-refresh cycle to array 0 */ + subs r6,r6,#1 /* decrease counter value */ + bne 1b + ldr r3, =SET_MODE_REG_CMD /* SMODE=011 */ + str r3,(r2,#0x0) /* setup CSD0 for mode register write */ + ldr r3, =MODE_REG_VAL0 /* array 0 mode register value */ + ldrb r5,(r3,#0x0) /* New mode register value on address bus */ + ldr r3, =NORMAL_MODE /* SMODE=000 */ + str r3,(r2,#0x0) /* setup CSD0 for normal operation */ + +ESD_ESDCTL0 .long 0xD8001000 // system/external device dependent data +SDRAM_CSD0 .long 0x00000000 // system/external device dependent data +SDRAM_CSD0_BASE .long 0x00000000 // system/external device dependent data +PRE_ALL_CMD .long 0x00000000 // system/external device dependent data (SMODE=001) +AUTO_REF_CMD .long 0x00000000 // system/external device dependent data (SMODE=010) +SET_MODE_REG_CMD .long 0x00000000 // system/external device dependent data (SMODE=011) +MODE_REG_VAL0 .long 0x00000000 // system/external device dependent data +NORMAL_MODE .long 0x00000000 // system/external device dependent data (SMODE=000) +.endm + +.macro sdram_init_barebox + /* configure 16 bit nor flash on cs0 */ + writel(0x0000CC03, 0xd8002000) + writel(0xa0330D01, 0xd8002004) + writel(0x00220800, 0xd8002008) + + /* ddr on csd0 - initial reset */ + writel(0x00000008, 0xD8001010) + + /* configure ddr on csd0 - wait 5000 cycles */ + writel(0x00000004, 0xD8001010) + writel(0x006ac73a, 0xD8001004) + writel(0x92100000, 0xD8001000) + writel(0x12344321, 0xA0000f00) + writel(0xa2100000, 0xD8001000) + writel(0x12344321, 0xA0000000) + writel(0x12344321, 0xA0000000) + writel(0xb2100000, 0xD8001000) + ldr r0, =0xA0000033 + mov r1, #0xda + strb r1, [r0] + ldr r0, =0xA1000000 + mov r1, #0xff + strb r1, [r0] + writel(0x82226080, 0xD8001000) + writel(0xDEADBEEF, 0xA0000000) + writel(0x0000000c, 0xD8001010) +.endm + +.globl board_init_lowlevel +board_init_lowlevel: + + mov r10, lr + + /* ahb lite ip interface */ + writel(0x20040304, AIPI1_PSR0) + writel(0xDFFBFCFB, AIPI1_PSR1) + writel(0x00000000, AIPI2_PSR0) + writel(0xFFFFFFFF, AIPI2_PSR1) + + /* disable mpll/spll */ + ldr r0, =CSCR + ldr r1, [r0] + bic r1, r1, #0x03 + str r1, [r0] + + /* + * pll clock initialization - see section 3.4.3 of the i.MX27 manual + * + * FIXME: Using the 399*2 MHz values from table 3-8 doens't work + * with 1.2 V core voltage! Find out if this is + * documented somewhere. + */ + writel(0x00191403, MPCTL0) /* MPLL = 199.5*2 MHz */ + writel(0x040C2403, SPCTL0) /* SPLL = FIXME (needs review) */ + + /* + * ARM clock = (399 MHz / 2) / (ARM divider = 1) = 200 MHz + * AHB clock = (399 MHz / 3) / (AHB divider = 2) = 66.5 MHz + * System clock (HCLK) = 133 MHz + */ + writel(0x33F30307 | CSCR_MPLL_RESTART | CSCR_SPLL_RESTART, CSCR) + + /* add some delay here */ + mov r1, #0x1000 +1: subs r1, r1, #0x1 + bne 1b + + /* clock gating enable */ + writel(0x00050f08, GPCR) + + /* peripheral clock divider */ + writel(0x23C8F403, PCDR0) /* FIXME */ + writel(0x09030913, PCDR1) /* PERDIV1=08 @133 MHz */ + /* PERDIV1=04 @266 MHz * + * / + /* skip sdram initialization if we run from ram */ + cmp pc, #0xa0000000 + bls 1f + cmp pc, #0xc0000000 + bhi 1f + + mov pc,r10 +1: + sdram_init_sha + + mov pc,r10 + |