at91rm9200_lowlevel.c revision 164137
1/*- 2 * Copyright (c) 2006 M. Warner Losh. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 * 24 * This software is derived from software provide by Kwikbyte who specifically 25 * disclaimed copyright on the code. 26 * 27 * $FreeBSD: head/sys/boot/arm/at91/libat91/at91rm9200_lowlevel.c 164137 2006-11-09 20:32:36Z imp $ 28 */ 29 30#include "at91rm9200.h" 31#include "at91rm9200_lowlevel.h" 32 33extern int __bss_start__[]; 34extern int __bss_end__[]; 35 36#define BAUD 115200 37#define AT91C_US_ASYNC_MODE (AT91C_US_USMODE_NORMAL | AT91C_US_NBSTOP_1_BIT | \ 38 AT91C_US_PAR_NONE | AT91C_US_CHRL_8_BITS | AT91C_US_CLKS_CLOCK) 39 40/* 41 * void DefaultSystemInit(void) 42 * Load the system with sane values based on how the system is configured. 43 * at91rm9200_lowlevel.h is expected to define the necessary parameters. 44 */ 45void 46_init(void) 47{ 48 int *i; 49 50 AT91PS_USART pUSART = (AT91PS_USART)AT91C_BASE_DBGU; 51 AT91PS_PDC pPDC = (AT91PS_PDC)&(pUSART->US_RPR); 52 53 register unsigned value; 54 volatile sdram_size_t *p = (sdram_size_t *)SDRAM_BASE; 55 56#ifdef BOOT_TSC 57 // For the TSC board, we turn ON the one LED we have while 58 // early in boot. 59 AT91C_BASE_PIOC->PIO_PER = AT91C_PIO_PC10; 60 AT91C_BASE_PIOC->PIO_OER = AT91C_PIO_PC10; 61 AT91C_BASE_PIOC->PIO_CODR = AT91C_PIO_PC10; 62#endif 63 64#ifdef BOOT_KB920X 65 AT91C_BASE_PIOC->PIO_PER = AT91C_PIO_PC18 | AT91C_PIO_PC19 | 66 AT91C_PIO_PC20; 67 AT91C_BASE_PIOC->PIO_OER = AT91C_PIO_PC18 | AT91C_PIO_PC19 | 68 AT91C_PIO_PC20; 69 AT91C_BASE_PIOC->PIO_SODR = AT91C_PIO_PC18 | AT91C_PIO_PC19 | 70 AT91C_PIO_PC20; 71 AT91C_BASE_PIOC->PIO_CODR = AT91C_PIO_PC18; 72#endif 73 74 // configure clocks 75 // assume: 76 // main osc = 10Mhz 77 // PLLB configured for 96MHz (48MHz after div) 78 // CSS = PLLB 79 // set PLLA = 180MHz 80 // assume main osc = 10Mhz 81 // div = 5 , out = 2 (150MHz = 240MHz) 82 value = AT91C_BASE_CKGR->CKGR_PLLAR; 83 value &= ~(AT91C_CKGR_DIVA | AT91C_CKGR_OUTA | AT91C_CKGR_MULA); 84 value |= OSC_MAIN_FREQ_DIV | AT91C_CKGR_OUTA_2 | AT91C_CKGR_SRCA | 85 ((OSC_MAIN_MULT - 1) << 16); 86 AT91C_BASE_CKGR->CKGR_PLLAR = value; 87 88 // wait for lock 89 while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA)) 90 continue; 91 92 // change divider = 3, pres = 1 93 value = AT91C_BASE_PMC->PMC_MCKR; 94 value &= ~(AT91C_PMC_MDIV | AT91C_PMC_PRES); 95 value |= AT91C_PMC_MDIV_3 | AT91C_PMC_PRES_CLK; 96 AT91C_BASE_PMC->PMC_MCKR = value; 97 98 // wait for update 99 while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY)) 100 continue; 101 102 // change CSS = PLLA 103 value &= ~AT91C_PMC_CSS; 104 value |= AT91C_PMC_CSS_PLLA_CLK; 105 AT91C_BASE_PMC->PMC_MCKR = value; 106 107 // wait for update 108 while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY)) 109 continue; 110 111#ifdef BOOT_KB920X 112 // setup flash access (allow ample margin) 113 // 9 wait states, 1 setup, 1 hold, 1 float for 8-bit device 114 ((AT91PS_SMC2)AT91C_BASE_SMC2)->SMC2_CSR[0] = 115 AT91C_SMC2_WSEN | 116 (9 & AT91C_SMC2_NWS) | 117 ((1 << 8) & AT91C_SMC2_TDF) | 118 AT91C_SMC2_DBW_8 | 119 ((1 << 24) & AT91C_SMC2_RWSETUP) | 120 ((1 << 29) & AT91C_SMC2_RWHOLD); 121#endif 122 123 // setup SDRAM access 124 // EBI chip-select register (CS1 = SDRAM controller) 125 // 9 col, 13row, 4 bank, CAS2 126 // write recovery = 2 (Twr) 127 // row cycle = 5 (Trc) 128 // precharge delay = 2 (Trp) 129 // row to col delay 2 (Trcd) 130 // active to precharge = 4 (Tras) 131 // exit self refresh to active = 6 (Txsr) 132 value = ((AT91PS_EBI)AT91C_BASE_EBI)->EBI_CSA; 133 value &= ~AT91C_EBI_CS1A; 134 value |= AT91C_EBI_CS1A_SDRAMC; 135 AT91C_BASE_EBI->EBI_CSA = value; 136 137 AT91C_BASE_SDRC->SDRC_CR = 138 AT91C_SDRC_NC_9 | 139 AT91C_SDRC_NR_13 | 140 AT91C_SDRC_NB_4_BANKS | 141 AT91C_SDRC_CAS_2 | 142 ((2 << 7) & AT91C_SDRC_TWR) | 143 ((5 << 11) & AT91C_SDRC_TRC) | 144 ((2 << 15) & AT91C_SDRC_TRP) | 145 ((2 << 19) & AT91C_SDRC_TRCD) | 146 ((4 << 23) & AT91C_SDRC_TRAS) | 147 ((6 << 27) & AT91C_SDRC_TXSR); 148 149 // Step 1: We assume 200us of idle time. 150 // Step 2: Issue an all banks precharge command 151 AT91C_BASE_SDRC->SDRC_MR = SDRAM_WIDTH | AT91C_SDRC_MODE_PRCGALL_CMD; 152 *p = 0; 153 154 // Step 3: Issue 8 Auto-refresh (CBR) cycles 155 AT91C_BASE_SDRC->SDRC_MR = SDRAM_WIDTH | AT91C_SDRC_MODE_RFSH_CMD; 156 *p = 0; 157 *p = 0; 158 *p = 0; 159 *p = 0; 160 *p = 0; 161 *p = 0; 162 *p = 0; 163 *p = 0; 164 165 // Step 4: Issue an Mode Set Register (MRS) cycle to program in 166 // the parameters that we setup in the SDRC_CR register above. 167 AT91C_BASE_SDRC->SDRC_MR = SDRAM_WIDTH | AT91C_SDRC_MODE_LMR_CMD; 168 *p = 0; 169 170 // Step 5: set the refresh timer and access memory to start it 171 // running. We have to wait 3 clocks after the LMR_CMD above, 172 // and this fits the bill nicely. 173 AT91C_BASE_SDRC->SDRC_TR = 7 * AT91C_MASTER_CLOCK / 1000000; 174 *p = 0; 175 176 // Step 6: Set normal mode. 177 AT91C_BASE_SDRC->SDRC_MR = SDRAM_WIDTH | AT91C_SDRC_MODE_NORMAL_CMD; 178 *p = 0; 179 180#if SDRAM_WIDTH == AT91C_SDRC_DBW_32_BITS 181 // Turn on the upper 16 bits on the SDRAM bus. 182 AT91C_BASE_PIOC->PIO_ASR = 0xffff0000; 183 AT91C_BASE_PIOC->PIO_PDR = 0xffff0000; 184#endif 185 // Configure DBGU -use local routine optimized for space 186 AT91C_BASE_PIOA->PIO_ASR = AT91C_PA31_DTXD | AT91C_PA30_DRXD; 187 AT91C_BASE_PIOA->PIO_PDR = AT91C_PA31_DTXD | AT91C_PA30_DRXD; 188 pUSART->US_IDR = (unsigned int) -1; 189 pUSART->US_CR = 190 AT91C_US_RSTRX | AT91C_US_RSTTX | AT91C_US_RXDIS | AT91C_US_TXDIS; 191 pUSART->US_BRGR = ((((AT91C_MASTER_CLOCK*10)/(BAUD*16))+5)/10); 192 pUSART->US_TTGR = 0; 193 pPDC->PDC_PTCR = AT91C_PDC_RXTDIS; 194 pPDC->PDC_PTCR = AT91C_PDC_TXTDIS; 195 pPDC->PDC_TNPR = 0; 196 pPDC->PDC_TNCR = 0; 197 198 pPDC->PDC_RNPR = 0; 199 pPDC->PDC_RNCR = 0; 200 201 pPDC->PDC_TPR = 0; 202 pPDC->PDC_TCR = 0; 203 204 pPDC->PDC_RPR = 0; 205 pPDC->PDC_RCR = 0; 206 207 pPDC->PDC_PTCR = AT91C_PDC_RXTEN; 208 pPDC->PDC_PTCR = AT91C_PDC_TXTEN; 209 210 pUSART->US_MR = AT91C_US_ASYNC_MODE; 211 pUSART->US_CR = AT91C_US_TXEN; 212 pUSART->US_CR = AT91C_US_RXEN; 213 214 /* Zero BSS now that we have memory setup */ 215 i = (int *)__bss_start__; 216 while (i < (int *)__bss_end__) 217 *i++ = 0; 218} 219