xburst-tools/nandboot/src/jz4740.c

/*
 * jz4740.c
 *
 * JZ4740 common routines
 *
 * Copyright (c) 2005-2008  Ingenic Semiconductor Inc.
 * Author: Peter Wei <jlwei@ingenic.cn>
 *
 * 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.
 */

#include <config.h>

#ifdef CONFIG_JZ4740

#include <jz4740.h>
#include <jz4740_board.h>

/* PLL output clock = EXTAL * NF / (NR * NO)
 *
 * NF = FD + 2, NR = RD + 2
 * NO = 1 (if OD = 0), NO = 2 (if OD = 1 or 2), NO = 4 (if OD = 3)
 */
void pll_init(void)
{
	register unsigned int cfcr, plcr1;
	int n2FR[33] = {
		0, 0, 1, 2, 3, 0, 4, 0, 5, 0, 0, 0, 6, 0, 0, 0,
		7, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0,
		9
	};
	int div[5] = {1, 3, 3, 3, 3}; /* divisors of I:S:P:M:L */
	int nf, pllout2;

	cfcr = CPM_CPCCR_CLKOEN |
		CPM_CPCCR_PCS |
		(n2FR[div[0]] << CPM_CPCCR_CDIV_BIT) | 
		(n2FR[div[1]] << CPM_CPCCR_HDIV_BIT) | 
		(n2FR[div[2]] << CPM_CPCCR_PDIV_BIT) |
		(n2FR[div[3]] << CPM_CPCCR_MDIV_BIT) |
		(n2FR[div[4]] << CPM_CPCCR_LDIV_BIT);

	pllout2 = (cfcr & CPM_CPCCR_PCS) ? CFG_CPU_SPEED : (CFG_CPU_SPEED / 2);

	/* Init USB Host clock, pllout2 must be n*48MHz */
	REG_CPM_UHCCDR = pllout2 / 48000000 - 1;

	nf = CFG_CPU_SPEED * 2 / CFG_EXTAL;
	plcr1 = ((nf - 2) << CPM_CPPCR_PLLM_BIT) | /* FD */
		(0 << CPM_CPPCR_PLLN_BIT) |	/* RD=0, NR=2 */
		(0 << CPM_CPPCR_PLLOD_BIT) |    /* OD=0, NO=1 */
		(0x20 << CPM_CPPCR_PLLST_BIT) | /* PLL stable time */
		CPM_CPPCR_PLLEN;                /* enable PLL */          

	/* init PLL */
	REG_CPM_CPCCR = cfcr;
	REG_CPM_CPPCR = plcr1;
}

/*
 * Init SDRAM memory.
 */
void sdram_init(void)
{
	register unsigned int dmcr0, dmcr, sdmode, tmp, cpu_clk, mem_clk, ns;

	unsigned int cas_latency_sdmr[2] = {
		EMC_SDMR_CAS_2,
		EMC_SDMR_CAS_3,
	};

	unsigned int cas_latency_dmcr[2] = {
		1 << EMC_DMCR_TCL_BIT,	/* CAS latency is 2 */
		2 << EMC_DMCR_TCL_BIT	/* CAS latency is 3 */
	};

	int div[] = {1, 2, 3, 4, 6, 8, 12, 16, 24, 32};

	cpu_clk = CFG_CPU_SPEED;
	mem_clk = cpu_clk * div[__cpm_get_cdiv()] / div[__cpm_get_mdiv()];

	REG_EMC_BCR = 0;	/* Disable bus release */
	REG_EMC_RTCSR = 0;	/* Disable clock for counting */

	/* Fault DMCR value for mode register setting*/
#define SDRAM_ROW0    11
#define SDRAM_COL0     8
#define SDRAM_BANK40   0

	dmcr0 = ((SDRAM_ROW0-11)<<EMC_DMCR_RA_BIT) |
		((SDRAM_COL0-8)<<EMC_DMCR_CA_BIT) |
		(SDRAM_BANK40<<EMC_DMCR_BA_BIT) |
		(CFG_SDRAM_BW16<<EMC_DMCR_BW_BIT) |
		EMC_DMCR_EPIN |
		cas_latency_dmcr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

	/* Basic DMCR value */
	dmcr = ((CFG_SDRAM_ROW-11)<<EMC_DMCR_RA_BIT) |
		((CFG_SDRAM_COL-8)<<EMC_DMCR_CA_BIT) |
		(CFG_SDRAM_BANK4<<EMC_DMCR_BA_BIT) |
		(CFG_SDRAM_BW16<<EMC_DMCR_BW_BIT) |
		EMC_DMCR_EPIN |
		cas_latency_dmcr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

	/* SDRAM timimg */
	ns = 1000000000 / mem_clk;
	tmp = CFG_SDRAM_TRAS/ns;
	if (tmp < 4) tmp = 4;
	if (tmp > 11) tmp = 11;
	dmcr |= ((tmp-4) << EMC_DMCR_TRAS_BIT);
	tmp = CFG_SDRAM_RCD/ns;
	if (tmp > 3) tmp = 3;
	dmcr |= (tmp << EMC_DMCR_RCD_BIT);
	tmp = CFG_SDRAM_TPC/ns;
	if (tmp > 7) tmp = 7;
	dmcr |= (tmp << EMC_DMCR_TPC_BIT);
	tmp = CFG_SDRAM_TRWL/ns;
	if (tmp > 3) tmp = 3;
	dmcr |= (tmp << EMC_DMCR_TRWL_BIT);
	tmp = (CFG_SDRAM_TRAS + CFG_SDRAM_TPC)/ns;
	if (tmp > 14) tmp = 14;
	dmcr |= (((tmp + 1) >> 1) << EMC_DMCR_TRC_BIT);

	/* SDRAM mode value */
	sdmode = EMC_SDMR_BT_SEQ | 
		 EMC_SDMR_OM_NORMAL |
		 EMC_SDMR_BL_4 | 
		 cas_latency_sdmr[((CFG_SDRAM_CASL == 3) ? 1 : 0)];

	/* Stage 1. Precharge all banks by writing SDMR with DMCR.MRSET=0 */
	REG_EMC_DMCR = dmcr;
	REG8(EMC_SDMR0|sdmode) = 0;

	/* Wait for precharge, > 200us */
	tmp = (cpu_clk / 1000000) * 1000;
	while (tmp--);

	/* Stage 2. Enable auto-refresh */
	REG_EMC_DMCR = dmcr | EMC_DMCR_RFSH;

	tmp = CFG_SDRAM_TREF/ns;
	tmp = tmp/64 + 1;
	if (tmp > 0xff) tmp = 0xff;
	REG_EMC_RTCOR = tmp;
	REG_EMC_RTCNT = 0;
	REG_EMC_RTCSR = EMC_RTCSR_CKS_64;	/* Divisor is 64, CKO/64 */

	/* Wait for number of auto-refresh cycles */
	tmp = (cpu_clk / 1000000) * 1000;
	while (tmp--);

 	/* Stage 3. Mode Register Set */
	REG_EMC_DMCR = dmcr0 | EMC_DMCR_RFSH | EMC_DMCR_MRSET;
	REG8(EMC_SDMR0|sdmode) = 0;

        /* Set back to basic DMCR value */
	REG_EMC_DMCR = dmcr | EMC_DMCR_RFSH | EMC_DMCR_MRSET;

	/* everything is ok now */
}

#endif /* CONFIG_JZ4740 */