jz4740.c

ucos mips linux 光盘所得

/*
 * Jz4740 common routines
 *
 *  Copyright (c) 2006
 *  Ingenic Semiconductor, <[e-mail]>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <pavo.h>
#include <jz4740.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, 4, 4, 4, 4}; /* divisors of I:S:P:L:M */
	//int div[5] = {1, 3, 3, 3, 3}; /* divisors of I:S:P:L:M */
	int nf, pllout2;

	cfcr = CPM_CPCCR_CLKOEN |
		(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 UHC clock */
	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;

	

}

void sdram_init(void)
{
	register unsigned int dmcr, sdmode, tmp, cpu_clk, mem_clk, ns;
	volatile unsigned int delay;
	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_RTCSR = EMC_RTCSR_CKS_DISABLE;
	REG_EMC_RTCOR = 0;
	REG_EMC_RTCNT = 0;

	/* Basic DMCR register value. */
	dmcr = ((SDRAM_ROW-11)<<EMC_DMCR_RA_BIT) |
		((SDRAM_COL-8)<<EMC_DMCR_CA_BIT) |
		(SDRAM_BANK4<<EMC_DMCR_BA_BIT) |
		(SDRAM_BW16<<EMC_DMCR_BW_BIT) |
		EMC_DMCR_EPIN |
		cas_latency_dmcr[((SDRAM_CASL == 3) ? 1 : 0)];

	/* SDRAM timimg parameters */
	ns = 1000000000 / mem_clk;

	tmp = SDRAM_TRAS/ns;
	if (tmp < 4) tmp = 4;
	if (tmp > 11) tmp = 11;
	dmcr |= ((tmp-4) << EMC_DMCR_TRAS_BIT);

	tmp = SDRAM_RCD/ns;
	if (tmp > 3) tmp = 3;
	dmcr |= (tmp << EMC_DMCR_RCD_BIT);

	tmp = SDRAM_TPC/ns;
	if (tmp > 7) tmp = 7;
	dmcr |= (tmp << EMC_DMCR_TPC_BIT);

	tmp = SDRAM_TRWL/ns;
	if (tmp > 3) tmp = 3;
	dmcr |= (tmp << EMC_DMCR_TRWL_BIT);

	tmp = (SDRAM_TRAS + SDRAM_TPC)/ns;
	if (tmp > 14) tmp = 14;
	dmcr |= (((tmp + 1) >> 1) << EMC_DMCR_TRC_BIT);

	/* First, precharge phase */
	REG_EMC_DMCR = dmcr;

	/* Set refresh registers */
	tmp = SDRAM_TREF/ns;
	tmp = tmp/64 + 1;
	if (tmp > 0xff) tmp = 0xff;

	REG_EMC_RTCOR = tmp;
	REG_EMC_RTCSR = EMC_RTCSR_CKS_64;	/* Divisor is 64, CKO/64 */

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

	/* precharge all chip-selects */
	REG8(EMC_SDMR0|sdmode) = 0;

	/* wait for precharge, > 200us */
	delay = (cpu_clk / 1000000) * 200;
	while (delay--);

	/* enable refresh and set SDRAM mode */
	REG_EMC_DMCR = dmcr | EMC_DMCR_RFSH | EMC_DMCR_MRSET;

	/* write sdram mode register for each chip-select */
	REG8(EMC_SDMR0|sdmode) = 0;

	/* everything is ok now */
}