/*
* SMFD board hardware initialization.
*/
/*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
* Alexandra Kossovsky <sasha@oktet.ru>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include "rtems/score/sh7750_regs.h"
#include "rtems/score/sh_io.h"
#include "sdram.h"
#include "bsp.h"
/* early_hw_init --
* Perform initial hardware initialization:
* - setup clock generator
* - initialize bus state controller, memory settings, SDRAM
* - disable DMA
* - setup external ports, etc.
* - initialize interrupt controller
*
* This function should not access the memory! It should be compiled
* with -fomit-frame-pointer to avoid stack access.
*/
void early_hw_init(void)
{
/* Explicitly turn off the MMU */
write32(0, SH7750_MMUCR);
/* Disable instruction and operand caches */
write32(0, SH7750_CCR);
/* Setup Clock Generator */
/*
* Input clock frequency is 16 MHz, MD0=1,
* CPU clock frequency already selected to 96MHz.
* Bus clock frequency should be set to 48 MHz, therefore divider 2
* should be applied (bus frequency is 48 MHz, clock period is 20.84ns).
* Peripheral frequency should be set to 24 MHz, therefore divider 4
* should be used.
*/
/* Prepare watchdog timer for frequency changing */
write16((read8(SH7750_WTCSR) & ~SH7750_WTCSR_TME) |
SH7750_WTCSR_KEY, SH7750_WTCSR);
write16(SH7750_WTCSR_MODE_IT | SH7750_WTCSR_CKS_DIV4096 |
SH7750_WTCSR_KEY, SH7750_WTCSR);
/* Turn PLL1 on */
write16(0x40 | SH7750_WTCNT_KEY, SH7750_WTCNT);
write16(read16(SH7750_FRQCR) | SH7750_FRQCR_PLL1EN, SH7750_FRQCR);
/* Perform Frequency Selection */
write16(0x40 | SH7750_WTCNT_KEY, SH7750_WTCNT);
write16(SH7750_FRQCR_CKOEN | SH7750_FRQCR_PLL1EN |
SH7750_FRQCR_IFCDIV1 | SH7750_FRQCR_BFCDIV2 | SH7750_FRQCR_PFCDIV4,
SH7750_FRQCR);
/* Turn PLL2 on */
write16(0x40 | SH7750_WTCNT_KEY, SH7750_WTCNT);
write16(read16(SH7750_FRQCR) | SH7750_FRQCR_PLL2EN, SH7750_FRQCR);
/* Bus State Controller Initialization */
/*
* Area assignments:
* Area 0: Flash memory, SRAM interface
* Area 1: GDC
* Area 2: SDRAM
* Area 3-6: unused
*/
write32(
/* Pull-ups (IPUP, OPUP) enabled */
/* No Byte-Control SRAM mode for Area 1 and Area 3 */
SH7750_BCR1_BREQEN | /* Enable external bus requests */
/* No Partial Sharing Mode */
/* No MPX interface */
/* Memory and Control Signals are in HiZ */
SH7750_BCR1_A0BST_SRAM | /* No burst ROM in flash */
SH7750_BCR1_A5BST_SRAM | /* Area 5 is not in use */
SH7750_BCR1_A6BST_SRAM | /* Area 6 is not in use */
SH7750_BCR1_DRAMTP_2SDRAM_3SDRAM /* Select Area 2 SDRAM type */
/* Area 5,6 programmed as a SRAM interface (not PCMCIA) */,
SH7750_BCR1);
write16(
(SH7750_BCR2_SZ_8 << SH7750_BCR2_A0SZ_S) | /* These bits is read-only
and set during reset */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A6SZ_S) | /* Area 6 not used */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A5SZ_S) | /* Area 5 not used */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A4SZ_S) | /* Area 4 not used */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A3SZ_S) | /* Area 3 not used */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A2SZ_S) | /* SDRAM is 32-bit width */
(SH7750_BCR2_SZ_32 << SH7750_BCR2_A1SZ_S) | /* GDC is 32-bit width */
SH7750_BCR2_PORTEN, /* Use D32-D51 as a port */
SH7750_BCR2);
write32(
(0 << SH7750_WCR1_DMAIW_S) | /* 0 required for SDRAM RAS down mode */
(7 << SH7750_WCR1_A6IW_S) | /* Area 6 not used */
(7 << SH7750_WCR1_A5IW_S) | /* Area 5 not used */
(7 << SH7750_WCR1_A4IW_S) | /* Area 4 not used */
(7 << SH7750_WCR1_A3IW_S) | /* Area 3 not used */
(1 << SH7750_WCR1_A2IW_S) | /* 1 idle cycles inserted between acc */
(7 << SH7750_WCR1_A1IW_S) | /* Don't have GDC specs... Set safer. */
(1 << SH7750_WCR1_A0IW_S), /* 1 idle cycles inserted between acc */
SH7750_WCR1);
write32(
(SH7750_WCR2_WS15 << SH7750_WCR2_A6W_S) | /* Area 6 not used */
(SH7750_WCR2_BPWS7 << SH7750_WCR2_A6B_S) |
(SH7750_WCR2_WS15 << SH7750_WCR2_A5W_S) | /* Area 5 not used */
(SH7750_WCR2_BPWS7 << SH7750_WCR2_A5B_S) |
(SH7750_WCR2_WS15 << SH7750_WCR2_A4W_S) | /* Area 4 not used */
(SH7750_WCR2_WS15 << SH7750_WCR2_A3W_S) | /*Area 3 not used*/
(SH7750_WCR2_SDRAM_CAS_LAT2 << SH7750_WCR2_A2W_S) | /* SDRAM CL = 2 */
(SH7750_WCR2_WS15 << SH7750_WCR2_A1W_S) | /* Area 1 (GDC)
requirements not known*/
(SH7750_WCR2_WS6 << SH7750_WCR2_A0W_S) | /* 4 wait states required
at 48MHz for 70ns mem.,
set closest greater */
(SH7750_WCR2_BPWS7 << SH7750_WCR2_A0B_S), /* burst mode disabled for
Area 0 flash ROM */
SH7750_WCR2);
write32(
SH7750_WCR3_A6S | /* Area 6 not used */
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A6H_S) |
SH7750_WCR3_A5S | /* Area 5 not used */
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A5H_S) |
SH7750_WCR3_A4S | /* Area 4 not used */
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A4H_S) |
SH7750_WCR3_A3S | /* Area 3 not used */
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A3H_S) |
SH7750_WCR3_A2S | /* SDRAM - ignored */
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A2H_S) |
SH7750_WCR3_A1S | /* GDC - unknown, set max*/
(SH7750_WCR3_DHWS_3 << SH7750_WCR3_A1H_S) |
0 | /* flash ROM - no write strobe setup time required */
(SH7750_WCR3_DHWS_0 << SH7750_WCR3_A0H_S),
SH7750_WCR3);
#define MCRDEF \
/* SH7750_MCR_RASD | */ /* Set RAS Down mode */ \
(SH7750_MCR_TRC_0 | SH7750_MCR_TRAS_SDRAM_TRC_4 | \
/* RAS precharge time is 63ns; it corresponds to 4 clocks */ \
/* TCAS valid only for DRAM interface */ \
SH7750_MCR_TPC_SDRAM_1 | /* TPC = 20ns = 1 clock */ \
SH7750_MCR_RCD_SDRAM_2 | /* RCD = 21ns = 2 clock */ \
/* After write, next active command is not issued for a period of \
TPC + TRWL. SDRAM specifies that it should be BL+Trp clocks when \
CL=2. Trp = 20ns = 1clock; BL=8. Therefore we should wait 9 \
clocks. Don't know why, but 6 clocks (TRWL=5 and TPC=1) seems \
working. May be, something wrong in documentation? */ \
SH7750_MCR_TRWL_5 | /* TRWL = 5 clock */ \
SH7750_MCR_BE | /* Always enabled for SDRAM */ \
SH7750_MCR_SZ_32 | /* Memory data size is 32 bit */ \
(4 << SH7750_MCR_AMX_S) | /* Select memory device type */ \
SH7750_MCR_RFSH | /* Refresh is performed */ \
SH7750_MCR_RMODE_NORMAL) /* Auto-Refresh mode */
/* Clear refresh timer counter */
write16(SH7750_RTCNT_KEY | 0, SH7750_RTCNT);
/* Time between auto-refresh commands is 15.6 microseconds; refresh
timer counter frequency is 12 MHz; 1.56e-5*1.2e7= 187.2, therefore
program the refresh timer divider to 187 */
write16(SH7750_RTCOR_KEY | 187, SH7750_RTCOR);
/* Clear refresh counter */
write16(SH7750_RFCR_KEY | 0, SH7750_RFCR);
/* Select refresh counter base frequency as bus frequency/4 = 12 MHz */
write16(SH7750_RTCSR_CKS_CKIO_DIV4 | SH7750_RTCSR_KEY, SH7750_RTCSR);
/* Initialize Memory Control Register; disable refresh */
write32((MCRDEF & ~SH7750_MCR_RFSH) | SH7750_MCR_PALL, SH7750_MCR);
/* SDRAM power-up initialization require 100 microseconds delay after
stable power and clock fed; 100 microseconds corresponds to 7 refresh
intervals */
while (read16(SH7750_RFCR) <= 7);
/* Clear refresh timer counter */
write16(SH7750_RTCNT_KEY | 0, SH7750_RTCNT);
/* Clear refresh counter */
write16(SH7750_RFCR_KEY | 0, SH7750_RFCR);
/* Execute Precharge All command */
write32(0, SH7750_SDRAM_MODE_A2_32BIT(0));
/* Initialize Memory Control Register; enable refresh, prepare to
SDRAM mode register setting */
write32(MCRDEF | SH7750_MCR_MRSET, SH7750_MCR);
/* Wait until at least 2 auto-refresh commands to be executed */
while (read16(SH7750_RFCR) <= 10);
/* SDRAM data width is 32 bit (4 bytes), cache line size is 32 bytes,
therefore burst length is 8 (32 / 4) */
write8(0,SH7750_SDRAM_MODE_A2_32BIT(
SDRAM_MODE_BL_8 |
SDRAM_MODE_BT_SEQ | /* Only sequential burst mode supported
in SH7750 */
SDRAM_MODE_CL_2 | /* CAS latency is 2 */
SDRAM_MODE_OPC_BRBW) /* Burst read/burst write */
);
/* Bus State Controller initialized now */
/* Disable DMA controller */
write32(0, SH7750_DMAOR);
/* I/O port setup */
/* Configure all port bits as output - to fasciliate debugging */
write32(
SH7750_PCTRA_PBOUT(0) | SH7750_PCTRA_PBOUT(1) |
SH7750_PCTRA_PBOUT(2) | SH7750_PCTRA_PBOUT(3) |
SH7750_PCTRA_PBOUT(4) | SH7750_PCTRA_PBOUT(5) |
SH7750_PCTRA_PBOUT(6) | SH7750_PCTRA_PBOUT(7) |
SH7750_PCTRA_PBOUT(8) | SH7750_PCTRA_PBOUT(9) |
SH7750_PCTRA_PBOUT(10) | SH7750_PCTRA_PBOUT(11) |
SH7750_PCTRA_PBOUT(12) | SH7750_PCTRA_PBOUT(13) |
SH7750_PCTRA_PBOUT(14) | SH7750_PCTRA_PBOUT(15),
SH7750_PCTRA);
write32(
SH7750_PCTRB_PBOUT(16) | SH7750_PCTRB_PBOUT(17) |
SH7750_PCTRB_PBOUT(18) | SH7750_PCTRB_PBOUT(19),
SH7750_PCTRB);
/* Clear data in port */
write32(0, SH7750_PDTRA);
write32(0, SH7750_PDTRB);
/* Interrupt Controller Initialization */
write16(SH7750_ICR_IRLM, SH7750_ICR); /* IRLs serves as an independent
interrupt request lines */
/* Mask all requests at this time */
write16(
(0 << SH7750_IPRA_TMU0_S) |
(0 << SH7750_IPRA_TMU1_S) |
(0 << SH7750_IPRA_TMU2_S) |
(0 << SH7750_IPRA_RTC_S),
SH7750_IPRA);
write16(
(0 << SH7750_IPRB_WDT_S) |
(0 << SH7750_IPRB_REF_S) |
(0 << SH7750_IPRB_SCI1_S),
SH7750_IPRB);
write16(
(0 << SH7750_IPRC_GPIO_S) |
(0 << SH7750_IPRC_DMAC_S) |
(0 << SH7750_IPRC_SCIF_S) |
(0 << SH7750_IPRC_HUDI_S),
SH7750_IPRC);
}
/*
* cache_on --
* Enable instruction and operand caches
*/
void bsp_cache_on(void)
{
switch (boot_mode) {
case SH4_BOOT_MODE_FLASH:
write32(SH7750_CCR_ICI | SH7750_CCR_ICE |
SH7750_CCR_OCI | SH7750_CCR_CB | SH7750_CCR_OCE,
SH7750_CCR);
break;
case SH4_BOOT_MODE_IPL:
__asm__ volatile (
"mov #6, r0\n"
"xor r4, r4\n"
"trapa #0x3f\n"
: : : "r0", "r4");
break;
default: /* unreachable */
break;
}
}
