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author | Haavard Skinnemoen <haavard.skinnemoen@atmel.com> | 2008-05-19 09:36:28 (GMT) |
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committer | Haavard Skinnemoen <haavard.skinnemoen@atmel.com> | 2008-05-27 13:27:31 (GMT) |
commit | a23e277c4a3a2bbc42d237aae29da3a8971e757f (patch) | |
tree | 22e2e0bc2559d38166e1d1844c9a8ac0429b0475 /cpu/at32ap/hsdramc.c | |
parent | 95107b7c028806919630bf02c653aa8f4f867c94 (diff) | |
download | u-boot-a23e277c4a3a2bbc42d237aae29da3a8971e757f.tar.xz |
avr32: Rework SDRAM initialization code
This cleans up the SDRAM initialization and related code a bit, and
allows faster booting.
* Add definitions for EBI and internal SRAM to asm/arch/memory-map.h
* Remove memory test from sdram_init() and make caller responsible
for verifying the SDRAM and determining its size.
* Remove base_address member from struct sdram_config (was sdram_info)
* Add data_bits member to struct sdram_config and kill CFG_SDRAM_16BIT
* Add support for a common STK1000 hack: 16MB SDRAM instead of 8.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Diffstat (limited to 'cpu/at32ap/hsdramc.c')
-rw-r--r-- | cpu/at32ap/hsdramc.c | 102 |
1 files changed, 39 insertions, 63 deletions
diff --git a/cpu/at32ap/hsdramc.c b/cpu/at32ap/hsdramc.c index 1fcfe75..992612b 100644 --- a/cpu/at32ap/hsdramc.c +++ b/cpu/at32ap/hsdramc.c @@ -30,39 +30,32 @@ #include "hsdramc1.h" -unsigned long sdram_init(const struct sdram_info *info) +unsigned long sdram_init(void *sdram_base, const struct sdram_config *config) { - unsigned long *sdram = (unsigned long *)uncached(info->phys_addr); unsigned long sdram_size; - unsigned long tmp; - unsigned long bus_hz; + uint32_t cfgreg; unsigned int i; - if (!info->refresh_period) - panic("ERROR: SDRAM refresh period == 0. " - "Please update the board code\n"); - - tmp = (HSDRAMC1_BF(NC, info->col_bits - 8) - | HSDRAMC1_BF(NR, info->row_bits - 11) - | HSDRAMC1_BF(NB, info->bank_bits - 1) - | HSDRAMC1_BF(CAS, info->cas) - | HSDRAMC1_BF(TWR, info->twr) - | HSDRAMC1_BF(TRC, info->trc) - | HSDRAMC1_BF(TRP, info->trp) - | HSDRAMC1_BF(TRCD, info->trcd) - | HSDRAMC1_BF(TRAS, info->tras) - | HSDRAMC1_BF(TXSR, info->txsr)); - -#ifdef CFG_SDRAM_16BIT - tmp |= HSDRAMC1_BIT(DBW); - sdram_size = 1 << (info->row_bits + info->col_bits - + info->bank_bits + 1); -#else - sdram_size = 1 << (info->row_bits + info->col_bits - + info->bank_bits + 2); -#endif - - hsdramc1_writel(CR, tmp); + cfgreg = (HSDRAMC1_BF(NC, config->col_bits - 8) + | HSDRAMC1_BF(NR, config->row_bits - 11) + | HSDRAMC1_BF(NB, config->bank_bits - 1) + | HSDRAMC1_BF(CAS, config->cas) + | HSDRAMC1_BF(TWR, config->twr) + | HSDRAMC1_BF(TRC, config->trc) + | HSDRAMC1_BF(TRP, config->trp) + | HSDRAMC1_BF(TRCD, config->trcd) + | HSDRAMC1_BF(TRAS, config->tras) + | HSDRAMC1_BF(TXSR, config->txsr)); + + if (config->data_bits == SDRAM_DATA_16BIT) + cfgreg |= HSDRAMC1_BIT(DBW); + + hsdramc1_writel(CR, cfgreg); + + /* Send a NOP to turn on the clock (necessary on some chips) */ + hsdramc1_writel(MR, HSDRAMC1_MODE_NOP); + hsdramc1_readl(MR); + writel(0, sdram_base); /* * Initialization sequence for SDRAM, from the data sheet: @@ -77,7 +70,7 @@ unsigned long sdram_init(const struct sdram_info *info) */ hsdramc1_writel(MR, HSDRAMC1_MODE_BANKS_PRECHARGE); hsdramc1_readl(MR); - writel(0, sdram); + writel(0, sdram_base); /* * 3. Eight auto-refresh (CBR) cycles are provided @@ -85,58 +78,41 @@ unsigned long sdram_init(const struct sdram_info *info) hsdramc1_writel(MR, HSDRAMC1_MODE_AUTO_REFRESH); hsdramc1_readl(MR); for (i = 0; i < 8; i++) - writel(0, sdram); + writel(0, sdram_base); /* * 4. A mode register set (MRS) cycle is issued to program * SDRAM parameters, in particular CAS latency and burst * length. * - * CAS from info struct, burst length 1, serial burst type + * The address will be chosen by the SDRAMC automatically; we + * just have to make sure BA[1:0] are set to 0. */ hsdramc1_writel(MR, HSDRAMC1_MODE_LOAD_MODE); hsdramc1_readl(MR); - writel(0, sdram + (info->cas << 4)); + writel(0, sdram_base); /* - * 5. A Normal Mode command is provided, 3 clocks after tMRD - * is met. - * - * From the timing diagram, it looks like tMRD is 3 - * cycles...try a dummy read from the peripheral bus. + * 5. The application must go into Normal Mode, setting Mode + * to 0 in the Mode Register and performing a write access + * at any location in the SDRAM. */ - hsdramc1_readl(MR); hsdramc1_writel(MR, HSDRAMC1_MODE_NORMAL); hsdramc1_readl(MR); - writel(0, sdram); + writel(0, sdram_base); /* * 6. Write refresh rate into SDRAMC refresh timer count * register (refresh rate = timing between refresh cycles). - * - * 15.6 us is a typical value for a burst of length one */ - bus_hz = get_sdram_clk_rate(); - hsdramc1_writel(TR, info->refresh_period); - - printf("SDRAM: %u MB at address 0x%08lx\n", - sdram_size >> 20, info->phys_addr); - - printf("Testing SDRAM..."); - for (i = 0; i < sdram_size / 4; i++) - sdram[i] = i; - - for (i = 0; i < sdram_size / 4; i++) { - tmp = sdram[i]; - if (tmp != i) { - printf("FAILED at address 0x%08lx\n", - info->phys_addr + i * 4); - printf("SDRAM: read 0x%lx, expected 0x%lx\n", tmp, i); - return 0; - } - } - - puts("OK\n"); + hsdramc1_writel(TR, config->refresh_period); + + if (config->data_bits == SDRAM_DATA_16BIT) + sdram_size = 1 << (config->row_bits + config->col_bits + + config->bank_bits + 1); + else + sdram_size = 1 << (config->row_bits + config->col_bits + + config->bank_bits + 2); return sdram_size; } |