Merge with /home/wd/git/u-boot/mailing-list/Haavard_Skinnemoen

1 files changed, 155 insertions, 0 deletions

diff --git a/cpu/at32ap/hsdramc.c b/cpu/at32ap/hsdramc.c
new file mode 100644
index 0000000..f36da35
--- /dev/null
+++ b/cpu/at32ap/hsdramc.c
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+/*
+ * Copyright (C) 2005-2006 Atmel Corporation
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 <common.h>
+
+#ifdef CFG_HSDRAMC
+#include <asm/io.h>
+#include <asm/sdram.h>
+
+#include <asm/arch/platform.h>
+
+#include "hsdramc1.h"
+
+struct hsdramc {
+	const struct device *hebi;
+	void *regs;
+};
+
+static struct hsdramc hsdramc;
+
+unsigned long sdram_init(const struct sdram_info *info)
+{
+	unsigned long *sdram = (unsigned long *)uncached(info->phys_addr);
+	unsigned long sdram_size;
+	unsigned long tmp;
+	unsigned long bus_hz;
+	unsigned int i;
+
+	hsdramc.hebi = get_device(DEVICE_HEBI);
+	if (!hsdramc.hebi)
+		return 0;
+
+	/* FIXME: Both of these lines are complete hacks */
+	hsdramc.regs = hsdramc.hebi->regs + 0x400;
+	bus_hz = pm_get_clock_freq(hsdramc.hebi->resource[0].u.clock.id);
+
+	cpu_enable_sdram();
+
+	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(&hsdramc, CR, tmp);
+
+	/*
+	 * Initialization sequence for SDRAM, from the data sheet:
+	 *
+	 * 1. A minimum pause of 200 us is provided to precede any
+	 *    signal toggle.
+	 */
+	udelay(200);
+
+	/*
+	 * 2. A Precharge All command is issued to the SDRAM
+	 */
+	hsdramc1_writel(&hsdramc, MR, HSDRAMC1_MODE_BANKS_PRECHARGE);
+	hsdramc1_readl(&hsdramc, MR);
+	writel(0, sdram);
+
+	/*
+	 * 3. Eight auto-refresh (CBR) cycles are provided
+	 */
+	hsdramc1_writel(&hsdramc, MR, HSDRAMC1_MODE_AUTO_REFRESH);
+	hsdramc1_readl(&hsdramc, MR);
+	for (i = 0; i < 8; i++)
+		writel(0, sdram);
+
+	/*
+	 * 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
+	 */
+	hsdramc1_writel(&hsdramc, MR, HSDRAMC1_MODE_LOAD_MODE);
+	hsdramc1_readl(&hsdramc, MR);
+	writel(0, sdram + (info->cas << 4));
+
+	/*
+	 * 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.
+	 */
+	hsdramc1_readl(&hsdramc, MR);
+	hsdramc1_writel(&hsdramc, MR, HSDRAMC1_MODE_NORMAL);
+	hsdramc1_readl(&hsdramc, MR);
+	writel(0, sdram);
+
+	/*
+	 * 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
+	 */
+	hsdramc1_writel(&hsdramc, TR, (156 * (bus_hz / 1000)) / 10000);
+
+	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");
+
+	return sdram_size;
+}
+
+#endif /* CFG_HSDRAMC */