mpc85xx: Add support for the Varisys Cyrus board

This board runs a P5020 or P5040 chip, and utilizes
an EEPROM with similar formatting to the Freescale P5020DS.

Large amounts of this code were developed by
Adrian Cox <adrian at humboldt dot co dot uk>

Signed-off-by: Andy Fleming <afleming@gmail.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/board/varisys/cyrus/ddr.c b/board/varisys/cyrus/ddr.c
new file mode 100644
index 0000000..bb1d29a
--- /dev/null
+++ b/board/varisys/cyrus/ddr.c
@@ -0,0 +1,188 @@
+/*
+ * Based on corenet_ds ddr code
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <hwconfig.h>
+#include <asm/mmu.h>
+#include <fsl_ddr_sdram.h>
+#include <fsl_ddr_dimm_params.h>
+#include <asm/fsl_law.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+
+struct board_specific_parameters {
+	u32 n_ranks;
+	u32 datarate_mhz_high;
+	u32 clk_adjust;
+	u32 wrlvl_start;
+	u32 cpo;
+	u32 write_data_delay;
+	u32 force_2t;
+};
+
+/*
+ * This table contains all valid speeds we want to override with board
+ * specific parameters. datarate_mhz_high values need to be in ascending order
+ * for each n_ranks group.
+ */
+static const struct board_specific_parameters udimm0[] = {
+	/*
+	 * memory controller 0
+	 *   num|  hi|  clk| wrlvl | cpo  |wrdata|2T
+	 * ranks| mhz|adjst| start |      |delay |
+	 */
+	{4,   850,    4,     6,   0xff,    2,  0},
+	{4,   950,    5,     7,   0xff,    2,  0},
+	{4,  1050,    5,     8,   0xff,    2,  0},
+	{4,  1250,    5,    10,   0xff,    2,  0},
+	{4,  1350,    5,    11,   0xff,    2,  0},
+	{4,  1666,    5,    12,   0xff,    2,  0},
+	{2,   850,    5,     6,   0xff,    2,  0},
+	{2,  1050,    5,     7,   0xff,    2,  0},
+	{2,  1250,    4,     6,   0xff,    2,  0},
+	{2,  1350,    5,     7,   0xff,    2,  0},
+	{2,  1666,    5,     8,   0xff,    2,  0},
+	{1,  1250,    4,     6,   0xff,    2,  0},
+	{1,  1335,    4,     7,   0xff,    2,  0},
+	{1,  1666,    4,     8,   0xff,    2,  0},
+	{}
+};
+
+/*
+ * The two slots have slightly different timing. The center values are good
+ * for both slots. We use identical speed tables for them. In future use, if
+ * DIMMs have fewer center values that require two separated tables, copy the
+ * udimm0 table to udimm1 and make changes to clk_adjust and wrlvl_start.
+ */
+static const struct board_specific_parameters *udimms[] = {
+	udimm0,
+	udimm0,
+};
+
+static const struct board_specific_parameters rdimm0[] = {
+	/*
+	 * memory controller 0
+	 *   num|  hi|  clk| wrlvl | cpo  |wrdata|2T
+	 * ranks| mhz|adjst| start |      |delay |
+	 */
+	{4,   850,    4,     6,   0xff,    2,  0},
+	{4,   950,    5,     7,   0xff,    2,  0},
+	{4,  1050,    5,     8,   0xff,    2,  0},
+	{4,  1250,    5,    10,   0xff,    2,  0},
+	{4,  1350,    5,    11,   0xff,    2,  0},
+	{4,  1666,    5,    12,   0xff,    2,  0},
+	{2,   850,    4,     6,   0xff,    2,  0},
+	{2,  1050,    4,     7,   0xff,    2,  0},
+	{2,  1666,    4,     8,   0xff,    2,  0},
+	{1,   850,    4,     5,   0xff,    2,  0},
+	{1,   950,    4,     7,   0xff,    2,  0},
+	{1,  1666,    4,     8,   0xff,    2,  0},
+	{}
+};
+
+/*
+ * The two slots have slightly different timing. See comments above.
+ */
+static const struct board_specific_parameters *rdimms[] = {
+	rdimm0,
+	rdimm0,
+};
+
+void fsl_ddr_board_options(memctl_options_t *popts,
+				dimm_params_t *pdimm,
+				unsigned int ctrl_num)
+{
+	const struct board_specific_parameters *pbsp, *pbsp_highest = NULL;
+	ulong ddr_freq;
+
+	if (ctrl_num > 1) {
+		printf("Wrong parameter for controller number %d", ctrl_num);
+		return;
+	}
+	if (!pdimm->n_ranks)
+		return;
+
+	if (popts->registered_dimm_en)
+		pbsp = rdimms[ctrl_num];
+	else
+		pbsp = udimms[ctrl_num];
+
+
+	/* Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
+	 * freqency and n_banks specified in board_specific_parameters table.
+	 */
+	ddr_freq = get_ddr_freq(0) / 1000000;
+	while (pbsp->datarate_mhz_high) {
+		if (pbsp->n_ranks == pdimm->n_ranks) {
+			if (ddr_freq <= pbsp->datarate_mhz_high) {
+				popts->cpo_override = pbsp->cpo;
+				popts->write_data_delay =
+					pbsp->write_data_delay;
+				popts->clk_adjust = pbsp->clk_adjust;
+				popts->wrlvl_start = pbsp->wrlvl_start;
+				popts->twot_en = pbsp->force_2t;
+				goto found;
+			}
+			pbsp_highest = pbsp;
+		}
+		pbsp++;
+	}
+
+	if (pbsp_highest) {
+		printf("Error: board specific timing not found for data rate %lu MT/s!\nTrying to use the highest speed (%u) parameters\n",
+			ddr_freq, pbsp_highest->datarate_mhz_high);
+		popts->cpo_override = pbsp_highest->cpo;
+		popts->write_data_delay = pbsp_highest->write_data_delay;
+		popts->clk_adjust = pbsp_highest->clk_adjust;
+		popts->wrlvl_start = pbsp_highest->wrlvl_start;
+		popts->twot_en = pbsp_highest->force_2t;
+	} else {
+		panic("DIMM is not supported by this board");
+	}
+found:
+	/*
+	 * Factors to consider for half-strength driver enable:
+	 *	- number of DIMMs installed
+	 */
+	popts->half_strength_driver_enable = 0;
+	/*
+	 * Write leveling override
+	 */
+	popts->wrlvl_override = 1;
+	popts->wrlvl_sample = 0xf;
+
+	/*
+	 * Rtt and Rtt_WR override
+	 */
+	popts->rtt_override = 0;
+
+	/* Enable ZQ calibration */
+	popts->zq_en = 1;
+
+	/* DHC_EN =1, ODT = 60 Ohm */
+	popts->ddr_cdr1 = DDR_CDR1_DHC_EN;
+}
+
+phys_size_t initdram(int board_type)
+{
+	phys_size_t dram_size;
+
+	puts("Initializing....");
+
+	if (!fsl_use_spd())
+		panic("Cyrus only supports using SPD for DRAM\n");
+
+	puts("using SPD\n");
+	dram_size = fsl_ddr_sdram();
+
+	dram_size = setup_ddr_tlbs(dram_size / 0x100000);
+	dram_size *= 0x100000;
+
+	debug("    DDR: ");
+	return dram_size;
+}