mpc85xx: Base emulator support

Prepare for emulator support for mpc85xx parts.
Disable DDR training and skip wrlvl_cntl_2 and wrlvl_cntl_3 registers.
These two registers improve stability but not supported by emulator.
Add CONFIG_FSL_TBCLK_EXTRA_DIV for possible adjustment to time base.

Signed-off-by: York Sun <yorksun@freescale.com>

README

@@ -413,6 +413,10 @@ The following options need to be configured:
 		CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
 		This value denotes start offset of DSP CCSR space.
 
+		CONFIG_SYS_FSL_DDR_EMU
+		Specify emulator support for DDR. Some DDR features such as
+		deskew training are not available.
+
 - Generic CPU options:
 		CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
 

arch/powerpc/cpu/mpc85xx/cpu_init.c

@@ -532,8 +532,10 @@ skip_l2:
 
 	enable_cpc();
 
+#ifndef CONFIG_SYS_FSL_NO_SERDES
 	/* needs to be in ram since code uses global static vars */
 	fsl_serdes_init();
+#endif
 
 #ifdef CONFIG_SYS_FSL_ERRATUM_A005871
 	if (IS_SVR_REV(svr, 1, 0)) {

arch/powerpc/cpu/mpc85xx/ddr-gen3.c

@@ -123,10 +123,17 @@ void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
 	out_be32(&ddr->timing_cfg_5, regs->timing_cfg_5);
 	out_be32(&ddr->ddr_zq_cntl, regs->ddr_zq_cntl);
 	out_be32(&ddr->ddr_wrlvl_cntl, regs->ddr_wrlvl_cntl);
+#ifndef CONFIG_SYS_FSL_DDR_EMU
+	/*
+	 * Skip these two registers if running on emulator
+	 * because emulator doesn't have skew between bytes.
+	 */
+
 	if (regs->ddr_wrlvl_cntl_2)
 		out_be32(&ddr->ddr_wrlvl_cntl_2, regs->ddr_wrlvl_cntl_2);
 	if (regs->ddr_wrlvl_cntl_3)
 		out_be32(&ddr->ddr_wrlvl_cntl_3, regs->ddr_wrlvl_cntl_3);
+#endif
 
 	out_be32(&ddr->ddr_sr_cntr, regs->ddr_sr_cntr);
 	out_be32(&ddr->ddr_sdram_rcw_1, regs->ddr_sdram_rcw_1);

arch/powerpc/cpu/mpc85xx/fdt.c

@@ -604,8 +604,12 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 
 	fdt_add_enet_stashing(blob);
 
+#ifndef CONFIG_FSL_TBCLK_EXTRA_DIV
+#define CONFIG_FSL_TBCLK_EXTRA_DIV 1
+#endif
 	do_fixup_by_prop_u32(blob, "device_type", "cpu", 4,
-		"timebase-frequency", get_tbclk(), 1);
+		"timebase-frequency", get_tbclk() / CONFIG_FSL_TBCLK_EXTRA_DIV,
+		1);
 	do_fixup_by_prop_u32(blob, "device_type", "cpu", 4,
 		"bus-frequency", bd->bi_busfreq, 1);
 	get_sys_info(&sysinfo);

arch/powerpc/cpu/mpc8xxx/ddr/ctrl_regs.c

@@ -1638,5 +1638,10 @@ compute_fsl_memctl_config_regs(const memctl_options_t *popts,
 
 	set_ddr_sdram_rcw(ddr, popts, common_dimm);
 
+#ifdef CONFIG_SYS_FSL_DDR_EMU
+	/* disble DDR training for emulator */
+	ddr->debug[2] = 0x00000400;
+	ddr->debug[4] = 0xff800000;
+#endif
 	return check_fsl_memctl_config_regs(ddr);
 }