powerpc/mpc85xx: Add DSP side awareness for Freescale Heterogeneous SoCs

The code provides framework for heterogeneous multicore chips based on StarCore
and Power Architecture which are chasis-2 compliant, like B4860 and B4420

It will make u-boot recognize all non-ppc cores and peripherals like
SC3900/DSP CPUs, MAPLE, CPRI and print their configuration in u-boot logs.
Example boot logs of B4860QDS:

U-Boot 2015.01-00232-geef6e36-dirty (Jan 19 2015 - 11:58:45)

CPU0:  B4860E, Version: 2.2, (0x86880022)
Core:  e6500, Version: 2.0, (0x80400120)
Clock Configuration:
       CPU0:1600 MHz, CPU1:1600 MHz, CPU2:1600 MHz, CPU3:1600 MHz,
       DSP CPU0:1200 MHz, DSP CPU1:1200 MHz, DSP CPU2:1200 MHz, DSP CPU3:1200 MHz,
       DSP CPU4:1200 MHz, DSP CPU5:1200 MHz,
       CCB:666.667 MHz,
       DDR:933.333 MHz (1866.667 MT/s data rate) (Asynchronous), IFC:166.667 MHz
       CPRI:600  MHz
       MAPLE:600  MHz, MAPLE-ULB:800  MHz, MAPLE-eTVPE:1000 MHz
       FMAN1: 666.667 MHz
       QMAN:  333.333 MHz

Top level changes include:
(1) Top level CONFIG to identify HETEROGENUOUS clusters
(2) CONFIGS for SC3900/DSP components
(3) Global structures like "cpu_type" and "MPC85xx_SYS_INFO"
    updated for dsp cores and other components
(3) APIs to get DSP num cores and their Mask like:
        cpu_dsp_mask, cpu_num_dspcores etc same as that of PowerPC
(5) Code to fetch and print SC cores and other heterogenous
    device's frequencies
(6) README added for the same

Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/arch/powerpc/cpu/mpc8xxx/cpu.c b/arch/powerpc/cpu/mpc8xxx/cpu.c
index c92589f..584f3b8 100644
--- a/arch/powerpc/cpu/mpc8xxx/cpu.c
+++ b/arch/powerpc/cpu/mpc8xxx/cpu.c
@@ -133,6 +133,53 @@
 	return mask;
 }
 
+#ifdef CONFIG_HETROGENOUS_CLUSTERS
+u32 compute_dsp_cpumask(void)
+{
+	ccsr_gur_t *gur = (void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
+	int i = CONFIG_DSP_CLUSTER_START, count = 0;
+	u32 cluster, type, dsp_mask = 0;
+
+	do {
+		int j;
+		cluster = in_be32(&gur->tp_cluster[i].lower);
+		for (j = 0; j < TP_INIT_PER_CLUSTER; j++) {
+			type = init_type(cluster, j);
+			if (type) {
+				if (TP_ITYP_TYPE(type) == TP_ITYP_TYPE_SC)
+					dsp_mask |= 1 << count;
+				count++;
+			}
+		}
+		i++;
+	} while ((cluster & TP_CLUSTER_EOC) != TP_CLUSTER_EOC);
+
+	return dsp_mask;
+}
+
+int fsl_qoriq_dsp_core_to_cluster(unsigned int core)
+{
+	ccsr_gur_t *gur = (void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
+	int count = 0, i = CONFIG_DSP_CLUSTER_START;
+	u32 cluster;
+
+	do {
+		int j;
+		cluster = in_be32(&gur->tp_cluster[i].lower);
+		for (j = 0; j < TP_INIT_PER_CLUSTER; j++) {
+			if (init_type(cluster, j)) {
+				if (count == core)
+					return i;
+				count++;
+			}
+		}
+		i++;
+	} while ((cluster & TP_CLUSTER_EOC) != TP_CLUSTER_EOC);
+
+	return -1;	/* cannot identify the cluster */
+}
+#endif
+
 int fsl_qoriq_core_to_cluster(unsigned int core)
 {
 	ccsr_gur_t *gur = (void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
@@ -198,8 +245,43 @@
 	return cpu->mask;
 }
 
+#ifdef CONFIG_HETROGENOUS_CLUSTERS
+__weak u32 cpu_dsp_mask(void)
+{
+	ccsr_pic_t __iomem *pic = (void *)CONFIG_SYS_MPC8xxx_PIC_ADDR;
+	struct cpu_type *cpu = gd->arch.cpu;
+
+	/* better to query feature reporting register than just assume 1 */
+	if (cpu == &cpu_type_unknown)
+		return ((in_be32(&pic->frr) & MPC8xxx_PICFRR_NCPU_MASK) >>
+			 MPC8xxx_PICFRR_NCPU_SHIFT) + 1;
+
+	if (cpu->dsp_num_cores == 0)
+		return compute_dsp_cpumask();
+
+	return cpu->dsp_mask;
+}
+
 /*
- * Return the number of cores on this SOC.
+ * Return the number of SC/DSP cores on this SOC.
+ */
+__weak int cpu_num_dspcores(void)
+{
+	struct cpu_type *cpu = gd->arch.cpu;
+
+	/*
+	 * Report # of cores in terms of the cpu_mask if we haven't
+	 * figured out how many there are yet
+	 */
+	if (cpu->dsp_num_cores == 0)
+		return hweight32(cpu_dsp_mask());
+
+	return cpu->dsp_num_cores;
+}
+#endif
+
+/*
+ * Return the number of PPC cores on this SOC.
  */
 __weak int cpu_numcores(void)
 {
@@ -215,6 +297,7 @@
 	return cpu->num_cores;
 }
 
+
 /*
  * Check if the given core ID is valid
  *
@@ -248,6 +331,12 @@
 		cpu->num_cores = cpu_numcores();
 	}
 
+#ifdef CONFIG_HETROGENOUS_CLUSTERS
+	if (cpu->dsp_num_cores == 0) {
+		cpu->dsp_mask = cpu_dsp_mask();
+		cpu->dsp_num_cores = cpu_num_dspcores();
+	}
+#endif
 	return 0;
 }