powerpc/mpc85xx: Add workaround to enable TDM on T1040

This is a workaround for 32 bit hardware limitation of TDM.
T1040 has 36 bit physical addressing, TDM DMAC register
are 32 bit wide but need to store address of CCSR space
which lies beyond 32 bit address range. This workaround
creats a LAW to enable access of TDM DMA to CCSR by
mapping CCSR to overlap with DDR.
A hole of 16M is created in memory using device tree. This
workaround law is set only if "tdm" is defined in hwconfig.
Also disable POST tests and add LIODN for TDM

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

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/powerpc/cpu/mpc85xx/fdt.c b/arch/powerpc/cpu/mpc85xx/fdt.c
index ed80a84180..85dfa5bc01 100644
--- a/arch/powerpc/cpu/mpc85xx/fdt.c
+++ b/arch/powerpc/cpu/mpc85xx/fdt.c
@@ -14,6 +14,7 @@
 #include <linux/ctype.h>
 #include <asm/io.h>
 #include <asm/fsl_portals.h>
+#include <hwconfig.h>
 #ifdef CONFIG_FSL_ESDHC
 #include <fsl_esdhc.h>
 #endif
@@ -35,6 +36,11 @@ void ft_fixup_cpu(void *blob, u64 memory_limit)
 	u32 bootpg = determine_mp_bootpg(NULL);
 	u32 id = get_my_id();
 	const char *enable_method;
+#if defined(T1040_TDM_QUIRK_CCSR_BASE)
+	int ret;
+	int tdm_hwconfig_enabled = 0;
+	char buffer[HWCONFIG_BUFFER_SIZE] = {0};
+#endif
 
 	off = fdt_node_offset_by_prop_value(blob, -1, "device_type", "cpu", 4);
 	while (off != -FDT_ERR_NOTFOUND) {
@@ -77,6 +83,26 @@ void ft_fixup_cpu(void *blob, u64 memory_limit)
 				"device_type", "cpu", 4);
 	}
 
+#if defined(T1040_TDM_QUIRK_CCSR_BASE)
+#define	CONFIG_MEM_HOLE_16M	0x1000000
+	/*
+	 * Extract hwconfig from environment.
+	 * Search for tdm entry in hwconfig.
+	 */
+	ret = getenv_f("hwconfig", buffer, sizeof(buffer));
+	if (ret > 0)
+		tdm_hwconfig_enabled = hwconfig_f("tdm", buffer);
+
+	/* Reserve the memory hole created by TDM LAW, so OSes dont use it */
+	if (tdm_hwconfig_enabled) {
+		off = fdt_add_mem_rsv(blob, T1040_TDM_QUIRK_CCSR_BASE,
+				      CONFIG_MEM_HOLE_16M);
+		if (off < 0)
+			printf("Failed  to reserve memory for tdm: %s\n",
+			       fdt_strerror(off));
+	}
+#endif
+
 	/* Reserve the boot page so OSes dont use it */
 	if ((u64)bootpg < memory_limit) {
 		off = fdt_add_mem_rsv(blob, bootpg, (u64)4096);