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, 29 insertions, 0 deletions

diff --git a/arch/powerpc/cpu/mpc85xx/cpu_init.c b/arch/powerpc/cpu/mpc85xx/cpu_init.c
index d6cf88555a..78316a6815 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu_init.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu_init.c
@@ -225,6 +225,32 @@ static void disable_cpc_sram(void)
 }
 #endif
 
+#if defined(T1040_TDM_QUIRK_CCSR_BASE)
+#ifdef CONFIG_POST
+#error POST memory test cannot be enabled with TDM
+#endif
+static void enable_tdm_law(void)
+{
+	int ret;
+	char buffer[HWCONFIG_BUFFER_SIZE] = {0};
+	int tdm_hwconfig_enabled = 0;
+
+	/*
+	 * Extract hwconfig from environment since environment
+	 * is not setup properly yet. Search for tdm entry in
+	 * hwconfig.
+	 */
+	ret = getenv_f("hwconfig", buffer, sizeof(buffer));
+	if (ret > 0) {
+		tdm_hwconfig_enabled = hwconfig_f("tdm", buffer);
+		/* If tdm is defined in hwconfig, set law for tdm workaround */
+		if (tdm_hwconfig_enabled)
+			set_next_law(T1040_TDM_QUIRK_CCSR_BASE, LAW_SIZE_16M,
+				     LAW_TRGT_IF_CCSR);
+	}
+}
+#endif
+
 static void enable_cpc(void)
 {
 	int i;
@@ -729,6 +755,9 @@ skip_l2:
 	disable_cpc_sram();
 #endif
 	enable_cpc();
+#if defined(T1040_TDM_QUIRK_CCSR_BASE)
+	enable_tdm_law();
+#endif
 
 #ifndef CONFIG_SYS_FSL_NO_SERDES
 	/* needs to be in ram since code uses global static vars */