ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/arc/plat-axs10x/axs10x.c b/arch/arc/plat-axs10x/axs10x.c
index 99f7da513a48..e7769c3ab5f2 100644
--- a/arch/arc/plat-axs10x/axs10x.c
+++ b/arch/arc/plat-axs10x/axs10x.c
@@ -389,6 +389,21 @@ axs103_set_freq(unsigned int id, unsigned int fd, unsigned int od)
 
 static void __init axs103_early_init(void)
 {
+        /*
+         * AXS103 configurations for SMP/QUAD configurations share device tree
+         * which defaults to 90 MHz. However recent failures of Quad config
+         * revealed P&R timing violations so clamp it down to safe 50 MHz
+         * Instead of duplicating defconfig/DT for SMP/QUAD, add a small hack
+         *
+         * This hack is really hacky as of now. Fix it properly by getting the
+         * number of cores as return value of platform's early SMP callback
+         */
+#ifdef CONFIG_ARC_MCIP
+        unsigned int num_cores = (read_aux_reg(ARC_REG_MCIP_BCR) >> 16) & 0x3F;
+        if (num_cores > 2)
+                arc_set_core_freq(50 * 1000000);
+#endif
+
         switch (arc_get_core_freq()/1000000) {
         case 33:
                 axs103_set_freq(1, 1, 1);