[U-Boot] [PATCH 2/2] axs103: Support slave core kick-start on axs103 v1.1 firmware

[Alexey Brodkin]

In axs103 v1.1 procedure to kick-start slave cores has changed quite a bit
compared t previous implementation.

In particular:
 * We used to have a generic START bit for all cores selected by CORE_SEL
   mask. But now we don't touch CORE_SEL at all because we have a dedicated
   START bit for each core:
     bit 0: Core 0 (master)
     bit 1: Core 1 (slave)
 * Now there's no need to select "manual" mode of core start

Additional challenge for us is how to tell which axs103 firmware we're
dealing with. For now we'll rely on ARC core version which was bumped
from 2.1c to 3.0.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
---
 board/synopsys/axs10x/axs10x.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/board/synopsys/axs10x/axs10x.c b/board/synopsys/axs10x/axs10x.c
index 57c790220f71..912764a3d807 100644
--- a/board/synopsys/axs10x/axs10x.c
+++ b/board/synopsys/axs10x/axs10x.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <dwmmc.h>
 #include <malloc.h>
+#include <asm/arcregs.h>
 #include "axs10x.h"
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -66,9 +67,27 @@ void smp_kick_all_cpus(void)
 #define BITS_START_MODE	4
 #define BITS_CORE_SEL	9
 
+/*
+ * In axs103 v1.1 START bits semantics has changed quite a bit.
+ * We used to have a generic START bit for all cores selected by CORE_SEL mask.
+ * But now we don't touch CORE_SEL at all because we have a dedicated START bit
+ * for each core:
+ *     bit 0: Core 0 (master)
+ *     bit 1: Core 1 (slave)
+ */
+#define BITS_START_CORE1	1
+
+#define ARCVER_HS38_3_0	0x53
+
+	int core_family = read_aux_reg(ARC_AUX_IDENTITY) & 0xff;
 	int cmd = readl((void __iomem *)AXC003_CREG_CPU_START);
-	cmd |= (1 << BITS_CORE_SEL) | (1 << BITS_START);
-	cmd &= ~(1 << BITS_START_MODE);
+
+	if (core_family < ARCVER_HS38_3_0) {
+		cmd |= (1 << BITS_CORE_SEL) | (1 << BITS_START);
+		cmd &= ~(1 << BITS_START_MODE);
+	} else {
+		cmd |= (1 << BITS_START_CORE1);
+	}
 	writel(cmd, (void __iomem *)AXC003_CREG_CPU_START);
 }
 #endif
-- 
2.7.4