[U-Boot] [PATCH v2] nds32: Enable FPU if the version of CPU supported

[Kuan-Yu Kuo]

Some version of Andes core support FPU coprocessor,
if this is the case, and toolchain support FPU instruction set,
we should enable it at low level initialization time.

Signed-off-by: Kuan-Yu Kuo <ken.kuoky at gmail.com>
Cc: Macpaul Lin <macpaul at gmail.com>
---
Change for v2:
   - Add compile option to determine if current used toolchain support
     FPU instruction or not.

 arch/nds32/cpu/n1213/ag101/lowlevel_init.S |   26 ++++++++++++++++++++++++++
 arch/nds32/cpu/n1213/ag102/lowlevel_init.S |   26 ++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/arch/nds32/cpu/n1213/ag101/lowlevel_init.S b/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
index 55985cf..021de86 100644
--- a/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
+++ b/arch/nds32/cpu/n1213/ag101/lowlevel_init.S
@@ -98,6 +98,11 @@ lowlevel_init:
 	led	0x10
 	jal	remap
 
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+	led	0x1f
+	jal	enable_fpu
+#endif
+
 	led	0x20
 	ret	$r10
 
@@ -234,6 +239,27 @@ relo_base:
 2:
 	ret
 
+	/*
+	 * enable_fpu:
+	 *  Some of Andes CPU version support FPU coprocessor, if so,
+	 *  and toolchain support FPU instruction set, we should enable it.
+	 */
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+enable_fpu:
+	mfsr    $r0, $CPU_VER     /* enable FPU if it exists */
+	srli    $r0, $r0, 3
+	andi    $r0, $r0, 1
+	beqz    $r0, 1f           /* skip if no COP */
+	mfsr    $r0, $FUCOP_EXIST
+	srli    $r0, $r0, 31
+	beqz    $r0, 1f           /* skip if no FPU */
+	mfsr    $r0, $FUCOP_CTL
+	ori     $r0, $r0, 1
+	mtsr    $r0, $FUCOP_CTL
+1:
+	ret
+#endif
+
 .globl show_led
 show_led:
     li      $r8, (CONFIG_DEBUG_LED)
diff --git a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
index d842afa..d3b9e16 100644
--- a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
+++ b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
@@ -114,6 +114,11 @@ lowlevel_init:
 	led	0x20
 	jal	remap
 
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+	led	0x2f
+	jal	enable_fpu
+#endif
+
 	led	0x30
 	ret	$r10
 
@@ -289,6 +294,27 @@ relo_base:
 2:
 	ret
 
+	/*
+	 * enable_fpu:
+	 *  Some of Andes CPU version support FPU coprocessor, if so,
+	 *  and toolchain support FPU instruction set, we should enable it.
+	 */
+#if (defined(NDS32_EXT_FPU_DP) || defined(NDS32_EXT_FPU_SP))
+enable_fpu:
+	mfsr    $r0, $CPU_VER     /* enable FPU if it exists */
+	srli    $r0, $r0, 3
+	andi    $r0, $r0, 1
+	beqz    $r0, 1f           /* skip if no COP */
+	mfsr    $r0, $FUCOP_EXIST
+	srli    $r0, $r0, 31
+	beqz    $r0, 1f           /* skip if no FPU */
+	mfsr    $r0, $FUCOP_CTL
+	ori     $r0, $r0, 1
+	mtsr    $r0, $FUCOP_CTL
+1:
+	ret
+#endif
+
 .globl show_led
 show_led:
     li      $r8, (CONFIG_DEBUG_LED)
-- 
1.7.9.5