[linux-yocto] [PATCH 149/161] arch/powerpc: Reset Updates for Axxia

[Cristian Bercaru]

From: John Jacques <john.jacques at lsi.com>

Reset support for 3400/2500/3500 got removed when we were porting to
Yocto quite some time back.  It has never worked since that port.
This restores the original reset code require to support reset on 3400/2500/3500.

Signed-off-by: John Jacques <john.jacques at lsi.com>
---
 arch/powerpc/sysdev/ppc4xx_soc.c |   73 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/sysdev/ppc4xx_soc.c b/arch/powerpc/sysdev/ppc4xx_soc.c
index 0debcc3..5505f46 100644
--- a/arch/powerpc/sysdev/ppc4xx_soc.c
+++ b/arch/powerpc/sysdev/ppc4xx_soc.c
@@ -24,6 +24,9 @@
 #include <asm/dcr.h>
 #include <asm/dcr-regs.h>
 #include <asm/reg.h>
+#ifdef CONFIG_ACP
+#include <asm/mpic.h>
+#endif
 
 static u32 dcrbase_l2c;
 
@@ -60,7 +63,7 @@ static irqreturn_t l2c_error_handler(int irq, void *dev)
 	}
 
 	/* Clear parity errors */
-	if (sr & (L2C_SR_CPE | L2C_SR_TPE)){
+	if (sr & (L2C_SR_CPE | L2C_SR_TPE)) {
 		mtdcr(dcrbase_l2c + DCRN_L2C0_ADDR, 0);
 		mtdcr(dcrbase_l2c + DCRN_L2C0_CMD, L2C_CMD_CCP | L2C_CMD_CTE);
 	} else {
@@ -190,6 +193,45 @@ static int __init ppc4xx_l2c_probe(void)
 }
 arch_initcall(ppc4xx_l2c_probe);
 
+#ifdef CONFIG_ACP
+
+/*
+ * Issue a "core" reset.
+ */
+
+void
+acp_jump_to_boot_loader(void *input)
+{
+	mpic_teardown_this_cpu(0);
+	/* This is only valid in the "core" reset case, so 0x10000000. */
+	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | 0x10000000);
+
+	while (1)
+		;		/* Just in case the jump fails. */
+}
+
+/*
+ * Get all other cores to run "acp_jump_to_boot_loader()" then go
+ * there as well.
+ */
+
+void
+acp_reset_cores(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		if (cpu != smp_processor_id())
+			smp_call_function_single(cpu, acp_jump_to_boot_loader,
+						 NULL, 0);
+	}
+
+	acp_jump_to_boot_loader(NULL);
+}
+
+
+#endif
+
 /*
  * Apply a system reset. Alternatively a board specific value may be
  * provided via the "reset-type" property in the cpu node.
@@ -214,7 +256,36 @@ void ppc4xx_reset_system(char *cmd)
 			reset_type = prop[0] << 28;
 	}
 
+#ifdef CONFIG_ACP
+	if (DBCR0_RST_CORE == reset_type) {
+		acp_reset_cores();
+	} else {
+		/*
+		  In this case, reset_type is either chip or system.
+
+		  On the AXM3500 (PVR=0x7ff520c1), writing to DBCR0
+		  will occasionally stall the system.  As a
+		  work-around, write to the system control register.
+		*/
+
+		u32 pvr_value;
+
+		asm volatile ("mfpvr    %0" : "=r"(pvr_value));
+
+		if (0x7ff520c1 == pvr_value) {
+			u32 value;
+
+			value = mfdcrx(0xd0a);
+			value |= 0xab;
+			mtdcrx(0xd0a, value);
+			mtdcrx(0xe00, 1);
+		} else {
+			mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | reset_type);
+		}
+	}
+#else
 	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | reset_type);
+#endif
 
 	while (1)
 		;	/* Just in case the reset doesn't work */
-- 
1.7.9.5