[ARM] Kirkwood: enable PCIe before reading device ID register
PCIe may have been disabled (by kirkwood_clock_gate)
if this kernel was started by kexec. Make sure PCIe
is enabled before attempting to access the device ID
register, otherwise the system will hang.
Signed-off-by: Eric Cooper <ecc@cmu.edu>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
diff --git a/arch/arm/mach-kirkwood/pcie.c b/arch/arm/mach-kirkwood/pcie.c
index 513ad31..ca294ff 100644
--- a/arch/arm/mach-kirkwood/pcie.c
+++ b/arch/arm/mach-kirkwood/pcie.c
@@ -18,8 +18,16 @@
#include <mach/bridge-regs.h>
#include "common.h"
+void kirkwood_enable_pcie(void)
+{
+ u32 curr = readl(CLOCK_GATING_CTRL);
+ if (!(curr & CGC_PEX0))
+ writel(curr | CGC_PEX0, CLOCK_GATING_CTRL);
+}
+
void __init kirkwood_pcie_id(u32 *dev, u32 *rev)
{
+ kirkwood_enable_pcie();
*dev = orion_pcie_dev_id((void __iomem *)PCIE_VIRT_BASE);
*rev = orion_pcie_rev((void __iomem *)PCIE_VIRT_BASE);
}