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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/sh/drivers/pci/fixups-sdk7786.c
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/sh/drivers/pci/fixups-sdk7786.c')
-rw-r--r--arch/sh/drivers/pci/fixups-sdk7786.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/fixups-sdk7786.c b/arch/sh/drivers/pci/fixups-sdk7786.c
new file mode 100644
index 00000000000..0e18ee33255
--- /dev/null
+++ b/arch/sh/drivers/pci/fixups-sdk7786.c
@@ -0,0 +1,67 @@
+/*
+ * SDK7786 FPGA PCIe mux handling
+ *
+ * Copyright (C) 2010 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) "PCI: " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <mach/fpga.h>
+
+/*
+ * The SDK7786 FPGA supports mangling of most of the slots in some way or
+ * another. Slots 3/4 are special in that only one can be supported at a
+ * time, and both appear on port 3 to the PCI bus scan. Enabling slot 4
+ * (the horizontal edge connector) will disable slot 3 entirely.
+ *
+ * Misconfigurations can be detected through the FPGA via the slot
+ * resistors to determine card presence. Hotplug remains unsupported.
+ */
+static unsigned int slot4en __devinitdata;
+
+char *__devinit pcibios_setup(char *str)
+{
+ if (strcmp(str, "slot4en") == 0) {
+ slot4en = 1;
+ return NULL;
+ }
+
+ return str;
+}
+
+static int __init sdk7786_pci_init(void)
+{
+ u16 data = fpga_read_reg(PCIECR);
+
+ /*
+ * Enable slot #4 if it's been specified on the command line.
+ *
+ * Optionally reroute if slot #4 has a card present while slot #3
+ * does not, regardless of command line value.
+ *
+ * Card presence is logically inverted.
+ */
+ slot4en ?: (!(data & PCIECR_PRST4) && (data & PCIECR_PRST3));
+ if (slot4en) {
+ pr_info("Activating PCIe slot#4 (disabling slot#3)\n");
+
+ data &= ~PCIECR_PCIEMUX1;
+ fpga_write_reg(data, PCIECR);
+
+ /* Warn about forced rerouting if slot#3 is occupied */
+ if ((data & PCIECR_PRST3) == 0) {
+ pr_warning("Unreachable card detected in slot#3\n");
+ return -EBUSY;
+ }
+ } else
+ pr_info("PCIe slot#4 disabled\n");
+
+ return 0;
+}
+postcore_initcall(sdk7786_pci_init);