MIPS: Lantiq: Add PCI controller support.
The Lantiq family of SoCs have a EBU (External Bus Unit). This patch adds
the driver that allows us to use the EBU as a PCI controller. In order for
PCI to work the EBU is set to endianess swap all the data. In addition we
need to make use of SWAP_IO_SPACE for device->host DMA to work.
The clock of the PCI works in several modes (internal/external). If this
is not configured correctly the SoC will hang.
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2250/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pci/ops-lantiq.c b/arch/mips/pci/ops-lantiq.c
new file mode 100644
index 0000000..1f2afb5
--- /dev/null
+++ b/arch/mips/pci/ops-lantiq.c
@@ -0,0 +1,116 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/mm.h>
+#include <asm/addrspace.h>
+#include <linux/vmalloc.h>
+
+#include <lantiq_soc.h>
+
+#include "pci-lantiq.h"
+
+#define LTQ_PCI_CFG_BUSNUM_SHF 16
+#define LTQ_PCI_CFG_DEVNUM_SHF 11
+#define LTQ_PCI_CFG_FUNNUM_SHF 8
+
+#define PCI_ACCESS_READ 0
+#define PCI_ACCESS_WRITE 1
+
+static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus,
+ unsigned int devfn, unsigned int where, u32 *data)
+{
+ unsigned long cfg_base;
+ unsigned long flags;
+ u32 temp;
+
+ /* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the
+ SoC itself */
+ if ((bus->number != 0) || ((devfn & 0xf8) > 0x78)
+ || ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68))
+ return 1;
+
+ spin_lock_irqsave(&ebu_lock, flags);
+
+ cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+ cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn <<
+ LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3);
+
+ /* Perform access */
+ if (access_type == PCI_ACCESS_WRITE) {
+ ltq_w32(swab32(*data), ((u32 *)cfg_base));
+ } else {
+ *data = ltq_r32(((u32 *)(cfg_base)));
+ *data = swab32(*data);
+ }
+ wmb();
+
+ /* clean possible Master abort */
+ cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+ cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
+ temp = ltq_r32(((u32 *)(cfg_base)));
+ temp = swab32(temp);
+ cfg_base = (unsigned long) ltq_pci_mapped_cfg;
+ cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4;
+ ltq_w32(temp, ((u32 *)cfg_base));
+
+ spin_unlock_irqrestore(&ebu_lock, flags);
+
+ if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ))
+ return 1;
+
+ return 0;
+}
+
+int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ u32 data = 0;
+
+ if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (size == 1)
+ *val = (data >> ((where & 3) << 3)) & 0xff;
+ else if (size == 2)
+ *val = (data >> ((where & 3) << 3)) & 0xffff;
+ else
+ *val = data;
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ u32 data = 0;
+
+ if (size == 4) {
+ data = val;
+ } else {
+ if (ltq_pci_config_access(PCI_ACCESS_READ, bus,
+ devfn, where, &data))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (size == 1)
+ data = (data & ~(0xff << ((where & 3) << 3))) |
+ (val << ((where & 3) << 3));
+ else if (size == 2)
+ data = (data & ~(0xffff << ((where & 3) << 3))) |
+ (val << ((where & 3) << 3));
+ }
+
+ if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ return PCIBIOS_SUCCESSFUL;
+}