summaryrefslogtreecommitdiffstats
path: root/arch/mips/pci/pci-bcm1480ht.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/pci/pci-bcm1480ht.c')
-rw-r--r--arch/mips/pci/pci-bcm1480ht.c203
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/mips/pci/pci-bcm1480ht.c b/arch/mips/pci/pci-bcm1480ht.c
new file mode 100644
index 000000000..3d996acd2
--- /dev/null
+++ b/arch/mips/pci/pci-bcm1480ht.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2001,2002,2005 Broadcom Corporation
+ * Copyright (C) 2004 by Ralf Baechle (ralf@linux-mips.org)
+ */
+
+/*
+ * BCM1480/1455-specific HT support (looking like PCI)
+ *
+ * This module provides the glue between Linux's PCI subsystem
+ * and the hardware. We basically provide glue for accessing
+ * configuration space, and set up the translation for I/O
+ * space accesses.
+ *
+ * To access configuration space, we use ioremap. In the 32-bit
+ * kernel, this consumes either 4 or 8 page table pages, and 16MB of
+ * kernel mapped memory. Hopefully neither of these should be a huge
+ * problem.
+ *
+ */
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_scd.h>
+#include <asm/sibyte/board.h>
+#include <asm/io.h>
+
+/*
+ * Macros for calculating offsets into config space given a device
+ * structure or dev/fun/reg
+ */
+#define CFGOFFSET(bus, devfn, where) (((bus)<<16)+((devfn)<<8)+(where))
+#define CFGADDR(bus, devfn, where) CFGOFFSET((bus)->number, (devfn), where)
+
+static void *ht_cfg_space;
+
+#define PCI_BUS_ENABLED 1
+#define PCI_DEVICE_MODE 2
+
+static int bcm1480ht_bus_status;
+
+#define PCI_BRIDGE_DEVICE 0
+#define HT_BRIDGE_DEVICE 1
+
+/*
+ * HT's level-sensitive interrupts require EOI, which is generated
+ * through a 4MB memory-mapped region
+ */
+unsigned long ht_eoi_space;
+
+/*
+ * Read/write 32-bit values in config space.
+ */
+static inline u32 READCFG32(u32 addr)
+{
+ return *(u32 *)(ht_cfg_space + (addr&~3));
+}
+
+static inline void WRITECFG32(u32 addr, u32 data)
+{
+ *(u32 *)(ht_cfg_space + (addr & ~3)) = data;
+}
+
+/*
+ * Some checks before doing config cycles:
+ * In PCI Device Mode, hide everything on bus 0 except the LDT host
+ * bridge. Otherwise, access is controlled by bridge MasterEn bits.
+ */
+static int bcm1480ht_can_access(struct pci_bus *bus, int devfn)
+{
+ u32 devno;
+
+ if (!(bcm1480ht_bus_status & (PCI_BUS_ENABLED | PCI_DEVICE_MODE)))
+ return 0;
+
+ if (bus->number == 0) {
+ devno = PCI_SLOT(devfn);
+ if (bcm1480ht_bus_status & PCI_DEVICE_MODE)
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * Read/write access functions for various sizes of values
+ * in config space. Return all 1's for disallowed accesses
+ * for a kludgy but adequate simulation of master aborts.
+ */
+
+static int bcm1480ht_pcibios_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 * val)
+{
+ u32 data = 0;
+
+ if ((size == 2) && (where & 1))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ else if ((size == 4) && (where & 3))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ if (bcm1480ht_can_access(bus, devfn))
+ data = READCFG32(CFGADDR(bus, devfn, where));
+ else
+ data = 0xFFFFFFFF;
+
+ 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;
+}
+
+static int bcm1480ht_pcibios_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ u32 cfgaddr = CFGADDR(bus, devfn, where);
+ u32 data = 0;
+
+ if ((size == 2) && (where & 1))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ else if ((size == 4) && (where & 3))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ if (!bcm1480ht_can_access(bus, devfn))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ data = READCFG32(cfgaddr);
+
+ 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));
+ else
+ data = val;
+
+ WRITECFG32(cfgaddr, data);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int bcm1480ht_pcibios_get_busno(void)
+{
+ return 0;
+}
+
+struct pci_ops bcm1480ht_pci_ops = {
+ .read = bcm1480ht_pcibios_read,
+ .write = bcm1480ht_pcibios_write,
+};
+
+static struct resource bcm1480ht_mem_resource = {
+ .name = "BCM1480 HT MEM",
+ .start = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES,
+ .end = A_BCM1480_PHYS_HT_MEM_MATCH_BYTES + 0x1fffffffUL,
+ .flags = IORESOURCE_MEM,
+};
+
+static struct resource bcm1480ht_io_resource = {
+ .name = "BCM1480 HT I/O",
+ .start = A_BCM1480_PHYS_HT_IO_MATCH_BYTES,
+ .end = A_BCM1480_PHYS_HT_IO_MATCH_BYTES + 0x01ffffffUL,
+ .flags = IORESOURCE_IO,
+};
+
+struct pci_controller bcm1480ht_controller = {
+ .pci_ops = &bcm1480ht_pci_ops,
+ .mem_resource = &bcm1480ht_mem_resource,
+ .io_resource = &bcm1480ht_io_resource,
+ .index = 1,
+ .get_busno = bcm1480ht_pcibios_get_busno,
+ .io_offset = A_BCM1480_PHYS_HT_IO_MATCH_BYTES,
+};
+
+static int __init bcm1480ht_pcibios_init(void)
+{
+ ht_cfg_space = ioremap(A_BCM1480_PHYS_HT_CFG_MATCH_BITS, 16*1024*1024);
+
+ /* CFE doesn't always init all HT paths, so we always scan */
+ bcm1480ht_bus_status |= PCI_BUS_ENABLED;
+
+ ht_eoi_space = (unsigned long)
+ ioremap(A_BCM1480_PHYS_HT_SPECIAL_MATCH_BYTES,
+ 4 * 1024 * 1024);
+ bcm1480ht_controller.io_map_base = (unsigned long)
+ ioremap(A_BCM1480_PHYS_HT_IO_MATCH_BYTES, 65536);
+ bcm1480ht_controller.io_map_base -= bcm1480ht_controller.io_offset;
+
+ register_pci_controller(&bcm1480ht_controller);
+
+ return 0;
+}
+
+arch_initcall(bcm1480ht_pcibios_init);