ARM: 6459/2: sa1100: Add nanoEngine PCI support.

This patch adds nanoEngine's PCI support.

Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 284 insertions, 0 deletions

diff --git a/arch/arm/mach-sa1100/pci-nanoengine.c b/arch/arm/mach-sa1100/pci-nanoengine.c
new file mode 100644
index 000000000000..fba7a913f12b
--- /dev/null
+++ b/arch/arm/mach-sa1100/pci-nanoengine.c
@@ -0,0 +1,284 @@
+/*
+ * linux/arch/arm/mach-sa1100/pci-nanoengine.c
+ *
+ * PCI functions for BSE nanoEngine PCI
+ *
+ * Copyright (C) 2010 Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+
+#include <asm/mach/pci.h>
+#include <asm/mach-types.h>
+
+#include <mach/nanoengine.h>
+
+static DEFINE_SPINLOCK(nano_lock);
+
+static int nanoengine_get_pci_address(struct pci_bus *bus,
+        unsigned int devfn, int where, unsigned long *address)
+{
+        int ret = PCIBIOS_DEVICE_NOT_FOUND;
+        unsigned int busnr = bus->number;
+
+        *address = NANO_PCI_CONFIG_SPACE_VIRT +
+                ((bus->number << 16) | (devfn << 8) | (where & ~3));
+
+        ret = (busnr > 255 || devfn > 255 || where > 255) ?
+                PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+        return ret;
+}
+
+static int nanoengine_read_config(struct pci_bus *bus, unsigned int devfn, int where,
+        int size, u32 *val)
+{
+        int ret;
+        unsigned long address;
+        unsigned long flags;
+        u32 v;
+
+        /* nanoEngine PCI bridge does not return -1 for a non-existing
+         * device. We must fake the answer. We know that the only valid
+         * device is device zero at bus 0, which is the network chip. */
+        if (bus->number != 0 || (devfn >> 3) != 0) {
+                v = -1;
+                nanoengine_get_pci_address(bus, devfn, where, &address);
+                goto exit_function;
+        }
+
+        spin_lock_irqsave(&nano_lock, flags);
+
+        ret = nanoengine_get_pci_address(bus, devfn, where, &address);
+        if (ret != PCIBIOS_SUCCESSFUL)
+                return ret;
+        v = __raw_readl(address);
+
+        spin_unlock_irqrestore(&nano_lock, flags);
+
+        v >>= ((where & 3) * 8);
+        v &= (unsigned long)(-1) >> ((4 - size) * 8);
+
+exit_function:
+        *val = v;
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static int nanoengine_write_config(struct pci_bus *bus, unsigned int devfn, int where,
+        int size, u32 val)
+{
+        int ret;
+        unsigned long address;
+        unsigned long flags;
+        unsigned shift;
+        u32 v;
+
+        shift = (where & 3) * 8;
+
+        spin_lock_irqsave(&nano_lock, flags);
+
+        ret = nanoengine_get_pci_address(bus, devfn, where, &address);
+        if (ret != PCIBIOS_SUCCESSFUL)
+                return ret;
+        v = __raw_readl(address);
+        switch (size) {
+        case 1:
+                v &= ~(0xFF << shift);
+                v |= val << shift;
+                break;
+        case 2:
+                v &= ~(0xFFFF << shift);
+                v |= val << shift;
+                break;
+        case 4:
+                v = val;
+                break;
+        }
+        __raw_writel(v, address);
+
+        spin_unlock_irqrestore(&nano_lock, flags);
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops pci_nano_ops = {
+        .read   = nanoengine_read_config,
+        .write  = nanoengine_write_config,
+};
+
+static int __init pci_nanoengine_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
+{
+        return NANOENGINE_IRQ_GPIO_PCI;
+}
+
+struct pci_bus * __init pci_nanoengine_scan_bus(int nr, struct pci_sys_data *sys)
+{
+        return pci_scan_bus(sys->busnr, &pci_nano_ops, sys);
+}
+
+static struct resource pci_io_ports = {
+        .name   = "PCI IO",
+        .start  = 0x400,
+        .end    = 0x7FF,
+        .flags  = IORESOURCE_IO,
+};
+
+static struct resource pci_non_prefetchable_memory = {
+        .name   = "PCI non-prefetchable",
+        .start  = NANO_PCI_MEM_RW_PHYS,
+        /* nanoEngine documentation says there is a 1 Megabyte window here,
+         * but PCI reports just 128 + 8 kbytes. */
+        .end    = NANO_PCI_MEM_RW_PHYS + NANO_PCI_MEM_RW_SIZE - 1,
+/*      .end    = NANO_PCI_MEM_RW_PHYS + SZ_128K + SZ_8K - 1,*/
+        .flags  = IORESOURCE_MEM,
+};
+
+/*
+ * nanoEngine PCI reports 1 Megabyte of prefetchable memory, but it
+ * overlaps with previously defined memory.
+ *
+ * Here is what happens:
+ *
+# dmesg
+...
+pci 0000:00:00.0: [8086:1209] type 0 class 0x000200
+pci 0000:00:00.0: reg 10: [mem 0x00021000-0x00021fff]
+pci 0000:00:00.0: reg 14: [io  0x0000-0x003f]
+pci 0000:00:00.0: reg 18: [mem 0x00000000-0x0001ffff]
+pci 0000:00:00.0: reg 30: [mem 0x00000000-0x000fffff pref]
+pci 0000:00:00.0: supports D1 D2
+pci 0000:00:00.0: PME# supported from D0 D1 D2 D3hot
+pci 0000:00:00.0: PME# disabled
+PCI: bus0: Fast back to back transfers enabled
+pci 0000:00:00.0: BAR 6: can't assign mem pref (size 0x100000)
+pci 0000:00:00.0: BAR 2: assigned [mem 0x18600000-0x1861ffff]
+pci 0000:00:00.0: BAR 2: set to [mem 0x18600000-0x1861ffff] (PCI address [0x0-0x1ffff])
+pci 0000:00:00.0: BAR 0: assigned [mem 0x18620000-0x18620fff]
+pci 0000:00:00.0: BAR 0: set to [mem 0x18620000-0x18620fff] (PCI address [0x20000-0x20fff])
+pci 0000:00:00.0: BAR 1: assigned [io  0x0400-0x043f]
+pci 0000:00:00.0: BAR 1: set to [io  0x0400-0x043f] (PCI address [0x0-0x3f])
+ *
+ * On the other hand, if we do not request the prefetchable memory resource,
+ * linux will alloc it first and the two non-prefetchable memory areas that
+ * are our real interest will not be mapped. So we choose to map it to an
+ * unused area. It gets recognized as expansion ROM, but becomes disabled.
+ *
+ * Here is what happens then:
+ *
+# dmesg
+...
+pci 0000:00:00.0: [8086:1209] type 0 class 0x000200
+pci 0000:00:00.0: reg 10: [mem 0x00021000-0x00021fff]
+pci 0000:00:00.0: reg 14: [io  0x0000-0x003f]
+pci 0000:00:00.0: reg 18: [mem 0x00000000-0x0001ffff]
+pci 0000:00:00.0: reg 30: [mem 0x00000000-0x000fffff pref]
+pci 0000:00:00.0: supports D1 D2
+pci 0000:00:00.0: PME# supported from D0 D1 D2 D3hot
+pci 0000:00:00.0: PME# disabled
+PCI: bus0: Fast back to back transfers enabled
+pci 0000:00:00.0: BAR 6: assigned [mem 0x78000000-0x780fffff pref]
+pci 0000:00:00.0: BAR 2: assigned [mem 0x18600000-0x1861ffff]
+pci 0000:00:00.0: BAR 2: set to [mem 0x18600000-0x1861ffff] (PCI address [0x0-0x1ffff])
+pci 0000:00:00.0: BAR 0: assigned [mem 0x18620000-0x18620fff]
+pci 0000:00:00.0: BAR 0: set to [mem 0x18620000-0x18620fff] (PCI address [0x20000-0x20fff])
+pci 0000:00:00.0: BAR 1: assigned [io  0x0400-0x043f]
+pci 0000:00:00.0: BAR 1: set to [io  0x0400-0x043f] (PCI address [0x0-0x3f])
+
+# lspci -vv -s 0000:00:00.0
+00:00.0 Class 0200: Device 8086:1209 (rev 09)
+        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
+        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR+ <PERR+ INTx-
+        Latency: 0 (2000ns min, 14000ns max), Cache Line Size: 32 bytes
+        Interrupt: pin A routed to IRQ 0
+        Region 0: Memory at 18620000 (32-bit, non-prefetchable) [size=4K]
+        Region 1: I/O ports at 0400 [size=64]
+        Region 2: [virtual] Memory at 18600000 (32-bit, non-prefetchable) [size=128K]
+        [virtual] Expansion ROM at 78000000 [disabled] [size=1M]
+        Capabilities: [dc] Power Management version 2
+                Flags: PMEClk- DSI+ D1+ D2+ AuxCurrent=0mA PME(D0+,D1+,D2+,D3hot+,D3cold-)
+                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=2 PME-
+        Kernel driver in use: e100
+        Kernel modules: e100
+ *
+ */
+static struct resource pci_prefetchable_memory = {
+        .name   = "PCI prefetchable",
+        .start  = 0x78000000,
+        .end    = 0x78000000 + NANO_PCI_MEM_RW_SIZE - 1,
+        .flags  = IORESOURCE_MEM  | IORESOURCE_PREFETCH,
+};
+
+static int __init pci_nanoengine_setup_resources(struct resource **resource)
+{
+        if (request_resource(&ioport_resource, &pci_io_ports)) {
+                printk(KERN_ERR "PCI: unable to allocate io port region\n");
+                return -EBUSY;
+        }
+        if (request_resource(&iomem_resource, &pci_non_prefetchable_memory)) {
+                release_resource(&pci_io_ports);
+                printk(KERN_ERR "PCI: unable to allocate non prefetchable\n");
+                return -EBUSY;
+        }
+        if (request_resource(&iomem_resource, &pci_prefetchable_memory)) {
+                release_resource(&pci_io_ports);
+                release_resource(&pci_non_prefetchable_memory);
+                printk(KERN_ERR "PCI: unable to allocate prefetchable\n");
+                return -EBUSY;
+        }
+        resource[0] = &pci_io_ports;
+        resource[1] = &pci_non_prefetchable_memory;
+        resource[2] = &pci_prefetchable_memory;
+
+        return 1;
+}
+
+int __init pci_nanoengine_setup(int nr, struct pci_sys_data *sys)
+{
+        int ret = 0;
+
+        if (nr == 0) {
+                sys->mem_offset = NANO_PCI_MEM_RW_PHYS;
+                sys->io_offset = 0x400;
+                ret = pci_nanoengine_setup_resources(sys->resource);
+                /* Enable alternate memory bus master mode, see
+                 * "Intel StrongARM SA1110 Developer's Manual",
+                 * section 10.8, "Alternate Memory Bus Master Mode". */
+                GPDR = (GPDR & ~GPIO_MBREQ) | GPIO_MBGNT;
+                GAFR |= GPIO_MBGNT | GPIO_MBREQ;
+                TUCR |= TUCR_MBGPIO;
+        }
+
+        return ret;
+}
+
+static struct hw_pci nanoengine_pci __initdata = {
+        .map_irq                = pci_nanoengine_map_irq,
+        .nr_controllers         = 1,
+        .scan                   = pci_nanoengine_scan_bus,
+        .setup                  = pci_nanoengine_setup,
+};
+
+static int __init nanoengine_pci_init(void)
+{
+        if (machine_is_nanoengine())
+                pci_common_init(&nanoengine_pci);
+        return 0;
+}
+
+subsys_initcall(nanoengine_pci_init);