arch/arm/mach-sa1100/pci-nanoengine.c

   1 /*
   2  * linux/arch/arm/mach-sa1100/pci-nanoengine.c
   3  *
   4  * PCI functions for BSE nanoEngine PCI
   5  *
   6  * Copyright (C) 2010 Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22 #include <linux/kernel.h>
  23 #include <linux/irq.h>
  24 #include <linux/pci.h>
  25 #include <linux/spinlock.h>
  26
  27 #include <asm/mach/pci.h>
  28 #include <asm/mach-types.h>
  29
  30 #include <mach/nanoengine.h>
  31 #include <mach/hardware.h>
  32
  33 static DEFINE_SPINLOCK(nano_lock);
  34
  35 static int nanoengine_get_pci_address(struct pci_bus *bus,
  36         unsigned int devfn, int where, unsigned long *address)
  37 {
  38         int ret = PCIBIOS_DEVICE_NOT_FOUND;
  39         unsigned int busnr = bus->number;
  40
  41         *address = NANO_PCI_CONFIG_SPACE_VIRT +
  42                 ((bus->number << 16) | (devfn << 8) | (where & ~3));
  43
  44         ret = (busnr > 255 || devfn > 255 || where > 255) ?
  45                 PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
  46
  47         return ret;
  48 }
  49
  50 static int nanoengine_read_config(struct pci_bus *bus, unsigned int devfn, int where,
  51         int size, u32 *val)
  52 {
  53         int ret;
  54         unsigned long address;
  55         unsigned long flags;
  56         u32 v;
  57
  58         /* nanoEngine PCI bridge does not return -1 for a non-existing
  59          * device. We must fake the answer. We know that the only valid
  60          * device is device zero at bus 0, which is the network chip. */
  61         if (bus->number != 0 || (devfn >> 3) != 0) {
  62                 v = -1;
  63                 nanoengine_get_pci_address(bus, devfn, where, &address);
  64                 goto exit_function;
  65         }
  66
  67         spin_lock_irqsave(&nano_lock, flags);
  68
  69         ret = nanoengine_get_pci_address(bus, devfn, where, &address);
  70         if (ret != PCIBIOS_SUCCESSFUL)
  71                 return ret;
  72         v = __raw_readl(address);
  73
  74         spin_unlock_irqrestore(&nano_lock, flags);
  75
  76         v >>= ((where & 3) * 8);
  77         v &= (unsigned long)(-1) >> ((4 - size) * 8);
  78
  79 exit_function:
  80         *val = v;
  81         return PCIBIOS_SUCCESSFUL;
  82 }
  83
  84 static int nanoengine_write_config(struct pci_bus *bus, unsigned int devfn, int where,
  85         int size, u32 val)
  86 {
  87         int ret;
  88         unsigned long address;
  89         unsigned long flags;
  90         unsigned shift;
  91         u32 v;
  92
  93         shift = (where & 3) * 8;
  94
  95         spin_lock_irqsave(&nano_lock, flags);
  96
  97         ret = nanoengine_get_pci_address(bus, devfn, where, &address);
  98         if (ret != PCIBIOS_SUCCESSFUL)
  99                 return ret;
 100         v = __raw_readl(address);
 101         switch (size) {
 102         case 1:
 103                 v &= ~(0xFF << shift);
 104                 v |= val << shift;
 105                 break;
 106         case 2:
 107                 v &= ~(0xFFFF << shift);
 108                 v |= val << shift;
 109                 break;
 110         case 4:
 111                 v = val;
 112                 break;
 113         }
 114         __raw_writel(v, address);
 115
 116         spin_unlock_irqrestore(&nano_lock, flags);
 117
 118         return PCIBIOS_SUCCESSFUL;
 119 }
 120
 121 static struct pci_ops pci_nano_ops = {
 122         .read   = nanoengine_read_config,
 123         .write  = nanoengine_write_config,
 124 };
 125
 126 static int __init pci_nanoengine_map_irq(const struct pci_dev *dev, u8 slot,
 127         u8 pin)
 128 {
 129         return NANOENGINE_IRQ_GPIO_PCI;
 130 }
 131
 132 struct pci_bus * __init pci_nanoengine_scan_bus(int nr, struct pci_sys_data *sys)
 133 {
 134         return pci_scan_bus(sys->busnr, &pci_nano_ops, sys);
 135 }
 136
 137 static struct resource pci_io_ports = {
 138         .name   = "PCI IO",
 139         .start  = 0x400,
 140         .end    = 0x7FF,
 141         .flags  = IORESOURCE_IO,
 142 };
 143
 144 static struct resource pci_non_prefetchable_memory = {
 145         .name   = "PCI non-prefetchable",
 146         .start  = NANO_PCI_MEM_RW_PHYS,
 147         /* nanoEngine documentation says there is a 1 Megabyte window here,
 148          * but PCI reports just 128 + 8 kbytes. */
 149         .end    = NANO_PCI_MEM_RW_PHYS + NANO_PCI_MEM_RW_SIZE - 1,
 150 /*      .end    = NANO_PCI_MEM_RW_PHYS + SZ_128K + SZ_8K - 1,*/
 151         .flags  = IORESOURCE_MEM,
 152 };
 153
 154 /*
 155  * nanoEngine PCI reports 1 Megabyte of prefetchable memory, but it
 156  * overlaps with previously defined memory.
 157  *
 158  * Here is what happens:
 159  *
 160 # dmesg
 161 ...
 162 pci 0000:00:00.0: [8086:1209] type 0 class 0x000200
 163 pci 0000:00:00.0: reg 10: [mem 0x00021000-0x00021fff]
 164 pci 0000:00:00.0: reg 14: [io  0x0000-0x003f]
 165 pci 0000:00:00.0: reg 18: [mem 0x00000000-0x0001ffff]
 166 pci 0000:00:00.0: reg 30: [mem 0x00000000-0x000fffff pref]
 167 pci 0000:00:00.0: supports D1 D2
 168 pci 0000:00:00.0: PME# supported from D0 D1 D2 D3hot
 169 pci 0000:00:00.0: PME# disabled
 170 PCI: bus0: Fast back to back transfers enabled
 171 pci 0000:00:00.0: BAR 6: can't assign mem pref (size 0x100000)
 172 pci 0000:00:00.0: BAR 2: assigned [mem 0x18600000-0x1861ffff]
 173 pci 0000:00:00.0: BAR 2: set to [mem 0x18600000-0x1861ffff] (PCI address [0x0-0x1ffff])
 174 pci 0000:00:00.0: BAR 0: assigned [mem 0x18620000-0x18620fff]
 175 pci 0000:00:00.0: BAR 0: set to [mem 0x18620000-0x18620fff] (PCI address [0x20000-0x20fff])
 176 pci 0000:00:00.0: BAR 1: assigned [io  0x0400-0x043f]
 177 pci 0000:00:00.0: BAR 1: set to [io  0x0400-0x043f] (PCI address [0x0-0x3f])
 178  *
 179  * On the other hand, if we do not request the prefetchable memory resource,
 180  * linux will alloc it first and the two non-prefetchable memory areas that
 181  * are our real interest will not be mapped. So we choose to map it to an
 182  * unused area. It gets recognized as expansion ROM, but becomes disabled.
 183  *
 184  * Here is what happens then:
 185  *
 186 # dmesg
 187 ...
 188 pci 0000:00:00.0: [8086:1209] type 0 class 0x000200
 189 pci 0000:00:00.0: reg 10: [mem 0x00021000-0x00021fff]
 190 pci 0000:00:00.0: reg 14: [io  0x0000-0x003f]
 191 pci 0000:00:00.0: reg 18: [mem 0x00000000-0x0001ffff]
 192 pci 0000:00:00.0: reg 30: [mem 0x00000000-0x000fffff pref]
 193 pci 0000:00:00.0: supports D1 D2
 194 pci 0000:00:00.0: PME# supported from D0 D1 D2 D3hot
 195 pci 0000:00:00.0: PME# disabled
 196 PCI: bus0: Fast back to back transfers enabled
 197 pci 0000:00:00.0: BAR 6: assigned [mem 0x78000000-0x780fffff pref]
 198 pci 0000:00:00.0: BAR 2: assigned [mem 0x18600000-0x1861ffff]
 199 pci 0000:00:00.0: BAR 2: set to [mem 0x18600000-0x1861ffff] (PCI address [0x0-0x1ffff])
 200 pci 0000:00:00.0: BAR 0: assigned [mem 0x18620000-0x18620fff]
 201 pci 0000:00:00.0: BAR 0: set to [mem 0x18620000-0x18620fff] (PCI address [0x20000-0x20fff])
 202 pci 0000:00:00.0: BAR 1: assigned [io  0x0400-0x043f]
 203 pci 0000:00:00.0: BAR 1: set to [io  0x0400-0x043f] (PCI address [0x0-0x3f])
 204
 205 # lspci -vv -s 0000:00:00.0
 206 00:00.0 Class 0200: Device 8086:1209 (rev 09)
 207         Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx-
 208         Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR+ <PERR+ INTx-
 209         Latency: 0 (2000ns min, 14000ns max), Cache Line Size: 32 bytes
 210         Interrupt: pin A routed to IRQ 0
 211         Region 0: Memory at 18620000 (32-bit, non-prefetchable) [size=4K]
 212         Region 1: I/O ports at 0400 [size=64]
 213         Region 2: [virtual] Memory at 18600000 (32-bit, non-prefetchable) [size=128K]
 214         [virtual] Expansion ROM at 78000000 [disabled] [size=1M]
 215         Capabilities: [dc] Power Management version 2
 216                 Flags: PMEClk- DSI+ D1+ D2+ AuxCurrent=0mA PME(D0+,D1+,D2+,D3hot+,D3cold-)
 217                 Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=2 PME-
 218         Kernel driver in use: e100
 219         Kernel modules: e100
 220  *
 221  */
 222 static struct resource pci_prefetchable_memory = {
 223         .name   = "PCI prefetchable",
 224         .start  = 0x78000000,
 225         .end    = 0x78000000 + NANO_PCI_MEM_RW_SIZE - 1,
 226         .flags  = IORESOURCE_MEM  | IORESOURCE_PREFETCH,
 227 };
 228
 229 static int __init pci_nanoengine_setup_resources(struct resource **resource)
 230 {
 231         if (request_resource(&ioport_resource, &pci_io_ports)) {
 232                 printk(KERN_ERR "PCI: unable to allocate io port region\n");
 233                 return -EBUSY;
 234         }
 235         if (request_resource(&iomem_resource, &pci_non_prefetchable_memory)) {
 236                 release_resource(&pci_io_ports);
 237                 printk(KERN_ERR "PCI: unable to allocate non prefetchable\n");
 238                 return -EBUSY;
 239         }
 240         if (request_resource(&iomem_resource, &pci_prefetchable_memory)) {
 241                 release_resource(&pci_io_ports);
 242                 release_resource(&pci_non_prefetchable_memory);
 243                 printk(KERN_ERR "PCI: unable to allocate prefetchable\n");
 244                 return -EBUSY;
 245         }
 246         resource[0] = &pci_io_ports;
 247         resource[1] = &pci_non_prefetchable_memory;
 248         resource[2] = &pci_prefetchable_memory;
 249
 250         return 1;
 251 }
 252
 253 int __init pci_nanoengine_setup(int nr, struct pci_sys_data *sys)
 254 {
 255         int ret = 0;
 256
 257         pcibios_min_io = 0;
 258         pcibios_min_mem = 0;
 259
 260         if (nr == 0) {
 261                 sys->mem_offset = NANO_PCI_MEM_RW_PHYS;
 262                 sys->io_offset = 0x400;
 263                 ret = pci_nanoengine_setup_resources(sys->resource);
 264                 /* Enable alternate memory bus master mode, see
 265                  * "Intel StrongARM SA1110 Developer's Manual",
 266                  * section 10.8, "Alternate Memory Bus Master Mode". */
 267                 GPDR = (GPDR & ~GPIO_MBREQ) | GPIO_MBGNT;
 268                 GAFR |= GPIO_MBGNT | GPIO_MBREQ;
 269                 TUCR |= TUCR_MBGPIO;
 270         }
 271
 272         return ret;
 273 }
 274
 275 static struct hw_pci nanoengine_pci __initdata = {
 276         .map_irq                = pci_nanoengine_map_irq,
 277         .nr_controllers         = 1,
 278         .scan                   = pci_nanoengine_scan_bus,
 279         .setup                  = pci_nanoengine_setup,
 280 };
 281
 282 static int __init nanoengine_pci_init(void)
 283 {
 284         if (machine_is_nanoengine())
 285                 pci_common_init(&nanoengine_pci);
 286         return 0;
 287 }
 288
 289 subsys_initcall(nanoengine_pci_init);