arch/sh/drivers/pci/ops-sh7786.c

   1 /*
   2  * Generic SH7786 PCI-Express operations.
   3  *
   4  *  Copyright (C) 2009  Paul Mundt
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License v2. See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/pci.h>
  13 #include <linux/io.h>
  14 #include <linux/spinlock.h>
  15 #include "pcie-sh7786.h"
  16
  17 enum {
  18         PCI_ACCESS_READ,
  19         PCI_ACCESS_WRITE,
  20 };
  21
  22 static DEFINE_SPINLOCK(sh7786_pcie_lock);
  23
  24 static int sh7786_pcie_config_access(unsigned char access_type,
  25                 struct pci_bus *bus, unsigned int devfn, int where, u32 *data)
  26 {
  27         struct pci_channel *chan = bus->sysdata;
  28         int dev, func;
  29
  30         dev = PCI_SLOT(devfn);
  31         func = PCI_FUNC(devfn);
  32
  33         if (bus->number > 255 || dev > 31 || func > 7)
  34                 return PCIBIOS_FUNC_NOT_SUPPORTED;
  35         if (devfn)
  36                 return PCIBIOS_DEVICE_NOT_FOUND;
  37
  38         /* Set the PIO address */
  39         pci_write_reg(chan, (bus->number << 24) | (dev << 19) |
  40                                 (func << 16) | (where & ~3), SH4A_PCIEPAR);
  41
  42         /* Enable the configuration access */
  43         pci_write_reg(chan, (1 << 31), SH4A_PCIEPCTLR);
  44
  45         if (access_type == PCI_ACCESS_READ)
  46                 *data = pci_read_reg(chan, SH4A_PCIEPDR);
  47         else
  48                 pci_write_reg(chan, *data, SH4A_PCIEPDR);
  49
  50         /* Check for master and target aborts */
  51         if (pci_read_reg(chan, SH4A_PCIEPCICONF1) & ((1 << 29) | (1 << 28)))
  52                 return PCIBIOS_DEVICE_NOT_FOUND;
  53
  54         return PCIBIOS_SUCCESSFUL;
  55 }
  56
  57 static int sh7786_pcie_read(struct pci_bus *bus, unsigned int devfn,
  58                             int where, int size, u32 *val)
  59 {
  60         unsigned long flags;
  61         int ret;
  62         u32 data;
  63
  64         if ((size == 2) && (where & 1))
  65                 return PCIBIOS_BAD_REGISTER_NUMBER;
  66         else if ((size == 4) && (where & 3))
  67                 return PCIBIOS_BAD_REGISTER_NUMBER;
  68
  69         spin_lock_irqsave(&sh7786_pcie_lock, flags);
  70         ret = sh7786_pcie_config_access(PCI_ACCESS_READ, bus,
  71                                         devfn, where, &data);
  72         if (ret != PCIBIOS_SUCCESSFUL)
  73                 goto out;
  74
  75         if (size == 1)
  76                 *val = (data >> ((where & 3) << 3)) & 0xff;
  77         else if (size == 2)
  78                 *val = (data >> ((where & 2) << 3)) & 0xffff;
  79         else
  80                 *val = data;
  81
  82         dev_dbg(&bus->dev, "pcie-config-read: bus=%3d devfn=0x%04x "
  83                 "where=0x%04x size=%d val=0x%08lx\n", bus->number,
  84                 devfn, where, size, (unsigned long)*val);
  85
  86 out:
  87         spin_unlock_irqrestore(&sh7786_pcie_lock, flags);
  88         return ret;
  89 }
  90
  91 static int sh7786_pcie_write(struct pci_bus *bus, unsigned int devfn,
  92                              int where, int size, u32 val)
  93 {
  94         unsigned long flags;
  95         int shift, ret;
  96         u32 data;
  97
  98         if ((size == 2) && (where & 1))
  99                 return PCIBIOS_BAD_REGISTER_NUMBER;
 100         else if ((size == 4) && (where & 3))
 101                 return PCIBIOS_BAD_REGISTER_NUMBER;
 102
 103         spin_lock_irqsave(&sh7786_pcie_lock, flags);
 104         ret = sh7786_pcie_config_access(PCI_ACCESS_READ, bus,
 105                                         devfn, where, &data);
 106         if (ret != PCIBIOS_SUCCESSFUL)
 107                 goto out;
 108
 109         dev_dbg(&bus->dev, "pcie-config-write: bus=%3d devfn=0x%04x "
 110                 "where=0x%04x size=%d val=%08lx\n", bus->number,
 111                 devfn, where, size, (unsigned long)val);
 112
 113         if (size == 1) {
 114                 shift = (where & 3) << 3;
 115                 data &= ~(0xff << shift);
 116                 data |= ((val & 0xff) << shift);
 117         } else if (size == 2) {
 118                 shift = (where & 2) << 3;
 119                 data &= ~(0xffff << shift);
 120                 data |= ((val & 0xffff) << shift);
 121         } else
 122                 data = val;
 123
 124         ret = sh7786_pcie_config_access(PCI_ACCESS_WRITE, bus,
 125                                         devfn, where, &data);
 126 out:
 127         spin_unlock_irqrestore(&sh7786_pcie_lock, flags);
 128         return ret;
 129 }
 130
 131 struct pci_ops sh7786_pci_ops = {
 132         .read   = sh7786_pcie_read,
 133         .write  = sh7786_pcie_write,
 134 };