--- /dev/null
+/*
+ * Generic SH7786 PCI-Express operations.
+ *
+ * Copyright (C) 2009 - 2010 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License v2. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include "pcie-sh7786.h"
+
+enum {
+ PCI_ACCESS_READ,
+ PCI_ACCESS_WRITE,
+};
+
+static int sh7786_pcie_config_access(unsigned char access_type,
+ struct pci_bus *bus, unsigned int devfn, int where, u32 *data)
+{
+ struct pci_channel *chan = bus->sysdata;
+ int dev, func, type, reg;
+
+ dev = PCI_SLOT(devfn);
+ func = PCI_FUNC(devfn);
+ type = !!bus->parent;
+ reg = where & ~3;
+
+ if (bus->number > 255 || dev > 31 || func > 7)
+ return PCIBIOS_FUNC_NOT_SUPPORTED;
+
+ /*
+ * While each channel has its own memory-mapped extended config
+ * space, it's generally only accessible when in endpoint mode.
+ * When in root complex mode, the controller is unable to target
+ * itself with either type 0 or type 1 accesses, and indeed, any
+ * controller initiated target transfer to its own config space
+ * result in a completer abort.
+ *
+ * Each channel effectively only supports a single device, but as
+ * the same channel <-> device access works for any PCI_SLOT()
+ * value, we cheat a bit here and bind the controller's config
+ * space to devfn 0 in order to enable self-enumeration. In this
+ * case the regular PAR/PDR path is sidelined and the mangled
+ * config access itself is initiated as a SuperHyway transaction.
+ */
+ if (pci_is_root_bus(bus)) {
+ if (dev == 0) {
+ if (access_type == PCI_ACCESS_READ)
+ *data = pci_read_reg(chan, PCI_REG(reg));
+ else
+ pci_write_reg(chan, *data, PCI_REG(reg));
+
+ return PCIBIOS_SUCCESSFUL;
+ } else if (dev > 1)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ /* Clear errors */
+ pci_write_reg(chan, pci_read_reg(chan, SH4A_PCIEERRFR), SH4A_PCIEERRFR);
+
+ /* Set the PIO address */
+ pci_write_reg(chan, (bus->number << 24) | (dev << 19) |
+ (func << 16) | reg, SH4A_PCIEPAR);
+
+ /* Enable the configuration access */
+ pci_write_reg(chan, (1 << 31) | (type << 8), SH4A_PCIEPCTLR);
+
+ /* Check for errors */
+ if (pci_read_reg(chan, SH4A_PCIEERRFR) & 0x10)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /* Check for master and target aborts */
+ if (pci_read_reg(chan, SH4A_PCIEPCICONF1) & ((1 << 29) | (1 << 28)))
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (access_type == PCI_ACCESS_READ)
+ *data = pci_read_reg(chan, SH4A_PCIEPDR);
+ else
+ pci_write_reg(chan, *data, SH4A_PCIEPDR);
+
+ /* Disable the configuration access */
+ pci_write_reg(chan, 0, SH4A_PCIEPCTLR);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+static int sh7786_pcie_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ unsigned long flags;
+ int ret;
+ u32 data;
+
+ if ((size == 2) && (where & 1))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ else if ((size == 4) && (where & 3))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ raw_spin_lock_irqsave(&pci_config_lock, flags);
+ ret = sh7786_pcie_config_access(PCI_ACCESS_READ, bus,
+ devfn, where, &data);
+ if (ret != PCIBIOS_SUCCESSFUL) {
+ *val = 0xffffffff;
+ goto out;
+ }
+
+ if (size == 1)
+ *val = (data >> ((where & 3) << 3)) & 0xff;
+ else if (size == 2)
+ *val = (data >> ((where & 2) << 3)) & 0xffff;
+ else
+ *val = data;
+
+ dev_dbg(&bus->dev, "pcie-config-read: bus=%3d devfn=0x%04x "
+ "where=0x%04x size=%d val=0x%08lx\n", bus->number,
+ devfn, where, size, (unsigned long)*val);
+
+out:
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+ return ret;
+}
+
+static int sh7786_pcie_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ unsigned long flags;
+ int shift, ret;
+ u32 data;
+
+ if ((size == 2) && (where & 1))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+ else if ((size == 4) && (where & 3))
+ return PCIBIOS_BAD_REGISTER_NUMBER;
+
+ raw_spin_lock_irqsave(&pci_config_lock, flags);
+ ret = sh7786_pcie_config_access(PCI_ACCESS_READ, bus,
+ devfn, where, &data);
+ if (ret != PCIBIOS_SUCCESSFUL)
+ goto out;
+
+ dev_dbg(&bus->dev, "pcie-config-write: bus=%3d devfn=0x%04x "
+ "where=0x%04x size=%d val=%08lx\n", bus->number,
+ devfn, where, size, (unsigned long)val);
+
+ if (size == 1) {
+ shift = (where & 3) << 3;
+ data &= ~(0xff << shift);
+ data |= ((val & 0xff) << shift);
+ } else if (size == 2) {
+ shift = (where & 2) << 3;
+ data &= ~(0xffff << shift);
+ data |= ((val & 0xffff) << shift);
+ } else
+ data = val;
+
+ ret = sh7786_pcie_config_access(PCI_ACCESS_WRITE, bus,
+ devfn, where, &data);
+out:
+ raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+ return ret;
+}
+
+struct pci_ops sh7786_pci_ops = {
+ .read = sh7786_pcie_read,
+ .write = sh7786_pcie_write,
+};
Code Review / kvmfornfv.git / blobdiff