diff options
Diffstat (limited to 'arch/sh/drivers/pci/ops-sh7786.c')
| -rw-r--r-- | arch/sh/drivers/pci/ops-sh7786.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/ops-sh7786.c b/arch/sh/drivers/pci/ops-sh7786.c new file mode 100644 index 0000000000..a10f9f4ebd --- /dev/null +++ b/arch/sh/drivers/pci/ops-sh7786.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic SH7786 PCI-Express operations. + * + * Copyright (C) 2009 - 2010 Paul Mundt + */ +#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, +}; |