From e47d488935ed0b2dd3d59d3ba4e13956ff6849c0 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Wed, 30 Mar 2011 09:27:49 +0200 Subject: MIPS: Lantiq: Add PCI controller support. The Lantiq family of SoCs have a EBU (External Bus Unit). This patch adds the driver that allows us to use the EBU as a PCI controller. In order for PCI to work the EBU is set to endianess swap all the data. In addition we need to make use of SWAP_IO_SPACE for device->host DMA to work. The clock of the PCI works in several modes (internal/external). If this is not configured correctly the SoC will hang. Signed-off-by: John Crispin Signed-off-by: Ralph Hempel Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2250/ Signed-off-by: Ralf Baechle --- arch/mips/pci/ops-lantiq.c | 116 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 arch/mips/pci/ops-lantiq.c (limited to 'arch/mips/pci/ops-lantiq.c') diff --git a/arch/mips/pci/ops-lantiq.c b/arch/mips/pci/ops-lantiq.c new file mode 100644 index 000000000000..1f2afb55cc71 --- /dev/null +++ b/arch/mips/pci/ops-lantiq.c @@ -0,0 +1,116 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * Copyright (C) 2010 John Crispin + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "pci-lantiq.h" + +#define LTQ_PCI_CFG_BUSNUM_SHF 16 +#define LTQ_PCI_CFG_DEVNUM_SHF 11 +#define LTQ_PCI_CFG_FUNNUM_SHF 8 + +#define PCI_ACCESS_READ 0 +#define PCI_ACCESS_WRITE 1 + +static int ltq_pci_config_access(unsigned char access_type, struct pci_bus *bus, + unsigned int devfn, unsigned int where, u32 *data) +{ + unsigned long cfg_base; + unsigned long flags; + u32 temp; + + /* we support slot from 0 to 15 dev_fn & 0x68 (AD29) is the + SoC itself */ + if ((bus->number != 0) || ((devfn & 0xf8) > 0x78) + || ((devfn & 0xf8) == 0) || ((devfn & 0xf8) == 0x68)) + return 1; + + spin_lock_irqsave(&ebu_lock, flags); + + cfg_base = (unsigned long) ltq_pci_mapped_cfg; + cfg_base |= (bus->number << LTQ_PCI_CFG_BUSNUM_SHF) | (devfn << + LTQ_PCI_CFG_FUNNUM_SHF) | (where & ~0x3); + + /* Perform access */ + if (access_type == PCI_ACCESS_WRITE) { + ltq_w32(swab32(*data), ((u32 *)cfg_base)); + } else { + *data = ltq_r32(((u32 *)(cfg_base))); + *data = swab32(*data); + } + wmb(); + + /* clean possible Master abort */ + cfg_base = (unsigned long) ltq_pci_mapped_cfg; + cfg_base |= (0x0 << LTQ_PCI_CFG_FUNNUM_SHF) + 4; + temp = ltq_r32(((u32 *)(cfg_base))); + temp = swab32(temp); + cfg_base = (unsigned long) ltq_pci_mapped_cfg; + cfg_base |= (0x68 << LTQ_PCI_CFG_FUNNUM_SHF) + 4; + ltq_w32(temp, ((u32 *)cfg_base)); + + spin_unlock_irqrestore(&ebu_lock, flags); + + if (((*data) == 0xffffffff) && (access_type == PCI_ACCESS_READ)) + return 1; + + return 0; +} + +int ltq_pci_read_config_dword(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + u32 data = 0; + + if (ltq_pci_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (size == 1) + *val = (data >> ((where & 3) << 3)) & 0xff; + else if (size == 2) + *val = (data >> ((where & 3) << 3)) & 0xffff; + else + *val = data; + + return PCIBIOS_SUCCESSFUL; +} + +int ltq_pci_write_config_dword(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + u32 data = 0; + + if (size == 4) { + data = val; + } else { + if (ltq_pci_config_access(PCI_ACCESS_READ, bus, + devfn, where, &data)) + return PCIBIOS_DEVICE_NOT_FOUND; + + if (size == 1) + data = (data & ~(0xff << ((where & 3) << 3))) | + (val << ((where & 3) << 3)); + else if (size == 2) + data = (data & ~(0xffff << ((where & 3) << 3))) | + (val << ((where & 3) << 3)); + } + + if (ltq_pci_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data)) + return PCIBIOS_DEVICE_NOT_FOUND; + + return PCIBIOS_SUCCESSFUL; +} -- cgit v1.2.3-59-g8ed1b