diff options
Diffstat (limited to 'arch/mips/pci/ops-msc.c')
-rw-r--r-- | arch/mips/pci/ops-msc.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/mips/pci/ops-msc.c b/arch/mips/pci/ops-msc.c new file mode 100644 index 000000000..1f438baaf --- /dev/null +++ b/arch/mips/pci/ops-msc.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 1999, 2000, 2004, 2005 MIPS Technologies, Inc. + * All rights reserved. + * Authors: Carsten Langgaard <carstenl@mips.com> + * Maciej W. Rozycki <macro@mips.com> + * Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org) + * + * MIPS boards specific PCI support. + */ +#include <linux/types.h> +#include <linux/pci.h> +#include <linux/kernel.h> + +#include <asm/mips-boards/msc01_pci.h> + +#define PCI_ACCESS_READ 0 +#define PCI_ACCESS_WRITE 1 + +/* + * PCI configuration cycle AD bus definition + */ +/* Type 0 */ +#define PCI_CFG_TYPE0_REG_SHF 0 +#define PCI_CFG_TYPE0_FUNC_SHF 8 + +/* Type 1 */ +#define PCI_CFG_TYPE1_REG_SHF 0 +#define PCI_CFG_TYPE1_FUNC_SHF 8 +#define PCI_CFG_TYPE1_DEV_SHF 11 +#define PCI_CFG_TYPE1_BUS_SHF 16 + +static int msc_pcibios_config_access(unsigned char access_type, + struct pci_bus *bus, unsigned int devfn, int where, u32 * data) +{ + unsigned char busnum = bus->number; + u32 intr; + + /* Clear status register bits. */ + MSC_WRITE(MSC01_PCI_INTSTAT, + (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT)); + + MSC_WRITE(MSC01_PCI_CFGADDR, + ((busnum << MSC01_PCI_CFGADDR_BNUM_SHF) | + (PCI_SLOT(devfn) << MSC01_PCI_CFGADDR_DNUM_SHF) | + (PCI_FUNC(devfn) << MSC01_PCI_CFGADDR_FNUM_SHF) | + ((where / 4) << MSC01_PCI_CFGADDR_RNUM_SHF))); + + /* Perform access */ + if (access_type == PCI_ACCESS_WRITE) + MSC_WRITE(MSC01_PCI_CFGDATA, *data); + else + MSC_READ(MSC01_PCI_CFGDATA, *data); + + /* Detect Master/Target abort */ + MSC_READ(MSC01_PCI_INTSTAT, intr); + if (intr & (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT)) { + /* Error occurred */ + + /* Clear bits */ + MSC_WRITE(MSC01_PCI_INTSTAT, + (MSC01_PCI_INTCFG_MA_BIT | MSC01_PCI_INTCFG_TA_BIT)); + + return -1; + } + + return 0; +} + + +/* + * We can't address 8 and 16 bit words directly. Instead we have to + * read/write a 32bit word and mask/modify the data we actually want. + */ +static int msc_pcibios_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 * val) +{ + u32 data = 0; + + if ((size == 2) && (where & 1)) + return PCIBIOS_BAD_REGISTER_NUMBER; + else if ((size == 4) && (where & 3)) + return PCIBIOS_BAD_REGISTER_NUMBER; + + if (msc_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, + &data)) + return -1; + + 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; +} + +static int msc_pcibios_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + u32 data = 0; + + if ((size == 2) && (where & 1)) + return PCIBIOS_BAD_REGISTER_NUMBER; + else if ((size == 4) && (where & 3)) + return PCIBIOS_BAD_REGISTER_NUMBER; + + if (size == 4) + data = val; + else { + if (msc_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, + where, &data)) + return -1; + + 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 (msc_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where, + &data)) + return -1; + + return PCIBIOS_SUCCESSFUL; +} + +struct pci_ops msc_pci_ops = { + .read = msc_pcibios_read, + .write = msc_pcibios_write +}; |