diff options
Diffstat (limited to 'arch/sh/drivers/pci/ops-sh4.c')
-rw-r--r-- | arch/sh/drivers/pci/ops-sh4.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/ops-sh4.c b/arch/sh/drivers/pci/ops-sh4.c new file mode 100644 index 0000000000..a205be3bfc --- /dev/null +++ b/arch/sh/drivers/pci/ops-sh4.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic SH-4 / SH-4A PCIC operations (SH7751, SH7780). + * + * Copyright (C) 2002 - 2009 Paul Mundt + */ +#include <linux/pci.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <asm/addrspace.h> +#include "pci-sh4.h" + +/* + * Direct access to PCI hardware... + */ +#define CONFIG_CMD(bus, devfn, where) \ + (0x80000000 | (bus->number << 16) | (devfn << 8) | (where & ~3)) + +/* + * Functions for accessing PCI configuration space with type 1 accesses + */ +static int sh4_pci_read(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct pci_channel *chan = bus->sysdata; + unsigned long flags; + u32 data; + + /* + * PCIPDR may only be accessed as 32 bit words, + * so we must do byte alignment by hand + */ + raw_spin_lock_irqsave(&pci_config_lock, flags); + pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR); + data = pci_read_reg(chan, SH4_PCIPDR); + raw_spin_unlock_irqrestore(&pci_config_lock, flags); + + switch (size) { + case 1: + *val = (data >> ((where & 3) << 3)) & 0xff; + break; + case 2: + *val = (data >> ((where & 2) << 3)) & 0xffff; + break; + case 4: + *val = data; + break; + default: + return PCIBIOS_FUNC_NOT_SUPPORTED; + } + + return PCIBIOS_SUCCESSFUL; +} + +/* + * Since SH4 only does 32bit access we'll have to do a read, + * mask,write operation. + * We'll allow an odd byte offset, though it should be illegal. + */ +static int sh4_pci_write(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + struct pci_channel *chan = bus->sysdata; + unsigned long flags; + int shift; + u32 data; + + raw_spin_lock_irqsave(&pci_config_lock, flags); + pci_write_reg(chan, CONFIG_CMD(bus, devfn, where), SH4_PCIPAR); + data = pci_read_reg(chan, SH4_PCIPDR); + raw_spin_unlock_irqrestore(&pci_config_lock, flags); + + switch (size) { + case 1: + shift = (where & 3) << 3; + data &= ~(0xff << shift); + data |= ((val & 0xff) << shift); + break; + case 2: + shift = (where & 2) << 3; + data &= ~(0xffff << shift); + data |= ((val & 0xffff) << shift); + break; + case 4: + data = val; + break; + default: + return PCIBIOS_FUNC_NOT_SUPPORTED; + } + + pci_write_reg(chan, data, SH4_PCIPDR); + + return PCIBIOS_SUCCESSFUL; +} + +struct pci_ops sh4_pci_ops = { + .read = sh4_pci_read, + .write = sh4_pci_write, +}; + +int __attribute__((weak)) pci_fixup_pcic(struct pci_channel *chan) +{ + /* Nothing to do. */ + return 0; +} |