/* * PMC-Sierra MSP board specific pci_ops * * Copyright 2001 MontaVista Software Inc. * Copyright 2005-2007 PMC-Sierra, Inc * * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net * * Much of the code is derived from the original DDB5074 port by * Geert Uytterhoeven * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * */ #define PCI_COUNTERS 1 #include #include #include #if defined(CONFIG_PROC_FS) && defined(PCI_COUNTERS) #include #include #endif /* CONFIG_PROC_FS && PCI_COUNTERS */ #include #include #include #if defined(CONFIG_PMC_MSP7120_GW) || defined(CONFIG_PMC_MSP7120_EVAL) #include #endif #include #include #include #include #include #define PCI_ACCESS_READ 0 #define PCI_ACCESS_WRITE 1 #if defined(CONFIG_PROC_FS) && defined(PCI_COUNTERS) static char proc_init; extern struct proc_dir_entry *proc_bus_pci_dir; unsigned int pci_int_count[32]; static void pci_proc_init(void); /***************************************************************************** * * FUNCTION: read_msp_pci_counts * _________________________________________________________________________ * * DESCRIPTION: Prints the count of how many times each PCI * interrupt has asserted. Can be invoked by the * /proc filesystem. * * INPUTS: page - part of STDOUT calculation * off - part of STDOUT calculation * count - part of STDOUT calculation * data - unused * * OUTPUTS: start - new start location * eof - end of file pointer * * RETURNS: len - STDOUT length * ****************************************************************************/ static int read_msp_pci_counts(char *page, char **start, off_t off, int count, int *eof, void *data) { int i; int len = 0; unsigned int intcount, total = 0; for (i = 0; i < 32; ++i) { intcount = pci_int_count[i]; if (intcount != 0) { len += sprintf(page + len, "[%d] = %u\n", i, intcount); total += intcount; } } len += sprintf(page + len, "total = %u\n", total); if (len <= off+count) *eof = 1; *start = page + off; len -= off; if (len > count) len = count; if (len < 0) len = 0; return len; } /***************************************************************************** * * FUNCTION: gen_pci_cfg_wr * _________________________________________________________________________ * * DESCRIPTION: Generates a configuration write cycle for debug purposes. * The IDSEL line asserted and location and data written are * immaterial. Just want to be able to prove that a * configuration write can be correctly generated on the * PCI bus. Intent is that this function by invocable from * the /proc filesystem. * * INPUTS: page - part of STDOUT calculation * off - part of STDOUT calculation * count - part of STDOUT calculation * data - unused * * OUTPUTS: start - new start location * eof - end of file pointer * * RETURNS: len - STDOUT length * ****************************************************************************/ static int gen_pci_cfg_wr(char *page, char **start, off_t off, int count, int *eof, void *data) { unsigned char where = 0; /* Write to static Device/Vendor ID */ unsigned char bus_num = 0; /* Bus 0 */ unsigned char dev_fn = 0xF; /* Arbitrary device number */ u32 wr_data = 0xFF00AA00; /* Arbitrary data */ struct msp_pci_regs *preg = (void *)PCI_BASE_REG; int len = 0; unsigned long value; int intr; len += sprintf(page + len, "PMC MSP PCI: Beginning\n"); if (proc_init == 0) { pci_proc_init(); proc_init = ~0; } len += sprintf(page + len, "PMC MSP PCI: Before Cfg Wr\n"); /* * Generate PCI Configuration Write Cycle */ /* Clear cause register bits */ preg->if_status = ~(BPCI_IFSTATUS_BC0F | BPCI_IFSTATUS_BC1F); /* Setup address that is to appear on PCI bus */ preg->config_addr = BPCI_CFGADDR_ENABLE | (bus_num << BPCI_CFGADDR_BUSNUM_SHF) | (dev_fn << BPCI_CFGADDR_FUNCTNUM_SHF) | (where & 0xFC); value = cpu_to_le32(wr_data); /* Launch the PCI configuration write cycle */ *PCI_CONFIG_SPACE_REG = value; /* * Check if the PCI configuration cycle (rd or wr) succeeded, by * checking the status bits for errors like master or target abort. */ intr = preg->if_status; len += sprintf(page + len, "PMC MSP PCI: After Cfg Wr\n"); /* Handle STDOUT calculations */ if (len <= off+count) *eof = 1; *start = page + off; len -= off; if (len > count) len = count; if (len < 0) len = 0; return len; } /***************************************************************************** * * FUNCTION: pci_proc_init * _________________________________________________________________________ * * DESCRIPTION: Create entries in the /proc filesystem for debug access. * * INPUTS: none * * OUTPUTS: none * * RETURNS: none * ****************************************************************************/ static void pci_proc_init(void) { create_proc_read_entry("pmc_msp_pci_rd_cnt", 0, NULL, read_msp_pci_counts, NULL); create_proc_read_entry("pmc_msp_pci_cfg_wr", 0, NULL, gen_pci_cfg_wr, NULL); } #endif /* CONFIG_PROC_FS && PCI_COUNTERS */ static DEFINE_SPINLOCK(bpci_lock); /***************************************************************************** * * STRUCT: pci_io_resource * _________________________________________________________________________ * * DESCRIPTION: Defines the address range that pciauto() will use to * assign to the I/O BARs of PCI devices. * * Use the start and end addresses of the MSP7120 PCI Host * Controller I/O space, in the form that they appear on the * PCI bus AFTER MSP7120 has performed address translation. * * For I/O accesses, MSP7120 ignores OATRAN and maps I/O * accesses into the bottom 0xFFF region of address space, * so that is the range to put into the pci_io_resource * struct. * * In MSP4200, the start address was 0x04 instead of the * expected 0x00. Will just assume there was a good reason * for this! * * NOTES: Linux, by default, will assign I/O space to the lowest * region of address space. Since MSP7120 and Linux, * by default, have no offset in between how they map, the * io_offset element of pci_controller struct should be set * to zero. * ELEMENTS: * name - String used for a meaningful name. * * start - Start address of MSP7120's I/O space, as MSP7120 presents * the address on the PCI bus. * * end - End address of MSP7120's I/O space, as MSP7120 presents * the address on the PCI bus. * * flags - Attributes indicating the type of resource. In this case, * indicate I/O space. * ****************************************************************************/ static struct resource pci_io_resource = { .name = "pci IO space", .start = 0x04, .end = 0x0FFF, .flags = IORESOURCE_IO /* I/O space */ }; /***************************************************************************** * * STRUCT: pci_mem_resource * _________________________________________________________________________ * * DESCRIPTION: Defines the address range that pciauto() will use to * assign to the memory BARs of PCI devices. * * The .start and .end values are dependent upon how address * translation is performed by the OATRAN regiser. * * The values to use for .start and .end are the values * in the form they appear on the PCI bus AFTER MSP7120 has * performed OATRAN address translation. * * ELEMENTS: * name - String used for a meaningful name. * * start - Start address of MSP7120's memory space, as MSP7120 presents * the address on the PCI bus. * * end - End address of MSP7120's memory space, as MSP7120 presents * the address on the PCI bus. * * flags - Attributes indicating the type of resource. In this case, * indicate memory space. * ****************************************************************************/ static struct resource pci_mem_resource = { .name = "pci memory space", .start = MSP_PCI_SPACE_BASE, .end = MSP_PCI_SPACE_END, .flags = IORESOURCE_MEM /* memory space */ }; /***************************************************************************** * * FUNCTION: bpci_interrupt * _________________________________________________________________________ * * DESCRIPTION: PCI status interrupt handler. Updates the count of how * many times each status bit has been set, then clears * the status bits. If the appropriate macros are defined, * these counts can be viewed via the /proc filesystem. * * INPUTS: irq - unused * dev_id - unused * pt_regs - unused * * OUTPUTS: none * * RETURNS: PCIBIOS_SUCCESSFUL - success * ****************************************************************************/ static int bpci_interrupt(int irq, void *dev_id) { struct msp_pci_regs *preg = (void *)PCI_BASE_REG; unsigned int stat = preg->if_status; #if defined(CONFIG_PROC_FS) && defined(PCI_COUNTERS) int i; for (i = 0; i < 32; ++i) { if ((1 << i) & stat) ++pci_int_count[i]; } #endif /* PROC_FS && PCI_COUNTERS */ /* printk("PCI ISR: Status=%08X\n", stat); */ /* write to clear all asserted interrupts */ preg->if_status = stat; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_config_access * _________________________________________________________________________ * * DESCRIPTION: Performs a PCI configuration access (rd or wr), then * checks that the access succeeded by querying MSP7120's * PCI status bits. * * INPUTS: * access_type - kind of PCI configuration cycle to perform * (read or write). Legal values are * PCI_ACCESS_WRITE and PCI_ACCESS_READ. * * bus - pointer to the bus number of the device to * be targetted for the configuration cycle. * The only element of the pci_bus structure * used is bus->number. This argument determines * if the configuration access will be Type 0 or * Type 1. Since MSP7120 assumes itself to be the * PCI Host, any non-zero bus->number generates * a Type 1 access. * * devfn - this is an 8-bit field. The lower three bits * specify the function number of the device to * be targetted for the configuration cycle, with * all three-bit combinations being legal. The * upper five bits specify the device number, * with legal values being 10 to 31. * * where - address within the Configuration Header * space to access. * * data - for write accesses, contains the data to * write. * * OUTPUTS: * data - for read accesses, contains the value read. * * RETURNS: PCIBIOS_SUCCESSFUL - success * -1 - access failure * ****************************************************************************/ int msp_pcibios_config_access(unsigned char access_type, struct pci_bus *bus, unsigned int devfn, unsigned char where, u32 *data) { struct msp_pci_regs *preg = (void *)PCI_BASE_REG; unsigned char bus_num = bus->number; unsigned char dev_fn = (unsigned char)devfn; unsigned long flags; unsigned long intr; unsigned long value; static char pciirqflag; int ret; #if defined(CONFIG_PMC_MSP7120_GW) || defined(CONFIG_PMC_MSP7120_EVAL) unsigned int vpe_status; #endif #if defined(CONFIG_PROC_FS) && defined(PCI_COUNTERS) if (proc_init == 0) { pci_proc_init(); proc_init = ~0; } #endif /* CONFIG_PROC_FS && PCI_COUNTERS */ /* * Just the first time this function invokes, allocate * an interrupt line for PCI host status interrupts. The * allocation assigns an interrupt handler to the interrupt. */ if (pciirqflag == 0) { ret = request_irq(MSP_INT_PCI,/* Hardcoded internal MSP7120 wiring */ bpci_interrupt, IRQF_SHARED | IRQF_DISABLED, "PMC MSP PCI Host", preg); if (ret != 0) return ret; pciirqflag = ~0; } #if defined(CONFIG_PMC_MSP7120_GW) || defined(CONFIG_PMC_MSP7120_EVAL) local_irq_save(flags); vpe_status = dvpe(); #else spin_lock_irqsave(&bpci_lock, flags); #endif /* * Clear PCI cause register bits. * * In Polo, the PCI Host had a dedicated DMA called the * Block Copy (not to be confused with the general purpose Block * Copy Engine block). There appear to have been special interrupts * for this Block Copy, called Block Copy 0 Fault (BC0F) and * Block Copy 1 Fault (BC1F). MSP4200 and MSP7120 don't have this * dedicated Block Copy block, so these two interrupts are now * marked reserved. In case the Block Copy is resurrected in a * future design, maintain the code that treats these two interrupts * specially. * * Write to clear all interrupts in the PCI status register, aside * from BC0F and BC1F. */ preg->if_status = ~(BPCI_IFSTATUS_BC0F | BPCI_IFSTATUS_BC1F); /* Setup address that is to appear on PCI bus */ preg->config_addr = BPCI_CFGADDR_ENABLE | (bus_num << BPCI_CFGADDR_BUSNUM_SHF) | (dev_fn << BPCI_CFGADDR_FUNCTNUM_SHF) | (where & 0xFC); /* IF access is a PCI configuration write */ if (access_type == PCI_ACCESS_WRITE) { value = cpu_to_le32(*data); *PCI_CONFIG_SPACE_REG = value; } else { /* ELSE access is a PCI configuration read */ value = le32_to_cpu(*PCI_CONFIG_SPACE_REG); *data = value; } /* * Check if the PCI configuration cycle (rd or wr) succeeded, by * checking the status bits for errors like master or target abort. */ intr = preg->if_status; /* Clear config access */ preg->config_addr = 0; /* IF error occurred */ if (intr & ~(BPCI_IFSTATUS_BC0F | BPCI_IFSTATUS_BC1F)) { /* Clear status bits */ preg->if_status = ~(BPCI_IFSTATUS_BC0F | BPCI_IFSTATUS_BC1F); #if defined(CONFIG_PMC_MSP7120_GW) || defined(CONFIG_PMC_MSP7120_EVAL) evpe(vpe_status); local_irq_restore(flags); #else spin_unlock_irqrestore(&bpci_lock, flags); #endif return -1; } #if defined(CONFIG_PMC_MSP7120_GW) || defined(CONFIG_PMC_MSP7120_EVAL) evpe(vpe_status); local_irq_restore(flags); #else spin_unlock_irqrestore(&bpci_lock, flags); #endif return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_read_config_byte * _________________________________________________________________________ * * DESCRIPTION: Read a byte from PCI configuration address spac * Since the hardware can't address 8 bit chunks * directly, read a 32-bit chunk, then mask off extraneous * bits. * * INPUTS bus - structure containing attributes for the PCI bus * that the read is destined for. * devfn - device/function combination that the read is * destined for. * where - register within the Configuration Header space * to access. * * OUTPUTS val - read data * * RETURNS: PCIBIOS_SUCCESSFUL - success * -1 - read access failure * ****************************************************************************/ static int msp_pcibios_read_config_byte(struct pci_bus *bus, unsigned int devfn, int where, u32 *val) { u32 data = 0; /* * If the config access did not complete normally (e.g., underwent * master abort) do the PCI compliant thing, which is to supply an * all ones value. */ if (msp_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) { *val = 0xFFFFFFFF; return -1; } *val = (data >> ((where & 3) << 3)) & 0x0ff; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_read_config_word * _________________________________________________________________________ * * DESCRIPTION: Read a word (16 bits) from PCI configuration address space. * Since the hardware can't address 16 bit chunks * directly, read a 32-bit chunk, then mask off extraneous * bits. * * INPUTS bus - structure containing attributes for the PCI bus * that the read is destined for. * devfn - device/function combination that the read is * destined for. * where - register within the Configuration Header space * to access. * * OUTPUTS val - read data * * RETURNS: PCIBIOS_SUCCESSFUL - success * PCIBIOS_BAD_REGISTER_NUMBER - bad register address * -1 - read access failure * ****************************************************************************/ static int msp_pcibios_read_config_word(struct pci_bus *bus, unsigned int devfn, int where, u32 *val) { u32 data = 0; /* if (where & 1) */ /* Commented out non-compliant code. * Should allow word access to configuration * registers, with only exception being when * the word access would wrap around into * the next dword. */ if ((where & 3) == 3) { *val = 0xFFFFFFFF; return PCIBIOS_BAD_REGISTER_NUMBER; } /* * If the config access did not complete normally (e.g., underwent * master abort) do the PCI compliant thing, which is to supply an * all ones value. */ if (msp_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) { *val = 0xFFFFFFFF; return -1; } *val = (data >> ((where & 3) << 3)) & 0x0ffff; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_read_config_dword * _________________________________________________________________________ * * DESCRIPTION: Read a double word (32 bits) from PCI configuration * address space. * * INPUTS bus - structure containing attributes for the PCI bus * that the read is destined for. * devfn - device/function combination that the read is * destined for. * where - register within the Configuration Header space * to access. * * OUTPUTS val - read data * * RETURNS: PCIBIOS_SUCCESSFUL - success * PCIBIOS_BAD_REGISTER_NUMBER - bad register address * -1 - read access failure * ****************************************************************************/ static int msp_pcibios_read_config_dword(struct pci_bus *bus, unsigned int devfn, int where, u32 *val) { u32 data = 0; /* Address must be dword aligned. */ if (where & 3) { *val = 0xFFFFFFFF; return PCIBIOS_BAD_REGISTER_NUMBER; } /* * If the config access did not complete normally (e.g., underwent * master abort) do the PCI compliant thing, which is to supply an * all ones value. */ if (msp_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) { *val = 0xFFFFFFFF; return -1; } *val = data; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_write_config_byte * _________________________________________________________________________ * * DESCRIPTION: Write a byte to PCI configuration address space. * Since the hardware can't address 8 bit chunks * directly, a read-modify-write is performed. * * INPUTS bus - structure containing attributes for the PCI bus * that the write is destined for. * devfn - device/function combination that the write is * destined for. * where - register within the Configuration Header space * to access. * val - value to write * * OUTPUTS none * * RETURNS: PCIBIOS_SUCCESSFUL - success * -1 - write access failure * ****************************************************************************/ static int msp_pcibios_write_config_byte(struct pci_bus *bus, unsigned int devfn, int where, u8 val) { u32 data = 0; /* read config space */ if (msp_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) return -1; /* modify the byte within the dword */ data = (data & ~(0xff << ((where & 3) << 3))) | (val << ((where & 3) << 3)); /* write back the full dword */ if (msp_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data)) return -1; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_write_config_word * _________________________________________________________________________ * * DESCRIPTION: Write a word (16-bits) to PCI configuration address space. * Since the hardware can't address 16 bit chunks * directly, a read-modify-write is performed. * * INPUTS bus - structure containing attributes for the PCI bus * that the write is destined for. * devfn - device/function combination that the write is * destined for. * where - register within the Configuration Header space * to access. * val - value to write * * OUTPUTS none * * RETURNS: PCIBIOS_SUCCESSFUL - success * PCIBIOS_BAD_REGISTER_NUMBER - bad register address * -1 - write access failure * ****************************************************************************/ static int msp_pcibios_write_config_word(struct pci_bus *bus, unsigned int devfn, int where, u16 val) { u32 data = 0; /* Fixed non-compliance: if (where & 1) */ if ((where & 3) == 3) return PCIBIOS_BAD_REGISTER_NUMBER; /* read config space */ if (msp_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where, &data)) return -1; /* modify the word within the dword */ data = (data & ~(0xffff << ((where & 3) << 3))) | (val << ((where & 3) << 3)); /* write back the full dword */ if (msp_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data)) return -1; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_write_config_dword * _________________________________________________________________________ * * DESCRIPTION: Write a double word (32-bits) to PCI configuration address * space. * * INPUTS bus - structure containing attributes for the PCI bus * that the write is destined for. * devfn - device/function combination that the write is * destined for. * where - register within the Configuration Header space * to access. * val - value to write * * OUTPUTS none * * RETURNS: PCIBIOS_SUCCESSFUL - success * PCIBIOS_BAD_REGISTER_NUMBER - bad register address * -1 - write access failure * ****************************************************************************/ static int msp_pcibios_write_config_dword(struct pci_bus *bus, unsigned int devfn, int where, u32 val) { /* check that address is dword aligned */ if (where & 3) return PCIBIOS_BAD_REGISTER_NUMBER; /* perform write */ if (msp_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val)) return -1; return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_read_config * _________________________________________________________________________ * * DESCRIPTION: Interface the PCI configuration read request with * the appropriate function, based on how many bytes * the read request is. * * INPUTS bus - structure containing attributes for the PCI bus * that the write is destined for. * devfn - device/function combination that the write is * destined for. * where - register within the Configuration Header space * to access. * size - in units of bytes, should be 1, 2, or 4. * * OUTPUTS val - value read, with any extraneous bytes masked * to zero. * * RETURNS: PCIBIOS_SUCCESSFUL - success * -1 - failure * ****************************************************************************/ int msp_pcibios_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) { if (size == 1) { if (msp_pcibios_read_config_byte(bus, devfn, where, val)) { return -1; } } else if (size == 2) { if (msp_pcibios_read_config_word(bus, devfn, where, val)) { return -1; } } else if (size == 4) { if (msp_pcibios_read_config_dword(bus, devfn, where, val)) { return -1; } } else { *val = 0xFFFFFFFF; return -1; } return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * FUNCTION: msp_pcibios_write_config * _________________________________________________________________________ * * DESCRIPTION: Interface the PCI configuration write request with * the appropriate function, based on how many bytes * the read request is. * * INPUTS bus - structure containing attributes for the PCI bus * that the write is destined for. * devfn - device/function combination that the write is * destined for. * where - register within the Configuration Header space * to access. * size - in units of bytes, should be 1, 2, or 4. * val - value to write * * OUTPUTS: none * * RETURNS: PCIBIOS_SUCCESSFUL - success * -1 - failure * ****************************************************************************/ int msp_pcibios_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) { if (size == 1) { if (msp_pcibios_write_config_byte(bus, devfn, where, (u8)(0xFF & val))) { return -1; } } else if (size == 2) { if (msp_pcibios_write_config_word(bus, devfn, where, (u16)(0xFFFF & val))) { return -1; } } else if (size == 4) { if (msp_pcibios_write_config_dword(bus, devfn, where, val)) { return -1; } } else { return -1; } return PCIBIOS_SUCCESSFUL; } /***************************************************************************** * * STRUCTURE: msp_pci_ops * _________________________________________________________________________ * * DESCRIPTION: structure to abstract the hardware specific PCI * configuration accesses. * * ELEMENTS: * read - function for Linux to generate PCI Configuration reads. * write - function for Linux to generate PCI Configuration writes. * ****************************************************************************/ struct pci_ops msp_pci_ops = { .read = msp_pcibios_read_config, .write = msp_pcibios_write_config }; /***************************************************************************** * * STRUCTURE: msp_pci_controller * _________________________________________________________________________ * * Describes the attributes of the MSP7120 PCI Host Controller * * ELEMENTS: * pci_ops - abstracts the hardware specific PCI configuration * accesses. * * mem_resource - address range pciauto() uses to assign to PCI device * memory BARs. * * mem_offset - offset between how MSP7120 outbound PCI memory * transaction addresses appear on the PCI bus and how Linux * wants to configure memory BARs of the PCI devices. * MSP7120 does nothing funky, so just set to zero. * * io_resource - address range pciauto() uses to assign to PCI device * I/O BARs. * * io_offset - offset between how MSP7120 outbound PCI I/O * transaction addresses appear on the PCI bus and how * Linux defaults to configure I/O BARs of the PCI devices. * MSP7120 maps outbound I/O accesses into the bottom * bottom 4K of PCI address space (and ignores OATRAN). * Since the Linux default is to configure I/O BARs to the * bottom 4K, no special offset is needed. Just set to zero. * ****************************************************************************/ static struct pci_controller msp_pci_controller = { .pci_ops = &msp_pci_ops, .mem_resource = &pci_mem_resource, .mem_offset = 0, .io_map_base = MSP_PCI_IOSPACE_BASE, .io_resource = &pci_io_resource, .io_offset = 0 }; /***************************************************************************** * * FUNCTION: msp_pci_init * _________________________________________________________________________ * * DESCRIPTION: Initialize the PCI Host Controller and register it with * Linux so Linux can seize control of the PCI bus. * ****************************************************************************/ void __init msp_pci_init(void) { struct msp_pci_regs *preg = (void *)PCI_BASE_REG; u32 id; /* Extract Device ID */ id = read_reg32(PCI_JTAG_DEVID_REG, 0xFFFF) >> 12; /* Check if JTAG ID identifies MSP7120 */ if (!MSP_HAS_PCI(id)) { printk(KERN_WARNING "PCI: No PCI; id reads as %x\n", id); goto no_pci; } /* * Enable flushing of the PCI-SDRAM queue upon a read * of the SDRAM's Memory Configuration Register. */ *(unsigned long *)QFLUSH_REG_1 = 3; /* Configure PCI Host Controller. */ preg->if_status = ~0; /* Clear cause register bits */ preg->config_addr = 0; /* Clear config access */ preg->oatran = MSP_PCI_OATRAN; /* PCI outbound addr translation */ preg->if_mask = 0xF8BF87C0; /* Enable all PCI status interrupts */ /* configure so inb(), outb(), and family are functional */ set_io_port_base(MSP_PCI_IOSPACE_BASE); /* Tell Linux the details of the MSP7120 PCI Host Controller */ register_pci_controller(&msp_pci_controller); return; no_pci: /* Disable PCI channel */ printk(KERN_WARNING "PCI: no host PCI bus detected\n"); }