diff options
Diffstat (limited to 'arch/x86/pci/olpc.c')
| -rw-r--r-- | arch/x86/pci/olpc.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/arch/x86/pci/olpc.c b/arch/x86/pci/olpc.c new file mode 100644 index 000000000000..5e7636558c02 --- /dev/null +++ b/arch/x86/pci/olpc.c @@ -0,0 +1,313 @@ +/* + * Low-level PCI config space access for OLPC systems who lack the VSA + * PCI virtualization software. + * + * Copyright © 2006 Advanced Micro Devices, Inc. + * + * 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. + * + * The AMD Geode chipset (ie: GX2 processor, cs5536 I/O companion device) + * has some I/O functions (display, southbridge, sound, USB HCIs, etc) + * that more or less behave like PCI devices, but the hardware doesn't + * directly implement the PCI configuration space headers. AMD provides + * "VSA" (Virtual System Architecture) software that emulates PCI config + * space for these devices, by trapping I/O accesses to PCI config register + * (CF8/CFC) and running some code in System Management Mode interrupt state. + * On the OLPC platform, we don't want to use that VSA code because + * (a) it slows down suspend/resume, and (b) recompiling it requires special + * compilers that are hard to get. So instead of letting the complex VSA + * code simulate the PCI config registers for the on-chip devices, we + * just simulate them the easy way, by inserting the code into the + * pci_write_config and pci_read_config path. Most of the config registers + * are read-only anyway, so the bulk of the simulation is just table lookup. + */ + +#include <linux/pci.h> +#include <linux/init.h> +#include <asm/olpc.h> +#include <asm/geode.h> +#include "pci.h" + +/* + * In the tables below, the first two line (8 longwords) are the + * size masks that are used when the higher level PCI code determines + * the size of the region by writing ~0 to a base address register + * and reading back the result. + * + * The following lines are the values that are read during normal + * PCI config access cycles, i.e. not after just having written + * ~0 to a base address register. + */ + +static const uint32_t lxnb_hdr[] = { /* dev 1 function 0 - devfn = 8 */ + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x281022, 0x2200005, 0x6000021, 0x80f808, /* AMD Vendor ID */ + 0x0, 0x0, 0x0, 0x0, /* No virtual registers, hence no BAR */ + 0x0, 0x0, 0x0, 0x28100b, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t gxnb_hdr[] = { /* dev 1 function 0 - devfn = 8 */ + 0xfffffffd, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x28100b, 0x2200005, 0x6000021, 0x80f808, /* NSC Vendor ID */ + 0xac1d, 0x0, 0x0, 0x0, /* I/O BAR - base of virtual registers */ + 0x0, 0x0, 0x0, 0x28100b, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t lxfb_hdr[] = { /* dev 1 function 1 - devfn = 9 */ + 0xff000008, 0xffffc000, 0xffffc000, 0xffffc000, + 0xffffc000, 0x0, 0x0, 0x0, + + 0x20811022, 0x2200003, 0x3000000, 0x0, /* AMD Vendor ID */ + 0xfd000000, 0xfe000000, 0xfe004000, 0xfe008000, /* FB, GP, VG, DF */ + 0xfe00c000, 0x0, 0x0, 0x30100b, /* VIP */ + 0x0, 0x0, 0x0, 0x10e, /* INTA, IRQ14 for graphics accel */ + 0x0, 0x0, 0x0, 0x0, + 0x3d0, 0x3c0, 0xa0000, 0x0, /* VG IO, VG IO, EGA FB, MONO FB */ + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t gxfb_hdr[] = { /* dev 1 function 1 - devfn = 9 */ + 0xff800008, 0xffffc000, 0xffffc000, 0xffffc000, + 0x0, 0x0, 0x0, 0x0, + + 0x30100b, 0x2200003, 0x3000000, 0x0, /* NSC Vendor ID */ + 0xfd000000, 0xfe000000, 0xfe004000, 0xfe008000, /* FB, GP, VG, DF */ + 0x0, 0x0, 0x0, 0x30100b, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x3d0, 0x3c0, 0xa0000, 0x0, /* VG IO, VG IO, EGA FB, MONO FB */ + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t aes_hdr[] = { /* dev 1 function 2 - devfn = 0xa */ + 0xffffc000, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x20821022, 0x2a00006, 0x10100000, 0x8, /* NSC Vendor ID */ + 0xfe010000, 0x0, 0x0, 0x0, /* AES registers */ + 0x0, 0x0, 0x0, 0x20821022, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, +}; + + +static const uint32_t isa_hdr[] = { /* dev f function 0 - devfn = 78 */ + 0xfffffff9, 0xffffff01, 0xffffffc1, 0xffffffe1, + 0xffffff81, 0xffffffc1, 0x0, 0x0, + + 0x20901022, 0x2a00049, 0x6010003, 0x802000, + 0x18b1, 0x1001, 0x1801, 0x1881, /* SMB-8 GPIO-256 MFGPT-64 IRQ-32 */ + 0x1401, 0x1841, 0x0, 0x20901022, /* PMS-128 ACPI-64 */ + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0xaa5b, /* IRQ steering */ + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t ac97_hdr[] = { /* dev f function 3 - devfn = 7b */ + 0xffffff81, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x20931022, 0x2a00041, 0x4010001, 0x0, + 0x1481, 0x0, 0x0, 0x0, /* I/O BAR-128 */ + 0x0, 0x0, 0x0, 0x20931022, + 0x0, 0x0, 0x0, 0x205, /* IntB, IRQ5 */ + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t ohci_hdr[] = { /* dev f function 4 - devfn = 7c */ + 0xfffff000, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x20941022, 0x2300006, 0xc031002, 0x0, + 0xfe01a000, 0x0, 0x0, 0x0, /* MEMBAR-1000 */ + 0x0, 0x0, 0x0, 0x20941022, + 0x0, 0x40, 0x0, 0x40a, /* CapPtr INT-D, IRQA */ + 0xc8020001, 0x0, 0x0, 0x0, /* Capabilities - 40 is R/O, + 44 is mask 8103 (power control) */ + 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, +}; + +static const uint32_t ehci_hdr[] = { /* dev f function 4 - devfn = 7d */ + 0xfffff000, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, + + 0x20951022, 0x2300006, 0xc032002, 0x0, + 0xfe01b000, 0x0, 0x0, 0x0, /* MEMBAR-1000 */ + 0x0, 0x0, 0x0, 0x20951022, + 0x0, 0x40, 0x0, 0x40a, /* CapPtr INT-D, IRQA */ + 0xc8020001, 0x0, 0x0, 0x0, /* Capabilities - 40 is R/O, 44 is + mask 8103 (power control) */ +#if 0 + 0x1, 0x40080000, 0x0, 0x0, /* EECP - see EHCI spec section 2.1.7 */ +#endif + 0x01000001, 0x0, 0x0, 0x0, /* EECP - see EHCI spec section 2.1.7 */ + 0x2020, 0x0, 0x0, 0x0, /* (EHCI page 8) 60 SBRN (R/O), + 61 FLADJ (R/W), PORTWAKECAP */ +}; + +static uint32_t ff_loc = ~0; +static uint32_t zero_loc; +static int bar_probing; /* Set after a write of ~0 to a BAR */ +static int is_lx; + +#define NB_SLOT 0x1 /* Northbridge - GX chip - Device 1 */ +#define SB_SLOT 0xf /* Southbridge - CS5536 chip - Device F */ + +static int is_simulated(unsigned int bus, unsigned int devfn) +{ + return (!bus && ((PCI_SLOT(devfn) == NB_SLOT) || + (PCI_SLOT(devfn) == SB_SLOT))); +} + +static uint32_t *hdr_addr(const uint32_t *hdr, int reg) +{ + uint32_t addr; + + /* + * This is a little bit tricky. The header maps consist of + * 0x20 bytes of size masks, followed by 0x70 bytes of header data. + * In the normal case, when not probing a BAR's size, we want + * to access the header data, so we add 0x20 to the reg offset, + * thus skipping the size mask area. + * In the BAR probing case, we want to access the size mask for + * the BAR, so we subtract 0x10 (the config header offset for + * BAR0), and don't skip the size mask area. + */ + + addr = (uint32_t)hdr + reg + (bar_probing ? -0x10 : 0x20); + + bar_probing = 0; + return (uint32_t *)addr; +} + +static int pci_olpc_read(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, uint32_t *value) +{ + uint32_t *addr; + + /* Use the hardware mechanism for non-simulated devices */ + if (!is_simulated(bus, devfn)) + return pci_direct_conf1.read(seg, bus, devfn, reg, len, value); + + /* + * No device has config registers past 0x70, so we save table space + * by not storing entries for the nonexistent registers + */ + if (reg >= 0x70) + addr = &zero_loc; + else { + switch (devfn) { + case 0x8: + addr = hdr_addr(is_lx ? lxnb_hdr : gxnb_hdr, reg); + break; + case 0x9: + addr = hdr_addr(is_lx ? lxfb_hdr : gxfb_hdr, reg); + break; + case 0xa: + addr = is_lx ? hdr_addr(aes_hdr, reg) : &ff_loc; + break; + case 0x78: + addr = hdr_addr(isa_hdr, reg); + break; + case 0x7b: + addr = hdr_addr(ac97_hdr, reg); + break; + case 0x7c: + addr = hdr_addr(ohci_hdr, reg); + break; + case 0x7d: + addr = hdr_addr(ehci_hdr, reg); + break; + default: + addr = &ff_loc; + break; + } + } + switch (len) { + case 1: + *value = *(uint8_t *)addr; + break; + case 2: + *value = *(uint16_t *)addr; + break; + case 4: + *value = *addr; + break; + default: + BUG(); + } + + return 0; +} + +static int pci_olpc_write(unsigned int seg, unsigned int bus, + unsigned int devfn, int reg, int len, uint32_t value) +{ + /* Use the hardware mechanism for non-simulated devices */ + if (!is_simulated(bus, devfn)) + return pci_direct_conf1.write(seg, bus, devfn, reg, len, value); + + /* XXX we may want to extend this to simulate EHCI power management */ + + /* + * Mostly we just discard writes, but if the write is a size probe + * (i.e. writing ~0 to a BAR), we remember it and arrange to return + * the appropriate size mask on the next read. This is cheating + * to some extent, because it depends on the fact that the next + * access after such a write will always be a read to the same BAR. + */ + + if ((reg >= 0x10) && (reg < 0x2c)) { + /* write is to a BAR */ + if (value == ~0) + bar_probing = 1; + } else { + /* + * No warning on writes to ROM BAR, CMD, LATENCY_TIMER, + * CACHE_LINE_SIZE, or PM registers. + */ + if ((reg != PCI_ROM_ADDRESS) && (reg != PCI_COMMAND_MASTER) && + (reg != PCI_LATENCY_TIMER) && + (reg != PCI_CACHE_LINE_SIZE) && (reg != 0x44)) + printk(KERN_WARNING "OLPC PCI: Config write to devfn" + " %x reg %x value %x\n", devfn, reg, value); + } + + return 0; +} + +static struct pci_raw_ops pci_olpc_conf = { + .read = pci_olpc_read, + .write = pci_olpc_write, +}; + +void __init pci_olpc_init(void) +{ + if (!machine_is_olpc() || olpc_has_vsa()) + return; + + printk(KERN_INFO "PCI: Using configuration type OLPC\n"); + raw_pci_ops = &pci_olpc_conf; + is_lx = is_geode_lx(); +} |