diff options
Diffstat (limited to 'drivers/firewire/init_ohci1394_dma.c')
| -rw-r--r-- | drivers/firewire/init_ohci1394_dma.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/firewire/init_ohci1394_dma.c b/drivers/firewire/init_ohci1394_dma.c new file mode 100644 index 00000000000..a9a347adb35 --- /dev/null +++ b/drivers/firewire/init_ohci1394_dma.c @@ -0,0 +1,309 @@ +/* + * init_ohci1394_dma.c - Initializes physical DMA on all OHCI 1394 controllers + * + * Copyright (C) 2006-2007 Bernhard Kaindl <bk@suse.de> + * + * Derived from drivers/ieee1394/ohci1394.c and arch/x86/kernel/early-quirks.c + * this file has functions to: + * - scan the PCI very early on boot for all OHCI 1394-compliant controllers + * - reset and initialize them and make them join the IEEE1394 bus and + * - enable physical DMA on them to allow remote debugging + * + * All code and data is marked as __init and __initdata, respective as + * during boot, all OHCI1394 controllers may be claimed by the firewire + * stack and at this point, this code should not touch them anymore. + * + * To use physical DMA after the initialization of the firewire stack, + * be sure that the stack enables it and (re-)attach after the bus reset + * which may be caused by the firewire stack initialization. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/pci.h> /* for PCI defines */ +#include <linux/string.h> + +#include <asm/pci-direct.h> /* for direct PCI config space access */ +#include <asm/fixmap.h> + +#include <linux/init_ohci1394_dma.h> +#include "ohci.h" + +int __initdata init_ohci1394_dma_early; + +struct ohci { + void __iomem *registers; +}; + +static inline void reg_write(const struct ohci *ohci, int offset, u32 data) +{ + writel(data, ohci->registers + offset); +} + +static inline u32 reg_read(const struct ohci *ohci, int offset) +{ + return readl(ohci->registers + offset); +} + +#define OHCI_LOOP_COUNT 100 /* Number of loops for reg read waits */ + +/* Reads a PHY register of an OHCI-1394 controller */ +static inline u8 __init get_phy_reg(struct ohci *ohci, u8 addr) +{ + int i; + u32 r; + + reg_write(ohci, OHCI1394_PhyControl, (addr << 8) | 0x00008000); + + for (i = 0; i < OHCI_LOOP_COUNT; i++) { + if (reg_read(ohci, OHCI1394_PhyControl) & 0x80000000) + break; + mdelay(1); + } + r = reg_read(ohci, OHCI1394_PhyControl); + + return (r & 0x00ff0000) >> 16; +} + +/* Writes to a PHY register of an OHCI-1394 controller */ +static inline void __init set_phy_reg(struct ohci *ohci, u8 addr, u8 data) +{ + int i; + + reg_write(ohci, OHCI1394_PhyControl, (addr << 8) | data | 0x00004000); + + for (i = 0; i < OHCI_LOOP_COUNT; i++) { + if (!(reg_read(ohci, OHCI1394_PhyControl) & 0x00004000)) + break; + mdelay(1); + } +} + +/* Resets an OHCI-1394 controller (for sane state before initialization) */ +static inline void __init init_ohci1394_soft_reset(struct ohci *ohci) +{ + int i; + + reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset); + + for (i = 0; i < OHCI_LOOP_COUNT; i++) { + if (!(reg_read(ohci, OHCI1394_HCControlSet) + & OHCI1394_HCControl_softReset)) + break; + mdelay(1); + } +} + +#define OHCI1394_MAX_AT_REQ_RETRIES 0xf +#define OHCI1394_MAX_AT_RESP_RETRIES 0x2 +#define OHCI1394_MAX_PHYS_RESP_RETRIES 0x8 + +/* Basic OHCI-1394 register and port inititalization */ +static inline void __init init_ohci1394_initialize(struct ohci *ohci) +{ + u32 bus_options; + int num_ports, i; + + /* Put some defaults to these undefined bus options */ + bus_options = reg_read(ohci, OHCI1394_BusOptions); + bus_options |= 0x60000000; /* Enable CMC and ISC */ + bus_options &= ~0x00ff0000; /* XXX: Set cyc_clk_acc to zero for now */ + bus_options &= ~0x18000000; /* Disable PMC and BMC */ + reg_write(ohci, OHCI1394_BusOptions, bus_options); + + /* Set the bus number */ + reg_write(ohci, OHCI1394_NodeID, 0x0000ffc0); + + /* Enable posted writes */ + reg_write(ohci, OHCI1394_HCControlSet, + OHCI1394_HCControl_postedWriteEnable); + + /* Clear link control register */ + reg_write(ohci, OHCI1394_LinkControlClear, 0xffffffff); + + /* enable phys */ + reg_write(ohci, OHCI1394_LinkControlSet, + OHCI1394_LinkControl_rcvPhyPkt); + + /* Don't accept phy packets into AR request context */ + reg_write(ohci, OHCI1394_LinkControlClear, 0x00000400); + + /* Clear the Isochonouys interrupt masks */ + reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 0xffffffff); + reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 0xffffffff); + reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 0xffffffff); + reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 0xffffffff); + + /* Accept asyncronous transfer requests from all nodes for now */ + reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000); + + /* Specify asyncronous transfer retries */ + reg_write(ohci, OHCI1394_ATRetries, + OHCI1394_MAX_AT_REQ_RETRIES | + (OHCI1394_MAX_AT_RESP_RETRIES<<4) | + (OHCI1394_MAX_PHYS_RESP_RETRIES<<8)); + + /* We don't want hardware swapping */ + reg_write(ohci, OHCI1394_HCControlClear, + OHCI1394_HCControl_noByteSwapData); + + /* Enable link */ + reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_linkEnable); + + /* If anything is connected to a port, make sure it is enabled */ + num_ports = get_phy_reg(ohci, 2) & 0xf; + for (i = 0; i < num_ports; i++) { + unsigned int status; + + set_phy_reg(ohci, 7, i); + status = get_phy_reg(ohci, 8); + + if (status & 0x20) + set_phy_reg(ohci, 8, status & ~1); + } +} + +/** + * init_ohci1394_wait_for_busresets - wait until bus resets are completed + * + * OHCI1394 initialization itself and any device going on- or offline + * and any cable issue cause a IEEE1394 bus reset. The OHCI1394 spec + * specifies that physical DMA is disabled on each bus reset and it + * has to be enabled after each bus reset when needed. We resort + * to polling here because on early boot, we have no interrupts. + */ +static inline void __init init_ohci1394_wait_for_busresets(struct ohci *ohci) +{ + int i, events; + + for (i = 0; i < 9; i++) { + mdelay(200); + events = reg_read(ohci, OHCI1394_IntEventSet); + if (events & OHCI1394_busReset) + reg_write(ohci, OHCI1394_IntEventClear, + OHCI1394_busReset); + } +} + +/** + * init_ohci1394_enable_physical_dma - Enable physical DMA for remote debugging + * This enables remote DMA access over IEEE1394 from every host for the low + * 4GB of address space. DMA accesses above 4GB are not available currently. + */ +static inline void __init init_ohci1394_enable_physical_dma(struct ohci *ohci) +{ + reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 0xffffffff); + reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 0xffffffff); + reg_write(ohci, OHCI1394_PhyUpperBound, 0xffff0000); +} + +/** + * init_ohci1394_reset_and_init_dma - init controller and enable DMA + * This initializes the given controller and enables physical DMA engine in it. + */ +static inline void __init init_ohci1394_reset_and_init_dma(struct ohci *ohci) +{ + /* Start off with a soft reset, clears everything to a sane state. */ + init_ohci1394_soft_reset(ohci); + + /* Accessing some registers without LPS enabled may cause lock up */ + reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_LPS); + + /* Disable and clear interrupts */ + reg_write(ohci, OHCI1394_IntEventClear, 0xffffffff); + reg_write(ohci, OHCI1394_IntMaskClear, 0xffffffff); + + mdelay(50); /* Wait 50msec to make sure we have full link enabled */ + + init_ohci1394_initialize(ohci); + /* + * The initialization causes at least one IEEE1394 bus reset. Enabling + * physical DMA only works *after* *all* bus resets have calmed down: + */ + init_ohci1394_wait_for_busresets(ohci); + + /* We had to wait and do this now if we want to debug early problems */ + init_ohci1394_enable_physical_dma(ohci); +} + +/** + * init_ohci1394_controller - Map the registers of the controller and init DMA + * This maps the registers of the specified controller and initializes it + */ +static inline void __init init_ohci1394_controller(int num, int slot, int func) +{ + unsigned long ohci_base; + struct ohci ohci; + + printk(KERN_INFO "init_ohci1394_dma: initializing OHCI-1394" + " at %02x:%02x.%x\n", num, slot, func); + + ohci_base = read_pci_config(num, slot, func, PCI_BASE_ADDRESS_0+(0<<2)) + & PCI_BASE_ADDRESS_MEM_MASK; + + set_fixmap_nocache(FIX_OHCI1394_BASE, ohci_base); + + ohci.registers = (void __iomem *)fix_to_virt(FIX_OHCI1394_BASE); + + init_ohci1394_reset_and_init_dma(&ohci); +} + +/** + * debug_init_ohci1394_dma - scan for OHCI1394 controllers and init DMA on them + * Scans the whole PCI space for OHCI1394 controllers and inits DMA on them + */ +void __init init_ohci1394_dma_on_all_controllers(void) +{ + int num, slot, func; + u32 class; + + if (!early_pci_allowed()) + return; + + /* Poor man's PCI discovery, the only thing we can do at early boot */ + for (num = 0; num < 32; num++) { + for (slot = 0; slot < 32; slot++) { + for (func = 0; func < 8; func++) { + class = read_pci_config(num, slot, func, + PCI_CLASS_REVISION); + if (class == 0xffffffff) + continue; /* No device at this func */ + + if (class>>8 != PCI_CLASS_SERIAL_FIREWIRE_OHCI) + continue; /* Not an OHCI-1394 device */ + + init_ohci1394_controller(num, slot, func); + break; /* Assume one controller per device */ + } + } + } + printk(KERN_INFO "init_ohci1394_dma: finished initializing OHCI DMA\n"); +} + +/** + * setup_init_ohci1394_early - enables early OHCI1394 DMA initialization + */ +static int __init setup_ohci1394_dma(char *opt) +{ + if (!strcmp(opt, "early")) + init_ohci1394_dma_early = 1; + return 0; +} + +/* passing ohci1394_dma=early on boot causes early OHCI1394 DMA initialization */ +early_param("ohci1394_dma", setup_ohci1394_dma); |