// SPDX-License-Identifier: GPL-2.0-or-later /* * 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. */ #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 asynchronous transfer requests from all nodes for now */ reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000); /* Specify asynchronous 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);