diff options
Diffstat (limited to 'drivers/misc/ioc4.c')
| -rw-r--r-- | drivers/misc/ioc4.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/drivers/misc/ioc4.c b/drivers/misc/ioc4.c new file mode 100644 index 000000000..ec0832278 --- /dev/null +++ b/drivers/misc/ioc4.c @@ -0,0 +1,500 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005-2006 Silicon Graphics, Inc. All Rights Reserved. + */ + +/* This file contains the master driver module for use by SGI IOC4 subdrivers. + * + * It allocates any resources shared between multiple subdevices, and + * provides accessor functions (where needed) and the like for those + * resources. It also provides a mechanism for the subdevice modules + * to support loading and unloading. + * + * Non-shared resources (e.g. external interrupt A_INT_OUT register page + * alias, serial port and UART registers) are handled by the subdevice + * modules themselves. + * + * This is all necessary because IOC4 is not implemented as a multi-function + * PCI device, but an amalgamation of disparate registers for several + * types of device (ATA, serial, external interrupts). The normal + * resource management in the kernel doesn't have quite the right interfaces + * to handle this situation (e.g. multiple modules can't claim the same + * PCI ID), thus this IOC4 master module. + */ + +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/ioc4.h> +#include <linux/ktime.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/time.h> +#include <asm/io.h> + +/*************** + * Definitions * + ***************/ + +/* Tweakable values */ + +/* PCI bus speed detection/calibration */ +#define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */ +#define IOC4_CALIBRATE_CYCLES 256 /* Average over this many cycles */ +#define IOC4_CALIBRATE_DISCARD 2 /* Discard first few cycles */ +#define IOC4_CALIBRATE_LOW_MHZ 25 /* Lower bound on bus speed sanity */ +#define IOC4_CALIBRATE_HIGH_MHZ 75 /* Upper bound on bus speed sanity */ +#define IOC4_CALIBRATE_DEFAULT_MHZ 66 /* Assumed if sanity check fails */ + +/************************ + * Submodule management * + ************************/ + +static DEFINE_MUTEX(ioc4_mutex); + +static LIST_HEAD(ioc4_devices); +static LIST_HEAD(ioc4_submodules); + +/* Register an IOC4 submodule */ +int +ioc4_register_submodule(struct ioc4_submodule *is) +{ + struct ioc4_driver_data *idd; + + mutex_lock(&ioc4_mutex); + list_add(&is->is_list, &ioc4_submodules); + + /* Initialize submodule for each IOC4 */ + if (!is->is_probe) + goto out; + + list_for_each_entry(idd, &ioc4_devices, idd_list) { + if (is->is_probe(idd)) { + printk(KERN_WARNING + "%s: IOC4 submodule %s probe failed " + "for pci_dev %s", + __func__, module_name(is->is_owner), + pci_name(idd->idd_pdev)); + } + } + out: + mutex_unlock(&ioc4_mutex); + return 0; +} + +/* Unregister an IOC4 submodule */ +void +ioc4_unregister_submodule(struct ioc4_submodule *is) +{ + struct ioc4_driver_data *idd; + + mutex_lock(&ioc4_mutex); + list_del(&is->is_list); + + /* Remove submodule for each IOC4 */ + if (!is->is_remove) + goto out; + + list_for_each_entry(idd, &ioc4_devices, idd_list) { + if (is->is_remove(idd)) { + printk(KERN_WARNING + "%s: IOC4 submodule %s remove failed " + "for pci_dev %s.\n", + __func__, module_name(is->is_owner), + pci_name(idd->idd_pdev)); + } + } + out: + mutex_unlock(&ioc4_mutex); +} + +/********************* + * Device management * + *********************/ + +#define IOC4_CALIBRATE_LOW_LIMIT \ + (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_LOW_MHZ) +#define IOC4_CALIBRATE_HIGH_LIMIT \ + (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_HIGH_MHZ) +#define IOC4_CALIBRATE_DEFAULT \ + (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_DEFAULT_MHZ) + +#define IOC4_CALIBRATE_END \ + (IOC4_CALIBRATE_CYCLES + IOC4_CALIBRATE_DISCARD) + +#define IOC4_INT_OUT_MODE_TOGGLE 0x7 /* Toggle INT_OUT every COUNT+1 ticks */ + +/* Determines external interrupt output clock period of the PCI bus an + * IOC4 is attached to. This value can be used to determine the PCI + * bus speed. + * + * IOC4 has a design feature that various internal timers are derived from + * the PCI bus clock. This causes IOC4 device drivers to need to take the + * bus speed into account when setting various register values (e.g. INT_OUT + * register COUNT field, UART divisors, etc). Since this information is + * needed by several subdrivers, it is determined by the main IOC4 driver, + * even though the following code utilizes external interrupt registers + * to perform the speed calculation. + */ +static void +ioc4_clock_calibrate(struct ioc4_driver_data *idd) +{ + union ioc4_int_out int_out; + union ioc4_gpcr gpcr; + unsigned int state, last_state; + uint64_t start, end, period; + unsigned int count; + + /* Enable output */ + gpcr.raw = 0; + gpcr.fields.dir = IOC4_GPCR_DIR_0; + gpcr.fields.int_out_en = 1; + writel(gpcr.raw, &idd->idd_misc_regs->gpcr_s.raw); + + /* Reset to power-on state */ + writel(0, &idd->idd_misc_regs->int_out.raw); + mmiowb(); + + /* Set up square wave */ + int_out.raw = 0; + int_out.fields.count = IOC4_CALIBRATE_COUNT; + int_out.fields.mode = IOC4_INT_OUT_MODE_TOGGLE; + int_out.fields.diag = 0; + writel(int_out.raw, &idd->idd_misc_regs->int_out.raw); + mmiowb(); + + /* Check square wave period averaged over some number of cycles */ + start = ktime_get_ns(); + state = 1; /* make sure the first read isn't a rising edge */ + for (count = 0; count <= IOC4_CALIBRATE_END; count++) { + do { /* wait for a rising edge */ + last_state = state; + int_out.raw = readl(&idd->idd_misc_regs->int_out.raw); + state = int_out.fields.int_out; + } while (last_state || !state); + + /* discard the first few cycles */ + if (count == IOC4_CALIBRATE_DISCARD) + start = ktime_get_ns(); + } + end = ktime_get_ns(); + + /* Calculation rearranged to preserve intermediate precision. + * Logically: + * 1. "end - start" gives us the measurement period over all + * the square wave cycles. + * 2. Divide by number of square wave cycles to get the period + * of a square wave cycle. + * 3. Divide by 2*(int_out.fields.count+1), which is the formula + * by which the IOC4 generates the square wave, to get the + * period of an IOC4 INT_OUT count. + */ + period = (end - start) / + (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1)); + + /* Bounds check the result. */ + if (period > IOC4_CALIBRATE_LOW_LIMIT || + period < IOC4_CALIBRATE_HIGH_LIMIT) { + printk(KERN_INFO + "IOC4 %s: Clock calibration failed. Assuming" + "PCI clock is %d ns.\n", + pci_name(idd->idd_pdev), + IOC4_CALIBRATE_DEFAULT / IOC4_EXTINT_COUNT_DIVISOR); + period = IOC4_CALIBRATE_DEFAULT; + } else { + u64 ns = period; + + do_div(ns, IOC4_EXTINT_COUNT_DIVISOR); + printk(KERN_DEBUG + "IOC4 %s: PCI clock is %llu ns.\n", + pci_name(idd->idd_pdev), (unsigned long long)ns); + } + + /* Remember results. We store the extint clock period rather + * than the PCI clock period so that greater precision is + * retained. Divide by IOC4_EXTINT_COUNT_DIVISOR to get + * PCI clock period. + */ + idd->count_period = period; +} + +/* There are three variants of IOC4 cards: IO9, IO10, and PCI-RT. + * Each brings out different combinations of IOC4 signals, thus. + * the IOC4 subdrivers need to know to which we're attached. + * + * We look for the presence of a SCSI (IO9) or SATA (IO10) controller + * on the same PCI bus at slot number 3 to differentiate IO9 from IO10. + * If neither is present, it's a PCI-RT. + */ +static unsigned int +ioc4_variant(struct ioc4_driver_data *idd) +{ + struct pci_dev *pdev = NULL; + int found = 0; + + /* IO9: Look for a QLogic ISP 12160 at the same bus and slot 3. */ + do { + pdev = pci_get_device(PCI_VENDOR_ID_QLOGIC, + PCI_DEVICE_ID_QLOGIC_ISP12160, pdev); + if (pdev && + idd->idd_pdev->bus->number == pdev->bus->number && + 3 == PCI_SLOT(pdev->devfn)) + found = 1; + } while (pdev && !found); + if (NULL != pdev) { + pci_dev_put(pdev); + return IOC4_VARIANT_IO9; + } + + /* IO10: Look for a Vitesse VSC 7174 at the same bus and slot 3. */ + pdev = NULL; + do { + pdev = pci_get_device(PCI_VENDOR_ID_VITESSE, + PCI_DEVICE_ID_VITESSE_VSC7174, pdev); + if (pdev && + idd->idd_pdev->bus->number == pdev->bus->number && + 3 == PCI_SLOT(pdev->devfn)) + found = 1; + } while (pdev && !found); + if (NULL != pdev) { + pci_dev_put(pdev); + return IOC4_VARIANT_IO10; + } + + /* PCI-RT: No SCSI/SATA controller will be present */ + return IOC4_VARIANT_PCI_RT; +} + +static void +ioc4_load_modules(struct work_struct *work) +{ + request_module("sgiioc4"); +} + +static DECLARE_WORK(ioc4_load_modules_work, ioc4_load_modules); + +/* Adds a new instance of an IOC4 card */ +static int +ioc4_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id) +{ + struct ioc4_driver_data *idd; + struct ioc4_submodule *is; + uint32_t pcmd; + int ret; + + /* Enable IOC4 and take ownership of it */ + if ((ret = pci_enable_device(pdev))) { + printk(KERN_WARNING + "%s: Failed to enable IOC4 device for pci_dev %s.\n", + __func__, pci_name(pdev)); + goto out; + } + pci_set_master(pdev); + + /* Set up per-IOC4 data */ + idd = kmalloc(sizeof(struct ioc4_driver_data), GFP_KERNEL); + if (!idd) { + printk(KERN_WARNING + "%s: Failed to allocate IOC4 data for pci_dev %s.\n", + __func__, pci_name(pdev)); + ret = -ENODEV; + goto out_idd; + } + idd->idd_pdev = pdev; + idd->idd_pci_id = pci_id; + + /* Map IOC4 misc registers. These are shared between subdevices + * so the main IOC4 module manages them. + */ + idd->idd_bar0 = pci_resource_start(idd->idd_pdev, 0); + if (!idd->idd_bar0) { + printk(KERN_WARNING + "%s: Unable to find IOC4 misc resource " + "for pci_dev %s.\n", + __func__, pci_name(idd->idd_pdev)); + ret = -ENODEV; + goto out_pci; + } + if (!request_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs), + "ioc4_misc")) { + printk(KERN_WARNING + "%s: Unable to request IOC4 misc region " + "for pci_dev %s.\n", + __func__, pci_name(idd->idd_pdev)); + ret = -ENODEV; + goto out_pci; + } + idd->idd_misc_regs = ioremap(idd->idd_bar0, + sizeof(struct ioc4_misc_regs)); + if (!idd->idd_misc_regs) { + printk(KERN_WARNING + "%s: Unable to remap IOC4 misc region " + "for pci_dev %s.\n", + __func__, pci_name(idd->idd_pdev)); + ret = -ENODEV; + goto out_misc_region; + } + + /* Failsafe portion of per-IOC4 initialization */ + + /* Detect card variant */ + idd->idd_variant = ioc4_variant(idd); + printk(KERN_INFO "IOC4 %s: %s card detected.\n", pci_name(pdev), + idd->idd_variant == IOC4_VARIANT_IO9 ? "IO9" : + idd->idd_variant == IOC4_VARIANT_PCI_RT ? "PCI-RT" : + idd->idd_variant == IOC4_VARIANT_IO10 ? "IO10" : "unknown"); + + /* Initialize IOC4 */ + pci_read_config_dword(idd->idd_pdev, PCI_COMMAND, &pcmd); + pci_write_config_dword(idd->idd_pdev, PCI_COMMAND, + pcmd | PCI_COMMAND_PARITY | PCI_COMMAND_SERR); + + /* Determine PCI clock */ + ioc4_clock_calibrate(idd); + + /* Disable/clear all interrupts. Need to do this here lest + * one submodule request the shared IOC4 IRQ, but interrupt + * is generated by a different subdevice. + */ + /* Disable */ + writel(~0, &idd->idd_misc_regs->other_iec.raw); + writel(~0, &idd->idd_misc_regs->sio_iec); + /* Clear (i.e. acknowledge) */ + writel(~0, &idd->idd_misc_regs->other_ir.raw); + writel(~0, &idd->idd_misc_regs->sio_ir); + + /* Track PCI-device specific data */ + idd->idd_serial_data = NULL; + pci_set_drvdata(idd->idd_pdev, idd); + + mutex_lock(&ioc4_mutex); + list_add_tail(&idd->idd_list, &ioc4_devices); + + /* Add this IOC4 to all submodules */ + list_for_each_entry(is, &ioc4_submodules, is_list) { + if (is->is_probe && is->is_probe(idd)) { + printk(KERN_WARNING + "%s: IOC4 submodule 0x%s probe failed " + "for pci_dev %s.\n", + __func__, module_name(is->is_owner), + pci_name(idd->idd_pdev)); + } + } + mutex_unlock(&ioc4_mutex); + + /* Request sgiioc4 IDE driver on boards that bring that functionality + * off of IOC4. The root filesystem may be hosted on a drive connected + * to IOC4, so we need to make sure the sgiioc4 driver is loaded as it + * won't be picked up by modprobes due to the ioc4 module owning the + * PCI device. + */ + if (idd->idd_variant != IOC4_VARIANT_PCI_RT) { + /* Request the module from a work procedure as the modprobe + * goes out to a userland helper and that will hang if done + * directly from ioc4_probe(). + */ + printk(KERN_INFO "IOC4 loading sgiioc4 submodule\n"); + schedule_work(&ioc4_load_modules_work); + } + + return 0; + +out_misc_region: + release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs)); +out_pci: + kfree(idd); +out_idd: + pci_disable_device(pdev); +out: + return ret; +} + +/* Removes a particular instance of an IOC4 card. */ +static void +ioc4_remove(struct pci_dev *pdev) +{ + struct ioc4_submodule *is; + struct ioc4_driver_data *idd; + + idd = pci_get_drvdata(pdev); + + /* Remove this IOC4 from all submodules */ + mutex_lock(&ioc4_mutex); + list_for_each_entry(is, &ioc4_submodules, is_list) { + if (is->is_remove && is->is_remove(idd)) { + printk(KERN_WARNING + "%s: IOC4 submodule 0x%s remove failed " + "for pci_dev %s.\n", + __func__, module_name(is->is_owner), + pci_name(idd->idd_pdev)); + } + } + mutex_unlock(&ioc4_mutex); + + /* Release resources */ + iounmap(idd->idd_misc_regs); + if (!idd->idd_bar0) { + printk(KERN_WARNING + "%s: Unable to get IOC4 misc mapping for pci_dev %s. " + "Device removal may be incomplete.\n", + __func__, pci_name(idd->idd_pdev)); + } + release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs)); + + /* Disable IOC4 and relinquish */ + pci_disable_device(pdev); + + /* Remove and free driver data */ + mutex_lock(&ioc4_mutex); + list_del(&idd->idd_list); + mutex_unlock(&ioc4_mutex); + kfree(idd); +} + +static const struct pci_device_id ioc4_id_table[] = { + {PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC4, PCI_ANY_ID, + PCI_ANY_ID, 0x0b4000, 0xFFFFFF}, + {0} +}; + +static struct pci_driver ioc4_driver = { + .name = "IOC4", + .id_table = ioc4_id_table, + .probe = ioc4_probe, + .remove = ioc4_remove, +}; + +MODULE_DEVICE_TABLE(pci, ioc4_id_table); + +/********************* + * Module management * + *********************/ + +/* Module load */ +static int __init +ioc4_init(void) +{ + return pci_register_driver(&ioc4_driver); +} + +/* Module unload */ +static void __exit +ioc4_exit(void) +{ + /* Ensure ioc4_load_modules() has completed before exiting */ + flush_work(&ioc4_load_modules_work); + pci_unregister_driver(&ioc4_driver); +} + +module_init(ioc4_init); +module_exit(ioc4_exit); + +MODULE_AUTHOR("Brent Casavant - Silicon Graphics, Inc. <bcasavan@sgi.com>"); +MODULE_DESCRIPTION("PCI driver master module for SGI IOC4 Base-IO Card"); +MODULE_LICENSE("GPL"); + +EXPORT_SYMBOL(ioc4_register_submodule); +EXPORT_SYMBOL(ioc4_unregister_submodule); |