[linux.git] / drivers / misc / ioc4.c

/*
 * 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/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 __devinit
ioc4_clock_calibrate(struct ioc4_driver_data *idd)
{
	union ioc4_int_out int_out;
	union ioc4_gpcr gpcr;
	unsigned int state, last_state = 1;
	struct timespec start_ts, end_ts;
	uint64_t start, end, period;
	unsigned int count = 0;

	/* 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 */
	do {
		int_out.raw = readl(&idd->idd_misc_regs->int_out.raw);
		state = int_out.fields.int_out;
		if (!last_state && state) {
			count++;
			if (count == IOC4_CALIBRATE_END) {
				ktime_get_ts(&end_ts);
				break;
			} else if (count == IOC4_CALIBRATE_DISCARD)
				ktime_get_ts(&start_ts);
		}
		last_state = state;
	} while (1);

	/* 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.
	 */
	end = end_ts.tv_sec * NSEC_PER_SEC + end_ts.tv_nsec;
	start = start_ts.tv_sec * NSEC_PER_SEC + start_ts.tv_nsec;
	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 __devinit
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 __devinit
ioc4_load_modules(struct work_struct *work)
{
	/* arg just has to be freed */

	request_module("sgiioc4");

	kfree(work);
}

/* Adds a new instance of an IOC4 card */
static int __devinit
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) {
		struct work_struct *work;
		work = kzalloc(sizeof(struct work_struct), GFP_KERNEL);
		if (!work) {
			printk(KERN_WARNING
			       "%s: IOC4 unable to allocate memory for "
			       "load of sub-modules.\n", __func__);
		} else {
			/* 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");
			INIT_WORK(work, ioc4_load_modules);
			schedule_work(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 __devexit
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 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 = __devexit_p(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_scheduled_work();
	pci_unregister_driver(&ioc4_driver);
}

module_init(ioc4_init);
module_exit(ioc4_exit);

MODULE_AUTHOR("Brent Casavant - Silicon Graphics, Inc. <[email protected]>");
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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
107d5a72	6	* Copyright (C) 2005-2006 Silicon Graphics, Inc. All Rights Reserved.
1da177e4 LT	7	*/
1da177e4 LT	8
22329b51 BC	9	/* This file contains the master driver module for use by SGI IOC4 subdrivers.
	10	*
	11	* It allocates any resources shared between multiple subdevices, and
	12	* provides accessor functions (where needed) and the like for those
	13	* resources. It also provides a mechanism for the subdevice modules
	14	* to support loading and unloading.
	15	*
	16	* Non-shared resources (e.g. external interrupt A_INT_OUT register page
	17	* alias, serial port and UART registers) are handled by the subdevice
	18	* modules themselves.
	19	*
	20	* This is all necessary because IOC4 is not implemented as a multi-function
	21	* PCI device, but an amalgamation of disparate registers for several
	22	* types of device (ATA, serial, external interrupts). The normal
	23	* resource management in the kernel doesn't have quite the right interfaces
	24	* to handle this situation (e.g. multiple modules can't claim the same
	25	* PCI ID), thus this IOC4 master module.
1da177e4 LT	26	*/
	27
	28	#include <linux/errno.h>
	29	#include <linux/module.h>
	30	#include <linux/pci.h>
22329b51	31	#include <linux/ioc4.h>
107d5a72	32	#include <linux/ktime.h>
6e586f32	33	#include <linux/mutex.h>
107d5a72	34	#include <linux/time.h>
2099c99e	35	#include <asm/io.h>
d4c477ca BC	36
	37	/***************
	38	* Definitions *
	39	***************/
	40
	41	/* Tweakable values */
	42
	43	/* PCI bus speed detection/calibration */
107d5a72	44	#define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */
d4c477ca BC	45	#define IOC4_CALIBRATE_CYCLES 256 /* Average over this many cycles */
	46	#define IOC4_CALIBRATE_DISCARD 2 /* Discard first few cycles */
	47	#define IOC4_CALIBRATE_LOW_MHZ 25 /* Lower bound on bus speed sanity */
	48	#define IOC4_CALIBRATE_HIGH_MHZ 75 /* Upper bound on bus speed sanity */
	49	#define IOC4_CALIBRATE_DEFAULT_MHZ 66 /* Assumed if sanity check fails */
1da177e4	50
22329b51 BC	51	/************************
	52	* Submodule management *
	53	************************/
1da177e4	54
6e586f32	55	static DEFINE_MUTEX(ioc4_mutex);
22329b51	56
6e586f32	57	static LIST_HEAD(ioc4_devices);
22329b51	58	static LIST_HEAD(ioc4_submodules);
22329b51 BC	59
	60	/* Register an IOC4 submodule */
	61	int
	62	ioc4_register_submodule(struct ioc4_submodule *is)
	63	{
	64	struct ioc4_driver_data *idd;
	65
6e586f32	66	mutex_lock(&ioc4_mutex);
22329b51	67	list_add(&is->is_list, &ioc4_submodules);
22329b51 BC	68
	69	/* Initialize submodule for each IOC4 */
	70	if (!is->is_probe)
6e586f32	71	goto out;
22329b51	72
22329b51 BC	73	list_for_each_entry(idd, &ioc4_devices, idd_list) {
	74	if (is->is_probe(idd)) {
	75	printk(KERN_WARNING
	76	"%s: IOC4 submodule %s probe failed "
	77	"for pci_dev %s",
6e574195	78	__func__, module_name(is->is_owner),
22329b51 BC	79	pci_name(idd->idd_pdev));
	80	}
	81	}
6e586f32 JS	82	out:
6e586f32 JS	83	mutex_unlock(&ioc4_mutex);
22329b51 BC	84	return 0;
	85	}
	86
	87	/* Unregister an IOC4 submodule */
	88	void
	89	ioc4_unregister_submodule(struct ioc4_submodule *is)
1da177e4	90	{
22329b51 BC	91	struct ioc4_driver_data *idd;
22329b51 BC	92
6e586f32	93	mutex_lock(&ioc4_mutex);
22329b51	94	list_del(&is->is_list);
22329b51 BC	95
	96	/* Remove submodule for each IOC4 */
	97	if (!is->is_remove)
6e586f32	98	goto out;
22329b51	99
22329b51 BC	100	list_for_each_entry(idd, &ioc4_devices, idd_list) {
	101	if (is->is_remove(idd)) {
	102	printk(KERN_WARNING
	103	"%s: IOC4 submodule %s remove failed "
	104	"for pci_dev %s.\n",
6e574195	105	__func__, module_name(is->is_owner),
22329b51 BC	106	pci_name(idd->idd_pdev));
	107	}
	108	}
6e586f32 JS	109	out:
6e586f32 JS	110	mutex_unlock(&ioc4_mutex);
22329b51 BC	111	}
	112
	113	/*********************
	114	* Device management *
	115	*********************/
	116
d4c477ca BC	117	#define IOC4_CALIBRATE_LOW_LIMIT \
	118	(1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_LOW_MHZ)
	119	#define IOC4_CALIBRATE_HIGH_LIMIT \
	120	(1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_HIGH_MHZ)
	121	#define IOC4_CALIBRATE_DEFAULT \
	122	(1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_DEFAULT_MHZ)
	123
	124	#define IOC4_CALIBRATE_END \
	125	(IOC4_CALIBRATE_CYCLES + IOC4_CALIBRATE_DISCARD)
	126
	127	#define IOC4_INT_OUT_MODE_TOGGLE 0x7 /* Toggle INT_OUT every COUNT+1 ticks */
	128
	129	/* Determines external interrupt output clock period of the PCI bus an
	130	* IOC4 is attached to. This value can be used to determine the PCI
	131	* bus speed.
	132	*
	133	* IOC4 has a design feature that various internal timers are derived from
	134	* the PCI bus clock. This causes IOC4 device drivers to need to take the
	135	* bus speed into account when setting various register values (e.g. INT_OUT
	136	* register COUNT field, UART divisors, etc). Since this information is
	137	* needed by several subdrivers, it is determined by the main IOC4 driver,
	138	* even though the following code utilizes external interrupt registers
	139	* to perform the speed calculation.
	140	*/
2ea5d35a	141	static void __devinit
d4c477ca BC	142	ioc4_clock_calibrate(struct ioc4_driver_data *idd)
d4c477ca BC	143	{
d4c477ca BC	144	union ioc4_int_out int_out;
	145	union ioc4_gpcr gpcr;
	146	unsigned int state, last_state = 1;
107d5a72 BC	147	struct timespec start_ts, end_ts;
107d5a72 BC	148	uint64_t start, end, period;
d4c477ca BC	149	unsigned int count = 0;
	150
	151	/* Enable output */
	152	gpcr.raw = 0;
	153	gpcr.fields.dir = IOC4_GPCR_DIR_0;
	154	gpcr.fields.int_out_en = 1;
	155	writel(gpcr.raw, &idd->idd_misc_regs->gpcr_s.raw);
	156
	157	/* Reset to power-on state */
	158	writel(0, &idd->idd_misc_regs->int_out.raw);
	159	mmiowb();
	160
d4c477ca BC	161	/* Set up square wave */
	162	int_out.raw = 0;
	163	int_out.fields.count = IOC4_CALIBRATE_COUNT;
	164	int_out.fields.mode = IOC4_INT_OUT_MODE_TOGGLE;
	165	int_out.fields.diag = 0;
	166	writel(int_out.raw, &idd->idd_misc_regs->int_out.raw);
	167	mmiowb();
	168
	169	/* Check square wave period averaged over some number of cycles */
	170	do {
	171	int_out.raw = readl(&idd->idd_misc_regs->int_out.raw);
	172	state = int_out.fields.int_out;
	173	if (!last_state && state) {
	174	count++;
	175	if (count == IOC4_CALIBRATE_END) {
107d5a72	176	ktime_get_ts(&end_ts);
d4c477ca BC	177	break;
d4c477ca BC	178	} else if (count == IOC4_CALIBRATE_DISCARD)
107d5a72	179	ktime_get_ts(&start_ts);
d4c477ca BC	180	}
	181	last_state = state;
	182	} while (1);
	183
	184	/* Calculation rearranged to preserve intermediate precision.
	185	* Logically:
107d5a72 BC	186	* 1. "end - start" gives us the measurement period over all
	187	* the square wave cycles.
	188	* 2. Divide by number of square wave cycles to get the period
	189	* of a square wave cycle.
d4c477ca BC	190	* 3. Divide by 2*(int_out.fields.count+1), which is the formula
d4c477ca BC	191	* by which the IOC4 generates the square wave, to get the
107d5a72	192	* period of an IOC4 INT_OUT count.
d4c477ca	193	*/
107d5a72 BC	194	end = end_ts.tv_sec * NSEC_PER_SEC + end_ts.tv_nsec;
	195	start = start_ts.tv_sec * NSEC_PER_SEC + start_ts.tv_nsec;
	196	period = (end - start) /
	197	(IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1));
d4c477ca BC	198
	199	/* Bounds check the result. */
	200	if (period > IOC4_CALIBRATE_LOW_LIMIT \|\|
	201	period < IOC4_CALIBRATE_HIGH_LIMIT) {
f5befceb BC	202	printk(KERN_INFO
	203	"IOC4 %s: Clock calibration failed. Assuming"
	204	"PCI clock is %d ns.\n",
	205	pci_name(idd->idd_pdev),
d4c477ca BC	206	IOC4_CALIBRATE_DEFAULT / IOC4_EXTINT_COUNT_DIVISOR);
	207	period = IOC4_CALIBRATE_DEFAULT;
	208	} else {
59f14800 BC	209	u64 ns = period;
	210
	211	do_div(ns, IOC4_EXTINT_COUNT_DIVISOR);
f5befceb	212	printk(KERN_DEBUG
760fe9ad RD	213	"IOC4 %s: PCI clock is %llu ns.\n",
760fe9ad RD	214	pci_name(idd->idd_pdev), (unsigned long long)ns);
d4c477ca BC	215	}
	216
	217	/* Remember results. We store the extint clock period rather
	218	* than the PCI clock period so that greater precision is
	219	* retained. Divide by IOC4_EXTINT_COUNT_DIVISOR to get
	220	* PCI clock period.
	221	*/
	222	idd->count_period = period;
	223	}
	224
f5befceb BC	225	/* There are three variants of IOC4 cards: IO9, IO10, and PCI-RT.
	226	* Each brings out different combinations of IOC4 signals, thus.
	227	* the IOC4 subdrivers need to know to which we're attached.
	228	*
	229	* We look for the presence of a SCSI (IO9) or SATA (IO10) controller
	230	* on the same PCI bus at slot number 3 to differentiate IO9 from IO10.
	231	* If neither is present, it's a PCI-RT.
	232	*/
2ea5d35a	233	static unsigned int __devinit
f5befceb BC	234	ioc4_variant(struct ioc4_driver_data *idd)
	235	{
	236	struct pci_dev *pdev = NULL;
	237	int found = 0;
	238
	239	/* IO9: Look for a QLogic ISP 12160 at the same bus and slot 3. */
	240	do {
	241	pdev = pci_get_device(PCI_VENDOR_ID_QLOGIC,
	242	PCI_DEVICE_ID_QLOGIC_ISP12160, pdev);
	243	if (pdev &&
	244	idd->idd_pdev->bus->number == pdev->bus->number &&
	245	3 == PCI_SLOT(pdev->devfn))
	246	found = 1;
f5befceb	247	} while (pdev && !found);
90d8dabf JL	248	if (NULL != pdev) {
90d8dabf JL	249	pci_dev_put(pdev);
f5befceb	250	return IOC4_VARIANT_IO9;
90d8dabf	251	}
f5befceb BC	252
	253	/* IO10: Look for a Vitesse VSC 7174 at the same bus and slot 3. */
	254	pdev = NULL;
	255	do {
	256	pdev = pci_get_device(PCI_VENDOR_ID_VITESSE,
	257	PCI_DEVICE_ID_VITESSE_VSC7174, pdev);
	258	if (pdev &&
	259	idd->idd_pdev->bus->number == pdev->bus->number &&
	260	3 == PCI_SLOT(pdev->devfn))
	261	found = 1;
f5befceb	262	} while (pdev && !found);
90d8dabf JL	263	if (NULL != pdev) {
90d8dabf JL	264	pci_dev_put(pdev);
f5befceb	265	return IOC4_VARIANT_IO10;
90d8dabf	266	}
f5befceb BC	267
	268	/* PCI-RT: No SCSI/SATA controller will be present */
	269	return IOC4_VARIANT_PCI_RT;
	270	}
	271
2ea5d35a	272	static void __devinit
08adefd4 BC	273	ioc4_load_modules(struct work_struct *work)
	274	{
	275	/* arg just has to be freed */
	276
	277	request_module("sgiioc4");
	278
	279	kfree(work);
	280	}
	281
22329b51	282	/* Adds a new instance of an IOC4 card */
2ea5d35a	283	static int __devinit
22329b51 BC	284	ioc4_probe(struct pci_dev pdev, const struct pci_device_id pci_id)
	285	{
	286	struct ioc4_driver_data *idd;
	287	struct ioc4_submodule *is;
	288	uint32_t pcmd;
1da177e4 LT	289	int ret;
1da177e4 LT	290
22329b51	291	/* Enable IOC4 and take ownership of it */
1da177e4 LT	292	if ((ret = pci_enable_device(pdev))) {
1da177e4 LT	293	printk(KERN_WARNING
22329b51	294	"%s: Failed to enable IOC4 device for pci_dev %s.\n",
6e574195	295	__func__, pci_name(pdev));
22329b51	296	goto out;
1da177e4 LT	297	}
	298	pci_set_master(pdev);
	299
22329b51 BC	300	/* Set up per-IOC4 data */
	301	idd = kmalloc(sizeof(struct ioc4_driver_data), GFP_KERNEL);
	302	if (!idd) {
	303	printk(KERN_WARNING
	304	"%s: Failed to allocate IOC4 data for pci_dev %s.\n",
6e574195	305	__func__, pci_name(pdev));
22329b51 BC	306	ret = -ENODEV;
	307	goto out_idd;
	308	}
	309	idd->idd_pdev = pdev;
	310	idd->idd_pci_id = pci_id;
	311
	312	/* Map IOC4 misc registers. These are shared between subdevices
	313	* so the main IOC4 module manages them.
	314	*/
	315	idd->idd_bar0 = pci_resource_start(idd->idd_pdev, 0);
	316	if (!idd->idd_bar0) {
	317	printk(KERN_WARNING
	318	"%s: Unable to find IOC4 misc resource "
	319	"for pci_dev %s.\n",
6e574195	320	__func__, pci_name(idd->idd_pdev));
22329b51 BC	321	ret = -ENODEV;
	322	goto out_pci;
	323	}
52c9ae0a	324	if (!request_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs),
22329b51 BC	325	"ioc4_misc")) {
	326	printk(KERN_WARNING
	327	"%s: Unable to request IOC4 misc region "
	328	"for pci_dev %s.\n",
6e574195	329	__func__, pci_name(idd->idd_pdev));
22329b51 BC	330	ret = -ENODEV;
	331	goto out_pci;
	332	}
	333	idd->idd_misc_regs = ioremap(idd->idd_bar0,
	334	sizeof(struct ioc4_misc_regs));
	335	if (!idd->idd_misc_regs) {
	336	printk(KERN_WARNING
	337	"%s: Unable to remap IOC4 misc region "
	338	"for pci_dev %s.\n",
6e574195	339	__func__, pci_name(idd->idd_pdev));
22329b51 BC	340	ret = -ENODEV;
	341	goto out_misc_region;
	342	}
	343
	344	/* Failsafe portion of per-IOC4 initialization */
	345
f5befceb BC	346	/* Detect card variant */
	347	idd->idd_variant = ioc4_variant(idd);
	348	printk(KERN_INFO "IOC4 %s: %s card detected.\n", pci_name(pdev),
	349	idd->idd_variant == IOC4_VARIANT_IO9 ? "IO9" :
	350	idd->idd_variant == IOC4_VARIANT_PCI_RT ? "PCI-RT" :
	351	idd->idd_variant == IOC4_VARIANT_IO10 ? "IO10" : "unknown");
	352
22329b51 BC	353	/* Initialize IOC4 */
	354	pci_read_config_dword(idd->idd_pdev, PCI_COMMAND, &pcmd);
	355	pci_write_config_dword(idd->idd_pdev, PCI_COMMAND,
	356	pcmd \| PCI_COMMAND_PARITY \| PCI_COMMAND_SERR);
	357
d4c477ca BC	358	/* Determine PCI clock */
	359	ioc4_clock_calibrate(idd);
	360
22329b51 BC	361	/* Disable/clear all interrupts. Need to do this here lest
	362	* one submodule request the shared IOC4 IRQ, but interrupt
	363	* is generated by a different subdevice.
	364	*/
	365	/* Disable */
	366	writel(~0, &idd->idd_misc_regs->other_iec.raw);
	367	writel(~0, &idd->idd_misc_regs->sio_iec);
	368	/* Clear (i.e. acknowledge) */
	369	writel(~0, &idd->idd_misc_regs->other_ir.raw);
	370	writel(~0, &idd->idd_misc_regs->sio_ir);
	371
	372	/* Track PCI-device specific data */
	373	idd->idd_serial_data = NULL;
	374	pci_set_drvdata(idd->idd_pdev, idd);
6e586f32 JS	375
6e586f32 JS	376	mutex_lock(&ioc4_mutex);
8683dc99	377	list_add_tail(&idd->idd_list, &ioc4_devices);
22329b51 BC	378
22329b51 BC	379	/* Add this IOC4 to all submodules */
22329b51 BC	380	list_for_each_entry(is, &ioc4_submodules, is_list) {
	381	if (is->is_probe && is->is_probe(idd)) {
	382	printk(KERN_WARNING
	383	"%s: IOC4 submodule 0x%s probe failed "
	384	"for pci_dev %s.\n",
6e574195	385	__func__, module_name(is->is_owner),
22329b51 BC	386	pci_name(idd->idd_pdev));
	387	}
	388	}
6e586f32	389	mutex_unlock(&ioc4_mutex);
22329b51	390
08adefd4 BC	391	/* Request sgiioc4 IDE driver on boards that bring that functionality
	392	* off of IOC4. The root filesystem may be hosted on a drive connected
	393	* to IOC4, so we need to make sure the sgiioc4 driver is loaded as it
	394	* won't be picked up by modprobes due to the ioc4 module owning the
	395	* PCI device.
	396	*/
	397	if (idd->idd_variant != IOC4_VARIANT_PCI_RT) {
	398	struct work_struct *work;
	399	work = kzalloc(sizeof(struct work_struct), GFP_KERNEL);
	400	if (!work) {
	401	printk(KERN_WARNING
	402	"%s: IOC4 unable to allocate memory for "
	403	"load of sub-modules.\n", __func__);
	404	} else {
	405	/* Request the module from a work procedure as the
	406	* modprobe goes out to a userland helper and that
	407	* will hang if done directly from ioc4_probe().
	408	*/
	409	printk(KERN_INFO "IOC4 loading sgiioc4 submodule\n");
	410	INIT_WORK(work, ioc4_load_modules);
	411	schedule_work(work);
	412	}
	413	}
	414
22329b51 BC	415	return 0;
	416
	417	out_misc_region:
52c9ae0a	418	release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
22329b51 BC	419	out_pci:
	420	kfree(idd);
	421	out_idd:
	422	pci_disable_device(pdev);
	423	out:
	424	return ret;
1da177e4 LT	425	}
1da177e4 LT	426
22329b51	427	/* Removes a particular instance of an IOC4 card. */
2ea5d35a	428	static void __devexit
22329b51 BC	429	ioc4_remove(struct pci_dev *pdev)
	430	{
	431	struct ioc4_submodule *is;
	432	struct ioc4_driver_data *idd;
	433
	434	idd = pci_get_drvdata(pdev);
	435
	436	/* Remove this IOC4 from all submodules */
6e586f32	437	mutex_lock(&ioc4_mutex);
22329b51 BC	438	list_for_each_entry(is, &ioc4_submodules, is_list) {
	439	if (is->is_remove && is->is_remove(idd)) {
	440	printk(KERN_WARNING
	441	"%s: IOC4 submodule 0x%s remove failed "
	442	"for pci_dev %s.\n",
6e574195	443	__func__, module_name(is->is_owner),
22329b51 BC	444	pci_name(idd->idd_pdev));
	445	}
	446	}
6e586f32	447	mutex_unlock(&ioc4_mutex);
22329b51 BC	448
	449	/* Release resources */
	450	iounmap(idd->idd_misc_regs);
	451	if (!idd->idd_bar0) {
	452	printk(KERN_WARNING
	453	"%s: Unable to get IOC4 misc mapping for pci_dev %s. "
	454	"Device removal may be incomplete.\n",
6e574195	455	__func__, pci_name(idd->idd_pdev));
22329b51	456	}
52c9ae0a	457	release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
22329b51 BC	458
	459	/* Disable IOC4 and relinquish */
	460	pci_disable_device(pdev);
	461
	462	/* Remove and free driver data */
6e586f32	463	mutex_lock(&ioc4_mutex);
22329b51	464	list_del(&idd->idd_list);
6e586f32	465	mutex_unlock(&ioc4_mutex);
22329b51 BC	466	kfree(idd);
	467	}
	468
	469	static struct pci_device_id ioc4_id_table[] = {
1da177e4 LT	470	{PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC4, PCI_ANY_ID,
	471	PCI_ANY_ID, 0x0b4000, 0xFFFFFF},
	472	{0}
	473	};
1da177e4	474
85bd8434	475	static struct pci_driver ioc4_driver = {
22329b51 BC	476	.name = "IOC4",
	477	.id_table = ioc4_id_table,
	478	.probe = ioc4_probe,
2ea5d35a	479	.remove = __devexit_p(ioc4_remove),
1da177e4 LT	480	};
1da177e4 LT	481
22329b51 BC	482	MODULE_DEVICE_TABLE(pci, ioc4_id_table);
	483
	484	/*********************
	485	* Module management *
	486	*********************/
	487
	488	/* Module load */
2ea5d35a	489	static int __init
22329b51	490	ioc4_init(void)
1da177e4	491	{
22329b51 BC	492	return pci_register_driver(&ioc4_driver);
22329b51 BC	493	}
1da177e4	494
22329b51	495	/* Module unload */
2ea5d35a	496	static void __exit
22329b51 BC	497	ioc4_exit(void)
22329b51 BC	498	{
08adefd4 BC	499	/* Ensure ioc4_load_modules() has completed before exiting */
08adefd4 BC	500	flush_scheduled_work();
22329b51	501	pci_unregister_driver(&ioc4_driver);
1da177e4	502	}
1da177e4	503
22329b51 BC	504	module_init(ioc4_init);
	505	module_exit(ioc4_exit);
	506
	507	MODULE_AUTHOR("Brent Casavant - Silicon Graphics, Inc. <[email protected]>");
	508	MODULE_DESCRIPTION("PCI driver master module for SGI IOC4 Base-IO Card");
1da177e4	509	MODULE_LICENSE("GPL");
22329b51 BC	510
	511	EXPORT_SYMBOL(ioc4_register_submodule);
	512	EXPORT_SYMBOL(ioc4_unregister_submodule);