1 files changed, 390 insertions, 28 deletions

diff --git a/drivers/sn/ioc4.c b/drivers/sn/ioc4.c
index d9e4ee280e5f..ea75b3d0612b 100644
--- a/drivers/sn/ioc4.c
+++ b/drivers/sn/ioc4.c
@@ -6,60 +6,422 @@
  * Copyright (C) 2005 Silicon Graphics, Inc.  All Rights Reserved.
  */
 
-/*
- * This file contains a shim driver for the IOC4 IDE and serial drivers.
+/* 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_common.h>
-#include <linux/ide.h>
+#include <linux/ioc4.h>
+#include <linux/mmtimer.h>
+#include <linux/rtc.h>
+#include <linux/rwsem.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/clksupport.h>
+#include <asm/sn/shub_mmr.h>
 
+/***************
+ * Definitions *
+ ***************/
 
-static int __devinit
-ioc4_probe_one(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+/* 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 LIST_HEAD(ioc4_devices);
+static DECLARE_RWSEM(ioc4_devices_rwsem);
+
+static LIST_HEAD(ioc4_submodules);
+static DECLARE_RWSEM(ioc4_submodules_rwsem);
+
+/* Register an IOC4 submodule */
+int
+ioc4_register_submodule(struct ioc4_submodule *is)
+{
+        struct ioc4_driver_data *idd;
+
+        down_write(&ioc4_submodules_rwsem);
+        list_add(&is->is_list, &ioc4_submodules);
+        up_write(&ioc4_submodules_rwsem);
+
+        /* Initialize submodule for each IOC4 */
+        if (!is->is_probe)
+                return 0;
+
+        down_read(&ioc4_devices_rwsem);
+        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",
+                               __FUNCTION__, module_name(is->is_owner),
+                               pci_name(idd->idd_pdev));
+                }
+        }
+        up_read(&ioc4_devices_rwsem);
+
+        return 0;
+}
+
+/* Unregister an IOC4 submodule */
+void
+ioc4_unregister_submodule(struct ioc4_submodule *is)
+{
+        struct ioc4_driver_data *idd;
+
+        down_write(&ioc4_submodules_rwsem);
+        list_del(&is->is_list);
+        up_write(&ioc4_submodules_rwsem);
+
+        /* Remove submodule for each IOC4 */
+        if (!is->is_remove)
+                return;
+
+        down_read(&ioc4_devices_rwsem);
+        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",
+                               __FUNCTION__, module_name(is->is_owner),
+                               pci_name(idd->idd_pdev));
+                }
+        }
+        up_read(&ioc4_devices_rwsem);
+}
+
+/*********************
+ * 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)
+{
+        extern unsigned long sn_rtc_cycles_per_second;
+        union ioc4_int_out int_out;
+        union ioc4_gpcr gpcr;
+        unsigned int state, last_state = 1;
+        uint64_t start = 0, 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();
+
+        printk(KERN_INFO
+               "%s: Calibrating PCI bus speed "
+               "for pci_dev %s ... ", __FUNCTION__, pci_name(idd->idd_pdev));
+        /* 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) {
+                                end = rtc_time();
+                                break;
+                        } else if (count == IOC4_CALIBRATE_DISCARD)
+                                start = rtc_time();
+                }
+                last_state = state;
+        } while (1);
+
+        /* Calculation rearranged to preserve intermediate precision.
+         * Logically:
+         * 1. "end - start" gives us number of RTC cycles over all the
+         *    square wave cycles measured.
+         * 2. Divide by number of square wave cycles to get number of
+         *    RTC cycles per 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
+         *    number of RTC cycles per IOC4 INT_OUT count.
+         * 4. Divide by sn_rtc_cycles_per_second to get seconds per
+         *    count.
+         * 5. Multiply by 1E9 to get nanoseconds per count.
+         */
+        period = ((end - start) * 1000000000) /
+            (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1)
+             * sn_rtc_cycles_per_second);
+
+        /* Bounds check the result. */
+        if (period > IOC4_CALIBRATE_LOW_LIMIT ||
+            period < IOC4_CALIBRATE_HIGH_LIMIT) {
+                printk("failed. Assuming PCI clock ticks are %d ns.\n",
+                       IOC4_CALIBRATE_DEFAULT / IOC4_EXTINT_COUNT_DIVISOR);
+                period = IOC4_CALIBRATE_DEFAULT;
+        } else {
+                printk("succeeded. PCI clock ticks are %ld ns.\n",
+                       period / IOC4_EXTINT_COUNT_DIVISOR);
+        }
+
+        /* 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;
+}
+
+/* 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 device with "
-                                "pci_dev 0x%p... returning\n",
-                                __FUNCTION__, (void *)pdev);
-                return ret;
+                       "%s: Failed to enable IOC4 device for pci_dev %s.\n",
+                       __FUNCTION__, pci_name(pdev));
+                goto out;
         }
         pci_set_master(pdev);
 
-        /* attach each sub-device */
-        ret = ioc4_ide_attach_one(pdev, pci_id);
-        if (ret)
-                return ret;
-        return ioc4_serial_attach_one(pdev, pci_id);
+        /* 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",
+                       __FUNCTION__, 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",
+                       __FUNCTION__, pci_name(idd->idd_pdev));
+                ret = -ENODEV;
+                goto out_pci;
+        }
+        if (!request_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",
+                       __FUNCTION__, 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",
+                       __FUNCTION__, pci_name(idd->idd_pdev));
+                ret = -ENODEV;
+                goto out_misc_region;
+        }
+
+        /* Failsafe portion of per-IOC4 initialization */
+
+        /* 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);
+        down_write(&ioc4_devices_rwsem);
+        list_add(&idd->idd_list, &ioc4_devices);
+        up_write(&ioc4_devices_rwsem);
+
+        /* Add this IOC4 to all submodules */
+        down_read(&ioc4_submodules_rwsem);
+        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",
+                               __FUNCTION__, module_name(is->is_owner),
+                               pci_name(idd->idd_pdev));
+                }
+        }
+        up_read(&ioc4_submodules_rwsem);
+
+        return 0;
+
+out_misc_region:
+        release_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
+out_pci:
+        kfree(idd);
+out_idd:
+        pci_disable_device(pdev);
+out:
+        return ret;
 }
 
-/* pci device struct */
-static struct pci_device_id ioc4_s_id_table[] = {
+/* 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 */
+        down_read(&ioc4_submodules_rwsem);
+        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",
+                               __FUNCTION__, module_name(is->is_owner),
+                               pci_name(idd->idd_pdev));
+                }
+        }
+        up_read(&ioc4_submodules_rwsem);
+
+        /* 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",
+                       __FUNCTION__, pci_name(idd->idd_pdev));
+        }
+        release_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
+
+        /* Disable IOC4 and relinquish */
+        pci_disable_device(pdev);
+
+        /* Remove and free driver data */
+        down_write(&ioc4_devices_rwsem);
+        list_del(&idd->idd_list);
+        up_write(&ioc4_devices_rwsem);
+        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}
 };
-MODULE_DEVICE_TABLE(pci, ioc4_s_id_table);
 
-static struct pci_driver __devinitdata ioc4_s_driver = {
-        .name   = "IOC4",
-        .id_table = ioc4_s_id_table,
-        .probe  = ioc4_probe_one,
+static struct pci_driver __devinitdata ioc4_driver = {
+        .name = "IOC4",
+        .id_table = ioc4_id_table,
+        .probe = ioc4_probe,
+        .remove = ioc4_remove,
 };
 
-static int __devinit ioc4_detect(void)
+MODULE_DEVICE_TABLE(pci, ioc4_id_table);
+
+/*********************
+ * Module management *
+ *********************/
+
+/* Module load */
+static int __devinit
+ioc4_init(void)
 {
-        ioc4_serial_init();
+        return pci_register_driver(&ioc4_driver);
+}
 
-        return pci_register_driver(&ioc4_s_driver);
+/* Module unload */
+static void __devexit
+ioc4_exit(void)
+{
+        pci_unregister_driver(&ioc4_driver);
 }
-module_init(ioc4_detect);
 
-MODULE_AUTHOR("Pat Gefre - Silicon Graphics Inc. (SGI) <pfg@sgi.com>");
-MODULE_DESCRIPTION("PCI driver module for SGI IOC4 Base-IO Card");
+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);