[PATCH] PCI Hotplug skeleton driver

Greg KH (greg@kroah.com)
Tue, 22 Jan 2002 15:06:39 -0800


Hi,

Here's a patch against 2.5.3-pre3 that adds a PCI Hotplug skeleton
driver which can be used as an example of how to create a PCI Hotplug
driver that works properly with the pci_hotplug core.

thanks,

greg k-h

diff -Nru a/drivers/hotplug/pcihp_skeleton.c b/drivers/hotplug/pcihp_skeleton.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/drivers/hotplug/pcihp_skeleton.c Tue Jan 22 14:53:23 2002
@@ -0,0 +1,432 @@
+/*
+ * PCI Hot Plug Controller Skeleton Driver - 0.1
+ *
+ * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (c) 2001 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT. 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * This driver is to be used as a skeleton driver to be show how to interface
+ * with the pci hotplug core easily.
+ *
+ * Send feedback to <greg@kroah.com>
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include "pci_hotplug.h"
+
+
+#define SLOT_MAGIC 0x67267322
+struct slot {
+ u32 magic;
+ u8 number;
+ struct hotplug_slot *hotplug_slot;
+ struct list_head slot_list;
+};
+
+static LIST_HEAD(slot_list);
+
+#if !defined(CONFIG_HOTPLUG_PCI_SKELETON_MODULE)
+ #define MY_NAME "pcihp_skeleton"
+#else
+ #define MY_NAME THIS_MODULE->name
+#endif
+
+#define dbg(format, arg...) \
+ do { \
+ if (debug) \
+ printk (KERN_DEBUG "%s: " format "\n", \
+ MY_NAME , ## arg); \
+ } while (0)
+#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
+#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
+#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)
+
+
+
+/* local variables */
+static int debug;
+static int num_slots;
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
+#define DRIVER_DESC "Hot Plug PCI Controller Skeleton Driver"
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_PARM(debug, "i");
+MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
+
+static int enable_slot (struct hotplug_slot *slot);
+static int disable_slot (struct hotplug_slot *slot);
+static int set_attention_status (struct hotplug_slot *slot, u8 value);
+static int hardware_test (struct hotplug_slot *slot, u32 value);
+static int get_power_status (struct hotplug_slot *slot, u8 *value);
+static int get_attention_status (struct hotplug_slot *slot, u8 *value);
+static int get_latch_status (struct hotplug_slot *slot, u8 *value);
+static int get_adapter_status (struct hotplug_slot *slot, u8 *value);
+
+static struct hotplug_slot_ops skel_hotplug_slot_ops = {
+ owner: THIS_MODULE,
+ enable_slot: enable_slot,
+ disable_slot: disable_slot,
+ set_attention_status: set_attention_status,
+ hardware_test: hardware_test,
+ get_power_status: get_power_status,
+ get_attention_status: get_attention_status,
+ get_latch_status: get_latch_status,
+ get_adapter_status: get_adapter_status,
+};
+
+
+/* Inline functions to check the sanity of a pointer that is passed to us */
+static inline int slot_paranoia_check (struct slot *slot, const char *function)
+{
+ if (!slot) {
+ dbg("%s - slot == NULL", function);
+ return -1;
+ }
+ if (slot->magic != SLOT_MAGIC) {
+ dbg("%s - bad magic number for slot", function);
+ return -1;
+ }
+ if (!slot->hotplug_slot) {
+ dbg("%s - slot->hotplug_slot == NULL!", function);
+ return -1;
+ }
+ return 0;
+}
+
+static inline struct slot *get_slot (struct hotplug_slot *hotplug_slot, const char *function)
+{
+ struct slot *slot;
+
+ if (!hotplug_slot) {
+ dbg("%s - hotplug_slot == NULL\n", function);
+ return NULL;
+ }
+
+ slot = (struct slot *)hotplug_slot->private;
+ if (slot_paranoia_check (slot, function))
+ return NULL;
+ return slot;
+}
+
+
+static int enable_slot (struct hotplug_slot *hotplug_slot)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg ("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
+
+ /*
+ * Fill in code here to enable the specified slot
+ */
+
+ return retval;
+}
+
+
+static int disable_slot (struct hotplug_slot *hotplug_slot)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg ("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
+
+ /*
+ * Fill in code here to disable the specified slot
+ */
+
+ return retval;
+}
+
+static int set_attention_status (struct hotplug_slot *hotplug_slot, u8 status)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg ("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
+
+ switch (status) {
+ case 0:
+ /*
+ * Fill in code here to turn light off
+ */
+ break;
+
+ case 1:
+ default:
+ /*
+ * Fill in code here to turn light on
+ */
+ break;
+ }
+
+ return retval;
+}
+
+static int hardware_test (struct hotplug_slot *hotplug_slot, u32 value)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg ("%s - physical_slot = %s\n", __FUNCTION__, hotplug_slot->name);
+
+ err ("No hardware tests are defined for this driver");
+ retval = -ENODEV;
+
+ /* Or you can specify a test if you want to */
+
+ return retval;
+}
+
+static int get_power_status (struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg(__FUNCTION__" - physical_slot = %s\n", hotplug_slot->name);
+
+ /*
+ * Fill in logic to get the current power status of the specific
+ * slot and store it in the *value location.
+ */
+
+ return retval;
+}
+
+static int get_attention_status (struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg(__FUNCTION__" - physical_slot = %s\n", hotplug_slot->name);
+
+ /*
+ * Fill in logic to get the current attention status of the specific
+ * slot and store it in the *value location.
+ */
+
+ return retval;
+}
+
+static int get_latch_status (struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg(__FUNCTION__" - physical_slot = %s\n", hotplug_slot->name);
+
+ /*
+ * Fill in logic to get the current latch status of the specific
+ * slot and store it in the *value location.
+ */
+
+ return retval;
+}
+
+static int get_adapter_status (struct hotplug_slot *hotplug_slot, u8 *value)
+{
+ struct slot *slot = get_slot (hotplug_slot, __FUNCTION__);
+ int retval = 0;
+
+ if (slot == NULL)
+ return -ENODEV;
+
+ dbg(__FUNCTION__" - physical_slot = %s\n", hotplug_slot->name);
+
+ /*
+ * Fill in logic to get the current adapter status of the specific
+ * slot and store it in the *value location.
+ */
+
+ return retval;
+}
+
+#define SLOT_NAME_SIZE 10
+static void make_slot_name (struct slot *slot)
+{
+ /*
+ * Stupid way to make a filename out of the slot name.
+ * replace this if your hardware provides a better way to name slots.
+ */
+ snprintf (slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d", slot->number);
+}
+
+static int init_slots (void)
+{
+ struct slot *slot;
+ struct hotplug_slot *hotplug_slot;
+ struct hotplug_slot_info *info;
+ char *name;
+ int retval = 0;
+ int i;
+
+ /*
+ * Create a structure for each slot, and register that slot
+ * with the pci_hotplug subsystem.
+ */
+ for (i = 0; i < num_slots; ++i) {
+ slot = kmalloc (sizeof (struct slot), GFP_KERNEL);
+ if (!slot)
+ return -ENOMEM;
+ memset(slot, 0, sizeof(struct slot));
+
+ hotplug_slot = kmalloc (sizeof (struct hotplug_slot), GFP_KERNEL);
+ if (!hotplug_slot) {
+ kfree (slot);
+ return -ENOMEM;
+ }
+ memset(hotplug_slot, 0, sizeof (struct hotplug_slot));
+ slot->hotplug_slot = hotplug_slot;
+
+ info = kmalloc (sizeof (struct hotplug_slot_info), GFP_KERNEL);
+ if (!info) {
+ kfree (hotplug_slot);
+ kfree (slot);
+ return -ENOMEM;
+ }
+ memset(info, 0, sizeof (struct hotplug_slot_info));
+ hotplug_slot->info = info;
+
+ name = kmalloc (SLOT_NAME_SIZE, GFP_KERNEL);
+ if (!name) {
+ kfree (info);
+ kfree (hotplug_slot);
+ kfree (slot);
+ return -ENOMEM;
+ }
+ hotplug_slot->name = name;
+
+ slot->magic = SLOT_MAGIC;
+ slot->number = i;
+
+ hotplug_slot->private = slot;
+ make_slot_name (slot);
+ hotplug_slot->ops = &skel_hotplug_slot_ops;
+
+ /*
+ * Initilize the slot info structure with some known
+ * good values.
+ */
+ info->power_status = get_skel_power_status(slot);
+ info->attention_status = get_skel_attention_status(slot);
+ info->latch_status = get_skel_latch_status(slot);
+ info->adapter_status = get_skel_adapter_status(slot);
+
+ dbg ("registering slot %d\n", i);
+ retval = pci_hp_register (slot->hotplug_slot);
+ if (retval) {
+ err ("pci_hp_register failed with error %d\n", retval);
+ kfree (info);
+ kfree (name);
+ kfree (hotplug_slot);
+ kfree (slot);
+ return retval;
+ }
+
+ /* add slot to our internal list */
+ list_add (&slot->slot_list, &slot_list);
+ }
+
+ return retval;
+}
+
+static void cleanup_slots (void)
+{
+ struct list_head *tmp;
+ struct slot *slot;
+
+ /*
+ * Unregister all of our slots with the pci_hotplug subsystem,
+ * and free up all memory that we had allocated.
+ */
+ list_for_each (tmp, &slot_list) {
+ slot = list_entry (tmp, struct slot, slot_list);
+ list_del (&slot->slot_list);
+ pci_hp_deregister (slot->hotplug_slot);
+ kfree (slot->hotplug_slot->info);
+ kfree (slot->hotplug_slot->name);
+ kfree (slot->hotplug_slot);
+ kfree (slot);
+ }
+
+ return;
+}
+
+static int __init pcihp_skel_init(void)
+{
+ int retval;
+
+ /*
+ * Do specific initialization stuff for your driver here
+ * Like initilizing your controller hardware (if any) and
+ * determining the number of slots you have in the system
+ * right now.
+ */
+ num_slots = 5;
+
+ retval = init_slots();
+ if (retval)
+ return retval;
+
+ info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
+ return 0;
+}
+
+static void __exit pcihp_skel_exit(void)
+{
+ /*
+ * Clean everything up.
+ */
+ cleanup_slots();
+}
+
+module_init(pcihp_skel_init);
+module_exit(pcihp_skel_exit);
+
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