cpqphp_ctrl.c

底层驱动开发

/*
 * Compaq Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman ([e-mail])
 * 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.
 *
 * Send feedback to <[e-mail]>
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/smp_lock.h>
#include <linux/pci.h>
#include "cpqphp.h"

static u32 configure_new_device(struct controller* ctrl, struct pci_func *func,
			u8 behind_bridge, struct resource_lists *resources);
static int configure_new_function(struct controller* ctrl, struct pci_func *func,
			u8 behind_bridge, struct resource_lists *resources);
static void interrupt_event_handler(struct controller *ctrl);

static struct semaphore event_semaphore;	/* mutex for process loop (up if something to process) */
static struct semaphore event_exit;		/* guard ensure thread has exited before calling it quits */
static int event_finished;
static unsigned long pushbutton_pending;	/* = 0 */

/* things needed for the long_delay function */
static struct semaphore		delay_sem;
static wait_queue_head_t	delay_wait;

/* delay is in jiffies to wait for */
static void long_delay(int delay)
{
	DECLARE_WAITQUEUE(wait, current);
	
	/* only allow 1 customer into the delay queue at once
	 * yes this makes some people wait even longer, but who really cares?
	 * this is for _huge_ delays to make the hardware happy as the 
	 * signals bounce around
	 */
	down (&delay_sem);

	init_waitqueue_head(&delay_wait);

	add_wait_queue(&delay_wait, &wait);
	msleep_interruptible(jiffies_to_msecs(delay));
	remove_wait_queue(&delay_wait, &wait);
	
	up(&delay_sem);
}


/* FIXME: The following line needs to be somewhere else... */
#define WRONG_BUS_FREQUENCY 0x07
static u8 handle_switch_change(u8 change, struct controller * ctrl)
{
	int hp_slot;
	u8 rc = 0;
	u16 temp_word;
	struct pci_func *func;
	struct event_info *taskInfo;

	if (!change)
		return 0;

	/* Switch Change */
	dbg("cpqsbd:  Switch interrupt received.\n");

	for (hp_slot = 0; hp_slot < 6; hp_slot++) {
		if (change & (0x1L << hp_slot)) {
			/**********************************
			 * this one changed.
			 **********************************/
			func = cpqhp_slot_find(ctrl->bus,
				(hp_slot + ctrl->slot_device_offset), 0);

			/* this is the structure that tells the worker thread
			 *what to do */
			taskInfo = &(ctrl->event_queue[ctrl->next_event]);
			ctrl->next_event = (ctrl->next_event + 1) % 10;
			taskInfo->hp_slot = hp_slot;

			rc++;

			temp_word = ctrl->ctrl_int_comp >> 16;
			func->presence_save = (temp_word >> hp_slot) & 0x01;
			func->presence_save |= (temp_word >> (hp_slot + 7)) & 0x02;

			if (ctrl->ctrl_int_comp & (0x1L << hp_slot)) {
				/**********************************
				 * Switch opened
				 **********************************/

				func->switch_save = 0;

				taskInfo->event_type = INT_SWITCH_OPEN;
			} else {
				/**********************************
				 * Switch closed
				 **********************************/

				func->switch_save = 0x10;

				taskInfo->event_type = INT_SWITCH_CLOSE;
			}
		}
	}

	return rc;
}

/**
 * cpqhp_find_slot: find the struct slot of given device
 * @ctrl: scan lots of this controller
 * @device: the device id to find
 */
static struct slot *cpqhp_find_slot(struct controller *ctrl, u8 device)
{
	struct slot *slot = ctrl->slot;

	while (slot && (slot->device != device)) {
		slot = slot->next;
	}

	return slot;
}


static u8 handle_presence_change(u16 change, struct controller * ctrl)
{
	int hp_slot;
	u8 rc = 0;
	u8 temp_byte;
	u16 temp_word;
	struct pci_func *func;
	struct event_info *taskInfo;
	struct slot *p_slot;

	if (!change)
		return 0;

	/**********************************
	 * Presence Change
	 **********************************/
	dbg("cpqsbd:  Presence/Notify input change.\n");
	dbg("         Changed bits are 0x%4.4x\n", change );

	for (hp_slot = 0; hp_slot < 6; hp_slot++) {
		if (change & (0x0101 << hp_slot)) {
			/**********************************
			 * this one changed.
			 **********************************/
			func = cpqhp_slot_find(ctrl->bus,
				(hp_slot + ctrl->slot_device_offset), 0);

			taskInfo = &(ctrl->event_queue[ctrl->next_event]);
			ctrl->next_event = (ctrl->next_event + 1) % 10;
			taskInfo->hp_slot = hp_slot;

			rc++;

			p_slot = cpqhp_find_slot(ctrl, hp_slot + (readb(ctrl->hpc_reg + SLOT_MASK) >> 4));
			if (!p_slot)
				return 0;

			/* If the switch closed, must be a button
			 * If not in button mode, nevermind */
			if (func->switch_save && (ctrl->push_button == 1)) {
				temp_word = ctrl->ctrl_int_comp >> 16;
				temp_byte = (temp_word >> hp_slot) & 0x01;
				temp_byte |= (temp_word >> (hp_slot + 7)) & 0x02;

				if (temp_byte != func->presence_save) {
					/**************************************
					 * button Pressed (doesn't do anything)
					 **************************************/
					dbg("hp_slot %d button pressed\n", hp_slot);
					taskInfo->event_type = INT_BUTTON_PRESS;
				} else {
					/**********************************
					 * button Released - TAKE ACTION!!!!
					 **********************************/
					dbg("hp_slot %d button released\n", hp_slot);
					taskInfo->event_type = INT_BUTTON_RELEASE;

					/* Cancel if we are still blinking */
					if ((p_slot->state == BLINKINGON_STATE)
					    || (p_slot->state == BLINKINGOFF_STATE)) {
						taskInfo->event_type = INT_BUTTON_CANCEL;
						dbg("hp_slot %d button cancel\n", hp_slot);
					} else if ((p_slot->state == POWERON_STATE)
						   || (p_slot->state == POWEROFF_STATE)) {
						/* info(msg_button_ignore, p_slot->number); */
						taskInfo->event_type = INT_BUTTON_IGNORE;
						dbg("hp_slot %d button ignore\n", hp_slot);
					}
				}
			} else {
				/* Switch is open, assume a presence change
				 * Save the presence state */
				temp_word = ctrl->ctrl_int_comp >> 16;
				func->presence_save = (temp_word >> hp_slot) & 0x01;
				func->presence_save |= (temp_word >> (hp_slot + 7)) & 0x02;

				if ((!(ctrl->ctrl_int_comp & (0x010000 << hp_slot))) ||
				    (!(ctrl->ctrl_int_comp & (0x01000000 << hp_slot)))) {
					/* Present */
					taskInfo->event_type = INT_PRESENCE_ON;
				} else {
					/* Not Present */
					taskInfo->event_type = INT_PRESENCE_OFF;
				}
			}
		}
	}

	return rc;
}


static u8 handle_power_fault(u8 change, struct controller * ctrl)
{
	int hp_slot;
	u8 rc = 0;
	struct pci_func *func;
	struct event_info *taskInfo;

	if (!change)
		return 0;

	/**********************************
	 * power fault
	 **********************************/

	info("power fault interrupt\n");

	for (hp_slot = 0; hp_slot < 6; hp_slot++) {
		if (change & (0x01 << hp_slot)) {
			/**********************************
			 * this one changed.
			 **********************************/
			func = cpqhp_slot_find(ctrl->bus,
				(hp_slot + ctrl->slot_device_offset), 0);

			taskInfo = &(ctrl->event_queue[ctrl->next_event]);
			ctrl->next_event = (ctrl->next_event + 1) % 10;
			taskInfo->hp_slot = hp_slot;

			rc++;

			if (ctrl->ctrl_int_comp & (0x00000100 << hp_slot)) {
				/**********************************
				 * power fault Cleared
				 **********************************/
				func->status = 0x00;

				taskInfo->event_type = INT_POWER_FAULT_CLEAR;
			} else {
				/**********************************
				 * power fault
				 **********************************/
				taskInfo->event_type = INT_POWER_FAULT;

				if (ctrl->rev < 4) {
					amber_LED_on (ctrl, hp_slot);
					green_LED_off (ctrl, hp_slot);
					set_SOGO (ctrl);

					/* this is a fatal condition, we want
					 * to crash the machine to protect from
					 * data corruption. simulated_NMI
					 * shouldn't ever return */
					/* FIXME
					simulated_NMI(hp_slot, ctrl); */

					/* The following code causes a software
					 * crash just in case simulated_NMI did
					 * return */
					/*FIXME
					panic(msg_power_fault); */
				} else {
					/* set power fault status for this board */
					func->status = 0xFF;
					info("power fault bit %x set\n", hp_slot);
				}
			}
		}
	}

	return rc;
}


/**
 * sort_by_size: sort nodes on the list by their length, smallest first.
 * @head: list to sort
 *
 */
static int sort_by_size(struct pci_resource **head)
{
	struct pci_resource *current_res;
	struct pci_resource *next_res;
	int out_of_order = 1;

	if (!(*head))
		return 1;

	if (!((*head)->next))
		return 0;

	while (out_of_order) {
		out_of_order = 0;

		/* Special case for swapping list head */
		if (((*head)->next) &&
		    ((*head)->length > (*head)->next->length)) {
			out_of_order++;
			current_res = *head;
			*head = (*head)->next;
			current_res->next = (*head)->next;
			(*head)->next = current_res;
		}

		current_res = *head;

		while (current_res->next && current_res->next->next) {
			if (current_res->next->length > current_res->next->next->length) {
				out_of_order++;
				next_res = current_res->next;
				current_res->next = current_res->next->next;
				current_res = current_res->next;
				next_res->next = current_res->next;
				current_res->next = next_res;
			} else
				current_res = current_res->next;
		}
	}  /* End of out_of_order loop */

	return 0;
}


/**
 * sort_by_max_size: sort nodes on the list by their length, largest first.
 * @head: list to sort
 *
 */
static int sort_by_max_size(struct pci_resource **head)
{
	struct pci_resource *current_res;
	struct pci_resource *next_res;
	int out_of_order = 1;

	if (!(*head))
		return 1;

	if (!((*head)->next))
		return 0;

	while (out_of_order) {
		out_of_order = 0;

		/* Special case for swapping list head */
		if (((*head)->next) &&
		    ((*head)->length < (*head)->next->length)) {
			out_of_order++;
			current_res = *head;
			*head = (*head)->next;
			current_res->next = (*head)->next;
			(*head)->next = current_res;
		}

		current_res = *head;

		while (current_res->next && current_res->next->next) {
			if (current_res->next->length < current_res->next->next->length) {
				out_of_order++;
				next_res = current_res->next;
				current_res->next = current_res->next->next;
				current_res = current_res->next;
				next_res->next = current_res->next;
				current_res->next = next_res;
			} else
				current_res = current_res->next;
		}
	}  /* End of out_of_order loop */

	return 0;
}


/**
 * do_pre_bridge_resource_split: find node of resources that are unused
 *
 */
static struct pci_resource *do_pre_bridge_resource_split(struct pci_resource **head,
				struct pci_resource **orig_head, u32 alignment)
{
	struct pci_resource *prevnode = NULL;
	struct pci_resource *node;
	struct pci_resource *split_node;
	u32 rc;
	u32 temp_dword;
	dbg("do_pre_bridge_resource_split\n");

	if (!(*head) || !(*orig_head))
		return NULL;

	rc = cpqhp_resource_sort_and_combine(head);

	if (rc)
		return NULL;

	if ((*head)->base != (*orig_head)->base)
		return NULL;

	if ((*head)->length == (*orig_head)->length)
		return NULL;


	/* If we got here, there the bridge requires some of the resource, but
	 * we may be able to split some off of the front */

	node = *head;

	if (node->length & (alignment -1)) {
		/* this one isn't an aligned length, so we'll make a new entry
		 * and split it up. */
		split_node = kmalloc(sizeof(*split_node), GFP_KERNEL);

		if (!split_node)
			return NULL;

		temp_dword = (node->length | (alignment-1)) + 1 - alignment;

		split_node->base = node->base;
		split_node->length = temp_dword;

		node->length -= temp_dword;
		node->base += split_node->length;

		/* Put it in the list */
		*head = split_node;
		split_node->next = node;
	}

	if (node->length < alignment)
		return NULL;

	/* Now unlink it */
	if (*head == node) {
		*head = node->next;
	} else {
		prevnode = *head;
		while (prevnode->next != node)
			prevnode = prevnode->next;

		prevnode->next = node->next;
	}
	node->next = NULL;

	return node;
}


/**
 * do_bridge_resource_split: find one node of resources that aren't in use
 *
 */
static struct pci_resource *do_bridge_resource_split(struct pci_resource **head, u32 alignment)
{
	struct pci_resource *prevnode = NULL;
	struct pci_resource *node;
	u32 rc;
	u32 temp_dword;

	rc = cpqhp_resource_sort_and_combine(head);

	if (rc)
		return NULL;

	node = *head;

	while (node->next) {
		prevnode = node;
		node = node->next;
		kfree(prevnode);
	}

	if (node->length < alignment)
		goto error;

	if (node->base & (alignment - 1)) {
		/* Short circuit if adjusted size is too small */
		temp_dword = (node->base | (alignment-1)) + 1;
		if ((node->length - (temp_dword - node->base)) < alignment)
			goto error;

		node->length -= (temp_dword - node->base);