maple.c

linux 内核源代码

/*
 * Core maple bus functionality
 *
 *  Copyright (C) 2007 Adrian McMenamin
 *
 * Based on 2.4 code by:
 *
 *  Copyright (C) 2000-2001 YAEGASHI Takeshi
 *  Copyright (C) 2001 M. R. Brown
 *  Copyright (C) 2001 Paul Mundt
 *
 * and others.
 *
 * 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.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/maple.h>
#include <linux/dma-mapping.h>
#include <asm/cacheflush.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/mach/dma.h>
#include <asm/mach/sysasic.h>
#include <asm/mach/maple.h>

MODULE_AUTHOR("Yaegshi Takeshi, Paul Mundt, M.R. Brown, Adrian McMenamin");
MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
MODULE_LICENSE("GPL v2");
MODULE_SUPPORTED_DEVICE("{{SEGA, Dreamcast/Maple}}");

static void maple_dma_handler(struct work_struct *work);
static void maple_vblank_handler(struct work_struct *work);

static DECLARE_WORK(maple_dma_process, maple_dma_handler);
static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);

static LIST_HEAD(maple_waitq);
static LIST_HEAD(maple_sentq);

static DEFINE_MUTEX(maple_list_lock);

static struct maple_driver maple_dummy_driver;
static struct device maple_bus;
static int subdevice_map[MAPLE_PORTS];
static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
static unsigned long maple_pnp_time;
static int started, scanning, liststatus;
static struct kmem_cache *maple_queue_cache;

struct maple_device_specify {
       int port;
       int unit;
};

/**
 *  maple_driver_register - register a device driver
 *  automatically makes the driver bus a maple bus
 *  @drv: the driver to be registered
 */
int maple_driver_register(struct device_driver *drv)
{
       if (!drv)
               return -EINVAL;
       drv->bus = &maple_bus_type;
       return driver_register(drv);
}
EXPORT_SYMBOL_GPL(maple_driver_register);

/* set hardware registers to enable next round of dma */
static void maplebus_dma_reset(void)
{
       ctrl_outl(MAPLE_MAGIC, MAPLE_RESET);
       /* set trig type to 0 for software trigger, 1 for hardware (VBLANK) */
       ctrl_outl(1, MAPLE_TRIGTYPE);
       ctrl_outl(MAPLE_2MBPS | MAPLE_TIMEOUT(50000), MAPLE_SPEED);
       ctrl_outl(PHYSADDR(maple_sendbuf), MAPLE_DMAADDR);
       ctrl_outl(1, MAPLE_ENABLE);
}

/**
 * maple_getcond_callback - setup handling MAPLE_COMMAND_GETCOND
 * @dev: device responding
 * @callback: handler callback
 * @interval: interval in jiffies between callbacks
 * @function: the function code for the device
 */
void maple_getcond_callback(struct maple_device *dev,
                           void (*callback) (struct mapleq * mq),
                           unsigned long interval, unsigned long function)
{
       dev->callback = callback;
       dev->interval = interval;
       dev->function = cpu_to_be32(function);
       dev->when = jiffies;
}
EXPORT_SYMBOL_GPL(maple_getcond_callback);

static int maple_dma_done(void)
{
       return (ctrl_inl(MAPLE_STATE) & 1) == 0;
}

static void maple_release_device(struct device *dev)
{
       if (dev->type) {
               kfree(dev->type->name);
               kfree(dev->type);
       }
}

/**
 * maple_add_packet - add a single instruction to the queue
 * @mq: instruction to add to waiting queue
 */
void maple_add_packet(struct mapleq *mq)
{
       mutex_lock(&maple_list_lock);
       list_add(&mq->list, &maple_waitq);
       mutex_unlock(&maple_list_lock);
}
EXPORT_SYMBOL_GPL(maple_add_packet);

static struct mapleq *maple_allocq(struct maple_device *dev)
{
       struct mapleq *mq;

       mq = kmalloc(sizeof(*mq), GFP_KERNEL);
       if (!mq)
               return NULL;

       mq->dev = dev;
       mq->recvbufdcsp = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
       mq->recvbuf = (void *) P2SEGADDR(mq->recvbufdcsp);
       if (!mq->recvbuf) {
               kfree(mq);
               return NULL;
       }

       return mq;
}

static struct maple_device *maple_alloc_dev(int port, int unit)
{
       struct maple_device *dev;

       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
       if (!dev)
               return NULL;

       dev->port = port;
       dev->unit = unit;
       dev->mq = maple_allocq(dev);

       if (!dev->mq) {
               kfree(dev);
               return NULL;
       }

       return dev;
}

static void maple_free_dev(struct maple_device *mdev)
{
       if (!mdev)
               return;
       if (mdev->mq) {
               kmem_cache_free(maple_queue_cache, mdev->mq->recvbufdcsp);
               kfree(mdev->mq);
       }
       kfree(mdev);
}

/* process the command queue into a maple command block
 * terminating command has bit 32 of first long set to 0
 */
static void maple_build_block(struct mapleq *mq)
{
       int port, unit, from, to, len;
       unsigned long *lsendbuf = mq->sendbuf;

       port = mq->dev->port & 3;
       unit = mq->dev->unit;
       len = mq->length;
       from = port << 6;
       to = (port << 6) | (unit > 0 ? (1 << (unit - 1)) & 0x1f : 0x20);

       *maple_lastptr &= 0x7fffffff;
       maple_lastptr = maple_sendptr;

       *maple_sendptr++ = (port << 16) | len | 0x80000000;
       *maple_sendptr++ = PHYSADDR(mq->recvbuf);
       *maple_sendptr++ =
           mq->command | (to << 8) | (from << 16) | (len << 24);

       while (len-- > 0)
               *maple_sendptr++ = *lsendbuf++;
}

/* build up command queue */
static void maple_send(void)
{
       int i;
       int maple_packets;
       struct mapleq *mq, *nmq;

       if (!list_empty(&maple_sentq))
               return;
       if (list_empty(&maple_waitq) || !maple_dma_done())
               return;
       maple_packets = 0;
       maple_sendptr = maple_lastptr = maple_sendbuf;
       list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
               maple_build_block(mq);
               list_move(&mq->list, &maple_sentq);
               if (maple_packets++ > MAPLE_MAXPACKETS)
                       break;
       }
       if (maple_packets > 0) {
               for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
                       dma_cache_sync(0, maple_sendbuf + i * PAGE_SIZE,
                                      PAGE_SIZE, DMA_BIDIRECTIONAL);
       }
}

static int attach_matching_maple_driver(struct device_driver *driver,
                                       void *devptr)
{
       struct maple_driver *maple_drv;
       struct maple_device *mdev;

       mdev = devptr;
       maple_drv = to_maple_driver(driver);
       if (mdev->devinfo.function & be32_to_cpu(maple_drv->function)) {
               if (maple_drv->connect(mdev) == 0) {
                       mdev->driver = maple_drv;
                       return 1;
               }
       }
       return 0;
}

static void maple_detach_driver(struct maple_device *mdev)
{
       if (!mdev)
               return;
       if (mdev->driver) {
               if (mdev->driver->disconnect)
                       mdev->driver->disconnect(mdev);
       }
       mdev->driver = NULL;
       if (mdev->registered) {
               maple_release_device(&mdev->dev);
               device_unregister(&mdev->dev);
       }
       mdev->registered = 0;
       maple_free_dev(mdev);
}

/* process initial MAPLE_COMMAND_DEVINFO for each device or port */
static void maple_attach_driver(struct maple_device *dev)
{
       char *p;

       char *recvbuf;
       unsigned long function;
       int matched, retval;

       recvbuf = dev->mq->recvbuf;
       memcpy(&dev->devinfo, recvbuf + 4, sizeof(dev->devinfo));
       memcpy(dev->product_name, dev->devinfo.product_name, 30);
       memcpy(dev->product_licence, dev->devinfo.product_licence, 60);
       dev->product_name[30] = '\0';
       dev->product_licence[60] = '\0';

       for (p = dev->product_name + 29; dev->product_name <= p; p--)
               if (*p == ' ')
                       *p = '\0';
               else
                       break;

       for (p = dev->product_licence + 59; dev->product_licence <= p; p--)
               if (*p == ' ')
                       *p = '\0';
               else
                       break;

       function = be32_to_cpu(dev->devinfo.function);

       if (function > 0x200) {
               /* Do this silently - as not a real device */
               function = 0;
               dev->driver = &maple_dummy_driver;
               sprintf(dev->dev.bus_id, "%d:0.port", dev->port);
       } else {
               printk(KERN_INFO
                      "Maple bus at (%d, %d): Connected function 0x%lX\n",
                      dev->port, dev->unit, function);

               matched =
                   bus_for_each_drv(&maple_bus_type, NULL, dev,
                                    attach_matching_maple_driver);

               if (matched == 0) {
                       /* Driver does not exist yet */
                       printk(KERN_INFO
                              "No maple driver found for this device\n");
                       dev->driver = &maple_dummy_driver;
               }

               sprintf(dev->dev.bus_id, "%d:0%d.%lX", dev->port,
                       dev->unit, function);
       }
       dev->function = function;
       dev->dev.bus = &maple_bus_type;
       dev->dev.parent = &maple_bus;
       dev->dev.release = &maple_release_device;
       retval = device_register(&dev->dev);
       if (retval) {
               printk(KERN_INFO
                      "Maple bus: Attempt to register device (%x, %x) failed.\n",
                      dev->port, dev->unit);
               maple_free_dev(dev);
       }
       dev->registered = 1;
}

/*
 * if device has been registered for the given
 * port and unit then return 1 - allows identification
 * of which devices need to be attached or detached
 */
static int detach_maple_device(struct device *device, void *portptr)
{
       struct maple_device_specify *ds;
       struct maple_device *mdev;

       ds = portptr;
       mdev = to_maple_dev(device);
       if (mdev->port == ds->port && mdev->unit == ds->unit)
               return 1;
       return 0;
}

static int setup_maple_commands(struct device *device, void *ignored)
{
       struct maple_device *maple_dev = to_maple_dev(device);

       if ((maple_dev->interval > 0)
           && time_after(jiffies, maple_dev->when)) {
               maple_dev->when = jiffies + maple_dev->interval;
               maple_dev->mq->command = MAPLE_COMMAND_GETCOND;
               maple_dev->mq->sendbuf = &maple_dev->function;
               maple_dev->mq->length = 1;
               maple_add_packet(maple_dev->mq);
               liststatus++;
       } else {
               if (time_after(jiffies, maple_pnp_time)) {
                       maple_dev->mq->command = MAPLE_COMMAND_DEVINFO;
                       maple_dev->mq->length = 0;