This patch adds support for Sega's proprietary Maple bus - which is
required to support the Dreamcast's peripherals.
This driver represents a substantial re-write of the old 2.4 driver.
Signed-off by: Adrian McMenamin <[email protected]>
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 54878f0..c1771b7 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -702,6 +702,17 @@ config CF_BASE_ADDR
default "0xb8000000" if CF_AREA6
default "0xb4000000" if CF_AREA5
+config MAPLE
+ tristate "Maple Bus Support"
+ depends on SH_DREAMCAST
+ help
+ The Maple Bus is SEGA's serial communication bus for peripherals
+ on the Dreamcast. Without this bus support you won't be able to
+ get your Dreamcast keyboard etc to work, so most users
+ probably want to say 'Y' here, unless you are only using the
+ Dreamcast with a serial line terminal or a remote network
+ connection.
+
source "arch/sh/drivers/pci/Kconfig"
source "drivers/pci/Kconfig"
diff --git a/drivers/sh/Makefile b/drivers/sh/Makefile
index 8a14389..f0a1f4f 100644
--- a/drivers/sh/Makefile
+++ b/drivers/sh/Makefile
@@ -3,4 +3,5 @@
#
obj-$(CONFIG_SUPERHYWAY) += superhyway/
+obj-$(CONFIG_MAPLE) += maple/
diff --git a/drivers/sh/maple/Makefile b/drivers/sh/maple/Makefile
new file mode 100644
index 0000000..f8c39f2
--- /dev/null
+++ b/drivers/sh/maple/Makefile
@@ -0,0 +1,3 @@
+#Makefile for Maple Bus
+
+obj-y := maplebus.o
diff --git a/drivers/sh/maple/maplebus.c b/drivers/sh/maple/maplebus.c
new file mode 100644
index 0000000..0f2223c
--- /dev/null
+++ b/drivers/sh/maple/maplebus.c
@@ -0,0 +1,737 @@
+/* maplebus.c
+ * Core maple bus functionality
+ * Original 2.4 code used here copyright
+ * YAEGASHI Takeshi, Paul Mundt, M. R. Brown and others
+ * Porting to 2.6 Copyright Adrian McMenamin, 2007
+ *
+ * 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. 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, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/maple.h>
+#include <asm/cacheflush.h>
+#include <asm/dma.h>
+#include <asm/mach/sysasic.h>
+
+MODULE_AUTHOR("Yaegshi Takeshi, Paul Mundt, MR Brown, Adrian McMenamin");
+MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
+MODULE_LICENSE("GPL");
+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 struct maple_driver maple_null_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_cache;
+
+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);
+
+void maplebus_init_hardware(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);
+}
+EXPORT_SYMBOL_GPL(maplebus_init_hardware);
+
+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 = 0;
+}
+EXPORT_SYMBOL_GPL(maple_getcond_callback);
+
+int maple_dma_done(void)
+{
+ return (ctrl_inl(MAPLE_STATE) & 1) == 0;
+}
+EXPORT_SYMBOL_GPL(maple_dma_done);
+
+static void maple_release_device(struct device *dev)
+{
+ if (dev->type) {
+ kfree(dev->type->name);
+ kfree(dev->type);
+ }
+}
+
+void maple_add_packet(struct mapleq *mq)
+{
+ list_add((struct list_head *) mq, &maple_waitq);
+}
+
+static struct mapleq *maple_allocq(struct maple_device *dev)
+{
+ struct mapleq *mq;
+
+ mq = kmalloc(sizeof(*mq), GFP_KERNEL);
+ if (unlikely(!mq))
+ return NULL;
+
+ mq->dev = dev;
+ mq->recvbuf = kmem_cache_zalloc(maple_cache, GFP_KERNEL);
+ if (unlikely(!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 (unlikely(!dev))
+ return NULL;
+
+ dev->port = port;
+ dev->unit = unit;
+ dev->mq = maple_allocq(dev);
+
+ if (unlikely(!dev->mq)) {
+ kfree(dev);
+ return NULL;
+ }
+
+ return dev;
+}
+
+static void maple_free_dev(struct maple_device *mdev)
+{
+ if (!mdev)
+ return;
+ kmem_cache_free(maple_cache, mdev->mq->recvbuf);
+ kfree(mdev->mq);
+ kfree(mdev);
+}
+
+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++;
+}
+
+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 (unlikely(maple_packets++ > MAPLE_MAXPACKETS))
+ break;
+ }
+ if (maple_packets > 0) {
+ for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
+ dma_cache_wback_inv(maple_sendbuf + i * PAGE_SIZE,
+ PAGE_SIZE);
+ }
+}
+
+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 (unlikely
+ (mdev->devinfo.function & be32_to_cpu(maple_drv->function))) {
+ if (likely(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);
+}
+
+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 (unlikely(function == 0xFFFFFFFF)) {
+ /* Do this silently - as not a real device */
+ function = 0;
+ dev->driver = &maple_null_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_null_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 device_specify *ds;
+ struct maple_device *mdev;
+
+ ds = portptr;
+ mdev = to_maple_dev(device);
+ if (unlikely(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 (likely(maple_dev->interval > 0)) {
+ if (likely(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 (jiffies >= maple_pnp_time) {
+ maple_dev->mq->command = MAPLE_COMMAND_DEVINFO;
+ maple_dev->mq->length = 0;
+ maple_add_packet(maple_dev->mq);
+ liststatus++;
+ }
+ }
+
+ return 0;
+}
+
+static void maple_vblank_handler(struct work_struct *work)
+{
+ /* Turn off Maple DMA while we do this */
+ if (unlikely(!maple_dma_done()))
+ return;
+ if (unlikely(!list_empty(&maple_sentq)))
+ return;
+ ctrl_outl(0, MAPLE_ENABLE);
+ liststatus = 0;
+ bus_for_each_dev(&maple_bus_type, NULL, NULL,
+ setup_maple_commands);
+ if (jiffies >= maple_pnp_time)
+ maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
+ if (likely(liststatus && list_empty(&maple_sentq))) {
+ INIT_LIST_HEAD(&maple_sentq);
+ maple_send();
+ }
+ maplebus_init_hardware();
+}
+
+static void maple_map_subunits(struct maple_device *mdev, int submask)
+{
+ int retval, k, devcheck;
+ struct maple_device *mdev_add;
+ struct device_specify ds;
+
+ for (k = 0; k < 5; k++) {
+ ds.port = mdev->port;
+ ds.unit = k + 1;
+ retval =
+ bus_for_each_dev(&maple_bus_type, NULL, &ds,
+ detach_maple_device);
+ if (retval) {
+ submask = submask >> 1;
+ continue;
+ }
+ devcheck = submask & 0x01;
+ if (unlikely(devcheck)) {
+ mdev_add = maple_alloc_dev(mdev->port, k + 1);
+ mdev_add->mq->command = MAPLE_COMMAND_DEVINFO;
+ mdev_add->mq->length = 0;
+ maple_add_packet(mdev_add->mq);
+ scanning = 1;
+ }
+ submask = submask >> 1;
+ }
+}
+
+static void maple_clean_submap(struct maple_device *mdev)
+{
+ int killbit;
+
+ killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
+ killbit = ~killbit;
+ killbit &= 0xFF;
+ subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
+}
+
+static void maple_response_none(struct maple_device *mdev,
+ struct mapleq *mq)
+{
+ if (unlikely(!started)) {
+ printk(KERN_INFO "No maple devices attached to port %d\n",
+ mdev->port);
+ maple_attach_driver(mdev);
+ return;
+ }
+ if (unlikely(mdev->unit != 0)) {
+ list_del(&mq->list);
+ maple_detach_driver(mdev);
+ maple_clean_submap(mdev);
+ printk(KERN_INFO "Maple bus detaching at (%d, %d)\n",
+ mdev->port, mdev->unit);
+ return;
+ }
+ maple_clean_submap(mdev);
+}
+
+static void maple_response_devinfo(struct maple_device *mdev,
+ char *recvbuf)
+{
+ char submask;
+ if ((unlikely(!started)) || (unlikely(scanning == 2))) {
+ maple_attach_driver(mdev);
+ return;
+ }
+ if (likely(mdev->unit == 0)) {
+ submask = recvbuf[2] & 0x1F;
+ if (unlikely(submask ^ subdevice_map[mdev->port])) {
+ maple_map_subunits(mdev, submask);
+ subdevice_map[mdev->port] = submask;
+ }
+ }
+}
+
+static void maple_dma_handler(struct work_struct *work)
+{
+ struct mapleq *mq, *nmq;
+ struct maple_device *dev;
+ char *recvbuf;
+ enum maple_code code;
+
+ if (unlikely(!maple_dma_done()))
+ return;
+ ctrl_outl(0, MAPLE_ENABLE);
+
+ /* Be extra cautious and check new DMA cycle not already underway */
+ if (likely(!list_empty(&maple_sentq))) {
+ list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
+ recvbuf = mq->recvbuf;
+ code = recvbuf[0];
+ dev = mq->dev;
+ switch (code) {
+ case MAPLE_RESPONSE_NONE:
+ maple_response_none(dev, mq);
+ break;
+
+ case MAPLE_RESPONSE_DEVINFO:
+ maple_response_devinfo(dev, recvbuf);
+ break;
+
+ case MAPLE_RESPONSE_DATATRF:
+ if (dev->callback)
+ dev->callback(mq);
+ break;
+
+ case MAPLE_RESPONSE_FILEERR:
+ case MAPLE_RESPONSE_AGAIN:
+ case MAPLE_RESPONSE_BADCMD:
+ case MAPLE_RESPONSE_BADFUNC:
+ printk(KERN_DEBUG
+ "Maple non-fatal error 0x%X\n",
+ code);
+ break;
+
+ case MAPLE_RESPONSE_ALLINFO:
+ printk(KERN_DEBUG
+ "Maple - extended device information not supported\n");
+ break;
+
+ case MAPLE_RESPONSE_OK:
+ break;
+
+ default:
+ break;
+ }
+ }
+ INIT_LIST_HEAD(&maple_sentq);
+ if (unlikely(scanning == 1)) {
+ maple_send();
+ scanning = 2;
+ } else
+ scanning = 0;
+
+ if (unlikely(started == 0))
+ started = 1;
+ }
+ maplebus_init_hardware();
+}
+
+static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
+{
+ /* Load everything into the bottom half */
+ schedule_work(&maple_dma_process);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t maplebus_vblank_interrupt(int irq, void *dev_id)
+{
+ schedule_work(&maple_vblank_process);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction maple_dma_irq = {
+ .name = "maple bus DMA handler",
+ .handler = maplebus_dma_interrupt,
+ .flags = IRQF_SHARED,
+};
+
+static struct irqaction maple_vblank_irq = {
+ .name = "maple bus VBLANK handler",
+ .handler = maplebus_vblank_interrupt,
+ .flags = IRQF_SHARED,
+};
+
+static int maple_set_dma_interrupt_handler(void)
+{
+ return setup_irq(HW_EVENT_MAPLE_DMA, &maple_dma_irq);
+}
+
+static int maple_set_vblank_interrupt_handler(void)
+{
+ return setup_irq(HW_EVENT_VSYNC, &maple_vblank_irq);
+}
+
+static int maple_get_dma_buffer(void)
+{
+ maple_sendbuf =
+ (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
+ MAPLE_DMA_PAGES);
+ if (unlikely(!maple_sendbuf))
+ return -ENOMEM;
+ return 0;
+}
+
+static int match_maple_bus_driver(struct device *devptr,
+ struct device_driver *drvptr)
+{
+ struct maple_driver *maple_drv;
+ struct maple_device *maple_dev;
+
+ maple_drv = container_of(drvptr, struct maple_driver, drv);
+ maple_dev = container_of(devptr, struct maple_device, dev);
+ /* Trap empty port case */
+ if (unlikely(maple_dev->devinfo.function == 0xFFFFFFFF))
+ return 0;
+ else if (unlikely
+ (maple_dev->devinfo.function &
+ be32_to_cpu(maple_drv->function)))
+ return 1;
+ return 0;
+}
+
+static int maple_bus_uevent(struct device *dev, char **envp,
+ int num_envp, char *buffer, int buffer_size)
+{
+ return 0;
+}
+
+static void maple_bus_release(struct device *dev)
+{
+}
+
+static struct maple_driver maple_null_driver = {
+ .drv = {
+ .name = "Maple_bus_basic_driver",
+ .bus = &maple_bus_type,
+ },
+};
+
+struct bus_type maple_bus_type = {
+ .name = "maple",
+ .match = match_maple_bus_driver,
+ .uevent = maple_bus_uevent,
+};
+
+EXPORT_SYMBOL_GPL(maple_bus_type);
+
+static struct device maple_bus = {
+ .bus_id = "maple",
+ .release = maple_bus_release,
+};
+
+static int __init maple_bus_init(void)
+{
+ int retval, i;
+ struct maple_device *mdev[MAPLE_PORTS];
+ ctrl_outl(0, MAPLE_STATE);
+
+ retval = device_register(&maple_bus);
+ if (unlikely(retval))
+ goto cleanup;
+
+ retval = bus_register(&maple_bus_type);
+ if (unlikely(retval))
+ goto cleanup_device;
+
+ retval = driver_register(&maple_null_driver.drv);
+
+ if (unlikely(retval))
+ goto cleanup_bus;
+
+ /* allocate memory for maple bus dma */
+ retval = maple_get_dma_buffer();
+ if (unlikely(retval)) {
+ printk(KERN_INFO
+ "Maple bus: Failed to allocate Maple DMA buffers\n");
+ goto cleanup_basic;
+ }
+
+ /* set up DMA interrupt handler */
+ retval = maple_set_dma_interrupt_handler();
+ if (unlikely(retval)) {
+ printk(KERN_INFO
+ "Maple bus: Failed to grab maple DMA IRQ\n");
+ goto cleanup_dma;
+ }
+
+ /* set up VBLANK interrupt handler */
+ retval = maple_set_vblank_interrupt_handler();
+ if (unlikely(retval)) {
+ printk(KERN_INFO "Maple bus: Failed to grab VBLANK IRQ\n");
+ goto cleanup_irq;
+ }
+
+ maple_cache =
+ kmem_cache_create("Maplebus_cache", 0x400, 0,
+ SLAB_HWCACHE_ALIGN, NULL);
+
+ if (unlikely(!maple_cache))
+ goto cleanup_bothirqs;
+
+ /* setup maple ports */
+ for (i = 0; i < MAPLE_PORTS; i++) {
+ mdev[i] = maple_alloc_dev(i, 0);
+ if (unlikely(!mdev[i])) {
+ while (i-- > 0)
+ maple_free_dev(mdev[i]);
+ goto cleanup_cache;
+ }
+ mdev[i]->registered = 0;
+ mdev[i]->mq->command = MAPLE_COMMAND_DEVINFO;
+ mdev[i]->mq->length = 0;
+ maple_add_packet(mdev[i]->mq);
+ subdevice_map[i] = 0;
+ }
+
+ /* setup maplebus hardware */
+ maplebus_init_hardware();
+
+ /* initial detection */
+ maple_send();
+
+ maple_pnp_time = 0;
+
+ printk(KERN_INFO "Maple bus core now registered.\n");
+
+ return 0;
+
+ cleanup_cache:
+ kmem_cache_destroy(maple_cache);
+
+ cleanup_bothirqs:
+ free_irq(HW_EVENT_VSYNC, 0);
+
+ cleanup_irq:
+ free_irq(HW_EVENT_MAPLE_DMA, 0);
+
+ cleanup_dma:
+ free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
+
+ cleanup_basic:
+ driver_unregister(&maple_null_driver.drv);
+
+ cleanup_bus:
+ bus_unregister(&maple_bus_type);
+
+ cleanup_device:
+ device_unregister(&maple_bus);
+
+ cleanup:
+ printk(KERN_INFO "Maple bus registration failed\n");
+ return retval;
+}
+
+static int maple_remove_driver(struct device_driver *driver, void *ignored)
+{
+ driver_unregister(driver);
+ return 0;
+}
+
+static int maple_remove_device(struct device *dev, void *ignored)
+{
+ struct maple_device *mdev;
+ mdev = to_maple_dev(dev);
+ maple_detach_driver(mdev);
+ return 0;
+}
+
+static void __exit maple_bus_exit(void)
+{
+ int ignored;
+ free_irq(HW_EVENT_MAPLE_DMA, 0);
+ free_irq(HW_EVENT_VSYNC, 0);
+
+ ignored = bus_for_each_drv(&maple_bus_type, NULL, NULL,
+ maple_remove_driver);
+ ignored = bus_for_each_dev(&maple_bus_type, NULL, NULL,
+ maple_remove_device);
+
+ bus_unregister(&maple_bus_type);
+ device_unregister(&maple_bus);
+
+ kmem_cache_destroy(maple_cache);
+
+ if (likely(maple_sendbuf))
+ free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
+}
+
+/* use init call to ensure bus is registered ahead of devices */
+subsys_initcall(maple_bus_init);
+module_exit(maple_bus_exit);
diff --git a/include/linux/input.h b/include/linux/input.h
diff --git a/include/linux/maple.h b/include/linux/maple.h
new file mode 100644
index 0000000..1bb565d
--- /dev/null
+++ b/include/linux/maple.h
@@ -0,0 +1,126 @@
+/**
+ * maple.h
+ *
+ * porting to 2.6 driver model
+ * copyright Adrian McMenamin, 2007
+ *
+ */
+
+extern struct bus_type maple_bus_type;
+extern struct semaphore maple_mutex;
+
+#define MAPLE_PORTS 4
+#define MAPLE_PNP_INTERVAL HZ
+#define MAPLE_MAXPACKETS 8
+#define MAPLE_DMA_ORDER 14
+#define MAPLE_DMA_SIZE (1 << MAPLE_DMA_ORDER)
+#define MAPLE_DMA_PAGES ((MAPLE_DMA_ORDER > PAGE_SHIFT) ?
MAPLE_DMA_ORDER - PAGE_SHIFT : 0)
+
+/* Maple Bus registers */
+#define MAPLE_BASE 0xa05f6c00
+#define MAPLE_DMAADDR (MAPLE_BASE+0x04)
+#define MAPLE_TRIGTYPE (MAPLE_BASE+0x10)
+#define MAPLE_ENABLE (MAPLE_BASE+0x14)
+#define MAPLE_STATE (MAPLE_BASE+0x18)
+#define MAPLE_SPEED (MAPLE_BASE+0x80)
+#define MAPLE_RESET (MAPLE_BASE+0x8c)
+
+#define MAPLE_MAGIC 0x6155404f
+#define MAPLE_2MBPS 0
+#define MAPLE_TIMEOUT(n) ((n)<<15)
+
+/* Maple Bus command and response codes */
+enum maple_code {
+ MAPLE_RESPONSE_FILEERR = -5,
+ MAPLE_RESPONSE_AGAIN = -4, /* request should be retransmitted */
+ MAPLE_RESPONSE_BADCMD = -3,
+ MAPLE_RESPONSE_BADFUNC = -2,
+ MAPLE_RESPONSE_NONE = -1, /* unit didn't respond at all */
+ MAPLE_COMMAND_DEVINFO = 1,
+ MAPLE_COMMAND_ALLINFO = 2,
+ MAPLE_COMMAND_RESET = 3,
+ MAPLE_COMMAND_KILL = 4,
+ MAPLE_RESPONSE_DEVINFO = 5,
+ MAPLE_RESPONSE_ALLINFO = 6,
+ MAPLE_RESPONSE_OK = 7,
+ MAPLE_RESPONSE_DATATRF = 8,
+ MAPLE_COMMAND_GETCOND = 9,
+ MAPLE_COMMAND_GETMINFO = 10,
+ MAPLE_COMMAND_BREAD = 11,
+ MAPLE_COMMAND_BWRITE = 12,
+ MAPLE_COMMAND_SETCOND = 14
+};
+
+/* Function codes */
+
+#define MAPLE_FUNC_CONTROLLER 0x001
+#define MAPLE_FUNC_MEMCARD 0x002
+#define MAPLE_FUNC_LCD 0x004
+#define MAPLE_FUNC_CLOCK 0x008
+#define MAPLE_FUNC_MICROPHONE 0x010
+#define MAPLE_FUNC_ARGUN 0x020
+#define MAPLE_FUNC_KEYBOARD 0x040
+#define MAPLE_FUNC_LIGHTGUN 0x080
+#define MAPLE_FUNC_PURUPURU 0x100
+#define MAPLE_FUNC_MOUSE 0x200
+
+struct mapleq {
+ struct list_head list;
+ struct maple_device *dev;
+ void *sendbuf, *recvbuf;
+ unsigned char length;
+ enum maple_code command;
+};
+
+struct maple_devinfo {
+ unsigned long function;
+ unsigned long function_data[3];
+ unsigned char area_code;
+ unsigned char connector_directon;
+ char product_name[31];
+ char product_licence[61];
+ unsigned short standby_power;
+ unsigned short max_power;
+};
+
+struct maple_device {
+ struct maple_driver *driver;
+ struct mapleq *mq;
+ void *private_data;
+ void (*callback) (struct mapleq * mq);
+ unsigned long when, interval, function;
+ struct maple_devinfo devinfo;
+ unsigned char port, unit;
+ char product_name[32];
+ char product_licence[64];
+ int registered;
+ struct device dev;
+};
+
+struct maple_driver {
+ unsigned long function;
+ int (*connect) (struct maple_device * dev);
+ void (*disconnect) (struct maple_device * dev);
+ struct device_driver drv;
+};
+
+struct device_specify {
+ int port;
+ int unit;
+};
+
+void maple_getcond_callback(struct maple_device *dev,
+ void (*callback) (struct mapleq * mq),
+ unsigned long interval,
+ unsigned long function);
+
+void maple_setup_port_rescan(struct maple_device *mdev);
+
+void maplebus_init_hardware(void);
+
+int maple_dma_done(void);
+
+int maple_driver_register(struct device_driver *drv);
+
+#define to_maple_dev(n) container_of(n, struct maple_device, dev)
+#define to_maple_driver(n) container_of(n, struct maple_driver, drv)
On Sun, 9 Sep 2007 17:46:54 +0100
"Adrian McMenamin" <[email protected]> wrote:
> This patch adds support for Sega's proprietary Maple bus - which is
> required to support the Dreamcast's peripherals.
Hi,
in general the code looks clean; great job on that.
A few suggestions and comments to hopefully help this driver to become
even better:
First of all, I'm a little concerned about the lack of locking that
this driver seems to have; what guarantees the integrity of the lists
used in the driver?
Second, you have a lot of use of likely() and unlikely(); so much that I think it's waaaay overkill. The code it's in generally isn't hotpath, and gcc also does a pretty decent job without giving these hints in general.
> +
> +void maple_add_packet(struct mapleq *mq)
> +{
> + list_add((struct list_head *) mq, &maple_waitq);
> +}
for example this list.. what makes sure that no 2 pieces of code muck with it at the same time?
> +static struct maple_device *maple_alloc_dev(int port, int unit)
> +{
> + struct maple_device *dev;
> +
> + dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> + if (unlikely(!dev))
> + return NULL;
> +
> + dev->port = port;
> + dev->unit = unit;
> + dev->mq = maple_allocq(dev);
> +
> + if (unlikely(!dev->mq)) {
this unlikely isn't needed; gcc basically assumes that NULL pointer checks are unlikely anyway...
> +
> +static int setup_maple_commands(struct device *device, void *ignored)
> +{
> + struct maple_device *maple_dev = to_maple_dev(device);
> +
> + if (likely(maple_dev->interval > 0)) {
> + if (likely(jiffies > maple_dev->when)) {
this is I think a small bug; it is for sure unsafe against jiffies wrapping... please consider using the time_before() and time_after() helpers which will make this comparison safe wrt jiffies wrapping. The same is true for all other jiffies use in the driver...
> +static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
> +{
> + /* Load everything into the bottom half */
> + schedule_work(&maple_dma_process);
> + return IRQ_HANDLED;
> +}
I wonder if you want to at least check if the work was really for you before returning IRQ_HANDLED....
On 09/09/07, Arjan van de Ven <[email protected]> wrote:
> On Sun, 9 Sep 2007 17:46:54 +0100
> "Adrian McMenamin" <[email protected]> wrote:
>
> > This patch adds support for Sega's proprietary Maple bus - which is
> > required to support the Dreamcast's peripherals.
>
>
> First of all, I'm a little concerned about the lack of locking that
> this driver seems to have; what guarantees the integrity of the lists
> used in the driver?
>
Could you explain what you think the issue is? The lists are only
handled by this driver and not anything else.
> Second, you have a lot of use of likely() and unlikely(); so much that I think it's waaaay overkill. The code it's in generally isn't hotpath, and gcc also does a pretty decent job without giving these hints in general.
>
>
>
Fair enough.
> > +
> > +void maple_add_packet(struct mapleq *mq)
> > +{
> > + list_add((struct list_head *) mq, &maple_waitq);
> > +}
>
> for example this list.. what makes sure that no 2 pieces of code muck with it at the same time?
>
>
Because everything is handled by one kernel thread on a uniprocessor machine.
> > +static irqreturn_t maplebus_dma_interrupt(int irq, void *dev_id)
> > +{
> > + /* Load everything into the bottom half */
> > + schedule_work(&maple_dma_process);
> > + return IRQ_HANDLED;
> > +}
>
> I wonder if you want to at least check if the work was really for you before returning IRQ_HANDLED....
>
It's *always* for me - this is an end of DMA interrupt for the bus.
On Sun, 9 Sep 2007 19:36:52 +0100
"Adrian McMenamin" <[email protected]> wrote:
> Fair enough.
>
> > > +
> > > +void maple_add_packet(struct mapleq *mq)
> > > +{
> > > + list_add((struct list_head *) mq, &maple_waitq);
> > > +}
> >
> > for example this list.. what makes sure that no 2 pieces of code
> > muck with it at the same time?
> >
> >
>
> Because everything is handled by one kernel thread on a uniprocessor
> machine.
hmmm.... still. Once you look at it from any other place... preempt etc
etc... it's sort of playing russian roulette with an empty gun, but
without checking that the gun is actually empty... at some point
someone may accidentally leave a bullet in ;)