[RFC][patch] sh: maple: Dreamcast mouse driver

[RFC][patch] sh: maple: Dreamcast mouse driver

[Adrian McMenamin]

The last time I posted patches for maple devices there were a number of
problems, so this is a request for comments on the fix of the old mouse
driver.

Driver for mouse on the SEGA Dreamcast


Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>



---

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 4e99342..9e5c644 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -286,4 +286,17 @@ config MOUSE_GPIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called gpio_mouse.
 
+config MOUSE_MAPLE
+	tristate "Maple mouse (for Dreamcast)"
+	depends on MAPLE
+	help
+	  Say Y here to support the mouse on the SEGA Dreamcast.
+
+	  Most Dreamcast users (with a mouse) will want to say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called maplemouse.
+
+
 endif
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 96f1dd8..0272f5d 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_MOUSE_SERIAL)	+= sermouse.o
 obj-$(CONFIG_MOUSE_HIL)		+= hil_ptr.o
 obj-$(CONFIG_MOUSE_VSXXXAA)	+= vsxxxaa.o
 obj-$(CONFIG_MOUSE_GPIO)	+= gpio_mouse.o
+obj-$(CONFIG_MOUSE_MAPLE)	+= maplemouse.o
 
 psmouse-objs := psmouse-base.o synaptics.o
 
diff --git a/drivers/input/mouse/maplemouse.c b/drivers/input/mouse/maplemouse.c
new file mode 100644
index 0000000..4b8beb4
--- /dev/null
+++ b/drivers/input/mouse/maplemouse.c
@@ -0,0 +1,139 @@
+/*
+ *	SEGA Dreamcast mouse driver
+ *	Based on drivers/usb/usbmouse.c
+ *
+ *	Copyright Yaegashi Takeshi, 2001
+ *	Porting to 2.6 and other fixes
+ *	copyright, Adrian McMenamin, 2008
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/maple.h>
+
+MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
+MODULE_DESCRIPTION("SEGA Dreamcast mouse driver");
+MODULE_LICENSE("GPL");
+
+struct dc_mouse {
+	struct input_dev *dev;
+	struct maple_device *mdev;
+};
+
+static void dc_mouse_callback(struct mapleq *mq)
+{
+	int buttons, relx, rely, relz;
+	struct maple_device *mapledev = mq->dev;
+	struct dc_mouse *mse = maple_get_drvdata(mapledev);
+	struct input_dev *dev = mse->dev;
+	unsigned char *res = mq->recvbuf;
+
+	buttons = ~res[8];
+	relx = *(unsigned short *)(res + 12) - 512;
+	rely = *(unsigned short *)(res + 14) - 512;
+	relz = *(unsigned short *)(res + 16) - 512;
+
+	input_report_key(dev, BTN_LEFT,   buttons & 4);
+	input_report_key(dev, BTN_MIDDLE, buttons & 9);
+	input_report_key(dev, BTN_RIGHT,  buttons & 2);
+	input_report_rel(dev, REL_X,      relx);
+	input_report_rel(dev, REL_Y,      rely);
+	input_report_rel(dev, REL_WHEEL,  relz);
+	input_sync(dev);
+}
+
+/* allow the mouse to be used */
+static int probe_maple_mouse(struct device *dev)
+{
+	struct maple_device *mdev;
+	struct maple_driver *mdrv;
+	int error;
+	struct input_dev *input_dev;
+	struct dc_mouse *mse;
+
+
+	mdev = to_maple_dev(dev);
+	mdrv = to_maple_driver(dev->driver);
+	if (!mdrv||!mdev) {
+		error = EINVAL;
+		goto fail;
+	}
+
+	mse = kzalloc(sizeof(struct dc_mouse), GFP_KERNEL);
+	if (!mse) {
+		error = ENOMEM;
+		goto fail;
+	}
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		error = ENOMEM;
+		goto fail_nomem;
+	}
+
+	mse->dev = input_dev;
+	mse->mdev = mdev;
+
+	input_set_drvdata(input_dev, mse);
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
+	input_dev->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);
+	input_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y) | BIT_MASK(REL_WHEEL);
+	input_dev->name = mdev->product_name;
+	input_dev->id.bustype = BUS_HOST;
+	error =	input_register_device(input_dev);
+	if (error)
+		goto fail_register;
+
+	maple_getcond_callback(mdev, dc_mouse_callback, HZ/50, MAPLE_FUNC_MOUSE);
+
+	mdev->driver = mdrv;
+	maple_set_drvdata(mdev, mse);
+
+	return error;
+
+fail_register:
+	input_free_device(input_dev);
+fail_nomem:
+	kfree(mse);
+fail:
+	return -error;
+
+}
+
+static int remove_maple_mouse(struct device *dev)
+{
+	struct maple_device *mdev = to_maple_dev(dev);
+	struct dc_mouse *mse = maple_get_drvdata(mdev);
+
+	mdev->callback = NULL;
+	input_unregister_device(mse->dev);
+	maple_set_drvdata(mdev, NULL);
+	kfree(mse);
+	return 0;
+}
+
+static struct maple_driver dc_mouse_driver = {
+	.function =	MAPLE_FUNC_MOUSE,
+	.drv = {
+		.name = "Dreamcast_mouse",
+		.probe = probe_maple_mouse,
+		.remove = remove_maple_mouse,
+	},
+};
+
+static int __init dc_mouse_init(void)
+{
+	return maple_driver_register(&dc_mouse_driver);
+}
+
+static void __exit dc_mouse_exit(void)
+{
+	maple_driver_unregister(&dc_mouse_driver);
+}
+
+module_init(dc_mouse_init);
+module_exit(dc_mouse_exit);

Re: [RFC][patch] sh: maple: Dreamcast mouse driver

[Dmitry Torokhov]

Hi Adrian,

On Sunday 28 December 2008 15:49:57 Adrian McMenamin wrote:
> +
> +	mdev = to_maple_dev(dev);
> +	mdrv = to_maple_driver(dev->driver);
> +	if (!mdrv||!mdev) {
> +		error = EINVAL;
> +		goto fail;
> +	}

This still does not make sense, mdev and mdrv will never be NULL.

> +fail:
> +	return -error;

You just negated the error returned by input_register_device() and the module 
loading code will think that probe succeeded.

> +
> +static int remove_maple_mouse(struct device *dev)
> +{
> +	struct maple_device *mdev = to_maple_dev(dev);
> +	struct dc_mouse *mse = maple_get_drvdata(mdev);
> +
> +	mdev->callback = NULL;

I am uneasy about just whacking a NULL there. The other driver you sent 
implemented open and close methods and used maple_getcond_callback to 
manipulate callbacks which I assume is safer than just resetting the pointer.

-- 
Dmitry