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Commit 6dd8c2e6 authored by Andrzej Pietrasiewicz's avatar Andrzej Pietrasiewicz Committed by Felipe Balbi
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usb: gadget: printer: allocate printer_dev instances dynamically 



With all the obstacles removed it is possible to allow more than one
instance of the printer function. Since the function requires allocating
character device region, a maximum number of allowed instances is defined.
Such an approach is used in f_acm and in f_hid.
With multiple instances it does not make sense to depend on a
lock_printer_io member of a dynamically allocated (and destroyed) struct
printer_dev to clean up after all instances of the printer function.

Signed-off-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
parent 636bc0ed

drivers/usb/gadget/legacy/printer.c

+40 −22
Original line number Diff line number Diff line
@@ -51,11 +51,12 @@ USB_GADGET_COMPOSITE_OPTIONS(); 
#define GET_PORT_STATUS		1

#define SOFT_RESET		2



#define PRINTER_MINORS		4



static const char shortname [] = "printer";

static const char driver_desc [] = DRIVER_DESC;



static dev_t g_printer_devno;



static int major, minors;

static struct class *usb_gadget_class;



/*-------------------------------------------------------------------------*/
@@ -84,6 +85,7 @@ struct printer_dev { 
	u8			*current_rx_buf;

	u8			printer_status;

	u8			reset_printer;

	int			minor;

	struct cdev		printer_cdev;

	u8			printer_cdev_open;

	wait_queue_head_t	wait;
@@ -97,8 +99,6 @@ static inline struct printer_dev *func_to_printer(struct usb_function *f) 
	return container_of(f, struct printer_dev, function);

}



static struct printer_dev usb_printer_gadget;



/*-------------------------------------------------------------------------*/



/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
@@ -1096,6 +1096,7 @@ static int __init printer_func_bind(struct usb_configuration *c, 
	struct usb_ep *in_ep;

	struct usb_ep *out_ep = NULL;

	struct usb_request *req;

	dev_t devt;

	int id;

	int ret;

	u32 i;
@@ -1153,8 +1154,9 @@ static int __init printer_func_bind(struct usb_configuration *c, 
	}



	/* Setup the sysfs files for the printer gadget. */

	pdev = device_create(usb_gadget_class, NULL, g_printer_devno,

				  NULL, "g_printer");

	devt = MKDEV(major, dev->minor);

	pdev = device_create(usb_gadget_class, NULL, devt,

				  NULL, "g_printer%d", dev->minor);

	if (IS_ERR(pdev)) {

		ERROR(dev, "Failed to create device: g_printer\n");

		ret = PTR_ERR(pdev);
@@ -1167,7 +1169,7 @@ static int __init printer_func_bind(struct usb_configuration *c, 
	 */

	cdev_init(&dev->printer_cdev, &printer_io_operations);

	dev->printer_cdev.owner = THIS_MODULE;

	ret = cdev_add(&dev->printer_cdev, g_printer_devno, 1);

	ret = cdev_add(&dev->printer_cdev, devt, 1);

	if (ret) {

		ERROR(dev, "Failed to open char device\n");

		goto fail_cdev_add;
@@ -1176,7 +1178,7 @@ static int __init printer_func_bind(struct usb_configuration *c, 
	return 0;



fail_cdev_add:

	device_destroy(usb_gadget_class, g_printer_devno);

	device_destroy(usb_gadget_class, devt);



fail_rx_reqs:

	while (!list_empty(&dev->rx_reqs)) {
@@ -1204,7 +1206,7 @@ static void printer_func_unbind(struct usb_configuration *c, 


	dev = func_to_printer(f);



	device_destroy(usb_gadget_class, g_printer_devno);

	device_destroy(usb_gadget_class, MKDEV(major, dev->minor));



	/* Remove Character Device */

	cdev_del(&dev->printer_cdev);
@@ -1238,6 +1240,7 @@ static void printer_func_unbind(struct usb_configuration *c, 
		printer_req_free(dev->out_ep, req);

	}

	usb_free_all_descriptors(f);

	kfree(dev);

}



static int printer_func_set_alt(struct usb_function *f,
@@ -1271,14 +1274,21 @@ static struct usb_configuration printer_cfg_driver = { 
};



static int f_printer_bind_config(struct usb_configuration *c, char *pnp_str,

				 char *pnp_string, unsigned q_len)

				 char *pnp_string, unsigned q_len, int minor)

{

	struct printer_dev	*dev;

	int			status = -ENOMEM;

	size_t			len;



	dev = &usb_printer_gadget;

	if (minor >= minors)

		return -ENOENT;



	dev = kzalloc(sizeof(*dev), GFP_KERNEL);

	if (!dev)

		return -ENOMEM;



	dev->pnp_string = pnp_string;

	dev->minor = minor;



	dev->function.name = shortname;

	dev->function.bind = printer_func_bind;
@@ -1315,8 +1325,10 @@ static int f_printer_bind_config(struct usb_configuration *c, char *pnp_str, 
	dev->q_len = q_len;



	status = usb_add_function(c, &dev->function);

	if (status)

	if (status) {

		kfree(dev);

		return status;

	}

	INFO(dev, "%s, version: " DRIVER_VERSION "\n", driver_desc);

	return 0;

}
@@ -1335,43 +1347,51 @@ static int __init printer_do_config(struct usb_configuration *c) 
		printer_cfg_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;

	}



	return f_printer_bind_config(c, iPNPstring, pnp_string, QLEN);



	return f_printer_bind_config(c, iPNPstring, pnp_string, QLEN, 0);

}



static int gprinter_setup(void)

static int gprinter_setup(int count)

{

	int status;

	dev_t devt;



	usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");

	if (IS_ERR(usb_gadget_class)) {

		status = PTR_ERR(usb_gadget_class);

		usb_gadget_class = NULL;

		pr_err("unable to create usb_gadget class %d\n", status);

		return status;

	}



	status = alloc_chrdev_region(&g_printer_devno, 0, 1,

			"USB printer gadget");

	status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");

	if (status) {

		pr_err("alloc_chrdev_region %d\n", status);

		class_destroy(usb_gadget_class);

		usb_gadget_class = NULL;

		return status;

	}



	major = MAJOR(devt);

	minors = count;



	return status;

}



/* must be called with struct printer_dev's lock_printer_io held */

static void gprinter_cleanup(void)

{

	unregister_chrdev_region(g_printer_devno, 1);

	if (major) {

		unregister_chrdev_region(MKDEV(major, 0), minors);

		major = minors = 0;

	}

	class_destroy(usb_gadget_class);

	usb_gadget_class = NULL;

}



static int __init printer_bind(struct usb_composite_dev *cdev)

{

	int ret;



	ret = gprinter_setup();

	ret = gprinter_setup(PRINTER_MINORS);

	if (ret)

		return ret;
@@ -1418,9 +1438,7 @@ module_init(init); 
static void __exit

cleanup(void)

{

	mutex_lock(&usb_printer_gadget.lock_printer_io);

	usb_composite_unregister(&printer_driver);

	mutex_unlock(&usb_printer_gadget.lock_printer_io);

}

module_exit(cleanup);