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usb: gadget: printer: allocate printer_dev instances dynamically

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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: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Andrzej Pietrasiewicz 2015-03-03 10:52:26 +01:00 committed by Felipe Balbi
parent 636bc0ed27
commit 6dd8c2e695
1 changed files with 40 additions and 22 deletions
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62
drivers/usb/gadget/legacy/printer.c
View file

@ -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 @@ autoconf_fail:
}
/* 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 @@ autoconf_fail:
*/
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 @@ autoconf_fail:
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);