From 6dd8c2e69521ec9d7b23a741294702f844353f1a Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Tue, 3 Mar 2015 10:52:26 +0100 Subject: [PATCH] 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: Andrzej Pietrasiewicz Signed-off-by: Felipe Balbi --- drivers/usb/gadget/legacy/printer.c | 62 ++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 22 deletions(-) diff --git a/drivers/usb/gadget/legacy/printer.c b/drivers/usb/gadget/legacy/printer.c index c059af1..d1f85f8 100644 --- a/drivers/usb/gadget/legacy/printer.c +++ b/drivers/usb/gadget/legacy/printer.c @@ -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); -- 2.7.4