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-rw-r--r--Documentation/ABI/testing/configfs-usb-gadget-printer9
-rw-r--r--Documentation/usb/gadget-testing.txt47
-rw-r--r--drivers/usb/gadget/Kconfig13
-rw-r--r--drivers/usb/gadget/function/f_printer.c130
-rw-r--r--drivers/usb/gadget/function/u_printer.h7
5 files changed, 204 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-printer b/Documentation/ABI/testing/configfs-usb-gadget-printer
new file mode 100644
index 000000000000..6b0714e3c605
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-usb-gadget-printer
@@ -0,0 +1,9 @@
+What: /config/usb-gadget/gadget/functions/printer.name
+Date: Apr 2015
+KernelVersion: 4.1
+Description:
+ The attributes:
+
+ pnp_string - Data to be passed to the host in pnp string
+ q_len - Number of requests per endpoint
+
diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt
index 076ac7ba7f93..f45b2bf4b41d 100644
--- a/Documentation/usb/gadget-testing.txt
+++ b/Documentation/usb/gadget-testing.txt
@@ -19,6 +19,7 @@ provided by gadgets.
16. UAC1 function
17. UAC2 function
18. UVC function
+19. PRINTER function
1. ACM function
@@ -726,3 +727,49 @@ with these patches:
http://www.spinics.net/lists/linux-usb/msg99220.html
host: luvcview -f yuv
+
+19. PRINTER function
+====================
+
+The function is provided by usb_f_printer.ko module.
+
+Function-specific configfs interface
+------------------------------------
+
+The function name to use when creating the function directory is "printer".
+The printer function provides these attributes in its function directory:
+
+ pnp_string - Data to be passed to the host in pnp string
+ q_len - Number of requests per endpoint
+
+Testing the PRINTER function
+----------------------------
+
+The most basic testing:
+
+device: run the gadget
+# ls -l /devices/virtual/usb_printer_gadget/
+
+should show g_printer<number>.
+
+If udev is active, then /dev/g_printer<number> should appear automatically.
+
+host:
+
+If udev is active, then e.g. /dev/usb/lp0 should appear.
+
+host->device transmission:
+
+device:
+# cat /dev/g_printer<number>
+host:
+# cat > /dev/usb/lp0
+
+device->host transmission:
+
+# cat > /dev/g_printer<number>
+host:
+# cat /dev/usb/lp0
+
+More advanced testing can be done with the prn_example
+described in Documentation/usb/gadget-printer.txt.
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 9d507cf98f94..3bb0e67fded2 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -437,6 +437,19 @@ config USB_CONFIGFS_F_UVC
device. It provides a userspace API to process UVC control requests
and stream video data to the host.
+config USB_CONFIGFS_F_PRINTER
+ bool "Printer function"
+ select USB_F_PRINTER
+ help
+ The Printer function channels data between the USB host and a
+ userspace program driving the print engine. The user space
+ program reads and writes the device file /dev/g_printer<X> to
+ receive or send printer data. It can use ioctl calls to
+ the device file to get or set printer status.
+
+ For more information, see Documentation/usb/gadget_printer.txt
+ which includes sample code for accessing the device file.
+
source "drivers/usb/gadget/legacy/Kconfig"
endchoice
diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index 7afe17d76f17..757fcf070013 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -1140,6 +1140,117 @@ static void printer_func_disable(struct usb_function *f)
spin_unlock_irqrestore(&dev->lock, flags);
}
+static inline struct f_printer_opts
+*to_f_printer_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_printer_opts,
+ func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_printer_opts);
+CONFIGFS_ATTR_OPS(f_printer_opts);
+
+static void printer_attr_release(struct config_item *item)
+{
+ struct f_printer_opts *opts = to_f_printer_opts(item);
+
+ usb_put_function_instance(&opts->func_inst);
+}
+
+static struct configfs_item_operations printer_item_ops = {
+ .release = printer_attr_release,
+ .show_attribute = f_printer_opts_attr_show,
+ .store_attribute = f_printer_opts_attr_store,
+};
+
+static ssize_t f_printer_opts_pnp_string_show(struct f_printer_opts *opts,
+ char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = strlcpy(page, opts->pnp_string + 2, PNP_STRING_LEN - 2);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_printer_opts_pnp_string_store(struct f_printer_opts *opts,
+ const char *page, size_t len)
+{
+ int result, l;
+
+ mutex_lock(&opts->lock);
+ result = strlcpy(opts->pnp_string + 2, page, PNP_STRING_LEN - 2);
+ l = strlen(opts->pnp_string + 2) + 2;
+ opts->pnp_string[0] = (l >> 8) & 0xFF;
+ opts->pnp_string[1] = l & 0xFF;
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static struct f_printer_opts_attribute f_printer_opts_pnp_string =
+ __CONFIGFS_ATTR(pnp_string, S_IRUGO | S_IWUSR,
+ f_printer_opts_pnp_string_show,
+ f_printer_opts_pnp_string_store);
+
+static ssize_t f_printer_opts_q_len_show(struct f_printer_opts *opts,
+ char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d\n", opts->q_len);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_printer_opts_q_len_store(struct f_printer_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u16 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou16(page, 0, &num);
+ if (ret)
+ goto end;
+
+ if (num > 65535) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ opts->q_len = (unsigned)num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_printer_opts_attribute f_printer_opts_q_len =
+ __CONFIGFS_ATTR(q_len, S_IRUGO | S_IWUSR, f_printer_opts_q_len_show,
+ f_printer_opts_q_len_store);
+
+static struct configfs_attribute *printer_attrs[] = {
+ &f_printer_opts_pnp_string.attr,
+ &f_printer_opts_q_len.attr,
+ NULL,
+};
+
+static struct config_item_type printer_func_type = {
+ .ct_item_ops = &printer_item_ops,
+ .ct_attrs = printer_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
static inline int gprinter_get_minor(void)
{
return ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
@@ -1180,6 +1291,7 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
if (!opts)
return ERR_PTR(-ENOMEM);
+ mutex_init(&opts->lock);
opts->func_inst.free_func_inst = gprinter_free_inst;
ret = &opts->func_inst;
@@ -1201,6 +1313,8 @@ static struct usb_function_instance *gprinter_alloc_inst(void)
if (idr_is_empty(&printer_ida.idr))
gprinter_cleanup();
}
+ config_group_init_type_name(&opts->func_inst.group, "",
+ &printer_func_type);
unlock:
mutex_unlock(&printer_ida_lock);
@@ -1210,8 +1324,13 @@ unlock:
static void gprinter_free(struct usb_function *f)
{
struct printer_dev *dev = func_to_printer(f);
+ struct f_printer_opts *opts;
+ opts = container_of(f->fi, struct f_printer_opts, func_inst);
kfree(dev);
+ mutex_lock(&opts->lock);
+ --opts->refcnt;
+ mutex_unlock(&opts->lock);
}
static void printer_func_unbind(struct usb_configuration *c,
@@ -1265,16 +1384,23 @@ static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
opts = container_of(fi, struct f_printer_opts, func_inst);
- if (opts->minor >= minors)
+ mutex_lock(&opts->lock);
+ if (opts->minor >= minors) {
+ mutex_unlock(&opts->lock);
return ERR_PTR(-ENOENT);
+ }
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
- if (!dev)
+ if (!dev) {
+ mutex_unlock(&opts->lock);
return ERR_PTR(-ENOMEM);
+ }
+ ++opts->refcnt;
dev->minor = opts->minor;
dev->pnp_string = opts->pnp_string;
dev->q_len = opts->q_len;
+ mutex_unlock(&opts->lock);
dev->function.name = "printer";
dev->function.bind = printer_func_bind;
diff --git a/drivers/usb/gadget/function/u_printer.h b/drivers/usb/gadget/function/u_printer.h
index b2338cacdfe4..0e2c49d4274e 100644
--- a/drivers/usb/gadget/function/u_printer.h
+++ b/drivers/usb/gadget/function/u_printer.h
@@ -25,6 +25,13 @@ struct f_printer_opts {
int minor;
char pnp_string[PNP_STRING_LEN];
unsigned q_len;
+
+ /*
+ * Protect the data from concurrent access by read/write
+ * and create symlink/remove symlink
+ */
+ struct mutex lock;
+ int refcnt;
};
#endif /* U_PRINTER_H */