usb: gadget: f_loopback: add configfs support
Add support for using the loopback USB function in gadgets composed with
configfs.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_loopback.c b/drivers/usb/gadget/f_loopback.c
index b790653..c35bb40 100644
--- a/drivers/usb/gadget/f_loopback.c
+++ b/drivers/usb/gadget/f_loopback.c
@@ -231,6 +231,14 @@
static void lb_free_func(struct usb_function *f)
{
+ struct f_lb_opts *opts;
+
+ opts = container_of(f->fi, struct f_lb_opts, func_inst);
+
+ mutex_lock(&opts->lock);
+ opts->refcnt--;
+ mutex_unlock(&opts->lock);
+
usb_free_all_descriptors(f);
kfree(func_to_loop(f));
}
@@ -386,6 +394,11 @@
return ERR_PTR(-ENOMEM);
lb_opts = container_of(fi, struct f_lb_opts, func_inst);
+
+ mutex_lock(&lb_opts->lock);
+ lb_opts->refcnt++;
+ mutex_unlock(&lb_opts->lock);
+
buflen = lb_opts->bulk_buflen;
qlen = lb_opts->qlen;
if (!qlen)
@@ -402,6 +415,118 @@
return &loop->function;
}
+static inline struct f_lb_opts *to_f_lb_opts(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_lb_opts,
+ func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_lb_opts);
+CONFIGFS_ATTR_OPS(f_lb_opts);
+
+static void lb_attr_release(struct config_item *item)
+{
+ struct f_lb_opts *lb_opts = to_f_lb_opts(item);
+
+ usb_put_function_instance(&lb_opts->func_inst);
+}
+
+static struct configfs_item_operations lb_item_ops = {
+ .release = lb_attr_release,
+ .show_attribute = f_lb_opts_attr_show,
+ .store_attribute = f_lb_opts_attr_store,
+};
+
+static ssize_t f_lb_opts_qlen_show(struct f_lb_opts *opts, char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->qlen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_lb_opts_qlen_store(struct f_lb_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->qlen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_lb_opts_attribute f_lb_opts_qlen =
+ __CONFIGFS_ATTR(qlen, S_IRUGO | S_IWUSR,
+ f_lb_opts_qlen_show,
+ f_lb_opts_qlen_store);
+
+static ssize_t f_lb_opts_bulk_buflen_show(struct f_lb_opts *opts, char *page)
+{
+ int result;
+
+ mutex_lock(&opts->lock);
+ result = sprintf(page, "%d", opts->bulk_buflen);
+ mutex_unlock(&opts->lock);
+
+ return result;
+}
+
+static ssize_t f_lb_opts_bulk_buflen_store(struct f_lb_opts *opts,
+ const char *page, size_t len)
+{
+ int ret;
+ u32 num;
+
+ mutex_lock(&opts->lock);
+ if (opts->refcnt) {
+ ret = -EBUSY;
+ goto end;
+ }
+
+ ret = kstrtou32(page, 0, &num);
+ if (ret)
+ goto end;
+
+ opts->bulk_buflen = num;
+ ret = len;
+end:
+ mutex_unlock(&opts->lock);
+ return ret;
+}
+
+static struct f_lb_opts_attribute f_lb_opts_bulk_buflen =
+ __CONFIGFS_ATTR(buflen, S_IRUGO | S_IWUSR,
+ f_lb_opts_bulk_buflen_show,
+ f_lb_opts_bulk_buflen_store);
+
+static struct configfs_attribute *lb_attrs[] = {
+ &f_lb_opts_qlen.attr,
+ &f_lb_opts_bulk_buflen.attr,
+ NULL,
+};
+
+static struct config_item_type lb_func_type = {
+ .ct_item_ops = &lb_item_ops,
+ .ct_attrs = lb_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
static void lb_free_instance(struct usb_function_instance *fi)
{
struct f_lb_opts *lb_opts;
@@ -417,7 +542,14 @@
lb_opts = kzalloc(sizeof(*lb_opts), GFP_KERNEL);
if (!lb_opts)
return ERR_PTR(-ENOMEM);
+ mutex_init(&lb_opts->lock);
lb_opts->func_inst.free_func_inst = lb_free_instance;
+ lb_opts->bulk_buflen = GZERO_BULK_BUFLEN;
+ lb_opts->qlen = GZERO_QLEN;
+
+ config_group_init_type_name(&lb_opts->func_inst.group, "",
+ &lb_func_type);
+
return &lb_opts->func_inst;
}
DECLARE_USB_FUNCTION(Loopback, loopback_alloc_instance, loopback_alloc);