usb: gadget: f_sourcesink: add configfs support

Add support for using the sourcesink 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>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/usb/gadget/f_sourcesink.c b/drivers/usb/gadget/f_sourcesink.c
index c5ad4a1fa3c..5d4251e7a37 100644
--- a/drivers/usb/gadget/f_sourcesink.c
+++ b/drivers/usb/gadget/f_sourcesink.c
@@ -477,6 +477,14 @@ no_iso:
 static void
 sourcesink_free_func(struct usb_function *f)
 {
+	struct f_ss_opts *opts;
+
+	opts = container_of(f->fi, struct f_ss_opts, func_inst);
+
+	mutex_lock(&opts->lock);
+	opts->refcnt--;
+	mutex_unlock(&opts->lock);
+
 	usb_free_all_descriptors(f);
 	kfree(func_to_ss(f));
 }
@@ -865,6 +873,11 @@ static struct usb_function *source_sink_alloc_func(
 		return NULL;
 
 	ss_opts =  container_of(fi, struct f_ss_opts, func_inst);
+
+	mutex_lock(&ss_opts->lock);
+	ss_opts->refcnt++;
+	mutex_unlock(&ss_opts->lock);
+
 	pattern = ss_opts->pattern;
 	isoc_interval = ss_opts->isoc_interval;
 	isoc_maxpacket = ss_opts->isoc_maxpacket;
@@ -885,6 +898,303 @@ static struct usb_function *source_sink_alloc_func(
 	return &ss->function;
 }
 
+static inline struct f_ss_opts *to_f_ss_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_ss_opts,
+			    func_inst.group);
+}
+
+CONFIGFS_ATTR_STRUCT(f_ss_opts);
+CONFIGFS_ATTR_OPS(f_ss_opts);
+
+static void ss_attr_release(struct config_item *item)
+{
+	struct f_ss_opts *ss_opts = to_f_ss_opts(item);
+
+	usb_put_function_instance(&ss_opts->func_inst);
+}
+
+static struct configfs_item_operations ss_item_ops = {
+	.release		= ss_attr_release,
+	.show_attribute		= f_ss_opts_attr_show,
+	.store_attribute	= f_ss_opts_attr_store,
+};
+
+static ssize_t f_ss_opts_pattern_show(struct f_ss_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%d", opts->pattern);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_ss_opts_pattern_store(struct f_ss_opts *opts,
+				       const char *page, size_t len)
+{
+	int ret;
+	u8 num;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	ret = kstrtou8(page, 0, &num);
+	if (ret)
+		goto end;
+
+	if (num != 0 && num != 1 && num != 2) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	opts->pattern = num;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_ss_opts_attribute f_ss_opts_pattern =
+	__CONFIGFS_ATTR(pattern, S_IRUGO | S_IWUSR,
+			f_ss_opts_pattern_show,
+			f_ss_opts_pattern_store);
+
+static ssize_t f_ss_opts_isoc_interval_show(struct f_ss_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%d", opts->isoc_interval);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_ss_opts_isoc_interval_store(struct f_ss_opts *opts,
+				       const char *page, size_t len)
+{
+	int ret;
+	u8 num;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	ret = kstrtou8(page, 0, &num);
+	if (ret)
+		goto end;
+
+	if (num > 16) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	opts->isoc_interval = num;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_ss_opts_attribute f_ss_opts_isoc_interval =
+	__CONFIGFS_ATTR(isoc_interval, S_IRUGO | S_IWUSR,
+			f_ss_opts_isoc_interval_show,
+			f_ss_opts_isoc_interval_store);
+
+static ssize_t f_ss_opts_isoc_maxpacket_show(struct f_ss_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%d", opts->isoc_maxpacket);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_ss_opts_isoc_maxpacket_store(struct f_ss_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 > 1024) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	opts->isoc_maxpacket = num;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_ss_opts_attribute f_ss_opts_isoc_maxpacket =
+	__CONFIGFS_ATTR(isoc_maxpacket, S_IRUGO | S_IWUSR,
+			f_ss_opts_isoc_maxpacket_show,
+			f_ss_opts_isoc_maxpacket_store);
+
+static ssize_t f_ss_opts_isoc_mult_show(struct f_ss_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%d", opts->isoc_mult);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_ss_opts_isoc_mult_store(struct f_ss_opts *opts,
+				       const char *page, size_t len)
+{
+	int ret;
+	u8 num;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	ret = kstrtou8(page, 0, &num);
+	if (ret)
+		goto end;
+
+	if (num > 2) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	opts->isoc_mult = num;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_ss_opts_attribute f_ss_opts_isoc_mult =
+	__CONFIGFS_ATTR(isoc_mult, S_IRUGO | S_IWUSR,
+			f_ss_opts_isoc_mult_show,
+			f_ss_opts_isoc_mult_store);
+
+static ssize_t f_ss_opts_isoc_maxburst_show(struct f_ss_opts *opts, char *page)
+{
+	int result;
+
+	mutex_lock(&opts->lock);
+	result = sprintf(page, "%d", opts->isoc_maxburst);
+	mutex_unlock(&opts->lock);
+
+	return result;
+}
+
+static ssize_t f_ss_opts_isoc_maxburst_store(struct f_ss_opts *opts,
+				       const char *page, size_t len)
+{
+	int ret;
+	u8 num;
+
+	mutex_lock(&opts->lock);
+	if (opts->refcnt) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	ret = kstrtou8(page, 0, &num);
+	if (ret)
+		goto end;
+
+	if (num > 15) {
+		ret = -EINVAL;
+		goto end;
+	}
+
+	opts->isoc_maxburst = num;
+	ret = len;
+end:
+	mutex_unlock(&opts->lock);
+	return ret;
+}
+
+static struct f_ss_opts_attribute f_ss_opts_isoc_maxburst =
+	__CONFIGFS_ATTR(isoc_maxburst, S_IRUGO | S_IWUSR,
+			f_ss_opts_isoc_maxburst_show,
+			f_ss_opts_isoc_maxburst_store);
+
+static ssize_t f_ss_opts_bulk_buflen_show(struct f_ss_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_ss_opts_bulk_buflen_store(struct f_ss_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_ss_opts_attribute f_ss_opts_bulk_buflen =
+	__CONFIGFS_ATTR(buflen, S_IRUGO | S_IWUSR,
+			f_ss_opts_bulk_buflen_show,
+			f_ss_opts_bulk_buflen_store);
+
+static struct configfs_attribute *ss_attrs[] = {
+	&f_ss_opts_pattern.attr,
+	&f_ss_opts_isoc_interval.attr,
+	&f_ss_opts_isoc_maxpacket.attr,
+	&f_ss_opts_isoc_mult.attr,
+	&f_ss_opts_isoc_maxburst.attr,
+	&f_ss_opts_bulk_buflen.attr,
+	NULL,
+};
+
+static struct config_item_type ss_func_type = {
+	.ct_item_ops    = &ss_item_ops,
+	.ct_attrs	= ss_attrs,
+	.ct_owner       = THIS_MODULE,
+};
+
 static void source_sink_free_instance(struct usb_function_instance *fi)
 {
 	struct f_ss_opts *ss_opts;
@@ -900,7 +1210,15 @@ static struct usb_function_instance *source_sink_alloc_inst(void)
 	ss_opts = kzalloc(sizeof(*ss_opts), GFP_KERNEL);
 	if (!ss_opts)
 		return ERR_PTR(-ENOMEM);
+	mutex_init(&ss_opts->lock);
 	ss_opts->func_inst.free_func_inst = source_sink_free_instance;
+	ss_opts->isoc_interval = GZERO_ISOC_INTERVAL;
+	ss_opts->isoc_maxpacket = GZERO_ISOC_MAXPACKET;
+	ss_opts->bulk_buflen = GZERO_BULK_BUFLEN;
+
+	config_group_init_type_name(&ss_opts->func_inst.group, "",
+				    &ss_func_type);
+
 	return &ss_opts->func_inst;
 }
 DECLARE_USB_FUNCTION(SourceSink, source_sink_alloc_inst,