Some controllers support scatter/gather transfers
and that might be very useful for some gadget drivers.
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
include/linux/usb/gadget.h | 70 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 70 insertions(+), 0 deletions(-)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 22c37d2..fd61375 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -20,6 +20,7 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
+#include <linux/scatterlist.h>
#include <linux/types.h>
#include <linux/usb/ch9.h>
@@ -32,6 +33,8 @@ struct usb_ep;
* @dma: DMA address corresponding to 'buf'. If you don't set this
* field, and the usb controller needs one, it is responsible
* for mapping and unmapping the buffer.
+ * @sg: a scatterlist for SG-capable controllers.
+ * @num_sgs: number of SG entries
* @length: Length of that data
* @stream_id: The stream id, when USB3.0 bulk streams are being used
* @no_interrupt: If true, hints that no completion irq is needed.
@@ -88,6 +91,9 @@ struct usb_request {
unsigned length;
dma_addr_t dma;
+ struct scatterlist *sg;
+ unsigned num_sgs;
+
unsigned stream_id:16;
unsigned no_interrupt:1;
unsigned zero:1;
@@ -102,6 +108,22 @@ struct usb_request {
unsigned actual;
};
+struct usb_request_sg {
+ int status;
+ unsigned actual;
+
+ void (*complete)(struct usb_ep *ep,
+ struct usb_request_sg *rsg);
+ void *context;
+
+ /*
+ * Members below are private to the controller. Gadget
+ * drivers should not touch them.
+ */
+ struct usb_request **requests;
+ int num_entries;
+};
+
/*-------------------------------------------------------------------------*/
/* endpoint-specific parts of the api to the usb controller hardware.
@@ -120,6 +142,13 @@ struct usb_ep_ops {
gfp_t gfp_flags);
void (*free_request) (struct usb_ep *ep, struct usb_request *req);
+ int (*sg_prepare)(struct usb_ep *ep, struct usb_request_sg *rsg,
+ struct scatterlist *sg, unsigned int num_entries,
+ unsigned int length, gfp_t gfp_flags);
+ int (*sg_queue)(struct usb_ep *ep, struct usb_request_sg *rsg,
+ gfp_t gfp_flags);
+ int (*sg_dequeue)(struct usb_ep *ep, struct usb_request_sg *rsg);
+
int (*queue) (struct usb_ep *ep, struct usb_request *req,
gfp_t gfp_flags);
int (*dequeue) (struct usb_ep *ep, struct usb_request *req);
@@ -250,6 +279,45 @@ static inline void usb_ep_free_request(struct usb_ep *ep,
}
/**
+ * usb_ep_sg_prepare - prepares a sg list to be queued to the endpoint
+ * @ep: the endpoint associated with the request
+ * @rsg: the SG request
+ * @sg: the scatterlist
+ * @num_entries: number of entries
+ * @length: total length of the SG transfer
+ * @gfp_flags: flags for memory allocations on this call
+ */
+static inline int usb_ep_sg_prepare(struct usb_ep *ep,
+ struct usb_request_sg *rsg, struct scatterlist *sg,
+ unsigned int num_entries, unsigned int length, gfp_t gfp_flags)
+{
+ return ep->ops->sg_prepare(ep, rsg, sg, num_entries, length, gfp_flags);
+}
+
+/**
+ * usb_ep_sg_queue - queue a sg list to the endpoint
+ * @ep: the endpoint associated with the request
+ * @rsg: the SG request
+ * @gfp_flags: flags for memory allocations on this call
+ */
+static inline int usb_ep_sg_queue(struct usb_ep *ep,
+ struct usb_request_sg *rsg, gfp_t gfp_flags)
+{
+ return ep->ops->sg_queue(ep, rsg, gfp_flags);
+}
+
+/**
+ * usb_ep_sg_dequeue - dequeues a sg ist from the endpoint
+ * @ep: the endpoint associated with the request
+ * @rsg: the SG request to the dequeued
+ */
+static inline int usb_ep_sg_dequeue(struct usb_ep *ep,
+ struct usb_request_sg *rsg)
+{
+ return ep->ops->sg_dequeue(ep, rsg);
+}
+
+/**
* usb_ep_queue - queues (submits) an I/O request to an endpoint.
* @ep:the endpoint associated with the request
* @req:the request being submitted
@@ -479,6 +547,7 @@ struct usb_gadget_ops {
* @speed: Speed of current connection to USB host.
* @max_speed: Maximal speed the UDC can handle. UDC must support this
* and all slower speeds.
+ * @sg_tablesize: largest number of sg list entries or 0.
* @is_otg: True if the USB device port uses a Mini-AB jack, so that the
* gadget driver must provide a USB OTG descriptor.
* @is_a_peripheral: False unless is_otg, the "A" end of a USB cable
@@ -519,6 +588,7 @@ struct usb_gadget {
struct list_head ep_list; /* of usb_ep */
enum usb_device_speed speed;
enum usb_device_speed max_speed;
+ unsigned sg_tablesize;
unsigned is_otg:1;
unsigned is_a_peripheral:1;
unsigned b_hnp_enable:1;
--
1.7.8.rc0
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