greybus: camera: Implement the capabilities operation

The operation queries the camera module for its capabilities. The
debugfs interface just prints a hex dump of the binary message.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@linaro.org>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
index d499ffdb786bdc23a044c126b4cc8fd8615dd90d..6042c681b8b6632b5f13bc4324146b921a242f00 100644 (file)
--- a/drivers/staging/greybus/camera.c
+++ b/drivers/staging/greybus/camera.c
@@ -156,6 +156,33 @@ static int gb_camera_set_power_mode(struct gb_camera *gcam, bool hs)
        return 0;
 }
 
+static int gb_camera_capabilities(struct gb_camera *gcam,
+                                 u8 *capabilities, size_t *size)
+{
+       struct gb_operation *op;
+       int ret;
+
+       op = gb_operation_create_flags(gcam->connection,
+                                      GB_CAMERA_TYPE_CAPABILITIES, 0, *size,
+                                      GB_OPERATION_FLAG_SHORT_RESPONSE,
+                                      GFP_KERNEL);
+       if (!op)
+               return -ENOMEM;
+
+       ret = gb_operation_request_send_sync(op);
+       if (ret) {
+               gcam_err(gcam, "failed to retrieve capabilities: %d\n", ret);
+               goto done;
+       }
+
+       memcpy(capabilities, op->response->payload, op->response->payload_size);
+       *size = op->response->payload_size;
+
+done:
+       gb_operation_put(op);
+       return ret;
+}
+
 struct ap_csi_config_request {
        __u8 csi_id;
        __u8 flags;
@@ -478,10 +505,41 @@ static int gb_camera_register_intf_ops(struct gb_camera *gcam)
 /* -----------------------------------------------------------------------------
  * DebugFS
  */
+
 static ssize_t gb_camera_debugfs_capabilities(struct gb_camera *gcam,
                char *buf, size_t len)
 {
-       return len;
+       struct gb_camera_debugfs_buffer *buffer =
+               &gcam->debugfs.buffers[GB_CAMERA_DEBUGFS_BUFFER_CAPABILITIES];
+       size_t size = 1024;
+       unsigned int i;
+       u8 *caps;
+       int ret;
+
+       caps = kmalloc(size, GFP_KERNEL);
+       if (!caps)
+               return -ENOMEM;
+
+       ret = gb_camera_capabilities(gcam, caps, &size);
+       if (ret < 0)
+               goto done;
+
+       /*
+        * hex_dump_to_buffer() doesn't return the number of bytes dumped prior
+        * to v4.0, we need our own implementation :-(
+        */
+       buffer->length = 0;
+
+       for (i = 0; i < size; i += 16) {
+               unsigned int nbytes = min_t(unsigned int, size - i, 16);
+
+               buffer->length += sprintf(buffer->data + buffer->length,
+                                         "%*ph\n", nbytes, caps + i);
+       }
+
+done:
+       kfree(caps);
+       return ret;
 }
 
 static ssize_t gb_camera_debugfs_configure_streams(struct gb_camera *gcam,