can: rx-offload: Add support for HW fifo based irq offloading

Some CAN controllers have a usable FIFO already but can still benefit
from off-loading the CAN controller FIFO. The CAN frames of the FIFO are
read and put into a skb queue during interrupt and then transmitted in a
NAPI context.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 51 insertions, 0 deletions

diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h
new file mode 100644
index 000000000000..cadfe9869600
--- /dev/null
+++ b/include/linux/can/rx-offload.h
@@ -0,0 +1,51 @@
+/*
+ * linux/can/rx-offload.h
+ *
+ * Copyright (c) 2014 David Jander, Protonic Holland
+ * Copyright (c) 2014-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _CAN_RX_OFFLOAD_H
+#define _CAN_RX_OFFLOAD_H
+
+#include <linux/netdevice.h>
+#include <linux/can.h>
+
+struct can_rx_offload {
+        struct net_device *dev;
+
+        unsigned int (*mailbox_read)(struct can_rx_offload *offload, struct can_frame *cf, unsigned int mb);
+
+        struct sk_buff_head skb_queue;
+        u32 skb_queue_len_max;
+
+        struct napi_struct napi;
+};
+
+int can_rx_offload_add_fifo(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight);
+int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload);
+int can_rx_offload_irq_queue_err_skb(struct can_rx_offload *offload, struct sk_buff *skb);
+void can_rx_offload_reset(struct can_rx_offload *offload);
+void can_rx_offload_del(struct can_rx_offload *offload);
+void can_rx_offload_enable(struct can_rx_offload *offload);
+
+static inline void can_rx_offload_schedule(struct can_rx_offload *offload)
+{
+        napi_schedule(&offload->napi);
+}
+
+static inline void can_rx_offload_disable(struct can_rx_offload *offload)
+{
+        napi_disable(&offload->napi);
+}
+
+#endif /* !_CAN_RX_OFFLOAD_H */