[ncm] Add support for CDC-NCM USB Ethernet devices

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 186 insertions, 0 deletions

diff --git a/src/drivers/net/ncm.h b/src/drivers/net/ncm.h
new file mode 100644
index 00000000..5f02b49e
--- /dev/null
+++ b/src/drivers/net/ncm.h
@@ -0,0 +1,186 @@
+#ifndef _NCM_H
+#define _NCM_H
+
+/** @file
+ *
+ * CDC-NCM USB Ethernet driver
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/usb.h>
+#include <ipxe/cdc.h>
+#include <byteswap.h>
+#include "ecm.h"
+
+/** CDC-NCM subclass */
+#define USB_SUBCLASS_CDC_NCM 0x0d
+
+/** CDC-NCM interfaces */
+enum ncm_interfaces {
+	/** Communications interface */
+	NCM_INTERFACE_COMMS = 0,
+	/** Data interface */
+	NCM_INTERFACE_DATA,
+	NCM_INTERFACE_COUNT
+};
+
+/** Alternate setting for CDC-NCM data interface */
+#define NCM_DATA_ALTERNATE 1
+
+/** Get NTB parameters */
+#define NCM_GET_NTB_PARAMETERS						\
+	( USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE |		\
+	  USB_REQUEST_TYPE ( 0x80 ) )
+
+/** NTB datagram parameters */
+struct ncm_ntb_datagram_parameters {
+	/** Maximum size */
+	uint32_t mtu;
+	/** Alignment divisor */
+	uint16_t divisor;
+	/** Alignment remainder */
+	uint16_t remainder;
+	/** Alignment modulus */
+	uint16_t modulus;
+} __attribute__ (( packed ));
+
+/** NTB parameters */
+struct ncm_ntb_parameters {
+	/** Length */
+	uint16_t len;
+	/** Supported formats */
+	uint16_t formats;
+	/** IN datagram parameters */
+	struct ncm_ntb_datagram_parameters in;
+	/** Reserved */
+	uint16_t reserved;
+	/** OUT datagram parameters */
+	struct ncm_ntb_datagram_parameters out;
+	/** Maximum number of datagrams per OUT NTB */
+	uint16_t max;
+} __attribute__ (( packed ));
+
+/** Set NTB input size */
+#define NCM_SET_NTB_INPUT_SIZE						\
+	( USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE |		\
+	  USB_REQUEST_TYPE ( 0x86 ) )
+
+/** Set NTB input size */
+struct ncm_set_ntb_input_size {
+	/** Maximum size */
+	uint32_t mtu;
+} __attribute__ (( packed ));
+
+/** NTB input size
+ *
+ * This is a policy decision.  2048 is the minimum size which must be
+ * supported according to the specification.
+ */
+#define NCM_NTB_INPUT_SIZE 2048
+
+/** CDC-NCM transfer header (16-bit) */
+struct ncm_transfer_header {
+	/** Signature */
+	uint32_t magic;
+	/** Header length */
+	uint16_t header_len;
+	/** Sequence number */
+	uint16_t sequence;
+	/** Total length */
+	uint16_t len;
+	/** Offset of first datagram pointer */
+	uint16_t offset;
+} __attribute__ (( packed ));
+
+/** CDC-NCM transfer header magic */
+#define NCM_TRANSFER_HEADER_MAGIC 0x484d434eUL
+
+/** CDC-NCM datagram descriptor (16-bit) */
+struct ncm_datagram_descriptor {
+	/** Starting offset */
+	uint16_t offset;
+	/** Length */
+	uint16_t len;
+} __attribute__ (( packed ));
+
+/** CDC-NCM datagram pointer (16-bit) */
+struct ncm_datagram_pointer {
+	/** Signature */
+	uint32_t magic;
+	/** Header length */
+	uint16_t header_len;
+	/** Offset of next datagram pointer */
+	uint16_t offset;
+	/** Datagram descriptors
+	 *
+	 * Must be terminated by an empty descriptor.
+	 */
+	struct ncm_datagram_descriptor desc[0];
+} __attribute__ (( packed ));
+
+/** CDC-NCM datagram pointer magic */
+#define NCM_DATAGRAM_POINTER_MAGIC 0x304d434eUL
+
+/** CDC-NCM datagram pointer CRC present flag */
+#define NCM_DATAGRAM_POINTER_MAGIC_CRC 0x01000000UL
+
+/** NTB constructed for transmitted packets (excluding padding)
+ *
+ * This is a policy decision.
+ */
+struct ncm_ntb_header {
+	/** Transfer header */
+	struct ncm_transfer_header nth;
+	/** Datagram pointer */
+	struct ncm_datagram_pointer ndp;
+	/** Datagram descriptors */
+	struct ncm_datagram_descriptor desc[2];
+} __attribute__ (( packed ));
+
+/** A CDC-NCM network device */
+struct ncm_device {
+	/** USB device */
+	struct usb_device *usb;
+	/** USB bus */
+	struct usb_bus *bus;
+	/** Network device */
+	struct net_device *netdev;
+
+	/** Communications interface */
+	unsigned int comms;
+	/** Data interface */
+	unsigned int data;
+
+	/** Interrupt endpoint */
+	struct usb_endpoint intr;
+	/** Bulk IN endpoint */
+	struct usb_endpoint in;
+	/** Bulk OUT endpoint */
+	struct usb_endpoint out;
+
+	/** Recycled interrupt I/O buffers */
+	struct list_head intrs;
+	/** Current bulk IN ring fill level */
+	unsigned int fill;
+	/** Transmitted packet sequence number */
+	uint16_t sequence;
+	/** Alignment padding required on transmitted packets */
+	size_t padding;
+};
+
+/** Bulk IN ring fill level
+ *
+ * This is a policy decision.
+ */
+#define NCM_IN_FILL 16
+
+/** Interrupt ring fill level
+ *
+ * This is a policy decision.
+ */
+#define NCM_INTR_FILL 2
+
+#endif /* _NCM_H */