net-caif: add CAIF core protocol stack

CAIF generic protocol implementation. This layer is
somewhat generic in order to be able to use and test it outside
the Linux Kernel.

cfctrl.c     - CAIF control protocol layer
cfdbgl.c     - CAIF debug protocol layer
cfdgml.c     - CAIF datagram protocol layer
cffrml.c     - CAIF framing protocol layer
cfmuxl.c     - CAIF mux protocol layer
cfrfml.c     - CAIF remote file manager protocol layer
cfserl.c     - CAIF serial (fragmentation) protocol layer
cfsrvl.c     - CAIF generic service layer functions
cfutill.c    - CAIF utility protocol layer
cfveil.c     - CAIF AT protocol layer
cfvidl.c     - CAIF video protocol layer

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 115 insertions, 0 deletions

diff --git a/net/caif/cfutill.c b/net/caif/cfutill.c
new file mode 100644
index 0000000..5fd2c9e
--- /dev/null
+++ b/net/caif/cfutill.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) ((struct cfsrvl *) layr)
+#define UTIL_PAYLOAD  0x00
+#define UTIL_CMD_BIT  0x80
+#define UTIL_REMOTE_SHUTDOWN 0x82
+#define UTIL_FLOW_OFF 0x81
+#define UTIL_FLOW_ON  0x80
+#define UTIL_CTRL_PKT_SIZE 1
+static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *util = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!util) {
+		pr_warning("CAIF: %s(): Out of memory\n", __func__);
+		return NULL;
+	}
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	memset(util, 0, sizeof(struct cfsrvl));
+	cfsrvl_init(util, channel_id, dev_info);
+	util->layer.receive = cfutill_receive;
+	util->layer.transmit = cfutill_transmit;
+	snprintf(util->layer.name, CAIF_LAYER_NAME_SZ - 1, "util1");
+	return &util->layer;
+}
+
+static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 cmd = -1;
+	struct cfsrvl *service = container_obj(layr);
+	caif_assert(layr != NULL);
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->up->receive != NULL);
+	caif_assert(layr->up->ctrlcmd != NULL);
+	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
+		pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	switch (cmd) {
+	case UTIL_PAYLOAD:
+		return layr->up->receive(layr->up, pkt);
+	case UTIL_FLOW_OFF:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case UTIL_FLOW_ON:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case UTIL_REMOTE_SHUTDOWN:	/* Remote Shutdown Request */
+		pr_err("CAIF: %s(): REMOTE SHUTDOWN REQUEST RECEIVED\n",
+			__func__);
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
+		service->open = false;
+		cfpkt_destroy(pkt);
+		return 0;
+	default:
+		cfpkt_destroy(pkt);
+		pr_warning("CAIF: %s(): Unknown service control %d (0x%x)\n",
+			   __func__, cmd, cmd);
+		return -EPROTO;
+	}
+}
+
+static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 zero = 0;
+	struct caif_payload_info *info;
+	int ret;
+	struct cfsrvl *service = container_obj(layr);
+	caif_assert(layr != NULL);
+	caif_assert(layr->dn != NULL);
+	caif_assert(layr->dn->transmit != NULL);
+	if (!cfsrvl_ready(service, &ret))
+		return ret;
+
+	if (cfpkt_getlen(pkt) > CAIF_MAX_PAYLOAD_SIZE) {
+		pr_err("CAIF: %s(): packet too large size=%d\n",
+			__func__, cfpkt_getlen(pkt));
+		return -EOVERFLOW;
+	}
+
+	cfpkt_add_head(pkt, &zero, 1);
+	/* Add info for MUX-layer to route the packet out. */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	/*
+	 * To optimize alignment, we add up the size of CAIF header before
+	 * payload.
+	 */
+	info->hdr_len = 1;
+	info->dev_info = &service->dev_info;
+	ret = layr->dn->transmit(layr->dn, pkt);
+	if (ret < 0) {
+		u32 tmp32;
+		cfpkt_extr_head(pkt, &tmp32, 4);
+	}
+	return ret;
+}