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, 108 insertions, 0 deletions

diff --git a/net/caif/cfdgml.c b/net/caif/cfdgml.c
new file mode 100644
index 000000000000..53194840ecb6
--- /dev/null
+++ b/net/caif/cfdgml.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.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 DGM_CMD_BIT  0x80
+#define DGM_FLOW_OFF 0x81
+#define DGM_FLOW_ON  0x80
+#define DGM_CTRL_PKT_SIZE 1
+
+static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
+{
+        struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+        if (!dgm) {
+                pr_warning("CAIF: %s(): Out of memory\n", __func__);
+                return NULL;
+        }
+        caif_assert(offsetof(struct cfsrvl, layer) == 0);
+        memset(dgm, 0, sizeof(struct cfsrvl));
+        cfsrvl_init(dgm, channel_id, dev_info);
+        dgm->layer.receive = cfdgml_receive;
+        dgm->layer.transmit = cfdgml_transmit;
+        snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
+        dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
+        return &dgm->layer;
+}
+
+static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+        u8 cmd = -1;
+        u8 dgmhdr[3];
+        int ret;
+        caif_assert(layr->up != NULL);
+        caif_assert(layr->receive != NULL);
+        caif_assert(layr->ctrlcmd != NULL);
+
+        if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
+                pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
+                cfpkt_destroy(pkt);
+                return -EPROTO;
+        }
+
+        if ((cmd & DGM_CMD_BIT) == 0) {
+                if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
+                        pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
+                        cfpkt_destroy(pkt);
+                        return -EPROTO;
+                }
+                ret = layr->up->receive(layr->up, pkt);
+                return ret;
+        }
+
+        switch (cmd) {
+        case DGM_FLOW_OFF:      /* FLOW OFF */
+                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
+                cfpkt_destroy(pkt);
+                return 0;
+        case DGM_FLOW_ON:       /* FLOW ON */
+                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
+                cfpkt_destroy(pkt);
+                return 0;
+        default:
+                cfpkt_destroy(pkt);
+                pr_info("CAIF: %s(): Unknown datagram control %d (0x%x)\n",
+                        __func__, cmd, cmd);
+                return -EPROTO;
+        }
+}
+
+static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+        u32 zero = 0;
+        struct caif_payload_info *info;
+        struct cfsrvl *service = container_obj(layr);
+        int ret;
+        if (!cfsrvl_ready(service, &ret))
+                return ret;
+
+        cfpkt_add_head(pkt, &zero, 4);
+
+        /* 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 = 4;
+        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;
+}