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/cfrfml.c b/net/caif/cfrfml.c
new file mode 100644
index 000000000000..cd2830fec935
--- /dev/null
+++ b/net/caif/cfrfml.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) container_of(layr, struct cfsrvl, layer)
+
+#define RFM_SEGMENTATION_BIT 0x01
+#define RFM_PAYLOAD  0x00
+#define RFM_CMD_BIT  0x80
+#define RFM_FLOW_OFF 0x81
+#define RFM_FLOW_ON  0x80
+#define RFM_SET_PIN  0x82
+#define RFM_CTRL_PKT_SIZE 1
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl);
+
+struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *rfm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!rfm) {
+		pr_warning("CAIF: %s(): Out of memory\n", __func__);
+		return NULL;
+	}
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	memset(rfm, 0, sizeof(struct cfsrvl));
+	cfsrvl_init(rfm, channel_id, dev_info);
+	rfm->layer.modemcmd = cfservl_modemcmd;
+	rfm->layer.receive = cfrfml_receive;
+	rfm->layer.transmit = cfrfml_transmit;
+	snprintf(rfm->layer.name, CAIF_LAYER_NAME_SZ, "rfm%d", channel_id);
+	return &rfm->layer;
+}
+
+static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
+{
+       return -EPROTO;
+}
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 tmp;
+	bool segmented;
+	int ret;
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->receive != NULL);
+
+	/*
+	 * RFM is taking care of segmentation and stripping of
+	 * segmentation bit.
+	 */
+	if (cfpkt_extr_head(pkt, &tmp, 1) < 0) {
+		pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+	segmented = tmp & RFM_SEGMENTATION_BIT;
+	caif_assert(!segmented);
+
+	ret = layr->up->receive(layr->up, pkt);
+	return ret;
+}
+
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 tmp = 0;
+	int ret;
+	struct cfsrvl *service = container_obj(layr);
+
+	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;
+	}
+	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
+		pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
+		return -EPROTO;
+	}
+
+	/* Add info for MUX-layer to route the packet out. */
+	cfpkt_info(pkt)->channel_id = service->layer.id;
+	/*
+	 * To optimize alignment, we add up the size of CAIF header before
+	 * payload.
+	 */
+	cfpkt_info(pkt)->hdr_len = 1;
+	cfpkt_info(pkt)->dev_info = &service->dev_info;
+	ret = layr->dn->transmit(layr->dn, pkt);
+	if (ret < 0)
+		cfpkt_extr_head(pkt, &tmp, 1);
+	return ret;
+}