Bluetooth: Add initial packet sending support to Three-wire UART
This patch adds initial packed encoding and sending support to the
Three-wire UART HCI transport driver.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index ddf7ebb..6df4c07 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -30,6 +30,9 @@
#include "hci_uart.h"
+#define HCI_3WIRE_ACK_PKT 0
+#define HCI_3WIRE_LINK_PKT 15
+
#define H5_TXWINSIZE 4
#define H5_ACK_TIMEOUT msecs_to_jiffies(250)
@@ -60,7 +63,8 @@
bool txack_req;
- u8 msgq_txseq;
+ u8 next_ack;
+ u8 next_seq;
};
static void h5_reset_rx(struct h5 *h5);
@@ -77,7 +81,7 @@
spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
- h5->msgq_txseq = (h5->msgq_txseq - 1) & 0x07;
+ h5->next_seq = (h5->next_seq - 1) & 0x07;
skb_queue_head(&h5->rel, skb);
}
@@ -355,10 +359,96 @@
return 0;
}
-static struct sk_buff *h5_prepare_pkt(struct h5 *h5, struct sk_buff *skb)
+static void h5_slip_delim(struct sk_buff *skb)
{
+ const char delim = SLIP_DELIMITER;
+
+ memcpy(skb_put(skb, 1), &delim, 1);
+}
+
+static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
+{
+ const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
+ const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
+
+ switch (c) {
+ case SLIP_DELIMITER:
+ memcpy(skb_put(skb, 2), &esc_delim, 2);
+ break;
+ case SLIP_ESC:
+ memcpy(skb_put(skb, 2), &esc_esc, 2);
+ break;
+ default:
+ memcpy(skb_put(skb, 1), &c, 1);
+ }
+}
+
+static struct sk_buff *h5_build_pkt(struct h5 *h5, bool rel, u8 pkt_type,
+ const u8 *data, size_t len)
+{
+ struct sk_buff *nskb;
+ u8 hdr[4];
+ int i;
+
+ /*
+ * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
+ * (because bytes 0xc0 and 0xdb are escaped, worst case is when
+ * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
+ * delimiters at start and end).
+ */
+ nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
+ if (!nskb)
+ return NULL;
+
+ bt_cb(nskb)->pkt_type = pkt_type;
+
+ h5_slip_delim(nskb);
+
+ hdr[0] = h5->next_ack << 3;
h5->txack_req = false;
- return NULL;
+
+ if (rel) {
+ hdr[0] |= 1 << 7;
+ hdr[0] |= h5->next_seq;
+ h5->next_seq = (h5->next_seq + 1) % 8;
+ }
+
+ hdr[1] = pkt_type | ((len & 0x0f) << 4);
+ hdr[2] = len >> 4;
+ hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
+
+ for (i = 0; i < 4; i++)
+ h5_slip_one_byte(nskb, hdr[i]);
+
+ for (i = 0; i < len; i++)
+ h5_slip_one_byte(nskb, data[i]);
+
+ h5_slip_delim(nskb);
+
+ return nskb;
+}
+
+static struct sk_buff *h5_prepare_pkt(struct h5 *h5, u8 pkt_type,
+ const u8 *data, size_t len)
+{
+ bool rel;
+
+ switch (pkt_type) {
+ case HCI_ACLDATA_PKT:
+ case HCI_COMMAND_PKT:
+ rel = true;
+ break;
+ case HCI_SCODATA_PKT:
+ case HCI_3WIRE_LINK_PKT:
+ case HCI_3WIRE_ACK_PKT:
+ rel = false;
+ break;
+ default:
+ BT_ERR("Unknown packet type %u", pkt_type);
+ return NULL;
+ }
+
+ return h5_build_pkt(h5, rel, pkt_type, data, len);
}
static struct sk_buff *h5_prepare_ack(struct h5 *h5)
@@ -374,7 +464,8 @@
struct sk_buff *skb, *nskb;
if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
- nskb = h5_prepare_pkt(h5, skb);
+ nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type,
+ skb->data, skb->len);
if (nskb) {
kfree_skb(skb);
return nskb;
@@ -390,8 +481,8 @@
goto unlock;
if ((skb = skb_dequeue(&h5->rel)) != NULL) {
- nskb = h5_prepare_pkt(h5, skb);
-
+ nskb = h5_prepare_pkt(h5, bt_cb(skb)->pkt_type,
+ skb->data, skb->len);
if (nskb) {
__skb_queue_tail(&h5->unack, skb);
mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);