From 9632d46ae793765ea948061b93945da5fa3d89db Mon Sep 17 00:00:00 2001
From: Johan Hedberg <johan.hedberg@intel.com>
Date: Thu, 11 Feb 2016 11:35:03 +0200
Subject: [PATCH] drivers/nble: Clean up & simplify IPC UART encoding

We can take advantage of the net_buf headroom. At the same time move
the necessary definition straight into uart.c and remove any unused
definitions.

Change-Id: I932bba2cfb11808aabce7bad09e41f94d073bb5b
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
---
 drivers/nble/uart.c | 38 +++++++++++++++++++-------------------
 drivers/nble/uart.h | 31 -------------------------------
 2 files changed, 19 insertions(+), 50 deletions(-)

diff --git a/drivers/nble/uart.c b/drivers/nble/uart.c
index 447992f9f0d..9f9b7c83d5a 100644
--- a/drivers/nble/uart.c
+++ b/drivers/nble/uart.c
@@ -31,6 +31,15 @@
 #include "uart.h"
 #include "rpc.h"
 
+/**
+ * @note this structure must be self-aligned and self-packed
+ */
+struct ipc_uart_header {
+	uint16_t len;		/**< Length of IPC message. */
+	uint8_t channel;	/**< Channel number of IPC message. */
+	uint8_t src_cpu_id;	/**< CPU id of IPC sender. */
+} __packed;
+
 /* TODO: check size */
 #define NBLE_TX_BUF_COUNT	2
 #define NBLE_RX_BUF_COUNT	8
@@ -70,7 +79,7 @@ struct net_buf *rpc_alloc_cb(uint16_t length)
 
 	BT_DBG("length %u", length);
 
-	buf = net_buf_get(&tx, 0);
+	buf = net_buf_get(&tx, sizeof(struct ipc_uart_header));
 	if (!buf) {
 		BT_ERR("Unable to get tx buffer");
 		return NULL;
@@ -85,30 +94,21 @@ struct net_buf *rpc_alloc_cb(uint16_t length)
 	return buf;
 }
 
-static void poll_out(const void *buf, size_t length)
-{
-	const uint8_t *ptr = buf;
-
-	while (length--) {
-		uart_poll_out(nble_dev, *ptr++);
-	}
-}
-
 void rpc_transmit_cb(struct net_buf *buf)
 {
-	struct ipc_uart_header hdr;
+	struct ipc_uart_header *hdr;
 
 	BT_DBG("buf %p length %u", buf, buf->len);
 
-	hdr.len = buf->len;
-	hdr.channel = 0;
-	hdr.src_cpu_id = 0;
+	hdr = net_buf_push(buf, sizeof(*hdr));
+	hdr->len = buf->len - sizeof(*hdr);
+	hdr->channel = 0;
+	hdr->src_cpu_id = 0;
 
-	/* Send header */
-	poll_out(&hdr, sizeof(hdr));
-
-	/* Send data */
-	poll_out(buf->data, buf->len);
+	while (buf->len) {
+		uart_poll_out(nble_dev, buf->data[0]);
+		net_buf_pull(buf, 1);
+	}
 
 	net_buf_unref(buf);
 }
diff --git a/drivers/nble/uart.h b/drivers/nble/uart.h
index 346072bafbb..d4e5a7fc5a7 100644
--- a/drivers/nble/uart.h
+++ b/drivers/nble/uart.h
@@ -21,37 +21,6 @@
  */
 extern struct driver ipc_uart_ns16550_driver;
 
-enum IPC_UART_RESULT_CODES {
-	IPC_UART_ERROR_OK = 0,
-	IPC_UART_ERROR_DATA_TO_BIG,
-	/**< A transmission is already ongoing, message is NOT sent */
-	IPC_UART_TX_BUSY
-};
-
-/**
- * Definitions valid for NONE sync IPC UART headers.
- */
-
-/**
- * @note this structure must be self-aligned and self-packed
- */
-struct ipc_uart_header {
-	uint16_t len;		/**< Length of IPC message. */
-	uint8_t channel;	/**< Channel number of IPC message. */
-	uint8_t src_cpu_id;	/**< CPU id of IPC sender. */
-};
-
-#define IPC_CHANNEL_STATE_CLOSED	0
-#define IPC_CHANNEL_STATE_OPEN		1
-
-#define IPC_UART_MAX_CHANNEL		1
-
-struct ipc_uart_channels {
-	uint16_t index;
-	uint16_t state;
-	int (*cb)(int chan, int request, int len, void *data);
-};
-
 int nble_open(void);
 
 /**