Bluetooth: nble: Implement bt_enable

Resets Nordic BLE chip and opens communication channel to UART.

Change-Id: Ie516869a4d978fc1622361ebc42894430fdf9ea6
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

drivers/nble/Kconfig

@@ -37,6 +37,11 @@ config	BLUETOOTH_MAX_PAIRED
 	int
 	default 7
 
+config BLUETOOTH_DEBUG
+	bool
+	default n
+	select STDOUT_CONSOLE
+
 config  NBLE_UART_ON_DEV_NAME
 	string "Device Name of UART Device for Nordic BLE"
 	default "UART_0"
@@ -66,7 +71,9 @@ config NBLE
 	select BLUETOOTH_CENTRAL
 	select BLUETOOTH_GATT_CLIENT
 	select BLUETOOTH_SMP
+	select BLUETOOTH_DEBUG
 	select UART_INTERRUPT_DRIVEN
+	select NANO_TIMEOUTS
 	select NET_BUF
 	help
 	  Enables support for using Nordic Semiconductor nRF51 Bluetooth

drivers/nble/gap.c

@@ -16,12 +16,122 @@
 
 #include <errno.h>
 
+#include <nanokernel.h>
+#include <device.h>
+#include <gpio.h>
+
 #include <bluetooth/bluetooth.h>
 #include <bluetooth/conn.h>
+#include <bluetooth/log.h>
+
+#include "uart.h"
+
+#define NBLE_SWDIO_PIN	6
+#define NBLE_RESET_PIN	NBLE_SWDIO_PIN
+
+#define NBLE_CHANNEL	0
+
+static void *channel;
+
+/**
+ * Function handling the events from the UART IPC (irq).
+ *
+ * @param channel Channel on which the event applies
+ * @param request IPC_MSG_TYPE_MESSAGE when a new message was received,
+ * IPC_MSG_TYPE_FREE when the previous message was sent and can be freed.
+ * @param len Length of the data
+ * @param p_data Pointer to the data
+ * @return 0
+ */
+static int recv_cb(int channel, int request, int len, void *p_data)
+{
+	BT_DBG("channel %d request %d len %d", channel, request, len);
+
+	switch (request) {
+	case IPC_MSG_TYPE_MESSAGE:
+		break;
+	case IPC_MSG_TYPE_FREE:
+		/* TODO: Try to send another message immediately */
+		break;
+	default:
+		/* Free the message */
+		BT_ERR("Unsupported RPC request");
+		break;
+	}
+
+	return 0;
+}
 
 int bt_enable(bt_ready_cb_t cb)
 {
-	return -ENOSYS;
+	struct device *gpio;
+	int ret;
+
+	BT_DBG("");
+
+	gpio = device_get_binding(CONFIG_GPIO_DW_0_NAME);
+	if (!gpio) {
+		BT_ERR("Cannot find %", CONFIG_GPIO_DW_0_NAME);
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure(gpio, NBLE_RESET_PIN, GPIO_DIR_OUT);
+	if (ret) {
+		BT_ERR("Error configuring pin %d", NBLE_RESET_PIN);
+		return -ENODEV;
+	}
+
+	/* Reset hold time is 0.2us (normal) or 100us (SWD debug) */
+	ret = gpio_pin_write(gpio, NBLE_RESET_PIN, 0);
+	if (ret) {
+		BT_ERR("Error pin write %d", NBLE_RESET_PIN);
+		return -EINVAL;
+	}
+
+	/**
+	 * NBLE reset is achieved by asserting low the SWDIO pin.
+	 * However, the BLE Core chip can be in SWD debug mode,
+	 * and NRF_POWER->RESET = 0 due to, other constraints: therefore,
+	 * this reset might not work everytime, especially after
+	 * flashing or debugging.
+	 */
+
+	/* sleep 1ms depending on context */
+	switch (sys_execution_context_type_get()) {
+	case NANO_CTX_FIBER:
+		fiber_sleep(MSEC(1));
+		break;
+	case NANO_CTX_TASK:
+		task_sleep(MSEC(1));
+		break;
+	default:
+		BT_ERR("ISR context is not supported");
+		return -EINVAL;
+	}
+
+	/* Open the UART channel for RPC while Nordic is in reset */
+	channel = ipc_uart_channel_open(NBLE_CHANNEL, recv_cb);
+	BT_DBG("channel %p", channel);
+
+	ret = nble_open();
+	if (ret) {
+		return ret;
+	}
+
+	ret = gpio_pin_write(gpio, NBLE_RESET_PIN, 1);
+	if (ret) {
+		BT_ERR("Error pin write %d", NBLE_RESET_PIN);
+		return -EINVAL;
+	}
+
+	/* Set back GPIO to input to avoid interfering with external debugger */
+	ret = gpio_pin_configure(gpio, NBLE_RESET_PIN, GPIO_DIR_IN);
+	if (ret) {
+		BT_ERR("Error configuring pin %d", NBLE_RESET_PIN);
+		return -ENODEV;
+	}
+
+	return 0;
 }
 
 int bt_le_adv_start(const struct bt_le_adv_param *param,

drivers/nble/uart.h

@@ -54,6 +54,7 @@ struct ipc_uart_channels {
 
 void ipc_uart_isr(void);
 void ipc_uart_ns16550_disable(struct device *dev);
+int nble_open(void);
 
 /**
  * This function triggers the sending of PDU buffer over UART.