Bluetooth: SPI: introduce CONFIG_BLUETOOTH_SPI_BLUENRG

This new option is used to encapsulate the logic specific to devices
implementing the BlueNRG Bluetooth stack (e.g. X-NUCLEO-IDB05A1).

The current BlueNRG specific logic covers the HCI Reset handling and
the manual control of the SPI Chip Select line (normally not needed since
spi_transceive is also responsible for controlling the SPI CS line).

Change-Id: I5db4addf873eee0af2d957e2181c50aac53ab656
Signed-off-by: Ricardo Salveti <ricardo.salveti@linaro.org>

drivers/bluetooth/hci/Kconfig

@@ -46,7 +46,7 @@ config BLUETOOTH_SPI
 	  HCI packets are sent and received as single Byte transferrs,
 	  prepended after a known header.  Headers may vary per device, so
 	  additional platform specific knowlege may need to be added as
-	  devices are.  Current driver supports; ST X-NUCLEO BLE series.
+	  devices are.
 
 config BLUETOOTH_NO_DRIVER
 	bool "No default HCI driver"
@@ -108,8 +108,16 @@ config BLUETOOTH_HCI_RECV_RESERVE
 
 if BLUETOOTH_SPI
 
+config BLUETOOTH_SPI_BLUENRG
+	bool "Enable compatibility with BlueNRG-based devices"
+	default n
+	help
+	  Enable support for devices compatible with the BlueNRG Bluetooth
+	  Stack. Current driver supports: ST X-NUCLEO BLE series.
+
 config BLUETOOTH_SPI_CHIP_SELECT_DEV_NAME
 	string "Chip Select (CS) line driver name"
+	depends on BLUETOOTH_SPI_BLUENRG
 	help
 	  This option specifies the name of GPIO driver controlling
 	  the Chip Select (CS) line.
@@ -128,6 +136,7 @@ config BLUETOOTH_SPI_RESET_DEV_NAME
 
 config BLUETOOTH_SPI_CHIP_SELECT_PIN
 	int "SPI Chip Select (CS) line number"
+	depends on BLUETOOTH_SPI_BLUENRG
 	help
 	  This option specifies the Chip Select (CS) line number on the SPI
 	  device

drivers/bluetooth/hci/spi.c

@@ -43,14 +43,18 @@
 #define CMD_OCF			2
 
 #define GPIO_IRQ_PIN		CONFIG_BLUETOOTH_SPI_IRQ_PIN
-#define GPIO_CS_PIN		CONFIG_BLUETOOTH_SPI_CHIP_SELECT_PIN
 #define GPIO_RESET_PIN		CONFIG_BLUETOOTH_SPI_RESET_PIN
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
+#define GPIO_CS_PIN		CONFIG_BLUETOOTH_SPI_CHIP_SELECT_PIN
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 
 #define MAX_RX_MSG_LEN		CONFIG_BLUETOOTH_SPI_RX_BUFFER_SIZE
 #define MAX_TX_MSG_LEN		CONFIG_BLUETOOTH_SPI_TX_BUFFER_SIZE
 
 static struct device		*spi_dev;
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 static struct device		*cs_dev;
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 static struct device		*irq_dev;
 static struct device		*rst_dev;
 
@@ -131,8 +135,10 @@ static void bt_spi_rx_thread(void)
 		k_sem_take(&sem_busy, K_FOREVER);
 
 		do {
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 			gpio_pin_write(cs_dev, GPIO_CS_PIN, 1);
 			gpio_pin_write(cs_dev, GPIO_CS_PIN, 0);
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 			spi_transceive(spi_dev,
 				       header_master, 5, header_slave, 5);
 		} while (header_slave[STATUS_HEADER_TOREAD] == 0 ||
@@ -144,7 +150,9 @@ static void bt_spi_rx_thread(void)
 			spi_transceive(spi_dev, &dummy, 1, &rxmsg[i], 1);
 		}
 
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 		gpio_pin_write(cs_dev, GPIO_CS_PIN, 1);
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 		k_sem_give(&sem_busy);
 
 		spi_dump_message("RX:ed", rxmsg, size);
@@ -221,8 +229,10 @@ static int bt_spi_send(struct net_buf *buf)
 
 	/* Poll sanity values until device has woken-up */
 	do {
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 		gpio_pin_write(cs_dev, GPIO_CS_PIN, 1);
 		gpio_pin_write(cs_dev, GPIO_CS_PIN, 0);
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 		spi_transceive(spi_dev, header, 5, rxmsg, 5);
 
 		/*
@@ -236,12 +246,15 @@ static int bt_spi_send(struct net_buf *buf)
 	/* Transmit the message */
 	spi_transceive(spi_dev, buf->data, buf->len, rxmsg, buf->len);
 
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 	/* Deselect chip */
 	gpio_pin_write(cs_dev, GPIO_CS_PIN, 1);
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 	k_sem_give(&sem_busy);
 
 	spi_dump_message("TX:ed", buf->data, buf->len);
 
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 	/*
 	 * Since a RESET has been requested, the chip will now restart.
 	 * Unfortunately the BlueNRG will reply with "reset received" but
@@ -252,6 +265,7 @@ static int bt_spi_send(struct net_buf *buf)
 	if (bt_spi_get_cmd(buf->data) == BT_HCI_OP_RESET) {
 		k_sem_take(&sem_initialised, K_FOREVER);
 	}
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 
 	net_buf_unref(buf);
 
@@ -267,10 +281,12 @@ static int bt_spi_open(void)
 
 	spi_configure(spi_dev, &spi_conf);
 
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 	/* Configure the CS (Chip Select) pin */
 	gpio_pin_configure(cs_dev, GPIO_CS_PIN,
 			   GPIO_DIR_OUT | GPIO_PUD_PULL_UP);
 	gpio_pin_write(cs_dev, GPIO_CS_PIN, 1);
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 
 	/* Configure IRQ pin and the IRQ call-back/handler */
 	gpio_pin_configure(irq_dev, GPIO_IRQ_PIN,
@@ -319,12 +335,14 @@ static int _bt_spi_init(struct device *unused)
 		return -EIO;
 	}
 
+#if defined(CONFIG_BLUETOOTH_SPI_BLUENRG)
 	cs_dev = device_get_binding(CONFIG_BLUETOOTH_SPI_CHIP_SELECT_DEV_NAME);
 	if (!cs_dev) {
 		BT_ERR("Failed to initialize GPIO driver: %s",
 		       CONFIG_BLUETOOTH_SPI_CHIP_SELECT_DEV_NAME);
 		return -EIO;
 	}
+#endif /* CONFIG_BLUETOOTH_SPI_BLUENRG */
 
 	irq_dev = device_get_binding(CONFIG_BLUETOOTH_SPI_IRQ_DEV_NAME);
 	if (!irq_dev) {