drivers/sx127x: Add support to different bitrate and RX timeout

drivers/wireless/lpwan/Kconfig

@@ -28,76 +28,6 @@ config LPWAN_SX127X
 	---help---
 		This options adds driver support for the Samtech SX127X chip.
 
-if LPWAN_SX127X
-
-config LPWAN_SX127X_RFFREQ_DEFAULT
-	int "SX127X default RF frequency"
-	default 433000000
-
-config LPWAN_SX127X_SPIFREQ
-	int "SX127X SPI frequency"
-	default 1000000
-	---help---
-		SX127X SPI frequency up to 10MHz
-
-config LPWAN_SX127X_TXPOWER_DEFAULT
-	int "SX127X default TX power"
-	default 14
-
-config LPWAN_SX127X_PREAMBLE_DEFAULT
-	int "SX127X default preamble length"
-	default 8
-
-config LPWAN_SX127X_MODULATION_DEFAULT
-	int "SX127X default modulation scheme"
-	default 3 if LPWAN_SX127X_LORA
-	default 1 if LPWAN_SX127X_FSKOOK
-	range 1 3
-	---help---
-		1 - FSK, 2 - OOK, 3 - LORA
-
-config LPWAN_SX127X_CRCON
-	int "SX127X CRC ON"
-	range 0 1
-	default 0
-
-config LPWAN_SX127X_RXSUPPORT
-	bool "SX127X RX support"
-	default n
-
-if LPWAN_SX127X_RXSUPPORT
-
-config LPWAN_SX127X_RXFIFO_LEN
-	int "SX127X RX FIFO length"
-	default 5
-
-config LPWAN_SX127X_RXFIFO_DATA_LEN
-	int "SX127X RX FIFO data length"
-	default 64
-
-endif #LPWAN_SX127X_RXSUPPORT
-
-config LPWAN_SX127X_TXSUPPORT
-	bool "SX127X TX support"
-	default n
-
-config LPWAN_SX127X_LORA
-	bool "SX127X LORA support"
-	default y
-
-if LPWAN_SX127X_LORA
-
-config LPWAN_SX127X_LORA_IMPHEADER
-	int "SX127X LORA implicit header ON"
-	range 0 1
-	default 0
-
-endif # LPWAN_SX127X_LORA
-
-config LPWAN_SX127X_FSKOOK
-	bool "SX127X FSK/OOK support"
-	default n
-
-endif # WL_SX127X
+source "drivers/wireless/lpwan/sx127x/Kconfig"
 
 endif # DRIVERS_LPWAN

drivers/wireless/lpwan/sx126x/Kconfig

@@ -25,4 +25,4 @@ config LPWAN_SX126X_MAX_DEVICES
 	int "SX126X maximum devices"
 	default 1
 
-endif # DRIVERS_LPWAN
+endif # LPWAN_SX126X

drivers/wireless/lpwan/sx127x/Kconfig

@@ -0,0 +1,107 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+if LPWAN_SX127X
+
+config LPWAN_SX127X_RFFREQ_DEFAULT
+	int "SX127X default RF frequency"
+	default 433000000
+
+config LPWAN_SX127X_SPIFREQ
+	int "SX127X SPI frequency"
+	default 1000000
+	---help---
+		SX127X SPI frequency up to 10MHz
+
+config LPWAN_SX127X_TXPOWER_DEFAULT
+	int "SX127X default TX power"
+	default 14
+
+config LPWAN_SX127X_PREAMBLE_DEFAULT
+	int "SX127X default preamble length"
+	default 8
+
+config LPWAN_SX127X_MODULATION_DEFAULT
+	int "SX127X default modulation scheme"
+	default 3 if LPWAN_SX127X_LORA
+	default 1 if LPWAN_SX127X_FSKOOK
+	range 1 3
+	---help---
+		1 - FSK, 2 - OOK, 3 - LORA
+
+config LPWAN_SX127X_CRCON
+	int "SX127X CRC ON"
+	range 0 1
+	default 0
+
+config LPWAN_SX127X_RXSUPPORT
+	bool "SX127X RX support"
+	default n
+
+if LPWAN_SX127X_RXSUPPORT
+
+config LPWAN_SX127X_RXFIFO_LEN
+	int "SX127X RX FIFO length"
+	default 5
+
+config LPWAN_SX127X_RXFIFO_DATA_LEN
+	int "SX127X RX FIFO data length"
+	default 64
+
+config LPWAN_SX127X_RX_TIMEOUT
+	int "SX127X RX Timeout in Milliseconds"
+	default 10000
+	---help---
+		If device stopped receiving data for more than
+		LPWAN_SX127X_RX_TIMEOUT milliseconds it means the
+		frequency drift is too high that AFC failed to fix
+		the reception frequency. So if we leave the RX mode,
+		entering in standby and returning will clear the
+		AFC and fix the communication again.
+		If you don't want to use RX timeout set it to -1.
+
+endif #LPWAN_SX127X_RXSUPPORT
+
+config LPWAN_SX127X_TXSUPPORT
+	bool "SX127X TX support"
+	default n
+
+config LPWAN_SX127X_LORA
+	bool "SX127X LORA support"
+	default y
+
+if LPWAN_SX127X_LORA
+
+config LPWAN_SX127X_LORA_IMPHEADER
+	int "SX127X LORA implicit header ON"
+	range 0 1
+	default 0
+
+endif # LPWAN_SX127X_LORA
+
+config LPWAN_SX127X_FSKOOK
+	bool "SX127X FSK/OOK support"
+	default n
+
+if LPWAN_SX127X_FSKOOK
+
+choice
+	prompt "SX127X Bitrate"
+	default LPWAN_SX127X_FSKOOK_4800
+
+config LPWAN_SX127X_FSKOOK_4800
+	bool "4800 BPS"
+
+config LPWAN_SX127X_FSKOOK_38400
+	bool "38400 BPS"
+
+config LPWAN_SX127X_FSKOOK_76800
+	bool "76800 BPS"
+
+endchoice
+
+endif # LPWAN_SX127X_FSKOOK
+
+endif # WL_SX127X

drivers/wireless/lpwan/sx127x/sx127x.c

@@ -77,6 +77,8 @@
 
 #define SX127X_FREQ_CALIBRATION       (CONFIG_LPWAN_SX127X_RFFREQ_DEFAULT)
 
+#ifdef CONFIG_LPWAN_SX127X_FSKOOK_4800
+
 /* FSK default frequency deviation is 5kHz */
 
 #define SX127X_FDEV_DEFAULT           (5000)
@@ -90,6 +92,42 @@
 #define SX127X_FSKOOK_RXBW_DEFAULT    FSKOOK_BANDWIDTH_15P6KHZ
 #define SX127X_FSKOOK_AFCBW_DEFAULT   FSKOOK_BANDWIDTH_20P8KHZ
 
+#endif /* CONFIG_LPWAN_SX127X_FSKOOK_4800 */
+
+#ifdef CONFIG_LPWAN_SX127X_FSKOOK_38400
+
+/* FSK frequency deviation for 38400 is 20kHz */
+
+#define SX127X_FDEV_DEFAULT           (20000)
+
+/* FSK/OOK bitrate default */
+
+#define SX127X_FOM_BITRATE_DEFAULT    (38400)
+
+/* FSK/OOK bandwidth for 38400 */
+
+#define SX127X_FSKOOK_RXBW_DEFAULT    FSKOOK_BANDWIDTH_250KHZ
+#define SX127X_FSKOOK_AFCBW_DEFAULT   FSKOOK_BANDWIDTH_250KHZ
+
+#endif /* CONFIG_LPWAN_SX127X_FSKOOK_38400 */
+
+#ifdef CONFIG_LPWAN_SX127X_FSKOOK_76800
+
+/* FSK frequency deviation for 76800 is 75kHz */
+
+#define SX127X_FDEV_DEFAULT           (75000)
+
+/* FSK/OOK bitrate default */
+
+#define SX127X_FOM_BITRATE_DEFAULT    (76800)
+
+/* FSK/OOK bandwidth for 76800 */
+
+#define SX127X_FSKOOK_RXBW_DEFAULT    FSKOOK_BANDWIDTH_250KHZ
+#define SX127X_FSKOOK_AFCBW_DEFAULT   FSKOOK_BANDWIDTH_250KHZ
+
+#endif /* CONFIG_LPWAN_SX127X_FSKOOK_76800 */
+
 /* Default LORA bandwidth */
 
 #define SX127X_LRM_BW_DEFAULT         LORA_BANDWIDTH_7P8KHZ
@@ -278,10 +316,12 @@ struct sx127x_dev_s
   bool     pa_force;              /* Force PA BOOST pin select */
 #endif
 #ifdef CONFIG_LPWAN_SX127X_RXSUPPORT
-  uint32_t rx_timeout;            /* RX timeout (not supported) */
+  uint32_t rx_timeout;            /* RX timeout in milliseconds */
   uint16_t rx_fifo_len;           /* Number of bytes stored in fifo */
   uint16_t nxt_read;              /* Next read index */
   uint16_t nxt_write;             /* Next write index */
+  clock_t  last_rx_tick;          /* Ticks since last RX event to detect timeout */
+  struct work_s rx_watchdog;      /* Watchdog to detect timeout */
 
   /* Circular RX packet buffer */
 
@@ -1238,6 +1278,50 @@ static int sx127x_poll(FAR struct file *filep, FAR struct pollfd *fds,
 #endif
 }
 
+/****************************************************************************
+ * Name: sx127x_rx_watchdog
+ *
+ * Description:
+ *   Watchdog to detect SX127x RX communication stall
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_LPWAN_SX127X_RXSUPPORT
+static void sx127x_rx_watchdog(FAR void *arg)
+{
+  FAR struct sx127x_dev_s *dev = (FAR struct sx127x_dev_s *)arg;
+  clock_t now = clock_systime_ticks();
+
+  if (dev->opmode == SX127X_OPMODE_RX &&
+      (now - dev->last_rx_tick) > MSEC2TICK(dev->rx_timeout))
+    {
+      wlerr("RX stall detected, restarting RX\n");
+
+      /* Leave RX mode to clear AFC + bit sync */
+
+      sx127x_opmode_set(dev, SX127X_OPMODE_STANDBY);
+
+      /* datasheet-safe delay */
+
+      nxsched_usleep(100);
+
+      /* Re-enter RX */
+
+      sx127x_opmode_set(dev, SX127X_OPMODE_RX);
+
+      /* Avoid using old RX tick, otherwise it always will fail */
+
+      dev->last_rx_tick = now;
+    }
+
+  /* Reschedule watchdog */
+
+  work_queue(LPWORK, &dev->rx_watchdog,
+             sx127x_rx_watchdog, dev,
+             MSEC2TICK(dev->rx_timeout));
+}
+#endif
+
 /****************************************************************************
  * Name: sx127x_lora_isr0_process
  *
@@ -1433,6 +1517,21 @@ static int sx127x_fskook_isr0_process(FAR struct sx127x_dev_s *dev)
               ret = sx127x_fskook_rxhandle(dev);
               if (ret > 0)
                 {
+                  /* Should we take care of RX timeout? */
+
+                  if (dev->rx_timeout > 0)
+                    {
+                      /* Keep a track of last RX time to detect timeout */
+
+                      dev->last_rx_tick = clock_systime_ticks();
+
+                      /* Prepare the work queue to take care of RX timeout */
+
+                      work_queue(LPWORK, &dev->rx_watchdog,
+                                 sx127x_rx_watchdog, dev,
+                                 MSEC2TICK(dev->rx_timeout));
+                    }
+
                   if (dev->pfd)
                     {
                       /* Data available for input */
@@ -4166,6 +4265,12 @@ static int sx127x_deinit(FAR struct sx127x_dev_s *dev)
 {
   wlinfo("Deinit sx127x dev\n");
 
+#ifdef CONFIG_LPWAN_SX127X_RXSUPPORT
+  /* Cancel any running watchdog */
+
+  work_cancel(LPWORK, &dev->rx_watchdog);
+#endif
+
   /* Enter SLEEP mode */
 
   sx127x_opmode_set(dev, SX127X_OPMODE_SLEEP);
@@ -4521,6 +4626,7 @@ static int sx127x_unregister(FAR struct sx127x_dev_s *dev)
   nxsem_destroy(&dev->tx_sem);
 #endif
 #ifdef CONFIG_LPWAN_SX127X_RXSUPPORT
+  work_cancel(LPWORK, &dev->rx_watchdog);
   nxsem_destroy(&dev->rx_sem);
   nxmutex_destroy(&dev->rx_buffer_lock);
 #endif
@@ -4576,6 +4682,9 @@ int sx127x_register(FAR struct spi_dev_s *spi,
   dev->crcon          = CONFIG_LPWAN_SX127X_CRCON;
 #ifdef CONFIG_LPWAN_SX127X_FSKOOK
   dev->fskook.fixlen  = false;
+#  ifdef CONFIG_LPWAN_SX127X_RXSUPPORT
+  dev->rx_timeout     = CONFIG_LPWAN_SX127X_RX_TIMEOUT;
+#  endif
 #endif
 #ifdef CONFIG_LPWAN_SX127X_LORA
   dev->lora.invert_iq = false;