use one mutex per uart

Author: Teufelchen1

drivers/include/slipmux.h

@@ -159,6 +159,13 @@ typedef struct {
      * @brief   Device state (decoder-, powerstate)
      */
     uint8_t state;
+#if IS_USED(MODULE_SLIPMUX_STDIO) || IS_USED(MODULE_SLIPMUX_COAP)
+    /**
+     * @brief   Mutex to synchronize write operations to the UART between stdio,
+     *          coap and net / SLIP sub-modules.
+     */
+    mutex_t mutex;
+#endif
 } slipmux_t;
 
 #ifdef __cplusplus

drivers/slipmux/coap.c

@@ -36,16 +36,16 @@ void slipmux_coap_notify(slipmux_t *dev)
     }
 }
 
-void slipmux_coap_send(uint8_t *buf, size_t len, const slipmux_t *dev)
+void slipmux_coap_send(uint8_t *buf, size_t len, slipmux_t *dev)
 {
     uint16_t fcs_sum = crc16_ccitt_fcs_finish(SPECIAL_INIT_FCS, buf, len);
 
-    slipmux_lock();
+    slipmux_lock(dev);
     slipmux_write_byte(dev->config.uart, SLIPMUX_COAP_START);
     slipmux_write_bytes(dev->config.uart, buf, len);
     slipmux_write_bytes(dev->config.uart, (uint8_t *) &fcs_sum, 2);
     slipmux_write_byte(dev->config.uart, SLIPMUX_END);
-    slipmux_unlock();
+    slipmux_unlock(dev);
 }
 
 int slipmux_coap_recv(uint8_t *buf, size_t buf_size, slipmux_t *dev)

drivers/slipmux/include/slipmux_internal.h

@@ -21,7 +21,6 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "isrpipe.h"
 #include "periph/uart.h"
 #include "mutex.h"
 
@@ -36,22 +35,11 @@ extern "C" {
  */
 #define SLIPMUX_DEV_NUM ARRAY_SIZE(slipmux_params)
 
-/**
- * @brief   ISR pipe to hand read bytes to stdin
- */
-extern isrpipe_t slipmux_stdio_isrpipe;
-
 /**
  * @brief   List of slipmux devices.
  */
 extern slipmux_t slipmux_devs[SLIPMUX_DEV_NUM];
 
-/**
- * @brief   Mutex to synchronize write operations to the UART between stdio,
- *          coap and net / SLIP sub-modules.
- */
-extern mutex_t slipmux_mutex;
-
 /**
  * @name    SLIP marker bytes
  * @see     [RFC 1055](https://tools.ietf.org/html/rfc1055)
@@ -150,28 +138,32 @@ void slipmux_write_bytes(uart_t uart, const uint8_t *data, size_t len);
 
 /**
  * @brief   Acquire exclusive access for writing
+ *          Guarded for _stdio or _coap, the idea being that if only _net is
+ *          used, you are most likely to care about performance.
  */
-static inline void slipmux_lock(void)
+static inline void slipmux_lock(slipmux_t *dev)
 {
-    if (IS_USED(MODULE_SLIPMUX_STDIO) || IS_USED(MODULE_SLIPMUX_COAP)) {
-       mutex_lock(&slipmux_mutex);
-    }
+    (void) dev;
+#if IS_USED(MODULE_SLIPMUX_STDIO) || IS_USED(MODULE_SLIPMUX_COAP)
+    mutex_lock(&dev->mutex);
+#endif
 }
 
 /**
  * @brief   Release the exclusive access
  */
-static inline void slipmux_unlock(void)
+static inline void slipmux_unlock(slipmux_t *dev)
 {
-    if (IS_USED(MODULE_SLIPMUX_STDIO) || IS_USED(MODULE_SLIPMUX_COAP)) {
-       mutex_unlock(&slipmux_mutex);
-    }
+    (void) dev;
+#if IS_USED(MODULE_SLIPMUX_STDIO) || IS_USED(MODULE_SLIPMUX_COAP)
+    mutex_unlock(&dev->mutex);
+#endif
 }
 
 #if IS_USED(MODULE_SLIPMUX_COAP)
 /**
  * @brief   Initialise the CoAP handling
- * 
+ *
  * @param[in] dev  The Slipmux device to initialise.
  * @param[in] index  Device number.
  */
@@ -188,7 +180,7 @@ void slipmux_coap_notify(slipmux_t *dev);
 #if IS_USED(MODULE_SLIPMUX_NET)
 /**
  * @brief   Initialise the network handling
- * 
+ *
  * @param[in] dev  The Slipmux device to initialise.
  * @param[in] index  Device number.
  */

drivers/slipmux/net.c

@@ -90,14 +90,14 @@ static int _send(netdev_t *netdev, const iolist_t *iolist)
         return bytes;
     }
 
-    slipmux_lock();
+    slipmux_lock(dev);
     for (const iolist_t *iol = iolist; iol; iol = iol->iol_next) {
         uint8_t *data = iol->iol_base;
         slipmux_write_bytes(dev->config.uart, data, iol->iol_len);
         bytes += iol->iol_len;
     }
     slipmux_write_byte(dev->config.uart, SLIPMUX_END);
-    slipmux_unlock();
+    slipmux_unlock(dev);
     return bytes;
 }
 

drivers/slipmux/stdio.c

@@ -27,7 +27,7 @@ static void _isrpipe_write(void *arg, uint8_t data)
 
 static void _init(void)
 {
-    /* intentionally overwritten in netdev init so we have stdio before
+    /* intentionally overwritten in slipmux init so we have stdio before
      * the network device is initialized */
     uart_init(slipmux_params[0].uart, slipmux_params[0].baudrate,
               _isrpipe_write, &stdin_isrpipe);
@@ -37,11 +37,11 @@ static void _init(void)
 
 static ssize_t _write(const void *buffer, size_t len)
 {
-    slipmux_lock();
+    slipmux_lock(&slipmux_devs[0]);
     slipmux_write_byte(slipmux_params[0].uart, SLIPMUX_STDIO_START);
     slipmux_write_bytes(slipmux_params[0].uart, buffer, len);
     slipmux_write_byte(slipmux_params[0].uart, SLIPMUX_END);
-    slipmux_unlock();
+    slipmux_unlock(&slipmux_devs[0]);
     return len;
 }