From 98e18edab34eafb2a2dd4568bb8ffb629a828996 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Thu, 6 Oct 2022 17:48:47 +0200
Subject: [PATCH] drivers/dose: make use of checksum module

---
 drivers/dose/Kconfig      |  1 +
 drivers/dose/Makefile.dep |  1 +
 drivers/dose/dose.c       | 20 +++-----------------
 3 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/drivers/dose/Kconfig b/drivers/dose/Kconfig
index aab666ba92e2..081cbdb2c32c 100644
--- a/drivers/dose/Kconfig
+++ b/drivers/dose/Kconfig
@@ -28,6 +28,7 @@ menuconfig MODULE_DOSE
     depends on HAS_PERIPH_GPIO
     depends on HAS_PERIPH_GPIO_IRQ
     depends on HAS_PERIPH_UART
+    select MODULE_CHECKSUM
     select MODULE_CHUNKED_RINGBUFFER
     select MODULE_EUI_PROVIDER
     select MODULE_IOLIST
diff --git a/drivers/dose/Makefile.dep b/drivers/dose/Makefile.dep
index 9de44766c6b4..3805ddfd3949 100644
--- a/drivers/dose/Makefile.dep
+++ b/drivers/dose/Makefile.dep
@@ -7,6 +7,7 @@ ifneq (,$(filter dose_watchdog,$(USEMODULE)))
   FEATURES_REQUIRED += periph_timer_periodic
 endif
 
+USEMODULE += checksum
 USEMODULE += chunked_ringbuffer
 USEMODULE += eui_provider
 USEMODULE += iolist
diff --git a/drivers/dose/dose.c b/drivers/dose/dose.c
index 2c1e8effef92..c641f0ad5d1d 100644
--- a/drivers/dose/dose.c
+++ b/drivers/dose/dose.c
@@ -27,6 +27,7 @@
 #include "irq.h"
 #include "periph/timer.h"
 
+#include "checksum/crc16_ccitt.h"
 #include "net/eui_provider.h"
 #include "net/netdev/eth.h"
 #include "timex.h"
@@ -38,7 +39,6 @@
 #error "DOSE_TIMER_DEV needs to be set by the board"
 #endif
 
-static uint16_t crc16_update(uint16_t crc, uint8_t octet);
 static dose_signal_t state_transit_blocked(dose_t *ctx, dose_signal_t signal);
 static dose_signal_t state_transit_idle(dose_t *ctx, dose_signal_t signal);
 static dose_signal_t state_transit_recv(dose_t *ctx, dose_signal_t signal);
@@ -59,22 +59,10 @@ static int _init(netdev_t *dev);
 static void _poweron(dose_t *dev);
 static void _poweroff(dose_t *dev, dose_state_t sleep_state);
 
-static uint16_t crc16_update(uint16_t crc, uint8_t octet)
-{
-    crc = (uint8_t)(crc >> 8) | (crc << 8);
-    crc ^= octet;
-    crc ^= (uint8_t)(crc & 0xff) >> 4;
-    crc ^= (crc << 8) << 4;
-    crc ^= ((crc & 0xff) << 4) << 1;
-    return crc;
-}
-
 static void _crc_cb(void *ctx, uint8_t *data, size_t len)
 {
     uint16_t *crc = ctx;
-    for (uint8_t *end = data + len; data != end; ++data) {
-        *crc = crc16_update(*crc, *data);
-    }
+    *crc = crc16_ccitt_false_update(*crc, data, len);
 }
 
 static void _init_standby(dose_t *ctx, const dose_params_t *params)
@@ -571,15 +559,13 @@ static int _send(netdev_t *dev, const iolist_t *iolist)
         size_t n = iol->iol_len;
         pktlen += n;
         uint8_t *ptr = iol->iol_base;
+        crc = crc16_ccitt_false_update(crc, ptr, n);
         while (n--) {
             /* Send data octet */
             if (send_data_octet(ctx, *ptr)) {
                 goto collision;
             }
 
-            /* Update CRC */
-            crc = crc16_update(crc, *ptr);
-
             ptr++;
         }
     }