From 2d2126e909525cbf5a857198a7dda9a651bdd8d8 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 10:57:44 +0100
Subject: [PATCH 1/8] drivers/uart: use uint8_t for data in cb signature

---
 drivers/include/periph/uart.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/include/periph/uart.h b/drivers/include/periph/uart.h
index bfe12559188f..42fa74e50967 100644
--- a/drivers/include/periph/uart.h
+++ b/drivers/include/periph/uart.h
@@ -98,7 +98,7 @@ typedef unsigned int uart_t;
  * @param[in] arg           context to the callback (optional)
  * @param[in] data          the byte that was received
  */
-typedef void(*uart_rx_cb_t)(void *arg, char data);
+typedef void(*uart_rx_cb_t)(void *arg, uint8_t data);
 
 /**
  * @brief   Interrupt context for a UART device

From 4b67fccf2b28cbd8a4b01b714e9e2166431fa873 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 10:58:14 +0100
Subject: [PATCH 2/8] sys/uart_stdio: adapted to cb type change

---
 sys/include/uart_stdio.h    | 2 +-
 sys/uart_stdio/uart_stdio.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/sys/include/uart_stdio.h b/sys/include/uart_stdio.h
index 6e467261527f..aed349dd923a 100644
--- a/sys/include/uart_stdio.h
+++ b/sys/include/uart_stdio.h
@@ -81,7 +81,7 @@ int uart_stdio_write(const char* buffer, int len);
  * @param[in]   arg     (unused)
  * @param[in]   data    character that has been received
  */
-void uart_stdio_rx_cb(void *arg, char data);
+void uart_stdio_rx_cb(void *arg, uint8_t data);
 
 #ifdef __cplusplus
 }
diff --git a/sys/uart_stdio/uart_stdio.c b/sys/uart_stdio/uart_stdio.c
index 18272ad16d91..14dace5e5c86 100644
--- a/sys/uart_stdio/uart_stdio.c
+++ b/sys/uart_stdio/uart_stdio.c
@@ -52,10 +52,10 @@ static tsrb_t _rx_buf = TSRB_INIT(_rx_buf_mem);
 /**
  * @brief Receive a new character from the UART and put it into the receive buffer
  */
-void uart_stdio_rx_cb(void *arg, char data)
+void uart_stdio_rx_cb(void *arg, uint8_t data)
 {
     (void)arg;
-    tsrb_add_one(&_rx_buf, data);
+    tsrb_add_one(&_rx_buf, (uint8_t)data);
     mutex_unlock(&_rx_mutex);
 }
 

From 18ae50ad4eab711ebd5d0f5ddd251a4fcbe88d4c Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 10:58:29 +0100
Subject: [PATCH 3/8] tests/periph_uart: adapted to cb type
 changtests/periph_uart: adapted to cb type changee

---
 tests/periph_uart/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/periph_uart/main.c b/tests/periph_uart/main.c
index 52fbd19871c7..56b85c99301c 100644
--- a/tests/periph_uart/main.c
+++ b/tests/periph_uart/main.c
@@ -63,7 +63,7 @@ static int parse_dev(char *arg)
     return dev;
 }
 
-static void rx_cb(void *arg, char data)
+static void rx_cb(void *arg, uint8_t data)
 {
     int dev = (int)arg;
 

From b23cde98cf367803ddbb4989e24ed780d05a78f4 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 10:58:54 +0100
Subject: [PATCH 4/8] cpus: adapted UART implementations to cb type change

---
 cpu/ezr32wg/periph/uart.c      | 2 +-
 cpu/lm4f120/periph/uart.c      | 7 ++-----
 cpu/lpc11u34/periph/uart.c     | 2 +-
 cpu/lpc1768/periph/uart.c      | 4 ++--
 cpu/lpc2387/periph/uart.c      | 2 +-
 cpu/msp430fxyz/periph/uart.c   | 2 +-
 cpu/nrf5x_common/periph/uart.c | 2 +-
 cpu/sam3/periph/uart.c         | 2 +-
 cpu/samd21/periph/uart.c       | 2 +-
 cpu/saml21/periph/uart.c       | 2 +-
 cpu/stm32f0/periph/uart.c      | 2 +-
 cpu/stm32f1/periph/uart.c      | 2 +-
 cpu/stm32f3/periph/uart.c      | 2 +-
 cpu/stm32f4/periph/uart.c      | 2 +-
 cpu/stm32l1/periph/uart.c      | 2 +-
 15 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/cpu/ezr32wg/periph/uart.c b/cpu/ezr32wg/periph/uart.c
index ffcb34f65d8e..68ba4a062487 100644
--- a/cpu/ezr32wg/periph/uart.c
+++ b/cpu/ezr32wg/periph/uart.c
@@ -101,7 +101,7 @@ void uart_poweroff(uart_t dev)
 static inline void rx_irq(int dev)
 {
     if (_uart(dev)->IF & USART_IF_RXDATAV) {
-        char data = (char)_uart(dev)->RXDATA;
+        uint8_t data = (uint8_t)_uart(dev)->RXDATA;
         isr_ctx[dev].rx_cb(isr_ctx[dev].arg, data);
     }
     if (sched_context_switch_request) {
diff --git a/cpu/lm4f120/periph/uart.c b/cpu/lm4f120/periph/uart.c
index 93d671247e8a..67c6e4e13e56 100644
--- a/cpu/lm4f120/periph/uart.c
+++ b/cpu/lm4f120/periph/uart.c
@@ -135,11 +135,8 @@ void isr_uart0(void)
     {
         while(ROM_UARTCharsAvail(UART0_BASE))
         {
-            char cChar;
-            long lChar;
-            lChar = ROM_UARTCharGetNonBlocking(UART0_BASE);
-            cChar = (unsigned char)(lChar & 0xFF);
-            config[UART_0].rx_cb(config[UART_0].arg, cChar);
+            long lchar = ROM_UARTCharGetNonBlocking(UART0_BASE);
+            config[UART_0].rx_cb(config[UART_0].arg, (uint8_t)lchar);
         }
     }
     if (sched_context_switch_request) {
diff --git a/cpu/lpc11u34/periph/uart.c b/cpu/lpc11u34/periph/uart.c
index 234f22f64bfa..39ef755e95ec 100644
--- a/cpu/lpc11u34/periph/uart.c
+++ b/cpu/lpc11u34/periph/uart.c
@@ -133,7 +133,7 @@ void uart_poweroff(uart_t uart)
 void UART_0_ISR(void)
 {
     if (UART_0_DEV->LSR & (1 << 0)) {       /* is RDR flag set? */
-        char data = (char)UART_0_DEV->RBR;
+        uint8_t data = (uint8_t)UART_0_DEV->RBR;
         config[UART_0].rx_cb(config[UART_0].arg, data);
     }
     if (sched_context_switch_request) {
diff --git a/cpu/lpc1768/periph/uart.c b/cpu/lpc1768/periph/uart.c
index 37d1a4bebd82..304717792e65 100644
--- a/cpu/lpc1768/periph/uart.c
+++ b/cpu/lpc1768/periph/uart.c
@@ -200,7 +200,7 @@ void uart_poweroff(uart_t uart)
 void UART_0_ISR(void)
 {
     if (UART_0_DEV->LSR & (1 << 0)) {       /* is RDR flag set? */
-        char data = (char)UART_0_DEV->RBR;
+        uint8_t data = (uint8_t)UART_0_DEV->RBR;
         config[UART_0].rx_cb(config[UART_0].arg, data);
     }
     if (sched_context_switch_request) {
@@ -213,7 +213,7 @@ void UART_0_ISR(void)
 void UART_1_ISR(void)
 {
     if (UART_1_DEV->LSR & (1 << 0)) {       /* is RDR flag set? */
-        char data = (char)UART_1_DEV->RBR;
+        uint8_t data = (uint8_t)UART_1_DEV->RBR;
         config[UART_1].rx_cb(config[UART_1].arg, data);
     }
     if (sched_context_switch_request) {
diff --git a/cpu/lpc2387/periph/uart.c b/cpu/lpc2387/periph/uart.c
index dc02f3ae3167..be5926cb3863 100644
--- a/cpu/lpc2387/periph/uart.c
+++ b/cpu/lpc2387/periph/uart.c
@@ -84,7 +84,7 @@ void UART0_IRQHandler(void)
         case UIIR_CTI_INT:              /* Character Timeout Indicator */
         case UIIR_RDA_INT:              /* Receive Data Available */
                 do {
-                    char c = (char)U0RBR;
+                    uint8_t c = (uint8_t)U0RBR;
                     _rx_cb(_cb_arg, c);
                 } while (U0LSR & ULSR_RDR);
             break;
diff --git a/cpu/msp430fxyz/periph/uart.c b/cpu/msp430fxyz/periph/uart.c
index a5475fcdbc29..2010d37a6b15 100644
--- a/cpu/msp430fxyz/periph/uart.c
+++ b/cpu/msp430fxyz/periph/uart.c
@@ -204,7 +204,7 @@ ISR(UART_RX_ISR, isr_uart_0_rx)
     __enter_isr();
 
     uint8_t stat = UART_BASE->ASTAT;
-    char data = (char)UART_BASE->ARXBUF;
+    uint8_t data = (uint8_t)UART_BASE->ARXBUF;
 
     if (stat & (USCI_ASTAT_FE | USCI_ASTAT_OE | USCI_ASTAT_PE | USCI_ASTAT_BRK)) {
         /* some error which we do not handle, just do a pseudo read to reset the
diff --git a/cpu/nrf5x_common/periph/uart.c b/cpu/nrf5x_common/periph/uart.c
index 82f1568c32a2..067c7a6f2767 100644
--- a/cpu/nrf5x_common/periph/uart.c
+++ b/cpu/nrf5x_common/periph/uart.c
@@ -167,7 +167,7 @@ void isr_uart0(void)
 {
     if (NRF_UART0->EVENTS_RXDRDY == 1) {
         NRF_UART0->EVENTS_RXDRDY = 0;
-        char byte = (char)(NRF_UART0->RXD & 0xff);
+        uint8_t byte = (uint8_t)(NRF_UART0->RXD & 0xff);
         uart_config.rx_cb(uart_config.arg, byte);
     }
     if (sched_context_switch_request) {
diff --git a/cpu/sam3/periph/uart.c b/cpu/sam3/periph/uart.c
index 90f72984c7c9..6548071bffa5 100644
--- a/cpu/sam3/periph/uart.c
+++ b/cpu/sam3/periph/uart.c
@@ -99,7 +99,7 @@ static inline void isr_handler(int num)
     Uart *dev = uart_config[num].dev;
 
     if (dev->UART_SR & UART_SR_RXRDY) {
-        ctx[num].rx_cb(ctx[num].arg, (char)dev->UART_RHR);
+        ctx[num].rx_cb(ctx[num].arg, (uint8_t)dev->UART_RHR);
     }
     if (sched_context_switch_request) {
         thread_yield();
diff --git a/cpu/samd21/periph/uart.c b/cpu/samd21/periph/uart.c
index 195beed65935..e2047951d456 100644
--- a/cpu/samd21/periph/uart.c
+++ b/cpu/samd21/periph/uart.c
@@ -135,7 +135,7 @@ static inline void irq_handler(int dev)
 
     if (uart->INTFLAG.reg & SERCOM_USART_INTFLAG_RXC) {
         /* interrupt flag is cleared by reading the data register */
-        uart_ctx[dev].rx_cb(uart_ctx[dev].arg, (char)(uart->DATA.reg));
+        uart_ctx[dev].rx_cb(uart_ctx[dev].arg, (uint8_t)(uart->DATA.reg));
     }
     else if (uart->INTFLAG.reg & SERCOM_USART_INTFLAG_ERROR) {
         /* clear error flag */
diff --git a/cpu/saml21/periph/uart.c b/cpu/saml21/periph/uart.c
index 0e45995595cb..bf0a05e31184 100644
--- a/cpu/saml21/periph/uart.c
+++ b/cpu/saml21/periph/uart.c
@@ -136,7 +136,7 @@ static inline void irq_handler(uint8_t uartnum, SercomUsart *dev)
 {
     if (dev->INTFLAG.bit.RXC) {
         /* cleared by reading DATA regiser */
-        char data = (char)dev->DATA.reg;
+        uint8_t data = (uint8_t)dev->DATA.reg;
         uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
     }
     else if (dev->INTFLAG.bit.ERROR) {
diff --git a/cpu/stm32f0/periph/uart.c b/cpu/stm32f0/periph/uart.c
index 01788d05b76e..64f9aef80c8a 100644
--- a/cpu/stm32f0/periph/uart.c
+++ b/cpu/stm32f0/periph/uart.c
@@ -191,7 +191,7 @@ void uart_poweroff(uart_t uart)
 static inline void irq_handler(uint8_t uartnum, USART_TypeDef *dev)
 {
     if (dev->ISR & USART_ISR_RXNE) {
-        char data = (char)dev->RDR;
+        uint8_t data = (uint8_t)dev->RDR;
         uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
     }
     else if (dev->ISR & USART_ISR_ORE) {
diff --git a/cpu/stm32f1/periph/uart.c b/cpu/stm32f1/periph/uart.c
index c3169aaf76b8..3d18eb4d3b00 100644
--- a/cpu/stm32f1/periph/uart.c
+++ b/cpu/stm32f1/periph/uart.c
@@ -147,7 +147,7 @@ void uart_write(uart_t uart, const uint8_t *data, size_t len)
 static inline void irq_handler(uart_t uartnum, USART_TypeDef *dev)
 {
     if (dev->SR & USART_SR_RXNE) {
-        char data = (char)dev->DR;
+        uint8_t data = (uint8_t)dev->DR;
         config[uartnum].rx_cb(config[uartnum].arg, data);
     }
     else if (dev->SR & USART_SR_ORE) {
diff --git a/cpu/stm32f3/periph/uart.c b/cpu/stm32f3/periph/uart.c
index 9f69fff26cf1..cd1a864d8b47 100644
--- a/cpu/stm32f3/periph/uart.c
+++ b/cpu/stm32f3/periph/uart.c
@@ -187,7 +187,7 @@ void uart_write(uart_t uart, const uint8_t *data, size_t len)
 static inline void irq_handler(uint8_t uartnum, USART_TypeDef *dev)
 {
     if (dev->ISR & USART_ISR_RXNE) {
-        char data = (char)dev->RDR;
+        uint8_t data = (uint8_t)dev->RDR;
         uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
     }
     else if (dev->ISR & USART_ISR_ORE) {
diff --git a/cpu/stm32f4/periph/uart.c b/cpu/stm32f4/periph/uart.c
index d82654224d18..aa0261029f31 100644
--- a/cpu/stm32f4/periph/uart.c
+++ b/cpu/stm32f4/periph/uart.c
@@ -165,7 +165,7 @@ void uart_poweroff(uart_t uart)
 static inline void irq_handler(int uart, USART_TypeDef *dev)
 {
     if (dev->SR & USART_SR_RXNE) {
-        char data = (char)dev->DR;
+        uint8_t data = (uint8_t)dev->DR;
         uart_ctx[uart].rx_cb(uart_ctx[uart].arg, data);
     }
     if (sched_context_switch_request) {
diff --git a/cpu/stm32l1/periph/uart.c b/cpu/stm32l1/periph/uart.c
index be56ca96f5bf..22da881ef7a7 100644
--- a/cpu/stm32l1/periph/uart.c
+++ b/cpu/stm32l1/periph/uart.c
@@ -166,7 +166,7 @@ void uart_write(uart_t uart, const uint8_t *data, size_t len)
 static inline void irq_handler(uint8_t uartnum, USART_TypeDef *dev)
 {
     if (dev->SR & USART_SR_RXNE) {
-        char data = (char)dev->DR;
+        uint8_t data = (uint8_t)dev->DR;
         uart_config[uartnum].rx_cb(uart_config[uartnum].arg, data);
     }
     if (sched_context_switch_request) {

From 368d96ccd1433b3a5ff19fcaaf109a5044354765 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 11:59:08 +0100
Subject: [PATCH 5/8] drivers/xbee: adapted to changed uart cb type

---
 drivers/xbee/xbee.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/xbee/xbee.c b/drivers/xbee/xbee.c
index 69c68dc298e6..ef20a4d87b23 100644
--- a/drivers/xbee/xbee.c
+++ b/drivers/xbee/xbee.c
@@ -136,9 +136,8 @@ static void _api_at_cmd(xbee_t *dev, uint8_t *cmd, uint8_t size, resp_t *resp)
 /*
  * Interrupt callbacks
  */
-static void _rx_cb(void *arg, char _c)
+static void _rx_cb(void *arg, uint8_t c)
 {
-    unsigned char c = _c;
     xbee_t *dev = (xbee_t *)arg;
     msg_t msg;
 
@@ -154,7 +153,7 @@ static void _rx_cb(void *arg, char _c)
             dev->int_state = XBEE_INT_STATE_SIZE2;
             break;
         case XBEE_INT_STATE_SIZE2:
-            dev->int_size += (uint8_t)c;
+            dev->int_size += c;
             dev->int_state = XBEE_INT_STATE_TYPE;
             break;
         case XBEE_INT_STATE_TYPE:
@@ -165,7 +164,7 @@ static void _rx_cb(void *arg, char _c)
                     return;
                 }
                 dev->rx_limit = dev->int_size + 1;
-                dev->rx_buf[dev->rx_count++] = (uint8_t)c;
+                dev->rx_buf[dev->rx_count++] = c;
                 dev->int_state = XBEE_INT_STATE_RX;
             }
             else if (c == API_ID_AT_RESP) {
@@ -177,7 +176,7 @@ static void _rx_cb(void *arg, char _c)
             }
             break;
         case XBEE_INT_STATE_RESP:
-            dev->resp_buf[dev->resp_count++] = (uint8_t)c;
+            dev->resp_buf[dev->resp_count++] = c;
             if (dev->resp_count == dev->resp_limit) {
                 /* here we ignore the checksum to prevent deadlocks */
                 mutex_unlock(&(dev->resp_lock));
@@ -185,7 +184,7 @@ static void _rx_cb(void *arg, char _c)
             }
             break;
         case XBEE_INT_STATE_RX:
-            dev->rx_buf[dev->rx_count++] = (uint8_t)c;
+            dev->rx_buf[dev->rx_count++] = c;
             if (dev->rx_count == dev->rx_limit) {
                 /* packet is complete */
                 msg.type = GNRC_NETDEV_MSG_TYPE_EVENT;

From e855d63d8425c1bb0d7ded75ee5fabd6ce1fb17b Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 11:59:20 +0100
Subject: [PATCH 6/8] net/slip: adapted to uart cb type change

---
 sys/net/gnrc/link_layer/slip/gnrc_slip.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/sys/net/gnrc/link_layer/slip/gnrc_slip.c b/sys/net/gnrc/link_layer/slip/gnrc_slip.c
index ccf55d74f378..9ab655933923 100644
--- a/sys/net/gnrc/link_layer/slip/gnrc_slip.c
+++ b/sys/net/gnrc/link_layer/slip/gnrc_slip.c
@@ -50,9 +50,9 @@
 #define _SLIP_DEV(arg)    ((gnrc_slip_dev_t *)arg)
 
 /* UART callbacks */
-static void _slip_rx_cb(void *arg, char data)
+static void _slip_rx_cb(void *arg, uint8_t data)
 {
-    if (data == _SLIP_END) {
+    if (data == (uint8_t)_SLIP_END) {
         msg_t msg;
 
         msg.type = _SLIP_MSG_TYPE;
@@ -66,14 +66,14 @@ static void _slip_rx_cb(void *arg, char data)
         _SLIP_DEV(arg)->in_esc = 0;
 
         switch (data) {
-            case (_SLIP_END_ESC):
+            case ((uint8_t)_SLIP_END_ESC):
                 if (ringbuffer_add_one(&_SLIP_DEV(arg)->in_buf, _SLIP_END) < 0) {
                     _SLIP_DEV(arg)->in_bytes++;
                 }
 
                 break;
 
-            case (_SLIP_ESC_ESC):
+            case ((uint8_t)_SLIP_ESC_ESC):
                 if (ringbuffer_add_one(&_SLIP_DEV(arg)->in_buf, _SLIP_ESC) < 0) {
                     _SLIP_DEV(arg)->in_bytes++;
                 }
@@ -84,7 +84,7 @@ static void _slip_rx_cb(void *arg, char data)
                 break;
         }
     }
-    else if (data == _SLIP_ESC) {
+    else if (data == (uint8_t)_SLIP_ESC) {
         _SLIP_DEV(arg)->in_esc = 1;
     }
     else {

From 1a8a73af63cd6069c098b83338064602a969b217 Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 14:24:32 +0100
Subject: [PATCH 7/8] drivers/ethos: adapted to changed UART cb type

---
 drivers/ethos/ethos.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ethos/ethos.c b/drivers/ethos/ethos.c
index 7930e7fb210f..41cc0f44b404 100644
--- a/drivers/ethos/ethos.c
+++ b/drivers/ethos/ethos.c
@@ -40,7 +40,7 @@
 #include "debug.h"
 
 static void _get_mac_addr(netdev2_t *dev, uint8_t* buf);
-static void ethos_isr(void *arg, char c);
+static void ethos_isr(void *arg, uint8_t c);
 const static netdev2_driver_t netdev2_driver_ethos;
 
 static const uint8_t _esc_esc[] = {ETHOS_ESC_CHAR, (ETHOS_ESC_CHAR ^ 0x20)};
@@ -126,7 +126,7 @@ static void _end_of_frame(ethos_t *dev)
     _reset_state(dev);
 }
 
-static void ethos_isr(void *arg, char c)
+static void ethos_isr(void *arg, uint8_t c)
 {
     ethos_t *dev = (ethos_t *) arg;
 

From 236bd201ca0a31c8768d0236cc13bddf6cf58e9d Mon Sep 17 00:00:00 2001
From: Hauke Petersen <hauke.petersen@fu-berlin.de>
Date: Tue, 15 Mar 2016 14:24:48 +0100
Subject: [PATCH 8/8] sys/arduino: adapted to changed UART cb type

---
 sys/arduino/serialport.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/arduino/serialport.cpp b/sys/arduino/serialport.cpp
index c9512be5765d..63ac0af9478f 100644
--- a/sys/arduino/serialport.cpp
+++ b/sys/arduino/serialport.cpp
@@ -27,10 +27,10 @@ extern "C" {
 
 #include "serialport.hpp"
 
-void rx_cb(void *arg, char c)
+void rx_cb(void *arg, uint8_t c)
 {
     ringbuffer_t *buf = (ringbuffer_t *)arg;
-    ringbuffer_add_one(buf, c);
+    ringbuffer_add_one(buf, (char)c);
 }
 
 SerialPort::SerialPort(uart_t dev)