From 90a6d90df84a98da0367bb5620ec4952d1385797 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sat, 13 Nov 2021 13:32:11 +0100
Subject: [PATCH 1/7] cpu/gd32v: uart: fix function parameter

---
 cpu/gd32v/periph/uart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpu/gd32v/periph/uart.c b/cpu/gd32v/periph/uart.c
index b5277ce208..b54880db29 100644
--- a/cpu/gd32v/periph/uart.c
+++ b/cpu/gd32v/periph/uart.c
@@ -37,7 +37,7 @@ static struct {
     uint8_t data_mask;      /**< mask applied to the data register */
 } isr_ctx[UART_NUMOF];
 
-static inline void _uart_isr(uart_t uart);
+static inline void _uart_isr(unsigned uart);
 
 static inline USART_Type *dev(uart_t uart)
 {

From eabc9a804235f013865a281a78eab3ed2c5de431 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Fri, 12 Nov 2021 20:44:32 +0100
Subject: [PATCH 2/7] cpu/nrf5x_common: fix cast to periph type

---
 cpu/nrf5x_common/periph/i2c_nrf52_nrf9160.c | 4 ++--
 cpu/nrf5x_common/periph/spi_nrf52_nrf9160.c | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/cpu/nrf5x_common/periph/i2c_nrf52_nrf9160.c b/cpu/nrf5x_common/periph/i2c_nrf52_nrf9160.c
index 9b77127d03..516acedcfc 100644
--- a/cpu/nrf5x_common/periph/i2c_nrf52_nrf9160.c
+++ b/cpu/nrf5x_common/periph/i2c_nrf52_nrf9160.c
@@ -125,7 +125,7 @@ void i2c_init(i2c_t dev)
     /* configure dev clock speed */
     bus(dev)->FREQUENCY = i2c_config[dev].speed;
 
-    spi_twi_irq_register_i2c(bus(dev), i2c_isr_handler, (void *)dev);
+    spi_twi_irq_register_i2c(bus(dev), i2c_isr_handler, (void *)(uintptr_t)dev);
 
     /* We expect that the device was being acquired before
      * the i2c_init_master() function is called, so it should be enabled when
@@ -297,7 +297,7 @@ int i2c_write_bytes(i2c_t dev, uint16_t addr, const void *data, size_t len,
 
 void i2c_isr_handler(void *arg)
 {
-    i2c_t dev = (i2c_t)arg;
+    i2c_t dev = (i2c_t)(uintptr_t)arg;
 
     /* Mask interrupts to ensure that they only trigger once */
     bus(dev)->INTENCLR = TWIM_INTEN_STOPPED_Msk | TWIM_INTEN_ERROR_Msk;
diff --git a/cpu/nrf5x_common/periph/spi_nrf52_nrf9160.c b/cpu/nrf5x_common/periph/spi_nrf52_nrf9160.c
index 97d902b886..7d5e500100 100644
--- a/cpu/nrf5x_common/periph/spi_nrf52_nrf9160.c
+++ b/cpu/nrf5x_common/periph/spi_nrf52_nrf9160.c
@@ -63,7 +63,7 @@ static inline bool _in_ram(const uint8_t *data)
 #ifdef ERRATA_SPI_SINGLE_BYTE_WORKAROUND
 void spi_gpio_handler(void *arg)
 {
-    spi_t bus = (spi_t)arg;
+    spi_t bus = (spi_t)(uintptr_t)arg;
 
     /**
      * Immediately disable the IRQ, we only care about one PPI event per
@@ -85,7 +85,7 @@ static void _setup_workaround_for_ftpan_58(spi_t bus)
 {
 #ifdef ERRATA_SPI_SINGLE_BYTE_WORKAROUND
     gpio_init_int(spi_config[bus].sclk, GPIO_OUT, GPIO_BOTH,
-                  spi_gpio_handler, (void *)bus);
+                  spi_gpio_handler, (void *)(uintptr_t)bus);
     gpio_irq_disable(spi_config[bus].sclk);
     uint8_t channel = gpio_int_get_exti(spi_config[bus].sclk);
     assert(channel != 0xff);
@@ -145,7 +145,7 @@ void spi_init_pins(spi_t bus)
     SPI_MOSISEL = spi_config[bus].mosi;
     SPI_MISOSEL = spi_config[bus].miso;
     _setup_workaround_for_ftpan_58(bus);
-    spi_twi_irq_register_spi(dev(bus), spi_isr_handler, (void *)bus);
+    spi_twi_irq_register_spi(dev(bus), spi_isr_handler, (void *)(uintptr_t)bus);
 }
 
 void spi_acquire(spi_t bus, spi_cs_t cs, spi_mode_t mode, spi_clk_t clk)
@@ -251,7 +251,7 @@ void spi_transfer_bytes(spi_t bus, spi_cs_t cs, bool cont,
 
 void spi_isr_handler(void *arg)
 {
-    spi_t bus = (spi_t)arg;
+    spi_t bus = (spi_t)(uintptr_t)arg;
 
     mutex_unlock(&busy[bus]);
     dev(bus)->EVENTS_END = 0;

From 3d8e0d7f434a0ddde86669752f55cf2902c51946 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sat, 13 Nov 2021 15:08:30 +0100
Subject: [PATCH 3/7] cpu/esp32: fix cast to periph type

---
 cpu/esp32/periph/can.c    | 4 ++--
 cpu/esp32/periph/i2c_hw.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/cpu/esp32/periph/can.c b/cpu/esp32/periph/can.c
index c9285e5390..e1c87d8ca5 100644
--- a/cpu/esp32/periph/can.c
+++ b/cpu/esp32/periph/can.c
@@ -592,7 +592,7 @@ static int _esp_can_config(can_t *dev)
 
     /* route CAN interrupt source to CPU interrupt and enable it */
     intr_matrix_set(PRO_CPU_NUM, ETS_CAN_INTR_SOURCE, CPU_INUM_CAN);
-    xt_set_interrupt_handler(CPU_INUM_CAN, _esp_can_intr_handler, (void*)dev);
+    xt_set_interrupt_handler(CPU_INUM_CAN, _esp_can_intr_handler, (void*)(uintptr_t)dev);
     xt_ints_on(BIT(CPU_INUM_CAN));
 
     /* set bittiming from parameters as given in device data */
@@ -733,7 +733,7 @@ static int _esp_can_set_mode(can_t *dev, canopt_state_t state)
 
 static void IRAM_ATTR _esp_can_intr_handler(void *arg)
 {
-    can_t* dev = (can_t *)arg;
+    can_t* dev = (can_t *)(uintptr_t)arg;
 
     assert(arg);
 
diff --git a/cpu/esp32/periph/i2c_hw.c b/cpu/esp32/periph/i2c_hw.c
index 847afc4d6a..1d8df98c22 100644
--- a/cpu/esp32/periph/i2c_hw.c
+++ b/cpu/esp32/periph/i2c_hw.c
@@ -683,7 +683,7 @@ static const uint32_t transfer_int_mask = I2C_TRANS_COMPLETE_INT_ENA
 
 void _i2c_transfer_timeout (void *arg)
 {
-    i2c_t dev = (i2c_t)arg;
+    i2c_t dev = (i2c_t)(uintptr_t)arg;
 
     /* reset the hardware if it I2C got stuck */
     _i2c_reset_hw(dev);
@@ -718,7 +718,7 @@ static void _i2c_transfer (i2c_t dev)
     /* set a timer for the case the I2C hardware gets stuck */
     xtimer_t i2c_timeout = {};
     i2c_timeout.callback = _i2c_transfer_timeout;
-    i2c_timeout.arg = (void*)dev;
+    i2c_timeout.arg = (void*)(uintptr_t)dev;
     xtimer_set(&i2c_timeout, I2C_TRANSFER_TIMEOUT);
 
     /* start execution of commands in command pipeline registers */

From 4664e63ad4adfae4bce9f7f052474747cd642dbf Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sat, 13 Nov 2021 15:10:22 +0100
Subject: [PATCH 4/7] drivers/soft_uart: fix type usage

---
 drivers/soft_uart/soft_uart.c | 2 +-
 tests/driver_soft_uart/main.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/soft_uart/soft_uart.c b/drivers/soft_uart/soft_uart.c
index 5b9ae4b5ab..99aa8c7e20 100644
--- a/drivers/soft_uart/soft_uart.c
+++ b/drivers/soft_uart/soft_uart.c
@@ -287,7 +287,7 @@ static void soft_uart_write_byte(soft_uart_t uart, uint8_t data)
     mutex_lock(&ctx->sync);
 }
 
-void soft_uart_write(uart_t uart, const uint8_t *data, size_t len)
+void soft_uart_write(soft_uart_t uart, const uint8_t *data, size_t len)
 {
     const soft_uart_conf_t *cfg = &soft_uart_config[uart];
     struct uart_ctx *ctx = &soft_uart_ctx[uart];
diff --git a/tests/driver_soft_uart/main.c b/tests/driver_soft_uart/main.c
index 1104babb8b..d5763a55ad 100644
--- a/tests/driver_soft_uart/main.c
+++ b/tests/driver_soft_uart/main.c
@@ -72,7 +72,7 @@ static int parse_dev(char *arg)
 
 static void rx_cb(void *arg, uint8_t data)
 {
-    uart_t dev = (uart_t)arg;
+    uart_t dev = (soft_uart_t)arg;
 
     ringbuffer_add_one(&(ctx[dev].rx_buf), data);
     if (data == '\n' || ringbuffer_full(&(ctx[dev].rx_buf))) {

From 55f2eda956a86486d5f19089b35b633bc8c7e4db Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sat, 13 Nov 2021 15:16:33 +0100
Subject: [PATCH 5/7] tests/periph_uart: fix periph type cast

---
 tests/periph_uart/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/periph_uart/main.c b/tests/periph_uart/main.c
index 0a58ae7d09..e5475f519d 100644
--- a/tests/periph_uart/main.c
+++ b/tests/periph_uart/main.c
@@ -98,7 +98,7 @@ static void rxs_cb(void *arg)
 
 static void rx_cb(void *arg, uint8_t data)
 {
-    uart_t dev = (uart_t)arg;
+    uart_t dev = (uart_t)(uintptr_t)arg;
 
     ringbuffer_add_one(&ctx[dev].rx_buf, data);
 
@@ -113,7 +113,7 @@ static int _self_test(uart_t dev, unsigned baud)
 {
     const char test_string[] = "Hello UART!";
 
-    if (uart_init(UART_DEV(dev), baud, rx_cb, (void *)dev)) {
+    if (uart_init(UART_DEV(dev), baud, rx_cb, (void *)(uintptr_t)dev)) {
         printf("error configuring %u baud\n", baud);
         return -1;
     }

From 3dac8a549332fee72f664ca586f599066c029377 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Sat, 13 Nov 2021 15:39:57 +0100
Subject: [PATCH 6/7] tests/periph_qdec: fix periph type cast

---
 tests/periph_qdec/main.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tests/periph_qdec/main.c b/tests/periph_qdec/main.c
index e4d7555b74..4b865e8374 100644
--- a/tests/periph_qdec/main.c
+++ b/tests/periph_qdec/main.c
@@ -26,17 +26,17 @@
 #include "periph/qdec.h"
 #include "xtimer.h"
 
-void handler(void *arg)
+static void handler(void *arg)
 {
-    qdec_t qdec = (qdec_t)arg;
+    qdec_t qdec = (qdec_t)(uintptr_t)arg;
     printf("QDEC %u counter overflow : reset counter\n", qdec);
     qdec_read_and_reset(QDEC_DEV(qdec));
 }
 
 int main(void)
 {
-    uint32_t i = 0;
-    int32_t value = 0;
+    unsigned i;
+    int32_t value;
     puts("Welcome into Quadrature Decoder (QDEC) test program.");
     puts("This program will count pulses on all available QDEC channels");
     puts("Written for nucleo-f401re, you have to plug signals A and B as follow :");
@@ -45,7 +45,7 @@ int main(void)
     puts("Quadrature decoding mode is set to X4 : counting on all edges on both signals");
 
     for (i = 0; i < QDEC_NUMOF; i++) {
-        int32_t error = qdec_init(QDEC_DEV(i), QDEC_X4, handler, (void *)i);
+        int32_t error = qdec_init(QDEC_DEV(i), QDEC_X4, handler, (void *)(uintptr_t)i);
         if (error) {
             fprintf(stderr,"Not supported mode !\n");
             return error;

From 1768e937101637625b63fa9a147b3e69a0e75707 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Fri, 12 Nov 2021 16:26:36 +0100
Subject: [PATCH 7/7] drivers/periph: use uint_fast8_t as default type

The default driver type is just an index into a device array defined
by the board.

If a platform wants to encode additional information in the device type,
it can define a custom type.

This means we can just set the default type to whatever fits the target
CPU best.

On ARM this will still be a 32 bit word, but on AVR it will by a 8 bit byte.
---
 drivers/include/periph/adc.h   | 4 ++--
 drivers/include/periph/dac.h   | 4 ++--
 drivers/include/periph/i2c.h   | 4 ++--
 drivers/include/periph/pwm.h   | 4 ++--
 drivers/include/periph/qdec.h  | 4 ++--
 drivers/include/periph/spi.h   | 4 ++--
 drivers/include/periph/timer.h | 4 ++--
 drivers/include/periph/uart.h  | 4 ++--
 8 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/include/periph/adc.h b/drivers/include/periph/adc.h
index 16105c355d..b6eb4de713 100644
--- a/drivers/include/periph/adc.h
+++ b/drivers/include/periph/adc.h
@@ -69,14 +69,14 @@ extern "C" {
  * @brief   Define default ADC type identifier
  */
 #ifndef HAVE_ADC_T
-typedef unsigned int adc_t;
+typedef uint_fast8_t adc_t;
 #endif
 
 /**
  * @brief   Default ADC undefined value
  */
 #ifndef ADC_UNDEF
-#define ADC_UNDEF           (UINT_MAX)
+#define ADC_UNDEF           (UINT_FAST8_MAX)
 #endif
 
 /**
diff --git a/drivers/include/periph/dac.h b/drivers/include/periph/dac.h
index ecd49da240..99a7492a74 100644
--- a/drivers/include/periph/dac.h
+++ b/drivers/include/periph/dac.h
@@ -64,7 +64,7 @@ extern "C" {
  * @brief   Define default DAC type identifier
  */
 #ifndef HAVE_DAC_T
-typedef unsigned int dac_t;
+typedef uint_fast8_t dac_t;
 #endif
 
 /**
@@ -79,7 +79,7 @@ enum {
  * @brief   Default DAC undefined value
  */
 #ifndef DAC_UNDEF
-#define DAC_UNDEF           (UINT_MAX)
+#define DAC_UNDEF           (UINT_FAST8_MAX)
 #endif
 
 /**
diff --git a/drivers/include/periph/i2c.h b/drivers/include/periph/i2c.h
index 5267445cff..73c4be0ae0 100644
--- a/drivers/include/periph/i2c.h
+++ b/drivers/include/periph/i2c.h
@@ -139,7 +139,7 @@ extern "C" {
  * @{
  */
 #ifndef I2C_UNDEF
-#define I2C_UNDEF           (UINT_MAX)
+#define I2C_UNDEF           (UINT_FAST8_MAX)
 #endif
 /** @} */
 
@@ -148,7 +148,7 @@ extern "C" {
  * @{
  */
 #ifndef HAVE_I2C_T
-typedef unsigned int i2c_t;
+typedef uint_fast8_t i2c_t;
 #endif
 /**  @} */
 
diff --git a/drivers/include/periph/pwm.h b/drivers/include/periph/pwm.h
index 8692f6b124..d3cedb2b9f 100644
--- a/drivers/include/periph/pwm.h
+++ b/drivers/include/periph/pwm.h
@@ -82,14 +82,14 @@ extern "C" {
  * @brief  Default PWM undefined value
  */
 #ifndef PWM_UNDEF
-#define PWM_UNDEF           (UINT_MAX)
+#define PWM_UNDEF           (UINT_FAST8_MAX)
 #endif
 
 /**
  * @brief   Default PWM type definition
  */
 #ifndef HAVE_PWM_T
-typedef unsigned int pwm_t;
+typedef uint_fast8_t pwm_t;
 #endif
 
 /**
diff --git a/drivers/include/periph/qdec.h b/drivers/include/periph/qdec.h
index 225e9ec779..defba77811 100644
--- a/drivers/include/periph/qdec.h
+++ b/drivers/include/periph/qdec.h
@@ -98,14 +98,14 @@ extern "C" {
  * @brief  Default QDEC undefined value
  */
 #ifndef QDEC_UNDEF
-#define QDEC_UNDEF           (UINT_MAX)
+#define QDEC_UNDEF           (UINT_FAST8_MAX)
 #endif
 
 /**
  * @brief   Default QDEC type definition
  */
 #ifndef HAVE_QDEC_T
-typedef unsigned int qdec_t;
+typedef uint_fast8_t qdec_t;
 #endif
 
 /**
diff --git a/drivers/include/periph/spi.h b/drivers/include/periph/spi.h
index 37ee32bd7e..a30e96376d 100644
--- a/drivers/include/periph/spi.h
+++ b/drivers/include/periph/spi.h
@@ -91,7 +91,7 @@ extern "C" {
  * @brief   Define global value for undefined SPI device
  */
 #ifndef SPI_UNDEF
-#define SPI_UNDEF       (UINT_MAX)
+#define SPI_UNDEF       (UINT_FAST8_MAX)
 #endif
 
 /**
@@ -116,7 +116,7 @@ extern "C" {
  * @brief   Default type for SPI devices
  */
 #ifndef HAVE_SPI_T
-typedef unsigned int spi_t;
+typedef uint_fast8_t spi_t;
 #endif
 
 /**
diff --git a/drivers/include/periph/timer.h b/drivers/include/periph/timer.h
index dae64bf0f1..c1068deaa7 100644
--- a/drivers/include/periph/timer.h
+++ b/drivers/include/periph/timer.h
@@ -56,7 +56,7 @@ extern "C" {
  * @brief   Default value for timer not defined
  */
 #ifndef TIMER_UNDEF
-#define TIMER_UNDEF         (UINT_MAX)
+#define TIMER_UNDEF         (UINT_FAST8_MAX)
 #endif
 
 /**
@@ -66,7 +66,7 @@ extern "C" {
  * and vendor device header.
  */
 #ifndef HAVE_TIMER_T
-typedef unsigned int tim_t;
+typedef uint_fast8_t tim_t;
 #endif
 
 /**
diff --git a/drivers/include/periph/uart.h b/drivers/include/periph/uart.h
index 26b4142132..d20ba34789 100644
--- a/drivers/include/periph/uart.h
+++ b/drivers/include/periph/uart.h
@@ -74,14 +74,14 @@ extern "C" {
  * @brief   Define default UART type identifier
  */
 #ifndef HAVE_UART_T
-typedef unsigned int uart_t;
+typedef uint_fast8_t uart_t;
 #endif
 
 /**
  * @brief   Default UART undefined value
  */
 #ifndef UART_UNDEF
-#define UART_UNDEF          (UINT_MAX)
+#define UART_UNDEF          (UINT_FAST8_MAX)
 #endif
 
 /**