Fix of #11354: Function '_write_r' of ESP32's newlibc does not write the output of function 'write(STDIO_FILENO, ...)' to the UART interface. To fix this problem, module 'newlib_syscalls_default' is now used by default. Function '_write_r' of module 'newlib_syscalls_default' uses 'stdio_write' which in turn uses 'uart_write' if module 'stdio_uart' is used which is now the default case for ESP32.
Moving atmega_stdio_init() to cpu_init() just before periph_init() guarantees
that stdio is available to allow DEBUG() in periph_init(). This also helps to
unify the boot up process of ATmega boards and de-duplicates the stdio init from
board_init().
This commit cleans up magic number and defines bitfields.
Adds error codes for ADDR/DATA NACK and ARBLOSS
Adds error handling, it corrects when an error occurs
Protects from flags that could lockup the bus
For this purpose, adapted AVR libc functions are used. When used, malloc and free functions require 304 additional bytes of code compared to the oneway_malloc module.
This driver is compliant with the candev interface. It has been tested
with STM32F0 and STM32F2 and STM32F413 ONLY at this time but should be
compliant with other STM32Fx devices
xSemaphoreTakeRecursive() returned before the fix: pdFALSE(equal to pdFAIL) when the call was successful in obtaining the semaphore
and pdTRUE(equal to pdPASS) when the call did not successfully obtain the semaphore.
According to freertos documentation:
"pdPASS Returned only if the call to xSemaphoreTakeRecursive() was successful in obtaining the semaphore"
"pdFAIL Returned if the call to xSemaphoreTakeRecursive() did not successfully obtain the semaphore."
Fixed it to return the correct value.
xSemaphoreTake() returned before the fix: pdFALSE(equal to pdFAIL) when the call was successful in obtaining the semaphore
and pdTRUE(equal to pdPASS) when the call did not successfully obtain the semaphore.
According to freertos documentation:
"pdPASS Returned only if the call to xSemaphoreTake() was successful in obtaining the semaphore"
"pdFAIL Returned if the call to xSemaphoreTake() did not successfully obtain the semaphore."
Fixed it to return the correct value.
The GPIO for RX has to be initialized as input before the GPIO for TX can be initialized as output. Otherwise it could lead to creash if RX GPIO was used as output before.
Function uart_set_baudrate which is only used internally was made static and renamed to _uart_set_baudrate to indicate that it is an internal function. Furthermore, an additional waiting for flushed TX FIFO added. The reconfiguration is now handled as critical section.
An additional _ for static symbols has been added by mistake and should be removed. This will make future merging with the reimplementation of ESP8266 easier.
