driver: add rs485 half duplex interface support to uart driver (fix indentation after...

An existing UART driver does not support RS485 half duplex mode.
This task adds this functionality to ESP_IDF UART driver.
driver/uart.c/h: updated to add support of RS485 half duplex mode
examples/peripherals/uart_echo_rs485/main/rs485_example.c: added test example
components/driver/test/test_uart.c: added test of RS485 half duplex mode
docs/en/api-reference/peripherals/uart.rst: updated documentation
test_uart.c: suppress GCC warnings about discarded const qualifiers
uart.rst: remove sphinx warning - "Duplicate explicit target name"
simple change in uart.h file
update (test_uart.c) after rebase from master
update uart.rst, uart.c, rs485_example.c
Update example description in file Readme.md
update uart.c/h, uart.rst, test_uart.c according to review results
update uart.h (uart_set_rx_timeout() description
test_uart.c remove ignore tag
uart.c/h: fix param errors
test_uart.c: Remove GCC warning supress
uart.rst: fix the notes
rs485_example.c: fix output

The tests are completed using RS485 adapters hardware connected to two ESP32 WROVER KITs.

TW#13812
Closes https://github.com/espressif/esp-idf/pull/667
Closes https://github.com/espressif/esp-idf/pull/1006

diff --git a/components/driver/include/driver/uart.h b/components/driver/include/driver/uart.h
index a756377a76f4eb3ba4d9c60b3663c9fdf45da90d..ed85e18a11b03579458e66ef02d0102ff13fe6b9 100644 (file)
--- a/components/driver/include/driver/uart.h
+++ b/components/driver/include/driver/uart.h
@@ -594,7 +594,7 @@ int uart_write_bytes(uart_port_t uart_num, const char* src, size_t size);
 /**
  * @brief Send data to the UART port from a given buffer and length,
  *
-* If the UART driver's parameter 'tx_buffer_size' is set to zero:
+ * If the UART driver's parameter 'tx_buffer_size' is set to zero:
  * This function will not return until all the data and the break signal have been sent out.
  * After all data is sent out, send a break signal.
  *