djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

rp2/machine_uart: Fix setting of UART LCR parameters.

Browse Source 
Prior to this change, setting of UART parameters like parity, stop bits or
data bits did not work correctly.  As suggested by @iabdalkader, adding
__DSB() fixes the problem, making sure that changes to the UART LCR_H
register are seen by the peripheral.

Note: the FIFO is already enabled in the call to uart_init(), so the call
to uart_set_fifo_enabled() is not required, but kept for visibility.

Fixes issue #10976.
This commit is contained in:
robert-hh 2023-03-08 20:59:24 +01:00 committed by Damien George
parent b5ceb9d577
commit b7ea90d4cb
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
ports/rp2/machine_uart.c
View File

@ -336,7 +336,9 @@ STATIC void machine_uart_init_helper(machine_uart_obj_t *self, size_t n_args, co
uart_init(self->uart, self->baudrate);
uart_set_format(self->uart, self->bits, self->stop, self->parity);
__DSB(); // make sure UARTLCR_H register is written to
uart_set_fifo_enabled(self->uart, true);
__DSB(); // make sure UARTLCR_H register is written to
gpio_set_function(self->tx, GPIO_FUNC_UART);
gpio_set_function(self->rx, GPIO_FUNC_UART);
if (self->invert & UART_INVERT_RX) {