serial: ns16550: add setconfig support
Add possibility to update the serial parity used.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 1e6fc6c..f21c240 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -148,10 +148,13 @@
static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
{
- serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
+ /* to keep serial format, read lcr before writing BKSE */
+ int lcr_val = serial_in(&com_port->lcr) & ~UART_LCR_BKSE;
+
+ serial_out(UART_LCR_BKSE | lcr_val, &com_port->lcr);
serial_out(baud_divisor & 0xff, &com_port->dll);
serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
- serial_out(UART_LCRVAL, &com_port->lcr);
+ serial_out(lcr_val, &com_port->lcr);
}
void NS16550_init(NS16550_t com_port, int baud_divisor)
@@ -181,6 +184,8 @@
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(ns16550_getfcr(com_port), &com_port->fcr);
+ /* initialize serial config to 8N1 before writing baudrate */
+ serial_out(UART_LCRVAL, &com_port->lcr);
if (baud_divisor != -1)
NS16550_setbrg(com_port, baud_divisor);
#if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_SOC_DA8XX) || \
@@ -345,6 +350,39 @@
NS16550_setbrg(com_port, clock_divisor);
+ return 0;
+}
+
+static int ns16550_serial_setconfig(struct udevice *dev, uint serial_config)
+{
+ struct NS16550 *const com_port = dev_get_priv(dev);
+ int lcr_val = UART_LCR_WLS_8;
+ uint parity = SERIAL_GET_PARITY(serial_config);
+ uint bits = SERIAL_GET_BITS(serial_config);
+ uint stop = SERIAL_GET_STOP(serial_config);
+
+ /*
+ * only parity config is implemented, check if other serial settings
+ * are the default one.
+ */
+ if (bits != SERIAL_8_BITS || stop != SERIAL_ONE_STOP)
+ return -ENOTSUPP; /* not supported in driver*/
+
+ switch (parity) {
+ case SERIAL_PAR_NONE:
+ /* no bits to add */
+ break;
+ case SERIAL_PAR_ODD:
+ lcr_val |= UART_LCR_PEN;
+ break;
+ case SERIAL_PAR_EVEN:
+ lcr_val |= UART_LCR_PEN | UART_LCR_EPS;
+ break;
+ default:
+ return -ENOTSUPP; /* not supported in driver*/
+ }
+
+ serial_out(lcr_val, &com_port->lcr);
return 0;
}
@@ -454,6 +492,7 @@
.pending = ns16550_serial_pending,
.getc = ns16550_serial_getc,
.setbrg = ns16550_serial_setbrg,
+ .setconfig = ns16550_serial_setconfig
};
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)