From 9ad3b049ed9f8b97d76b0e5986e7258bb0a0c92e Mon Sep 17 00:00:00 2001 From: Simon Goldschmidt Date: Fri, 2 Nov 2018 21:28:08 +0100 Subject: [PATCH] serial: ns16550: add setconfig support Add possibility to update the serial parity used. Signed-off-by: Simon Goldschmidt Reviewed-by: Simon Glass Reviewed-by: Hannes Schmelzer --- drivers/serial/ns16550.c | 43 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 41 insertions(+), 2 deletions(-) diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index 1e6fc6c668..f21c240e64 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -148,10 +148,13 @@ int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate) 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 @@ void NS16550_init(NS16550_t com_port, int baud_divisor) 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) || \ @@ -348,6 +353,39 @@ static int ns16550_serial_setbrg(struct udevice *dev, int baudrate) 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; +} + int ns16550_serial_probe(struct udevice *dev) { struct NS16550 *const com_port = dev_get_priv(dev); @@ -454,6 +492,7 @@ const struct dm_serial_ops ns16550_serial_ops = { .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) -- 2.25.1