[PATCH v3 09/18] serial: 8250_ingenic: Parse earlycon options

From: Paul Cercueil
Date: Sun Jul 02 2017 - 12:32:47 EST


In the devicetree, it is possible to specify the baudrate, parity,
bits, flow of the early console, by passing a configuration string like
this:

aliases {
serial0 = &uart0;
};

chosen {
stdout-path = "serial0:57600n8";
};

This, for instance, will configure the early console for a baudrate of
57600 bps, no parity, and 8 bits per baud.

This patches implements parsing of this configuration string in the
8250_ingenic driver, which previously just ignored it.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_ingenic.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

v2: Don't create temp. buffer, now that uart_parse_options takes a const char*
v3: No change

diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index b31b2ca552d1..be4a07a24342 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -99,14 +99,22 @@ static int __init ingenic_early_console_setup(struct earlycon_device *dev,
const char *opt)
{
struct uart_port *port = &dev->port;
- unsigned int baud, divisor;
+ unsigned int divisor;
+ int baud = 115200;

if (!dev->port.membase)
return -ENODEV;

+ if (opt) {
+ unsigned int parity, bits, flow; /* unused for now */
+
+ uart_parse_options(opt, &baud, &parity, &bits, &flow);
+ }
+
ingenic_early_console_setup_clock(dev);

- baud = dev->baud ?: 115200;
+ if (dev->baud)
+ baud = dev->baud;
divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);

early_out(port, UART_IER, 0);
--
2.11.0