Thread (92 messages) 92 messages, 7 authors, 2017-12-29

Re: [PATCH 06/15] serial: 8250_ingenic: Parse earlycon options

From: Marcin Nowakowski <hidden>
Date: 2017-06-08 07:31:18
Also in: linux-clk, linux-mips, lkml

Hi Paul,

On 07.06.2017 22:04, Paul Cercueil wrote:
quoted hunk ↗ jump to hunk
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@crapouillou.net>
---
  drivers/tty/serial/8250/8250_ingenic.c | 14 ++++++++++++--
  1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index b31b2ca552d1..59f3e632df49 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -99,14 +99,24 @@ 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) {
+		char options[256];
+		unsigned int parity, bits, flow; /* unused for now */
+
+		strlcpy(options, opt, sizeof(options));
Rather than adding this extra local copy maybe you could instead:

-void uart_parse_options(char *options, int *baud, int *parity, int *bits,
+void uart_parse_options(const char *options, int *baud, int *parity, 
int *bits,

I cannot see any reason why uart_parse_options shouldn't take 'const 
char *options' as an argument.
+		uart_parse_options(options, &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);

Marcin
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help