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

[Marcin Nowakowski]

Hi Paul,

On 07.06.2017 22:04, Paul Cercueil wrote:
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 <p...@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