Re: [PATCH] serial/efm32: add new driver

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello,

On Wed, Dec 21, 2011 at 08:28:47PM +0000, Alan Cox wrote:
> On Wed, 21 Dec 2011 16:05:59 +0100
> Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:
> 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > ---
> > Hello,
> > 
> > note that ARCH_EFM32 isn't in mainline yet, so to be actually usable
> > some arch patches are needed.
> 
> Start by running it through the CodingStyle scripts as I see a //
> comment in there 8)
oops

> > +static void efm32_usart_rx_chars(struct efm32_usart_port *efm_port)
> > +{
> > +	struct uart_port *port = &efm_port->port;
> > +	struct tty_struct *tty = port->state->port.tty;
> 
> Needs to be using krefs and checking the tty is not NULL
> (tty_port_tty_get)
ah, I copied from mxs-auart. Will try to find a better example. 
 
> > +static void efm32_usart_set_termios(struct uart_port *port,
> > +		struct ktermios *new, struct ktermios *old)
> > +{
> > +	struct efm32_usart_port *efm_port = to_efm_port(port);
> > +	unsigned long flags;
> > +	unsigned baud;
> > +	u32 clkdiv;
> > +
> > +	/* no modem control lines */
> > +	new->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
> 
> Minor item - HUPCL shouldn't get cleared - its a request for hangup
> behaviour not a port feature.
ah, I copied that from imx (in an if(0) though).
 
> > +	/* currently only some features are implemented */
> > +	new->c_cflag &= ~CSIZE;
> > +	new->c_cflag |= CS8;
> > +	new->c_cflag |= CSTOPB;
> > +	new->c_cflag &= ~PARENB;
> 
> If you can do CS8 without parity you can do CS7 with parity.
I sticked to the things I use and tested. According to the manual the
hardware can do 4 up to 16 data bits with and without parity :-)
 
> > +	new->c_iflag = 0;
> 
> This seems broken. Lots of the iflgs are user requests and stack
> properties not port features. For example you can do xon/xoff as its
> pure software. As far as I can see you should leave c_iflag alone.
ok.

I will send an update and fix the drivers I copied from.

Best regards
Uwe

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