[PATCH 08/12] serial: mxs-auart: convert to clk_prepare/clk_unprepare

[Russell King - ARM Linux]

On Tue, Dec 20, 2011 at 03:07:50PM +0100, Uwe Kleine-König wrote:
> Hello,
> 
> On Tue, Dec 20, 2011 at 02:49:13PM +0100, Marek Vasut wrote:
> > > The patch converts mxs-auart driver to clk_prepare/clk_unprepare by
> > > using helper functions clk_prepare_enable/clk_disable_unprepare.
> > > 
> > > Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> > > Cc: Sascha Hauer <s.hauer at pengutronix.de>
> > > Cc: Alan Cox <alan at linux.intel.com>
> > > ---
> > >  drivers/tty/serial/mxs-auart.c |    8 ++++----
> > >  1 files changed, 4 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/drivers/tty/serial/mxs-auart.c
> > > b/drivers/tty/serial/mxs-auart.c index 7e02c9c..c33500a 100644
> > > --- a/drivers/tty/serial/mxs-auart.c
> > > +++ b/drivers/tty/serial/mxs-auart.c
> > > @@ -424,7 +424,7 @@ static int mxs_auart_startup(struct uart_port *u)
> > >  {
> > >  	struct mxs_auart_port *s = to_auart_port(u);
> > > 
> > > -	clk_enable(s->clk);
> > > +	clk_prepare_enable(s->clk);
> > > 
> > >  	writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
> > > 
> > > @@ -453,7 +453,7 @@ static void mxs_auart_shutdown(struct uart_port *u)
> > >  	writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
> > >  			u->membase + AUART_INTR_CLR);
> > > 
> > > -	clk_disable(s->clk);
> > > +	clk_disable_unprepare(s->clk);
> > >  }
> > > 
> > >  static unsigned int mxs_auart_tx_empty(struct uart_port *u)
> > > @@ -634,7 +634,7 @@ auart_console_setup(struct console *co, char *options)
> > >  	if (!s)
> > >  		return -ENODEV;
> > > 
> > > -	clk_enable(s->clk);
> > > +	clk_prepare_enable(s->clk);
> > > 
> > >  	if (options)
> > >  		uart_parse_options(options, &baud, &parity, &bits, &flow);
> > > @@ -643,7 +643,7 @@ auart_console_setup(struct console *co, char *options)
> > > 
> > >  	ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
> > > 
> > > -	clk_disable(s->clk);
> > > +	clk_disable_unprepare(s->clk);
> > > 
> > >  	return ret;
> > >  }
> > 
> > DTTO here, are you sure all of them are not called from atomic ctx?
> the startup callback is called with irqs off.

It shouldn't be, as it has to do things like request_irq() which can
sleep.  The documentation in Documentation/serial/driver is now out
of date, and can't be relied upon.