[PATCH] ARM: mx28evk: Simplify GPIO requests

[Lothar Waßmann]

Hi,

Shawn Guo writes:
> On Mon, Jan 23, 2012 at 12:41:49PM -0200, Fabio Estevam wrote:
> > Requesting all the GPIOs on a single array (mx28evk_gpios[]) can make the 
> > error handling of gpio_requests much simpler.
> > 
> > Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> 
> Looks good.  A couple trivial comments below though.
> 
> > ---
> > This approach was suggested by Sascha Hauer:
> > http://patchwork.ozlabs.org/patch/124661/
> > 
> >  arch/arm/mach-mxs/mach-mx28evk.c |   72 ++++++++-----------------------------
> >  1 files changed, 16 insertions(+), 56 deletions(-)
> > 
> > diff --git a/arch/arm/mach-mxs/mach-mx28evk.c b/arch/arm/mach-mxs/mach-mx28evk.c
> > index fdb0a56..6260ec3 100644
> > --- a/arch/arm/mach-mxs/mach-mx28evk.c
> > +++ b/arch/arm/mach-mxs/mach-mx28evk.c
> > @@ -223,7 +223,6 @@ static const struct gpio_led_platform_data mx28evk_led_data __initconst = {
> >  /* fec */
> >  static void __init mx28evk_fec_reset(void)
> >  {
> > -	int ret;
> >  	struct clk *clk;
> >  
> >  	/* Enable fec phy clock */
> > @@ -231,32 +230,6 @@ static void __init mx28evk_fec_reset(void)
> >  	if (!IS_ERR(clk))
> >  		clk_prepare_enable(clk);
> >  
> > -	/* Power up fec phy */
> > -	ret = gpio_request(MX28EVK_FEC_PHY_POWER, "fec-phy-power");
> > -	if (ret) {
> > -		pr_err("Failed to request gpio fec-phy-%s: %d\n", "power", ret);
> > -		return;
> > -	}
> > -
> > -	ret = gpio_direction_output(MX28EVK_FEC_PHY_POWER, 0);
> > -	if (ret) {
> > -		pr_err("Failed to drive gpio fec-phy-%s: %d\n", "power", ret);
> > -		return;
> > -	}
> > -
> > -	/* Reset fec phy */
> > -	ret = gpio_request(MX28EVK_FEC_PHY_RESET, "fec-phy-reset");
> > -	if (ret) {
> > -		pr_err("Failed to request gpio fec-phy-%s: %d\n", "reset", ret);
> > -		return;
> > -	}
> > -
> > -	gpio_direction_output(MX28EVK_FEC_PHY_RESET, 0);
> > -	if (ret) {
> > -		pr_err("Failed to drive gpio fec-phy-%s: %d\n", "reset", ret);
> > -		return;
> > -	}
> > -
> >  	mdelay(1);
> 
> This delay is supposed to be in the middle of the two calls here.  As
> we are moving around the first call, can you give it a test to see if
> the mdelay is still mandatory?  I would remove it if it's not necessary.
> 
"Empirical Programming Part One"? The HW will have some timing
requirements that need to be fullfilled. That cannot be done by
'giving it a test' but by reading the appropriate datasheet and
implementing the code accordingly.


Lothar Waßmann
-- 
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