From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Date: Mon, 17 Jun 2013 10:58:57 +0000 Subject: Re: [PATCH] gpio-rcar: Use OUTDT when reading GPIOs configured as output Message-Id: <1599004.HmR35SYjby@avalon> List-Id: References: <20130616234152.23721.85467.sendpatchset@w520> In-Reply-To: <20130616234152.23721.85467.sendpatchset@w520> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org Hi Magnus, On Monday 17 June 2013 08:41:52 Magnus Damm wrote: > From: Magnus Damm > > Testing on r8a7790 shows that INDT does not indicate the correct > pin state when reading a GPIO configured as output, so update > the gpio_rcar_get() function to handle this case. Have you checked whether this is true on the other SoCs as well ? Reading back the output register instead of the input register will not allow detection of conflicts. If the hardware can't provide that, fine, but otherwise it would be a nice feature to keep (although it might not get used in practice). > Signed-off-by: Magnus Damm Acked-by: Laurent Pinchart > --- > > drivers/gpio/gpio-rcar.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > --- 0001/drivers/gpio/gpio-rcar.c > +++ work/drivers/gpio/gpio-rcar.c 2013-06-12 09:23:53.000000000 +0900 > @@ -230,7 +230,14 @@ static int gpio_rcar_direction_input(str > > static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset) > { > - return (int)(gpio_rcar_read(gpio_to_priv(chip), INDT) & BIT(offset)); > + u32 bit = BIT(offset); > + > + /* testing on r8a7790 shows that INDT does not show correct pin state > + * when configured as output, so use OUTDT in case of output pins */ > + if (gpio_rcar_read(gpio_to_priv(chip), INOUTSEL) & bit) > + return (int)(gpio_rcar_read(gpio_to_priv(chip), OUTDT) & bit); > + else > + return (int)(gpio_rcar_read(gpio_to_priv(chip), INDT) & bit); > } > > static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int > value) -- Regards, Laurent Pinchart