From: Jon Hunter <jonathanh@nvidia.com> To: Laxman Dewangan <ldewangan@nvidia.com>, linus.walleij@linaro.org, swarren@wwwdotorg.org, thierry.reding@gmail.com Cc: linux-gpio@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] gpio: tegra: Implement gpio_get_direction callback Date: Fri, 29 Apr 2016 16:30:41 +0100 [thread overview] Message-ID: <57237E21.4090906@nvidia.com> (raw) In-Reply-To: <1461933078-20366-1-git-send-email-ldewangan@nvidia.com> On 29/04/16 13:31, Laxman Dewangan wrote: > Implement gpio_get_direction() callback for Tegra GPIO. > The direction is only valid if the pin is configured as > GPIO. If pin is not configured in GPIO mode then this > function return error. > > This makes debugfs and initial reading of the state of > the lines more accurate. > > Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> > --- > This patch is based on discussion on series > Re: [PATCH V5 0/4] gpio: tegra: Cleanups and support for debounce > From Linus W: > It would be nice if you also implement .get_direction() which makes > debugfs and initial reading of the state of the lines more accurate. > > drivers/gpio/gpio-tegra.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c > index b3ddd92..6f2292b 100644 > --- a/drivers/gpio/gpio-tegra.c > +++ b/drivers/gpio/gpio-tegra.c > @@ -191,6 +191,24 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset, > return 0; > } > > +static int tegra_gpio_get_direction(struct gpio_chip *chip, unsigned offset) > +{ > + struct tegra_gpio_info *tgi = gpiochip_get_data(chip); > + u32 pin_mask = BIT(GPIO_BIT(offset)); > + u32 cnf, oe; > + > + cnf = tegra_gpio_readl(tgi, GPIO_CNF(tgi, offset)); > + oe = tegra_gpio_readl(tgi, GPIO_OE(tgi, offset)); > + if (cnf & pin_mask) { Nit ... does not look like there is any point in reading GPIO_OE if cnf & pin_mask == 0, so you could move the test before reading GPIO_OE and then ... > + if (oe & pin_mask) > + return GPIOF_DIR_OUT; > + > + return GPIOF_DIR_IN; You could ... return (oe & mask) ? GPIOF_DIR_OUT : GPIOF_DIR_IN; Cheers Jon
WARNING: multiple messages have this Message-ID (diff)
From: Jon Hunter <jonathanh@nvidia.com> To: Laxman Dewangan <ldewangan@nvidia.com>, <linus.walleij@linaro.org>, <swarren@wwwdotorg.org>, <thierry.reding@gmail.com> Cc: <linux-gpio@vger.kernel.org>, <linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] gpio: tegra: Implement gpio_get_direction callback Date: Fri, 29 Apr 2016 16:30:41 +0100 [thread overview] Message-ID: <57237E21.4090906@nvidia.com> (raw) In-Reply-To: <1461933078-20366-1-git-send-email-ldewangan@nvidia.com> On 29/04/16 13:31, Laxman Dewangan wrote: > Implement gpio_get_direction() callback for Tegra GPIO. > The direction is only valid if the pin is configured as > GPIO. If pin is not configured in GPIO mode then this > function return error. > > This makes debugfs and initial reading of the state of > the lines more accurate. > > Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> > --- > This patch is based on discussion on series > Re: [PATCH V5 0/4] gpio: tegra: Cleanups and support for debounce > From Linus W: > It would be nice if you also implement .get_direction() which makes > debugfs and initial reading of the state of the lines more accurate. > > drivers/gpio/gpio-tegra.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c > index b3ddd92..6f2292b 100644 > --- a/drivers/gpio/gpio-tegra.c > +++ b/drivers/gpio/gpio-tegra.c > @@ -191,6 +191,24 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset, > return 0; > } > > +static int tegra_gpio_get_direction(struct gpio_chip *chip, unsigned offset) > +{ > + struct tegra_gpio_info *tgi = gpiochip_get_data(chip); > + u32 pin_mask = BIT(GPIO_BIT(offset)); > + u32 cnf, oe; > + > + cnf = tegra_gpio_readl(tgi, GPIO_CNF(tgi, offset)); > + oe = tegra_gpio_readl(tgi, GPIO_OE(tgi, offset)); > + if (cnf & pin_mask) { Nit ... does not look like there is any point in reading GPIO_OE if cnf & pin_mask == 0, so you could move the test before reading GPIO_OE and then ... > + if (oe & pin_mask) > + return GPIOF_DIR_OUT; > + > + return GPIOF_DIR_IN; You could ... return (oe & mask) ? GPIOF_DIR_OUT : GPIOF_DIR_IN; Cheers Jon
next prev parent reply other threads:[~2016-04-29 15:30 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-04-29 12:31 [PATCH] gpio: tegra: Implement gpio_get_direction callback Laxman Dewangan 2016-04-29 12:31 ` Laxman Dewangan 2016-04-29 12:31 ` Laxman Dewangan 2016-04-29 15:30 ` Jon Hunter [this message] 2016-04-29 15:30 ` Jon Hunter [not found] ` <1461933078-20366-1-git-send-email-ldewangan-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> 2016-04-29 16:17 ` Stephen Warren 2016-04-29 16:17 ` Stephen Warren
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