From: Markus Pargmann <mpa@pengutronix.de>
To: Laxman Dewangan <ldewangan@nvidia.com>
Cc: linus.walleij@linaro.org, robh+dt@kernel.org, pawel.moll@arm.com,
mark.rutland@arm.com, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
treding@nvidia.com, swarren@wwwdotorg.org,
Benoit Parrot <bparrot@ti.com>,
Alexandre Courbot <acourbot@nvidia.com>
Subject: Re: [PATCH 4/5] gpio: of: Add support to have multiple gpios in gpio-hog
Date: Wed, 9 Mar 2016 07:28:49 +0100 [thread overview]
Message-ID: <20160309062849.GB10454@pengutronix.de> (raw)
In-Reply-To: <1457438528-29054-5-git-send-email-ldewangan@nvidia.com>
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Hi,
On Tue, Mar 08, 2016 at 05:32:07PM +0530, Laxman Dewangan wrote:
> The child node for gpio hogs under gpio controller's node
> provide the mechanism to automatic GPIO request and
> configuration as part of the gpio-controller's driver
> probe function.
>
> Currently, property "gpio" takes one gpios for such
> configuration. Add support to have multiple GPIOs in
> this property so that multiple GPIOs of gpio-controller
> can be configured by this mechanism with one child node.
So if I read this correctly you want to have multiple GPIOs with the
same line name? Why don't you use multiple child nodes with individual
line names?
Best Regards,
Markus
>
> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
> Cc: Benoit Parrot <bparrot@ti.com>
> Cc: Alexandre Courbot <acourbot@nvidia.com>
> ---
> drivers/gpio/gpiolib-of.c | 64 ++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 49 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index d81dbd8..0e4e8fd 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -118,6 +118,21 @@ int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
> }
> EXPORT_SYMBOL(of_get_named_gpio_flags);
>
> +static int of_gpio_get_gpio_cells_size(struct device_node *chip_np)
> +{
> + u32 ncells;
> + int ret;
> +
> + ret = of_property_read_u32(chip_np, "#gpio-cells", &ncells);
> + if (ret)
> + return ret;
> +
> + if (ncells > MAX_PHANDLE_ARGS)
> + return -EINVAL;
> +
> + return ncells;
> +}
> +
> /**
> * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
> * @np: device node to get GPIO from
> @@ -131,6 +146,7 @@ EXPORT_SYMBOL(of_get_named_gpio_flags);
> */
> static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
> const char **name,
> + int gpio_index,
> enum gpio_lookup_flags *lflags,
> enum gpiod_flags *dflags)
> {
> @@ -139,8 +155,8 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
> struct gg_data gg_data = {
> .flags = &xlate_flags,
> };
> - u32 tmp;
> - int i, ret;
> + int ncells;
> + int i, start_index, ret;
>
> chip_np = np->parent;
> if (!chip_np)
> @@ -150,17 +166,16 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
> *lflags = 0;
> *dflags = 0;
>
> - ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
> - if (ret)
> - return ERR_PTR(ret);
> + ncells = of_gpio_get_gpio_cells_size(chip_np);
> + if (ncells < 0)
> + return ERR_PTR(ncells);
>
> - if (tmp > MAX_PHANDLE_ARGS)
> - return ERR_PTR(-EINVAL);
> + start_index = ncells * gpio_index;
>
> - gg_data.gpiospec.args_count = tmp;
> + gg_data.gpiospec.args_count = ncells;
> gg_data.gpiospec.np = chip_np;
> - for (i = 0; i < tmp; i++) {
> - ret = of_property_read_u32_index(np, "gpios", i,
> + for (i = 0; i < ncells; i++) {
> + ret = of_property_read_u32_index(np, "gpios", start_index + i,
> &gg_data.gpiospec.args[i]);
> if (ret)
> return ERR_PTR(ret);
> @@ -211,18 +226,37 @@ static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
> enum gpio_lookup_flags lflags;
> enum gpiod_flags dflags;
> int ret;
> + int i, ncells, ngpios;
> +
> + ncells = of_gpio_get_gpio_cells_size(chip->of_node);
> + if (ncells < 0)
> + return 0;
>
> for_each_available_child_of_node(chip->of_node, np) {
> if (!of_property_read_bool(np, "gpio-hog"))
> continue;
>
> - desc = of_parse_own_gpio(np, &name, &lflags, &dflags);
> - if (IS_ERR(desc))
> + ngpios = of_property_count_u32_elems(np, "gpios");
> + if (ngpios < 0)
> + continue;
> +
> + if (ngpios % ncells) {
> + dev_warn(chip->parent,
> + "GPIOs entries are not proper in gpios\n");
> continue;
> + }
> +
> + ngpios /= ncells;
> + for (i = 0; i < ngpios; i++) {
> + desc = of_parse_own_gpio(np, &name, i,
> + &lflags, &dflags);
> + if (IS_ERR(desc))
> + continue;
>
> - ret = gpiod_hog(desc, name, lflags, dflags);
> - if (ret < 0)
> - return ret;
> + ret = gpiod_hog(desc, name, lflags, dflags);
> + if (ret < 0)
> + return ret;
> + }
> }
>
> return 0;
> --
> 2.1.4
>
> --
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next prev parent reply other threads:[~2016-03-09 6:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-08 12:02 [PATCH 0/5] gpio: of: Add error handling and support for multiple gpio in gpio-hog Laxman Dewangan
2016-03-08 12:02 ` [PATCH 1/5] gpio: of: Scan available child node for gpio-hog Laxman Dewangan
2016-03-08 14:18 ` Thierry Reding
2016-03-08 12:02 ` [PATCH 2/5] gpio: gpiolib: Print error number if gpio hog failed Laxman Dewangan
2016-03-08 12:27 ` Vladimir Zapolskiy
2016-03-08 14:22 ` Thierry Reding
2016-03-08 15:32 ` Laxman Dewangan
2016-03-09 17:07 ` Stephen Warren
2016-03-10 6:58 ` Laxman Dewangan
2016-03-08 12:02 ` [PATCH 3/5] gpio: of: Return error if gpio hog configuration failed Laxman Dewangan
2016-03-08 14:23 ` Thierry Reding
2016-03-09 17:11 ` Stephen Warren
2016-03-10 7:02 ` Laxman Dewangan
2016-03-08 12:02 ` [PATCH 4/5] gpio: of: Add support to have multiple gpios in gpio-hog Laxman Dewangan
2016-03-09 6:28 ` Markus Pargmann [this message]
2016-03-09 13:20 ` Laxman Dewangan
2016-03-09 17:17 ` Stephen Warren
2016-03-10 7:07 ` Laxman Dewangan
2016-03-10 11:16 ` Markus Pargmann
2016-03-10 11:53 ` Laxman Dewangan
2016-03-17 15:46 ` Rob Herring
2016-03-17 17:44 ` Laxman Dewangan
2016-03-08 12:02 ` [PATCH 5/5] gpio: DT: Rephrase property "gpios" of hog node to support multiple gpios Laxman Dewangan
2016-03-09 17:18 ` Stephen Warren
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