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    Subject[PATCH 4/5] gpio: of: Add support to have multiple gpios in gpio-hog
    Date
    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.

    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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