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 <[email protected]> Cc: Benoit Parrot <[email protected]> Cc: Alexandre Courbot <[email protected]> --- 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
