diff options
Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
| -rw-r--r-- | drivers/gpio/gpiolib-of.c | 135 |
1 files changed, 132 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index bfcd20699ec8..84e5a9df2344 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -56,6 +56,42 @@ static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, return gpiochip_get_desc(chip, ret); } +static void of_gpio_flags_quirks(struct device_node *np, + enum of_gpio_flags *flags) +{ + /* + * Some GPIO fixed regulator quirks. + * Note that active low is the default. + */ + if (IS_ENABLED(CONFIG_REGULATOR) && + (of_device_is_compatible(np, "reg-fixed-voltage") || + of_device_is_compatible(np, "regulator-gpio"))) { + /* + * The regulator GPIO handles are specified such that the + * presence or absence of "enable-active-high" solely controls + * the polarity of the GPIO line. Any phandle flags must + * be actively ignored. + */ + if (*flags & OF_GPIO_ACTIVE_LOW) { + pr_warn("%s GPIO handle specifies active low - ignored\n", + of_node_full_name(np)); + *flags &= ~OF_GPIO_ACTIVE_LOW; + } + if (!of_property_read_bool(np, "enable-active-high")) + *flags |= OF_GPIO_ACTIVE_LOW; + } + /* + * Legacy open drain handling for fixed voltage regulators. + */ + if (IS_ENABLED(CONFIG_REGULATOR) && + of_device_is_compatible(np, "reg-fixed-voltage") && + of_property_read_bool(np, "gpio-open-drain")) { + *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN); + pr_info("%s uses legacy open drain flag - update the DTS if you can\n", + of_node_full_name(np)); + } +} + /** * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API * @np: device node to get GPIO from @@ -93,6 +129,9 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, if (IS_ERR(desc)) goto out; + if (flags) + of_gpio_flags_quirks(np, flags); + pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", __func__, propname, np, index, PTR_ERR_OR_ZERO(desc)); @@ -117,6 +156,71 @@ int of_get_named_gpio_flags(struct device_node *np, const char *list_name, } EXPORT_SYMBOL(of_get_named_gpio_flags); +/* + * The SPI GPIO bindings happened before we managed to establish that GPIO + * properties should be named "foo-gpios" so we have this special kludge for + * them. + */ +static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id, + enum of_gpio_flags *of_flags) +{ + char prop_name[32]; /* 32 is max size of property name */ + struct device_node *np = dev->of_node; + struct gpio_desc *desc; + + /* + * Hopefully the compiler stubs the rest of the function if this + * is false. + */ + if (!IS_ENABLED(CONFIG_SPI_MASTER)) + return ERR_PTR(-ENOENT); + + /* Allow this specifically for "spi-gpio" devices */ + if (!of_device_is_compatible(np, "spi-gpio") || !con_id) + return ERR_PTR(-ENOENT); + + /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */ + snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id); + + desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags); + return desc; +} + +/* + * Some regulator bindings happened before we managed to establish that GPIO + * properties should be named "foo-gpios" so we have this special kludge for + * them. + */ +static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id, + enum of_gpio_flags *of_flags) +{ + /* These are the connection IDs we accept as legacy GPIO phandles */ + const char *whitelist[] = { + "wlf,ldoena", /* Arizona */ + "wlf,ldo1ena", /* WM8994 */ + "wlf,ldo2ena", /* WM8994 */ + }; + struct device_node *np = dev->of_node; + struct gpio_desc *desc; + int i; + + if (!IS_ENABLED(CONFIG_REGULATOR)) + return ERR_PTR(-ENOENT); + + if (!con_id) + return ERR_PTR(-ENOENT); + + for (i = 0; i < ARRAY_SIZE(whitelist); i++) + if (!strcmp(con_id, whitelist[i])) + break; + + if (i == ARRAY_SIZE(whitelist)) + return ERR_PTR(-ENOENT); + + desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags); + return desc; +} + struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) @@ -126,6 +230,7 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, struct gpio_desc *desc; unsigned int i; + /* Try GPIO property "foo-gpios" and "foo-gpio" */ for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { if (con_id) snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, @@ -136,10 +241,31 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, &of_flags); + /* + * -EPROBE_DEFER in our case means that we found a + * valid GPIO property, but no controller has been + * registered so far. + * + * This means we don't need to look any further for + * alternate name conventions, and we should really + * preserve the return code for our user to be able to + * retry probing later. + */ + if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER) + return desc; + if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT)) break; } + /* Special handling for SPI GPIOs if used */ + if (IS_ERR(desc)) + desc = of_find_spi_gpio(dev, con_id, &of_flags); + + /* Special handling for regulator GPIOs if used */ + if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER) + desc = of_find_regulator_gpio(dev, con_id, &of_flags); + if (IS_ERR(desc)) return desc; @@ -153,8 +279,8 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, *flags |= GPIO_OPEN_SOURCE; } - if (of_flags & OF_GPIO_SLEEP_MAY_LOOSE_VALUE) - *flags |= GPIO_SLEEP_MAY_LOOSE_VALUE; + if (of_flags & OF_GPIO_TRANSITORY) + *flags |= GPIO_TRANSITORY; return desc; } @@ -214,6 +340,8 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np, if (xlate_flags & OF_GPIO_ACTIVE_LOW) *lflags |= GPIO_ACTIVE_LOW; + if (xlate_flags & OF_GPIO_TRANSITORY) + *lflags |= GPIO_TRANSITORY; if (of_property_read_bool(np, "input")) *dflags |= GPIOD_IN; @@ -493,7 +621,8 @@ int of_gpiochip_add(struct gpio_chip *chip) /* If the chip defines names itself, these take precedence */ if (!chip->names) - devprop_gpiochip_set_names(chip); + devprop_gpiochip_set_names(chip, + of_fwnode_handle(chip->of_node)); of_node_get(chip->of_node); |