From 89a5e15bcba87df5120d4656e0ff33d4f7cd6152 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Mon, 17 Dec 2018 22:36:25 +0100 Subject: gpio/mmc/of: Respect polarity in the device tree The device tree bindings for the MMC card detect and write protect lines specify that these should be active low unless "cd-inverted" or "wp-inverted" has been specified. However that is not how the kernel code has worked. It has always respected the flags passed to the phandle in the device tree, but respected the "cd-inverted" and "wp-inverted" flags such that if those are set, the polarity will be the inverse of that specified in the device tree. Switch to behaving like the old code did and fix the regression. Fixes: 81c85ec15a19 ("gpio: OF: Parse MMC-specific CD and WP properties") Cc: Bartosz Golaszewski Cc: Guenter Roeck Reported-by: Guenter Roeck Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 49 ++++++++++++++++------------------------------- 1 file changed, 16 insertions(+), 33 deletions(-) (limited to 'drivers/gpio') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index fa8044228f0e..a6e1891217e2 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -54,6 +54,7 @@ static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, } static void of_gpio_flags_quirks(struct device_node *np, + const char *propname, enum of_gpio_flags *flags, int index) { @@ -61,39 +62,21 @@ static void of_gpio_flags_quirks(struct device_node *np, * Handle MMC "cd-inverted" and "wp-inverted" semantics. */ if (IS_ENABLED(CONFIG_MMC)) { - if (of_property_read_bool(np, "cd-gpios")) { - if (of_property_read_bool(np, "cd-inverted")) { - if (*flags & OF_GPIO_ACTIVE_LOW) { - /* "cd-inverted" takes precedence */ - *flags &= ~OF_GPIO_ACTIVE_LOW; - pr_warn("%s GPIO handle specifies CD active low - ignored\n", - of_node_full_name(np)); - } - } else { - /* - * Active low is the default according to the - * SDHCI specification. If the GPIO handle - * specifies the same thing - good. - */ - *flags |= OF_GPIO_ACTIVE_LOW; - } + /* + * Active low is the default according to the + * SDHCI specification and the device tree + * bindings. However the code in the current + * kernel was written such that the phandle + * flags were always respected, and "cd-inverted" + * would invert the flag from the device phandle. + */ + if (!strcmp(propname, "cd-gpios")) { + if (of_property_read_bool(np, "cd-inverted")) + *flags ^= OF_GPIO_ACTIVE_LOW; } - if (of_property_read_bool(np, "wp-gpios")) { - if (of_property_read_bool(np, "wp-inverted")) { - /* "wp-inverted" takes precedence */ - if (*flags & OF_GPIO_ACTIVE_LOW) { - *flags &= ~OF_GPIO_ACTIVE_LOW; - pr_warn("%s GPIO handle specifies WP active low - ignored\n", - of_node_full_name(np)); - } - } else { - /* - * Active low is the default according to the - * SDHCI specification. If the GPIO handle - * specifies the same thing - good. - */ - *flags |= OF_GPIO_ACTIVE_LOW; - } + if (!strcmp(propname, "wp-gpios")) { + if (of_property_read_bool(np, "wp-inverted")) + *flags ^= OF_GPIO_ACTIVE_LOW; } } /* @@ -213,7 +196,7 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, goto out; if (flags) - of_gpio_flags_quirks(np, flags, index); + of_gpio_flags_quirks(np, propname, flags, index); pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", __func__, propname, np, index, -- cgit v1.2.3-59-g8ed1b