From e10f72bf4b3e8885c1915a119141481e7fc45ca8 Mon Sep 17 00:00:00 2001 From: Andrew Jeffery Date: Thu, 30 Nov 2017 14:25:24 +1030 Subject: gpio: gpiolib: Generalise state persistence beyond sleep General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery Reviewed-by: Charles Keepax Acked-by: Rob Herring Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index e0d59e61b52f..4a2b8d3397c7 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -153,8 +153,8 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, *flags |= GPIO_OPEN_SOURCE; } - if (of_flags & OF_GPIO_SLEEP_MAY_LOSE_VALUE) - *flags |= GPIO_SLEEP_MAY_LOSE_VALUE; + if (of_flags & OF_GPIO_TRANSITORY) + *flags |= GPIO_TRANSITORY; return desc; } @@ -214,6 +214,8 @@ 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; -- cgit From c85823390215e52d68d3826df92a447ed31e5c80 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 27 Dec 2017 16:37:44 +0100 Subject: gpio: of: Support SPI nonstandard GPIO properties Before it was clearly established that all GPIO properties in the device tree shall be named "foo-gpios" (with the deprecated variant "foo-gpio" for single lines) we unfortunately merged a few bindings which named the lines "gpio-foo" instead. This is most prominent in the GPIO SPI driver in Linux which names the lines "gpio-sck", "gpio-mosi" and "gpio-miso". As we want to switch the GPIO SPI driver to using descriptors, we need devm_gpiod_get() to return something reasonable when looking up these in the device tree. Put in a special #ifdef:ed kludge to do this special lookup only for the SPI case and gets compiled out if we're not enabling SPI. If we have more oddly defined legacy GPIOs like this, they can be handled in a similar manner. Reviewed-by: Rob Herring Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 4a2b8d3397c7..13acd0378884 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -117,6 +117,36 @@ 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; +} + struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) @@ -126,6 +156,7 @@ 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, @@ -140,6 +171,10 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, break; } + /* Special handling for SPI GPIOs if used */ + if (IS_ERR(desc)) + desc = of_find_spi_gpio(dev, con_id, &of_flags); + if (IS_ERR(desc)) return desc; -- cgit From 6a537d48461deacc57c07ed86d9915e5aa4b3539 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 27 Dec 2017 16:37:44 +0100 Subject: gpio: of: Support regulator nonstandard GPIO properties Before it was clearly established that all GPIO properties in the device tree shall be named "foo-gpios" (with the deprecated variant "foo-gpio" for single lines) we unfortunately merged a few bindings for regulators with random phandle names. As we want to switch the GPIO regulator driver to using descriptors, we need devm_gpiod_get() to return something reasonable when looking up these in the device tree. Put in a special #ifdef:ed kludge to do this special lookup only for the regulator case and gets compiled out if we're not enabling regulators. Supply a whitelist with properties we accept. Cc: Rob Herring Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 13acd0378884..d2a6656b82cb 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -147,6 +147,41 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id 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) @@ -175,6 +210,10 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, 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)) + desc = of_find_regulator_gpio(dev, con_id, &of_flags); + if (IS_ERR(desc)) return desc; -- cgit From a603a2b8d86ee93ee2107da8ca75fd854fd4ff32 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Sat, 30 Dec 2017 16:26:36 +0100 Subject: gpio: of: Add special quirk to parse regulator flags While most GPIOs are indicated to be active low or open drain using their twocell flags, we have legacy regulator bindings to take into account. Add a quirk respecting the special boolean active-high and open drain flags when parsing regulator nodes for GPIOs. This makes it possible to get rid of duplicated inversion semantics handling in the regulator core and any regulator drivers parsing and handling this separately. Unfortunately the old regulator inversion semantics are specified such that the presence or absence of "enable-active-high" solely controls the semantics, so we cannot deprecate this in favor of the phandle-provided inversion flag, instead any such phandle inversion flag provided in the second cell of a GPIO handle must be actively ignored, so we print a warning to contain the situation and make things easy for the users. Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index d2a6656b82cb..71ba008b7f46 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 +129,8 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, if (IS_ERR(desc)) goto out; + 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)); -- cgit From 605f2d34ea52a14744fe3c6b43708bce7e2eb690 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 16 Jan 2018 23:44:46 +0100 Subject: gpio: of: Fix NPE from OF flags Some calls to of_get_named_gpio() calls sets the flags argument to NULL because they are not interested in the flags. This caused a null pointer exception since we were unconditionally using these flags. Fix it. Fixes: 6a537d48461d ("gpio: of: Support regulator nonstandard GPIO properties") Cc: Heiner Kallweit Reported-by: Heiner Kallweit Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-of.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/gpio/gpiolib-of.c') diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 71ba008b7f46..27e8a339310c 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -129,7 +129,8 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, if (IS_ERR(desc)) goto out; - of_gpio_flags_quirks(np, flags); + 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, -- cgit