diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-31 12:25:27 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-01-31 12:25:27 -0800 |
commit | 9798f5178f5791f964562eccedcf4dabe02fd825 (patch) | |
tree | d0d76b4202eaa3d3be3aaa05206e57e02e16ac5b /drivers/gpio/gpiolib-of.c | |
parent | 50081e437872e68300750068754f21d0faac5d86 (diff) | |
parent | d58f2bf261fdf3a3fc916c9999a686f959dcf6b6 (diff) | |
download | linux-9798f5178f5791f964562eccedcf4dabe02fd825.tar.bz2 |
Merge tag 'gpio-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"The is the bulk of GPIO changes for the v4.16 kernel cycle. It is
pretty calm this time around I think. I even got time to get to things
like starting to clean up header includes.
Core changes:
- Disallow open drain and open source flags to be set simultaneously.
This doesn't make electrical sense, and would the hardware actually
respond to this setting, the result would be short circuit.
- ACPI GPIO has a new core infrastructure for handling quirks. The
quirks are there to deal with broken ACPI tables centrally instead
of pushing the work to individual drivers. In the world of BIOS
writers, the ACPI tables are perfect. Until they find a mistake in
it. When such a mistake is found, we can patch it with a quirk. It
should never happen, the problem is that it happens. So we
accomodate for it.
- Several documentation updates.
- Revert the patch setting up initial direction state from reading
the device. This was causing bad things for drivers that can't read
status on all its pins. It is only affecting debugfs information
quality.
- Label descriptors with the device name if no explicit label is
passed in.
- Pave the ground for transitioning SPI and regulators to use GPIO
descriptors by implementing some quirks in the device tree GPIO
parsing code.
New drivers:
- New driver for the Access PCIe IDIO 24 family.
Other:
- Major refactorings and improvements to the GPIO mockup driver used
for test and verification.
- Moved the AXP209 driver over to pin control since it gained a pin
control back-end. These patches will appear (with the same hashes)
in the pin control pull request as well.
- Convert the onewire GPIO driver w1-gpio to use descriptors. This is
merged here since the W1 maintainers send very few pull requests
and he ACKed it.
- Start to clean up driver headers using <linux/gpio.h> to just use
<linux/gpio/driver.h> as appropriate"
* tag 'gpio-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (103 commits)
gpio: Timestamp events in hardirq handler
gpio: Fix kernel stack leak to userspace
gpio: Fix a documentation spelling mistake
gpio: Documentation update
gpiolib: remove redundant initialization of pointer desc
gpio: of: Fix NPE from OF flags
gpio: stmpe: Delete an unnecessary variable initialisation in stmpe_gpio_probe()
gpio: stmpe: Move an assignment in stmpe_gpio_probe()
gpio: stmpe: Improve a size determination in stmpe_gpio_probe()
gpio: stmpe: Use seq_putc() in stmpe_dbg_show()
gpio: No NULL owner
gpio: stmpe: i2c transfer are forbiden in atomic context
gpio: davinci: Include proper header
gpio: da905x: Include proper header
gpio: cs5535: Include proper header
gpio: crystalcove: Include proper header
gpio: bt8xx: Include proper header
gpio: bcm-kona: Include proper header
gpio: arizona: Include proper header
gpio: amd8111: Include proper header
...
Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
-rw-r--r-- | drivers/gpio/gpiolib-of.c | 119 |
1 files changed, 117 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 72a0695d2ac3..564bb7a31da4 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, @@ -140,6 +245,14 @@ 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); + + /* 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; @@ -153,8 +266,8 @@ 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 +327,8 @@ 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; |