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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-18 12:22:10 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-18 12:22:10 (GMT) |
commit | 510965dd4a0a59504ba38455f77339ea8b4c6a70 (patch) | |
tree | 36492629ac68de94457482562660154f28e9e039 /drivers/gpio/gpiolib-of.c | |
parent | 40d7839879b4584f91522d841afb22ed401cf40f (diff) | |
parent | 03daa6f82f2b634019fe8261698f6af3c133497f (diff) | |
download | linux-510965dd4a0a59504ba38455f77339ea8b4c6a70.tar.xz |
Merge tag 'gpio-v4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.1 development cycle:
- A new GPIO hogging mechanism has been added. This can be used on
boards that want to drive some GPIO line high, low, or set it as
input on boot and then never touch it again. For some embedded
systems this is bliss and simplifies things to a great extent.
- Some API cleanup and closure: gpiod_get_array() and
gpiod_put_array() has been added to get and put GPIOs in bulk as
was possible with the non-descriptor API.
- Encapsulate cross-calls to the pin control subsystem in
<linux/gpio/driver.h>. Now this should be the only header any GPIO
driver needs to include or something is wrong. Cleanups
restricting drivers to this include are welcomed if tested.
- Sort the GPIO Kconfig and split it into submenus, as it was
becoming and unstructured, illogical and unnavigatable mess. I
hope this is easier to follow. Menus that require a certain
subsystem like I2C can now be hidden nicely for example, still
working on others.
- New drivers:
- New driver for the Altera Soft GPIO.
- The F7188x driver now handles the F71869 and F71869A variants.
- The MIPS Loongson driver has been moved to drivers/gpio for
consolidation and cleanup.
- Cleanups:
- The MAX732x is converted to use the GPIOLIB_IRQCHIP
infrastructure.
- The PCF857x is converted to use the GPIOLIB_IRQCHIP
infrastructure.
- Radical cleanup of the OMAP driver.
- Misc:
- Enable the DWAPB GPIO for all architectures. This is a "hard
IP" block from Synopsys which has started to turn up in so
diverse architectures as X86 Quark, ARC and a slew of ARM
systems. So even though it's not an expander, it's generic
enough to be available for all.
- We add a mock GPIO on Crystalcove PMIC after a long discussion
with Daniel Vetter et al, tracing back to the shootout at the
kernel summit where DRM drivers and sub-componentization was
discussed. In this case a mock GPIO is assumed to be the best
compromise gaining some reuse of infrastructure without making
DRM drivers overly complex at the same time. Let's see"
* tag 'gpio-v4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (62 commits)
Revert "gpio: sch: use uapi/linux/pci_ids.h directly"
gpio: dwapb: remove dependencies
gpio: dwapb: enable for ARC
gpio: removing kfree remove functionality
gpio: mvebu: Fix mask/unmask managment per irq chip type
gpio: split GPIO drivers in submenus
gpio: move MFD GPIO drivers under their own comment
gpio: move BCM Kona Kconfig option
gpio: arrange SPI Kconfig symbols alphabetically
gpio: arrange PCI GPIO controllers alphabetically
gpio: arrange I2C Kconfig symbols alphabetically
gpio: arrange Kconfig symbols alphabetically
gpio: ich: Implement get_direction function
gpio: use (!foo) instead of (foo == NULL)
gpio: arizona: drop owner assignment from platform_drivers
gpio: max7300: remove 'ret' variable
gpio: use devm_kzalloc
gpio: sch: use uapi/linux/pci_ids.h directly
gpio: x-gene: fix devm_ioremap_resource() check
gpio: loongson: Add Loongson-3A/3B GPIO driver support
...
Diffstat (limited to 'drivers/gpio/gpiolib-of.c')
-rw-r--r-- | drivers/gpio/gpiolib-of.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index 4650bf8..a6c67c6 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -22,6 +22,7 @@ #include <linux/of_gpio.h> #include <linux/pinctrl/pinctrl.h> #include <linux/slab.h> +#include <linux/gpio/machine.h> #include "gpiolib.h" @@ -118,6 +119,114 @@ int of_get_named_gpio_flags(struct device_node *np, const char *list_name, EXPORT_SYMBOL(of_get_named_gpio_flags); /** + * of_get_gpio_hog() - Get a GPIO hog descriptor, names and flags for GPIO API + * @np: device node to get GPIO from + * @name: GPIO line name + * @lflags: gpio_lookup_flags - returned from of_find_gpio() or + * of_get_gpio_hog() + * @dflags: gpiod_flags - optional GPIO initialization flags + * + * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno + * value on the error condition. + */ +static struct gpio_desc *of_get_gpio_hog(struct device_node *np, + const char **name, + enum gpio_lookup_flags *lflags, + enum gpiod_flags *dflags) +{ + struct device_node *chip_np; + enum of_gpio_flags xlate_flags; + struct gpio_desc *desc; + struct gg_data gg_data = { + .flags = &xlate_flags, + }; + u32 tmp; + int i, ret; + + chip_np = np->parent; + if (!chip_np) + return ERR_PTR(-EINVAL); + + xlate_flags = 0; + *lflags = 0; + *dflags = 0; + + ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); + if (ret) + return ERR_PTR(ret); + + if (tmp > MAX_PHANDLE_ARGS) + return ERR_PTR(-EINVAL); + + gg_data.gpiospec.args_count = tmp; + gg_data.gpiospec.np = chip_np; + for (i = 0; i < tmp; i++) { + ret = of_property_read_u32_index(np, "gpios", i, + &gg_data.gpiospec.args[i]); + if (ret) + return ERR_PTR(ret); + } + + gpiochip_find(&gg_data, of_gpiochip_find_and_xlate); + if (!gg_data.out_gpio) { + if (np->parent == np) + return ERR_PTR(-ENXIO); + else + return ERR_PTR(-EINVAL); + } + + if (xlate_flags & OF_GPIO_ACTIVE_LOW) + *lflags |= GPIO_ACTIVE_LOW; + + if (of_property_read_bool(np, "input")) + *dflags |= GPIOD_IN; + else if (of_property_read_bool(np, "output-low")) + *dflags |= GPIOD_OUT_LOW; + else if (of_property_read_bool(np, "output-high")) + *dflags |= GPIOD_OUT_HIGH; + else { + pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n", + desc_to_gpio(gg_data.out_gpio), np->name); + return ERR_PTR(-EINVAL); + } + + if (name && of_property_read_string(np, "line-name", name)) + *name = np->name; + + desc = gg_data.out_gpio; + + return desc; +} + +/** + * of_gpiochip_scan_hogs - Scan gpio-controller and apply GPIO hog as requested + * @chip: gpio chip to act on + * + * This is only used by of_gpiochip_add to request/set GPIO initial + * configuration. + */ +static void of_gpiochip_scan_hogs(struct gpio_chip *chip) +{ + struct gpio_desc *desc = NULL; + struct device_node *np; + const char *name; + enum gpio_lookup_flags lflags; + enum gpiod_flags dflags; + + for_each_child_of_node(chip->of_node, np) { + if (!of_property_read_bool(np, "gpio-hog")) + continue; + + desc = of_get_gpio_hog(np, &name, &lflags, &dflags); + if (IS_ERR(desc)) + continue; + + if (gpiod_hog(desc, name, lflags, dflags)) + continue; + } +} + +/** * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @gc: pointer to the gpio_chip structure * @np: device node of the GPIO chip @@ -326,6 +435,8 @@ void of_gpiochip_add(struct gpio_chip *chip) of_gpiochip_add_pin_range(chip); of_node_get(chip->of_node); + + of_gpiochip_scan_hogs(chip); } void of_gpiochip_remove(struct gpio_chip *chip) |