summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-18 08:22:10 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-18 08:22:10 -0400
commit510965dd4a0a59504ba38455f77339ea8b4c6a70 (patch)
tree36492629ac68de94457482562660154f28e9e039 /Documentation
parent40d7839879b4584f91522d841afb22ed401cf40f (diff)
parent03daa6f82f2b634019fe8261698f6af3c133497f (diff)
downloadlinux-510965dd4a0a59504ba38455f77339ea8b4c6a70.tar.bz2
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 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-altera.txt43
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio.txt30
-rw-r--r--Documentation/devicetree/bindings/gpio/mrvl-gpio.txt2
-rw-r--r--Documentation/gpio/consumer.txt65
4 files changed, 135 insertions, 5 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-altera.txt b/Documentation/devicetree/bindings/gpio/gpio-altera.txt
new file mode 100644
index 000000000000..12f50149e1ed
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-altera.txt
@@ -0,0 +1,43 @@
+Altera GPIO controller bindings
+
+Required properties:
+- compatible:
+ - "altr,pio-1.0"
+- reg: Physical base address and length of the controller's registers.
+- #gpio-cells : Should be 2
+ - The first cell is the gpio offset number.
+ - The second cell is reserved and is currently unused.
+- gpio-controller : Marks the device node as a GPIO controller.
+- interrupt-controller: Mark the device node as an interrupt controller
+- #interrupt-cells : Should be 1. The interrupt type is fixed in the hardware.
+ - The first cell is the GPIO offset number within the GPIO controller.
+- interrupts: Specify the interrupt.
+- altr,interrupt-trigger: Specifies the interrupt trigger type the GPIO
+ hardware is synthesized. This field is required if the Altera GPIO controller
+ used has IRQ enabled as the interrupt type is not software controlled,
+ but hardware synthesized. Required if GPIO is used as an interrupt
+ controller. The value is defined in <dt-bindings/interrupt-controller/irq.h>
+ Only the following flags are supported:
+ IRQ_TYPE_EDGE_RISING
+ IRQ_TYPE_EDGE_FALLING
+ IRQ_TYPE_EDGE_BOTH
+ IRQ_TYPE_LEVEL_HIGH
+
+Optional properties:
+- altr,ngpio: Width of the GPIO bank. This defines how many pins the
+ GPIO device has. Ranges between 1-32. Optional and defaults to 32 if not
+ specified.
+
+Example:
+
+gpio_altr: gpio@0xff200000 {
+ compatible = "altr,pio-1.0";
+ reg = <0xff200000 0x10>;
+ interrupts = <0 45 4>;
+ altr,ngpio = <32>;
+ altr,interrupt-trigger = <IRQ_TYPE_EDGE_RISING>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ #interrupt-cells = <1>;
+ interrupt-controller;
+};
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index f7a158d85862..5788d5cf1252 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -116,6 +116,29 @@ Every GPIO controller node must contain both an empty "gpio-controller"
property, and a #gpio-cells integer property, which indicates the number of
cells in a gpio-specifier.
+The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism
+providing automatic GPIO request and configuration as part of the
+gpio-controller's driver probe function.
+
+Each GPIO hog definition is represented as a child node of the GPIO controller.
+Required properties:
+- gpio-hog: A property specifying that this child node represent a GPIO hog.
+- gpios: Store the GPIO information (id, flags, ...). Shall contain the
+ number of cells specified in its parent node (GPIO controller
+ node).
+Only one of the following properties scanned in the order shown below.
+This means that when multiple properties are present they will be searched
+in the order presented below and the first match is taken as the intended
+configuration.
+- input: A property specifying to set the GPIO direction as input.
+- output-low A property specifying to set the GPIO direction as output with
+ the value low.
+- output-high A property specifying to set the GPIO direction as output with
+ the value high.
+
+Optional properties:
+- line-name: The GPIO label name. If not present the node name is used.
+
Example of two SOC GPIO banks defined as gpio-controller nodes:
qe_pio_a: gpio-controller@1400 {
@@ -123,6 +146,13 @@ Example of two SOC GPIO banks defined as gpio-controller nodes:
reg = <0x1400 0x18>;
gpio-controller;
#gpio-cells = <2>;
+
+ line_b {
+ gpio-hog;
+ gpios = <6 0>;
+ output-low;
+ line-name = "foo-bar-gpio";
+ };
};
qe_pio_e: gpio-controller@1460 {
diff --git a/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt b/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt
index 67a2e4e414a5..98d198396956 100644
--- a/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt
@@ -12,7 +12,7 @@ Required properties:
gpio_mux.
- interrupt-names : Should be the names of irq resources. Each interrupt
uses its own interrupt name, so there should be as many interrupt names
- as referenced interrups.
+ as referenced interrupts.
- interrupt-controller : Identifies the node as an interrupt controller.
- #interrupt-cells: Specifies the number of cells needed to encode an
interrupt source.
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index d85fbae451ea..c21c1313f09e 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -58,7 +58,6 @@ pattern where a GPIO is optional, the gpiod_get_optional() and
gpiod_get_index_optional() functions can be used. These functions return NULL
instead of -ENOENT if no GPIO has been assigned to the requested function:
-
struct gpio_desc *gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
@@ -68,6 +67,27 @@ instead of -ENOENT if no GPIO has been assigned to the requested function:
unsigned int index,
enum gpiod_flags flags)
+For a function using multiple GPIOs all of those can be obtained with one call:
+
+ struct gpio_descs *gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
+This function returns a struct gpio_descs which contains an array of
+descriptors:
+
+ struct gpio_descs {
+ unsigned int ndescs;
+ struct gpio_desc *desc[];
+ }
+
+The following function returns NULL instead of -ENOENT if no GPIOs have been
+assigned to the requested function:
+
+ struct gpio_descs *gpiod_get_array_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
Device-managed variants of these functions are also defined:
struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id,
@@ -82,20 +102,37 @@ Device-managed variants of these functions are also defined:
const char *con_id,
enum gpiod_flags flags)
- struct gpio_desc * devm_gpiod_get_index_optional(struct device *dev,
+ struct gpio_desc *devm_gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags)
+ struct gpio_descs *devm_gpiod_get_array(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
+ struct gpio_descs *devm_gpiod_get_array_optional(struct device *dev,
+ const char *con_id,
+ enum gpiod_flags flags)
+
A GPIO descriptor can be disposed of using the gpiod_put() function:
void gpiod_put(struct gpio_desc *desc)
-It is strictly forbidden to use a descriptor after calling this function. The
-device-managed variant is, unsurprisingly:
+For an array of GPIOs this function can be used:
+
+ void gpiod_put_array(struct gpio_descs *descs)
+
+It is strictly forbidden to use a descriptor after calling these functions.
+It is also not allowed to individually release descriptors (using gpiod_put())
+from an array acquired with gpiod_get_array().
+
+The device-managed variants are, unsurprisingly:
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
+ void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs)
+
Using GPIOs
===========
@@ -222,6 +259,26 @@ GPIOs belonging to the same bank or chip simultaneously if supported by the
corresponding chip driver. In that case a significantly improved performance
can be expected. If simultaneous setting is not possible the GPIOs will be set
sequentially.
+
+The gpiod_set_array() functions take three arguments:
+ * array_size - the number of array elements
+ * desc_array - an array of GPIO descriptors
+ * value_array - an array of values to assign to the GPIOs
+
+The descriptor array can be obtained using the gpiod_get_array() function
+or one of its variants. If the group of descriptors returned by that function
+matches the desired group of GPIOs, those GPIOs can be set by simply using
+the struct gpio_descs returned by gpiod_get_array():
+
+ struct gpio_descs *my_gpio_descs = gpiod_get_array(...);
+ gpiod_set_array(my_gpio_descs->ndescs, my_gpio_descs->desc,
+ my_gpio_values);
+
+It is also possible to set a completely arbitrary array of descriptors. The
+descriptors may be obtained using any combination of gpiod_get() and
+gpiod_get_array(). Afterwards the array of descriptors has to be setup
+manually before it can be used with gpiod_set_array().
+
Note that for optimal performance GPIOs belonging to the same chip should be
contiguous within the array of descriptors.