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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 11:48:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 11:48:03 -0700
commit3dbde57ad941c55345fd7fac0ee3f70f204b02d8 (patch)
tree237c6de64d05da3f61b9ac1724e37a5c1f014b71 /Documentation/pinctrl.txt
parenta6e6d863cf68bba886acfe47dbdc8f245cce588f (diff)
parent2207a4e1ca6a1bb126360b6d0c236af6664532f2 (diff)
Merge tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pin control changes from Linus Walleij: - A large slew of improvements of the Genric pin configuration support, and deployment in four different platforms: Rockchip, Super-H PFC, ABx500 and TZ1090. Support BIAS_BUS_HOLD, get device tree parsing and debugfs support into shape. - We also have device tree support with generic naming conventions for the generic pin configuration. - Delete the unused and confusing direct pinconf API. Now state transitions is *the* way to control pins and multiplexing. - New drivers for Rockchip, TZ1090, and TZ1090 PDC. - Two pin control states related to power management are now handled in the device core: "sleep" and "idle", removing a lot of boilerplate code in drivers. We do not yet know if this is the final word for pin PM, but it already make things a lot easier to handle. - Handle sparse GPIO ranges passing a list of disparate pins, and utilize these in the new BayTrail (x86 Atom SoC) driver. - Make the sunxi (AllWinner) driver handle external interrupts. - Make it possible for pinctrl-single to handle the case where several pins are managed by a single register, and augment it to handle sleep modes. - Cleanups and improvements for the abx500 drivers. - Move Sirf pin control drivers to their own directory, support save/restore of context and add support for the SiRFatlas6 SoC. - PMU muxing for the Dove pinctrl driver. - Finalization and support for VF610 in the i.MX6 pinctrl driver. - Smoothen out various Exynos rough edges. - Generic cleanups of various kinds. * tag 'pinctrl-for-v3.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (82 commits) pinctrl: vt8500: wmt: remove redundant dev_err call in wmt_pinctrl_probe() pinctrl: remove bindings for pinconf options needing more thought pinctrl: remove slew-rate parameter from tz1090 pinctrl: set unit for debounce time pinconfig to usec pinctrl: more clarifications for generic pull configs pinctrl: rip out the direct pinconf API pinctrl-tz1090-pdc: add TZ1090 PDC pinctrl driver pinctrl-tz1090: add TZ1090 pinctrl driver pinctrl: samsung: Staticize drvdata_list pinctrl: rockchip: Add missing irq_gc_unlock() call before return error pinctrl: abx500: rework error path pinctrl: abx500: suppress hardcoded value pinctrl: abx500: factorize code pinctrl: abx500: fix abx500_gpio_get() pinctrl: abx500: fix abx500_pin_config_set() pinctrl: abx500: Add device tree support sh-pfc: Guard DT parsing with #ifdef CONFIG_OF pinctrl: add Intel BayTrail GPIO/pinctrl support pinctrl: fix pinconf_ops::pin_config_dbg_parse_modify kerneldoc pinctrl: Staticize local symbols ... Conflicts: drivers/net/ethernet/ti/davinci_mdio.c drivers/pinctrl/Makefile
Diffstat (limited to 'Documentation/pinctrl.txt')
-rw-r--r--Documentation/pinctrl.txt39
1 files changed, 25 insertions, 14 deletions
diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt
index 447fd4cd54e..c5948c7d662 100644
--- a/Documentation/pinctrl.txt
+++ b/Documentation/pinctrl.txt
@@ -203,15 +203,8 @@ using a certain resistor value - pull up and pull down - so that the pin has a
stable value when nothing is driving the rail it is connected to, or when it's
unconnected.
-Pin configuration can be programmed either using the explicit APIs described
-immediately below, or by adding configuration entries into the mapping table;
-see section "Board/machine configuration" below.
-
-For example, a platform may do the following to pull up a pin to VDD:
-
-#include <linux/pinctrl/consumer.h>
-
-ret = pin_config_set("foo-dev", "FOO_GPIO_PIN", PLATFORM_X_PULL_UP);
+Pin configuration can be programmed by adding configuration entries into the
+mapping table; see section "Board/machine configuration" below.
The format and meaning of the configuration parameter, PLATFORM_X_PULL_UP
above, is entirely defined by the pin controller driver.
@@ -350,6 +343,23 @@ chip b:
- GPIO range : [48 .. 55]
- pin range : [64 .. 71]
+The above examples assume the mapping between the GPIOs and pins is
+linear. If the mapping is sparse or haphazard, an array of arbitrary pin
+numbers can be encoded in the range like this:
+
+static const unsigned range_pins[] = { 14, 1, 22, 17, 10, 8, 6, 2 };
+
+static struct pinctrl_gpio_range gpio_range = {
+ .name = "chip",
+ .id = 0,
+ .base = 32,
+ .pins = &range_pins,
+ .npins = ARRAY_SIZE(range_pins),
+ .gc = &chip;
+};
+
+In this case the pin_base property will be ignored.
+
When GPIO-specific functions in the pin control subsystem are called, these
ranges will be used to look up the appropriate pin controller by inspecting
and matching the pin to the pin ranges across all controllers. When a
@@ -357,9 +367,9 @@ pin controller handling the matching range is found, GPIO-specific functions
will be called on that specific pin controller.
For all functionalities dealing with pin biasing, pin muxing etc, the pin
-controller subsystem will subtract the range's .base offset from the passed
-in gpio number, and add the ranges's .pin_base offset to retrive a pin number.
-After that, the subsystem passes it on to the pin control driver, so the driver
+controller subsystem will look up the corresponding pin number from the passed
+in gpio number, and use the range's internals to retrive a pin number. After
+that, the subsystem passes it on to the pin control driver, so the driver
will get an pin number into its handled number range. Further it is also passed
the range ID value, so that the pin controller knows which range it should
deal with.
@@ -368,6 +378,7 @@ Calling pinctrl_add_gpio_range from pinctrl driver is DEPRECATED. Please see
section 2.1 of Documentation/devicetree/bindings/gpio/gpio.txt on how to bind
pinctrl and gpio drivers.
+
PINMUX interfaces
=================
@@ -1226,8 +1237,8 @@ setting up the config and muxing for the pins right before the device is
probing, nevertheless orthogonal to the GPIO subsystem.
But there are also situations where it makes sense for the GPIO subsystem
-to communicate directly with with the pinctrl subsystem, using the latter
-as a back-end. This is when the GPIO driver may call out to the functions
+to communicate directly with the pinctrl subsystem, using the latter as a
+back-end. This is when the GPIO driver may call out to the functions
described in the section "Pin control interaction with the GPIO subsystem"
above. This only involves per-pin multiplexing, and will be completely
hidden behind the gpio_*() function namespace. In this case, the driver