diff options
Diffstat (limited to 'Documentation')
27 files changed, 1280 insertions, 70 deletions
diff --git a/Documentation/ABI/testing/sysfs-block-dm b/Documentation/ABI/testing/sysfs-block-dm new file mode 100644 index 000000000000..87ca5691e29b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-block-dm @@ -0,0 +1,25 @@ +What: /sys/block/dm-<num>/dm/name +Date: January 2009 +KernelVersion: 2.6.29 +Contact: dm-devel@redhat.com +Description: Device-mapper device name. + Read-only string containing mapped device name. +Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/uuid +Date: January 2009 +KernelVersion: 2.6.29 +Contact: dm-devel@redhat.com +Description: Device-mapper device UUID. + Read-only string containing DM-UUID or empty string + if DM-UUID is not set. +Users: util-linux, device-mapper udev rules + +What: /sys/block/dm-<num>/dm/suspended +Date: June 2009 +KernelVersion: 2.6.31 +Contact: dm-devel@redhat.com +Description: Device-mapper device suspend state. + Contains the value 1 while the device is suspended. + Otherwise it contains 0. Read-only attribute. +Users: util-linux, device-mapper udev rules diff --git a/Documentation/ABI/testing/sysfs-driver-samsung-laptop b/Documentation/ABI/testing/sysfs-driver-samsung-laptop index e82e7c2b8f80..678819a3f8bf 100644 --- a/Documentation/ABI/testing/sysfs-driver-samsung-laptop +++ b/Documentation/ABI/testing/sysfs-driver-samsung-laptop @@ -17,3 +17,21 @@ Description: Some Samsung laptops have different "performance levels" Specifically, not all support the "overclock" option, and it's still unknown if this value even changes anything, other than making the user feel a bit better. + +What: /sys/devices/platform/samsung/battery_life_extender +Date: December 1, 2011 +KernelVersion: 3.3 +Contact: Corentin Chary <corentin.chary@gmail.com> +Description: Max battery charge level can be modified, battery cycle + life can be extended by reducing the max battery charge + level. + 0 means normal battery mode (100% charge) + 1 means battery life extender mode (80% charge) + +What: /sys/devices/platform/samsung/usb_charge +Date: December 1, 2011 +KernelVersion: 3.3 +Contact: Corentin Chary <corentin.chary@gmail.com> +Description: Use your USB ports to charge devices, even + when your laptop is powered off. + 1 means enabled, 0 means disabled. diff --git a/Documentation/clk.txt b/Documentation/clk.txt new file mode 100644 index 000000000000..1943fae014fd --- /dev/null +++ b/Documentation/clk.txt @@ -0,0 +1,233 @@ + The Common Clk Framework + Mike Turquette <mturquette@ti.com> + +This document endeavours to explain the common clk framework details, +and how to port a platform over to this framework. It is not yet a +detailed explanation of the clock api in include/linux/clk.h, but +perhaps someday it will include that information. + + Part 1 - introduction and interface split + +The common clk framework is an interface to control the clock nodes +available on various devices today. This may come in the form of clock +gating, rate adjustment, muxing or other operations. This framework is +enabled with the CONFIG_COMMON_CLK option. + +The interface itself is divided into two halves, each shielded from the +details of its counterpart. First is the common definition of struct +clk which unifies the framework-level accounting and infrastructure that +has traditionally been duplicated across a variety of platforms. Second +is a common implementation of the clk.h api, defined in +drivers/clk/clk.c. Finally there is struct clk_ops, whose operations +are invoked by the clk api implementation. + +The second half of the interface is comprised of the hardware-specific +callbacks registered with struct clk_ops and the corresponding +hardware-specific structures needed to model a particular clock. For +the remainder of this document any reference to a callback in struct +clk_ops, such as .enable or .set_rate, implies the hardware-specific +implementation of that code. Likewise, references to struct clk_foo +serve as a convenient shorthand for the implementation of the +hardware-specific bits for the hypothetical "foo" hardware. + +Tying the two halves of this interface together is struct clk_hw, which +is defined in struct clk_foo and pointed to within struct clk. This +allows easy for navigation between the two discrete halves of the common +clock interface. + + Part 2 - common data structures and api + +Below is the common struct clk definition from +include/linux/clk-private.h, modified for brevity: + + struct clk { + const char *name; + const struct clk_ops *ops; + struct clk_hw *hw; + char **parent_names; + struct clk **parents; + struct clk *parent; + struct hlist_head children; + struct hlist_node child_node; + ... + }; + +The members above make up the core of the clk tree topology. The clk +api itself defines several driver-facing functions which operate on +struct clk. That api is documented in include/linux/clk.h. + +Platforms and devices utilizing the common struct clk use the struct +clk_ops pointer in struct clk to perform the hardware-specific parts of +the operations defined in clk.h: + + struct clk_ops { + int (*prepare)(struct clk_hw *hw); + void (*unprepare)(struct clk_hw *hw); + int (*enable)(struct clk_hw *hw); + void (*disable)(struct clk_hw *hw); + int (*is_enabled)(struct clk_hw *hw); + unsigned long (*recalc_rate)(struct clk_hw *hw, + unsigned long parent_rate); + long (*round_rate)(struct clk_hw *hw, unsigned long, + unsigned long *); + int (*set_parent)(struct clk_hw *hw, u8 index); + u8 (*get_parent)(struct clk_hw *hw); + int (*set_rate)(struct clk_hw *hw, unsigned long); + void (*init)(struct clk_hw *hw); + }; + + Part 3 - hardware clk implementations + +The strength of the common struct clk comes from its .ops and .hw pointers +which abstract the details of struct clk from the hardware-specific bits, and +vice versa. To illustrate consider the simple gateable clk implementation in +drivers/clk/clk-gate.c: + +struct clk_gate { + struct clk_hw hw; + void __iomem *reg; + u8 bit_idx; + ... +}; + +struct clk_gate contains struct clk_hw hw as well as hardware-specific +knowledge about which register and bit controls this clk's gating. +Nothing about clock topology or accounting, such as enable_count or +notifier_count, is needed here. That is all handled by the common +framework code and struct clk. + +Let's walk through enabling this clk from driver code: + + struct clk *clk; + clk = clk_get(NULL, "my_gateable_clk"); + + clk_prepare(clk); + clk_enable(clk); + +The call graph for clk_enable is very simple: + +clk_enable(clk); + clk->ops->enable(clk->hw); + [resolves to...] + clk_gate_enable(hw); + [resolves struct clk gate with to_clk_gate(hw)] + clk_gate_set_bit(gate); + +And the definition of clk_gate_set_bit: + +static void clk_gate_set_bit(struct clk_gate *gate) +{ + u32 reg; + + reg = __raw_readl(gate->reg); + reg |= BIT(gate->bit_idx); + writel(reg, gate->reg); +} + +Note that to_clk_gate is defined as: + +#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, clk) + +This pattern of abstraction is used for every clock hardware +representation. + + Part 4 - supporting your own clk hardware + +When implementing support for a new type of clock it only necessary to +include the following header: + +#include <linux/clk-provider.h> + +include/linux/clk.h is included within that header and clk-private.h +must never be included from the code which implements the operations for +a clock. More on that below in Part 5. + +To construct a clk hardware structure for your platform you must define +the following: + +struct clk_foo { + struct clk_hw hw; + ... hardware specific data goes here ... +}; + +To take advantage of your data you'll need to support valid operations +for your clk: + +struct clk_ops clk_foo_ops { + .enable = &clk_foo_enable; + .disable = &clk_foo_disable; +}; + +Implement the above functions using container_of: + +#define to_clk_foo(_hw) container_of(_hw, struct clk_foo, hw) + +int clk_foo_enable(struct clk_hw *hw) +{ + struct clk_foo *foo; + + foo = to_clk_foo(hw); + + ... perform magic on foo ... + + return 0; +}; + +Below is a matrix detailing which clk_ops are mandatory based upon the +hardware capbilities of that clock. A cell marked as "y" means +mandatory, a cell marked as "n" implies that either including that +callback is invalid or otherwise uneccesary. Empty cells are either +optional or must be evaluated on a case-by-case basis. + + clock hardware characteristics + ----------------------------------------------------------- + | gate | change rate | single parent | multiplexer | root | + |------|-------------|---------------|-------------|------| +.prepare | | | | | | +.unprepare | | | | | | + | | | | | | +.enable | y | | | | | +.disable | y | | | | | +.is_enabled | y | | | | | + | | | | | | +.recalc_rate | | y | | | | +.round_rate | | y | | | | +.set_rate | | y | | | | + | | | | | | +.set_parent | | | n | y | n | +.get_parent | | | n | y | n | + | | | | | | +.init | | | | | | + ----------------------------------------------------------- + +Finally, register your clock at run-time with a hardware-specific +registration function. This function simply populates struct clk_foo's +data and then passes the common struct clk parameters to the framework +with a call to: + +clk_register(...) + +See the basic clock types in drivers/clk/clk-*.c for examples. + + Part 5 - static initialization of clock data + +For platforms with many clocks (often numbering into the hundreds) it +may be desirable to statically initialize some clock data. This +presents a problem since the definition of struct clk should be hidden +from everyone except for the clock core in drivers/clk/clk.c. + +To get around this problem struct clk's definition is exposed in +include/linux/clk-private.h along with some macros for more easily +initializing instances of the basic clock types. These clocks must +still be initialized with the common clock framework via a call to +__clk_init. + +clk-private.h must NEVER be included by code which implements struct +clk_ops callbacks, nor must it be included by any logic which pokes +around inside of struct clk at run-time. To do so is a layering +violation. + +To better enforce this policy, always follow this simple rule: any +statically initialized clock data MUST be defined in a separate file +from the logic that implements its ops. Basically separate the logic +from the data and all is well. diff --git a/Documentation/device-mapper/thin-provisioning.txt b/Documentation/device-mapper/thin-provisioning.txt index 1ff044d87ca4..3370bc4d7b98 100644 --- a/Documentation/device-mapper/thin-provisioning.txt +++ b/Documentation/device-mapper/thin-provisioning.txt @@ -75,10 +75,12 @@ less sharing than average you'll need a larger-than-average metadata device. As a guide, we suggest you calculate the number of bytes to use in the metadata device as 48 * $data_dev_size / $data_block_size but round it up -to 2MB if the answer is smaller. The largest size supported is 16GB. +to 2MB if the answer is smaller. If you're creating large numbers of +snapshots which are recording large amounts of change, you may find you +need to increase this. -If you're creating large numbers of snapshots which are recording large -amounts of change, you may need find you need to increase this. +The largest size supported is 16GB: If the device is larger, +a warning will be issued and the excess space will not be used. Reloading a pool table ---------------------- @@ -167,6 +169,38 @@ ii) Using an internal snapshot. dmsetup create snap --table "0 2097152 thin /dev/mapper/pool 1" +External snapshots +------------------ + +You can use an external _read only_ device as an origin for a +thinly-provisioned volume. Any read to an unprovisioned area of the +thin device will be passed through to the origin. Writes trigger +the allocation of new blocks as usual. + +One use case for this is VM hosts that want to run guests on +thinly-provisioned volumes but have the base image on another device +(possibly shared between many VMs). + +You must not write to the origin device if you use this technique! +Of course, you may write to the thin device and take internal snapshots +of the thin volume. + +i) Creating a snapshot of an external device + + This is the same as creating a thin device. + You don't mention the origin at this stage. + + dmsetup message /dev/mapper/pool 0 "create_thin 0" + +ii) Using a snapshot of an external device. + + Append an extra parameter to the thin target specifying the origin: + + dmsetup create snap --table "0 2097152 thin /dev/mapper/pool 0 /dev/image" + + N.B. All descendants (internal snapshots) of this snapshot require the + same extra origin parameter. + Deactivation ------------ @@ -189,7 +223,13 @@ i) Constructor <low water mark (blocks)> [<number of feature args> [<arg>]*] Optional feature arguments: - - 'skip_block_zeroing': skips the zeroing of newly-provisioned blocks. + + skip_block_zeroing: Skip the zeroing of newly-provisioned blocks. + + ignore_discard: Disable discard support. + + no_discard_passdown: Don't pass discards down to the underlying + data device, but just remove the mapping. Data block size must be between 64KB (128 sectors) and 1GB (2097152 sectors) inclusive. @@ -237,16 +277,6 @@ iii) Messages Deletes a thin device. Irreversible. - trim <dev id> <new size in sectors> - - Delete mappings from the end of a thin device. Irreversible. - You might want to use this if you're reducing the size of - your thinly-provisioned device. In many cases, due to the - sharing of blocks between devices, it is not possible to - determine in advance how much space 'trim' will release. (In - future a userspace tool might be able to perform this - calculation.) - set_transaction_id <current id> <new id> Userland volume managers, such as LVM, need a way to @@ -262,7 +292,7 @@ iii) Messages i) Constructor - thin <pool dev> <dev id> + thin <pool dev> <dev id> [<external origin dev>] pool dev: the thin-pool device, e.g. /dev/mapper/my_pool or 253:0 @@ -271,6 +301,11 @@ i) Constructor the internal device identifier of the device to be activated. + external origin dev: + an optional block device outside the pool to be treated as a + read-only snapshot origin: reads to unprovisioned areas of the + thin target will be mapped to this device. + The pool doesn't store any size against the thin devices. If you load a thin target that is smaller than you've been using previously, then you'll have no access to blocks mapped beyond the end. If you diff --git a/Documentation/device-mapper/verity.txt b/Documentation/device-mapper/verity.txt new file mode 100644 index 000000000000..32e48797a14f --- /dev/null +++ b/Documentation/device-mapper/verity.txt @@ -0,0 +1,194 @@ +dm-verity +========== + +Device-Mapper's "verity" target provides transparent integrity checking of +block devices using a cryptographic digest provided by the kernel crypto API. +This target is read-only. + +Construction Parameters +======================= + <version> <dev> <hash_dev> <hash_start> + <data_block_size> <hash_block_size> + <num_data_blocks> <hash_start_block> + <algorithm> <digest> <salt> + +<version> + This is the version number of the on-disk format. + + 0 is the original format used in the Chromium OS. + The salt is appended when hashing, digests are stored continuously and + the rest of the block is padded with zeros. + + 1 is the current format that should be used for new devices. + The salt is prepended when hashing and each digest is + padded with zeros to the power of two. + +<dev> + This is the device containing the data the integrity of which needs to be + checked. It may be specified as a path, like /dev/sdaX, or a device number, + <major>:<minor>. + +<hash_dev> + This is the device that that supplies the hash tree data. It may be + specified similarly to the device path and may be the same device. If the + same device is used, the hash_start should be outside of the dm-verity + configured device size. + +<data_block_size> + The block size on a data device. Each block corresponds to one digest on + the hash device. + +<hash_block_size> + The size of a hash block. + +<num_data_blocks> + The number of data blocks on the data device. Additional blocks are + inaccessible. You can place hashes to the same partition as data, in this + case hashes are placed after <num_data_blocks>. + +<hash_start_block> + This is the offset, in <hash_block_size>-blocks, from the start of hash_dev + to the root block of the hash tree. + +<algorithm> + The cryptographic hash algorithm used for this device. This should + be the name of the algorithm, like "sha1". + +<digest> + The hexadecimal encoding of the cryptographic hash of the root hash block + and the salt. This hash should be trusted as there is no other authenticity + beyond this point. + +<salt> + The hexadecimal encoding of the salt value. + +Theory of operation +=================== + +dm-verity is meant to be setup as part of a verified boot path. This +may be anything ranging from a boot using tboot or trustedgrub to just +booting from a known-good device (like a USB drive or CD). + +When a dm-verity device is configured, it is expected that the caller +has been authenticated in some way (cryptographic signatures, etc). +After instantiation, all hashes will be verified on-demand during +disk access. If they cannot be verified up to the root node of the +tree, the root hash, then the I/O will fail. This should identify +tampering with any data on the device and the hash data. + +Cryptographic hashes are used to assert the integrity of the device on a +per-block basis. This allows for a lightweight hash computation on first read +into the page cache. Block hashes are stored linearly-aligned to the nearest +block the size of a page. + +Hash Tree +--------- + +Each node in the tree is a cryptographic hash. If it is a leaf node, the hash +is of some block data on disk. If it is an intermediary node, then the hash is +of a number of child nodes. + +Each entry in the tree is a collection of neighboring nodes that fit in one +block. The number is determined based on block_size and the size of the +selected cryptographic digest algorithm. The hashes are linearly-ordered in +this entry and any unaligned trailing space is ignored but included when +calculating the parent node. + +The tree looks something like: + +alg = sha256, num_blocks = 32768, block_size = 4096 + + [ root ] + / . . . \ + [entry_0] [entry_1] + / . . . \ . . . \ + [entry_0_0] . . . [entry_0_127] . . . . [entry_1_127] + / ... \ / . . . \ / \ + blk_0 ... blk_127 blk_16256 blk_16383 blk_32640 . . . blk_32767 + + +On-disk format +============== + +Below is the recommended on-disk format. The verity kernel code does not +read the on-disk header. It only reads the hash blocks which directly +follow the header. It is expected that a user-space tool will verify the +integrity of the verity_header and then call dmsetup with the correct +parameters. Alternatively, the header can be omitted and the dmsetup +parameters can be passed via the kernel command-line in a rooted chain +of trust where the command-line is verified. + +The on-disk format is especially useful in cases where the hash blocks +are on a separate partition. The magic number allows easy identification +of the partition contents. Alternatively, the hash blocks can be stored +in the same partition as the data to be verified. In such a configuration +the filesystem on the partition would be sized a little smaller than +the full-partition, leaving room for the hash blocks. + +struct superblock { + uint8_t signature[8] + "verity\0\0"; + + uint8_t version; + 1 - current format + + uint8_t data_block_bits; + log2(data block size) + + uint8_t hash_block_bits; + log2(hash block size) + + uint8_t pad1[1]; + zero padding + + uint16_t salt_size; + big-endian salt size + + uint8_t pad2[2]; + zero padding + + uint32_t data_blocks_hi; + big-endian high 32 bits of the 64-bit number of data blocks + + uint32_t data_blocks_lo; + big-endian low 32 bits of the 64-bit number of data blocks + + uint8_t algorithm[16]; + cryptographic algorithm + + uint8_t salt[384]; + salt (the salt size is specified above) + + uint8_t pad3[88]; + zero padding to 512-byte boundary +} + +Directly following the header (and with sector number padded to the next hash +block boundary) are the hash blocks which are stored a depth at a time +(starting from the root), sorted in order of increasing index. + +Status +====== +V (for Valid) is returned if every check performed so far was valid. +If any check failed, C (for Corruption) is returned. + +Example +======= + +Setup a device: + dmsetup create vroot --table \ + "0 2097152 "\ + "verity 1 /dev/sda1 /dev/sda2 4096 4096 2097152 1 "\ + "4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 "\ + "1234000000000000000000000000000000000000000000000000000000000000" + +A command line tool veritysetup is available to compute or verify +the hash tree or activate the kernel driver. This is available from +the LVM2 upstream repository and may be supplied as a package called +device-mapper-verity-tools: + git://sources.redhat.com/git/lvm2 + http://sourceware.org/git/?p=lvm2.git + http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/verity?cvsroot=lvm2 + +veritysetup -a vroot /dev/sda1 /dev/sda2 \ + 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt index 1aeaf6f2a1ba..ecc81e368715 100644 --- a/Documentation/devicetree/bindings/arm/atmel-at91.txt +++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt @@ -30,3 +30,63 @@ One interrupt per TC channel in a TC block: reg = <0xfffdc000 0x100>; interrupts = <26 4 27 4 28 4>; }; + +RSTC Reset Controller required properties: +- compatible: Should be "atmel,<chip>-rstc". + <chip> can be "at91sam9260" or "at91sam9g45" +- reg: Should contain registers location and length + +Example: + + rstc@fffffd00 { + compatible = "atmel,at91sam9260-rstc"; + reg = <0xfffffd00 0x10>; + }; + +RAMC SDRAM/DDR Controller required properties: +- compatible: Should be "atmel,at91sam9260-sdramc", + "atmel,at91sam9g45-ddramc", +- reg: Should contain registers location and length + For at91sam9263 and at91sam9g45 you must specify 2 entries. + +Examples: + + ramc0: ramc@ffffe800 { + compatible = "atmel,at91sam9g45-ddramc"; + reg = <0xffffe800 0x200>; + }; + + ramc0: ramc@ffffe400 { + compatible = "atmel,at91sam9g45-ddramc"; + reg = <0xffffe400 0x200 + 0xffffe600 0x200>; + }; + +SHDWC Shutdown Controller + +required properties: +- compatible: Should be "atmel,<chip>-shdwc". + <chip> can be "at91sam9260", "at91sam9rl" or "at91sam9x5". +- reg: Should contain registers location and length + +optional properties: +- atmel,wakeup-mode: String, operation mode of the wakeup mode. + Supported values are: "none", "high", "low", "any". +- atmel,wakeup-counter: Counter on Wake-up 0 (between 0x0 and 0xf). + +optional at91sam9260 properties: +- atmel,wakeup-rtt-timer: boolean to enable Real-time Timer Wake-up. + +optional at91sam9rl properties: +- atmel,wakeup-rtc-timer: boolean to enable Real-time Clock Wake-up. +- atmel,wakeup-rtt-timer: boolean to enable Real-time Timer Wake-up. + +optional at91sam9x5 properties: +- atmel,wakeup-rtc-timer: boolean to enable Real-time Clock Wake-up. + +Example: + + rstc@fffffd00 { + compatible = "atmel,at91sam9260-rstc"; + reg = <0xfffffd00 0x10>; + }; diff --git a/Documentation/devicetree/bindings/arm/atmel-pmc.txt b/Documentation/devicetree/bindings/arm/atmel-pmc.txt new file mode 100644 index 000000000000..389bed5056e8 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/atmel-pmc.txt @@ -0,0 +1,11 @@ +* Power Management Controller (PMC) + +Required properties: +- compatible: Should be "atmel,at91rm9200-pmc" +- reg: Should contain PMC registers location and length + +Examples: + pmc: pmc@fffffc00 { + compatible = "atmel,at91rm9200-pmc"; + reg = <0xfffffc00 0x100>; + }; diff --git a/Documentation/devicetree/bindings/arm/spear.txt b/Documentation/devicetree/bindings/arm/spear.txt new file mode 100644 index 000000000000..f8e54f092328 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/spear.txt @@ -0,0 +1,8 @@ +ST SPEAr Platforms Device Tree Bindings +--------------------------------------- + +Boards with the ST SPEAr600 SoC shall have the following properties: + +Required root node property: + +compatible = "st,spear600"; diff --git a/Documentation/devicetree/bindings/gpio/gpio-omap.txt b/Documentation/devicetree/bindings/gpio/gpio-omap.txt new file mode 100644 index 000000000000..bff51a2fee1e --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-omap.txt @@ -0,0 +1,36 @@ +OMAP GPIO controller bindings + +Required properties: +- compatible: + - "ti,omap2-gpio" for OMAP2 controllers + - "ti,omap3-gpio" for OMAP3 controllers + - "ti,omap4-gpio" for OMAP4 controllers +- #gpio-cells : Should be two. + - first cell is the pin number + - second cell is used to specify optional parameters (unused) +- gpio-controller : Marks the device node as a GPIO controller. +- #interrupt-cells : Should be 2. +- interrupt-controller: Mark the device node as an interrupt controller + The first cell is the GPIO number. + The second cell is used to specify flags: + bits[3:0] trigger type and level flags: + 1 = low-to-high edge triggered. + 2 = high-to-low edge triggered. + 4 = active high level-sensitive. + 8 = active low level-sensitive. + +OMAP specific properties: +- ti,hwmods: Name of the hwmod associated to the GPIO: + "gpio<X>", <X> being the 1-based instance number from the HW spec + + +Example: + +gpio4: gpio4 { + compatible = "ti,omap4-gpio"; + ti,hwmods = "gpio4"; + #gpio-cells = <2>; + gpio-controller; + #interrupt-cells = <2>; + interrupt-controller; +}; diff --git a/Documentation/devicetree/bindings/gpio/gpio-twl4030.txt b/Documentation/devicetree/bindings/gpio/gpio-twl4030.txt new file mode 100644 index 000000000000..16695d9cf1e8 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-twl4030.txt @@ -0,0 +1,23 @@ +twl4030 GPIO controller bindings + +Required properties: +- compatible: + - "ti,twl4030-gpio" for twl4030 GPIO controller +- #gpio-cells : Should be two. + - first cell is the pin number + - second cell is used to specify optional parameters (unused) +- gpi |