diff options
Diffstat (limited to 'Documentation')
22 files changed, 221 insertions, 84 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd index 3b5c3bca9186..f34e592301d1 100644 --- a/Documentation/ABI/testing/sysfs-class-mtd +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -229,6 +229,6 @@ KernelVersion: 4.1 Contact: linux-mtd@lists.infradead.org Description: For a partition, the offset of that partition from the start - of the master device in bytes. This attribute is absent on - main devices, so it can be used to distinguish between - partitions and devices that aren't partitions. + of the parent (another partition or a flash device) in bytes. + This attribute is absent on flash devices, so it can be used + to distinguish them from partitions. diff --git a/Documentation/devicetree/bindings/mtd/denali-nand.txt b/Documentation/devicetree/bindings/mtd/denali-nand.txt index e593bbeb2115..504291d2e5c2 100644 --- a/Documentation/devicetree/bindings/mtd/denali-nand.txt +++ b/Documentation/devicetree/bindings/mtd/denali-nand.txt @@ -3,10 +3,23 @@ Required properties: - compatible : should be one of the following: "altr,socfpga-denali-nand" - for Altera SOCFPGA + "socionext,uniphier-denali-nand-v5a" - for Socionext UniPhier (v5a) + "socionext,uniphier-denali-nand-v5b" - for Socionext UniPhier (v5b) - reg : should contain registers location and length for data and reg. - reg-names: Should contain the reg names "nand_data" and "denali_reg" - interrupts : The interrupt number. +Optional properties: + - nand-ecc-step-size: see nand.txt for details. If present, the value must be + 512 for "altr,socfpga-denali-nand" + 1024 for "socionext,uniphier-denali-nand-v5a" + 1024 for "socionext,uniphier-denali-nand-v5b" + - nand-ecc-strength: see nand.txt for details. Valid values are: + 8, 15 for "altr,socfpga-denali-nand" + 8, 16, 24 for "socionext,uniphier-denali-nand-v5a" + 8, 16 for "socionext,uniphier-denali-nand-v5b" + - nand-ecc-maximize: see nand.txt for details + The device tree may optionally contain sub-nodes describing partitions of the address space. See partition.txt for more detail. diff --git a/Documentation/devicetree/bindings/mtd/elm.txt b/Documentation/devicetree/bindings/mtd/elm.txt index 8c1528c421d4..59ddc61c1076 100644 --- a/Documentation/devicetree/bindings/mtd/elm.txt +++ b/Documentation/devicetree/bindings/mtd/elm.txt @@ -1,7 +1,7 @@ Error location module Required properties: -- compatible: Must be "ti,am33xx-elm" +- compatible: Must be "ti,am3352-elm" - reg: physical base address and size of the registers map. - interrupts: Interrupt number for the elm. diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index 174f68c26c1b..dd559045593d 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -5,7 +5,7 @@ the GPMC controller with a name of "nand". All timing relevant properties as well as generic gpmc child properties are explained in a separate documents - please refer to -Documentation/devicetree/bindings/bus/ti-gpmc.txt +Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt For NAND specific properties such as ECC modes or bus width, please refer to Documentation/devicetree/bindings/mtd/nand.txt diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nor.txt b/Documentation/devicetree/bindings/mtd/gpmc-nor.txt index 4828c17bb784..131d3a74d0bd 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nor.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nor.txt @@ -5,7 +5,7 @@ child nodes of the GPMC controller with a name of "nor". All timing relevant properties as well as generic GPMC child properties are explained in a separate documents. Please refer to -Documentation/devicetree/bindings/bus/ti-gpmc.txt +Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt Required properties: - bank-width: Width of NOR flash in bytes. GPMC supports 8-bit and @@ -28,7 +28,7 @@ Required properties: Optional properties: - gpmc,XXX Additional GPMC timings and settings parameters. See - Documentation/devicetree/bindings/bus/ti-gpmc.txt + Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt Optional properties for partition table parsing: - #address-cells: should be set to 1 diff --git a/Documentation/devicetree/bindings/mtd/gpmc-onenand.txt b/Documentation/devicetree/bindings/mtd/gpmc-onenand.txt index 5d8fa527c496..b6e8bfd024f4 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-onenand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-onenand.txt @@ -5,7 +5,7 @@ the GPMC controller with a name of "onenand". All timing relevant properties as well as generic gpmc child properties are explained in a separate documents - please refer to -Documentation/devicetree/bindings/bus/ti-gpmc.txt +Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt Required properties: diff --git a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt index d02acaff3c35..b289ef3c1b7e 100644 --- a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt @@ -4,7 +4,12 @@ The GPMI nand controller provides an interface to control the NAND flash chips. Required properties: - - compatible : should be "fsl,<chip>-gpmi-nand" + - compatible : should be "fsl,<chip>-gpmi-nand", chip can be: + * imx23 + * imx28 + * imx6q + * imx6sx + * imx7d - reg : should contain registers location and length for gpmi and bch. - reg-names: Should contain the reg names "gpmi-nand" and "bch" - interrupts : BCH interrupt number. @@ -13,6 +18,13 @@ Required properties: and GPMI DMA channel ID. Refer to dma.txt and fsl-mxs-dma.txt for details. - dma-names: Must be "rx-tx". + - clocks : clocks phandle and clock specifier corresponding to each clock + specified in clock-names. + - clock-names : The "gpmi_io" clock is always required. Which clocks are + exactly required depends on chip: + * imx23/imx28 : "gpmi_io" + * imx6q/sx : "gpmi_io", "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch" + * imx7d : "gpmi_io", "gpmi_bch_apb" Optional properties: - nand-on-flash-bbt: boolean to enable on flash bbt option if not diff --git a/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt new file mode 100644 index 000000000000..7328eb92a03c --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt @@ -0,0 +1,18 @@ +* MTD SPI driver for Microchip 23K256 (and similar) serial SRAM + +Required properties: +- #address-cells, #size-cells : Must be present if the device has sub-nodes + representing partitions. +- compatible : Must be one of "microchip,mchp23k256" or "microchip,mchp23lcv1024" +- reg : Chip-Select number +- spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at + +Example: + + spi-sram@0 { + #address-cells = <1>; + #size-cells = <1>; + compatible = "microchip,mchp23k256"; + reg = <0>; + spi-max-frequency = <20000000>; + }; diff --git a/Documentation/devicetree/bindings/mtd/mtk-nand.txt b/Documentation/devicetree/bindings/mtd/mtk-nand.txt index 069c192ed5c2..dbf9e054c11c 100644 --- a/Documentation/devicetree/bindings/mtd/mtk-nand.txt +++ b/Documentation/devicetree/bindings/mtd/mtk-nand.txt @@ -12,7 +12,8 @@ tree nodes. The first part of NFC is NAND Controller Interface (NFI) HW. Required NFI properties: -- compatible: Should be "mediatek,mtxxxx-nfc". +- compatible: Should be one of "mediatek,mt2701-nfc", + "mediatek,mt2712-nfc". - reg: Base physical address and size of NFI. - interrupts: Interrupts of NFI. - clocks: NFI required clocks. @@ -141,7 +142,7 @@ Example: ============== Required BCH properties: -- compatible: Should be "mediatek,mtxxxx-ecc". +- compatible: Should be one of "mediatek,mt2701-ecc", "mediatek,mt2712-ecc". - reg: Base physical address and size of ECC. - interrupts: Interrupts of ECC. - clocks: ECC required clocks. diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt index b05601600083..133f3813719c 100644 --- a/Documentation/devicetree/bindings/mtd/nand.txt +++ b/Documentation/devicetree/bindings/mtd/nand.txt @@ -21,7 +21,7 @@ Optional NAND chip properties: - nand-ecc-mode : String, operation mode of the NAND ecc mode. Supported values are: "none", "soft", "hw", "hw_syndrome", - "hw_oob_first". + "hw_oob_first", "on-die". Deprecated values: "soft_bch": use "soft" and nand-ecc-algo instead - nand-ecc-algo: string, algorithm of NAND ECC. diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt index 81a224da63be..36f3b769a626 100644 --- a/Documentation/devicetree/bindings/mtd/partition.txt +++ b/Documentation/devicetree/bindings/mtd/partition.txt @@ -1,29 +1,49 @@ -Representing flash partitions in devicetree +Flash partitions in device tree +=============================== -Partitions can be represented by sub-nodes of an mtd device. This can be used +Flash devices can be partitioned into one or more functional ranges (e.g. "boot +code", "nvram", "kernel"). + +Different devices may be partitioned in a different ways. Some may use a fixed +flash layout set at production time. Some may use on-flash table that describes +the geometry and naming/purpose of each functional region. It is also possible +to see these methods mixed. + +To assist system software in locating partitions, we allow describing which +method is used for a given flash device. To describe the method there should be +a subnode of the flash device that is named 'partitions'. It must have a +'compatible' property, which is used to identify the method to use. + +We currently only document a binding for fixed layouts. + + +Fixed Partitions +================ + +Partitions can be represented by sub-nodes of a flash device. This can be used on platforms which have strong conventions about which portions of a flash are used for what purposes, but which don't use an on-flash partition table such as RedBoot. -The partition table should be a subnode of the mtd node and should be named +The partition table should be a subnode of the flash node and should be named 'partitions'. This node should have the following property: - compatible : (required) must be "fixed-partitions" Partitions are then defined in subnodes of the partitions node. -For backwards compatibility partitions as direct subnodes of the mtd device are +For backwards compatibility partitions as direct subnodes of the flash device are supported. This use is discouraged. NOTE: also for backwards compatibility, direct subnodes that have a compatible string are not considered partitions, as they may be used for other bindings. #address-cells & #size-cells must both be present in the partitions subnode of the -mtd device. There are two valid values for both: +flash device. There are two valid values for both: <1>: for partitions that require a single 32-bit cell to represent their size/address (aka the value is below 4 GiB) <2>: for partitions that require two 32-bit cells to represent their size/address (aka the value is 4 GiB or greater). Required properties: -- reg : The partition's offset and size within the mtd bank. +- reg : The partition's offset and size within the flash Optional properties: - label : The label / name for this partition. If omitted, the label is taken diff --git a/Documentation/devicetree/bindings/net/gpmc-eth.txt b/Documentation/devicetree/bindings/net/gpmc-eth.txt index ace4a64b3695..f7da3d73ca1b 100644 --- a/Documentation/devicetree/bindings/net/gpmc-eth.txt +++ b/Documentation/devicetree/bindings/net/gpmc-eth.txt @@ -9,7 +9,7 @@ the GPMC controller with an "ethernet" name. All timing relevant properties as well as generic GPMC child properties are explained in a separate documents. Please refer to -Documentation/devicetree/bindings/bus/ti-gpmc.txt +Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt For the properties relevant to the ethernet controller connected to the GPMC refer to the binding documentation of the device. For example, the documentation @@ -43,7 +43,7 @@ Required properties: Optional properties: - gpmc,XXX Additional GPMC timings and settings parameters. See - Documentation/devicetree/bindings/bus/ti-gpmc.txt + Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt Example: diff --git a/Documentation/devicetree/bindings/pwm/pwm-meson.txt b/Documentation/devicetree/bindings/pwm/pwm-meson.txt index 5376a4468cb6..5b07bebbf6f7 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-meson.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-meson.txt @@ -2,7 +2,9 @@ Amlogic Meson PWM Controller ============================ Required properties: -- compatible: Shall contain "amlogic,meson8b-pwm" or "amlogic,meson-gxbb-pwm". +- compatible: Shall contain "amlogic,meson8b-pwm" + or "amlogic,meson-gxbb-pwm" + or "amlogic,meson-gxbb-ao-pwm" - #pwm-cells: Should be 3. See pwm.txt in this directory for a description of the cells format. diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt index 6dd040363e5e..3e6d55018d7a 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt @@ -24,7 +24,7 @@ Example: compatible = "st,stm32-timers"; reg = <0x40010000 0x400>; clocks = <&rcc 0 160>; - clock-names = "clk_int"; + clock-names = "int"; pwm { compatible = "st,stm32-pwm"; diff --git a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt index d6de64335022..7e94b802395d 100644 --- a/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt +++ b/Documentation/devicetree/bindings/pwm/renesas,pwm-rcar.txt @@ -8,6 +8,7 @@ Required Properties: - "renesas,pwm-r8a7791": for R-Car M2-W - "renesas,pwm-r8a7794": for R-Car E2 - "renesas,pwm-r8a7795": for R-Car H3 + - "renesas,pwm-r8a7796": for R-Car M3-W - reg: base address and length of the registers block for the PWM. - #pwm-cells: should be 2. See pwm.txt in this directory for a description of the cells format. diff --git a/Documentation/devicetree/bindings/rtc/brcm,brcmstb-waketimer.txt b/Documentation/devicetree/bindings/rtc/brcm,brcmstb-waketimer.txt new file mode 100644 index 000000000000..1d990bcc0baf --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/brcm,brcmstb-waketimer.txt @@ -0,0 +1,22 @@ +Broadcom STB wake-up Timer + +The Broadcom STB wake-up timer provides a 27Mhz resolution timer, with the +ability to wake up the system from low-power suspend/standby modes. + +Required properties: +- compatible : should contain "brcm,brcmstb-waketimer" +- reg : the register start and length for the WKTMR block +- interrupts : The TIMER interrupt +- interrupt-parent: The phandle to the Always-On (AON) Power Management (PM) L2 + interrupt controller node +- clocks : The phandle to the UPG fixed clock (27Mhz domain) + +Example: + +waketimer@f0411580 { + compatible = "brcm,brcmstb-waketimer"; + reg = <0xf0411580 0x14>; + interrupts = <0x3>; + interrupt-parent = <&aon_pm_l2_intc>; + clocks = <&upg_fixed>; +}; diff --git a/Documentation/devicetree/bindings/rtc/cortina,gemini.txt b/Documentation/devicetree/bindings/rtc/cortina,gemini.txt deleted file mode 100644 index 4ce4e794ddbb..000000000000 --- a/Documentation/devicetree/bindings/rtc/cortina,gemini.txt +++ /dev/null @@ -1,14 +0,0 @@ -* Cortina Systems Gemini RTC - -Gemini SoC real-time clock. - -Required properties: -- compatible : Should be "cortina,gemini-rtc" - -Examples: - -rtc@45000000 { - compatible = "cortina,gemini-rtc"; - reg = <0x45000000 0x100>; - interrupts = <17 IRQ_TYPE_LEVEL_HIGH>; -}; diff --git a/Documentation/devicetree/bindings/rtc/faraday,ftrtc010.txt b/Documentation/devicetree/bindings/rtc/faraday,ftrtc010.txt new file mode 100644 index 000000000000..e3938f5e0b6c --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/faraday,ftrtc010.txt @@ -0,0 +1,28 @@ +* Faraday Technology FTRTC010 Real Time Clock + +This RTC appears in for example the Storlink Gemini family of +SoCs. + +Required properties: +- compatible : Should be one of: + "faraday,ftrtc010" + "cortina,gemini-rtc", "faraday,ftrtc010" + +Optional properties: +- clocks: when present should contain clock references to the + PCLK and EXTCLK clocks. Faraday calls the later CLK1HZ and + says the clock should be 1 Hz, but implementers actually seem + to choose different clocks here, like Cortina who chose + 32768 Hz (a typical low-power clock). +- clock-names: should name the clocks "PCLK" and "EXTCLK" + respectively. + +Examples: + +rtc@45000000 { + compatible = "cortina,gemini-rtc"; + reg = <0x45000000 0x100>; + interrupts = <17 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&foo 0>, <&foo 1>; + clock-names = "PCLK", "EXTCLK"; +}; diff --git a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt index e2837b951237..0a4c371a9b7a 100644 --- a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt +++ b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt @@ -1,17 +1,25 @@ STM32 Real Time Clock Required properties: -- compatible: "st,stm32-rtc". +- compatible: can be either "st,stm32-rtc" or "st,stm32h7-rtc", depending on + the device is compatible with stm32(f4/f7) or stm32h7. - reg: address range of rtc register set. -- clocks: reference to the clock entry ck_rtc. +- clocks: can use up to two clocks, depending on part used: + - "rtc_ck": RTC clock source. + It is required on stm32(f4/f7) and stm32h7. + - "pclk": RTC APB interface clock. + It is not present on stm32(f4/f7). + It is required on stm32h7. +- clock-names: must be "rtc_ck" and "pclk". + It is required only on stm32h7. - interrupt-parent: phandle for the interrupt controller. - interrupts: rtc alarm interrupt. - st,syscfg: phandle for pwrcfg, mandatory to disable/enable backup domain (RTC registers) write protection. -Optional properties (to override default ck_rtc parent clock): -- assigned-clocks: reference to the ck_rtc clock entry. -- assigned-clock-parents: phandle of the new parent clock of ck_rtc. +Optional properties (to override default rtc_ck parent clock): +- assigned-clocks: reference to the rtc_ck clock entry. +- assigned-clock-parents: phandle of the new parent clock of rtc_ck. Example: @@ -25,3 +33,17 @@ Example: interrupts = <17 1>; st,syscfg = <&pwrcfg>; }; + + rtc: rtc@58004000 { + compatible = "st,stm32h7-rtc"; + reg = <0x58004000 0x400>; + clocks = <&rcc RTCAPB_CK>, <&rcc RTC_CK>; + clock-names = "pclk", "rtc_ck"; + assigned-clocks = <&rcc RTC_CK>; + assigned-clock-parents = <&rcc LSE_CK>; + interrupt-parent = <&exti>; + interrupts = <17 1>; + interrupt-names = "alarm"; + st,syscfg = <&pwrcfg>; + status = "disabled"; + }; diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 196ba17cc344..1be0b6f9e0cb 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -44,8 +44,7 @@ timeval of SO_TIMESTAMP (ms). Supports multiple types of timestamp requests. As a result, this socket option takes a bitmap of flags, not a boolean. In - err = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, (void *) val, - sizeof(val)); + err = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val)); val is an integer with any of the following bits set. Setting other bit returns EINVAL and does not change the current state. @@ -249,8 +248,7 @@ setsockopt to receive timestamps: __u32 val = SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID /* or any other flag */; - err = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, (void *) val, - sizeof(val)); + err = setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &val, sizeof(val)); 1.4 Bytestream Timestamps diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 789b27c6ec99..8fbf0aa3ba2d 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -1,4 +1,6 @@ +====================================== Pulse Width Modulation (PWM) interface +====================================== This provides an overview about the Linux PWM interface @@ -16,7 +18,7 @@ Users of the legacy PWM API use unique IDs to refer to PWM devices. Instead of referring to a PWM device via its unique ID, board setup code should instead register a static mapping that can be used to match PWM -consumers to providers, as given in the following example: +consumers to providers, as given in the following example:: static struct pwm_lookup board_pwm_lookup[] = { PWM_LOOKUP("tegra-pwm", 0, "pwm-backlight", NULL, @@ -40,9 +42,9 @@ New users should use the pwm_get() function and pass to it the consumer device or a consumer name. pwm_put() is used to free the PWM device. Managed variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist. -After being requested, a PWM has to be configured using: +After being requested, a PWM has to be configured using:: -int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state); + int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state); This API controls both the PWM period/duty_cycle config and the enable/disable state. @@ -72,11 +74,14 @@ interface is provided to use the PWMs from userspace. It is exposed at pwmchipN, where N is the base of the PWM chip. Inside the directory you will find: -npwm - The number of PWM channels this chip supports (read-only). + npwm + The number of PWM channels this chip supports (read-only). -export - Exports a PWM channel for use with sysfs (write-only). + export + Exports a PWM channel for use with sysfs (write-only). -unexport - Unexports a PWM channel from sysfs (write-only). + unexport + Unexports a PWM channel from sysfs (write-only). The PWM channels are numbered using a per-chip index from 0 to npwm-1. @@ -84,21 +89,26 @@ When a PWM channel is exported a pwmX directory will be created in the pwmchipN directory it is associated with, where X is the number of the channel that was exported. The following properties will then be available: -period - The total period of the PWM signal (read/write). - Value is in nanoseconds and is the sum of the active and inactive - time of the PWM. + period + The total period of the PWM signal (read/write). + Value is in nanoseconds and is the sum of the active and inactive + time of the PWM. -duty_cycle - The active time of the PWM signal (read/write). - Value is in nanoseconds and must be less than the period. + duty_cycle + The active time of the PWM signal (read/write). + Value is in nanoseconds and must be less than the period. -polarity - Changes the polarity of the PWM signal (read/write). - Writes to this property only work if the PWM chip supports changing - the polarity. The polarity can only be changed if the PWM is not - enabled. Value is the string "normal" or "inversed". + polarity + Changes the polarity of the PWM signal (read/write). + Writes to this property only work if the PWM chip supports changing + the polarity. The polarity can only be changed if the PWM is not + enabled. Value is the string "normal" or "inversed". -enable - Enable/disable the PWM signal (read/write). - 0 - disabled - 1 - enabled + enable + Enable/disable the PWM signal (read/write). + + - 0 - disabled + - 1 - enabled Implementing a PWM driver ------------------------- diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index ddc366026e00..c0c977445fb9 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -1,6 +1,6 @@ - - Real Time Clock (RTC) Drivers for Linux - ======================================= +======================================= +Real Time Clock (RTC) Drivers for Linux +======================================= When Linux developers talk about a "Real Time Clock", they usually mean something that tracks wall clock time and is battery backed so that it @@ -32,8 +32,8 @@ only issue an alarm up to 24 hours in the future, other hardware may be able to schedule one any time in the upcoming century. - Old PC/AT-Compatible driver: /dev/rtc - -------------------------------------- +Old PC/AT-Compatible driver: /dev/rtc +-------------------------------------- All PCs (even Alpha machines) have a Real Time Clock built into them. Usually they are built into the chipset of the computer, but some may @@ -105,8 +105,8 @@ that will be using this driver. See the code at the end of this document. (The original /dev/rtc driver was written by Paul Gortmaker.) - New portable "RTC Class" drivers: /dev/rtcN - -------------------------------------------- +New portable "RTC Class" drivers: /dev/rtcN +-------------------------------------------- Because Linux supports many non-ACPI and non-PC platforms, some of which have more than one RTC style clock, it needed a more portable solution @@ -136,35 +136,39 @@ a high functionality RTC is integrated into the SOC. That system might read the system clock from the discrete RTC, but use the integrated one for all other tasks, because of its greater functionality. -SYSFS INTERFACE +SYSFS interface --------------- The sysfs interface under /sys/class/rtc/rtcN provides access to various rtc attributes without requiring the use of ioctls. All dates and times are in the RTC's timezone, rather than in system time. -date: RTC-provided date -hctosys: 1 if the RTC provided the system time at boot via the +================ ============================================================== +date RTC-provided date +hctosys 1 if the RTC provided the system time at boot via the CONFIG_RTC_HCTOSYS kernel option, 0 otherwise -max_user_freq: The maximum interrupt rate an unprivileged user may request +max_user_freq The maximum interrupt rate an unprivileged user may request from this RTC. -name: The name of the RTC corresponding to this sysfs directory -since_epoch: The number of seconds since the epoch according to the RTC -time: RTC-provided time -wakealarm: The time at which the clock will generate a system wakeup +name The name of the RTC corresponding to this sysfs directory +since_epoch The number of seconds since the epoch according to the RTC +time RTC-provided time +wakealarm The time at which the clock will generate a system wakeup event. This is a one shot wakeup event, so must be reset - after wake if a daily wakeup is required. Format is seconds since - the epoch by default, or if there's a leading +, seconds in the - future, or if there is a leading +=, seconds ahead of the current - alarm. -offset: The amount which the rtc clock has been adjusted in firmware. + after wake if a daily wakeup is required. Format is seconds + since the epoch by default, or if there's a leading +, seconds + in the future, or if there is a leading +=, seconds ahead of + the current alarm. +offset The amount which the rtc clock has been adjusted in firmware. Visible only if the driver supports clock offset adjustment. The unit is parts per billion, i.e. The number of clock ticks which are added to or removed from the rtc's base clock per billion ticks. A positive value makes a day pass more slowly, longer, and a negative value makes a day pass more quickly. +*/nvmem The non volatile storage exported as a raw file, as described + in Documentation/nvmem/nvmem.txt +================ ============================================================== -IOCTL INTERFACE +IOCTL interface --------------- The ioctl() calls supported by /dev/rtc are also supported by the RTC class |