diff options
Diffstat (limited to 'Documentation')
6 files changed, 96 insertions, 7 deletions
diff --git a/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt b/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt new file mode 100644 index 000000000000..81f982ccca31 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt @@ -0,0 +1,37 @@ +Broadcom iProc I2C controller + +Required properties: + +- compatible: + Must be "brcm,iproc-i2c" + +- reg: + Define the base and range of the I/O address space that contain the iProc + I2C controller registers + +- interrupts: + Should contain the I2C interrupt + +- clock-frequency: + This is the I2C bus clock. Need to be either 100000 or 400000 + +- #address-cells: + Always 1 (for I2C addresses) + +- #size-cells: + Always 0 + +Example: + i2c0: i2c@18008000 { + compatible = "brcm,iproc-i2c"; + reg = <0x18008000 0x100>; + #address-cells = <1>; + #size-cells = <0>; + interrupts = <GIC_SPI 85 IRQ_TYPE_NONE>; + clock-frequency = <100000>; + + codec: wm8750@1a { + compatible = "wlf,wm8750"; + reg = <0x1a>; + }; + }; diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt index 34a3fb6f8488..cf53d5fba20a 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt @@ -16,6 +16,9 @@ Required Properties: Optional Properties: - reset-gpios: Reference to the GPIO connected to the reset input. + - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all + children in idle state. This is necessary for example, if there are several + multiplexers on the bus and the devices behind them use same I2C addresses. Example: diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt index 1637c298a1b3..17bef9a34e50 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt @@ -4,24 +4,60 @@ Required properties: - compatible : "opencores,i2c-ocores" or "aeroflexgaisler,i2cmst" - reg : bus address start and address range size of device - interrupts : interrupt number -- clock-frequency : frequency of bus clock in Hz +- clocks : handle to the controller clock; see the note below. + Mutually exclusive with opencores,ip-clock-frequency +- opencores,ip-clock-frequency: frequency of the controller clock in Hz; + see the note below. Mutually exclusive with clocks - #address-cells : should be <1> - #size-cells : should be <0> Optional properties: +- clock-frequency : frequency of bus clock in Hz; see the note below. + Defaults to 100 KHz when the property is not specified - reg-shift : device register offsets are shifted by this value - reg-io-width : io register width in bytes (1, 2 or 4) - regstep : deprecated, use reg-shift above -Example: +Note +clock-frequency property is meant to control the bus frequency for i2c bus +drivers, but it was incorrectly used to specify i2c controller input clock +frequency. So the following rules are set to fix this situation: +- if clock-frequency is present and neither opencores,ip-clock-frequency nor + clocks are, then clock-frequency specifies i2c controller clock frequency. + This is to keep backwards compatibility with setups using old DTB. i2c bus + frequency is fixed at 100 KHz. +- if clocks is present it specifies i2c controller clock. clock-frequency + property specifies i2c bus frequency. +- if opencores,ip-clock-frequency is present it specifies i2c controller + clock frequency. clock-frequency property specifies i2c bus frequency. +Examples: + + i2c0: ocores@a0000000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "opencores,i2c-ocores"; + reg = <0xa0000000 0x8>; + interrupts = <10>; + opencores,ip-clock-frequency = <20000000>; + + reg-shift = <0>; /* 8 bit registers */ + reg-io-width = <1>; /* 8 bit read/write */ + + dummy@60 { + compatible = "dummy"; + reg = <0x60>; + }; + }; +or i2c0: ocores@a0000000 { #address-cells = <1>; #size-cells = <0>; compatible = "opencores,i2c-ocores"; reg = <0xa0000000 0x8>; interrupts = <10>; - clock-frequency = <20000000>; + clocks = <&osc>; + clock-frequency = <400000>; /* i2c bus frequency 400 KHz */ reg-shift = <0>; /* 8 bit registers */ reg-io-width = <1>; /* 8 bit read/write */ diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt index dde6c22ce91a..f0d71bc52e64 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt @@ -21,6 +21,17 @@ Required on RK3066, RK3188 : Optional properties : - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is used. + - i2c-scl-rising-time-ns : Number of nanoseconds the SCL signal takes to rise + (t(r) in I2C specification). If not specified this is assumed to be + the maximum the specification allows(1000 ns for Standard-mode, + 300 ns for Fast-mode) which might cause slightly slower communication. + - i2c-scl-falling-time-ns : Number of nanoseconds the SCL signal takes to fall + (t(f) in the I2C specification). If not specified this is assumed to + be the maximum the specification allows (300 ns) which might cause + slightly slower communication. + - i2c-sda-falling-time-ns : Number of nanoseconds the SDA signal takes to fall + (t(f) in the I2C specification). If not specified we'll use the SCL + value since they are the same in nearly all cases. Example: @@ -39,4 +50,7 @@ i2c0: i2c@2002d000 { clock-names = "i2c"; clocks = <&cru PCLK_I2C0>; + + i2c-scl-rising-time-ns = <800>; + i2c-scl-falling-time-ns = <100>; }; diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt index 4dcd88d5f7ca..aaa8325004d2 100644 --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt @@ -61,9 +61,8 @@ fsl,sgtl5000 SGTL5000: Ultra Low-Power Audio Codec gmt,g751 G751: Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface infineon,slb9635tt Infineon SLB9635 (Soft-) I2C TPM (old protocol, max 100khz) infineon,slb9645tt Infineon SLB9645 I2C TPM (new protocol, max 400khz) -isl,isl12057 Intersil ISL12057 I2C RTC Chip -isil,isl29028 (deprecated, use isl) -isl,isl29028 Intersil ISL29028 Ambient Light and Proximity Sensor +isil,isl12057 Intersil ISL12057 I2C RTC Chip +isil,isl29028 Intersil ISL29028 Ambient Light and Proximity Sensor maxim,ds1050 5 Bit Programmable, Pulse-Width Modulator maxim,max1237 Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs maxim,max6625 9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality index 4556a3eb87c4..4aae8ed15873 100644 --- a/Documentation/i2c/functionality +++ b/Documentation/i2c/functionality @@ -12,7 +12,7 @@ FUNCTIONALITY CONSTANTS ----------------------- For the most up-to-date list of functionality constants, please check -<linux/i2c.h>! +<uapi/linux/i2c.h>! I2C_FUNC_I2C Plain i2c-level commands (Pure SMBus adapters typically can not do these) |