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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2013-06-27 23:00:25 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2013-06-27 23:00:25 -0700
commit31881d74b6dd1a6c530cff61248def4f2da38bee (patch)
treebe62420cf39192074e13b25553d172b9d5e58a33 /Documentation/devicetree/bindings/i2c
parent8855f30cd2b68012571932c7b01290c20be4508c (diff)
parent257867dc8d893690c175c1f717f91c3b6d44a63d (diff)
Merge branch 'for-next' of git://github.com/rydberg/linux into next
Pull in changes from Henrik: "a trivial MT documentation fix".
Diffstat (limited to 'Documentation/devicetree/bindings/i2c')
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt80
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-mxs.txt12
-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt2
-rw-r--r--Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.txt60
-rw-r--r--Documentation/devicetree/bindings/i2c/trivial-devices.txt2
5 files changed, 151 insertions, 5 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt
new file mode 100644
index 00000000000..1ac8ea8ade1
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt
@@ -0,0 +1,80 @@
+GPIO-based I2C Arbitration Using a Challenge & Response Mechanism
+=================================================================
+This uses GPIO lines and a challenge & response mechanism to arbitrate who is
+the master of an I2C bus in a multimaster situation.
+
+In many cases using GPIOs to arbitrate is not needed and a design can use
+the standard I2C multi-master rules. Using GPIOs is generally useful in
+the case where there is a device on the bus that has errata and/or bugs
+that makes standard multimaster mode not feasible.
+
+
+Algorithm:
+
+All masters on the bus have a 'bus claim' line which is an output that the
+others can see. These are all active low with pull-ups enabled. We'll
+describe these lines as:
+
+- OUR_CLAIM: output from us signaling to other hosts that we want the bus
+- THEIR_CLAIMS: output from others signaling that they want the bus
+
+The basic algorithm is to assert your line when you want the bus, then make
+sure that the other side doesn't want it also. A detailed explanation is best
+done with an example.
+
+Let's say we want to claim the bus. We:
+1. Assert OUR_CLAIM.
+2. Waits a little bit for the other sides to notice (slew time, say 10
+ microseconds).
+3. Check THEIR_CLAIMS. If none are asserted then the we have the bus and we are
+ done.
+4. Otherwise, wait for a few milliseconds and see if THEIR_CLAIMS are released.
+5. If not, back off, release the claim and wait for a few more milliseconds.
+6. Go back to 1 (until retry time has expired).
+
+
+Required properties:
+- compatible: i2c-arb-gpio-challenge
+- our-claim-gpio: The GPIO that we use to claim the bus.
+- their-claim-gpios: The GPIOs that the other sides use to claim the bus.
+ Note that some implementations may only support a single other master.
+- Standard I2C mux properties. See mux.txt in this directory.
+- Single I2C child bus node at reg 0. See mux.txt in this directory.
+
+Optional properties:
+- slew-delay-us: microseconds to wait for a GPIO to go high. Default is 10 us.
+- wait-retry-us: we'll attempt another claim after this many microseconds.
+ Default is 3000 us.
+- wait-free-us: we'll give up after this many microseconds. Default is 50000 us.
+
+
+Example:
+ i2c@12CA0000 {
+ compatible = "acme,some-i2c-device";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ i2c-arbitrator {
+ compatible = "i2c-arb-gpio-challenge";
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c-parent = <&{/i2c@12CA0000}>;
+
+ our-claim-gpio = <&gpf0 3 1>;
+ their-claim-gpios = <&gpe0 4 1>;
+ slew-delay-us = <10>;
+ wait-retry-us = <3000>;
+ wait-free-us = <50000>;
+
+ i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c@52 {
+ // Normal I2C device
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
index 7a3fe9e5f4c..4e1c8ac01eb 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
@@ -3,10 +3,13 @@
Required properties:
- compatible: Should be "fsl,<chip>-i2c"
- reg: Should contain registers location and length
-- interrupts: Should contain ERROR and DMA interrupts
+- interrupts: Should contain ERROR interrupt number
- clock-frequency: Desired I2C bus clock frequency in Hz.
Only 100000Hz and 400000Hz modes are supported.
-- fsl,i2c-dma-channel: APBX DMA channel for the I2C
+- dmas: DMA specifier, consisting of a phandle to DMA controller node
+ and I2C DMA channel ID.
+ Refer to dma.txt and fsl-mxs-dma.txt for details.
+- dma-names: Must be "rx-tx".
Examples:
@@ -15,7 +18,8 @@ i2c0: i2c@80058000 {
#size-cells = <0>;
compatible = "fsl,imx28-i2c";
reg = <0x80058000 2000>;
- interrupts = <111 68>;
+ interrupts = <111>;
clock-frequency = <100000>;
- fsl,i2c-dma-channel = <6>;
+ dmas = <&dma_apbx 6>;
+ dma-names = "rx-tx";
};
diff --git a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
index f98d4c5b5cc..296eb453612 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
@@ -26,7 +26,7 @@ Required for all cases except "samsung,s3c2440-hdmiphy-i2c":
- pinctrl-names: Should contain only one value - "default".
Optional properties:
- - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
+ - samsung,i2c-slave-addr: Slave address in multi-master environment. If not
specified, default value is 0.
- samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
specified, the default value in Hz is 100000.
diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.txt b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.txt
new file mode 100644
index 00000000000..ef77cc7a0e4
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.txt
@@ -0,0 +1,60 @@
+NVIDIA Tegra20/Tegra30/Tegra114 I2C controller driver.
+
+Required properties:
+- compatible : should be:
+ "nvidia,tegra114-i2c"
+ "nvidia,tegra30-i2c"
+ "nvidia,tegra20-i2c"
+ "nvidia,tegra20-i2c-dvc"
+ Details of compatible are as follows:
+ nvidia,tegra20-i2c-dvc: Tegra20 has specific I2C controller called as DVC I2C
+ controller. This only support master mode of I2C communication. Register
+ interface/offset and interrupts handling are different than generic I2C
+ controller. Driver of DVC I2C controller is only compatible with
+ "nvidia,tegra20-i2c-dvc".
+ nvidia,tegra20-i2c: Tegra20 has 4 generic I2C controller. This can support
+ master and slave mode of I2C communication. The i2c-tegra driver only
+ support master mode of I2C communication. Driver of I2C controller is
+ only compatible with "nvidia,tegra20-i2c".
+ nvidia,tegra30-i2c: Tegra30 has 5 generic I2C controller. This controller is
+ very much similar to Tegra20 I2C controller with additional feature:
+ Continue Transfer Support. This feature helps to implement M_NO_START
+ as per I2C core API transfer flags. Driver of I2C controller is
+ compatible with "nvidia,tegra30-i2c" to enable the continue transfer
+ support. This is also compatible with "nvidia,tegra20-i2c" without
+ continue transfer support.
+ nvidia,tegra114-i2c: Tegra114 has 5 generic I2C controller. This controller is
+ very much similar to Tegra30 I2C controller with some hardware
+ modification:
+ - Tegra30/Tegra20 I2C controller has 2 clock source called div-clk and
+ fast-clk. Tegra114 has only one clock source called as div-clk and
+ hence clock mechanism is changed in I2C controller.
+ - Tegra30/Tegra20 I2C controller has enabled per packet transfer by
+ default and there is no way to disable it. Tegra114 has this
+ interrupt disable by default and SW need to enable explicitly.
+ Due to above changes, Tegra114 I2C driver makes incompatible with
+ previous hardware driver. Hence, tegra114 I2C controller is compatible
+ with "nvidia,tegra114-i2c".
+- reg: Should contain I2C controller registers physical address and length.
+- interrupts: Should contain I2C controller interrupts.
+- address-cells: Address cells for I2C device address.
+- size-cells: Size of the I2C device address.
+- clocks: Clock ID as per
+ Documentation/devicetree/bindings/clock/tegra<chip-id>.txt
+ for I2C controller.
+- clock-names: Name of the clock:
+ Tegra20/Tegra30 I2C controller: "div-clk and "fast-clk".
+ Tegra114 I2C controller: "div-clk".
+
+Example:
+
+ i2c@7000c000 {
+ compatible = "nvidia,tegra20-i2c";
+ reg = <0x7000c000 0x100>;
+ interrupts = <0 38 0x04>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ clocks = <&tegra_car 12>, <&tegra_car 124>;
+ clock-names = "div-clk", "fast-clk";
+ status = "disabled";
+ };
diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 446859fcdca..ad6a73852f0 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -35,6 +35,8 @@ fsl,mc13892 MC13892: Power Management Integrated Circuit (PMIC) for i.MX35/51
fsl,mma8450 MMA8450Q: Xtrinsic Low-power, 3-axis Xtrinsic Accelerometer
fsl,mpr121 MPR121: Proximity Capacitive Touch Sensor Controller
fsl,sgtl5000 SGTL5000: Ultra Low-Power Audio Codec
+infineon,slb9635tt Infineon SLB9635 (Soft-) I2C TPM (old protocol, max 100khz)
+infineon,slb9645tt Infineon SLB9645 I2C TPM (new protocol, max 400khz)
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