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-rw-r--r--Documentation/devicetree/bindings/dma/rcar-audmapp.txt6
-rw-r--r--Documentation/devicetree/bindings/input/atmel,maxtouch.txt11
-rw-r--r--Documentation/devicetree/bindings/interrupt-controller/interrupts.txt12
-rw-r--r--Documentation/devicetree/bindings/mfd/tc3589x.txt107
-rw-r--r--Documentation/devicetree/bindings/mtd/gpmc-nand.txt2
-rw-r--r--Documentation/devicetree/bindings/net/stmmac.txt4
-rw-r--r--Documentation/devicetree/bindings/pci/designware-pcie.txt4
-rw-r--r--Documentation/devicetree/bindings/pci/ti-pci.txt59
-rw-r--r--Documentation/devicetree/bindings/pinctrl/qcom,apq8064-pinctrl.txt2
-rw-r--r--Documentation/devicetree/bindings/regulator/tps65090.txt4
-rw-r--r--Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt2
-rw-r--r--Documentation/devicetree/bindings/sound/rockchip-i2s.txt2
-rw-r--r--Documentation/devicetree/bindings/spi/spi-rockchip.txt8
-rw-r--r--Documentation/devicetree/bindings/staging/imx-drm/ldb.txt15
-rw-r--r--Documentation/devicetree/bindings/usb/mxs-phy.txt1
-rw-r--r--Documentation/devicetree/bindings/video/analog-tv-connector.txt4
-rw-r--r--Documentation/devicetree/of_selftest.txt211
17 files changed, 432 insertions, 22 deletions
diff --git a/Documentation/devicetree/bindings/dma/rcar-audmapp.txt b/Documentation/devicetree/bindings/dma/rcar-audmapp.txt
index 9f1d750d76de..61bca509d7b9 100644
--- a/Documentation/devicetree/bindings/dma/rcar-audmapp.txt
+++ b/Documentation/devicetree/bindings/dma/rcar-audmapp.txt
@@ -16,9 +16,9 @@ Example:
* DMA client
Required properties:
-- dmas: a list of <[DMA multiplexer phandle] [SRS/DRS value]> pairs,
- where SRS/DRS values are fixed handles, specified in the SoC
- manual as the value that would be written into the PDMACHCR.
+- dmas: a list of <[DMA multiplexer phandle] [SRS << 8 | DRS]> pairs.
+ where SRS/DRS are specified in the SoC manual.
+ It will be written into PDMACHCR as high 16-bit parts.
- dma-names: a list of DMA channel names, one per "dmas" entry
Example:
diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
index baef432e8369..1852906517ab 100644
--- a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
+++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
@@ -11,10 +11,17 @@ Required properties:
Optional properties for main touchpad device:
-- linux,gpio-keymap: An array of up to 4 entries indicating the Linux
- keycode generated by each GPIO. Linux keycodes are defined in
+- linux,gpio-keymap: When enabled, the SPT_GPIOPWN_T19 object sends messages
+ on GPIO bit changes. An array of up to 8 entries can be provided
+ indicating the Linux keycode mapped to each bit of the status byte,
+ starting at the LSB. Linux keycodes are defined in
<dt-bindings/input/input.h>.
+ Note: the numbering of the GPIOs and the bit they start at varies between
+ maXTouch devices. You must either refer to the documentation, or
+ experiment to determine which bit corresponds to which input. Use
+ KEY_RESERVED for unused padding values.
+
Example:
touch@4b {
diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
index 1486497a24c1..ce6a1a072028 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
@@ -4,11 +4,13 @@ Specifying interrupt information for devices
1) Interrupt client nodes
-------------------------
-Nodes that describe devices which generate interrupts must contain an either an
-"interrupts" property or an "interrupts-extended" property. These properties
-contain a list of interrupt specifiers, one per output interrupt. The format of
-the interrupt specifier is determined by the interrupt controller to which the
-interrupts are routed; see section 2 below for details.
+Nodes that describe devices which generate interrupts must contain an
+"interrupts" property, an "interrupts-extended" property, or both. If both are
+present, the latter should take precedence; the former may be provided simply
+for compatibility with software that does not recognize the latter. These
+properties contain a list of interrupt specifiers, one per output interrupt. The
+format of the interrupt specifier is determined by the interrupt controller to
+which the interrupts are routed; see section 2 below for details.
Example:
interrupt-parent = <&intc1>;
diff --git a/Documentation/devicetree/bindings/mfd/tc3589x.txt b/Documentation/devicetree/bindings/mfd/tc3589x.txt
new file mode 100644
index 000000000000..6fcedba46ae9
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/tc3589x.txt
@@ -0,0 +1,107 @@
+* Toshiba TC3589x multi-purpose expander
+
+The Toshiba TC3589x series are I2C-based MFD devices which may expose the
+following built-in devices: gpio, keypad, rotator (vibrator), PWM (for
+e.g. LEDs or vibrators) The included models are:
+
+- TC35890
+- TC35892
+- TC35893
+- TC35894
+- TC35895
+- TC35896
+
+Required properties:
+ - compatible : must be "toshiba,tc35890", "toshiba,tc35892", "toshiba,tc35893",
+ "toshiba,tc35894", "toshiba,tc35895" or "toshiba,tc35896"
+ - reg : I2C address of the device
+ - interrupt-parent : specifies which IRQ controller we're connected to
+ - interrupts : the interrupt on the parent the controller is connected to
+ - interrupt-controller : marks the device node as an interrupt controller
+ - #interrupt-cells : should be <1>, the first cell is the IRQ offset on this
+ TC3589x interrupt controller.
+
+Optional nodes:
+
+- GPIO
+ This GPIO module inside the TC3589x has 24 (TC35890, TC35892) or 20
+ (other models) GPIO lines.
+ - compatible : must be "toshiba,tc3589x-gpio"
+ - interrupts : interrupt on the parent, which must be the tc3589x MFD device
+ - interrupt-controller : marks the device node as an interrupt controller
+ - #interrupt-cells : should be <2>, the first cell is the IRQ offset on this
+ TC3589x GPIO interrupt controller, the second cell is the interrupt flags
+ in accordance with <dt-bindings/interrupt-controller/irq.h>. The following
+ flags are valid:
+ - IRQ_TYPE_LEVEL_LOW
+ - IRQ_TYPE_LEVEL_HIGH
+ - IRQ_TYPE_EDGE_RISING
+ - IRQ_TYPE_EDGE_FALLING
+ - IRQ_TYPE_EDGE_BOTH
+ - gpio-controller : marks the device node as a GPIO controller
+ - #gpio-cells : should be <2>, the first cell is the GPIO offset on this
+ GPIO controller, the second cell is the flags.
+
+- Keypad
+ This keypad is the same on all variants, supporting up to 96 different
+ keys. The linux-specific properties are modeled on those already existing
+ in other input drivers.
+ - compatible : must be "toshiba,tc3589x-keypad"
+ - debounce-delay-ms : debounce interval in milliseconds
+ - keypad,num-rows : number of rows in the matrix, see
+ bindings/input/matrix-keymap.txt
+ - keypad,num-columns : number of columns in the matrix, see
+ bindings/input/matrix-keymap.txt
+ - linux,keymap: the definition can be found in
+ bindings/input/matrix-keymap.txt
+ - linux,no-autorepeat: do no enable autorepeat feature.
+ - linux,wakeup: use any event on keypad as wakeup event.
+
+Example:
+
+tc35893@44 {
+ compatible = "toshiba,tc35893";
+ reg = <0x44>;
+ interrupt-parent = <&gpio6>;
+ interrupts = <26 IRQ_TYPE_EDGE_RISING>;
+
+ interrupt-controller;
+ #interrupt-cells = <1>;
+
+ tc3589x_gpio {
+ compatible = "toshiba,tc3589x-gpio";
+ interrupts = <0>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+ tc3589x_keypad {
+ compatible = "toshiba,tc3589x-keypad";
+ interrupts = <6>;
+ debounce-delay-ms = <4>;
+ keypad,num-columns = <8>;
+ keypad,num-rows = <8>;
+ linux,no-autorepeat;
+ linux,wakeup;
+ linux,keymap = <0x0301006b
+ 0x04010066
+ 0x06040072
+ 0x040200d7
+ 0x0303006a
+ 0x0205000e
+ 0x0607008b
+ 0x0500001c
+ 0x0403000b
+ 0x03040034
+ 0x05020067
+ 0x0305006c
+ 0x040500e7
+ 0x0005009e
+ 0x06020073
+ 0x01030039
+ 0x07060069
+ 0x050500d9>;
+ };
+};
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index 65f4f7c43136..ee654e95d8ad 100644
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -22,7 +22,7 @@ Optional properties:
width of 8 is assumed.
- ti,nand-ecc-opt: A string setting the ECC layout to use. One of:
- "sw" <deprecated> use "ham1" instead
+ "sw" 1-bit Hamming ecc code via software
"hw" <deprecated> use "ham1" instead
"hw-romcode" <deprecated> use "ham1" instead
"ham1" 1-bit Hamming ecc code
diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index 9b03c57563a4..e45ac3f926b1 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,10 @@ Optional properties:
further clocks may be specified in derived bindings.
- clock-names: One name for each entry in the clocks property, the
first one should be "stmmaceth".
+- clk_ptp_ref: this is the PTP reference clock; in case of the PTP is
+ available this clock is used for programming the Timestamp Addend Register.
+ If not passed then the system clock will be used and this is fine on some
+ platforms.
Examples:
diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
index d0d15ee42834..ed0d9b9fff2b 100644
--- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
@@ -2,6 +2,10 @@
Required properties:
- compatible: should contain "snps,dw-pcie" to identify the core.
+- reg: Should contain the configuration address space.
+- reg-names: Must be "config" for the PCIe configuration space.
+ (The old way of getting the configuration address space from "ranges"
+ is deprecated and should be avoided.)
- #address-cells: set to <3>
- #size-cells: set to <2>
- device_type: set to "pci"
diff --git a/Documentation/devicetree/bindings/pci/ti-pci.txt b/Documentation/devicetree/bindings/pci/ti-pci.txt
new file mode 100644
index 000000000000..3d217911b313
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/ti-pci.txt
@@ -0,0 +1,59 @@
+TI PCI Controllers
+
+PCIe Designware Controller
+ - compatible: Should be "ti,dra7-pcie""
+ - reg : Two register ranges as listed in the reg-names property
+ - reg-names : The first entry must be "ti-conf" for the TI specific registers
+ The second entry must be "rc-dbics" for the designware pcie
+ registers
+ The third entry must be "config" for the PCIe configuration space
+ - phys : list of PHY specifiers (used by generic PHY framework)
+ - phy-names : must be "pcie-phy0", "pcie-phy1", "pcie-phyN".. based on the
+ number of PHYs as specified in *phys* property.
+ - ti,hwmods : Name of the hwmod associated to the pcie, "pcie<X>",
+ where <X> is the instance number of the pcie from the HW spec.
+ - interrupts : Two interrupt entries must be specified. The first one is for
+ main interrupt line and the second for MSI interrupt line.
+ - #address-cells,
+ #size-cells,
+ #interrupt-cells,
+ device_type,
+ ranges,
+ num-lanes,
+ interrupt-map-mask,
+ interrupt-map : as specified in ../designware-pcie.txt
+
+Example:
+axi {
+ compatible = "simple-bus";
+ #size-cells = <1>;
+ #address-cells = <1>;
+ ranges = <0x51000000 0x51000000 0x3000
+ 0x0 0x20000000 0x10000000>;
+ pcie@51000000 {
+ compatible = "ti,dra7-pcie";
+ reg = <0x51000000 0x2000>, <0x51002000 0x14c>, <0x1000 0x2000>;
+ reg-names = "rc_dbics", "ti_conf", "config";
+ interrupts = <0 232 0x4>, <0 233 0x4>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges = <0x81000000 0 0 0x03000 0 0x00010000
+ 0x82000000 0 0x20013000 0x13000 0 0xffed000>;
+ #interrupt-cells = <1>;
+ num-lanes = <1>;
+ ti,hwmods = "pcie1";
+ phys = <&pcie1_phy>;
+ phy-names = "pcie-phy0";
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie_intc 1>,
+ <0 0 0 2 &pcie_intc 2>,
+ <0 0 0 3 &pcie_intc 3>,
+ <0 0 0 4 &pcie_intc 4>;
+ pcie_intc: interrupt-controller {
+ interrupt-controller;
+ #address-cells = <0>;
+ #interrupt-cells = <1>;
+ };
+ };
+};
diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,apq8064-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/qcom,apq8064-pinctrl.txt
index 0211c6d8a522..92fae82f35f2 100644
--- a/Documentation/devicetree/bindings/pinctrl/qcom,apq8064-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/qcom,apq8064-pinctrl.txt
@@ -62,7 +62,7 @@ Example:
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
- interrupts = <0 32 0x4>;
+ interrupts = <0 16 0x4>;
pinctrl-names = "default";
pinctrl-0 = <&gsbi5_uart_default>;
diff --git a/Documentation/devicetree/bindings/regulator/tps65090.txt b/Documentation/devicetree/bindings/regulator/tps65090.txt
index 340980239ea9..ca69f5e3040c 100644
--- a/Documentation/devicetree/bindings/regulator/tps65090.txt
+++ b/Documentation/devicetree/bindings/regulator/tps65090.txt
@@ -45,8 +45,8 @@ Example:
infet5-supply = <&some_reg>;
infet6-supply = <&some_reg>;
infet7-supply = <&some_reg>;
- vsys_l1-supply = <&some_reg>;
- vsys_l2-supply = <&some_reg>;
+ vsys-l1-supply = <&some_reg>;
+ vsys-l2-supply = <&some_reg>;
regulators {
dcdc1 {
diff --git a/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt b/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt
index 46f344965313..4eb7997674a0 100644
--- a/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt
+++ b/Documentation/devicetree/bindings/sound/adi,axi-spdif-tx.txt
@@ -1,7 +1,7 @@
ADI AXI-SPDIF controller
Required properties:
- - compatible : Must be "adi,axi-spdif-1.00.a"
+ - compatible : Must be "adi,axi-spdif-tx-1.00.a"
- reg : Must contain SPDIF core's registers location and length
- clocks : Pairs of phandle and specifier referencing the controller's clocks.
The controller expects two clocks, the clock used for the AXI interface and
diff --git a/Documentation/devicetree/bindings/sound/rockchip-i2s.txt b/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
index 6c55fcfe5e1d..9b82c20b306b 100644
--- a/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
+++ b/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
@@ -31,7 +31,7 @@ i2s@ff890000 {
#address-cells = <1>;
#size-cells = <0>;
dmas = <&pdma1 0>, <&pdma1 1>;
- dma-names = "rx", "tx";
+ dma-names = "tx", "rx";
clock-names = "i2s_hclk", "i2s_clk";
clocks = <&cru HCLK_I2S0>, <&cru SCLK_I2S0>;
};
diff --git a/Documentation/devicetree/bindings/spi/spi-rockchip.txt b/Documentation/devicetree/bindings/spi/spi-rockchip.txt
index 7bab35575817..467dec441c62 100644
--- a/Documentation/devicetree/bindings/spi/spi-rockchip.txt
+++ b/Documentation/devicetree/bindings/spi/spi-rockchip.txt
@@ -16,11 +16,15 @@ Required Properties:
- clocks: Must contain an entry for each entry in clock-names.
- clock-names: Shall be "spiclk" for the transfer-clock, and "apb_pclk" for
the peripheral clock.
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+
+Optional Properties:
+
- dmas: DMA specifiers for tx and rx dma. See the DMA client binding,
Documentation/devicetree/bindings/dma/dma.txt
- dma-names: DMA request names should include "tx" and "rx" if present.
-- #address-cells: should be 1.
-- #size-cells: should be 0.
+
Example:
diff --git a/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt b/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt
index 578a1fca366e..443bcb6134d5 100644
--- a/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt
+++ b/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt
@@ -56,6 +56,9 @@ Required properties:
- fsl,data-width : should be <18> or <24>
- port: A port node with endpoint definitions as defined in
Documentation/devicetree/bindings/media/video-interfaces.txt.
+ On i.MX5, the internal two-input-multiplexer is used.
+ Due to hardware limitations, only one port (port@[0,1])
+ can be used for each channel (lvds-channel@[0,1], respectively)
On i.MX6, there should be four ports (port@[0-3]) that correspond
to the four LVDS multiplexer inputs.
@@ -78,6 +81,8 @@ ldb: ldb@53fa8008 {
"di0", "di1";
lvds-channel@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
reg = <0>;
fsl,data-mapping = "spwg";
fsl,data-width = <24>;
@@ -86,7 +91,9 @@ ldb: ldb@53fa8008 {
/* ... */
};
- port {
+ port@0 {
+ reg = <0>;
+
lvds0_in: endpoint {
remote-endpoint = <&ipu_di0_lvds0>;
};
@@ -94,6 +101,8 @@ ldb: ldb@53fa8008 {
};
lvds-channel@1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
reg = <1>;
fsl,data-mapping = "spwg";
fsl,data-width = <24>;
@@ -102,7 +111,9 @@ ldb: ldb@53fa8008 {
/* ... */
};
- port {
+ port@1 {
+ reg = <1>;
+
lvds1_in: endpoint {
remote-endpoint = <&ipu_di1_lvds1>;
};
diff --git a/Documentation/devicetree/bindings/usb/mxs-phy.txt b/Documentation/devicetree/bindings/usb/mxs-phy.txt
index cef181a9d8bd..96681c93b86d 100644
--- a/Documentation/devicetree/bindings/usb/mxs-phy.txt
+++ b/Documentation/devicetree/bindings/usb/mxs-phy.txt
@@ -5,6 +5,7 @@ Required properties:
* "fsl,imx23-usbphy" for imx23 and imx28
* "fsl,imx6q-usbphy" for imx6dq and imx6dl
* "fsl,imx6sl-usbphy" for imx6sl
+ * "fsl,imx6sx-usbphy" for imx6sx
"fsl,imx23-usbphy" is still a fallback for other strings
- reg: Should contain registers location and length
- interrupts: Should contain phy interrupt
diff --git a/Documentation/devicetree/bindings/video/analog-tv-connector.txt b/Documentation/devicetree/bindings/video/analog-tv-connector.txt
index 0218fcdc1299..0c0970c210ab 100644
--- a/Documentation/devicetree/bindings/video/analog-tv-connector.txt
+++ b/Documentation/devicetree/bindings/video/analog-tv-connector.txt
@@ -2,7 +2,7 @@ Analog TV Connector
===================
Required properties:
-- compatible: "composite-connector" or "svideo-connector"
+- compatible: "composite-video-connector" or "svideo-connector"
Optional properties:
- label: a symbolic name for the connector
@@ -14,7 +14,7 @@ Example
-------
tv: connector {
- compatible = "composite-connector";
+ compatible = "composite-video-connector";
label = "tv";
port {
diff --git a/Documentation/devicetree/of_selftest.txt b/Documentation/devicetree/of_selftest.txt
new file mode 100644
index 000000000000..3a2f54d07fc5
--- /dev/null
+++ b/Documentation/devicetree/of_selftest.txt
@@ -0,0 +1,211 @@
+Open Firmware Device Tree Selftest
+----------------------------------
+
+Author: Gaurav Minocha <gaurav.minocha.os@gmail.com>
+
+1. Introduction
+
+This document explains how the test data required for executing OF selftest
+is attached to the live tree dynamically, independent of the machine's
+architecture.
+
+It is recommended to read the following documents before moving ahead.
+
+[1] Documentation/devicetree/usage-model.txt
+[2] http://www.devicetree.org/Device_Tree_Usage
+
+OF Selftest has been designed to test the interface (include/linux/of.h)
+provided to device driver developers to fetch the device information..etc.
+from the unflattened device tree data structure. This interface is used by
+most of the device drivers in various use cases.
+
+
+2. Test-data
+
+The Device Tree Source file (drivers/of/testcase-data/testcases.dts) contains
+the test data required for executing the unit tests automated in
+drivers/of/selftests.c. Currently, following Device Tree Source Include files
+(.dtsi) are included in testcase.dts:
+
+drivers/of/testcase-data/tests-interrupts.dtsi
+drivers/of/testcase-data/tests-platform.dtsi
+drivers/of/testcase-data/tests-phandle.dtsi
+drivers/of/testcase-data/tests-match.dtsi
+
+When the kernel is build with OF_SELFTEST enabled, then the following make rule
+
+$(obj)/%.dtb: $(src)/%.dts FORCE
+ $(call if_changed_dep, dtc)
+
+is used to compile the DT source file (testcase.dts) into a binary blob
+(testcase.dtb), also referred as flattened DT.
+
+After that, using the following rule the binary blob above is wrapped as an
+assembly file (testcase.dtb.S).
+
+$(obj)/%.dtb.S: $(obj)/%.dtb
+ $(call cmd, dt_S_dtb)
+
+The assembly file is compiled into an object file (testcase.dtb.o), and is
+linked into the kernel image.
+
+
+2.1. Adding the test data
+
+Un-flattened device tree structure:
+
+Un-flattened device tree consists of connected device_node(s) in form of a tree
+structure described below.
+
+// following struct members are used to construct the tree
+struct device_node {
+ ...
+ struct device_node *parent;
+ struct device_node *child;
+ struct device_node *sibling;
+ struct device_node *allnext; /* next in list of all nodes */
+ ...
+ };
+
+Figure 1, describes a generic structure of machine’s un-flattened device tree
+considering only child and sibling pointers. There exists another pointer,
+*parent, that is used to traverse the tree in the reverse direction. So, at
+a particular level the child node and all the sibling nodes will have a parent
+pointer pointing to a common node (e.g. child1, sibling2, sibling3, sibling4’s
+parent points to root node)
+
+root (‘/’)
+ |
+child1 -> sibling2 -> sibling3 -> sibling4 -> null
+ | | | |
+ | | | null
+ | | |
+ | | child31 -> sibling32 -> null
+ | | | |
+ | | null null
+ | |
+ | child21 -> sibling22 -> sibling23 -> null
+ | | | |
+ | null null null
+ |
+child11 -> sibling12 -> sibling13 -> sibling14 -> null
+ | | | |
+ | | | null
+ | | |
+ null null child131 -> null
+ |
+ null
+
+Figure 1: Generic structure of un-flattened device tree
+
+
+*allnext: it is used to link all the nodes of DT into a list. So, for the
+ above tree the list would be as follows:
+
+root->child1->child11->sibling12->sibling13->child131->sibling14->sibling2->
+child21->sibling22->sibling23->sibling3->child31->sibling32->sibling4->null
+
+Before executing OF selftest, it is required to attach the test data to
+machine's device tree (if present). So, when selftest_data_add() is called,
+at first it reads the flattened device tree data linked into the kernel image
+via the following kernel symbols:
+
+__dtb_testcases_begin - address marking the start of test data blob
+__dtb_testcases_end - address marking the end of test data blob
+
+Secondly, it calls of_fdt_unflatten_device_tree() to unflatten the flattened
+blob. And finally, if the machine’s device tree (i.e live tree) is present,
+then it attaches the unflattened test data tree to the live tree, else it
+attaches itself as a live device tree.
+
+attach_node_and_children() uses of_attach_node() to attach the nodes into the
+live tree as explained below. To explain the same, the test data tree described
+ in Figure 2 is attached to the live tree described in Figure 1.
+
+root (‘/’)
+ |
+ testcase-data
+ |
+ test-child0 -> test-sibling1 -> test-sibling2 -> test-sibling3 -> null
+ | | | |
+ test-child01 null null null
+
+
+allnext list:
+
+root->testcase-data->test-child0->test-child01->test-sibling1->test-sibling2
+->test-sibling3->null
+
+Figure 2: Example test data tree to be attached to live tree.
+
+According to the scenario above, the live tree is already present so it isn’t
+required to attach the root(‘/’) node. All other nodes are attached by calling
+of_attach_node() on each node.
+
+In the function of_attach_node(), the new node is attached as the child of the
+given parent in live tree. But, if parent already has a child then the new node
+replaces the current child and turns it into its sibling. So, when the testcase
+data node is attached to the live tree above (Figure 1), the final structure is
+ as shown in Figure 3.
+
+root (‘/’)
+ |
+testcase-data -> child1 -> sibling2 -> sibling3 -> sibling4 -> null
+ | | | | |
+ (...) | | | null
+ | | child31 -> sibling32 -> null
+ | | | |
+ | | null null
+ | |
+ | child21 -> sibling22 -> sibling23 -> null
+ | | | |
+ | null null null
+ |
+ child11 -> sibling12 -> sibling13 -> sibling14 -> null
+ | | | |
+ null null | null
+ |
+ child131 -> null
+ |
+ null
+-----------------------------------------------------------------------
+
+root (‘/’)
+ |
+testcase-data -> child1 -> sibling2 -> sibling3 -> sibling4 -> null
+ | | | | |
+ | (...) (...) (...) null
+ |
+test-sibling3 -> test-sibling2 -> test-sibling1 -> test-child0 -> null
+ | | | |
+ null null null test-child01
+
+
+Figure 3: Live device tree structure after attaching the testcase-data.
+
+
+Astute readers would have noticed that test-child0 node becomes the last
+sibling compared to the earlier structure (Figure 2). After attaching first
+test-child0 the test-sibling1 is attached that pushes the child node
+(i.e. test-child0) to become a sibling and makes itself a child node,
+ as mentioned above.
+
+If a duplicate node is found (i.e. if a node with same full_name property is
+already present in the live tree), then the node isn’t attached rather its
+properties are updated to the live tree’s node by calling the function
+update_node_properties().
+
+
+2.2. Removing the test data
+
+Once the test case execution is complete, selftest_data_remove is called in
+order to remove the device nodes attached initially (first the leaf nodes are
+detached and then moving up the parent nodes are removed, and eventually the
+whole tree). selftest_data_remove() calls detach_node_and_children() that uses
+of_detach_node() to detach the nodes from the live device tree.
+
+To detach a node, of_detach_node() first updates all_next linked list, by
+attaching the previous node’s allnext to current node’s allnext pointer. And
+then, it either updates the child pointer of given node’s parent to its
+sibling or attaches the previous sibling to the given node’s sibling, as
+appropriate. That is it :)