diff options
Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/00-INDEX | 10 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/ce4100-i2c.txt | 93 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/rtc-cmos.txt | 28 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/x86/ce4100.txt | 38 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/x86/interrupt.txt | 26 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/x86/timer.txt | 6 | ||||
| -rw-r--r-- | Documentation/devicetree/booting-without-of.txt | 20 |
7 files changed, 221 insertions, 0 deletions
diff --git a/Documentation/devicetree/00-INDEX b/Documentation/devicetree/00-INDEX new file mode 100644 index 000000000000..b78f691fd847 --- /dev/null +++ b/Documentation/devicetree/00-INDEX @@ -0,0 +1,10 @@ +Documentation for device trees, a data structure by which bootloaders pass +hardware layout to Linux in a device-independent manner, simplifying hardware +probing. This subsystem is maintained by Grant Likely +<grant.likely@secretlab.ca> and has a mailing list at +https://lists.ozlabs.org/listinfo/devicetree-discuss + +00-INDEX + - this file +booting-without-of.txt + - Booting Linux without Open Firmware, describes history and format of device trees. diff --git a/Documentation/devicetree/bindings/i2c/ce4100-i2c.txt b/Documentation/devicetree/bindings/i2c/ce4100-i2c.txt new file mode 100644 index 000000000000..569b16248514 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/ce4100-i2c.txt @@ -0,0 +1,93 @@ +CE4100 I2C +---------- + +CE4100 has one PCI device which is described as the I2C-Controller. This +PCI device has three PCI-bars, each bar contains a complete I2C +controller. So we have a total of three independent I2C-Controllers +which share only an interrupt line. +The driver is probed via the PCI-ID and is gathering the information of +attached devices from the devices tree. +Grant Likely recommended to use the ranges property to map the PCI-Bar +number to its physical address and to use this to find the child nodes +of the specific I2C controller. This were his exact words: + + Here's where the magic happens. Each entry in + ranges describes how the parent pci address space + (middle group of 3) is translated to the local + address space (first group of 2) and the size of + each range (last cell). In this particular case, + the first cell of the local address is chosen to be + 1:1 mapped to the BARs, and the second is the + offset from be base of the BAR (which would be + non-zero if you had 2 or more devices mapped off + the same BAR) + + ranges allows the address mapping to be described + in a way that the OS can interpret without + requiring custom device driver code. + +This is an example which is used on FalconFalls: +------------------------------------------------ + i2c-controller@b,2 { + #address-cells = <2>; + #size-cells = <1>; + compatible = "pci8086,2e68.2", + "pci8086,2e68", + "pciclass,ff0000", + "pciclass,ff00"; + + reg = <0x15a00 0x0 0x0 0x0 0x0>; + interrupts = <16 1>; + + /* as described by Grant, the first number in the group of + * three is the bar number followed by the 64bit bar address + * followed by size of the mapping. The bar address + * requires also a valid translation in parents ranges + * property. + */ + ranges = <0 0 0x02000000 0 0xdffe0500 0x100 + 1 0 0x02000000 0 0xdffe0600 0x100 + 2 0 0x02000000 0 0xdffe0700 0x100>; + + i2c@0 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "intel,ce4100-i2c-controller"; + + /* The first number in the reg property is the + * number of the bar + */ + reg = <0 0 0x100>; + + /* This I2C controller has no devices */ + }; + + i2c@1 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "intel,ce4100-i2c-controller"; + reg = <1 0 0x100>; + + /* This I2C controller has one gpio controller */ + gpio@26 { + #gpio-cells = <2>; + compatible = "ti,pcf8575"; + reg = <0x26>; + gpio-controller; + }; + }; + + i2c@2 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "intel,ce4100-i2c-controller"; + reg = <2 0 0x100>; + + gpio@26 { + #gpio-cells = <2>; + compatible = "ti,pcf8575"; + reg = <0x26>; + gpio-controller; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/rtc/rtc-cmos.txt b/Documentation/devicetree/bindings/rtc/rtc-cmos.txt new file mode 100644 index 000000000000..7382989b3052 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/rtc-cmos.txt @@ -0,0 +1,28 @@ + Motorola mc146818 compatible RTC +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Required properties: + - compatible : "motorola,mc146818" + - reg : should contain registers location and length. + +Optional properties: + - interrupts : should contain interrupt. + - interrupt-parent : interrupt source phandle. + - ctrl-reg : Contains the initial value of the control register also + called "Register B". + - freq-reg : Contains the initial value of the frequency register also + called "Regsiter A". + +"Register A" and "B" are usually initialized by the firmware (BIOS for +instance). If this is not done, it can be performed by the driver. + +ISA Example: + + rtc@70 { + compatible = "motorola,mc146818"; + interrupts = <8 3>; + interrupt-parent = <&ioapic1>; + ctrl-reg = <2>; + freq-reg = <0x26>; + reg = <1 0x70 2>; + }; diff --git a/Documentation/devicetree/bindings/x86/ce4100.txt b/Documentation/devicetree/bindings/x86/ce4100.txt new file mode 100644 index 000000000000..b49ae593a60b --- /dev/null +++ b/Documentation/devicetree/bindings/x86/ce4100.txt @@ -0,0 +1,38 @@ +CE4100 Device Tree Bindings +--------------------------- + +The CE4100 SoC uses for in core peripherals the following compatible +format: <vendor>,<chip>-<device>. +Many of the "generic" devices like HPET or IO APIC have the ce4100 +name in their compatible property because they first appeared in this +SoC. + +The CPU node +------------ + cpu@0 { + device_type = "cpu"; + compatible = "intel,ce4100"; + reg = <0>; + lapic = <&lapic0>; + }; + +The reg property describes the CPU number. The lapic property points to +the local APIC timer. + +The SoC node +------------ + +This node describes the in-core peripherals. Required property: + compatible = "intel,ce4100-cp"; + +The PCI node +------------ +This node describes the PCI bus on the SoC. Its property should be + compatible = "intel,ce4100-pci", "pci"; + +If the OS is using the IO-APIC for interrupt routing then the reported +interrupt numbers for devices is no longer true. In order to obtain the +correct interrupt number, the child node which represents the device has +to contain the interrupt property. Besides the interrupt property it has +to contain at least the reg property containing the PCI bus address and +compatible property according to "PCI Bus Binding Revision 2.1". diff --git a/Documentation/devicetree/bindings/x86/interrupt.txt b/Documentation/devicetree/bindings/x86/interrupt.txt new file mode 100644 index 000000000000..7d19f494f19a --- /dev/null +++ b/Documentation/devicetree/bindings/x86/interrupt.txt @@ -0,0 +1,26 @@ +Interrupt chips +--------------- + +* Intel I/O Advanced Programmable Interrupt Controller (IO APIC) + + Required properties: + -------------------- + compatible = "intel,ce4100-ioapic"; + #interrupt-cells = <2>; + + Device's interrupt property: + + interrupts = <P S>; + + The first number (P) represents the interrupt pin which is wired to the + IO APIC. The second number (S) represents the sense of interrupt which + should be configured and can be one of: + 0 - Edge Rising + 1 - Level Low + 2 - Level High + 3 - Edge Falling + +* Local APIC + Required property: + + compatible = "intel,ce4100-lapic"; diff --git a/Documentation/devicetree/bindings/x86/timer.txt b/Documentation/devicetree/bindings/x86/timer.txt new file mode 100644 index 000000000000..c688af58e3bd --- /dev/null +++ b/Documentation/devicetree/bindings/x86/timer.txt @@ -0,0 +1,6 @@ +Timers +------ + +* High Precision Event Timer (HPET) + Required property: + compatible = "intel,ce4100-hpet"; diff --git a/Documentation/devicetree/booting-without-of.txt b/Documentation/devicetree/booting-without-of.txt index 28b1c9d3d351..55fd2623445b 100644 --- a/Documentation/devicetree/booting-without-of.txt +++ b/Documentation/devicetree/booting-without-of.txt @@ -13,6 +13,7 @@ Table of Contents I - Introduction 1) Entry point for arch/powerpc + 2) Entry point for arch/x86 II - The DT block format 1) Header @@ -225,6 +226,25 @@ it with special cases. cannot support both configurations with Book E and configurations with classic Powerpc architectures. +2) Entry point for arch/x86 +------------------------------- + + There is one single 32bit entry point to the kernel at code32_start, + the decompressor (the real mode entry point goes to the same 32bit + entry point once it switched into protected mode). That entry point + supports one calling convention which is documented in + Documentation/x86/boot.txt + The physical pointer to the device-tree block (defined in chapter II) + is passed via setup_data which requires at least boot protocol 2.09. + The type filed is defined as + + #define SETUP_DTB 2 + + This device-tree is used as an extension to the "boot page". As such it + does not parse / consider data which is already covered by the boot + page. This includes memory size, reserved ranges, command line arguments + or initrd address. It simply holds information which can not be retrieved + otherwise like interrupt routing or a list of devices behind an I2C bus. II - The DT block format ======================== |