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Diffstat (limited to 'Documentation/powerpc/dts-bindings/fsl/mpc5200.txt')
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diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt new file mode 100644 index 0000000..8447fd7 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt @@ -0,0 +1,180 @@ +MPC5200 Device Tree Bindings +---------------------------- + +(c) 2006-2009 Secret Lab Technologies Ltd +Grant Likely <grant.likely@secretlab.ca> + +Naming conventions +------------------ +For mpc5200 on-chip devices, the format for each compatible value is +<chip>-<device>[-<mode>]. The OS should be able to match a device driver +to the device based solely on the compatible value. If two drivers +match on the compatible list; the 'most compatible' driver should be +selected. + +The split between the MPC5200 and the MPC5200B leaves a bit of a +conundrum. How should the compatible property be set up to provide +maximum compatibility information; but still accurately describe the +chip? For the MPC5200; the answer is easy. Most of the SoC devices +originally appeared on the MPC5200. Since they didn't exist anywhere +else; the 5200 compatible properties will contain only one item; +"fsl,mpc5200-<device>". + +The 5200B is almost the same as the 5200, but not quite. It fixes +silicon bugs and it adds a small number of enhancements. Most of the +devices either provide exactly the same interface as on the 5200. A few +devices have extra functions but still have a backwards compatible mode. +To express this information as completely as possible, 5200B device trees +should have two items in the compatible list: + compatible = "fsl,mpc5200b-<device>","fsl,mpc5200-<device>"; + +It is *strongly* recommended that 5200B device trees follow this convention +(instead of only listing the base mpc5200 item). + +ie. ethernet on mpc5200: compatible = "fsl,mpc5200-fec"; + ethernet on mpc5200b: compatible = "fsl,mpc5200b-fec", "fsl,mpc5200-fec"; + +Modal devices, like PSCs, also append the configured function to the +end of the compatible field. ie. A PSC in i2s mode would specify +"fsl,mpc5200-psc-i2s", not "fsl,mpc5200-i2s". This convention is chosen to +avoid naming conflicts with non-psc devices providing the same +function. For example, "fsl,mpc5200-spi" and "fsl,mpc5200-psc-spi" describe +the mpc5200 simple spi device and a PSC spi mode respectively. + +At the time of writing, exact chip may be either 'fsl,mpc5200' or +'fsl,mpc5200b'. + +The soc node +------------ +This node describes the on chip SOC peripherals. Every mpc5200 based +board will have this node, and as such there is a common naming +convention for SOC devices. + +Required properties: +name description +---- ----------- +ranges Memory range of the internal memory mapped registers. + Should be <0 [baseaddr] 0xc000> +reg Should be <[baseaddr] 0x100> +compatible mpc5200: "fsl,mpc5200-immr" + mpc5200b: "fsl,mpc5200b-immr" +system-frequency 'fsystem' frequency in Hz; XLB, IPB, USB and PCI + clocks are derived from the fsystem clock. +bus-frequency IPB bus frequency in Hz. Clock rate + used by most of the soc devices. + +soc child nodes +--------------- +Any on chip SOC devices available to Linux must appear as soc5200 child nodes. + +Note: The tables below show the value for the mpc5200. A mpc5200b device +tree should use the "fsl,mpc5200b-<device>","fsl,mpc5200-<device>" form. + +Required soc5200 child nodes: +name compatible Description +---- ---------- ----------- +cdm@<addr> fsl,mpc5200-cdm Clock Distribution +interrupt-controller@<addr> fsl,mpc5200-pic need an interrupt + controller to boot +bestcomm@<addr> fsl,mpc5200-bestcomm Bestcomm DMA controller + +Recommended soc5200 child nodes; populate as needed for your board +name compatible Description +---- ---------- ----------- +timer@<addr> fsl,mpc5200-gpt General purpose timers +gpio@<addr> fsl,mpc5200-gpio MPC5200 simple gpio controller +gpio@<addr> fsl,mpc5200-gpio-wkup MPC5200 wakeup gpio controller +rtc@<addr> fsl,mpc5200-rtc Real time clock +mscan@<addr> fsl,mpc5200-mscan CAN bus controller +pci@<addr> fsl,mpc5200-pci PCI bridge +serial@<addr> fsl,mpc5200-psc-uart PSC in serial mode +i2s@<addr> fsl,mpc5200-psc-i2s PSC in i2s mode +ac97@<addr> fsl,mpc5200-psc-ac97 PSC in ac97 mode +spi@<addr> fsl,mpc5200-psc-spi PSC in spi mode +irda@<addr> fsl,mpc5200-psc-irda PSC in IrDA mode +spi@<addr> fsl,mpc5200-spi MPC5200 spi device +ethernet@<addr> fsl,mpc5200-fec MPC5200 ethernet device +ata@<addr> fsl,mpc5200-ata IDE ATA interface +i2c@<addr> fsl,mpc5200-i2c I2C controller +usb@<addr> fsl,mpc5200-ohci,ohci-be USB controller +xlb@<addr> fsl,mpc5200-xlb XLB arbitrator + +fsl,mpc5200-gpt nodes +--------------------- +On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board +design supports the internal wdt, then the device node for GPT0 should +include the empty property 'fsl,has-wdt'. + +An mpc5200-gpt can be used as a single line GPIO controller. To do so, +add the following properties to the gpt node: + gpio-controller; + #gpio-cells = <2>; +When referencing the GPIO line from another node, the first cell must always +be zero and the second cell represents the gpio flags and described in the +gpio device tree binding. + +An mpc5200-gpt can be used as a single line edge sensitive interrupt +controller. To do so, add the following properties to the gpt node: + interrupt-controller; + #interrupt-cells = <1>; +When referencing the IRQ line from another node, the cell represents the +sense mode; 1 for edge rising, 2 for edge falling. + +fsl,mpc5200-psc nodes +--------------------- +The PSCs should include a cell-index which is the index of the PSC in +hardware. cell-index is used to determine which shared SoC registers to +use when setting up PSC clocking. cell-index number starts at '0'. ie: + PSC1 has 'cell-index = <0>' + PSC4 has 'cell-index = <3>' + +PSC in i2s mode: The mpc5200 and mpc5200b PSCs are not compatible when in +i2s mode. An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the +compatible field. + + +fsl,mpc5200-gpio and fsl,mpc5200-gpio-wkup nodes +------------------------------------------------ +Each GPIO controller node should have the empty property gpio-controller and +#gpio-cells set to 2. First cell is the GPIO number which is interpreted +according to the bit numbers in the GPIO control registers. The second cell +is for flags which is currently unused. + +fsl,mpc5200-fec nodes +--------------------- +The FEC node can specify one of the following properties to configure +the MII link: +- fsl,7-wire-mode - An empty property that specifies the link uses 7-wire + mode instead of MII +- current-speed - Specifies that the MII should be configured for a fixed + speed. This property should contain two cells. The + first cell specifies the speed in Mbps and the second + should be '0' for half duplex and '1' for full duplex +- phy-handle - Contains a phandle to an Ethernet PHY. + +Interrupt controller (fsl,mpc5200-pic) node +------------------------------------------- +The mpc5200 pic binding splits hardware IRQ numbers into two levels. The +split reflects the layout of the PIC hardware itself, which groups +interrupts into one of three groups; CRIT, MAIN or PERP. Also, the +Bestcomm dma engine has it's own set of interrupt sources which are +cascaded off of peripheral interrupt 0, which the driver interprets as a +fourth group, SDMA. + +The interrupts property for device nodes using the mpc5200 pic consists +of three cells; <L1 L2 level> + + L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3] + L2 := interrupt number; directly mapped from the value in the + "ICTL PerStat, MainStat, CritStat Encoded Register" + level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3] + +For external IRQs, use the following interrupt property values (how to +specify external interrupts is a frequently asked question): +External interrupts: + external irq0: interrupts = <0 0 n>; + external irq1: interrupts = <1 1 n>; + external irq2: interrupts = <1 2 n>; + external irq3: interrupts = <1 3 n>; +'n' is sense (0: level high, 1: edge rising, 2: edge falling 3: level low) + |
