linux/Documentation/devicetree/bindings/powerpc/fsl/mpc5200.txt
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   1MPC5200 Device Tree Bindings
   2----------------------------
   3
   4(c) 2006-2009 Secret Lab Technologies Ltd
   5Grant Likely <grant.likely@secretlab.ca>
   6
   7Naming conventions
   8------------------
   9For mpc5200 on-chip devices, the format for each compatible value is
  10<chip>-<device>[-<mode>].  The OS should be able to match a device driver
  11to the device based solely on the compatible value.  If two drivers
  12match on the compatible list; the 'most compatible' driver should be
  13selected.
  14
  15The split between the MPC5200 and the MPC5200B leaves a bit of a
  16conundrum.  How should the compatible property be set up to provide
  17maximum compatibility information; but still accurately describe the
  18chip?  For the MPC5200; the answer is easy.  Most of the SoC devices
  19originally appeared on the MPC5200.  Since they didn't exist anywhere
  20else; the 5200 compatible properties will contain only one item;
  21"fsl,mpc5200-<device>".
  22
  23The 5200B is almost the same as the 5200, but not quite.  It fixes
  24silicon bugs and it adds a small number of enhancements.  Most of the
  25devices either provide exactly the same interface as on the 5200.  A few
  26devices have extra functions but still have a backwards compatible mode.
  27To express this information as completely as possible, 5200B device trees
  28should have two items in the compatible list:
  29        compatible = "fsl,mpc5200b-<device>","fsl,mpc5200-<device>";
  30
  31It is *strongly* recommended that 5200B device trees follow this convention
  32(instead of only listing the base mpc5200 item).
  33
  34ie. ethernet on mpc5200: compatible = "fsl,mpc5200-fec";
  35    ethernet on mpc5200b: compatible = "fsl,mpc5200b-fec", "fsl,mpc5200-fec";
  36
  37Modal devices, like PSCs, also append the configured function to the
  38end of the compatible field.  ie. A PSC in i2s mode would specify
  39"fsl,mpc5200-psc-i2s", not "fsl,mpc5200-i2s".  This convention is chosen to
  40avoid naming conflicts with non-psc devices providing the same
  41function.  For example, "fsl,mpc5200-spi" and "fsl,mpc5200-psc-spi" describe
  42the mpc5200 simple spi device and a PSC spi mode respectively.
  43
  44At the time of writing, exact chip may be either 'fsl,mpc5200' or
  45'fsl,mpc5200b'.
  46
  47The soc node
  48------------
  49This node describes the on chip SOC peripherals.  Every mpc5200 based
  50board will have this node, and as such there is a common naming
  51convention for SOC devices.
  52
  53Required properties:
  54name                    description
  55----                    -----------
  56ranges                  Memory range of the internal memory mapped registers.
  57                        Should be <0 [baseaddr] 0xc000>
  58reg                     Should be <[baseaddr] 0x100>
  59compatible              mpc5200: "fsl,mpc5200-immr"
  60                        mpc5200b: "fsl,mpc5200b-immr"
  61system-frequency        'fsystem' frequency in Hz; XLB, IPB, USB and PCI
  62                        clocks are derived from the fsystem clock.
  63bus-frequency           IPB bus frequency in Hz.  Clock rate
  64                        used by most of the soc devices.
  65
  66soc child nodes
  67---------------
  68Any on chip SOC devices available to Linux must appear as soc5200 child nodes.
  69
  70Note: The tables below show the value for the mpc5200.  A mpc5200b device
  71tree should use the "fsl,mpc5200b-<device>","fsl,mpc5200-<device>" form.
  72
  73Required soc5200 child nodes:
  74name                            compatible              Description
  75----                            ----------              -----------
  76cdm@<addr>                      fsl,mpc5200-cdm         Clock Distribution
  77interrupt-controller@<addr>     fsl,mpc5200-pic         need an interrupt
  78                                                        controller to boot
  79bestcomm@<addr>                 fsl,mpc5200-bestcomm    Bestcomm DMA controller
  80
  81Recommended soc5200 child nodes; populate as needed for your board
  82name            compatible              Description
  83----            ----------              -----------
  84timer@<addr>    fsl,mpc5200-gpt          General purpose timers
  85gpio@<addr>     fsl,mpc5200-gpio         MPC5200 simple gpio controller
  86gpio@<addr>     fsl,mpc5200-gpio-wkup    MPC5200 wakeup gpio controller
  87rtc@<addr>      fsl,mpc5200-rtc          Real time clock
  88mscan@<addr>    fsl,mpc5200-mscan        CAN bus controller
  89pci@<addr>      fsl,mpc5200-pci          PCI bridge
  90serial@<addr>   fsl,mpc5200-psc-uart     PSC in serial mode
  91i2s@<addr>      fsl,mpc5200-psc-i2s      PSC in i2s mode
  92ac97@<addr>     fsl,mpc5200-psc-ac97     PSC in ac97 mode
  93spi@<addr>      fsl,mpc5200-psc-spi      PSC in spi mode
  94irda@<addr>     fsl,mpc5200-psc-irda     PSC in IrDA mode
  95spi@<addr>      fsl,mpc5200-spi          MPC5200 spi device
  96ethernet@<addr> fsl,mpc5200-fec          MPC5200 ethernet device
  97ata@<addr>      fsl,mpc5200-ata          IDE ATA interface
  98i2c@<addr>      fsl,mpc5200-i2c          I2C controller
  99usb@<addr>      fsl,mpc5200-ohci,ohci-be USB controller
 100xlb@<addr>      fsl,mpc5200-xlb          XLB arbitrator
 101
 102fsl,mpc5200-gpt nodes
 103---------------------
 104On the mpc5200 and 5200b, GPT0 has a watchdog timer function.  If the board
 105design supports the internal wdt, then the device node for GPT0 should
 106include the empty property 'fsl,has-wdt'.  Note that this does not activate
 107the watchdog.  The timer will function as a GPT if the timer api is used, and
 108it will function as watchdog if the watchdog device is used.  The watchdog
 109mode has priority over the gpt mode, i.e. if the watchdog is activated, any
 110gpt api call to this timer will fail with -EBUSY.
 111
 112If you add the property
 113        fsl,wdt-on-boot = <n>;
 114GPT0 will be marked as in-use watchdog, i.e. blocking every gpt access to it.
 115If n>0, the watchdog is started with a timeout of n seconds.  If n=0, the
 116configuration of the watchdog is not touched.  This is useful in two cases:
 117- just mark GPT0 as watchdog, blocking gpt accesses, and configure it later;
 118- do not touch a configuration assigned by the boot loader which supervises
 119  the boot process itself.
 120
 121The watchdog will respect the CONFIG_WATCHDOG_NOWAYOUT option.
 122
 123An mpc5200-gpt can be used as a single line GPIO controller.  To do so,
 124add the following properties to the gpt node:
 125        gpio-controller;
 126        #gpio-cells = <2>;
 127When referencing the GPIO line from another node, the first cell must always
 128be zero and the second cell represents the gpio flags and described in the
 129gpio device tree binding.
 130
 131An mpc5200-gpt can be used as a single line edge sensitive interrupt
 132controller.  To do so, add the following properties to the gpt node:
 133        interrupt-controller;
 134        #interrupt-cells = <1>;
 135When referencing the IRQ line from another node, the cell represents the
 136sense mode; 1 for edge rising, 2 for edge falling.
 137
 138fsl,mpc5200-psc nodes
 139---------------------
 140The PSCs should include a cell-index which is the index of the PSC in
 141hardware.  cell-index is used to determine which shared SoC registers to
 142use when setting up PSC clocking.  cell-index number starts at '0'.  ie:
 143        PSC1 has 'cell-index = <0>'
 144        PSC4 has 'cell-index = <3>'
 145
 146PSC in i2s mode:  The mpc5200 and mpc5200b PSCs are not compatible when in
 147i2s mode.  An 'mpc5200b-psc-i2s' node cannot include 'mpc5200-psc-i2s' in the
 148compatible field.
 149
 150
 151fsl,mpc5200-gpio and fsl,mpc5200-gpio-wkup nodes
 152------------------------------------------------
 153Each GPIO controller node should have the empty property gpio-controller and
 154#gpio-cells set to 2. First cell is the GPIO number which is interpreted
 155according to the bit numbers in the GPIO control registers. The second cell
 156is for flags which is currently unused.
 157
 158fsl,mpc5200-fec nodes
 159---------------------
 160The FEC node can specify one of the following properties to configure
 161the MII link:
 162- fsl,7-wire-mode - An empty property that specifies the link uses 7-wire
 163                    mode instead of MII
 164- current-speed   - Specifies that the MII should be configured for a fixed
 165                    speed.  This property should contain two cells.  The
 166                    first cell specifies the speed in Mbps and the second
 167                    should be '0' for half duplex and '1' for full duplex
 168- phy-handle      - Contains a phandle to an Ethernet PHY.
 169
 170Interrupt controller (fsl,mpc5200-pic) node
 171-------------------------------------------
 172The mpc5200 pic binding splits hardware IRQ numbers into two levels.  The
 173split reflects the layout of the PIC hardware itself, which groups
 174interrupts into one of three groups; CRIT, MAIN or PERP.  Also, the
 175Bestcomm dma engine has it's own set of interrupt sources which are
 176cascaded off of peripheral interrupt 0, which the driver interprets as a
 177fourth group, SDMA.
 178
 179The interrupts property for device nodes using the mpc5200 pic consists
 180of three cells; <L1 L2 level>
 181
 182    L1 := [CRIT=0, MAIN=1, PERP=2, SDMA=3]
 183    L2 := interrupt number; directly mapped from the value in the
 184          "ICTL PerStat, MainStat, CritStat Encoded Register"
 185    level := [LEVEL_HIGH=0, EDGE_RISING=1, EDGE_FALLING=2, LEVEL_LOW=3]
 186
 187For external IRQs, use the following interrupt property values (how to
 188specify external interrupts is a frequently asked question):
 189External interrupts:
 190        external irq0:  interrupts = <0 0 n>;
 191        external irq1:  interrupts = <1 1 n>;
 192        external irq2:  interrupts = <1 2 n>;
 193        external irq3:  interrupts = <1 3 n>;
 194'n' is sense (0: level high, 1: edge rising, 2: edge falling 3: level low)
 195
 196fsl,mpc5200-mscan nodes
 197-----------------------
 198See file can.txt in this directory.
 199