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