projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1fdab21d BB |
1 | * Device tree bindings for Atmel EBI |
| 2 | ||
| 3 | The External Bus Interface (EBI) controller is a bus where you can connect | |
| 4 | asynchronous (NAND, NOR, SRAM, ....) and synchronous memories (SDR/DDR SDRAMs). | |
| 5 | The EBI provides a glue-less interface to asynchronous memories through the SMC | |
| 6 | (Static Memory Controller). | |
| 7 | ||
| 8 | Required properties: | |
| 9 | ||
| 10 | - compatible: "atmel,at91sam9260-ebi" | |
| 11 | "atmel,at91sam9261-ebi" | |
| 12 | "atmel,at91sam9263-ebi0" | |
| 13 | "atmel,at91sam9263-ebi1" | |
| 14 | "atmel,at91sam9rl-ebi" | |
| 15 | "atmel,at91sam9g45-ebi" | |
| 16 | "atmel,at91sam9x5-ebi" | |
| 17 | "atmel,sama5d3-ebi" | |
| 18 | ||
| 19 | - reg: Contains offset/length value for EBI memory mapping. | |
| 20 | This property might contain several entries if the EBI | |
| 21 | memory range is not contiguous | |
| 22 | ||
| 23 | - #address-cells: Must be 2. | |
| 24 | The first cell encodes the CS. | |
| 25 | The second cell encode the offset into the CS memory | |
| 26 | range. | |
| 27 | ||
| 28 | - #size-cells: Must be set to 1. | |
| 29 | ||
| 30 | - ranges: Encodes CS to memory region association. | |
| 31 | ||
| 32 | - clocks: Clock feeding the EBI controller. | |
| 33 | See clock-bindings.txt | |
| 34 | ||
| 35 | Children device nodes are representing device connected to the EBI bus. | |
| 36 | ||
| 37 | Required device node properties: | |
| 38 | ||
| 39 | - reg: Contains the chip-select id, the offset and the length | |
| 40 | of the memory region requested by the device. | |
| 41 | ||
| 42 | EBI bus configuration will be defined directly in the device subnode. | |
| 43 | ||
| 44 | Optional EBI/SMC properties: | |
| 45 | ||
| 46 | - atmel,smc-bus-width: width of the asynchronous device's data bus | |
| 47 | 8, 16 or 32. | |
| 48 | Default to 8 when undefined. | |
| 49 | ||
| 50 | - atmel,smc-byte-access-type "write" or "select" (see Atmel datasheet). | |
| 51 | Default to "select" when undefined. | |
| 52 | ||
| 53 | - atmel,smc-read-mode "nrd" or "ncs". | |
| 54 | Default to "ncs" when undefined. | |
| 55 | ||
| 56 | - atmel,smc-write-mode "nwe" or "ncs". | |
| 57 | Default to "ncs" when undefined. | |
| 58 | ||
| 59 | - atmel,smc-exnw-mode "disabled", "frozen" or "ready". | |
| 60 | Default to "disabled" when undefined. | |
| 61 | ||
| 62 | - atmel,smc-page-mode enable page mode if present. The provided value | |
| 63 | defines the page size (supported values: 4, 8, | |
| 64 | 16 and 32). | |
| 65 | ||
| 66 | - atmel,smc-tdf-mode: "normal" or "optimized". When set to | |
| 67 | "optimized" the data float time is optimized | |
| 68 | depending on the next device being accessed | |
| 69 | (next device setup time is subtracted to the | |
| 70 | current device data float time). | |
| 71 | Default to "normal" when undefined. | |
| 72 | ||
| 73 | If at least one atmel,smc- property is defined the following SMC timing | |
| 74 | properties become mandatory. In the other hand, if none of the atmel,smc- | |
| 75 | properties are specified, we assume that the EBI bus configuration will be | |
| 76 | handled by the sub-device driver, and none of those properties should be | |
| 77 | defined. | |
| 78 | ||
| 79 | All the timings are expressed in nanoseconds (see Atmel datasheet for a full | |
| 80 | description). | |
| 81 | ||
| 82 | - atmel,smc-ncs-rd-setup-ns | |
| 83 | - atmel,smc-nrd-setup-ns | |
| 84 | - atmel,smc-ncs-wr-setup-ns | |
| 85 | - atmel,smc-nwe-setup-ns | |
| 86 | - atmel,smc-ncs-rd-pulse-ns | |
| 87 | - atmel,smc-nrd-pulse-ns | |
| 88 | - atmel,smc-ncs-wr-pulse-ns | |
| 89 | - atmel,smc-nwe-pulse-ns | |
| 90 | - atmel,smc-nwe-cycle-ns | |
| 91 | - atmel,smc-nrd-cycle-ns | |
| 92 | - atmel,smc-tdf-ns | |
| 93 | ||
| 94 | Example: | |
| 95 | ||
| 96 | ebi: ebi@10000000 { | |
| 97 | compatible = "atmel,sama5d3-ebi"; | |
| 98 | #address-cells = <2>; | |
| 99 | #size-cells = <1>; | |
| 100 | atmel,smc = <&hsmc>; | |
| 101 | atmel,matrix = <&matrix>; | |
| 102 | reg = <0x10000000 0x10000000 | |
| 103 | 0x40000000 0x30000000>; | |
| 104 | ranges = <0x0 0x0 0x10000000 0x10000000 | |
| 105 | 0x1 0x0 0x40000000 0x10000000 | |
| 106 | 0x2 0x0 0x50000000 0x10000000 | |
| 107 | 0x3 0x0 0x60000000 0x10000000>; | |
| 108 | clocks = <&mck>; | |
| 109 | ||
| 110 | pinctrl-names = "default"; | |
| 111 | pinctrl-0 = <&pinctrl_ebi_addr>; | |
| 112 | ||
| 113 | nor: flash@0,0 { | |
| 114 | compatible = "cfi-flash"; | |
| 115 | #address-cells = <1>; | |
| 116 | #size-cells = <1>; | |
| 117 | reg = <0x0 0x0 0x1000000>; | |
| 118 | bank-width = <2>; | |
| 119 | ||
| 120 | atmel,smc-read-mode = "nrd"; | |
| 121 | atmel,smc-write-mode = "nwe"; | |
| 122 | atmel,smc-bus-width = <16>; | |
| 123 | atmel,smc-ncs-rd-setup-ns = <0>; | |
| 124 | atmel,smc-ncs-wr-setup-ns = <0>; | |
| 125 | atmel,smc-nwe-setup-ns = <8>; | |
| 126 | atmel,smc-nrd-setup-ns = <16>; | |
| 127 | atmel,smc-ncs-rd-pulse-ns = <84>; | |
| 128 | atmel,smc-ncs-wr-pulse-ns = <84>; | |
| 129 | atmel,smc-nrd-pulse-ns = <76>; | |
| 130 | atmel,smc-nwe-pulse-ns = <76>; | |
| 131 | atmel,smc-nrd-cycle-ns = <107>; | |
| 132 | atmel,smc-nwe-cycle-ns = <84>; | |
| 133 | atmel,smc-tdf-ns = <16>; | |
| 134 | }; | |
| 135 | }; | |
| 136 |