Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt

   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                         "microchip,sam9x60-ebi"
  19
  20 - reg:                  Contains offset/length value for EBI memory mapping.
  21                         This property might contain several entries if the EBI
  22                         memory range is not contiguous
  23
  24 - #address-cells:       Must be 2.
  25                         The first cell encodes the CS.
  26                         The second cell encode the offset into the CS memory
  27                         range.
  28
  29 - #size-cells:          Must be set to 1.
  30
  31 - ranges:               Encodes CS to memory region association.
  32
  33 - clocks:               Clock feeding the EBI controller.
  34                         See clock-bindings.txt
  35
  36 Children device nodes are representing device connected to the EBI bus.
  37
  38 Required device node properties:
  39
  40 - reg:                  Contains the chip-select id, the offset and the length
  41                         of the memory region requested by the device.
  42
  43 EBI bus configuration will be defined directly in the device subnode.
  44
  45 Optional EBI/SMC properties:
  46
  47 - atmel,smc-bus-width:          width of the asynchronous device's data bus
  48                                 8, 16 or 32.
  49                                 Default to 8 when undefined.
  50
  51 - atmel,smc-byte-access-type    "write" or "select" (see Atmel datasheet).
  52                                 Default to "select" when undefined.
  53
  54 - atmel,smc-read-mode           "nrd" or "ncs".
  55                                 Default to "ncs" when undefined.
  56
  57 - atmel,smc-write-mode          "nwe" or "ncs".
  58                                 Default to "ncs" when undefined.
  59
  60 - atmel,smc-exnw-mode           "disabled", "frozen" or "ready".
  61                                 Default to "disabled" when undefined.
  62
  63 - atmel,smc-page-mode           enable page mode if present. The provided value
  64                                 defines the page size (supported values: 4, 8,
  65                                 16 and 32).
  66
  67 - atmel,smc-tdf-mode:           "normal" or "optimized". When set to
  68                                 "optimized" the data float time is optimized
  69                                 depending on the next device being accessed
  70                                 (next device setup time is subtracted to the
  71                                 current device data float time).
  72                                 Default to "normal" when undefined.
  73
  74 If at least one atmel,smc- property is defined the following SMC timing
  75 properties become mandatory. In the other hand, if none of the atmel,smc-
  76 properties are specified, we assume that the EBI bus configuration will be
  77 handled by the sub-device driver, and none of those properties should be
  78 defined.
  79
  80 All the timings are expressed in nanoseconds (see Atmel datasheet for a full
  81 description).
  82
  83 - atmel,smc-ncs-rd-setup-ns
  84 - atmel,smc-nrd-setup-ns
  85 - atmel,smc-ncs-wr-setup-ns
  86 - atmel,smc-nwe-setup-ns
  87 - atmel,smc-ncs-rd-pulse-ns
  88 - atmel,smc-nrd-pulse-ns
  89 - atmel,smc-ncs-wr-pulse-ns
  90 - atmel,smc-nwe-pulse-ns
  91 - atmel,smc-nwe-cycle-ns
  92 - atmel,smc-nrd-cycle-ns
  93 - atmel,smc-tdf-ns
  94
  95 Example:
  96
  97         ebi: ebi@10000000 {
  98                 compatible = "atmel,sama5d3-ebi";
  99                 #address-cells = <2>;
 100                 #size-cells = <1>;
 101                 atmel,smc = <&hsmc>;
 102                 atmel,matrix = <&matrix>;
 103                 reg = <0x10000000 0x10000000
 104                        0x40000000 0x30000000>;
 105                 ranges = <0x0 0x0 0x10000000 0x10000000
 106                           0x1 0x0 0x40000000 0x10000000
 107                           0x2 0x0 0x50000000 0x10000000
 108                           0x3 0x0 0x60000000 0x10000000>;
 109                 clocks = <&mck>;
 110
 111                 pinctrl-names = "default";
 112                 pinctrl-0 = <&pinctrl_ebi_addr>;
 113
 114                 nor: flash@0,0 {
 115                         compatible = "cfi-flash";
 116                         #address-cells = <1>;
 117                         #size-cells = <1>;
 118                         reg = <0x0 0x0 0x1000000>;
 119                         bank-width = <2>;
 120
 121                         atmel,smc-read-mode = "nrd";
 122                         atmel,smc-write-mode = "nwe";
 123                         atmel,smc-bus-width = <16>;
 124                         atmel,smc-ncs-rd-setup-ns = <0>;
 125                         atmel,smc-ncs-wr-setup-ns = <0>;
 126                         atmel,smc-nwe-setup-ns = <8>;
 127                         atmel,smc-nrd-setup-ns = <16>;
 128                         atmel,smc-ncs-rd-pulse-ns = <84>;
 129                         atmel,smc-ncs-wr-pulse-ns = <84>;
 130                         atmel,smc-nrd-pulse-ns = <76>;
 131                         atmel,smc-nwe-pulse-ns = <76>;
 132                         atmel,smc-nrd-cycle-ns = <107>;
 133                         atmel,smc-nwe-cycle-ns = <84>;
 134                         atmel,smc-tdf-ns = <16>;
 135                 };
 136         };
 137