1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/bus/intel,ixp4xx-expansion-bus-controller.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Intel IXP4xx Expansion Bus Controller
8
9 description: |
10 The IXP4xx expansion bus controller handles access to devices on the
11 memory-mapped expansion bus on the Intel IXP4xx family of system on chips,
12 including IXP42x, IXP43x, IXP45x and IXP46x.
13
14 maintainers:
15 - Linus Walleij <linus.walleij@linaro.org>
16
17 properties:
18 $nodename:
19 pattern: '^bus@[0-9a-f]+$'
20
21 compatible:
22 items:
23 - enum:
24 - intel,ixp42x-expansion-bus-controller
25 - intel,ixp43x-expansion-bus-controller
26 - intel,ixp45x-expansion-bus-controller
27 - intel,ixp46x-expansion-bus-controller
28 - const: syscon
29
30 reg:
31 description: Control registers for the expansion bus, these are not
32 inside the memory range handled by the expansion bus.
33 maxItems: 1
34
35 native-endian:
36 $ref: /schemas/types.yaml#/definitions/flag
37 description: The IXP4xx has a peculiar MMIO access scheme, as it changes
38 the access pattern for words (swizzling) on the bus depending on whether
39 the SoC is running in big-endian or little-endian mode. Thus the
40 registers must always be accessed using native endianness.
41
42 "#address-cells":
43 description: |
44 The first cell is the chip select number.
45 The second cell is the address offset within the bank.
46 const: 2
47
48 "#size-cells":
49 const: 1
50
51 ranges: true
52 dma-ranges: true
53
54 patternProperties:
55 "^.*@[0-7],[0-9a-f]+$":
56 description: Devices attached to chip selects are represented as
57 subnodes.
58 type: object
59
60 properties:
61 intel,ixp4xx-eb-t1:
62 description: Address timing, extend address phase with n cycles.
63 $ref: /schemas/types.yaml#/definitions/uint32
64 maximum: 3
65
66 intel,ixp4xx-eb-t2:
67 description: Setup chip select timing, extend setup phase with n cycles.
68 $ref: /schemas/types.yaml#/definitions/uint32
69 maximum: 3
70
71 intel,ixp4xx-eb-t3:
72 description: Strobe timing, extend strobe phase with n cycles.
73 $ref: /schemas/types.yaml#/definitions/uint32
74 maximum: 15
75
76 intel,ixp4xx-eb-t4:
77 description: Hold timing, extend hold phase with n cycles.
78 $ref: /schemas/types.yaml#/definitions/uint32
79 maximum: 3
80
81 intel,ixp4xx-eb-t5:
82 description: Recovery timing, extend recovery phase with n cycles.
83 $ref: /schemas/types.yaml#/definitions/uint32
84 maximum: 15
85
86 intel,ixp4xx-eb-cycle-type:
87 description: The type of cycles to use on the expansion bus for this
88 chip select. 0 = Intel cycles, 1 = Motorola cycles, 2 = HPI cycles.
89 $ref: /schemas/types.yaml#/definitions/uint32
90 enum: [0, 1, 2]
91
92 intel,ixp4xx-eb-byte-access-on-halfword:
93 description: Allow byte read access on half word devices.
94 $ref: /schemas/types.yaml#/definitions/uint32
95 enum: [0, 1]
96
97 intel,ixp4xx-eb-hpi-hrdy-pol-high:
98 description: Set HPI HRDY polarity to active high when using HPI.
99 $ref: /schemas/types.yaml#/definitions/uint32
100 enum: [0, 1]
101
102 intel,ixp4xx-eb-mux-address-and-data:
103 description: Multiplex address and data on the data bus.
104 $ref: /schemas/types.yaml#/definitions/uint32
105 enum: [0, 1]
106
107 intel,ixp4xx-eb-ahb-split-transfers:
108 description: Enable AHB split transfers.
109 $ref: /schemas/types.yaml#/definitions/uint32
110 enum: [0, 1]
111
112 intel,ixp4xx-eb-write-enable:
113 description: Enable write cycles.
114 $ref: /schemas/types.yaml#/definitions/uint32
115 enum: [0, 1]
116
117 intel,ixp4xx-eb-byte-access:
118 description: Expansion bus uses only 8 bits. The default is to use
119 16 bits.
120 $ref: /schemas/types.yaml#/definitions/uint32
121 enum: [0, 1]
122
123 required:
124 - compatible
125 - reg
126 - native-endian
127 - "#address-cells"
128 - "#size-cells"
129 - ranges
130 - dma-ranges
131
132 additionalProperties: false
133
134 examples:
135 - |
136 #include <dt-bindings/interrupt-controller/irq.h>
137 bus@50000000 {
138 compatible = "intel,ixp42x-expansion-bus-controller", "syscon";
139 reg = <0xc4000000 0x28>;
140 native-endian;
141 #address-cells = <2>;
142 #size-cells = <1>;
143 ranges = <0 0x0 0x50000000 0x01000000>,
144 <1 0x0 0x51000000 0x01000000>;
145 dma-ranges = <0 0x0 0x50000000 0x01000000>,
146 <1 0x0 0x51000000 0x01000000>;
147 flash@0,0 {
148 compatible = "intel,ixp4xx-flash", "cfi-flash";
149 bank-width = <2>;
150 reg = <0 0x00000000 0x1000000>;
151 intel,ixp4xx-eb-t3 = <3>;
152 intel,ixp4xx-eb-cycle-type = <0>;
153 intel,ixp4xx-eb-byte-access-on-halfword = <1>;
154 intel,ixp4xx-eb-write-enable = <1>;
155 intel,ixp4xx-eb-byte-access = <0>;
156 };
157 serial@1,0 {
158 compatible = "exar,xr16l2551", "ns8250";
159 reg = <1 0x00000000 0x10>;
160 interrupt-parent = <&gpio0>;
161 interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
162 clock-frequency = <1843200>;
163 intel,ixp4xx-eb-t3 = <3>;
164 intel,ixp4xx-eb-cycle-type = <1>;
165 intel,ixp4xx-eb-write-enable = <1>;
166 intel,ixp4xx-eb-byte-access = <1>;
167 };
168 };
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