xref: /linux/Documentation/devicetree/bindings/serial/8250.yaml (revision 9f2c9170934eace462499ba0bfe042cc72900173) 
1# Copyright 2020 Lubomir Rintel <lkundrak@v3.sk>
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/serial/8250.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: UART (Universal Asynchronous Receiver/Transmitter)
8
9maintainers:
10  - devicetree@vger.kernel.org
11
12allOf:
13  - $ref: serial.yaml#
14  - if:
15      anyOf:
16        - required:
17            - aspeed,lpc-io-reg
18        - required:
19            - aspeed,lpc-interrupts
20        - required:
21            - aspeed,sirq-polarity-sense
22    then:
23      properties:
24        compatible:
25          const: aspeed,ast2500-vuart
26  - if:
27      properties:
28        compatible:
29          const: mrvl,mmp-uart
30    then:
31      properties:
32        reg-shift:
33          const: 2
34      required:
35        - reg-shift
36  - if:
37      not:
38        properties:
39          compatible:
40            items:
41              - enum:
42                  - ns8250
43                  - ns16450
44                  - ns16550
45                  - ns16550a
46    then:
47      anyOf:
48        - required: [ clock-frequency ]
49        - required: [ clocks ]
50
51properties:
52  compatible:
53    oneOf:
54      - const: ns8250
55      - const: ns16450
56      - const: ns16550
57      - const: ns16550a
58      - const: ns16850
59      - const: aspeed,ast2400-vuart
60      - const: aspeed,ast2500-vuart
61      - const: intel,xscale-uart
62      - const: mrvl,pxa-uart
63      - const: nuvoton,wpcm450-uart
64      - const: nuvoton,npcm750-uart
65      - const: nuvoton,npcm845-uart
66      - const: nvidia,tegra20-uart
67      - const: nxp,lpc3220-uart
68      - items:
69          - enum:
70              - exar,xr16l2552
71              - exar,xr16l2551
72              - exar,xr16l2550
73          - const: ns8250
74      - items:
75          - enum:
76              - altr,16550-FIFO32
77              - altr,16550-FIFO64
78              - altr,16550-FIFO128
79              - fsl,16550-FIFO64
80              - fsl,ns16550
81              - andestech,uart16550
82              - nxp,lpc1850-uart
83              - opencores,uart16550-rtlsvn105
84              - ti,da830-uart
85          - const: ns16550a
86      - items:
87          - enum:
88              - ns16750
89              - cavium,octeon-3860-uart
90              - xlnx,xps-uart16550-2.00.b
91              - ralink,rt2880-uart
92          - enum:
93              - ns16550 # Deprecated, unless the FIFO really is broken
94              - ns16550a
95      - items:
96          - enum:
97              - ralink,mt7620a-uart
98              - ralink,rt3052-uart
99              - ralink,rt3883-uart
100          - const: ralink,rt2880-uart
101          - enum:
102              - ns16550 # Deprecated, unless the FIFO really is broken
103              - ns16550a
104      - items:
105          - enum:
106              - mediatek,mt7622-btif
107              - mediatek,mt7623-btif
108          - const: mediatek,mtk-btif
109      - items:
110          - const: mrvl,mmp-uart
111          - const: intel,xscale-uart
112      - items:
113          - enum:
114              - nvidia,tegra30-uart
115              - nvidia,tegra114-uart
116              - nvidia,tegra124-uart
117              - nvidia,tegra210-uart
118              - nvidia,tegra186-uart
119              - nvidia,tegra194-uart
120              - nvidia,tegra234-uart
121          - const: nvidia,tegra20-uart
122
123  reg:
124    maxItems: 1
125
126  interrupts:
127    maxItems: 1
128
129  clock-frequency: true
130
131  clocks:
132    maxItems: 1
133
134  resets:
135    maxItems: 1
136
137  current-speed:
138    $ref: /schemas/types.yaml#/definitions/uint32
139    description: The current active speed of the UART.
140
141  reg-offset:
142    $ref: /schemas/types.yaml#/definitions/uint32
143    description: |
144      Offset to apply to the mapbase from the start of the registers.
145
146  reg-shift:
147    description: Quantity to shift the register offsets by.
148
149  reg-io-width:
150    description: |
151      The size (in bytes) of the IO accesses that should be performed on the
152      device. There are some systems that require 32-bit accesses to the
153      UART (e.g. TI davinci).
154
155  used-by-rtas:
156    type: boolean
157    description: |
158      Set to indicate that the port is in use by the OpenFirmware RTAS and
159      should not be registered.
160
161  no-loopback-test:
162    type: boolean
163    description: |
164      Set to indicate that the port does not implement loopback test mode.
165
166  fifo-size:
167    $ref: /schemas/types.yaml#/definitions/uint32
168    description: The fifo size of the UART.
169
170  auto-flow-control:
171    type: boolean
172    description: |
173      One way to enable automatic flow control support. The driver is
174      allowed to detect support for the capability even without this
175      property.
176
177  tx-threshold:
178    description: |
179      Specify the TX FIFO low water indication for parts with programmable
180      TX FIFO thresholds.
181
182  overrun-throttle-ms:
183    description: |
184      How long to pause uart rx when input overrun is encountered.
185
186  rts-gpios: true
187  cts-gpios: true
188  dtr-gpios: true
189  dsr-gpios: true
190  rng-gpios: true
191  dcd-gpios: true
192
193  aspeed,sirq-polarity-sense:
194    $ref: /schemas/types.yaml#/definitions/phandle-array
195    description: |
196      Phandle to aspeed,ast2500-scu compatible syscon alongside register
197      offset and bit number to identify how the SIRQ polarity should be
198      configured. One possible data source is the LPC/eSPI mode bit. Only
199      applicable to aspeed,ast2500-vuart.
200    deprecated: true
201
202  aspeed,lpc-io-reg:
203    $ref: '/schemas/types.yaml#/definitions/uint32'
204    description: |
205      The VUART LPC address.  Only applicable to aspeed,ast2500-vuart.
206
207  aspeed,lpc-interrupts:
208    $ref: "/schemas/types.yaml#/definitions/uint32-array"
209    minItems: 2
210    maxItems: 2
211    description: |
212      A 2-cell property describing the VUART SIRQ number and SIRQ
213      polarity (IRQ_TYPE_LEVEL_LOW or IRQ_TYPE_LEVEL_HIGH).  Only
214      applicable to aspeed,ast2500-vuart.
215
216required:
217  - reg
218  - interrupts
219
220unevaluatedProperties: false
221
222examples:
223  - |
224    serial@80230000 {
225        compatible = "ns8250";
226        reg = <0x80230000 0x100>;
227        interrupts = <10>;
228        reg-shift = <2>;
229        clock-frequency = <48000000>;
230    };
231  - |
232    #include <dt-bindings/gpio/gpio.h>
233    serial@49042000 {
234        compatible = "andestech,uart16550", "ns16550a";
235        reg = <0x49042000 0x400>;
236        interrupts = <80>;
237        clock-frequency = <48000000>;
238        cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
239        rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
240        dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
241        dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
242        dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
243        rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
244    };
245  - |
246    #include <dt-bindings/clock/aspeed-clock.h>
247    #include <dt-bindings/interrupt-controller/irq.h>
248    serial@1e787000 {
249        compatible = "aspeed,ast2500-vuart";
250        reg = <0x1e787000 0x40>;
251        reg-shift = <2>;
252        interrupts = <8>;
253        clocks = <&syscon ASPEED_CLK_APB>;
254        no-loopback-test;
255        aspeed,lpc-io-reg = <0x3f8>;
256        aspeed,lpc-interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
257    };
258
259...
260