xref: /linux/Documentation/devicetree/bindings/serial/8250.yaml (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0) 
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  - $ref: /schemas/memory-controllers/mc-peripheral-props.yaml#
15  - if:
16      anyOf:
17        - required:
18            - aspeed,lpc-io-reg
19        - required:
20            - aspeed,lpc-interrupts
21        - required:
22            - aspeed,sirq-polarity-sense
23    then:
24      properties:
25        compatible:
26          const: aspeed,ast2500-vuart
27  - if:
28      properties:
29        compatible:
30          const: mrvl,mmp-uart
31    then:
32      properties:
33        reg-shift:
34          const: 2
35      required:
36        - reg-shift
37  - if:
38      not:
39        properties:
40          compatible:
41            items:
42              - enum:
43                  - ns8250
44                  - ns16450
45                  - ns16550
46                  - ns16550a
47    then:
48      anyOf:
49        - required: [ clock-frequency ]
50        - required: [ clocks ]
51
52properties:
53  compatible:
54    oneOf:
55      - const: ns8250
56      - const: ns16450
57      - const: ns16550
58      - const: ns16550a
59      - const: ns16850
60      - const: aspeed,ast2400-vuart
61      - const: aspeed,ast2500-vuart
62      - const: intel,xscale-uart
63      - const: mrvl,pxa-uart
64      - const: nuvoton,wpcm450-uart
65      - const: nuvoton,npcm750-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              - nuvoton,npcm845-uart
98          - const: nuvoton,npcm750-uart
99      - items:
100          - enum:
101              - ralink,mt7620a-uart
102              - ralink,rt3052-uart
103              - ralink,rt3883-uart
104          - const: ralink,rt2880-uart
105          - enum:
106              - ns16550 # Deprecated, unless the FIFO really is broken
107              - ns16550a
108      - items:
109          - enum:
110              - mediatek,mt7622-btif
111              - mediatek,mt7623-btif
112          - const: mediatek,mtk-btif
113      - items:
114          - const: mrvl,mmp-uart
115          - const: intel,xscale-uart
116      - items:
117          - enum:
118              - nvidia,tegra30-uart
119              - nvidia,tegra114-uart
120              - nvidia,tegra124-uart
121              - nvidia,tegra210-uart
122              - nvidia,tegra186-uart
123              - nvidia,tegra194-uart
124              - nvidia,tegra234-uart
125          - const: nvidia,tegra20-uart
126
127  reg:
128    maxItems: 1
129
130  interrupts:
131    maxItems: 1
132
133  clock-frequency: true
134
135  clocks:
136    maxItems: 1
137
138  resets:
139    maxItems: 1
140
141  current-speed:
142    $ref: /schemas/types.yaml#/definitions/uint32
143    description: The current active speed of the UART.
144
145  reg-offset:
146    $ref: /schemas/types.yaml#/definitions/uint32
147    description: |
148      Offset to apply to the mapbase from the start of the registers.
149
150  reg-shift:
151    description: Quantity to shift the register offsets by.
152
153  reg-io-width:
154    description: |
155      The size (in bytes) of the IO accesses that should be performed on the
156      device. There are some systems that require 32-bit accesses to the
157      UART (e.g. TI davinci).
158
159  used-by-rtas:
160    type: boolean
161    description: |
162      Set to indicate that the port is in use by the OpenFirmware RTAS and
163      should not be registered.
164
165  no-loopback-test:
166    type: boolean
167    description: |
168      Set to indicate that the port does not implement loopback test mode.
169
170  fifo-size:
171    $ref: /schemas/types.yaml#/definitions/uint32
172    description: The fifo size of the UART.
173
174  auto-flow-control:
175    type: boolean
176    description: |
177      One way to enable automatic flow control support. The driver is
178      allowed to detect support for the capability even without this
179      property.
180
181  tx-threshold:
182    description: |
183      Specify the TX FIFO low water indication for parts with programmable
184      TX FIFO thresholds.
185
186  overrun-throttle-ms:
187    description: |
188      How long to pause uart rx when input overrun is encountered.
189
190  rts-gpios: true
191  cts-gpios: true
192  dtr-gpios: true
193  dsr-gpios: true
194  rng-gpios: true
195  dcd-gpios: true
196
197  aspeed,sirq-polarity-sense:
198    $ref: /schemas/types.yaml#/definitions/phandle-array
199    description: |
200      Phandle to aspeed,ast2500-scu compatible syscon alongside register
201      offset and bit number to identify how the SIRQ polarity should be
202      configured. One possible data source is the LPC/eSPI mode bit. Only
203      applicable to aspeed,ast2500-vuart.
204    deprecated: true
205
206  aspeed,lpc-io-reg:
207    $ref: /schemas/types.yaml#/definitions/uint32-array
208    maxItems: 1
209    description: |
210      The VUART LPC address.  Only applicable to aspeed,ast2500-vuart.
211
212  aspeed,lpc-interrupts:
213    $ref: /schemas/types.yaml#/definitions/uint32-array
214    minItems: 2
215    maxItems: 2
216    description: |
217      A 2-cell property describing the VUART SIRQ number and SIRQ
218      polarity (IRQ_TYPE_LEVEL_LOW or IRQ_TYPE_LEVEL_HIGH).  Only
219      applicable to aspeed,ast2500-vuart.
220
221required:
222  - reg
223  - interrupts
224
225unevaluatedProperties: false
226
227examples:
228  - |
229    serial@80230000 {
230        compatible = "ns8250";
231        reg = <0x80230000 0x100>;
232        interrupts = <10>;
233        reg-shift = <2>;
234        clock-frequency = <48000000>;
235    };
236  - |
237    #include <dt-bindings/gpio/gpio.h>
238    serial@49042000 {
239        compatible = "andestech,uart16550", "ns16550a";
240        reg = <0x49042000 0x400>;
241        interrupts = <80>;
242        clock-frequency = <48000000>;
243        cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
244        rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
245        dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
246        dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
247        dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
248        rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
249    };
250  - |
251    #include <dt-bindings/clock/aspeed-clock.h>
252    #include <dt-bindings/interrupt-controller/irq.h>
253    serial@1e787000 {
254        compatible = "aspeed,ast2500-vuart";
255        reg = <0x1e787000 0x40>;
256        reg-shift = <2>;
257        interrupts = <8>;
258        clocks = <&syscon ASPEED_CLK_APB>;
259        no-loopback-test;
260        aspeed,lpc-io-reg = <0x3f8>;
261        aspeed,lpc-interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
262    };
263
264...
265