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
7 title: UART (Universal Asynchronous Receiver/Transmitter)
8
9 maintainers:
10 - devicetree@vger.kernel.org
11
12 allOf:
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
52 properties:
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
221 required:
222 - reg
223 - interrupts
224
225 unevaluatedProperties: false
226
227 examples:
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 ...
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.