1NXP i.MX System Controller Firmware (SCFW)
2--------------------------------------------------------------------
3
4The System Controller Firmware (SCFW) is a low-level system function
5which runs on a dedicated Cortex-M core to provide power, clock, and
6resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
7(QM, QP), and i.MX8QX (QXP, DX).
8
9The AP communicates with the SC using a multi-ported MU module found
10in the LSIO subsystem. The current definition of this MU module provides
115 remote AP connections to the SC to support up to 5 execution environments
12(TZ, HV, standard Linux, etc.). The SC side of this MU module interfaces
13with the LSIO DSC IP bus. The SC firmware will communicate with this MU
14using the MSI bus.
15
16System Controller Device Node:
17============================================================
18
19The scu node with the following properties shall be under the /firmware/ node.
20
21Required properties:
22-------------------
23- compatible:	should be "fsl,imx-scu".
24- mbox-names:	should include "tx0", "tx1", "tx2", "tx3",
25			       "rx0", "rx1", "rx2", "rx3";
26		include "gip3" if want to support general MU interrupt.
27- mboxes:	List of phandle of 4 MU channels for tx, 4 MU channels for
28		rx, and 1 optional MU channel for general interrupt.
29		All MU channels must be in the same MU instance.
30		Cross instances are not allowed. The MU instance can only
31		be one of LSIO MU0~M4 for imx8qxp and imx8qm. Users need
32		to make sure use the one which is not conflict with other
33		execution environments. e.g. ATF.
34		Note:
35		Channel 0 must be "tx0" or "rx0".
36		Channel 1 must be "tx1" or "rx1".
37		Channel 2 must be "tx2" or "rx2".
38		Channel 3 must be "tx3" or "rx3".
39		General interrupt rx channel must be "gip3".
40		e.g.
41		mboxes = <&lsio_mu1 0 0
42			  &lsio_mu1 0 1
43			  &lsio_mu1 0 2
44			  &lsio_mu1 0 3
45			  &lsio_mu1 1 0
46			  &lsio_mu1 1 1
47			  &lsio_mu1 1 2
48			  &lsio_mu1 1 3
49			  &lsio_mu1 3 3>;
50		See Documentation/devicetree/bindings/mailbox/fsl,mu.yaml
51		for detailed mailbox binding.
52
53Note: Each mu which supports general interrupt should have an alias correctly
54numbered in "aliases" node.
55e.g.
56aliases {
57	mu1 = &lsio_mu1;
58};
59
60i.MX SCU Client Device Node:
61============================================================
62
63Client nodes are maintained as children of the relevant IMX-SCU device node.
64
65Power domain bindings based on SCU Message Protocol
66------------------------------------------------------------
67
68This binding for the SCU power domain providers uses the generic power
69domain binding[2].
70
71Required properties:
72- compatible:		Should be one of:
73			  "fsl,imx8qm-scu-pd",
74			  "fsl,imx8qxp-scu-pd"
75			followed by "fsl,scu-pd"
76
77- #power-domain-cells:	Must be 1. Contains the Resource ID used by
78			SCU commands.
79			See detailed Resource ID list from:
80			include/dt-bindings/firmware/imx/rsrc.h
81
82Clock bindings based on SCU Message Protocol
83------------------------------------------------------------
84
85This binding uses the common clock binding[1].
86
87Required properties:
88- compatible:		Should be one of:
89			  "fsl,imx8qm-clk"
90			  "fsl,imx8qxp-clk"
91			followed by "fsl,scu-clk"
92- #clock-cells:		Should be 2.
93			Contains the Resource and Clock ID value.
94- clocks:		List of clock specifiers, must contain an entry for
95			each required entry in clock-names
96- clock-names:		Should include entries "xtal_32KHz", "xtal_24MHz"
97
98The clock consumer should specify the desired clock by having the clock
99ID in its "clocks" phandle cell.
100
101See the full list of clock IDs from:
102include/dt-bindings/clock/imx8qxp-clock.h
103
104Pinctrl bindings based on SCU Message Protocol
105------------------------------------------------------------
106
107This binding uses the i.MX common pinctrl binding[3].
108
109Required properties:
110- compatible:		Should be one of:
111			"fsl,imx8qm-iomuxc",
112			"fsl,imx8qxp-iomuxc",
113			"fsl,imx8dxl-iomuxc".
114
115Required properties for Pinctrl sub nodes:
116- fsl,pins:		Each entry consists of 3 integers which represents
117			the mux and config setting for one pin. The first 2
118			integers <pin_id mux_mode> are specified using a
119			PIN_FUNC_ID macro, which can be found in
120			<dt-bindings/pinctrl/pads-imx8qm.h>,
121			<dt-bindings/pinctrl/pads-imx8qxp.h>,
122			<dt-bindings/pinctrl/pads-imx8dxl.h>.
123			The last integer CONFIG is the pad setting value like
124			pull-up on this pin.
125
126			Please refer to i.MX8QXP Reference Manual for detailed
127			CONFIG settings.
128
129[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
130[2] Documentation/devicetree/bindings/power/power-domain.yaml
131[3] Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt
132
133RTC bindings based on SCU Message Protocol
134------------------------------------------------------------
135
136Required properties:
137- compatible: should be "fsl,imx8qxp-sc-rtc";
138
139OCOTP bindings based on SCU Message Protocol
140------------------------------------------------------------
141Required properties:
142- compatible:		Should be one of:
143			"fsl,imx8qm-scu-ocotp",
144			"fsl,imx8qxp-scu-ocotp".
145- #address-cells:	Must be 1. Contains byte index
146- #size-cells:		Must be 1. Contains byte length
147
148Optional Child nodes:
149
150- Data cells of ocotp:
151  Detailed bindings are described in bindings/nvmem/nvmem.txt
152
153Watchdog bindings based on SCU Message Protocol
154------------------------------------------------------------
155
156Required properties:
157- compatible: should be:
158              "fsl,imx8qxp-sc-wdt"
159              followed by "fsl,imx-sc-wdt";
160Optional properties:
161- timeout-sec: contains the watchdog timeout in seconds.
162
163SCU key bindings based on SCU Message Protocol
164------------------------------------------------------------
165
166Required properties:
167- compatible: should be:
168              "fsl,imx8qxp-sc-key"
169              followed by "fsl,imx-sc-key";
170- linux,keycodes: See Documentation/devicetree/bindings/input/input.yaml
171
172Thermal bindings based on SCU Message Protocol
173------------------------------------------------------------
174
175Required properties:
176- compatible:			Should be :
177				  "fsl,imx8qxp-sc-thermal"
178				followed by "fsl,imx-sc-thermal";
179
180- #thermal-sensor-cells:	See Documentation/devicetree/bindings/thermal/thermal-sensor.yaml
181				for a description.
182
183Example (imx8qxp):
184-------------
185aliases {
186	mu1 = &lsio_mu1;
187};
188
189lsio_mu1: mailbox@5d1c0000 {
190	...
191	#mbox-cells = <2>;
192};
193
194firmware {
195	scu {
196		compatible = "fsl,imx-scu";
197		mbox-names = "tx0", "tx1", "tx2", "tx3",
198			     "rx0", "rx1", "rx2", "rx3",
199			     "gip3";
200		mboxes = <&lsio_mu1 0 0
201			  &lsio_mu1 0 1
202			  &lsio_mu1 0 2
203			  &lsio_mu1 0 3
204			  &lsio_mu1 1 0
205			  &lsio_mu1 1 1
206			  &lsio_mu1 1 2
207			  &lsio_mu1 1 3
208			  &lsio_mu1 3 3>;
209
210		clk: clk {
211			compatible = "fsl,imx8qxp-clk", "fsl,scu-clk";
212			#clock-cells = <2>;
213		};
214
215		iomuxc {
216			compatible = "fsl,imx8qxp-iomuxc";
217
218			pinctrl_lpuart0: lpuart0grp {
219				fsl,pins = <
220					SC_P_UART0_RX_ADMA_UART0_RX	0x06000020
221					SC_P_UART0_TX_ADMA_UART0_TX	0x06000020
222				>;
223			};
224			...
225		};
226
227		ocotp: imx8qx-ocotp {
228			compatible = "fsl,imx8qxp-scu-ocotp";
229			#address-cells = <1>;
230			#size-cells = <1>;
231
232			fec_mac0: mac@2c4 {
233				reg = <0x2c4 8>;
234			};
235		};
236
237		pd: imx8qx-pd {
238			compatible = "fsl,imx8qxp-scu-pd", "fsl,scu-pd";
239			#power-domain-cells = <1>;
240		};
241
242		rtc: rtc {
243			compatible = "fsl,imx8qxp-sc-rtc";
244		};
245
246		scu_key: scu-key {
247			compatible = "fsl,imx8qxp-sc-key", "fsl,imx-sc-key";
248			linux,keycodes = <KEY_POWER>;
249		};
250
251		watchdog {
252			compatible = "fsl,imx8qxp-sc-wdt", "fsl,imx-sc-wdt";
253			timeout-sec = <60>;
254		};
255
256		tsens: thermal-sensor {
257			compatible = "fsl,imx8qxp-sc-thermal", "fsl,imx-sc-thermal";
258			#thermal-sensor-cells = <1>;
259		};
260	};
261};
262
263serial@5a060000 {
264	...
265	pinctrl-names = "default";
266	pinctrl-0 = <&pinctrl_lpuart0>;
267	clocks = <&uart0_clk IMX_SC_R_UART_0 IMX_SC_PM_CLK_PER>;
268	clock-names = "ipg";
269	power-domains = <&pd IMX_SC_R_UART_0>;
270};
271