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Documentation / devicetree / bindings / pinctrl / samsung-pinctrl.txt




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Based on kernel version 3.9. Page generated on 2013-05-02 23:00 EST.

1	Samsung GPIO and Pin Mux/Config controller
2	
3	Samsung's ARM based SoC's integrates a GPIO and Pin mux/config hardware
4	controller. It controls the input/output settings on the available pads/pins
5	and also provides ability to multiplex and configure the output of various
6	on-chip controllers onto these pads.
7	
8	Required Properties:
9	- compatible: should be one of the following.
10	  - "samsung,exynos4210-pinctrl": for Exynos4210 compatible pin-controller.
11	  - "samsung,exynos4x12-pinctrl": for Exynos4x12 compatible pin-controller.
12	  - "samsung,exynos5250-pinctrl": for Exynos5250 compatible pin-controller.
13	
14	- reg: Base address of the pin controller hardware module and length of
15	  the address space it occupies.
16	
17	- Pin banks as child nodes: Pin banks of the controller are represented by child
18	  nodes of the controller node. Bank name is taken from name of the node. Each
19	  bank node must contain following properties:
20	
21	  - gpio-controller: identifies the node as a gpio controller and pin bank.
22	  - #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
23	    binding is used, the amount of cells must be specified as 2. See generic
24	    GPIO binding documentation for description of particular cells.
25	
26	- Pin mux/config groups as child nodes: The pin mux (selecting pin function
27	  mode) and pin config (pull up/down, driver strength) settings are represented
28	  as child nodes of the pin-controller node. There should be atleast one
29	  child node and there is no limit on the count of these child nodes.
30	
31	  The child node should contain a list of pin(s) on which a particular pin
32	  function selection or pin configuration (or both) have to applied. This
33	  list of pins is specified using the property name "samsung,pins". There
34	  should be atleast one pin specfied for this property and there is no upper
35	  limit on the count of pins that can be specified. The pins are specified
36	  using pin names which are derived from the hardware manual of the SoC. As
37	  an example, the pins in GPA0 bank of the pin controller can be represented
38	  as "gpa0-0", "gpa0-1", "gpa0-2" and so on. The names should be in lower case.
39	  The format of the pin names should be (as per the hardware manual)
40	  "[pin bank name]-[pin number within the bank]".
41	
42	  The pin function selection that should be applied on the pins listed in the
43	  child node is specified using the "samsung,pin-function" property. The value
44	  of this property that should be applied to each of the pins listed in the
45	  "samsung,pins" property should be picked from the hardware manual of the SoC
46	  for the specified pin group. This property is optional in the child node if
47	  no specific function selection is desired for the pins listed in the child
48	  node. The value of this property is used as-is to program the pin-controller
49	  function selector register of the pin-bank.
50	
51	  The child node can also optionally specify one or more of the pin
52	  configuration that should be applied on all the pins listed in the
53	  "samsung,pins" property of the child node. The following pin configuration
54	  properties are supported.
55	
56	  - samsung,pin-pud: Pull up/down configuration.
57	  - samsung,pin-drv: Drive strength configuration.
58	  - samsung,pin-pud-pdn: Pull up/down configuration in power down mode.
59	  - samsung,pin-drv-pdn: Drive strength configuration in power down mode.
60	
61	  The values specified by these config properties should be derived from the
62	  hardware manual and these values are programmed as-is into the pin
63	  pull up/down and driver strength register of the pin-controller.
64	
65	  Note: A child should include atleast a pin function selection property or
66	  pin configuration property (one or more) or both.
67	
68	  The client nodes that require a particular pin function selection and/or
69	  pin configuration should use the bindings listed in the "pinctrl-bindings.txt"
70	  file.
71	
72	External GPIO and Wakeup Interrupts:
73	
74	The controller supports two types of external interrupts over gpio. The first
75	is the external gpio interrupt and second is the external wakeup interrupts.
76	The difference between the two is that the external wakeup interrupts can be
77	used as system wakeup events.
78	
79	A. External GPIO Interrupts: For supporting external gpio interrupts, the
80	   following properties should be specified in the pin-controller device node.
81	
82	   - interrupt-parent: phandle of the interrupt parent to which the external
83	     GPIO interrupts are forwarded to.
84	   - interrupts: interrupt specifier for the controller. The format and value of
85	     the interrupt specifier depends on the interrupt parent for the controller.
86	
87	   In addition, following properties must be present in node of every bank
88	   of pins supporting GPIO interrupts:
89	
90	   - interrupt-controller: identifies the controller node as interrupt-parent.
91	   - #interrupt-cells: the value of this property should be 2.
92	     - First Cell: represents the external gpio interrupt number local to the
93	       external gpio interrupt space of the controller.
94	     - Second Cell: flags to identify the type of the interrupt
95	       - 1 = rising edge triggered
96	       - 2 = falling edge triggered
97	       - 3 = rising and falling edge triggered
98	       - 4 = high level triggered
99	       - 8 = low level triggered
100	
101	B. External Wakeup Interrupts: For supporting external wakeup interrupts, a
102	   child node representing the external wakeup interrupt controller should be
103	   included in the pin-controller device node. This child node should include
104	   the following properties.
105	
106	   - compatible: identifies the type of the external wakeup interrupt controller
107	     The possible values are:
108	     - samsung,exynos4210-wakeup-eint: represents wakeup interrupt controller
109	       found on Samsung Exynos4210 SoC.
110	   - interrupt-parent: phandle of the interrupt parent to which the external
111	     wakeup interrupts are forwarded to.
112	   - interrupts: interrupt used by multiplexed wakeup interrupts.
113	
114	   In addition, following properties must be present in node of every bank
115	   of pins supporting wake-up interrupts:
116	
117	   - interrupt-controller: identifies the node as interrupt-parent.
118	   - #interrupt-cells: the value of this property should be 2
119	     - First Cell: represents the external wakeup interrupt number local to
120	       the external wakeup interrupt space of the controller.
121	     - Second Cell: flags to identify the type of the interrupt
122	       - 1 = rising edge triggered
123	       - 2 = falling edge triggered
124	       - 3 = rising and falling edge triggered
125	       - 4 = high level triggered
126	       - 8 = low level triggered
127	
128	   Node of every bank of pins supporting direct wake-up interrupts (without
129	   multiplexing) must contain following properties:
130	
131	   - interrupt-parent: phandle of the interrupt parent to which the external
132	     wakeup interrupts are forwarded to.
133	   - interrupts: interrupts of the interrupt parent which are used for external
134	     wakeup interrupts from pins of the bank, must contain interrupts for all
135	     pins of the bank.
136	
137	Aliases:
138	
139	All the pin controller nodes should be represented in the aliases node using
140	the following format 'pinctrl{n}' where n is a unique number for the alias.
141	
142	Example: A pin-controller node with pin banks:
143	
144		pinctrl_0: pinctrl@11400000 {
145			compatible = "samsung,exynos4210-pinctrl";
146			reg = <0x11400000 0x1000>;
147			interrupts = <0 47 0>;
148	
149			/* ... */
150	
151			/* Pin bank without external interrupts */
152			gpy0: gpy0 {
153				gpio-controller;
154				#gpio-cells = <2>;
155			};
156	
157			/* ... */
158	
159			/* Pin bank with external GPIO or muxed wake-up interrupts */
160			gpj0: gpj0 {
161				gpio-controller;
162				#gpio-cells = <2>;
163	
164				interrupt-controller;
165				#interrupt-cells = <2>;
166			};
167	
168			/* ... */
169	
170			/* Pin bank with external direct wake-up interrupts */
171			gpx0: gpx0 {
172				gpio-controller;
173				#gpio-cells = <2>;
174	
175				interrupt-controller;
176				interrupt-parent = <&gic>;
177				interrupts = <0 16 0>, <0 17 0>, <0 18 0>, <0 19 0>,
178					     <0 20 0>, <0 21 0>, <0 22 0>, <0 23 0>;
179				#interrupt-cells = <2>;
180			};
181	
182			/* ... */
183		};
184	
185	Example 1: A pin-controller node with pin groups.
186	
187		pinctrl_0: pinctrl@11400000 {
188			compatible = "samsung,exynos4210-pinctrl";
189			reg = <0x11400000 0x1000>;
190			interrupts = <0 47 0>;
191	
192			/* ... */
193	
194			uart0_data: uart0-data {
195				samsung,pins = "gpa0-0", "gpa0-1";
196				samsung,pin-function = <2>;
197				samsung,pin-pud = <0>;
198				samsung,pin-drv = <0>;
199			};
200	
201			uart0_fctl: uart0-fctl {
202				samsung,pins = "gpa0-2", "gpa0-3";
203				samsung,pin-function = <2>;
204				samsung,pin-pud = <0>;
205				samsung,pin-drv = <0>;
206			};
207	
208			uart1_data: uart1-data {
209				samsung,pins = "gpa0-4", "gpa0-5";
210				samsung,pin-function = <2>;
211				samsung,pin-pud = <0>;
212				samsung,pin-drv = <0>;
213			};
214	
215			uart1_fctl: uart1-fctl {
216				samsung,pins = "gpa0-6", "gpa0-7";
217				samsung,pin-function = <2>;
218				samsung,pin-pud = <0>;
219				samsung,pin-drv = <0>;
220			};
221	
222			i2c2_bus: i2c2-bus {
223				samsung,pins = "gpa0-6", "gpa0-7";
224				samsung,pin-function = <3>;
225				samsung,pin-pud = <3>;
226				samsung,pin-drv = <0>;
227			};
228		};
229	
230	Example 2: A pin-controller node with external wakeup interrupt controller node.
231	
232		pinctrl_1: pinctrl@11000000 {
233			compatible = "samsung,exynos4210-pinctrl";
234			reg = <0x11000000 0x1000>;
235			interrupts = <0 46 0>
236	
237			/* ... */
238	
239			wakeup-interrupt-controller {
240				compatible = "samsung,exynos4210-wakeup-eint";
241				interrupt-parent = <&gic>;
242				interrupts = <0 32 0>;
243			};
244		};
245	
246	Example 3: A uart client node that supports 'default' and 'flow-control' states.
247	
248		uart@13800000 {
249			compatible = "samsung,exynos4210-uart";
250			reg = <0x13800000 0x100>;
251			interrupts = <0 52 0>;
252			pinctrl-names = "default", "flow-control;
253			pinctrl-0 = <&uart0_data>;
254			pinctrl-1 = <&uart0_data &uart0_fctl>;
255		};
256	
257	Example 4: Set up the default pin state for uart controller.
258	
259		static int s3c24xx_serial_probe(struct platform_device *pdev) {
260			struct pinctrl *pinctrl;
261	
262			/* ... */
263	
264			pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
265		}
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