1Samsung GPIO and Pin Mux/Config controller
2
3Samsung's ARM based SoC's integrates a GPIO and Pin mux/config hardware
4controller. It controls the input/output settings on the available pads/pins
5and also provides ability to multiplex and configure the output of various
6on-chip controllers onto these pads.
7
8Required Properties:
9- compatible: should be one of the following.
10  - "samsung,s3c2412-pinctrl": for S3C2412-compatible pin-controller,
11  - "samsung,s3c2416-pinctrl": for S3C2416-compatible pin-controller,
12  - "samsung,s3c2440-pinctrl": for S3C2440-compatible pin-controller,
13  - "samsung,s3c2450-pinctrl": for S3C2450-compatible pin-controller,
14  - "samsung,s3c64xx-pinctrl": for S3C64xx-compatible pin-controller,
15  - "samsung,s5pv210-pinctrl": for S5PV210-compatible pin-controller,
16  - "samsung,exynos3250-pinctrl": for Exynos3250 compatible pin-controller.
17  - "samsung,exynos4210-pinctrl": for Exynos4210 compatible pin-controller.
18  - "samsung,exynos4x12-pinctrl": for Exynos4x12 compatible pin-controller.
19  - "samsung,exynos5250-pinctrl": for Exynos5250 compatible pin-controller.
20  - "samsung,exynos5260-pinctrl": for Exynos5260 compatible pin-controller.
21  - "samsung,exynos5410-pinctrl": for Exynos5410 compatible pin-controller.
22  - "samsung,exynos5420-pinctrl": for Exynos5420 compatible pin-controller.
23  - "samsung,exynos5433-pinctrl": for Exynos5433 compatible pin-controller.
24  - "samsung,exynos7-pinctrl": for Exynos7 compatible pin-controller.
25  - "samsung,exynos7885-pinctrl": for Exynos7885 compatible pin-controller.
26  - "samsung,exynos850-pinctrl": for Exynos850 compatible pin-controller.
27  - "samsung,exynosautov9-pinctrl": for ExynosAutov9 compatible pin-controller.
28
29- reg: Base address of the pin controller hardware module and length of
30  the address space it occupies.
31
32  - reg: Second base address of the pin controller if the specific registers
33  of the pin controller are separated into the different base address.
34
35	Eg: GPF[1-5] of Exynos5433 are separated into the two base address.
36	- First base address is for GPAx and GPF[1-5] external interrupt
37	  registers.
38	- Second base address is for GPF[1-5] pinctrl registers.
39
40	pinctrl_0: pinctrl@10580000 {
41		compatible = "samsung,exynos5433-pinctrl";
42		reg = <0x10580000 0x1a20>, <0x11090000 0x100>;
43
44		wakeup-interrupt-controller {
45			compatible = "samsung,exynos7-wakeup-eint";
46			interrupts = <0 16 0>;
47		};
48	};
49
50- Pin banks as child nodes: Pin banks of the controller are represented by child
51  nodes of the controller node. Bank name is taken from name of the node. Each
52  bank node must contain following properties:
53
54  - gpio-controller: identifies the node as a gpio controller and pin bank.
55  - #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
56    binding is used, the amount of cells must be specified as 2. See the below
57    mentioned gpio binding representation for description of particular cells.
58
59	Eg: <&gpx2 6 0>
60	<[phandle of the gpio controller node]
61	[pin number within the gpio controller]
62	[flags]>
63
64	Values for gpio specifier:
65	- Pin number: is a value between 0 to 7.
66	- Flags: 0 - Active High
67		 1 - Active Low
68
69- Pin mux/config groups as child nodes: The pin mux (selecting pin function
70  mode) and pin config (pull up/down, driver strength) settings are represented
71  as child nodes of the pin-controller node. There should be at least one
72  child node and there is no limit on the count of these child nodes. It is
73  also possible for a child node to consist of several further child nodes
74  to allow grouping multiple pinctrl groups into one. The format of second
75  level child nodes is exactly the same as for first level ones and is
76  described below.
77
78  The child node should contain a list of pin(s) on which a particular pin
79  function selection or pin configuration (or both) have to applied. This
80  list of pins is specified using the property name "samsung,pins". There
81  should be at least one pin specified for this property and there is no upper
82  limit on the count of pins that can be specified. The pins are specified
83  using pin names which are derived from the hardware manual of the SoC. As
84  an example, the pins in GPA0 bank of the pin controller can be represented
85  as "gpa0-0", "gpa0-1", "gpa0-2" and so on. The names should be in lower case.
86  The format of the pin names should be (as per the hardware manual)
87  "[pin bank name]-[pin number within the bank]".
88
89  The pin function selection that should be applied on the pins listed in the
90  child node is specified using the "samsung,pin-function" property. The value
91  of this property that should be applied to each of the pins listed in the
92  "samsung,pins" property should be picked from the hardware manual of the SoC
93  for the specified pin group. This property is optional in the child node if
94  no specific function selection is desired for the pins listed in the child
95  node. The value of this property is used as-is to program the pin-controller
96  function selector register of the pin-bank.
97
98  The child node can also optionally specify one or more of the pin
99  configuration that should be applied on all the pins listed in the
100  "samsung,pins" property of the child node. The following pin configuration
101  properties are supported.
102
103  - samsung,pin-val: Initial value of pin output buffer.
104  - samsung,pin-pud: Pull up/down configuration.
105  - samsung,pin-drv: Drive strength configuration.
106  - samsung,pin-pud-pdn: Pull up/down configuration in power down mode.
107  - samsung,pin-drv-pdn: Drive strength configuration in power down mode.
108
109  The values specified by these config properties should be derived from the
110  hardware manual and these values are programmed as-is into the pin
111  pull up/down and driver strength register of the pin-controller.
112
113  Note: A child should include at least a pin function selection property or
114  pin configuration property (one or more) or both.
115
116  The client nodes that require a particular pin function selection and/or
117  pin configuration should use the bindings listed in the "pinctrl-bindings.txt"
118  file.
119
120External GPIO and Wakeup Interrupts:
121
122The controller supports two types of external interrupts over gpio. The first
123is the external gpio interrupt and second is the external wakeup interrupts.
124The difference between the two is that the external wakeup interrupts can be
125used as system wakeup events.
126
127A. External GPIO Interrupts: For supporting external gpio interrupts, the
128   following properties should be specified in the pin-controller device node.
129
130   - interrupts: interrupt specifier for the controller. The format and value of
131     the interrupt specifier depends on the interrupt parent for the controller.
132
133   In addition, following properties must be present in node of every bank
134   of pins supporting GPIO interrupts:
135
136   - interrupt-controller: identifies the controller node as interrupt-parent.
137   - #interrupt-cells: the value of this property should be 2.
138     - First Cell: represents the external gpio interrupt number local to the
139       external gpio interrupt space of the controller.
140     - Second Cell: flags to identify the type of the interrupt
141       - 1 = rising edge triggered
142       - 2 = falling edge triggered
143       - 3 = rising and falling edge triggered
144       - 4 = high level triggered
145       - 8 = low level triggered
146
147B. External Wakeup Interrupts: For supporting external wakeup interrupts, a
148   child node representing the external wakeup interrupt controller should be
149   included in the pin-controller device node.
150
151   Only one pin-controller device node can include external wakeup interrupts
152   child node (in other words, only one External Wakeup Interrupts
153   pin-controller is supported).
154
155   This child node should include following properties:
156
157   - compatible: identifies the type of the external wakeup interrupt controller
158     The possible values are:
159     - samsung,s3c2410-wakeup-eint: represents wakeup interrupt controller
160       found on Samsung S3C24xx SoCs except S3C2412 and S3C2413,
161     - samsung,s3c2412-wakeup-eint: represents wakeup interrupt controller
162       found on Samsung S3C2412 and S3C2413 SoCs,
163     - samsung,s3c64xx-wakeup-eint: represents wakeup interrupt controller
164       found on Samsung S3C64xx SoCs,
165     - samsung,s5pv210-wakeup-eint: represents wakeup interrupt controller
166       found on Samsung S5Pv210 SoCs,
167     - samsung,exynos4210-wakeup-eint: represents wakeup interrupt controller
168       found on Samsung Exynos4210 and S5PC110/S5PV210 SoCs.
169     - samsung,exynos7-wakeup-eint: represents wakeup interrupt controller
170       found on Samsung Exynos7 SoC.
171   - interrupts: interrupt used by multiplexed wakeup interrupts.
172
173   In addition, following properties must be present in node of every bank
174   of pins supporting wake-up interrupts:
175
176   - interrupt-controller: identifies the node as interrupt-parent.
177   - #interrupt-cells: the value of this property should be 2
178     - First Cell: represents the external wakeup interrupt number local to
179       the external wakeup interrupt space of the controller.
180     - Second Cell: flags to identify the type of the interrupt
181       - 1 = rising edge triggered
182       - 2 = falling edge triggered
183       - 3 = rising and falling edge triggered
184       - 4 = high level triggered
185       - 8 = low level triggered
186
187   Node of every bank of pins supporting direct wake-up interrupts (without
188   multiplexing) must contain following properties:
189
190   - interrupts: interrupts of the interrupt parent which are used for external
191     wakeup interrupts from pins of the bank, must contain interrupts for all
192     pins of the bank.
193
194Aliases:
195
196All the pin controller nodes should be represented in the aliases node using
197the following format 'pinctrl{n}' where n is a unique number for the alias.
198
199Aliases for controllers compatible with "samsung,exynos7-pinctrl":
200- pinctrl0: pin controller of ALIVE block,
201- pinctrl1: pin controller of BUS0 block,
202- pinctrl2: pin controller of NFC block,
203- pinctrl3: pin controller of TOUCH block,
204- pinctrl4: pin controller of FF block,
205- pinctrl5: pin controller of ESE block,
206- pinctrl6: pin controller of FSYS0 block,
207- pinctrl7: pin controller of FSYS1 block,
208- pinctrl8: pin controller of BUS1 block,
209- pinctrl9: pin controller of AUDIO block,
210
211Example: A pin-controller node with pin banks:
212
213	pinctrl_0: pinctrl@11400000 {
214		compatible = "samsung,exynos4210-pinctrl";
215		reg = <0x11400000 0x1000>;
216		interrupts = <0 47 0>;
217
218		/* ... */
219
220		/* Pin bank without external interrupts */
221		gpy0: gpy0 {
222			gpio-controller;
223			#gpio-cells = <2>;
224		};
225
226		/* ... */
227
228		/* Pin bank with external GPIO or muxed wake-up interrupts */
229		gpj0: gpj0 {
230			gpio-controller;
231			#gpio-cells = <2>;
232
233			interrupt-controller;
234			#interrupt-cells = <2>;
235		};
236
237		/* ... */
238
239		/* Pin bank with external direct wake-up interrupts */
240		gpx0: gpx0 {
241			gpio-controller;
242			#gpio-cells = <2>;
243
244			interrupt-controller;
245			interrupt-parent = <&gic>;
246			interrupts = <0 16 0>, <0 17 0>, <0 18 0>, <0 19 0>,
247				     <0 20 0>, <0 21 0>, <0 22 0>, <0 23 0>;
248			#interrupt-cells = <2>;
249		};
250
251		/* ... */
252	};
253
254Example 1: A pin-controller node with pin groups.
255
256	#include <dt-bindings/pinctrl/samsung.h>
257
258	pinctrl_0: pinctrl@11400000 {
259		compatible = "samsung,exynos4210-pinctrl";
260		reg = <0x11400000 0x1000>;
261		interrupts = <0 47 0>;
262
263		/* ... */
264
265		uart0_data: uart0-data {
266			samsung,pins = "gpa0-0", "gpa0-1";
267			samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
268			samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
269			samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
270		};
271
272		uart0_fctl: uart0-fctl {
273			samsung,pins = "gpa0-2", "gpa0-3";
274			samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
275			samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
276			samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
277		};
278
279		uart1_data: uart1-data {
280			samsung,pins = "gpa0-4", "gpa0-5";
281			samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
282			samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
283			samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
284		};
285
286		uart1_fctl: uart1-fctl {
287			samsung,pins = "gpa0-6", "gpa0-7";
288			samsung,pin-function = <EXYNOS_PIN_FUNC_2>;
289			samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
290			samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
291		};
292
293		i2c2_bus: i2c2-bus {
294			samsung,pins = "gpa0-6", "gpa0-7";
295			samsung,pin-function = <EXYNOS_PIN_FUNC_3>;
296			samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
297			samsung,pin-drv = <EXYNOS4_PIN_DRV_LV1>;
298		};
299
300		sd4_bus8: sd4-bus-width8 {
301			part-1 {
302				samsung,pins = "gpk0-3", "gpk0-4",
303						"gpk0-5", "gpk0-6";
304				samsung,pin-function = <EXYNOS_PIN_FUNC_3>;
305				samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
306				samsung,pin-drv = <EXYNOS4_PIN_DRV_LV4>;
307			};
308			part-2 {
309				samsung,pins = "gpk1-3", "gpk1-4",
310						"gpk1-5", "gpk1-6";
311				samsung,pin-function = <EXYNOS_PIN_FUNC_4>;
312				samsung,pin-pud = <EXYNOS_PIN_PULL_UP>;
313				samsung,pin-drv = <EXYNOS4_PIN_DRV_LV4>;
314			};
315		};
316	};
317
318Example 2: A pin-controller node with external wakeup interrupt controller node.
319
320	pinctrl_1: pinctrl@11000000 {
321		compatible = "samsung,exynos4210-pinctrl";
322		reg = <0x11000000 0x1000>;
323		interrupts = <0 46 0>
324
325		/* ... */
326
327		wakeup-interrupt-controller {
328			compatible = "samsung,exynos4210-wakeup-eint";
329			interrupt-parent = <&gic>;
330			interrupts = <0 32 0>;
331		};
332	};
333
334Example 3: A uart client node that supports 'default' and 'flow-control' states.
335
336	uart@13800000 {
337		compatible = "samsung,exynos4210-uart";
338		reg = <0x13800000 0x100>;
339		interrupts = <0 52 0>;
340		pinctrl-names = "default", "flow-control;
341		pinctrl-0 = <&uart0_data>;
342		pinctrl-1 = <&uart0_data>, <&uart0_fctl>;
343	};
344
345Example 4: Set up the default pin state for uart controller.
346
347	static int s3c24xx_serial_probe(struct platform_device *pdev) {
348		struct pinctrl *pinctrl;
349
350		/* ... */
351
352		pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
353	}
354
355Example 5: A display port client node that supports 'default' pinctrl state
356	   and gpio binding.
357
358	display-port-controller {
359		/* ... */
360
361		samsung,hpd-gpio = <&gpx2 6 0>;
362		pinctrl-names = "default";
363		pinctrl-0 = <&dp_hpd>;
364	};
365
366Example 6: Request the gpio for display port controller
367
368	static int exynos_dp_probe(struct platform_device *pdev)
369	{
370		int hpd_gpio, ret;
371		struct device *dev = &pdev->dev;
372		struct device_node *dp_node = dev->of_node;
373
374		/* ... */
375
376		hpd_gpio = of_get_named_gpio(dp_node, "samsung,hpd-gpio", 0);
377
378		/* ... */
379
380		ret = devm_gpio_request_one(&pdev->dev, hpd_gpio, GPIOF_IN,
381					    "hpd_gpio");
382		/* ... */
383	}
384