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