1/* $NetBSD: fdt_pinctrl.c,v 1.10 2019/10/01 23:32:52 jmcneill Exp $ */
2
3/*-
4 * Copyright (c) 2019 Jason R. Thorpe
5 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
6 * Copyright (c) 2015 Martin Fouts
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__KERNEL_RCSID(0, "$NetBSD: fdt_pinctrl.c,v 1.10 2019/10/01 23:32:52 jmcneill Exp $");
33
34#include <sys/param.h>
35#include <sys/bus.h>
36#include <sys/gpio.h>
37#include <sys/kmem.h>
38#include <sys/queue.h>
39
40#include <libfdt.h>
41#include <dev/fdt/fdtvar.h>
42
43struct fdtbus_pinctrl_controller {
44	device_t pc_dev;
45	int pc_phandle;
46	const struct fdtbus_pinctrl_controller_func *pc_funcs;
47
48	LIST_ENTRY(fdtbus_pinctrl_controller) pc_next;
49};
50
51static LIST_HEAD(, fdtbus_pinctrl_controller) fdtbus_pinctrl_controllers =
52    LIST_HEAD_INITIALIZER(fdtbus_pinctrl_controllers);
53
54int
55fdtbus_register_pinctrl_config(device_t dev, int phandle,
56    const struct fdtbus_pinctrl_controller_func *funcs)
57{
58	struct fdtbus_pinctrl_controller *pc;
59
60	pc = kmem_alloc(sizeof(*pc), KM_SLEEP);
61	pc->pc_dev = dev;
62	pc->pc_phandle = phandle;
63	pc->pc_funcs = funcs;
64
65	LIST_INSERT_HEAD(&fdtbus_pinctrl_controllers, pc, pc_next);
66
67	return 0;
68}
69
70static struct fdtbus_pinctrl_controller *
71fdtbus_pinctrl_lookup(int phandle)
72{
73	struct fdtbus_pinctrl_controller *pc;
74
75	LIST_FOREACH(pc, &fdtbus_pinctrl_controllers, pc_next) {
76		if (pc->pc_phandle == phandle)
77			return pc;
78	}
79
80	return NULL;
81}
82
83int
84fdtbus_pinctrl_set_config_index(int phandle, u_int index)
85{
86	struct fdtbus_pinctrl_controller *pc;
87	const u_int *pinctrl_data;
88	char buf[16];
89	u_int xref, pinctrl_cells;
90	int len, error;
91
92	snprintf(buf, sizeof(buf), "pinctrl-%u", index);
93
94	pinctrl_data = fdtbus_get_prop(phandle, buf, &len);
95	if (pinctrl_data == NULL)
96		return ENOENT;
97
98	while (len > 0) {
99		xref = fdtbus_get_phandle_from_native(be32toh(pinctrl_data[0]));
100		pc = fdtbus_pinctrl_lookup(xref);
101		if (pc == NULL)
102			return ENXIO;
103
104		if (of_getprop_uint32(OF_parent(xref), "#pinctrl-cells", &pinctrl_cells) != 0)
105			pinctrl_cells = 1;
106
107		error = pc->pc_funcs->set_config(pc->pc_dev, pinctrl_data, pinctrl_cells * 4);
108		if (error != 0)
109			return error;
110
111		pinctrl_data += pinctrl_cells;
112		len -= (pinctrl_cells * 4);
113	}
114
115	return 0;
116}
117
118int
119fdtbus_pinctrl_set_config(int phandle, const char *cfgname)
120{
121	u_int index;
122	int err;
123
124	err = fdtbus_get_index(phandle, "pinctrl-names", cfgname, &index);
125	if (err != 0)
126		return ENOENT;
127
128	return fdtbus_pinctrl_set_config_index(phandle, index);
129}
130
131bool
132fdtbus_pinctrl_has_config(int phandle, const char *cfgname)
133{
134	u_int index;
135
136	return fdtbus_get_index(phandle, "pinctrl-names", cfgname, &index) == 0;
137}
138
139/*
140 * Helper routines for parsing put properties related to pinctrl bindings.
141 */
142
143/*
144 * Pin mux settings apply to sets of pins specified by one of 3
145 * sets of properties:
146 *
147 *	- "pins" + "function"
148 *	- "groups" + "function"
149 *	- "pinmux"
150 *
151 * Eactly one of those 3 combinations must be specified.
152 */
153
154const char *
155fdtbus_pinctrl_parse_function(int phandle)
156{
157	return fdtbus_get_string(phandle, "function");
158}
159
160const void *
161fdtbus_pinctrl_parse_pins(int phandle, int *pins_len)
162{
163	int len;
164
165	/*
166	 * The pinctrl bindings specify that entries in "pins"
167	 * may be integers or strings; this is determined by
168	 * the hardware-specific binding.
169	 */
170
171	len = OF_getproplen(phandle, "pins");
172	if (len > 0) {
173		return fdtbus_get_prop(phandle, "pins", pins_len);
174	}
175
176	return NULL;
177}
178
179const char *
180fdtbus_pinctrl_parse_groups(int phandle, int *groups_len)
181{
182	int len;
183
184	len = OF_getproplen(phandle, "groups");
185	if (len > 0) {
186		*groups_len = len;
187		return fdtbus_get_string(phandle, "groups");
188	}
189
190	return NULL;
191}
192
193const u_int *
194fdtbus_pinctrl_parse_pinmux(int phandle, int *pinmux_len)
195{
196	int len;
197
198	len = OF_getproplen(phandle, "pinmux");
199	if (len > 0) {
200		return fdtbus_get_prop(phandle, "pinmux", pinmux_len);
201	}
202
203	return NULL;
204}
205
206int
207fdtbus_pinctrl_parse_bias(int phandle, int *pull_strength)
208{
209	const char *bias_prop = NULL;
210	int bias = -1;
211
212	/*
213	 * bias-pull-{up,down,pin-default} properties have an optional
214	 * argument: the pull strength in Ohms.  (In practice, this is
215	 * sometimes a hardware-specific constant.)
216	 *
217	 * XXXJRT How to represent bias-pull-pin-default?
218	 */
219
220	if (of_hasprop(phandle, "bias-disable")) {
221		bias = 0;
222	} else if (of_hasprop(phandle, "bias-pull-up")) {
223		bias_prop = "bias-pull-up";
224		bias = GPIO_PIN_PULLUP;
225	} else if (of_hasprop(phandle, "bias-pull-down")) {
226		bias_prop = "bias-pull-down";
227		bias = GPIO_PIN_PULLDOWN;
228	}
229
230	if (pull_strength) {
231		*pull_strength = -1;
232		if (bias_prop) {
233			uint32_t val;
234			if (of_getprop_uint32(phandle, bias_prop, &val) == 0) {
235				*pull_strength = (int)val;
236			}
237		}
238	}
239
240	return bias;
241}
242
243int
244fdtbus_pinctrl_parse_drive(int phandle)
245{
246	int drive = -1;
247
248	if (of_hasprop(phandle, "drive-push-pull"))
249		drive = GPIO_PIN_PUSHPULL;
250	else if (of_hasprop(phandle, "drive-open-drain"))
251		drive = GPIO_PIN_OPENDRAIN;
252	else if (of_hasprop(phandle, "drive-open-source"))
253		drive = 0;
254
255	return drive;
256}
257
258int
259fdtbus_pinctrl_parse_drive_strength(int phandle)
260{
261	int val;
262
263	/*
264	 * drive-strength has as an argument the target strength
265	 * in mA.
266	 */
267
268	if (of_getprop_uint32(phandle, "drive-strength", &val) == 0)
269		return val;
270
271	return -1;
272}
273int fdtbus_pinctrl_parse_input_output(int phandle, int *output_value)
274{
275	int direction = -1;
276	int pinval = -1;
277
278	if (of_hasprop(phandle, "input-enable")) {
279		direction = GPIO_PIN_INPUT;
280	} else if (of_hasprop(phandle, "input-disable")) {
281		/*
282		 * XXXJRT How to represent this?  This is more than
283		 * just "don't set the direction" - it's an active
284		 * command that might involve disabling an input
285		 * buffer on the pin.
286		 */
287	}
288
289	if (of_hasprop(phandle, "output-enable")) {
290		if (direction == -1)
291			direction = 0;
292		direction |= GPIO_PIN_OUTPUT;
293	} else if (of_hasprop(phandle, "output-disable")) {
294		if (direction == -1)
295			direction = 0;
296		direction |= GPIO_PIN_TRISTATE;
297	}
298
299	if (of_hasprop(phandle, "output-low")) {
300		if (direction == -1)
301			direction = 0;
302		direction |= GPIO_PIN_OUTPUT;
303		pinval = GPIO_PIN_LOW;
304	} else if (of_hasprop(phandle, "output-high")) {
305		if (direction == -1)
306			direction = 0;
307		direction |= GPIO_PIN_OUTPUT;
308		pinval = GPIO_PIN_HIGH;
309	}
310
311	if (output_value)
312		*output_value = pinval;
313
314	/*
315	 * XXX input-schmitt-enable
316	 * XXX input-schmitt-disable
317	 */
318
319	if (direction != -1
320	    && (direction & (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT))
321			 == (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)) {
322		direction |= GPIO_PIN_INOUT;
323	}
324
325	return direction;
326}
327