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
43 struct 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
51 static LIST_HEAD(, fdtbus_pinctrl_controller) fdtbus_pinctrl_controllers =
52 LIST_HEAD_INITIALIZER(fdtbus_pinctrl_controllers);
53
54 int
fdtbus_register_pinctrl_config(device_t dev,int phandle,const struct fdtbus_pinctrl_controller_func * funcs)55 fdtbus_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
70 static struct fdtbus_pinctrl_controller *
fdtbus_pinctrl_lookup(int phandle)71 fdtbus_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
83 int
fdtbus_pinctrl_set_config_index(int phandle,u_int index)84 fdtbus_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
118 int
fdtbus_pinctrl_set_config(int phandle,const char * cfgname)119 fdtbus_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
131 bool
fdtbus_pinctrl_has_config(int phandle,const char * cfgname)132 fdtbus_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
154 const char *
fdtbus_pinctrl_parse_function(int phandle)155 fdtbus_pinctrl_parse_function(int phandle)
156 {
157 return fdtbus_get_string(phandle, "function");
158 }
159
160 const void *
fdtbus_pinctrl_parse_pins(int phandle,int * pins_len)161 fdtbus_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
179 const char *
fdtbus_pinctrl_parse_groups(int phandle,int * groups_len)180 fdtbus_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
193 const u_int *
fdtbus_pinctrl_parse_pinmux(int phandle,int * pinmux_len)194 fdtbus_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
206 int
fdtbus_pinctrl_parse_bias(int phandle,int * pull_strength)207 fdtbus_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
243 int
fdtbus_pinctrl_parse_drive(int phandle)244 fdtbus_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
258 int
fdtbus_pinctrl_parse_drive_strength(int phandle)259 fdtbus_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 }
fdtbus_pinctrl_parse_input_output(int phandle,int * output_value)273 int 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