1ae1f3df4SWarner Losh /*-
2f86e6000SWarner Losh * Copyright (c) 2015 M. Warner Losh <imp@FreeBSD.org>
3ae1f3df4SWarner Losh *
4ae1f3df4SWarner Losh * Redistribution and use in source and binary forms, with or without
5ae1f3df4SWarner Losh * modification, are permitted provided that the following conditions
6ae1f3df4SWarner Losh * are met:
7ae1f3df4SWarner Losh * 1. Redistributions of source code must retain the above copyright
8ae1f3df4SWarner Losh * notice, this list of conditions and the following disclaimer.
9ae1f3df4SWarner Losh * 2. Redistributions in binary form must reproduce the above copyright
10ae1f3df4SWarner Losh * notice, this list of conditions and the following disclaimer in the
11ae1f3df4SWarner Losh * documentation and/or other materials provided with the distribution.
12ae1f3df4SWarner Losh *
13ae1f3df4SWarner Losh * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14ae1f3df4SWarner Losh * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15ae1f3df4SWarner Losh * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16ae1f3df4SWarner Losh * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17ae1f3df4SWarner Losh * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18ae1f3df4SWarner Losh * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19ae1f3df4SWarner Losh * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20ae1f3df4SWarner Losh * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21ae1f3df4SWarner Losh * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22ae1f3df4SWarner Losh * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23ae1f3df4SWarner Losh * SUCH DAMAGE.
24ae1f3df4SWarner Losh */
25ae1f3df4SWarner Losh
26ae1f3df4SWarner Losh #include <sys/cdefs.h>
27ae1f3df4SWarner Losh #include "opt_platform.h"
28ae1f3df4SWarner Losh
29ae1f3df4SWarner Losh #include <sys/param.h>
30ae1f3df4SWarner Losh #include <sys/systm.h>
31ae1f3df4SWarner Losh #include <sys/bus.h>
32ae1f3df4SWarner Losh #include <sys/gpio.h>
33ae1f3df4SWarner Losh #include <sys/kernel.h>
34ae1f3df4SWarner Losh #include <sys/lock.h>
35ae1f3df4SWarner Losh #include <sys/malloc.h>
36ae1f3df4SWarner Losh #include <sys/module.h>
37ae1f3df4SWarner Losh #include <sys/mutex.h>
38ae1f3df4SWarner Losh
39c7b0edf2SIan Lepore #include <dev/gpio/gpiobusvar.h>
40c7b0edf2SIan Lepore #include <dev/ow/owll.h>
41c7b0edf2SIan Lepore
42ae1f3df4SWarner Losh #ifdef FDT
43ae1f3df4SWarner Losh #include <dev/ofw/ofw_bus.h>
44ae1f3df4SWarner Losh #include <dev/ofw/ofw_bus_subr.h>
45ae1f3df4SWarner Losh
46c7b0edf2SIan Lepore static struct ofw_compat_data compat_data[] = {
47c7b0edf2SIan Lepore {"w1-gpio", true},
48c7b0edf2SIan Lepore {NULL, false}
49c7b0edf2SIan Lepore };
50519b64e2SMark Johnston OFWBUS_PNP_INFO(compat_data);
51519b64e2SMark Johnston SIMPLEBUS_PNP_INFO(compat_data);
52c7b0edf2SIan Lepore #endif /* FDT */
53ae1f3df4SWarner Losh
54ae1f3df4SWarner Losh #define OW_PIN 0
55ae1f3df4SWarner Losh
56ae1f3df4SWarner Losh #define OWC_GPIOBUS_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
57ae1f3df4SWarner Losh #define OWC_GPIOBUS_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
58ae1f3df4SWarner Losh #define OWC_GPIOBUS_LOCK_INIT(_sc) \
59ae1f3df4SWarner Losh mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
60ae1f3df4SWarner Losh "owc_gpiobus", MTX_DEF)
61ae1f3df4SWarner Losh #define OWC_GPIOBUS_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);
62ae1f3df4SWarner Losh
63ae1f3df4SWarner Losh struct owc_gpiobus_softc
64ae1f3df4SWarner Losh {
65ae1f3df4SWarner Losh device_t sc_dev;
66c7b0edf2SIan Lepore gpio_pin_t sc_pin;
67ae1f3df4SWarner Losh struct mtx sc_mtx;
68ae1f3df4SWarner Losh };
69ae1f3df4SWarner Losh
70ae1f3df4SWarner Losh static int owc_gpiobus_probe(device_t);
71ae1f3df4SWarner Losh static int owc_gpiobus_attach(device_t);
72ae1f3df4SWarner Losh static int owc_gpiobus_detach(device_t);
73ae1f3df4SWarner Losh
74ae1f3df4SWarner Losh static int
owc_gpiobus_probe(device_t dev)75ae1f3df4SWarner Losh owc_gpiobus_probe(device_t dev)
76ae1f3df4SWarner Losh {
77c7b0edf2SIan Lepore int rv;
78c7b0edf2SIan Lepore
79c7b0edf2SIan Lepore /*
80c7b0edf2SIan Lepore * By default we only bid to attach if specifically added by our parent
81c7b0edf2SIan Lepore * (usually via hint.owc_gpiobus.#.at=busname). On FDT systems we bid
82c7b0edf2SIan Lepore * as the default driver based on being configured in the FDT data.
83c7b0edf2SIan Lepore */
84c7b0edf2SIan Lepore rv = BUS_PROBE_NOWILDCARD;
85c7b0edf2SIan Lepore
86ae1f3df4SWarner Losh #ifdef FDT
87c7b0edf2SIan Lepore if (ofw_bus_status_okay(dev) &&
88c7b0edf2SIan Lepore ofw_bus_search_compatible(dev, compat_data)->ocd_data)
89c7b0edf2SIan Lepore rv = BUS_PROBE_DEFAULT;
90ae1f3df4SWarner Losh #endif
91c7b0edf2SIan Lepore
92c7b0edf2SIan Lepore device_set_desc(dev, "GPIO one-wire bus");
93c7b0edf2SIan Lepore
94c7b0edf2SIan Lepore return (rv);
95ae1f3df4SWarner Losh }
96ae1f3df4SWarner Losh
97ae1f3df4SWarner Losh static int
owc_gpiobus_attach(device_t dev)98ae1f3df4SWarner Losh owc_gpiobus_attach(device_t dev)
99ae1f3df4SWarner Losh {
100ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
101c7b0edf2SIan Lepore int err;
102ae1f3df4SWarner Losh
103ae1f3df4SWarner Losh sc = device_get_softc(dev);
104ae1f3df4SWarner Losh sc->sc_dev = dev;
105c7b0edf2SIan Lepore
106c7b0edf2SIan Lepore #ifdef FDT
107c7b0edf2SIan Lepore /* Try to configure our pin from fdt data on fdt-based systems. */
108c7b0edf2SIan Lepore err = gpio_pin_get_by_ofw_idx(dev, ofw_bus_get_node(dev), OW_PIN,
109c7b0edf2SIan Lepore &sc->sc_pin);
110c7b0edf2SIan Lepore #else
111c7b0edf2SIan Lepore err = ENOENT;
112c7b0edf2SIan Lepore #endif
113c7b0edf2SIan Lepore /*
114c7b0edf2SIan Lepore * If we didn't get configured by fdt data and our parent is gpiobus,
115c7b0edf2SIan Lepore * see if we can be configured by the bus (allows hinted attachment even
116c7b0edf2SIan Lepore * on fdt-based systems).
117c7b0edf2SIan Lepore */
118c7b0edf2SIan Lepore if (err != 0 &&
119c7b0edf2SIan Lepore strcmp("gpiobus", device_get_name(device_get_parent(dev))) == 0)
120c7b0edf2SIan Lepore err = gpio_pin_get_by_child_index(dev, OW_PIN, &sc->sc_pin);
121c7b0edf2SIan Lepore
122c7b0edf2SIan Lepore /* If we didn't get configured by either method, whine and punt. */
123c7b0edf2SIan Lepore if (err != 0) {
124c7b0edf2SIan Lepore device_printf(sc->sc_dev,
125c7b0edf2SIan Lepore "cannot acquire gpio pin (config error)\n");
126c7b0edf2SIan Lepore return (err);
127c7b0edf2SIan Lepore }
128c7b0edf2SIan Lepore
129ae1f3df4SWarner Losh OWC_GPIOBUS_LOCK_INIT(sc);
130c7b0edf2SIan Lepore
131c7b0edf2SIan Lepore /*
132c7b0edf2SIan Lepore * Add the ow bus as a child, but defer probing and attaching it until
133c7b0edf2SIan Lepore * interrupts work, because we can't do IO for them until we can read
134c7b0edf2SIan Lepore * the system timecounter (which initializes after device attachments).
135c7b0edf2SIan Lepore */
136c7b0edf2SIan Lepore device_add_child(sc->sc_dev, "ow", -1);
1379f07ef76SWarner Losh return (bus_delayed_attach_children(dev));
138ae1f3df4SWarner Losh }
139ae1f3df4SWarner Losh
140ae1f3df4SWarner Losh static int
owc_gpiobus_detach(device_t dev)141ae1f3df4SWarner Losh owc_gpiobus_detach(device_t dev)
142ae1f3df4SWarner Losh {
143ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
144c7b0edf2SIan Lepore int err;
145ae1f3df4SWarner Losh
146ae1f3df4SWarner Losh sc = device_get_softc(dev);
147c7b0edf2SIan Lepore
148c7b0edf2SIan Lepore if ((err = device_delete_children(dev)) != 0)
149c7b0edf2SIan Lepore return (err);
150c7b0edf2SIan Lepore
151c7b0edf2SIan Lepore gpio_pin_release(sc->sc_pin);
152ae1f3df4SWarner Losh OWC_GPIOBUS_LOCK_DESTROY(sc);
153c7b0edf2SIan Lepore
154ae1f3df4SWarner Losh return (0);
155ae1f3df4SWarner Losh }
156ae1f3df4SWarner Losh
157ae1f3df4SWarner Losh /*
158ae1f3df4SWarner Losh * In the diagrams below, R is driven by the resistor pullup, M is driven by the
159ae1f3df4SWarner Losh * master, and S is driven by the slave / target.
160ae1f3df4SWarner Losh */
161ae1f3df4SWarner Losh
162ae1f3df4SWarner Losh /*
163ae1f3df4SWarner Losh * These macros let what why we're doing stuff shine in the code
164ae1f3df4SWarner Losh * below, and let the how be confined to here.
165ae1f3df4SWarner Losh */
166c7b0edf2SIan Lepore #define OUTPIN(sc) gpio_pin_setflags((sc)->sc_pin, GPIO_PIN_OUTPUT)
167c7b0edf2SIan Lepore #define INPIN(sc) gpio_pin_setflags((sc)->sc_pin, GPIO_PIN_INPUT)
168c7b0edf2SIan Lepore #define GETPIN(sc, bp) gpio_pin_is_active((sc)->sc_pin, (bp))
169c7b0edf2SIan Lepore #define LOW(sc) gpio_pin_set_active((sc)->sc_pin, false)
170ae1f3df4SWarner Losh
171ae1f3df4SWarner Losh /*
172ae1f3df4SWarner Losh * WRITE-ONE (see owll_if.m for timings) From Figure 4-1 AN-937
173ae1f3df4SWarner Losh *
174ae1f3df4SWarner Losh * |<---------tSLOT---->|<-tREC->|
175ae1f3df4SWarner Losh * High RRRRM | RRRRRRRRRRRR|RRRRRRRRM
176ae1f3df4SWarner Losh * M | R | | | M
177ae1f3df4SWarner Losh * M| R | | | M
178ae1f3df4SWarner Losh * Low MMMMMMM | | | MMMMMM...
179ae1f3df4SWarner Losh * |<-tLOW1->| | |
180ae1f3df4SWarner Losh * |<------15us--->| |
181ae1f3df4SWarner Losh * |<--------60us---->|
182ae1f3df4SWarner Losh */
183ae1f3df4SWarner Losh static int
owc_gpiobus_write_one(device_t dev,struct ow_timing * t)184ae1f3df4SWarner Losh owc_gpiobus_write_one(device_t dev, struct ow_timing *t)
185ae1f3df4SWarner Losh {
186ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
187ae1f3df4SWarner Losh
188ae1f3df4SWarner Losh sc = device_get_softc(dev);
189ae1f3df4SWarner Losh
190ae1f3df4SWarner Losh critical_enter();
191ae1f3df4SWarner Losh
192ae1f3df4SWarner Losh /* Force low */
193ae1f3df4SWarner Losh OUTPIN(sc);
194ae1f3df4SWarner Losh LOW(sc);
195ae1f3df4SWarner Losh DELAY(t->t_low1);
196ae1f3df4SWarner Losh
197ae1f3df4SWarner Losh /* Allow resistor to float line high */
198ae1f3df4SWarner Losh INPIN(sc);
199ae1f3df4SWarner Losh DELAY(t->t_slot - t->t_low1 + t->t_rec);
200ae1f3df4SWarner Losh
201ae1f3df4SWarner Losh critical_exit();
202ae1f3df4SWarner Losh
20301f1fff0SAndriy Gapon return (0);
204ae1f3df4SWarner Losh }
205ae1f3df4SWarner Losh
206ae1f3df4SWarner Losh /*
207ae1f3df4SWarner Losh * WRITE-ZERO (see owll_if.m for timings) From Figure 4-2 AN-937
208ae1f3df4SWarner Losh *
209ae1f3df4SWarner Losh * |<---------tSLOT------>|<-tREC->|
210ae1f3df4SWarner Losh * High RRRRM | | |RRRRRRRM
211ae1f3df4SWarner Losh * M | | R M
212ae1f3df4SWarner Losh * M| | | |R M
213ae1f3df4SWarner Losh * Low MMMMMMMMMMMMMMMMMMMMMR MMMMMM...
214ae1f3df4SWarner Losh * |<--15us->| | |
215ae1f3df4SWarner Losh * |<------60us--->| |
216ae1f3df4SWarner Losh * |<-------tLOW0------>|
217ae1f3df4SWarner Losh */
218ae1f3df4SWarner Losh static int
owc_gpiobus_write_zero(device_t dev,struct ow_timing * t)219ae1f3df4SWarner Losh owc_gpiobus_write_zero(device_t dev, struct ow_timing *t)
220ae1f3df4SWarner Losh {
221ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
222ae1f3df4SWarner Losh
223ae1f3df4SWarner Losh sc = device_get_softc(dev);
224ae1f3df4SWarner Losh
225ae1f3df4SWarner Losh critical_enter();
226ae1f3df4SWarner Losh
227ae1f3df4SWarner Losh /* Force low */
228ae1f3df4SWarner Losh OUTPIN(sc);
229ae1f3df4SWarner Losh LOW(sc);
230ae1f3df4SWarner Losh DELAY(t->t_low0);
231ae1f3df4SWarner Losh
232ae1f3df4SWarner Losh /* Allow resistor to float line high */
233ae1f3df4SWarner Losh INPIN(sc);
234ae1f3df4SWarner Losh DELAY(t->t_slot - t->t_low0 + t->t_rec);
235ae1f3df4SWarner Losh
236ae1f3df4SWarner Losh critical_exit();
237ae1f3df4SWarner Losh
23801f1fff0SAndriy Gapon return (0);
239ae1f3df4SWarner Losh }
240ae1f3df4SWarner Losh
241ae1f3df4SWarner Losh /*
242ae1f3df4SWarner Losh * READ-DATA (see owll_if.m for timings) From Figure 4-3 AN-937
243ae1f3df4SWarner Losh *
244ae1f3df4SWarner Losh * |<---------tSLOT------>|<-tREC->|
245ae1f3df4SWarner Losh * High RRRRM | rrrrrrrrrrrrrrrRRRRRRRM
246ae1f3df4SWarner Losh * M | r | R M
247ae1f3df4SWarner Losh * M| r | |R M
248ae1f3df4SWarner Losh * Low MMMMMMMSSSSSSSSSSSSSSR MMMMMM...
249ae1f3df4SWarner Losh * |<tLOWR>< sample > |
250ae1f3df4SWarner Losh * |<------tRDV---->| |
251ae1f3df4SWarner Losh * ->| |<-tRELEASE
252ae1f3df4SWarner Losh *
253ae1f3df4SWarner Losh * r -- allowed to pull high via the resitor when slave writes a 1-bit
254ae1f3df4SWarner Losh *
255ae1f3df4SWarner Losh */
256ae1f3df4SWarner Losh static int
owc_gpiobus_read_data(device_t dev,struct ow_timing * t,int * bit)257ae1f3df4SWarner Losh owc_gpiobus_read_data(device_t dev, struct ow_timing *t, int *bit)
258ae1f3df4SWarner Losh {
259ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
260c7b0edf2SIan Lepore bool sample;
261ae1f3df4SWarner Losh sbintime_t then, now;
262ae1f3df4SWarner Losh
263ae1f3df4SWarner Losh sc = device_get_softc(dev);
264ae1f3df4SWarner Losh
265c1750b82SAndriy Gapon critical_enter();
266c1750b82SAndriy Gapon
267ae1f3df4SWarner Losh /* Force low for t_lowr microseconds */
268ae1f3df4SWarner Losh then = sbinuptime();
269ae1f3df4SWarner Losh OUTPIN(sc);
270ae1f3df4SWarner Losh LOW(sc);
271ae1f3df4SWarner Losh DELAY(t->t_lowr);
272ae1f3df4SWarner Losh
273ae1f3df4SWarner Losh /*
274ae1f3df4SWarner Losh * Slave is supposed to hold the line low for t_rdv microseconds for 0
275ae1f3df4SWarner Losh * and immediately float it high for a 1. This is measured from the
276ae1f3df4SWarner Losh * master's pushing the line low.
277ae1f3df4SWarner Losh */
278ae1f3df4SWarner Losh INPIN(sc);
279ae1f3df4SWarner Losh do {
280ae1f3df4SWarner Losh now = sbinuptime();
281ae1f3df4SWarner Losh GETPIN(sc, &sample);
282c7b0edf2SIan Lepore } while (now - then < (t->t_rdv + 2) * SBT_1US && sample == false);
283ae1f3df4SWarner Losh critical_exit();
284ae1f3df4SWarner Losh
285bb7b803bSAndriy Gapon if (now - then < t->t_rdv * SBT_1US)
286ae1f3df4SWarner Losh *bit = 1;
287ae1f3df4SWarner Losh else
288ae1f3df4SWarner Losh *bit = 0;
289ae1f3df4SWarner Losh
290ae1f3df4SWarner Losh /* Wait out the rest of t_slot */
291ae1f3df4SWarner Losh do {
292ae1f3df4SWarner Losh now = sbinuptime();
293b8c776baSAndriy Gapon } while (now - then < (t->t_slot + t->t_rec) * SBT_1US);
294ae1f3df4SWarner Losh
295c7b0edf2SIan Lepore return (0);
296ae1f3df4SWarner Losh }
297ae1f3df4SWarner Losh
298ae1f3df4SWarner Losh /*
299ae1f3df4SWarner Losh * RESET AND PRESENCE PULSE (see owll_if.m for timings) From Figure 4-4 AN-937
300ae1f3df4SWarner Losh *
301ae1f3df4SWarner Losh * |<---------tRSTH------------>|
302ae1f3df4SWarner Losh * High RRRM | | RRRRRRRS | RRRR RRM
303ae1f3df4SWarner Losh * M | |R| |S | R M
304ae1f3df4SWarner Losh * M| R | | S |R M
305ae1f3df4SWarner Losh * Low MMMMMMMM MMMMMM| | | SSSSSSSSSS MMMMMM
306ae1f3df4SWarner Losh * |<----tRSTL--->| | |<-tPDL---->|
307ae1f3df4SWarner Losh * | ->| |<-tR | |
308ae1f3df4SWarner Losh * |<tPDH>|
309ae1f3df4SWarner Losh *
310ae1f3df4SWarner Losh * Note: for Regular Speed operations, tRSTL + tR should be less than 960us to
311c7b0edf2SIan Lepore * avoid interfering with other devices on the bus.
312c7b0edf2SIan Lepore *
313c7b0edf2SIan Lepore * Return values in *bit:
314c7b0edf2SIan Lepore * -1 = Bus wiring error (stuck low).
315c7b0edf2SIan Lepore * 0 = no presence pulse
316c7b0edf2SIan Lepore * 1 = presence pulse detected
317ae1f3df4SWarner Losh */
318ae1f3df4SWarner Losh static int
owc_gpiobus_reset_and_presence(device_t dev,struct ow_timing * t,int * bit)319ae1f3df4SWarner Losh owc_gpiobus_reset_and_presence(device_t dev, struct ow_timing *t, int *bit)
320ae1f3df4SWarner Losh {
321ae1f3df4SWarner Losh struct owc_gpiobus_softc *sc;
322c7b0edf2SIan Lepore bool sample;
323ae1f3df4SWarner Losh
324ae1f3df4SWarner Losh sc = device_get_softc(dev);
325ae1f3df4SWarner Losh
326ae1f3df4SWarner Losh /*
327ae1f3df4SWarner Losh * Read the current state of the bus. The steady state of an idle bus is
328ae1f3df4SWarner Losh * high. Badly wired buses that are missing the required pull up, or
329ae1f3df4SWarner Losh * that have a short circuit to ground cause all kinds of mischief when
330c7b0edf2SIan Lepore * we try to read them later. Return EIO if the bus is currently low.
331ae1f3df4SWarner Losh */
332ae1f3df4SWarner Losh INPIN(sc);
333c7b0edf2SIan Lepore GETPIN(sc, &sample);
334c7b0edf2SIan Lepore if (sample == false) {
335ae1f3df4SWarner Losh *bit = -1;
33601f1fff0SAndriy Gapon return (EIO);
337ae1f3df4SWarner Losh }
338ae1f3df4SWarner Losh
339ae1f3df4SWarner Losh critical_enter();
340ae1f3df4SWarner Losh
341ae1f3df4SWarner Losh /* Force low */
342ae1f3df4SWarner Losh OUTPIN(sc);
343ae1f3df4SWarner Losh LOW(sc);
344ae1f3df4SWarner Losh DELAY(t->t_rstl);
345ae1f3df4SWarner Losh
346ae1f3df4SWarner Losh /* Allow resistor to float line high and then wait for reset pulse */
347ae1f3df4SWarner Losh INPIN(sc);
348ae1f3df4SWarner Losh DELAY(t->t_pdh + t->t_pdl / 2);
349ae1f3df4SWarner Losh
350ae1f3df4SWarner Losh /* Read presence pulse */
351c7b0edf2SIan Lepore GETPIN(sc, &sample);
352c7b0edf2SIan Lepore *bit = sample;
353ae1f3df4SWarner Losh
354ae1f3df4SWarner Losh critical_exit();
355ae1f3df4SWarner Losh
356ae1f3df4SWarner Losh DELAY(t->t_rsth - (t->t_pdh + t->t_pdl / 2)); /* Timing not critical for this one */
357ae1f3df4SWarner Losh
358ae1f3df4SWarner Losh /*
359ae1f3df4SWarner Losh * Read the state of the bus after we've waited past the end of the rest
360ae1f3df4SWarner Losh * window. It should return to high. If it is low, then we have some
361ae1f3df4SWarner Losh * problem and should abort the reset.
362ae1f3df4SWarner Losh */
363c7b0edf2SIan Lepore GETPIN(sc, &sample);
364c7b0edf2SIan Lepore if (sample == false) {
365ae1f3df4SWarner Losh *bit = -1;
36601f1fff0SAndriy Gapon return (EIO);
367ae1f3df4SWarner Losh }
368ae1f3df4SWarner Losh
36901f1fff0SAndriy Gapon return (0);
370ae1f3df4SWarner Losh }
371ae1f3df4SWarner Losh
372ae1f3df4SWarner Losh static device_method_t owc_gpiobus_methods[] = {
373ae1f3df4SWarner Losh /* Device interface */
374ae1f3df4SWarner Losh DEVMETHOD(device_probe, owc_gpiobus_probe),
375ae1f3df4SWarner Losh DEVMETHOD(device_attach, owc_gpiobus_attach),
376ae1f3df4SWarner Losh DEVMETHOD(device_detach, owc_gpiobus_detach),
377ae1f3df4SWarner Losh
378ae1f3df4SWarner Losh DEVMETHOD(owll_write_one, owc_gpiobus_write_one),
379ae1f3df4SWarner Losh DEVMETHOD(owll_write_zero, owc_gpiobus_write_zero),
380ae1f3df4SWarner Losh DEVMETHOD(owll_read_data, owc_gpiobus_read_data),
381ae1f3df4SWarner Losh DEVMETHOD(owll_reset_and_presence, owc_gpiobus_reset_and_presence),
382ae1f3df4SWarner Losh { 0, 0 }
383ae1f3df4SWarner Losh };
384ae1f3df4SWarner Losh
385ae1f3df4SWarner Losh static driver_t owc_gpiobus_driver = {
386ae1f3df4SWarner Losh "owc",
387ae1f3df4SWarner Losh owc_gpiobus_methods,
388ae1f3df4SWarner Losh sizeof(struct owc_gpiobus_softc),
389ae1f3df4SWarner Losh };
390ae1f3df4SWarner Losh
391c7b0edf2SIan Lepore #ifdef FDT
392ffd39155SJohn Baldwin DRIVER_MODULE(owc_gpiobus, simplebus, owc_gpiobus_driver, 0, 0);
393c7b0edf2SIan Lepore #endif
394c7b0edf2SIan Lepore
395ffd39155SJohn Baldwin DRIVER_MODULE(owc_gpiobus, gpiobus, owc_gpiobus_driver, 0, 0);
396b66ed8eeSAndriy Gapon MODULE_DEPEND(owc_gpiobus, ow, 1, 1, 1);
397926c3367SAndriy Gapon MODULE_DEPEND(owc_gpiobus, gpiobus, 1, 1, 1);
398926c3367SAndriy Gapon MODULE_VERSION(owc_gpiobus, 1);
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