2 * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPREC OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNEC FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINEC INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * Samsung Chromebook Embedded Controller
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/malloc.h>
41 #include <sys/timeet.h>
42 #include <sys/timetc.h>
43 #include <sys/watchdog.h>
46 #include <dev/ofw/openfirm.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
50 #include <machine/bus.h>
51 #include <machine/cpu.h>
52 #include <machine/intr.h>
54 #include <dev/iicbus/iiconf.h>
56 #include "iicbus_if.h"
59 #include <arm/samsung/exynos/chrome_ec.h>
68 struct ec_softc *ec_sc;
71 * bus_claim, bus_release
72 * both functions used for bus arbitration
73 * in multi-master mode
77 bus_claim(struct ec_softc *sc)
82 if (sc->our_gpio == 0 || sc->ec_gpio == 0) {
83 device_printf(sc->dev, "i2c arbitrator is not configured\n");
87 gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
88 if (gpio_dev == NULL) {
89 device_printf(sc->dev, "cant find gpio_dev\n");
93 /* Say we want the bus */
94 GPIO_PIN_SET(gpio_dev, sc->our_gpio, GPIO_PIN_LOW);
96 /* TODO: insert a delay to allow EC to react. */
98 /* Check EC decision */
99 GPIO_PIN_GET(gpio_dev, sc->ec_gpio, &status);
102 /* Okay. We have bus */
111 bus_release(struct ec_softc *sc)
115 if (sc->our_gpio == 0 || sc->ec_gpio == 0) {
116 device_printf(sc->dev, "i2c arbitrator is not configured\n");
120 gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
121 if (gpio_dev == NULL) {
122 device_printf(sc->dev, "cant find gpio_dev\n");
126 GPIO_PIN_SET(gpio_dev, sc->our_gpio, GPIO_PIN_HIGH);
132 ec_probe(device_t dev)
135 device_set_desc(dev, "Chromebook Embedded Controller");
136 return (BUS_PROBE_DEFAULT);
140 fill_checksum(uint8_t *data_out, int len)
146 for (i = 0; i < len; i++) {
150 data_out[len] = (res & 0xff);
156 ec_command(uint8_t cmd, uint8_t *dout, uint8_t dout_len,
157 uint8_t *dinp, uint8_t dinp_len)
165 msg_dout = malloc(dout_len + 4, M_DEVBUF, M_NOWAIT);
166 msg_dinp = malloc(dinp_len + 3, M_DEVBUF, M_NOWAIT);
173 msg_dout[0] = EC_CMD_VERSION0;
175 msg_dout[2] = dout_len;
177 for (i = 0; i < dout_len; i++) {
178 msg_dout[i + 3] = dout[i];
181 fill_checksum(msg_dout, dout_len + 3);
183 struct iic_msg msgs[] = {
184 { 0x1e, IIC_M_WR, dout_len + 4, msg_dout, },
185 { 0x1e, IIC_M_RD, dinp_len + 3, msg_dinp, },
188 ret = iicbus_transfer(sc->dev, msgs, 2);
190 device_printf(sc->dev, "i2c transfer returned %d\n", ret);
191 free(msg_dout, M_DEVBUF);
192 free(msg_dinp, M_DEVBUF);
196 for (i = 0; i < dinp_len; i++) {
197 dinp[i] = msg_dinp[i + 2];
200 free(msg_dout, M_DEVBUF);
201 free(msg_dinp, M_DEVBUF);
215 ec_command(EC_CMD_HELLO, data_in, 4,
222 configure_i2c_arbitrator(struct ec_softc *sc)
224 phandle_t arbitrator;
226 /* TODO: look for compatible entry instead of hard-coded path */
227 arbitrator = OF_finddevice("/i2c-arbitrator");
228 if (arbitrator != -1 &&
229 OF_hasprop(arbitrator, "freebsd,our-gpio") &&
230 OF_hasprop(arbitrator, "freebsd,ec-gpio")) {
231 sc->have_arbitrator = 1;
232 OF_getencprop(arbitrator, "freebsd,our-gpio",
233 &sc->our_gpio, sizeof(sc->our_gpio));
234 OF_getencprop(arbitrator, "freebsd,ec-gpio",
235 &sc->ec_gpio, sizeof(sc->ec_gpio));
237 sc->have_arbitrator = 0;
244 ec_attach(device_t dev)
248 sc = device_get_softc(dev);
253 configure_i2c_arbitrator(sc);
258 * We don't know cases when EC is master,
259 * so hold the bus forever for us.
263 if (sc->have_arbitrator && bus_claim(sc) != 0) {
271 ec_detach(device_t dev)
275 sc = device_get_softc(dev);
277 if (sc->have_arbitrator) {
284 static device_method_t ec_methods[] = {
285 DEVMETHOD(device_probe, ec_probe),
286 DEVMETHOD(device_attach, ec_attach),
287 DEVMETHOD(device_detach, ec_detach),
291 static driver_t ec_driver = {
294 sizeof(struct ec_softc),
297 static devclass_t ec_devclass;
299 DRIVER_MODULE(chrome_ec, iicbus, ec_driver, ec_devclass, 0, 0);
300 MODULE_VERSION(chrome_ec, 1);
301 MODULE_DEPEND(chrome_ec, iicbus, 1, 1, 1);