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/fdt/fdt_common.h>
47 #include <dev/ofw/openfirm.h>
48 #include <dev/ofw/ofw_bus.h>
49 #include <dev/ofw/ofw_bus_subr.h>
51 #include <machine/bus.h>
52 #include <machine/fdt.h>
53 #include <machine/cpu.h>
54 #include <machine/intr.h>
56 #include <dev/iicbus/iiconf.h>
58 #include "iicbus_if.h"
61 #include <arm/samsung/exynos/chrome_ec.h>
63 /* TODO: export to DTS */
71 struct ec_softc *ec_sc;
74 * bus_claim, bus_release
75 * both functions used for bus arbitration
76 * in multi-master mode
80 bus_claim(struct ec_softc *sc)
85 gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
86 if (gpio_dev == NULL) {
87 device_printf(sc->dev, "cant find gpio_dev\n");
91 /* Say we want the bus */
92 GPIO_PIN_SET(gpio_dev, OUR_GPIO, GPIO_PIN_LOW);
94 /* Check EC decision */
95 GPIO_PIN_GET(gpio_dev, EC_GPIO, &status);
98 /* Okay. We have bus */
107 bus_release(struct ec_softc *sc)
111 gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
112 if (gpio_dev == NULL) {
113 device_printf(sc->dev, "cant find gpio_dev\n");
117 GPIO_PIN_SET(gpio_dev, OUR_GPIO, GPIO_PIN_HIGH);
123 ec_probe(device_t dev)
126 device_set_desc(dev, "Chromebook Embedded Controller");
127 return (BUS_PROBE_DEFAULT);
131 fill_checksum(uint8_t *data_out, int len)
137 for (i = 0; i < len; i++) {
141 data_out[len] = (res & 0xff);
147 ec_command(uint8_t cmd, uint8_t *dout, uint8_t dout_len,
148 uint8_t *dinp, uint8_t dinp_len)
156 msg_dout = malloc(dout_len + 4, M_DEVBUF, M_NOWAIT);
157 msg_dinp = malloc(dinp_len + 4, M_DEVBUF, M_NOWAIT);
164 msg_dout[0] = EC_CMD_VERSION0;
166 msg_dout[2] = dout_len;
168 for (i = 0; i < dout_len; i++) {
169 msg_dout[i + 3] = dout[i];
172 fill_checksum(msg_dout, dout_len + 3);
174 struct iic_msg msgs[] = {
175 { 0x1e, IIC_M_WR, dout_len + 4, msg_dout, },
176 { 0x1e, IIC_M_RD, dinp_len + 4, msg_dinp, },
179 ret = iicbus_transfer(sc->dev, msgs, 2);
181 device_printf(sc->dev, "i2c transfer returned %d\n", ret);
182 free(msg_dout, M_DEVBUF);
183 free(msg_dinp, M_DEVBUF);
187 for (i = 0; i < dinp_len; i++) {
188 dinp[i] = msg_dinp[i + 3];
191 free(msg_dout, M_DEVBUF);
192 free(msg_dinp, M_DEVBUF);
206 ec_command(EC_CMD_MKBP_STATE, data_in, 4,
213 ec_attach(device_t dev)
217 sc = device_get_softc(dev);
225 * We don't know cases when EC is master,
226 * so hold the bus forever for us.
230 if (bus_claim(sc) != 0) {
238 ec_detach(device_t dev)
242 sc = device_get_softc(dev);
249 static device_method_t ec_methods[] = {
250 DEVMETHOD(device_probe, ec_probe),
251 DEVMETHOD(device_attach, ec_attach),
252 DEVMETHOD(device_detach, ec_detach),
256 static driver_t ec_driver = {
259 sizeof(struct ec_softc),
262 static devclass_t ec_devclass;
264 DRIVER_MODULE(chrome_ec, iicbus, ec_driver, ec_devclass, 0, 0);
265 MODULE_VERSION(chrome_ec, 1);
266 MODULE_DEPEND(chrome_ec, iicbus, 1, 1, 1);