1/*- 2 * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27/* 28 * Samsung Chromebook Embedded Controller (EC) 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD$"); 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/bus.h> 37#include <sys/kernel.h> 38#include <sys/module.h> 39#include <sys/malloc.h> 40#include <sys/rman.h> 41#include <sys/timeet.h> 42#include <sys/timetc.h> 43#include <sys/watchdog.h> 44#include <sys/gpio.h> 45 46#include <dev/ofw/openfirm.h> 47#include <dev/ofw/ofw_bus.h> 48#include <dev/ofw/ofw_bus_subr.h> 49 50#include <machine/bus.h> 51#include <machine/cpu.h> 52#include <machine/intr.h> 53 54#include <dev/spibus/spi.h> 55#include <dev/spibus/spibusvar.h> 56 57#include "spibus_if.h" 58#include "gpio_if.h" 59 60#include <arm/samsung/exynos/chrome_ec.h> 61 62struct ec_softc { 63 device_t dev; 64 device_t dev_gpio; 65}; 66 67struct ec_softc *ec_sc; 68 69#define EC_SPI_CS 200 70 71static int 72assert_cs(struct ec_softc *sc, int enable) 73{ 74 /* Get the GPIO device */ 75 sc->dev_gpio = devclass_get_device(devclass_find("gpio"), 0); 76 if (sc->dev_gpio == NULL) { 77 device_printf(sc->dev, "Error: failed to get the GPIO dev\n"); 78 return (1); 79 } 80 81 GPIO_PIN_SETFLAGS(sc->dev_gpio, EC_SPI_CS, GPIO_PIN_OUTPUT); 82 83 if (enable) { 84 GPIO_PIN_SET(sc->dev_gpio, EC_SPI_CS, GPIO_PIN_LOW); 85 } else { 86 GPIO_PIN_SET(sc->dev_gpio, EC_SPI_CS, GPIO_PIN_HIGH); 87 } 88 89 return (0); 90} 91 92static int 93ec_probe(device_t dev) 94{ 95 96 device_set_desc(dev, "Chromebook Embedded Controller"); 97 return (BUS_PROBE_DEFAULT); 98} 99 100static int 101fill_checksum(uint8_t *data_out, int len) 102{ 103 int res; 104 int i; 105 106 res = 0; 107 for (i = 0; i < len; i++) { 108 res += data_out[i]; 109 } 110 111 data_out[len] = (res & 0xff); 112 113 return (0); 114} 115 116int 117ec_command(uint8_t cmd, uint8_t *dout, uint8_t dout_len, 118 uint8_t *dinp, uint8_t dinp_len) 119{ 120 struct spi_command spi_cmd; 121 struct ec_softc *sc; 122 uint8_t *msg_dout; 123 uint8_t *msg_dinp; 124 int ret; 125 int i; 126 127 memset(&spi_cmd, 0, sizeof(spi_cmd)); 128 129 msg_dout = malloc(dout_len + 4, M_DEVBUF, M_NOWAIT | M_ZERO); 130 msg_dinp = malloc(dinp_len + 4, M_DEVBUF, M_NOWAIT | M_ZERO); 131 132 spi_cmd.tx_cmd = msg_dout; 133 spi_cmd.rx_cmd = msg_dinp; 134 135 if (ec_sc == NULL) 136 return (-1); 137 138 sc = ec_sc; 139 140 msg_dout[0] = EC_CMD_VERSION0; 141 msg_dout[1] = cmd; 142 msg_dout[2] = dout_len; 143 144 for (i = 0; i < dout_len; i++) { 145 msg_dout[i + 3] = dout[i]; 146 } 147 148 fill_checksum(msg_dout, dout_len + 3); 149 150 assert_cs(sc, 1); 151 spi_cmd.rx_cmd_sz = spi_cmd.tx_cmd_sz = dout_len + 4; 152 ret = SPIBUS_TRANSFER(device_get_parent(sc->dev), sc->dev, &spi_cmd); 153 154 /* Wait 0xec */ 155 for (i = 0; i < 1000; i++) { 156 DELAY(10); 157 msg_dout[0] = 0xff; 158 spi_cmd.rx_cmd_sz = spi_cmd.tx_cmd_sz = 1; 159 SPIBUS_TRANSFER(device_get_parent(sc->dev), sc->dev, &spi_cmd); 160 if (msg_dinp[0] == 0xec) 161 break; 162 } 163 164 /* Get the rest */ 165 for (i = 0; i < (dout_len + 4); i++) 166 msg_dout[i] = 0xff; 167 spi_cmd.rx_cmd_sz = spi_cmd.tx_cmd_sz = dout_len + 4 - 1; 168 ret = SPIBUS_TRANSFER(device_get_parent(sc->dev), sc->dev, &spi_cmd); 169 assert_cs(sc, 0); 170 171 if (ret != 0) { 172 device_printf(sc->dev, "spibus_transfer returned %d\n", ret); 173 free(msg_dout, M_DEVBUF); 174 free(msg_dinp, M_DEVBUF); 175 return (-1); 176 } 177 178 for (i = 0; i < dinp_len; i++) { 179 dinp[i] = msg_dinp[i + 2]; 180 } 181 182 free(msg_dout, M_DEVBUF); 183 free(msg_dinp, M_DEVBUF); 184 185 return (0); 186} 187 188static int 189ec_attach(device_t dev) 190{ 191 struct ec_softc *sc; 192 193 sc = device_get_softc(dev); 194 sc->dev = dev; 195 196 ec_sc = sc; 197 198 return (0); 199} 200 201static int 202ec_detach(device_t dev) 203{ 204 struct ec_softc *sc; 205 206 sc = device_get_softc(dev); 207 208 return (0); 209} 210 211static device_method_t ec_methods[] = { 212 DEVMETHOD(device_probe, ec_probe), 213 DEVMETHOD(device_attach, ec_attach), 214 DEVMETHOD(device_detach, ec_detach), 215 { 0, 0 } 216}; 217 218static driver_t ec_driver = { 219 "chrome_ec", 220 ec_methods, 221 sizeof(struct ec_softc), 222}; 223 224static devclass_t ec_devclass; 225 226DRIVER_MODULE(chrome_ec, spibus, ec_driver, ec_devclass, 0, 0); 227MODULE_VERSION(chrome_ec, 1); 228MODULE_DEPEND(chrome_ec, spibus, 1, 1, 1); 229