178764a4eSHung-ying Tyan /* 278764a4eSHung-ying Tyan * Chromium OS cros_ec driver - I2C interface 378764a4eSHung-ying Tyan * 478764a4eSHung-ying Tyan * Copyright (c) 2012 The Chromium OS Authors. 578764a4eSHung-ying Tyan * 61a459660SWolfgang Denk * SPDX-License-Identifier: GPL-2.0+ 778764a4eSHung-ying Tyan */ 878764a4eSHung-ying Tyan 978764a4eSHung-ying Tyan /* 1078764a4eSHung-ying Tyan * The Matrix Keyboard Protocol driver handles talking to the keyboard 1178764a4eSHung-ying Tyan * controller chip. Mostly this is for keyboard functions, but some other 1278764a4eSHung-ying Tyan * things have slipped in, so we provide generic services to talk to the 1378764a4eSHung-ying Tyan * KBC. 1478764a4eSHung-ying Tyan */ 1578764a4eSHung-ying Tyan 1678764a4eSHung-ying Tyan #include <common.h> 1785df958cSSimon Glass #include <dm.h> 1878764a4eSHung-ying Tyan #include <i2c.h> 1978764a4eSHung-ying Tyan #include <cros_ec.h> 2078764a4eSHung-ying Tyan 2178764a4eSHung-ying Tyan #ifdef DEBUG_TRACE 2278764a4eSHung-ying Tyan #define debug_trace(fmt, b...) debug(fmt, #b) 2378764a4eSHung-ying Tyan #else 2478764a4eSHung-ying Tyan #define debug_trace(fmt, b...) 2578764a4eSHung-ying Tyan #endif 2678764a4eSHung-ying Tyan 27*147f785fSMoritz Fischer /** 28*147f785fSMoritz Fischer * Request format for protocol v3 29*147f785fSMoritz Fischer * byte 0 0xda (EC_COMMAND_PROTOCOL_3) 30*147f785fSMoritz Fischer * byte 1-8 struct ec_host_request 31*147f785fSMoritz Fischer * byte 10- response data 32*147f785fSMoritz Fischer */ 33*147f785fSMoritz Fischer struct ec_host_request_i2c { 34*147f785fSMoritz Fischer /* Always 0xda to backward compatible with v2 struct */ 35*147f785fSMoritz Fischer uint8_t command_protocol; 36*147f785fSMoritz Fischer struct ec_host_request ec_request; 37*147f785fSMoritz Fischer } __packed; 38*147f785fSMoritz Fischer 39*147f785fSMoritz Fischer /* 40*147f785fSMoritz Fischer * Response format for protocol v3 41*147f785fSMoritz Fischer * byte 0 result code 42*147f785fSMoritz Fischer * byte 1 packet_length 43*147f785fSMoritz Fischer * byte 2-9 struct ec_host_response 44*147f785fSMoritz Fischer * byte 10- response data 45*147f785fSMoritz Fischer */ 46*147f785fSMoritz Fischer struct ec_host_response_i2c { 47*147f785fSMoritz Fischer uint8_t result; 48*147f785fSMoritz Fischer uint8_t packet_length; 49*147f785fSMoritz Fischer struct ec_host_response ec_response; 50*147f785fSMoritz Fischer } __packed; 51*147f785fSMoritz Fischer 52*147f785fSMoritz Fischer static int cros_ec_i2c_packet(struct udevice *udev, int out_bytes, int in_bytes) 53*147f785fSMoritz Fischer { 54*147f785fSMoritz Fischer struct cros_ec_dev *dev = dev_get_uclass_priv(udev); 55*147f785fSMoritz Fischer struct dm_i2c_chip *chip = dev_get_parent_platdata(udev); 56*147f785fSMoritz Fischer struct ec_host_request_i2c *ec_request_i2c = 57*147f785fSMoritz Fischer (struct ec_host_request_i2c *)dev->dout; 58*147f785fSMoritz Fischer struct ec_host_response_i2c *ec_response_i2c = 59*147f785fSMoritz Fischer (struct ec_host_response_i2c *)dev->din; 60*147f785fSMoritz Fischer struct i2c_msg i2c_msg[2]; 61*147f785fSMoritz Fischer int ret; 62*147f785fSMoritz Fischer 63*147f785fSMoritz Fischer i2c_msg[0].addr = chip->chip_addr; 64*147f785fSMoritz Fischer i2c_msg[0].flags = 0; 65*147f785fSMoritz Fischer i2c_msg[1].addr = chip->chip_addr; 66*147f785fSMoritz Fischer i2c_msg[1].flags = I2C_M_RD; 67*147f785fSMoritz Fischer 68*147f785fSMoritz Fischer /* one extra byte, to indicate v3 */ 69*147f785fSMoritz Fischer i2c_msg[0].len = out_bytes + 1; 70*147f785fSMoritz Fischer i2c_msg[0].buf = dev->dout; 71*147f785fSMoritz Fischer 72*147f785fSMoritz Fischer /* stitch on EC_COMMAND_PROTOCOL_3 */ 73*147f785fSMoritz Fischer memmove(&ec_request_i2c->ec_request, dev->dout, out_bytes); 74*147f785fSMoritz Fischer ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3; 75*147f785fSMoritz Fischer 76*147f785fSMoritz Fischer /* two extra bytes for v3 */ 77*147f785fSMoritz Fischer i2c_msg[1].len = in_bytes + 2; 78*147f785fSMoritz Fischer i2c_msg[1].buf = dev->din; 79*147f785fSMoritz Fischer 80*147f785fSMoritz Fischer ret = dm_i2c_xfer(udev, &i2c_msg[0], 2); 81*147f785fSMoritz Fischer if (ret) { 82*147f785fSMoritz Fischer printf("%s: Could not execute transfer: %d\n", __func__, ret); 83*147f785fSMoritz Fischer return ret; 84*147f785fSMoritz Fischer } 85*147f785fSMoritz Fischer 86*147f785fSMoritz Fischer /* When we send a v3 request to v2 ec, ec won't recognize the 0xda 87*147f785fSMoritz Fischer * (EC_COMMAND_PROTOCOL_3) and will return with status 88*147f785fSMoritz Fischer * EC_RES_INVALID_COMMAND with zero data length 89*147f785fSMoritz Fischer * 90*147f785fSMoritz Fischer * In case of invalid command for v3 protocol the data length 91*147f785fSMoritz Fischer * will be at least sizeof(struct ec_host_response) 92*147f785fSMoritz Fischer */ 93*147f785fSMoritz Fischer if (ec_response_i2c->result == EC_RES_INVALID_COMMAND && 94*147f785fSMoritz Fischer ec_response_i2c->packet_length == 0) 95*147f785fSMoritz Fischer return -EPROTONOSUPPORT; 96*147f785fSMoritz Fischer 97*147f785fSMoritz Fischer if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) { 98*147f785fSMoritz Fischer printf("%s: response of %u bytes too short; not a full hdr\n", 99*147f785fSMoritz Fischer __func__, ec_response_i2c->packet_length); 100*147f785fSMoritz Fischer return -EBADMSG; 101*147f785fSMoritz Fischer } 102*147f785fSMoritz Fischer 103*147f785fSMoritz Fischer 104*147f785fSMoritz Fischer /* drop result and packet_len */ 105*147f785fSMoritz Fischer memmove(dev->din, &ec_response_i2c->ec_response, in_bytes); 106*147f785fSMoritz Fischer 107*147f785fSMoritz Fischer return in_bytes; 108*147f785fSMoritz Fischer } 109*147f785fSMoritz Fischer 11085df958cSSimon Glass static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd, 11185df958cSSimon Glass int cmd_version, const uint8_t *dout, 11285df958cSSimon Glass int dout_len, uint8_t **dinp, int din_len) 11378764a4eSHung-ying Tyan { 114e564f054SSimon Glass struct cros_ec_dev *dev = dev_get_uclass_priv(udev); 115e9b25f2eSMoritz Fischer struct dm_i2c_chip *chip = dev_get_parent_platdata(udev); 116e9b25f2eSMoritz Fischer struct i2c_msg i2c_msg[2]; 11778764a4eSHung-ying Tyan /* version8, cmd8, arglen8, out8[dout_len], csum8 */ 11878764a4eSHung-ying Tyan int out_bytes = dout_len + 4; 11978764a4eSHung-ying Tyan /* response8, arglen8, in8[din_len], checksum8 */ 12078764a4eSHung-ying Tyan int in_bytes = din_len + 3; 12178764a4eSHung-ying Tyan uint8_t *ptr; 12278764a4eSHung-ying Tyan /* Receive input data, so that args will be dword aligned */ 12378764a4eSHung-ying Tyan uint8_t *in_ptr; 124e8c12662SRandall Spangler int len, csum, ret; 12578764a4eSHung-ying Tyan 12678764a4eSHung-ying Tyan /* 12778764a4eSHung-ying Tyan * Sanity-check I/O sizes given transaction overhead in internal 12878764a4eSHung-ying Tyan * buffers. 12978764a4eSHung-ying Tyan */ 13078764a4eSHung-ying Tyan if (out_bytes > sizeof(dev->dout)) { 13178764a4eSHung-ying Tyan debug("%s: Cannot send %d bytes\n", __func__, dout_len); 13278764a4eSHung-ying Tyan return -1; 13378764a4eSHung-ying Tyan } 13478764a4eSHung-ying Tyan if (in_bytes > sizeof(dev->din)) { 13578764a4eSHung-ying Tyan debug("%s: Cannot receive %d bytes\n", __func__, din_len); 13678764a4eSHung-ying Tyan return -1; 13778764a4eSHung-ying Tyan } 13878764a4eSHung-ying Tyan assert(dout_len >= 0); 13978764a4eSHung-ying Tyan assert(dinp); 14078764a4eSHung-ying Tyan 141e9b25f2eSMoritz Fischer i2c_msg[0].addr = chip->chip_addr; 142e9b25f2eSMoritz Fischer i2c_msg[0].len = out_bytes; 143e9b25f2eSMoritz Fischer i2c_msg[0].buf = dev->dout; 144e9b25f2eSMoritz Fischer i2c_msg[0].flags = 0; 145e9b25f2eSMoritz Fischer 14678764a4eSHung-ying Tyan /* 14778764a4eSHung-ying Tyan * Copy command and data into output buffer so we can do a single I2C 14878764a4eSHung-ying Tyan * burst transaction. 14978764a4eSHung-ying Tyan */ 15078764a4eSHung-ying Tyan ptr = dev->dout; 15178764a4eSHung-ying Tyan 15278764a4eSHung-ying Tyan /* 15378764a4eSHung-ying Tyan * in_ptr starts of pointing to a dword-aligned input data buffer. 15478764a4eSHung-ying Tyan * We decrement it back by the number of header bytes we expect to 15578764a4eSHung-ying Tyan * receive, so that the first parameter of the resulting input data 15678764a4eSHung-ying Tyan * will be dword aligned. 15778764a4eSHung-ying Tyan */ 15878764a4eSHung-ying Tyan in_ptr = dev->din + sizeof(int64_t); 159e8c12662SRandall Spangler 160e8c12662SRandall Spangler if (dev->protocol_version != 2) { 161e8c12662SRandall Spangler /* Something we don't support */ 162e8c12662SRandall Spangler debug("%s: Protocol version %d unsupported\n", 163e8c12662SRandall Spangler __func__, dev->protocol_version); 164e8c12662SRandall Spangler return -1; 165e8c12662SRandall Spangler } 166e8c12662SRandall Spangler 16778764a4eSHung-ying Tyan *ptr++ = EC_CMD_VERSION0 + cmd_version; 16878764a4eSHung-ying Tyan *ptr++ = cmd; 16978764a4eSHung-ying Tyan *ptr++ = dout_len; 17078764a4eSHung-ying Tyan in_ptr -= 2; /* Expect status, length bytes */ 171e8c12662SRandall Spangler 17278764a4eSHung-ying Tyan memcpy(ptr, dout, dout_len); 17378764a4eSHung-ying Tyan ptr += dout_len; 17478764a4eSHung-ying Tyan 17578764a4eSHung-ying Tyan *ptr++ = (uint8_t) 17678764a4eSHung-ying Tyan cros_ec_calc_checksum(dev->dout, dout_len + 3); 17778764a4eSHung-ying Tyan 178e9b25f2eSMoritz Fischer i2c_msg[1].addr = chip->chip_addr; 179e9b25f2eSMoritz Fischer i2c_msg[1].len = in_bytes; 180e9b25f2eSMoritz Fischer i2c_msg[1].buf = in_ptr; 181e9b25f2eSMoritz Fischer i2c_msg[1].flags = I2C_M_RD; 182e9b25f2eSMoritz Fischer 18378764a4eSHung-ying Tyan /* Send output data */ 18478764a4eSHung-ying Tyan cros_ec_dump_data("out", -1, dev->dout, out_bytes); 185e9b25f2eSMoritz Fischer 186e9b25f2eSMoritz Fischer ret = dm_i2c_xfer(udev, &i2c_msg[0], 2); 18778764a4eSHung-ying Tyan if (ret) { 188e9b25f2eSMoritz Fischer debug("%s: Could not execute transfer to %s\n", __func__, 18985df958cSSimon Glass udev->name); 19078764a4eSHung-ying Tyan ret = -1; 19178764a4eSHung-ying Tyan } 19278764a4eSHung-ying Tyan 19378764a4eSHung-ying Tyan if (*in_ptr != EC_RES_SUCCESS) { 19478764a4eSHung-ying Tyan debug("%s: Received bad result code %d\n", __func__, *in_ptr); 19578764a4eSHung-ying Tyan return -(int)*in_ptr; 19678764a4eSHung-ying Tyan } 19778764a4eSHung-ying Tyan 19878764a4eSHung-ying Tyan len = in_ptr[1]; 19978764a4eSHung-ying Tyan if (len + 3 > sizeof(dev->din)) { 20078764a4eSHung-ying Tyan debug("%s: Received length %#02x too large\n", 20178764a4eSHung-ying Tyan __func__, len); 20278764a4eSHung-ying Tyan return -1; 20378764a4eSHung-ying Tyan } 20478764a4eSHung-ying Tyan csum = cros_ec_calc_checksum(in_ptr, 2 + len); 20578764a4eSHung-ying Tyan if (csum != in_ptr[2 + len]) { 20678764a4eSHung-ying Tyan debug("%s: Invalid checksum rx %#02x, calced %#02x\n", 20778764a4eSHung-ying Tyan __func__, in_ptr[2 + din_len], csum); 20878764a4eSHung-ying Tyan return -1; 20978764a4eSHung-ying Tyan } 21078764a4eSHung-ying Tyan din_len = min(din_len, len); 21178764a4eSHung-ying Tyan cros_ec_dump_data("in", -1, in_ptr, din_len + 3); 21278764a4eSHung-ying Tyan 21378764a4eSHung-ying Tyan /* Return pointer to dword-aligned input data, if any */ 21478764a4eSHung-ying Tyan *dinp = dev->din + sizeof(int64_t); 21578764a4eSHung-ying Tyan 21678764a4eSHung-ying Tyan return din_len; 21778764a4eSHung-ying Tyan } 21878764a4eSHung-ying Tyan 21985df958cSSimon Glass static int cros_ec_probe(struct udevice *dev) 22078764a4eSHung-ying Tyan { 22185df958cSSimon Glass return cros_ec_register(dev); 22278764a4eSHung-ying Tyan } 22378764a4eSHung-ying Tyan 22485df958cSSimon Glass static struct dm_cros_ec_ops cros_ec_ops = { 22585df958cSSimon Glass .command = cros_ec_i2c_command, 226*147f785fSMoritz Fischer .packet = cros_ec_i2c_packet, 22785df958cSSimon Glass }; 22878764a4eSHung-ying Tyan 22985df958cSSimon Glass static const struct udevice_id cros_ec_ids[] = { 2303fbb7871SSimon Glass { .compatible = "google,cros-ec-i2c" }, 23185df958cSSimon Glass { } 23285df958cSSimon Glass }; 23378764a4eSHung-ying Tyan 23485df958cSSimon Glass U_BOOT_DRIVER(cros_ec_i2c) = { 2353fbb7871SSimon Glass .name = "cros_ec_i2c", 23685df958cSSimon Glass .id = UCLASS_CROS_EC, 23785df958cSSimon Glass .of_match = cros_ec_ids, 23885df958cSSimon Glass .probe = cros_ec_probe, 23985df958cSSimon Glass .ops = &cros_ec_ops, 24085df958cSSimon Glass }; 241