/* SPDX-License-Identifier: GPL-2.0-only */ #include <console/console.h> #include <device/i2c_simple.h> #include <stdint.h> #include <string.h> #include "ec.h" #include "ec_commands.h" #if CONFIG(EC_GOOGLE_CHROMEEC_I2C_PROTO3) #define PROTO3_FRAMING_BYTES sizeof(uint32_t) /* Just use the LPC host packet size to size the buffer. */ #define PROTO3_MAX_PACKET_SIZE 268 struct proto3_i2c_buf { uint8_t framing_bytes[PROTO3_FRAMING_BYTES]; uint8_t data[PROTO3_MAX_PACKET_SIZE]; } __attribute__((aligned(sizeof(uint32_t)))); static struct proto3_i2c_buf req_buf; static struct proto3_i2c_buf resp_buf; enum { CMD_INDEX, RESP_INDEX, SEGS_PER_CMD, }; struct i2c_ec { int bus; struct i2c_msg segs[SEGS_PER_CMD]; }; static struct i2c_ec ec_dev = { .bus = CONFIG_EC_GOOGLE_CHROMEEC_I2C_BUS, .segs[CMD_INDEX] = { .flags = 0, .slave = CONFIG_EC_GOOGLE_CHROMEEC_I2C_CHIP, /* Framing byte to be transferred prior to request. */ .buf = &req_buf.framing_bytes[3], }, .segs[RESP_INDEX] = { .flags = I2C_M_RD, .slave = CONFIG_EC_GOOGLE_CHROMEEC_I2C_CHIP, /* return code and total length before full response. */ .buf = &resp_buf.framing_bytes[2], }, }; void *crosec_get_buffer(size_t size, int req) { struct proto3_i2c_buf *ib; if (size > PROTO3_MAX_PACKET_SIZE) { printk(BIOS_DEBUG, "Proto v3 buffer request too large: %zu!\n", size); return NULL; } if (req) ib = &req_buf; else ib = &resp_buf; return &ib->data[0]; } static int crosec_i2c_io(size_t req_size, size_t resp_size, void *context) { struct i2c_ec *ec = context; uint8_t ret_code; size_t resp_len; if (req_size > PROTO3_MAX_PACKET_SIZE || resp_size > PROTO3_MAX_PACKET_SIZE) return -1; /* Place the framing byte and set size accordingly. */ ec->segs[CMD_INDEX].len = req_size + 1; ec->segs[CMD_INDEX].buf[0] = EC_COMMAND_PROTOCOL_3; /* Return code and length returned prior to packet data. */ ec->segs[RESP_INDEX].len = resp_size + 2; if (i2c_transfer(ec->bus, ec->segs, ARRAY_SIZE(ec->segs)) != 0) { printk(BIOS_ERR, "%s: Cannot complete read from i2c-%d:%#x\n", __func__, ec->bus, ec->segs[0].slave); return -1; } ret_code = ec->segs[RESP_INDEX].buf[0]; resp_len = ec->segs[RESP_INDEX].buf[1]; if (ret_code != 0) { printk(BIOS_ERR, "EC command returned 0x%x\n", ret_code); return -1; } if (resp_len > resp_size) { printk(BIOS_ERR, "Response length mismatch %zu vs %zu\n", resp_len, resp_size); return -1; } return 0; } int google_chromeec_command(struct chromeec_command *cec_command) { return crosec_command_proto(cec_command, crosec_i2c_io, &ec_dev); } #else /* CONFIG_EC_GOOGLE_CHROMEEC_I2C_PROTO3 */ /* Command (host->device) format for I2C: * uint8_t version, cmd, len, data[len], checksum; * * Response (device->host) format for I2C: * uint8_t response, len, data[len], checksum; * * Note the location of checksum is different from LPC protocol. * * The length is 8 bit so maximum data size is 0xff. * Any I2C command should fit in 0xff + 4 bytes, and max response length * is 0xff + 3 bytes. */ #define MAX_I2C_DATA_SIZE (0xff) typedef struct { uint8_t version; uint8_t command; uint8_t length; uint8_t data[MAX_I2C_DATA_SIZE + 1]; } EcCommandI2c; typedef struct { uint8_t response; uint8_t length; uint8_t data[MAX_I2C_DATA_SIZE + 1]; } EcResponseI2c; static inline void i2c_dump(int bus, int chip, const uint8_t *data, size_t size) { #ifdef TRACE_CHROMEEC printk(BIOS_INFO, "i2c: bus=%d, chip=%#x, size=%d, data: ", bus, chip, size); while (size-- > 0) { printk(BIOS_INFO, "%02X ", *data++); } printk(BIOS_INFO, "\n"); #endif } static int ec_verify_checksum(const EcResponseI2c *resp) { size_t size = sizeof(*resp) - sizeof(resp->data) + resp->length; uint8_t calculated = google_chromeec_calc_checksum( (const uint8_t *)resp, size); uint8_t received = resp->data[resp->length]; if (calculated != received) { printk(BIOS_ERR, "%s: Unmatch (rx: %#02x, calc: %#02x)\n", __func__, received, calculated); return 0; } return 1; } static void ec_fill_checksum(EcCommandI2c *cmd) { size_t size = sizeof(*cmd) - sizeof(cmd->data) + cmd->length; cmd->data[cmd->length] = google_chromeec_calc_checksum( (const uint8_t *)cmd, size); } int google_chromeec_command(struct chromeec_command *cec_command) { EcCommandI2c cmd; EcResponseI2c resp; int bus = CONFIG_EC_GOOGLE_CHROMEEC_I2C_BUS; int chip = CONFIG_EC_GOOGLE_CHROMEEC_I2C_CHIP; size_t size_i2c_cmd = (sizeof(cmd) - sizeof(cmd.data) + cec_command->cmd_size_in + 1), size_i2c_resp = (sizeof(resp) - sizeof(resp.data) + cec_command->cmd_size_out + 1); if (cec_command->cmd_size_in > MAX_I2C_DATA_SIZE || cec_command->cmd_size_out > MAX_I2C_DATA_SIZE) { printk(BIOS_ERR, "%s: Command data size too large (%d,%d)\n", __func__, cec_command->cmd_size_in, cec_command->cmd_size_out); cec_command->cmd_code = EC_RES_INVALID_PARAM; return 1; } /* Construct command. */ cmd.version = EC_CMD_VERSION0 + cec_command->cmd_version; cmd.command = cec_command->cmd_code; cmd.length = cec_command->cmd_size_in; memcpy(cmd.data, cec_command->cmd_data_in, cmd.length); ec_fill_checksum(&cmd); /* Start I2C communication */ i2c_dump(bus, chip, (const uint8_t *)&cmd, size_i2c_cmd); if (i2c_write_raw(bus, chip, (uint8_t *)&cmd, size_i2c_cmd) != 0) { printk(BIOS_ERR, "%s: Cannot complete write to i2c-%d:%#x\n", __func__, bus, chip); cec_command->cmd_code = EC_RES_ERROR; return 1; } if (i2c_read_raw(bus, chip, (uint8_t *)&resp, size_i2c_resp) != 0) { printk(BIOS_ERR, "%s: Cannot complete read from i2c-%d:%#x\n", __func__, bus, chip); cec_command->cmd_code = EC_RES_ERROR; return 1; } /* Verify and return response */ cec_command->cmd_code = resp.response; if (resp.response != EC_RES_SUCCESS) { printk(BIOS_DEBUG, "%s: Received bad result code %d\n", __func__, (int)resp.response); return 1; } if (resp.length > cec_command->cmd_size_out) { printk(BIOS_ERR, "%s: Received len %#02x too large\n", __func__, (int)resp.length); cec_command->cmd_code = EC_RES_INVALID_RESPONSE; return 1; } if (!ec_verify_checksum(&resp)) { cec_command->cmd_code = EC_RES_INVALID_CHECKSUM; return 1; } cec_command->cmd_size_out = resp.length; memcpy(cec_command->cmd_data_out, resp.data, resp.length); return 0; } #endif /* CONFIG_EC_GOOGLE_CHROMEEC_I2C_PROTO3 */ enum host_event_code google_chromeec_get_event(void) { printk(BIOS_ERR, "%s: Not supported.\n", __func__); return EC_HOST_EVENT_NONE; }