| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Chromium OS cros_ec driver - LPC interface |
| * |
| * Copyright (c) 2012 The Chromium OS Authors. |
| */ |
| |
| /* |
| * The Matrix Keyboard Protocol driver handles talking to the keyboard |
| * controller chip. Mostly this is for keyboard functions, but some other |
| * things have slipped in, so we provide generic services to talk to the |
| * KBC. |
| */ |
| |
| #include <dm.h> |
| #include <command.h> |
| #include <cros_ec.h> |
| #include <log.h> |
| #include <time.h> |
| #include <asm/io.h> |
| |
| #ifdef DEBUG_TRACE |
| #define debug_trace(fmt, b...) debug(fmt, ##b) |
| #else |
| #define debug_trace(fmt, b...) |
| #endif |
| |
| /* Timeout waiting for a flash erase command to complete */ |
| static const int CROS_EC_CMD_TIMEOUT_MS = 5000; |
| |
| static int wait_for_sync(struct cros_ec_dev *dev) |
| { |
| unsigned long start; |
| |
| start = get_timer(0); |
| while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) { |
| if (get_timer(start) > CROS_EC_CMD_TIMEOUT_MS) { |
| debug("%s: Timeout waiting for CROS_EC sync\n", |
| __func__); |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| int cros_ec_lpc_packet(struct udevice *udev, int out_bytes, int in_bytes) |
| { |
| struct cros_ec_dev *dev = dev_get_uclass_priv(udev); |
| uint8_t *d; |
| int i; |
| |
| if (out_bytes > EC_LPC_HOST_PACKET_SIZE) |
| return log_msg_ret("Cannot send that many bytes\n", -E2BIG); |
| |
| if (in_bytes > EC_LPC_HOST_PACKET_SIZE) |
| return log_msg_ret("Cannot receive that many bytes\n", -E2BIG); |
| |
| if (wait_for_sync(dev)) |
| return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT); |
| |
| /* Write data */ |
| for (i = 0, d = (uint8_t *)dev->dout; i < out_bytes; i++, d++) |
| outb(*d, EC_LPC_ADDR_HOST_PACKET + i); |
| |
| /* Start the command */ |
| outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD); |
| |
| if (wait_for_sync(dev)) |
| return log_msg_ret("Timeout waiting ready\n", -ETIMEDOUT); |
| |
| /* Read back args */ |
| for (i = 0, d = dev->din; i < in_bytes; i++, d++) |
| *d = inb(EC_LPC_ADDR_HOST_PACKET + i); |
| |
| return in_bytes; |
| } |
| |
| int cros_ec_lpc_command(struct udevice *udev, uint8_t cmd, int cmd_version, |
| const uint8_t *dout, int dout_len, |
| uint8_t **dinp, int din_len) |
| { |
| struct cros_ec_dev *dev = dev_get_uclass_priv(udev); |
| const int cmd_addr = EC_LPC_ADDR_HOST_CMD; |
| const int data_addr = EC_LPC_ADDR_HOST_DATA; |
| const int args_addr = EC_LPC_ADDR_HOST_ARGS; |
| const int param_addr = EC_LPC_ADDR_HOST_PARAM; |
| |
| struct ec_lpc_host_args args; |
| uint8_t *d; |
| int csum; |
| int i; |
| |
| if (dout_len > EC_PROTO2_MAX_PARAM_SIZE) { |
| debug("%s: Cannot send %d bytes\n", __func__, dout_len); |
| return -1; |
| } |
| |
| /* Fill in args */ |
| args.flags = EC_HOST_ARGS_FLAG_FROM_HOST; |
| args.command_version = cmd_version; |
| args.data_size = dout_len; |
| |
| /* Calculate checksum */ |
| csum = cmd + args.flags + args.command_version + args.data_size; |
| for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) |
| csum += *d; |
| |
| args.checksum = (uint8_t)csum; |
| |
| if (wait_for_sync(dev)) { |
| debug("%s: Timeout waiting ready\n", __func__); |
| return -1; |
| } |
| |
| /* Write args */ |
| for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++) |
| outb(*d, args_addr + i); |
| |
| /* Write data, if any */ |
| debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version); |
| for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) { |
| outb(*d, param_addr + i); |
| debug_trace("%02x ", *d); |
| } |
| |
| outb(cmd, cmd_addr); |
| debug_trace("\n"); |
| |
| if (wait_for_sync(dev)) { |
| debug("%s: Timeout waiting for response\n", __func__); |
| return -1; |
| } |
| |
| /* Check result */ |
| i = inb(data_addr); |
| if (i) { |
| debug("%s: CROS_EC result code %d\n", __func__, i); |
| return -i; |
| } |
| |
| /* Read back args */ |
| for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++) |
| *d = inb(args_addr + i); |
| |
| /* |
| * If EC didn't modify args flags, then somehow we sent a new-style |
| * command to an old EC, which means it would have read its params |
| * from the wrong place. |
| */ |
| if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) { |
| debug("%s: CROS_EC protocol mismatch\n", __func__); |
| return -EC_RES_INVALID_RESPONSE; |
| } |
| |
| if (args.data_size > din_len) { |
| debug("%s: CROS_EC returned too much data %d > %d\n", |
| __func__, args.data_size, din_len); |
| return -EC_RES_INVALID_RESPONSE; |
| } |
| |
| /* Read data, if any */ |
| for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) { |
| *d = inb(param_addr + i); |
| debug_trace("%02x ", *d); |
| } |
| debug_trace("\n"); |
| |
| /* Verify checksum */ |
| csum = cmd + args.flags + args.command_version + args.data_size; |
| for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) |
| csum += *d; |
| |
| if (args.checksum != (uint8_t)csum) { |
| debug("%s: CROS_EC response has invalid checksum\n", __func__); |
| return -EC_RES_INVALID_CHECKSUM; |
| } |
| *dinp = dev->din; |
| |
| /* Return actual amount of data received */ |
| return args.data_size; |
| } |
| |
| /** |
| * Initialize LPC protocol. |
| * |
| * @param dev CROS_EC device |
| * @param blob Device tree blob |
| * Return: 0 if ok, -1 on error |
| */ |
| int cros_ec_lpc_init(struct cros_ec_dev *dev, const void *blob) |
| { |
| int byte, i; |
| |
| /* See if we can find an EC at the other end */ |
| byte = 0xff; |
| byte &= inb(EC_LPC_ADDR_HOST_CMD); |
| byte &= inb(EC_LPC_ADDR_HOST_DATA); |
| for (i = 0; i < EC_PROTO2_MAX_PARAM_SIZE && (byte == 0xff); i++) |
| byte &= inb(EC_LPC_ADDR_HOST_PARAM + i); |
| if (byte == 0xff) { |
| debug("%s: CROS_EC device not found on LPC bus\n", |
| __func__); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* Return the byte of EC switch states */ |
| static int cros_ec_lpc_get_switches(struct udevice *dev) |
| { |
| return inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SWITCHES); |
| } |
| |
| /* |
| * Test if LPC command args are supported. |
| * |
| * The cheapest way to do this is by looking for the memory-mapped |
| * flag. This is faster than sending a new-style 'hello' command and |
| * seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag |
| * in args when it responds. |
| */ |
| static int cros_ec_lpc_check_version(struct udevice *dev) |
| { |
| if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' && |
| inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1) |
| == 'C' && |
| (inb(EC_LPC_ADDR_MEMMAP + |
| EC_MEMMAP_HOST_CMD_FLAGS) & |
| EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) { |
| return 0; |
| } |
| |
| printf("%s: ERROR: old EC interface not supported\n", __func__); |
| return -1; |
| } |
| |
| static int cros_ec_probe(struct udevice *dev) |
| { |
| return cros_ec_register(dev); |
| } |
| |
| static struct dm_cros_ec_ops cros_ec_ops = { |
| .packet = cros_ec_lpc_packet, |
| .command = cros_ec_lpc_command, |
| .check_version = cros_ec_lpc_check_version, |
| .get_switches = cros_ec_lpc_get_switches, |
| }; |
| |
| static const struct udevice_id cros_ec_ids[] = { |
| { .compatible = "google,cros-ec-lpc" }, |
| { } |
| }; |
| |
| U_BOOT_DRIVER(google_cros_ec_lpc) = { |
| .name = "google_cros_ec_lpc", |
| .id = UCLASS_CROS_EC, |
| .of_match = cros_ec_ids, |
| .probe = cros_ec_probe, |
| .ops = &cros_ec_ops, |
| }; |