--- /dev/null
+/*
+ * Chromium OS cros_ec driver - LPC interface
+ *
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * 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 <common.h>
+#include <command.h>
+#include <cros_ec.h>
+#include <asm/io.h>
+
+#ifdef DEBUG_TRACE
+#define debug_trace(fmt, b...) debug(fmt, ##b)
+#else
+#define debug_trace(fmt, b...)
+#endif
+
+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) > 1000) {
+ debug("%s: Timeout waiting for CROS_EC sync\n",
+ __func__);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+int cros_ec_lpc_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version,
+ const uint8_t *dout, int dout_len,
+ uint8_t **dinp, int din_len)
+{
+ 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_HOST_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_HOST_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;
+}
+
+/*
+ * 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.
+ */
+int cros_ec_lpc_check_version(struct cros_ec_dev *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;
+}
Code Review / kvmfornfv.git / blobdiff