/src/u-boot/drivers/misc/cros_ec.c

Source
// SPDX-License-Identifier: GPL-2.0+
/*
 * Chromium OS cros_ec driver
 *
 * Copyright (c) 2012 The Chromium OS Authors.
 */

/*
 * This is the interface to the Chrome OS EC. It provides keyboard functions,
 * power control and battery management. Quite a few other functions are
 * provided to enable the EC software to be updated, talk to the EC's I2C bus
 * and store a small amount of data in a memory which persists while the EC
 * is not reset.
 */

#define LOG_CATEGORY UCLASS_CROS_EC

#include <command.h>
#include <dm.h>
#include <i2c.h>
#include <cros_ec.h>
#include <fdtdec.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <time.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm-generic/gpio.h>
#include <dm/device-internal.h>
#include <dm/of_extra.h>
#include <dm/uclass-internal.h>

#ifdef DEBUG_TRACE
#define debug_trace(fmt, b...)  debug(fmt, #b)
#else
#define debug_trace(fmt, b...)
#endif

enum {
  /* Timeout waiting for a flash erase command to complete */
  CROS_EC_CMD_TIMEOUT_MS  = 5000,
  /* Timeout waiting for a synchronous hash to be recomputed */
  CROS_EC_CMD_HASH_TIMEOUT_MS = 2000,

  /* Wait 10 ms between attempts to check if EC's hash is ready */
  CROS_EC_HASH_CHECK_DELAY_MS = 10,

};

#define INVALID_HCMD 0xFF

/*
 * Map UHEPI masks to non UHEPI commands in order to support old EC FW
 * which does not support UHEPI command.
 */
static const struct {
  u8 set_cmd;
  u8 clear_cmd;
  u8 get_cmd;
} event_map[] = {
  [EC_HOST_EVENT_MAIN] = {
    INVALID_HCMD, EC_CMD_HOST_EVENT_CLEAR,
    INVALID_HCMD,
  },
  [EC_HOST_EVENT_B] = {
    INVALID_HCMD, EC_CMD_HOST_EVENT_CLEAR_B,
    EC_CMD_HOST_EVENT_GET_B,
  },
  [EC_HOST_EVENT_SCI_MASK] = {
    EC_CMD_HOST_EVENT_SET_SCI_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_SCI_MASK,
  },
  [EC_HOST_EVENT_SMI_MASK] = {
    EC_CMD_HOST_EVENT_SET_SMI_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_SMI_MASK,
  },
  [EC_HOST_EVENT_ALWAYS_REPORT_MASK] = {
    INVALID_HCMD, INVALID_HCMD, INVALID_HCMD,
  },
  [EC_HOST_EVENT_ACTIVE_WAKE_MASK] = {
    EC_CMD_HOST_EVENT_SET_WAKE_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_WAKE_MASK,
  },
  [EC_HOST_EVENT_LAZY_WAKE_MASK_S0IX] = {
    EC_CMD_HOST_EVENT_SET_WAKE_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_WAKE_MASK,
  },
  [EC_HOST_EVENT_LAZY_WAKE_MASK_S3] = {
    EC_CMD_HOST_EVENT_SET_WAKE_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_WAKE_MASK,
  },
  [EC_HOST_EVENT_LAZY_WAKE_MASK_S5] = {
    EC_CMD_HOST_EVENT_SET_WAKE_MASK, INVALID_HCMD,
    EC_CMD_HOST_EVENT_GET_WAKE_MASK,
  },
};

void cros_ec_dump_data(const char *name, int cmd, const uint8_t *data, int len)
{
#ifdef DEBUG
  int i;

  printf("%s: ", name);
  if (cmd != -1)
    printf("cmd=%#x: ", cmd);
  for (i = 0; i < len; i++)
    printf("%02x ", data[i]);
  printf("\n");
#endif
}

/*
 * Calculate a simple 8-bit checksum of a data block
 *
 * @param data  Data block to checksum
 * @param size  Size of data block in bytes
 * Return: checksum value (0 to 255)
 */
int cros_ec_calc_checksum(const uint8_t *data, int size)
{
  int csum, i;

  for (i = csum = 0; i < size; i++)
    csum += data[i];
  return csum & 0xff;
}

/**
 * Create a request packet for protocol version 3.
 *
 * The packet is stored in the device's internal output buffer.
 *
 * @param dev   CROS-EC device
 * @param cmd   Command to send (EC_CMD_...)
 * @param cmd_version Version of command to send (EC_VER_...)
 * @param dout          Output data (may be NULL If dout_len=0)
 * @param dout_len      Size of output data in bytes
 * Return: packet size in bytes, or <0 if error.
 */
static int create_proto3_request(struct cros_ec_dev *cdev,
         int cmd, int cmd_version,
         const void *dout, int dout_len)
{
  struct ec_host_request *rq = (struct ec_host_request *)cdev->dout;
  int out_bytes = dout_len + sizeof(*rq);

  /* Fail if output size is too big */
  if (out_bytes > (int)sizeof(cdev->dout)) {
    debug("%s: Cannot send %d bytes\n", __func__, dout_len);
    return -EC_RES_REQUEST_TRUNCATED;
  }

  /* Fill in request packet */
  rq->struct_version = EC_HOST_REQUEST_VERSION;
  rq->checksum = 0;
  rq->command = cmd;
  rq->command_version = cmd_version;
  rq->reserved = 0;
  rq->data_len = dout_len;

  /* Copy data after header */
  memcpy(rq + 1, dout, dout_len);

  /* Write checksum field so the entire packet sums to 0 */
  rq->checksum = (uint8_t)(-cros_ec_calc_checksum(cdev->dout, out_bytes));

  cros_ec_dump_data("out", cmd, cdev->dout, out_bytes);

  /* Return size of request packet */
  return out_bytes;
}

/**
 * Prepare the device to receive a protocol version 3 response.
 *
 * @param dev   CROS-EC device
 * @param din_len       Maximum size of response in bytes
 * Return: maximum expected number of bytes in response, or <0 if error.
 */
static int prepare_proto3_response_buffer(struct cros_ec_dev *cdev, int din_len)
{
  int in_bytes = din_len + sizeof(struct ec_host_response);

  /* Fail if input size is too big */
  if (in_bytes > (int)sizeof(cdev->din)) {
    debug("%s: Cannot receive %d bytes\n", __func__, din_len);
    return -EC_RES_RESPONSE_TOO_BIG;
  }

  /* Return expected size of response packet */
  return in_bytes;
}

/**
 * Handle a protocol version 3 response packet.
 *
 * The packet must already be stored in the device's internal input buffer.
 *
 * @param dev   CROS-EC device
 * @param dinp          Returns pointer to response data
 * @param din_len       Maximum size of response in bytes
 * Return: number of bytes of response data, or <0 if error. Note that error
 * codes can be from errno.h or -ve EC_RES_INVALID_CHECKSUM values (and they
 * overlap!)
 */
static int handle_proto3_response(struct cros_ec_dev *dev,
          uint8_t **dinp, int din_len)
{
  struct ec_host_response *rs = (struct ec_host_response *)dev->din;
  int in_bytes;
  int csum;

  cros_ec_dump_data("in-header", -1, dev->din, sizeof(*rs));

  /* Check input data */
  if (rs->struct_version != EC_HOST_RESPONSE_VERSION) {
    debug("%s: EC response version mismatch\n", __func__);
    return -EC_RES_INVALID_RESPONSE;
  }

  if (rs->reserved) {
    debug("%s: EC response reserved != 0\n", __func__);
    return -EC_RES_INVALID_RESPONSE;
  }

  if (rs->data_len > din_len) {
    debug("%s: EC returned too much data\n", __func__);
    return -EC_RES_RESPONSE_TOO_BIG;
  }

  cros_ec_dump_data("in-data", -1, dev->din + sizeof(*rs), rs->data_len);

  /* Update in_bytes to actual data size */
  in_bytes = sizeof(*rs) + rs->data_len;

  /* Verify checksum */
  csum = cros_ec_calc_checksum(dev->din, in_bytes);
  if (csum) {
    debug("%s: EC response checksum invalid: 0x%02x\n", __func__,
          csum);
    return -EC_RES_INVALID_CHECKSUM;
  }

  /* Return error result, if any */
  if (rs->result)
    return -(int)rs->result;

  /* If we're still here, set response data pointer and return length */
  *dinp = (uint8_t *)(rs + 1);

  return rs->data_len;
}

static int send_command_proto3(struct cros_ec_dev *cdev,
             int cmd, int cmd_version,
             const void *dout, int dout_len,
             uint8_t **dinp, int din_len)
{
  struct dm_cros_ec_ops *ops;
  int out_bytes, in_bytes;
  int rv;

  /* Create request packet */
  out_bytes = create_proto3_request(cdev, cmd, cmd_version,
            dout, dout_len);
  if (out_bytes < 0)
    return out_bytes;

  /* Prepare response buffer */
  in_bytes = prepare_proto3_response_buffer(cdev, din_len);
  if (in_bytes < 0)
    return in_bytes;

  ops = dm_cros_ec_get_ops(cdev->dev);
  rv = ops->packet ? ops->packet(cdev->dev, out_bytes, in_bytes) :
      -ENOSYS;
  if (rv < 0)
    return rv;

  /* Process the response */
  return handle_proto3_response(cdev, dinp, din_len);
}

static int send_command(struct cros_ec_dev *dev, uint cmd, int cmd_version,
      const void *dout, int dout_len,
      uint8_t **dinp, int din_len)
{
  struct dm_cros_ec_ops *ops;
  int ret = -1;

  /* Handle protocol version 3 support */
  if (dev->protocol_version == 3) {
    return send_command_proto3(dev, cmd, cmd_version,
             dout, dout_len, dinp, din_len);
  }

  ops = dm_cros_ec_get_ops(dev->dev);
  ret = ops->command(dev->dev, cmd, cmd_version,
         (const uint8_t *)dout, dout_len, dinp, din_len);

  return ret;
}

/**
 * Send a command to the CROS-EC device and return the reply.
 *
 * The device's internal input/output buffers are used.
 *
 * @param dev   CROS-EC device
 * @param cmd   Command to send (EC_CMD_...)
 * @param cmd_version Version of command to send (EC_VER_...)
 * @param dout          Output data (may be NULL If dout_len=0)
 * @param dout_len      Size of output data in bytes
 * @param dinp          Response data (may be NULL If din_len=0).
 *      If not NULL, it will be updated to point to the data
 *      and will always be double word aligned (64-bits)
 * @param din_len       Maximum size of response in bytes
 * Return: number of bytes in response, or -ve on error
 */
static int ec_command_inptr(struct udevice *dev, uint cmd,
          int cmd_version, const void *dout, int dout_len,
          uint8_t **dinp, int din_len)
{
  struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);
  uint8_t *din = NULL;
  int len;

  len = send_command(cdev, cmd, cmd_version, dout, dout_len, &din,
         din_len);

  /* If the command doesn't complete, wait a while */
  if (len == -EC_RES_IN_PROGRESS) {
    struct ec_response_get_comms_status *resp = NULL;
    ulong start;

    /* Wait for command to complete */
    start = get_timer(0);
    do {
      int ret;

      mdelay(50); /* Insert some reasonable delay */
      ret = send_command(cdev, EC_CMD_GET_COMMS_STATUS, 0,
             NULL, 0,
             (uint8_t **)&resp, sizeof(*resp));
      if (ret < 0)
        return ret;

      if (get_timer(start) > CROS_EC_CMD_TIMEOUT_MS) {
        debug("%s: Command %#02x timeout\n",
              __func__, cmd);
        return -EC_RES_TIMEOUT;
      }
    } while (resp->flags & EC_COMMS_STATUS_PROCESSING);

    /* OK it completed, so read the status response */
    /* not sure why it was 0 for the last argument */
    len = send_command(cdev, EC_CMD_RESEND_RESPONSE, 0, NULL, 0,
           &din, din_len);
  }

  debug("%s: len=%d, din=%p\n", __func__, len, din);
  if (dinp) {
    /* If we have any data to return, it must be 64bit-aligned */
    assert(len <= 0 || !((uintptr_t)din & 7));
    *dinp = din;
  }

  return len;
}

/**
 * Send a command to the CROS-EC device and return the reply.
 *
 * The device's internal input/output buffers are used.
 *
 * @param dev   CROS-EC device
 * @param cmd   Command to send (EC_CMD_...)
 * @param cmd_version Version of command to send (EC_VER_...)
 * @param dout          Output data (may be NULL If dout_len=0)
 * @param dout_len      Size of output data in bytes
 * @param din           Response data (may be NULL If din_len=0).
 *      It not NULL, it is a place for ec_command() to copy the
 *      data to.
 * @param din_len       Maximum size of response in bytes
 * Return: number of bytes in response, or -ve on error
 */
static int ec_command(struct udevice *dev, uint cmd, int cmd_version,
          const void *dout, int dout_len,
          void *din, int din_len)
{
  uint8_t *in_buffer;
  int len;

  assert((din_len == 0) || din);
  len = ec_command_inptr(dev, cmd, cmd_version, dout, dout_len,
             &in_buffer, din_len);
  if (len > 0) {
    /*
     * If we were asked to put it somewhere, do so, otherwise just
     * disregard the result.
     */
    if (din && in_buffer) {
      assert(len <= din_len);
      if (len > din_len)
        return -ENOSPC;
      memmove(din, in_buffer, len);
    }
  }
  return len;
}

int cros_ec_scan_keyboard(struct udevice *dev, struct mbkp_keyscan *scan)
{
  if (ec_command(dev, EC_CMD_MKBP_STATE, 0, NULL, 0, scan,
           sizeof(scan->data)) != sizeof(scan->data))
    return -1;

  return 0;
}

int cros_ec_get_next_event(struct udevice *dev,
         struct ec_response_get_next_event *event)
{
  int ret;

  ret = ec_command(dev, EC_CMD_GET_NEXT_EVENT, 0, NULL, 0,
       event, sizeof(*event));
  if (ret < 0)
    return ret;
  else if (ret != sizeof(*event))
    return -EC_RES_INVALID_RESPONSE;

  return 0;
}

int cros_ec_read_id(struct udevice *dev, char *id, int maxlen)
{
  struct ec_response_get_version *r;
  int ret;

  ret = ec_command_inptr(dev, EC_CMD_GET_VERSION, 0, NULL, 0,
             (uint8_t **)&r, sizeof(*r));
  if (ret != sizeof(*r)) {
    log_err("Got rc %d, expected %u\n", ret, (uint)sizeof(*r));
    return -1;
  }

  if (maxlen > (int)sizeof(r->version_string_ro))
    maxlen = sizeof(r->version_string_ro);

  switch (r->current_image) {
  case EC_IMAGE_RO:
    memcpy(id, r->version_string_ro, maxlen);
    break;
  case EC_IMAGE_RW:
    memcpy(id, r->version_string_rw, maxlen);
    break;
  default:
    log_err("Invalid EC image %d\n", r->current_image);
    return -1;
  }

  id[maxlen - 1] = '\0';
  return 0;
}

int cros_ec_read_version(struct udevice *dev,
       struct ec_response_get_version **versionp)
{
  if (ec_command_inptr(dev, EC_CMD_GET_VERSION, 0, NULL, 0,
      (uint8_t **)versionp, sizeof(**versionp))
      != sizeof(**versionp))
    return -1;

  return 0;
}

int cros_ec_read_build_info(struct udevice *dev, char **strp)
{
  if (ec_command_inptr(dev, EC_CMD_GET_BUILD_INFO, 0, NULL, 0,
      (uint8_t **)strp, EC_PROTO2_MAX_PARAM_SIZE) < 0)
    return -1;

  return 0;
}

int cros_ec_read_current_image(struct udevice *dev,
             enum ec_current_image *image)
{
  struct ec_response_get_version *r;

  if (ec_command_inptr(dev, EC_CMD_GET_VERSION, 0, NULL, 0,
      (uint8_t **)&r, sizeof(*r)) != sizeof(*r))
    return -1;

  *image = r->current_image;
  return 0;
}

static int cros_ec_wait_on_hash_done(struct udevice *dev,
             struct ec_params_vboot_hash *p,
             struct ec_response_vboot_hash *hash)
{
  ulong start;

  start = get_timer(0);
  while (hash->status == EC_VBOOT_HASH_STATUS_BUSY) {
    mdelay(CROS_EC_HASH_CHECK_DELAY_MS);

    p->cmd = EC_VBOOT_HASH_GET;

    if (ec_command(dev, EC_CMD_VBOOT_HASH, 0, p, sizeof(*p), hash,
             sizeof(*hash)) < 0)
      return -1;

    if (get_timer(start) > CROS_EC_CMD_HASH_TIMEOUT_MS) {
      debug("%s: EC_VBOOT_HASH_GET timeout\n", __func__);
      return -EC_RES_TIMEOUT;
    }
  }
  return 0;
}

int cros_ec_read_hash(struct udevice *dev, uint hash_offset,
          struct ec_response_vboot_hash *hash)
{
  struct ec_params_vboot_hash p;
  int rv;

  p.cmd = EC_VBOOT_HASH_GET;
  p.offset = hash_offset;
  if (ec_command(dev, EC_CMD_VBOOT_HASH, 0, &p, sizeof(p),
           hash, sizeof(*hash)) < 0)
    return -1;

  /* If the EC is busy calculating the hash, fidget until it's done. */
  rv = cros_ec_wait_on_hash_done(dev, &p, hash);
  if (rv)
    return rv;

  /* If the hash is valid, we're done. Otherwise, we have to kick it off
   * again and wait for it to complete. Note that we explicitly assume
   * that hashing zero bytes is always wrong, even though that would
   * produce a valid hash value. */
  if (hash->status == EC_VBOOT_HASH_STATUS_DONE && hash->size)
    return 0;

  debug("%s: No valid hash (status=%d size=%d). Compute one...\n",
        __func__, hash->status, hash->size);

  p.cmd = EC_VBOOT_HASH_START;
  p.hash_type = EC_VBOOT_HASH_TYPE_SHA256;
  p.nonce_size = 0;
  p.offset = hash_offset;

  if (ec_command(dev, EC_CMD_VBOOT_HASH, 0, &p, sizeof(p),
           hash, sizeof(*hash)) < 0)
    return -1;

  rv = cros_ec_wait_on_hash_done(dev, &p, hash);
  if (rv)
    return rv;
  if (hash->status != EC_VBOOT_HASH_STATUS_DONE) {
    log_err("Hash did not complete, status=%d\n", hash->status);
    return -EIO;
  }

  debug("%s: hash done\n", __func__);

  return 0;
}

static int cros_ec_invalidate_hash(struct udevice *dev)
{
  struct ec_params_vboot_hash p;
  struct ec_response_vboot_hash *hash;

  /* We don't have an explict command for the EC to discard its current
   * hash value, so we'll just tell it to calculate one that we know is
   * wrong (we claim that hashing zero bytes is always invalid).
   */
  p.cmd = EC_VBOOT_HASH_RECALC;
  p.hash_type = EC_VBOOT_HASH_TYPE_SHA256;
  p.nonce_size = 0;
  p.offset = 0;
  p.size = 0;

  debug("%s:\n", __func__);

  if (ec_command_inptr(dev, EC_CMD_VBOOT_HASH, 0, &p, sizeof(p),
           (uint8_t **)&hash, sizeof(*hash)) < 0)
    return -1;

  /* No need to wait for it to finish */
  return 0;
}

int cros_ec_hello(struct udevice *dev, uint *handshakep)
{
  struct ec_params_hello req;
  struct ec_response_hello *resp;

  req.in_data = 0x12345678;
  if (ec_command_inptr(dev, EC_CMD_HELLO, 0, &req, sizeof(req),
           (uint8_t **)&resp, sizeof(*resp)) < 0)
    return -EIO;
  if (resp->out_data != req.in_data + 0x01020304) {
    printf("Received invalid handshake %x\n", resp->out_data);
    if (handshakep)
      *handshakep = req.in_data;
    return -ENOTSYNC;
  }

  return 0;
}

int cros_ec_reboot(struct udevice *dev, enum ec_reboot_cmd cmd, uint8_t flags)
{
  struct ec_params_reboot_ec p;

  p.cmd = cmd;
  p.flags = flags;

  if (ec_command_inptr(dev, EC_CMD_REBOOT_EC, 0, &p, sizeof(p), NULL, 0)
      < 0)
    return -1;

  if (!(flags & EC_REBOOT_FLAG_ON_AP_SHUTDOWN)) {
    ulong start;

    /*
     * EC reboot will take place immediately so delay to allow it
     * to complete.  Note that some reboot types (EC_REBOOT_COLD)
     * will reboot the AP as well, in which case we won't actually
     * get to this point.
     */
    mdelay(50);
    start = get_timer(0);
    while (cros_ec_hello(dev, NULL)) {
      if (get_timer(start) > 3000) {
        log_err("EC did not return from reboot\n");
        return -ETIMEDOUT;
      }
      mdelay(5);
    }
  }

  return 0;
}

int cros_ec_interrupt_pending(struct udevice *dev)
{
  struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);

  /* no interrupt support : always poll */
  if (!dm_gpio_is_valid(&cdev->ec_int))
    return -ENOENT;

  return dm_gpio_get_value(&cdev->ec_int);
}

int cros_ec_info(struct udevice *dev, struct ec_response_mkbp_info *info)
{
  if (ec_command(dev, EC_CMD_MKBP_INFO, 0, NULL, 0, info,
           sizeof(*info)) != sizeof(*info))
    return -1;

  return 0;
}

int cros_ec_get_event_mask(struct udevice *dev, uint type, uint32_t *mask)
{
  struct ec_response_host_event_mask rsp;
  int ret;

  ret = ec_command(dev, type, 0, NULL, 0, &rsp, sizeof(rsp));
  if (ret < 0)
    return ret;
  else if (ret != sizeof(rsp))
    return -EINVAL;

  *mask = rsp.mask;

  return 0;
}

int cros_ec_set_event_mask(struct udevice *dev, uint type, uint32_t mask)
{
  struct ec_params_host_event_mask req;
  int ret;

  req.mask = mask;

  ret = ec_command(dev, type, 0, &req, sizeof(req), NULL, 0);
  if (ret < 0)
    return ret;

  return 0;
}

int cros_ec_get_host_events(struct udevice *dev, uint32_t *events_ptr)
{
  struct ec_response_host_event_mask *resp;

  /*
   * Use the B copy of the event flags, because the main copy is already
   * used by ACPI/SMI.
   */
  if (ec_command_inptr(dev, EC_CMD_HOST_EVENT_GET_B, 0, NULL, 0,
           (uint8_t **)&resp, sizeof(*resp)) < (int)sizeof(*resp))
    return -1;

  if (resp->mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INVALID))
    return -1;

  *events_ptr = resp->mask;
  return 0;
}

int cros_ec_clear_host_events(struct udevice *dev, uint32_t events)
{
  struct ec_params_host_event_mask params;

  params.mask = events;

  /*
   * Use the B copy of the event flags, so it affects the data returned
   * by cros_ec_get_host_events().
   */
  if (ec_command_inptr(dev, EC_CMD_HOST_EVENT_CLEAR_B, 0,
           &params, sizeof(params), NULL, 0) < 0)
    return -1;

  return 0;
}

int cros_ec_flash_protect(struct udevice *dev, uint32_t set_mask,
        uint32_t set_flags,
        struct ec_response_flash_protect *resp)
{
  struct ec_params_flash_protect params;

  params.mask = set_mask;
  params.flags = set_flags;

  if (ec_command(dev, EC_CMD_FLASH_PROTECT, EC_VER_FLASH_PROTECT,
           &params, sizeof(params),
           resp, sizeof(*resp)) != sizeof(*resp))
    return -1;

  return 0;
}

static int cros_ec_check_version(struct udevice *dev)
{
  struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);
  struct ec_params_hello req;

  struct dm_cros_ec_ops *ops;
  int ret;

  ops = dm_cros_ec_get_ops(dev);
  if (ops->check_version) {
    ret = ops->check_version(dev);
    if (ret)
      return ret;
  }

  /*
   * TODO(sjg@chromium.org).
   * There is a strange oddity here with the EC. We could just ignore
   * the response, i.e. pass the last two parameters as NULL and 0.
   * In this case we won't read back very many bytes from the EC.
   * On the I2C bus the EC gets upset about this and will try to send
   * the bytes anyway. This means that we will have to wait for that
   * to complete before continuing with a new EC command.
   *
   * This problem is probably unique to the I2C bus.
   *
   * So for now, just read all the data anyway.
   */

  /* Try sending a version 3 packet */
  cdev->protocol_version = 3;
  req.in_data = 0;
  ret = cros_ec_hello(dev, NULL);
  if (!ret || ret == -ENOTSYNC)
    return 0;

  /* Try sending a version 2 packet */
  cdev->protocol_version = 2;
  ret = cros_ec_hello(dev, NULL);
  if (!ret || ret == -ENOTSYNC)
    return 0;

  /*
   * Fail if we're still here, since the EC doesn't understand any
   * protcol version we speak.  Version 1 interface without command
   * version is no longer supported, and we don't know about any new
   * protocol versions.
   */
  cdev->protocol_version = 0;
  printf("%s: ERROR: old EC interface not supported\n", __func__);
  return -1;
}

int cros_ec_test(struct udevice *dev)
{
  uint out_data;
  int ret;

  ret = cros_ec_hello(dev, &out_data);
  if (ret == -ENOTSYNC) {
    printf("Received invalid handshake %x\n", out_data);
    return ret;
  } else if (ret) {
    printf("ec_command_inptr() returned error\n");
    return ret;
  }

  return 0;
}

int cros_ec_flash_offset(struct udevice *dev, enum ec_flash_region region,
          uint32_t *offset, uint32_t *size)
{
  struct ec_params_flash_region_info p;
  struct ec_response_flash_region_info *r;
  int ret;

  p.region = region;
  ret = ec_command_inptr(dev, EC_CMD_FLASH_REGION_INFO,
       EC_VER_FLASH_REGION_INFO,
       &p, sizeof(p), (uint8_t **)&r, sizeof(*r));
  if (ret != sizeof(*r))
    return -1;

  if (offset)
    *offset = r->offset;
  if (size)
    *size = r->size;

  return 0;
}

int cros_ec_flash_erase(struct udevice *dev, uint32_t offset, uint32_t size)
{
  struct ec_params_flash_erase p;

  p.offset = offset;
  p.size = size;
  return ec_command_inptr(dev, EC_CMD_FLASH_ERASE, 0, &p, sizeof(p),
      NULL, 0);
}

/**
 * Write a single block to the flash
 *
 * Write a block of data to the EC flash. The size must not exceed the flash
 * write block size which you can obtain from cros_ec_flash_write_burst_size().
 *
 * The offset starts at 0. You can obtain the region information from
 * cros_ec_flash_offset() to find out where to write for a particular region.
 *
 * Attempting to write to the region where the EC is currently running from
 * will result in an error.
 *
 * @param dev   CROS-EC device
 * @param data    Pointer to data buffer to write
 * @param offset  Offset within flash to write to.
 * @param size    Number of bytes to write
 * Return: 0 if ok, -1 on error
 */
static int cros_ec_flash_write_block(struct udevice *dev, const uint8_t *data,
             uint32_t offset, uint32_t size)
{
  struct ec_params_flash_write *p;
  int ret;

  p = malloc(sizeof(*p) + size);
  if (!p)
    return -ENOMEM;

  p->offset = offset;
  p->size = size;
  assert(data && p->size <= EC_FLASH_WRITE_VER0_SIZE);
  memcpy(p + 1, data, p->size);

  ret = ec_command_inptr(dev, EC_CMD_FLASH_WRITE, 0,
        p, sizeof(*p) + size, NULL, 0) >= 0 ? 0 : -1;

  free(p);

  return ret;
}

/**
 * Return optimal flash write burst size
 */
static int cros_ec_flash_write_burst_size(struct udevice *dev)
{
  return EC_FLASH_WRITE_VER0_SIZE;
}

/**
 * Check if a block of data is erased (all 0xff)
 *
 * This function is useful when dealing with flash, for checking whether a
 * data block is erased and thus does not need to be programmed.
 *
 * @param data    Pointer to data to check (must be word-aligned)
 * @param size    Number of bytes to check (must be word-aligned)
 * Return: 0 if erased, non-zero if any word is not erased
 */
static int cros_ec_data_is_erased(const uint32_t *data, int size)
{
  assert(!(size & 3));
  size /= sizeof(uint32_t);
  for (; size > 0; size -= 4, data++)
    if (*data != -1U)
      return 0;

  return 1;
}

/**
 * Read back flash parameters
 *
 * This function reads back parameters of the flash as reported by the EC
 *
 * @param dev  Pointer to device
 * @param info Pointer to output flash info struct
 */
int cros_ec_read_flashinfo(struct udevice *dev,
         struct ec_response_flash_info *info)
{
  int ret;

  ret = ec_command(dev, EC_CMD_FLASH_INFO, 0,
       NULL, 0, info, sizeof(*info));
  if (ret < 0)
    return ret;

  return ret < sizeof(*info) ? -1 : 0;
}

int cros_ec_flash_write(struct udevice *dev, const uint8_t *data,
      uint32_t offset, uint32_t size)
{
  struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);
  uint32_t burst = cros_ec_flash_write_burst_size(dev);
  uint32_t end, off;
  int ret;

  if (!burst)
    return -EINVAL;

  /*
   * TODO: round up to the nearest multiple of write size.  Can get away
   * without that on link right now because its write size is 4 bytes.
   */
  end = offset + size;
  for (off = offset; off < end; off += burst, data += burst) {
    uint32_t todo;

    /* If the data is empty, there is no point in programming it */
    todo = min(end - off, burst);
    if (cdev->optimise_flash_write &&
        cros_ec_data_is_erased((uint32_t *)data, todo))
      continue;

    ret = cros_ec_flash_write_block(dev, data, off, todo);
    if (ret)
      return ret;
  }

  return 0;
}

/**
 * Run verification on a slot
 *
 * @param me     CrosEc instance
 * @param region Region to run verification on
 * Return: 0 if success or not applicable. Non-zero if verification failed.
 */
int cros_ec_efs_verify(struct udevice *dev, enum ec_flash_region region)
{
  struct ec_params_efs_verify p;
  int rv;

  log_info("EFS: EC is verifying updated image...\n");
  p.region = region;

  rv = ec_command(dev, EC_CMD_EFS_VERIFY, 0, &p, sizeof(p), NULL, 0);
  if (rv >= 0) {
    log_info("EFS: Verification success\n");
    return 0;
  }
  if (rv == -EC_RES_INVALID_COMMAND) {
    log_info("EFS: EC doesn't support EFS_VERIFY command\n");
    return 0;
  }
  log_info("EFS: Verification failed\n");

  return rv;
}

/**
 * Read a single block from the flash
 *
 * Read a block of data from the EC flash. The size must not exceed the flash
 * write block size which you can obtain from cros_ec_flash_write_burst_size().
 *
 * The offset starts at 0. You can obtain the region information from
 * cros_ec_flash_offset() to find out where to read for a particular region.
 *
 * @param dev   CROS-EC device
 * @param data    Pointer to data buffer to read into
 * @param offset  Offset within flash to read from
 * @param size    Number of bytes to read
 * Return: 0 if ok, -1 on error
 */
static int cros_ec_flash_read_block(struct udevice *dev, uint8_t *data,
            uint32_t offset, uint32_t size)
{
  struct ec_params_flash_read p;

  p.offset = offset;
  p.size = size;

  return ec_command(dev, EC_CMD_FLASH_READ, 0,
        &p, sizeof(p), data, size) >= 0 ? 0 : -1;
}

int cros_ec_flash_read(struct udevice *dev, uint8_t *data, uint32_t offset,
           uint32_t size)
{
  uint32_t burst = cros_ec_flash_write_burst_size(dev);
  uint32_t end, off;
  int ret;

  end = offset + size;
  for (off = offset; off < end; off += burst, data += burst) {
    ret = cros_ec_flash_read_block(dev, data, off,
              min(end - off, burst));
    if (ret)
      return ret;
  }

  return 0;
}

int cros_ec_flash_update_rw(struct udevice *dev, const uint8_t *image,
          int image_size)
{
  uint32_t rw_offset, rw_size;
  int ret;

  if (cros_ec_flash_offset(dev, EC_FLASH_REGION_ACTIVE, &rw_offset,
    &rw_size))
    return -1;
  if (image_size > (int)rw_size)
    return -1;

  /* Invalidate the existing hash, just in case the AP reboots
   * unexpectedly during the update. If that happened, the EC RW firmware
   * would be invalid, but the EC would still have the original hash.
   */
  ret = cros_ec_invalidate_hash(dev);
  if (ret)
    return ret;

  /*
   * Erase the entire RW section, so that the EC doesn't see any garbage
   * past the new image if it's smaller than the current image.
   *
   * TODO: could optimize this to erase just the current image, since
   * presumably everything past that is 0xff's.  But would still need to
   * round up to the nearest multiple of erase size.
   */
  ret = cros_ec_flash_erase(dev, rw_offset, rw_size);
  if (ret)
    return ret;

  /* Write the image */
  ret = cros_ec_flash_write(dev, image, rw_offset, image_size);
  if (ret)
    return ret;

  return 0;
}

int cros_ec_get_sku_id(struct udevice *dev)
{
  struct ec_sku_id_info *r;
  int ret;

  ret = ec_command_inptr(dev, EC_CMD_GET_SKU_ID, 0, NULL, 0,
             (uint8_t **)&r, sizeof(*r));
  if (ret != sizeof(*r)) {
    if (ret >= 0)
      ret = -EIO;
    return ret;
  }

  return r->sku_id;
}

int cros_ec_read_nvdata(struct udevice *dev, uint8_t *block, int size)
{
  struct ec_params_vbnvcontext p;
  int len;

  if (size != EC_VBNV_BLOCK_SIZE && size != EC_VBNV_BLOCK_SIZE_V2)
    return -EINVAL;

  p.op = EC_VBNV_CONTEXT_OP_READ;

  len = ec_command(dev, EC_CMD_VBNV_CONTEXT, EC_VER_VBNV_CONTEXT,
       &p, sizeof(uint32_t) + size, block, size);
  if (len != size) {
    log_err("Expected %d bytes, got %d\n", size, len);
    return -EIO;
  }

  return 0;
}

int cros_ec_write_nvdata(struct udevice *dev, const uint8_t *block, int size)
{
  struct ec_params_vbnvcontext p;
  int len;

  if (size != EC_VBNV_BLOCK_SIZE && size != EC_VBNV_BLOCK_SIZE_V2)
    return -EINVAL;
  p.op = EC_VBNV_CONTEXT_OP_WRITE;
  memcpy(p.block, block, size);

  len = ec_command_inptr(dev, EC_CMD_VBNV_CONTEXT, EC_VER_VBNV_CONTEXT,
      &p, sizeof(uint32_t) + size, NULL, 0);
  if (len < 0)
    return -1;

  return 0;
}

int cros_ec_battery_cutoff(struct udevice *dev, uint8_t flags)
{
  struct ec_params_battery_cutoff p;
  int len;

  p.flags = flags;
  len = ec_command(dev, EC_CMD_BATTERY_CUT_OFF, 1, &p, sizeof(p),
       NULL, 0);

  if (len < 0)
    return -1;
  return 0;
}

int cros_ec_set_pwm_duty(struct udevice *dev, uint8_t index, uint16_t duty)
{
  struct ec_params_pwm_set_duty p;
  int ret;

  p.duty = duty;
  p.pwm_type = EC_PWM_TYPE_GENERIC;
  p.index = index;

  ret = ec_command(dev, EC_CMD_PWM_SET_DUTY, 0, &p, sizeof(p),
       NULL, 0);
  if (ret < 0)
    return ret;

  return 0;
}

int cros_ec_set_ldo(struct udevice *dev, uint8_t index, uint8_t state)
{
  struct ec_params_ldo_set params;

  params.index = index;
  params.state = state;

  if (ec_command_inptr(dev, EC_CMD_LDO_SET, 0, &params, sizeof(params),
           NULL, 0))
    return -1;

  return 0;
}

int cros_ec_get_ldo(struct udevice *dev, uint8_t index, uint8_t *state)
{
  struct ec_params_ldo_get params;
  struct ec_response_ldo_get *resp;

  params.index = index;

  if (ec_command_inptr(dev, EC_CMD_LDO_GET, 0, &params, sizeof(params),
           (uint8_t **)&resp, sizeof(*resp)) !=
           sizeof(*resp))
    return -1;

  *state = resp->state;

  return 0;
}

int cros_ec_register(struct udevice *dev)
{
  struct cros_ec_dev *cdev = dev_get_uclass_priv(dev);
  char id[MSG_BYTES];

  cdev->dev = dev;
  gpio_request_by_name(dev, "ec-interrupt", 0, &cdev->ec_int,
           GPIOD_IS_IN);
  cdev->optimise_flash_write = dev_read_bool(dev, "optimise-flash-write");

  if (cros_ec_check_version(dev)) {
    debug("%s: Could not detect CROS-EC version\n", __func__);
    return -CROS_EC_ERR_CHECK_VERSION;
  }

  if (cros_ec_read_id(dev, id, sizeof(id))) {
    debug("%s: Could not read KBC ID\n", __func__);
    return -CROS_EC_ERR_READ_ID;
  }

  /* Remember this device for use by the cros_ec command */
  debug("Google Chrome EC v%d CROS-EC driver ready, id '%s'\n",
        cdev->protocol_version, id);

  return 0;
}

int cros_ec_decode_ec_flash(struct udevice *dev, struct fdt_cros_ec *config)
{
  ofnode flash_node, node;

  flash_node = dev_read_subnode(dev, "flash");
  if (!ofnode_valid(flash_node)) {
    debug("Failed to find flash node\n");
    return -1;
  }

  if (ofnode_read_fmap_entry(flash_node,  &config->flash)) {
    debug("Failed to decode flash node in chrome-ec\n");
    return -1;
  }

  config->flash_erase_value = ofnode_read_s32_default(flash_node,
                  "erase-value", -1);
  ofnode_for_each_subnode(node, flash_node) {
    const char *name = ofnode_get_name(node);
    enum ec_flash_region region;

    if (0 == strcmp(name, "ro")) {
      region = EC_FLASH_REGION_RO;
    } else if (0 == strcmp(name, "rw")) {
      region = EC_FLASH_REGION_ACTIVE;
    } else if (0 == strcmp(name, "wp-ro")) {
      region = EC_FLASH_REGION_WP_RO;
    } else {
      debug("Unknown EC flash region name '%s'\n", name);
      return -1;
    }

    if (ofnode_read_fmap_entry(node, &config->region[region])) {
      debug("Failed to decode flash region in chrome-ec'\n");
      return -1;
    }
  }

  return 0;
}

int cros_ec_i2c_tunnel(struct udevice *dev, int port, struct i2c_msg *in,
           int nmsgs)
{
  union {
    struct ec_params_i2c_passthru p;
    uint8_t outbuf[EC_PROTO2_MAX_PARAM_SIZE];
  } params;
  union {
    struct ec_response_i2c_passthru r;
    uint8_t inbuf[EC_PROTO2_MAX_PARAM_SIZE];
  } response;
  struct ec_params_i2c_passthru *p = &params.p;
  struct ec_response_i2c_passthru *r = &response.r;
  struct ec_params_i2c_passthru_msg *msg;
  uint8_t *pdata, *read_ptr = NULL;
  int read_len;
  int size;
  int rv;
  int i;

  p->port = port;

  p->num_msgs = nmsgs;
  size = sizeof(*p) + p->num_msgs * sizeof(*msg);

  /* Create a message to write the register address and optional data */
  pdata = (uint8_t *)p + size;

  read_len = 0;
  for (i = 0, msg = p->msg; i < nmsgs; i++, msg++, in++) {
    bool is_read = in->flags & I2C_M_RD;

    msg->addr_flags = in->addr;
    msg->len = in->len;
    if (is_read) {
      msg->addr_flags |= EC_I2C_FLAG_READ;
      read_len += in->len;
      read_ptr = in->buf;
      if (sizeof(*r) + read_len > sizeof(response)) {
        puts("Read length too big for buffer\n");
        return -1;
      }
    } else {
      if (pdata - (uint8_t *)p + in->len > sizeof(params)) {
        puts("Params too large for buffer\n");
        return -1;
      }
      memcpy(pdata, in->buf, in->len);
      pdata += in->len;
    }
  }

  rv = ec_command(dev, EC_CMD_I2C_PASSTHRU, 0, p, pdata - (uint8_t *)p,
      r, sizeof(*r) + read_len);
  if (rv < 0)
    return rv;

  /* Parse response */
  if (r->i2c_status & EC_I2C_STATUS_ERROR) {
    printf("Transfer failed with status=0x%x\n", r->i2c_status);
    return -1;
  }

  if (rv < sizeof(*r) + read_len) {
    puts("Truncated read response\n");
    return -1;
  }

  /* We only support a single read message for each transfer */
  if (read_len)
    memcpy(read_ptr, r->data, read_len);

  return 0;
}

int cros_ec_get_features(struct udevice *dev, u64 *featuresp)
{
  struct ec_response_get_features r;
  int rv;

  rv = ec_command(dev, EC_CMD_GET_FEATURES, 0, NULL, 0, &r, sizeof(r));
  if (rv != sizeof(r))
    return -EIO;
  *featuresp = r.flags[0] | (u64)r.flags[1] << 32;

  return 0;
}

int cros_ec_check_feature(struct udevice *dev, uint feature)
{
  struct ec_response_get_features r;
  int rv;

  rv = ec_command(dev, EC_CMD_GET_FEATURES, 0, NULL, 0, &r, sizeof(r));
  if (rv != sizeof(r))
    return -EIO;

  if (feature >= 8 * sizeof(r.flags))
    return -EINVAL;

  return r.flags[feature / 32] & EC_FEATURE_MASK_0(feature) ? true :
     false;
}

/*
 * Query the EC for specified mask indicating enabled events.
 * The EC maintains separate event masks for SMI, SCI and WAKE.
 */
static int cros_ec_uhepi_cmd(struct udevice *dev, uint mask, uint action,
           uint64_t *value)
{
  int ret;
  struct ec_params_host_event req;
  struct ec_response_host_event rsp;

  req.action = action;
  req.mask_type = mask;
  if (action != EC_HOST_EVENT_GET)
    req.value = *value;
  else
    *value = 0;
  ret = ec_command(dev, EC_CMD_HOST_EVENT, 0, &req, sizeof(req), &rsp,
       sizeof(rsp));

  if (action != EC_HOST_EVENT_GET)
    return ret;
  if (ret == 0)
    *value = rsp.value;

  return ret;
}

static int cros_ec_handle_non_uhepi_cmd(struct udevice *dev, uint hcmd,
          uint action, uint64_t *value)
{
  int ret = -1;
  struct ec_params_host_event_mask req;
  struct ec_response_host_event_mask rsp;

  if (hcmd == INVALID_HCMD)
    return ret;

  if (action != EC_HOST_EVENT_GET)
    req.mask = (uint32_t)*value;
  else
    *value = 0;

  ret = ec_command(dev, hcmd, 0, &req, sizeof(req), &rsp, sizeof(rsp));
  if (action != EC_HOST_EVENT_GET)
    return ret;
  if (ret == 0)
    *value = rsp.mask;

  return ret;
}

bool cros_ec_is_uhepi_supported(struct udevice *dev)
{
#define UHEPI_SUPPORTED 1
#define UHEPI_NOT_SUPPORTED 2
  static int uhepi_support;

  if (!uhepi_support) {
    uhepi_support = cros_ec_check_feature(dev,
      EC_FEATURE_UNIFIED_WAKE_MASKS) > 0 ? UHEPI_SUPPORTED :
      UHEPI_NOT_SUPPORTED;
    log_debug("Chrome EC: UHEPI %s\n",
        uhepi_support == UHEPI_SUPPORTED ? "supported" :
        "not supported");
  }
  return uhepi_support == UHEPI_SUPPORTED;
}

static int cros_ec_get_mask(struct udevice *dev, uint type)
{
  u64 value = 0;

  if (cros_ec_is_uhepi_supported(dev)) {
    cros_ec_uhepi_cmd(dev, type, EC_HOST_EVENT_GET, &value);
  } else {
    assert(type < ARRAY_SIZE(event_map));
    cros_ec_handle_non_uhepi_cmd(dev, event_map[type].get_cmd,
               EC_HOST_EVENT_GET, &value);
  }
  return value;
}

static int cros_ec_clear_mask(struct udevice *dev, uint type, u64 mask)
{
  if (cros_ec_is_uhepi_supported(dev))
    return cros_ec_uhepi_cmd(dev, type, EC_HOST_EVENT_CLEAR, &mask);

  assert(type < ARRAY_SIZE(event_map));

  return cros_ec_handle_non_uhepi_cmd(dev, event_map[type].clear_cmd,
              EC_HOST_EVENT_CLEAR, &mask);
}

uint64_t cros_ec_get_events_b(struct udevice *dev)
{
  return cros_ec_get_mask(dev, EC_HOST_EVENT_B);
}

int cros_ec_clear_events_b(struct udevice *dev, uint64_t mask)
{
  log_debug("Chrome EC: clear events_b mask to 0x%016llx\n", mask);

  return cros_ec_clear_mask(dev, EC_HOST_EVENT_B, mask);
}

int cros_ec_read_limit_power(struct udevice *dev, int *limit_powerp)
{
  struct ec_params_charge_state p;
  struct ec_response_charge_state r;
  int ret;

  p.cmd = CHARGE_STATE_CMD_GET_PARAM;
  p.get_param.param = CS_PARAM_LIMIT_POWER;
  ret = ec_command(dev, EC_CMD_CHARGE_STATE, 0, &p, sizeof(p),
       &r, sizeof(r));

  /*
   * If our EC doesn't support the LIMIT_POWER parameter, assume that
   * LIMIT_POWER is not requested.
   */
  if (ret == -EC_RES_INVALID_PARAM || ret == -EC_RES_INVALID_COMMAND) {
    log_warning("PARAM_LIMIT_POWER not supported by EC\n");
    return -ENOSYS;
  }

  if (ret != sizeof(r.get_param))
    return -EINVAL;

  *limit_powerp = r.get_param.value;
  return 0;
}

int cros_ec_config_powerbtn(struct udevice *dev, uint32_t flags)
{
  struct ec_params_config_power_button params;
  int ret;

  params.flags = flags;
  ret = ec_command(dev, EC_CMD_CONFIG_POWER_BUTTON, 0,
       &params, sizeof(params), NULL, 0);
  if (ret < 0)
    return ret;

  return 0;
}

int cros_ec_get_lid_shutdown_mask(struct udevice *dev)
{
  u32 mask;
  int ret;

  ret = cros_ec_get_event_mask(dev, EC_CMD_HOST_EVENT_GET_SMI_MASK,
             &mask);
  if (ret < 0)
    return ret;

  return !!(mask & EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED));
}

int cros_ec_set_lid_shutdown_mask(struct udevice *dev, int enable)
{
  u32 mask;
  int ret;

  ret = cros_ec_get_event_mask(dev, EC_CMD_HOST_EVENT_GET_SMI_MASK,
             &mask);
  if (ret < 0)
    return ret;

  /* Set lid close event state in the EC SMI event mask */
  if (enable)
    mask |= EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED);
  else
    mask &= ~EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED);

  ret = cros_ec_set_event_mask(dev, EC_CMD_HOST_EVENT_SET_SMI_MASK, mask);
  if (ret < 0)
    return ret;

  printf("EC: %sabled lid close event\n", enable ? "en" : "dis");
  return 0;
}

int cros_ec_vstore_supported(struct udevice *dev)
{
  return cros_ec_check_feature(dev, EC_FEATURE_VSTORE);
}

int cros_ec_vstore_info(struct udevice *dev, u32 *lockedp)
{
  struct ec_response_vstore_info *resp;

  if (ec_command_inptr(dev, EC_CMD_VSTORE_INFO, 0, NULL, 0,
           (uint8_t **)&resp, sizeof(*resp)) != sizeof(*resp))
    return -EIO;

  if (lockedp)
    *lockedp = resp->slot_locked;

  return resp->slot_count;
}

/*
 * cros_ec_vstore_read - Read data from EC vstore slot
 *
 * @slot: vstore slot to read from
 * @data: buffer to store read data, must be EC_VSTORE_SLOT_SIZE bytes
 */
int cros_ec_vstore_read(struct udevice *dev, int slot, uint8_t *data)
{
  struct ec_params_vstore_read req;
  struct ec_response_vstore_read *resp;

  req.slot = slot;
  if (ec_command_inptr(dev, EC_CMD_VSTORE_READ, 0, &req, sizeof(req),
           (uint8_t **)&resp, sizeof(*resp)) != sizeof(*resp))
    return -EIO;

  if (!data || req.slot >= EC_VSTORE_SLOT_MAX)
    return -EINVAL;

  memcpy(data, resp->data, sizeof(resp->data));

  return 0;
}

/*
 * cros_ec_vstore_write - Save data into EC vstore slot
 *
 * @slot: vstore slot to write into
 * @data: data to write
 * @size: size of data in bytes
 *
 * Maximum size of data is EC_VSTORE_SLOT_SIZE.  It is the callers
 * responsibility to check the number of implemented slots by
 * querying the vstore info.
 */
int cros_ec_vstore_write(struct udevice *dev, int slot, const uint8_t *data,
       size_t size)
{
  struct ec_params_vstore_write req;

  if (slot >= EC_VSTORE_SLOT_MAX || size > EC_VSTORE_SLOT_SIZE)
    return -EINVAL;

  req.slot = slot;
  memcpy(req.data, data, size);

  if (ec_command(dev, EC_CMD_VSTORE_WRITE, 0, &req, sizeof(req), NULL, 0))
    return -EIO;

  return 0;
}

int cros_ec_get_switches(struct udevice *dev)
{
  struct dm_cros_ec_ops *ops;
  int ret;

  ops = dm_cros_ec_get_ops(dev);
  if (!ops->get_switches)
    return -ENOSYS;

  ret = ops->get_switches(dev);
  if (ret < 0)
    return log_msg_ret("get", ret);

  return ret;
}

int cros_ec_read_batt_charge(struct udevice *dev, uint *chargep)
{
  struct ec_params_charge_state req;
  struct ec_response_charge_state resp;
  int ret;

  req.cmd = CHARGE_STATE_CMD_GET_STATE;
  ret = ec_command(dev, EC_CMD_CHARGE_STATE, 0, &req, sizeof(req),
       &resp, sizeof(resp));
  if (ret)
    return log_msg_ret("read", ret);

  *chargep = resp.get_state.batt_state_of_charge;

  return 0;
}

UCLASS_DRIVER(cros_ec) = {
  .id   = UCLASS_CROS_EC,
  .name   = "cros-ec",
  .per_device_auto  = sizeof(struct cros_ec_dev),
#if CONFIG_IS_ENABLED(OF_REAL)
  .post_bind  = dm_scan_fdt_dev,
#endif
  .flags    = DM_UC_FLAG_ALLOC_PRIV_DMA,
};

Coverage Report

Created: 2026-03-11 06:21