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/*
* Chromium OS cros_ec driver - I2C 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 <dm.h>
#include <i2c.h>
#include <cros_ec.h>
#ifdef DEBUG_TRACE
#define debug_trace(fmt, b...) debug(fmt, #b)
#else
#define debug_trace(fmt, b...)
#endif
static int cros_ec_i2c_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 = udev->uclass_priv;
/* version8, cmd8, arglen8, out8[dout_len], csum8 */
int out_bytes = dout_len + 4;
/* response8, arglen8, in8[din_len], checksum8 */
int in_bytes = din_len + 3;
uint8_t *ptr;
/* Receive input data, so that args will be dword aligned */
uint8_t *in_ptr;
int len, csum, ret;
/*
* Sanity-check I/O sizes given transaction overhead in internal
* buffers.
*/
if (out_bytes > sizeof(dev->dout)) {
debug("%s: Cannot send %d bytes\n", __func__, dout_len);
return -1;
}
if (in_bytes > sizeof(dev->din)) {
debug("%s: Cannot receive %d bytes\n", __func__, din_len);
return -1;
}
assert(dout_len >= 0);
assert(dinp);
/*
* Copy command and data into output buffer so we can do a single I2C
* burst transaction.
*/
ptr = dev->dout;
/*
* in_ptr starts of pointing to a dword-aligned input data buffer.
* We decrement it back by the number of header bytes we expect to
* receive, so that the first parameter of the resulting input data
* will be dword aligned.
*/
in_ptr = dev->din + sizeof(int64_t);
if (dev->protocol_version != 2) {
/* Something we don't support */
debug("%s: Protocol version %d unsupported\n",
__func__, dev->protocol_version);
return -1;
}
*ptr++ = EC_CMD_VERSION0 + cmd_version;
*ptr++ = cmd;
*ptr++ = dout_len;
in_ptr -= 2; /* Expect status, length bytes */
memcpy(ptr, dout, dout_len);
ptr += dout_len;
*ptr++ = (uint8_t)
cros_ec_calc_checksum(dev->dout, dout_len + 3);
/* Send output data */
cros_ec_dump_data("out", -1, dev->dout, out_bytes);
ret = dm_i2c_write(udev, 0, dev->dout, out_bytes);
if (ret) {
debug("%s: Cannot complete I2C write to %s\n", __func__,
udev->name);
ret = -1;
}
if (!ret) {
ret = dm_i2c_read(udev, 0, in_ptr, in_bytes);
if (ret) {
debug("%s: Cannot complete I2C read from %s\n",
__func__, udev->name);
ret = -1;
}
}
if (*in_ptr != EC_RES_SUCCESS) {
debug("%s: Received bad result code %d\n", __func__, *in_ptr);
return -(int)*in_ptr;
}
len = in_ptr[1];
if (len + 3 > sizeof(dev->din)) {
debug("%s: Received length %#02x too large\n",
__func__, len);
return -1;
}
csum = cros_ec_calc_checksum(in_ptr, 2 + len);
if (csum != in_ptr[2 + len]) {
debug("%s: Invalid checksum rx %#02x, calced %#02x\n",
__func__, in_ptr[2 + din_len], csum);
return -1;
}
din_len = min(din_len, len);
cros_ec_dump_data("in", -1, in_ptr, din_len + 3);
/* Return pointer to dword-aligned input data, if any */
*dinp = dev->din + sizeof(int64_t);
return din_len;
}
static int cros_ec_probe(struct udevice *dev)
{
return cros_ec_register(dev);
}
static struct dm_cros_ec_ops cros_ec_ops = {
.command = cros_ec_i2c_command,
};
static const struct udevice_id cros_ec_ids[] = {
{ .compatible = "google,cros-ec" },
{ }
};
U_BOOT_DRIVER(cros_ec_i2c) = {
.name = "cros_ec",
.id = UCLASS_CROS_EC,
.of_match = cros_ec_ids,
.probe = cros_ec_probe,
.ops = &cros_ec_ops,
};
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