u-boot/drivers/misc/cros_ec_i2c.c
Simon Glass 3fbb78711c cros_ec: exynos: Match up device tree with kernel version
The U-Boot device trees are slightly different in a few places. Adjust them
to remove most of the differences. Note that U-Boot does not support the
concept of interrupts as distinct from GPIOs, so this difference remains.

For sandbox, use the same keyboard file as for ARM boards and drop the
host emulation bus which seems redundant.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-04-18 11:11:16 -06:00

153 lines
3.7 KiB
C

/*
* 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 = dev_get_uclass_priv(udev);
/* 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-i2c" },
{ }
};
U_BOOT_DRIVER(cros_ec_i2c) = {
.name = "cros_ec_i2c",
.id = UCLASS_CROS_EC,
.of_match = cros_ec_ids,
.probe = cros_ec_probe,
.ops = &cros_ec_ops,
};