u-boot/drivers/misc/cros_ec_spi.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

192 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Chromium OS cros_ec driver - SPI 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 <common.h>
#include <cros_ec.h>
#include <dm.h>
#include <errno.h>
#include <spi.h>
int cros_ec_spi_packet(struct udevice *udev, int out_bytes, int in_bytes)
{
struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
struct spi_slave *slave = dev_get_parent_priv(dev->dev);
ulong start;
uint8_t byte;
int rv;
/* Do the transfer */
if (spi_claim_bus(slave)) {
debug("%s: Cannot claim SPI bus\n", __func__);
return -1;
}
rv = spi_xfer(slave, out_bytes * 8, dev->dout, NULL, SPI_XFER_BEGIN);
if (rv)
goto done;
start = get_timer(0);
while (1) {
rv = spi_xfer(slave, 8, NULL, &byte, 0);
if (byte == SPI_PREAMBLE_END_BYTE)
break;
if (rv)
goto done;
if (get_timer(start) > 100) {
rv = -ETIMEDOUT;
goto done;
}
}
rv = spi_xfer(slave, in_bytes * 8, NULL, dev->din, 0);
done:
spi_xfer(slave, 0, NULL, NULL, SPI_XFER_END);
spi_release_bus(slave);
if (rv) {
debug("%s: Cannot complete SPI transfer\n", __func__);
return -1;
}
return in_bytes;
}
/**
* Send a command to a LPC 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 Returns pointer to response data. This will be
* untouched unless we return a value > 0.
* @param din_len Maximum size of response in bytes
* @return number of bytes in response, or -1 on error
*/
int cros_ec_spi_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);
struct spi_slave *slave = dev_get_parent_priv(dev->dev);
int in_bytes = din_len + 4; /* status, length, checksum, trailer */
uint8_t *out;
uint8_t *p;
int csum, len;
int rv;
if (dev->protocol_version != 2) {
debug("%s: Unsupported EC protcol version %d\n",
__func__, dev->protocol_version);
return -1;
}
/*
* Sanity-check input size to make sure it plus transaction overhead
* fits in the internal device buffer.
*/
if (in_bytes > sizeof(dev->din)) {
debug("%s: Cannot receive %d bytes\n", __func__, din_len);
return -1;
}
/* We represent message length as a byte */
if (dout_len > 0xff) {
debug("%s: Cannot send %d bytes\n", __func__, dout_len);
return -1;
}
/*
* Clear input buffer so we don't get false hits for MSG_HEADER
*/
memset(dev->din, '\0', in_bytes);
if (spi_claim_bus(slave)) {
debug("%s: Cannot claim SPI bus\n", __func__);
return -1;
}
out = dev->dout;
out[0] = EC_CMD_VERSION0 + cmd_version;
out[1] = cmd;
out[2] = (uint8_t)dout_len;
memcpy(out + 3, dout, dout_len);
csum = cros_ec_calc_checksum(out, 3)
+ cros_ec_calc_checksum(dout, dout_len);
out[3 + dout_len] = (uint8_t)csum;
/*
* Send output data and receive input data starting such that the
* message body will be dword aligned.
*/
p = dev->din + sizeof(int64_t) - 2;
len = dout_len + 4;
cros_ec_dump_data("out", cmd, out, len);
rv = spi_xfer(slave, max(len, in_bytes) * 8, out, p,
SPI_XFER_BEGIN | SPI_XFER_END);
spi_release_bus(slave);
if (rv) {
debug("%s: Cannot complete SPI transfer\n", __func__);
return -1;
}
len = min((int)p[1], din_len);
cros_ec_dump_data("in", -1, p, len + 3);
/* Response code is first byte of message */
if (p[0] != EC_RES_SUCCESS) {
printf("%s: Returned status %d\n", __func__, p[0]);
return -(int)(p[0]);
}
/* Check checksum */
csum = cros_ec_calc_checksum(p, len + 2);
if (csum != p[len + 2]) {
debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__,
p[2 + len], csum);
return -1;
}
/* Anything else is the response data */
*dinp = p + 2;
return len;
}
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_spi_packet,
.command = cros_ec_spi_command,
};
static const struct udevice_id cros_ec_ids[] = {
{ .compatible = "google,cros-ec-spi" },
{ }
};
U_BOOT_DRIVER(cros_ec_spi) = {
.name = "cros_ec_spi",
.id = UCLASS_CROS_EC,
.of_match = cros_ec_ids,
.probe = cros_ec_probe,
.ops = &cros_ec_ops,
};