u-boot/drivers/misc/cros_ec_lpc.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

219 lines
5.2 KiB
C

/*
* 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 <dm.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 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);
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_PROTO2_MAX_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_PROTO2_MAX_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.
*/
static int cros_ec_lpc_check_version(struct udevice *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;
}
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_lpc_command,
.check_version = cros_ec_lpc_check_version,
};
static const struct udevice_id cros_ec_ids[] = {
{ .compatible = "google,cros-ec-lpc" },
{ }
};
U_BOOT_DRIVER(cros_ec_lpc) = {
.name = "cros_ec_lpc",
.id = UCLASS_CROS_EC,
.of_match = cros_ec_ids,
.probe = cros_ec_probe,
.ops = &cros_ec_ops,
};