cros: add LPC support for cros_ec

This patch adds LPC support for carrying out the cros_ec protocol.

Signed-off-by: Randall Spangler <rspangler@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Hung-ying Tyan <tyanh@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Hung-ying Tyan 2013-05-15 18:27:31 +08:00 committed by Tom Rini
parent f3424c554c
commit c8d3328a0a
2 changed files with 284 additions and 0 deletions

View file

@ -29,6 +29,7 @@ COBJS-$(CONFIG_ALI152X) += ali512x.o
COBJS-$(CONFIG_DS4510) += ds4510.o
COBJS-$(CONFIG_CBMEM_CONSOLE) += cbmem_console.o
COBJS-$(CONFIG_CROS_EC) += cros_ec.o
COBJS-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o
COBJS-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
COBJS-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
COBJS-$(CONFIG_FSL_IIM) += fsl_iim.o

283
drivers/misc/cros_ec_lpc.c Normal file
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@ -0,0 +1,283 @@
/*
* Chromium OS cros_ec driver - LPC interface
*
* Copyright (c) 2012 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* 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 <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;
}
/**
* 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 Place to put pointer to response data
* @param din_len Maximum size of response in bytes
* @return number of bytes in response, or -1 on error
*/
static int old_lpc_command(struct cros_ec_dev *dev, uint8_t cmd,
const uint8_t *dout, int dout_len,
uint8_t **dinp, int din_len)
{
int ret, i;
if (dout_len > EC_OLD_PARAM_SIZE) {
debug("%s: Cannot send %d bytes\n", __func__, dout_len);
return -1;
}
if (din_len > EC_OLD_PARAM_SIZE) {
debug("%s: Cannot receive %d bytes\n", __func__, din_len);
return -1;
}
if (wait_for_sync(dev)) {
debug("%s: Timeout waiting ready\n", __func__);
return -1;
}
debug_trace("cmd: %02x, ", cmd);
for (i = 0; i < dout_len; i++) {
debug_trace("%02x ", dout[i]);
outb(dout[i], EC_LPC_ADDR_OLD_PARAM + i);
}
outb(cmd, EC_LPC_ADDR_HOST_CMD);
debug_trace("\n");
if (wait_for_sync(dev)) {
debug("%s: Timeout waiting ready\n", __func__);
return -1;
}
ret = inb(EC_LPC_ADDR_HOST_DATA);
if (ret) {
debug("%s: CROS_EC result code %d\n", __func__, ret);
return -ret;
}
debug_trace("resp: %02x, ", ret);
for (i = 0; i < din_len; i++) {
dev->din[i] = inb(EC_LPC_ADDR_OLD_PARAM + i);
debug_trace("%02x ", dev->din[i]);
}
debug_trace("\n");
*dinp = dev->din;
return din_len;
}
int cros_ec_lpc_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version,
const uint8_t *dout, int dout_len,
uint8_t **dinp, int din_len)
{
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;
/* Fall back to old-style command interface if args aren't supported */
if (!dev->cmd_version_is_supported)
return old_lpc_command(dev, cmd, dout, dout_len, dinp,
din_len);
if (dout_len > EC_HOST_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_HOST_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.
*/
int cros_ec_lpc_check_version(struct cros_ec_dev *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)) {
dev->cmd_version_is_supported = 1;
} else {
/* We are going to use the old IO ports */
dev->cmd_version_is_supported = 0;
}
debug("lpc: version %s\n", dev->cmd_version_is_supported ?
"new" : "old");
return 0;
}