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ec/google: Support ChromeOS EC on SPI bus.

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For devices with ChromeOS EC on SPI bus, use the standard SPI driver interface
(see spi-generic.h) to exchange data.

Note: Only EC protocol v3 is supported for SPI bus.

Change-Id: Ia8dcdecd125a2bd7424d0c7560e046b6d6988a03
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/3751
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
This commit is contained in:
Hung-Te Lin
2013-06-26 19:42:12 +08:00
committed by Stefan Reinauer
parent e946f981a4
commit 0ee7062e30
3 changed files with 84 additions and 2 deletions
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65
src/ec/google/chromeec/ec_spi.c Normal file
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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2013 Google Inc. All rights reserved.
*
* 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; version 2 of the License
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <console/console.h>
#include <spi-generic.h>
#include "ec.h"
#include "ec_commands.h"
#define CROSEC_SPI_SPEED (500000)
static int crosec_spi_io(uint8_t *write_bytes, size_t write_size,
uint8_t *read_bytes, size_t read_size,
void *context)
{
struct spi_slave *slave = (struct spi_slave *)context;
int rv;
spi_claim_bus(slave);
rv = spi_xfer(slave, write_bytes, write_size * 8, read_bytes,
read_size * 8);
spi_release_bus(slave);
if (rv != 0) {
printk(BIOS_ERR, "%s: Cannot complete SPI I/O\n", __func__);
return -1;
}
return 0;
}
int google_chromeec_command(struct chromeec_command *cec_command)
{
static struct spi_slave *slave = NULL;
if (!slave) {
slave = spi_setup_slave(CONFIG_EC_GOOGLE_CHROMEEC_SPI_BUS,
CONFIG_EC_GOOGLE_CHROMEEC_SPI_CHIP,
CROSEC_SPI_SPEED,
SPI_READ_FLAG | SPI_WRITE_FLAG);
}
return crosec_command_proto(cec_command, crosec_spi_io, slave);
}
#ifndef __PRE_RAM__
u8 google_chromeec_get_event(void)
{
printk(BIOS_ERR, "%s: Not supported.\n", __func__);
return 0;
}
#endif