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/* Copyright 2016 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <endian.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include "bitutils.h"
#include "operations.h"
#include "debug.h"
struct i2c_data {
int addr;
int fd;
};
static int i2c_set_addr(int fd, int addr)
{
if (ioctl(fd, I2C_SLAVE, addr) < 0) {
PR_ERROR("Unable to set i2c slave address\n");
return -1;
}
return 0;
}
static int i2c_set_scom_addr(struct i2c_data *i2c_data, uint32_t addr)
{
uint8_t data[4];
addr <<= 1;
data[3] = GETFIELD(PPC_BITMASK32(0, 7), addr);
data[2] = GETFIELD(PPC_BITMASK32(8, 15), addr);
data[1] = GETFIELD(PPC_BITMASK32(16, 23), addr);
data[0] = GETFIELD(PPC_BITMASK32(23, 31), addr);
if (write(i2c_data->fd, data, sizeof(data)) != 4) {
PR_ERROR("Error writing address bytes\n");
return -1;
}
return 0;
}
static int i2c_getscom(struct pib *pib, uint64_t addr, uint64_t *value)
{
struct i2c_data *i2c_data = pib->priv;
uint64_t data;
CHECK_ERR(i2c_set_scom_addr(i2c_data, addr));
if (read(i2c_data->fd, &data, sizeof(data)) != 8) {
PR_ERROR("Error reading data\n");
return -1;
}
*value = le64toh(data);
return 0;
}
static int i2c_putscom(struct pib *pib, uint64_t addr, uint64_t value)
{
struct i2c_data *i2c_data = pib->priv;
uint8_t data[12];
/* Setup scom address */
addr <<= 1;
data[3] = GETFIELD(PPC_BITMASK32(0, 7), addr);
data[2] = GETFIELD(PPC_BITMASK32(8, 15), addr);
data[1] = GETFIELD(PPC_BITMASK32(16, 23), addr);
data[0] = GETFIELD(PPC_BITMASK32(23, 31), addr);
/* Add data value */
data[11] = GETFIELD(PPC_BITMASK(0, 7), value);
data[10] = GETFIELD(PPC_BITMASK(8, 15), value);
data[9] = GETFIELD(PPC_BITMASK(16, 23), value);
data[8] = GETFIELD(PPC_BITMASK(23, 31), value);
data[7] = GETFIELD(PPC_BITMASK(32, 39), value);
data[6] = GETFIELD(PPC_BITMASK(40, 47), value);
data[5] = GETFIELD(PPC_BITMASK(48, 55), value);
data[4] = GETFIELD(PPC_BITMASK(56, 63), value);
/* Write value */
if (write(i2c_data->fd, data, sizeof(data)) != 12) {
PR_ERROR("Error writing data bytes\n");
return -1;
}
return 0;
}
#if 0
/* TODO: At present we don't have a generic destroy method as there aren't many
* use cases for it. So for the moment we can just let the OS close the file
* descriptor on exit. */
static void i2c_destroy(struct pib *pib)
{
struct i2c_data *i2c_data = pib->priv;
close(i2c_data->fd);
free(i2c_data);
}
#endif
/*
* Initialise a i2c backend on the given bus at the given bus address.
*/
int i2c_target_probe(struct pdbg_target *target)
{
struct pib *pib = target_to_pib(target);
struct i2c_data *i2c_data;
const char *bus;
int addr;
bus = pdbg_target_property(&pib->target, "bus", NULL);
if (!bus)
bus = "/dev/i2c4";
addr = pdbg_target_address(&pib->target, NULL);
assert(addr);
i2c_data = malloc(sizeof(*i2c_data));
if (!i2c_data)
exit(1);
i2c_data->addr = addr;
i2c_data->fd = open(bus, O_RDWR);
if (i2c_data->fd < 0) {
perror("Error opening bus");
return -1;
}
if (i2c_set_addr(i2c_data->fd, addr) < 0)
return -1;
pib->priv = i2c_data;
return 0;
}
static struct pib p8_i2c_pib = {
.target = {
.name = "POWER8 I2C Slave",
.compatible = "ibm,power8-i2c-slave",
.class = "pib",
.probe = i2c_target_probe,
},
.read = i2c_getscom,
.write = i2c_putscom,
};
DECLARE_HW_UNIT(p8_i2c_pib);
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