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/*
* This file is part of the coreboot project.
*
* Copyright 2016 Google Inc.
*
* 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.
*/
#include <assert.h>
#include <spi-generic.h>
#include <string.h>
int spi_claim_bus(const struct spi_slave *slave)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
if (ctrlr && ctrlr->claim_bus)
return ctrlr->claim_bus(slave);
return 0;
}
void spi_release_bus(const struct spi_slave *slave)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
if (ctrlr && ctrlr->release_bus)
ctrlr->release_bus(slave);
}
static int spi_xfer_single_op(const struct spi_slave *slave,
struct spi_op *op)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
int ret;
if (!ctrlr || !ctrlr->xfer)
return -1;
ret = ctrlr->xfer(slave, op->dout, op->bytesout, op->din, op->bytesin);
if (ret)
op->status = SPI_OP_FAILURE;
else
op->status = SPI_OP_SUCCESS;
return ret;
}
static int spi_xfer_vector_default(const struct spi_slave *slave,
struct spi_op vectors[], size_t count)
{
size_t i;
int ret;
for (i = 0; i < count; i++) {
ret = spi_xfer_single_op(slave, &vectors[i]);
if (ret)
return ret;
}
return 0;
}
int spi_xfer_vector(const struct spi_slave *slave,
struct spi_op vectors[], size_t count)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
if (ctrlr && ctrlr->xfer_vector)
return ctrlr->xfer_vector(slave, vectors, count);
return spi_xfer_vector_default(slave, vectors, count);
}
int spi_xfer(const struct spi_slave *slave, const void *dout, size_t bytesout,
void *din, size_t bytesin)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
if (ctrlr && ctrlr->xfer)
return ctrlr->xfer(slave, dout, bytesout, din, bytesin);
return -1;
}
unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len,
unsigned int buf_len)
{
const struct spi_ctrlr *ctrlr = slave->ctrlr;
unsigned int ctrlr_max;
bool deduct_cmd_len;
bool deduct_opcode_len;
if (!ctrlr)
return 0;
deduct_cmd_len = !!(ctrlr->flags & SPI_CNTRLR_DEDUCT_CMD_LEN);
deduct_opcode_len = !!(ctrlr->flags & SPI_CNTRLR_DEDUCT_OPCODE_LEN);
ctrlr_max = ctrlr->max_xfer_size;
assert (ctrlr_max != 0);
/* Assume opcode is always one byte and deduct it from the cmd_len
as the hardware has a separate register for the opcode. */
if (deduct_opcode_len)
cmd_len--;
if (deduct_cmd_len && (ctrlr_max > cmd_len))
ctrlr_max -= cmd_len;
return min(ctrlr_max, buf_len);
}
void __attribute__((weak)) spi_init(void)
{
/* Default weak implementation - do nothing. */
}
int spi_setup_slave(unsigned int bus, unsigned int cs, struct spi_slave *slave)
{
size_t i;
memset(slave, 0, sizeof(*slave));
for (i = 0; i < spi_ctrlr_bus_map_count; i++) {
if ((spi_ctrlr_bus_map[i].bus_start <= bus) &&
(spi_ctrlr_bus_map[i].bus_end >= bus)) {
slave->ctrlr = spi_ctrlr_bus_map[i].ctrlr;
break;
}
}
if (slave->ctrlr == NULL)
return -1;
slave->bus = bus;
slave->cs = cs;
if (slave->ctrlr->setup)
return slave->ctrlr->setup(slave);
return 0;
}
static int spi_xfer_combine_two_vectors(const struct spi_slave *slave,
struct spi_op *v1, struct spi_op *v2)
{
struct spi_op op = {
.dout = v1->dout, .bytesout = v1->bytesout,
.din = v2->din, .bytesin = v2->bytesin,
};
int ret;
/*
* Combine two vectors only if:
* v1 has non-NULL dout and NULL din and
* v2 has non-NULL din and NULL dout and
*
* In all other cases, do not combine the two vectors.
*/
if ((!v1->dout || v1->din) || (v2->dout || !v2->din))
return -1;
ret = spi_xfer_single_op(slave, &op);
v1->status = v2->status = op.status;
return ret;
}
/*
* Helper function to allow chipsets to combine two vectors if possible. This
* function can only handle upto 2 vectors.
*
* Two vectors are combined if first vector has a non-NULL dout and NULL din and
* second vector has a non-NULL din and NULL dout. Otherwise, each vector is
* operated upon one at a time.
*
* Returns 0 on success and non-zero on failure.
*/
int spi_xfer_two_vectors(const struct spi_slave *slave,
struct spi_op vectors[], size_t count)
{
int ret;
assert (count <= 2);
if (count == 2) {
ret = spi_xfer_combine_two_vectors(slave, &vectors[0],
&vectors[1]);
if (!ret || (vectors[0].status != SPI_OP_NOT_EXECUTED))
return ret;
}
return spi_xfer_vector_default(slave, vectors, count);
}
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