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/*
* This file is part of the flashrom project.
*
* Copyright (C) 2023 Steve Markgraf <steve@steve-m.de>
*
* 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 <stdlib.h>
#include <string.h>
#include <limits.h>
#include <errno.h>
#include <gpiod.h>
#include "programmer.h"
#include "bitbang_spi.h"
#include "spi.h"
#include "flash.h"
#define CONSUMER "flashprog"
struct linux_gpio_spi {
struct gpiod_chip *chip;
struct gpiod_line_bulk bulk;
struct gpiod_line *cs_line, *sck_line, *mosi_line, *miso_line;
};
static void linux_gpio_spi_bitbang_set_cs(int val, void *spi_data)
{
struct linux_gpio_spi *data = spi_data;
if (gpiod_line_set_value(data->cs_line, val) < 0)
msg_perr("Setting cs line failed\n");
}
static void linux_gpio_spi_bitbang_set_sck(int val, void *spi_data)
{
struct linux_gpio_spi *data = spi_data;
if (gpiod_line_set_value(data->sck_line, val) < 0)
msg_perr("Setting sck line failed\n");
}
static void linux_gpio_spi_bitbang_set_mosi(int val, void *spi_data)
{
struct linux_gpio_spi *data = spi_data;
if (gpiod_line_set_value(data->mosi_line, val) < 0)
msg_perr("Setting sck line failed\n");
}
static int linux_gpio_spi_bitbang_get_miso(void *spi_data)
{
struct linux_gpio_spi *data = spi_data;
int r = gpiod_line_get_value(data->miso_line);
if (r < 0)
msg_perr("Getting miso line failed\n");
return r;
}
static const struct bitbang_spi_master bitbang_spi_master_gpiod = {
.set_cs = linux_gpio_spi_bitbang_set_cs,
.set_sck = linux_gpio_spi_bitbang_set_sck,
.set_mosi = linux_gpio_spi_bitbang_set_mosi,
.get_miso = linux_gpio_spi_bitbang_get_miso,
};
static int linux_gpio_spi_shutdown(void *spi_data)
{
struct linux_gpio_spi *data = spi_data;
if (gpiod_line_bulk_num_lines(&data->bulk) > 0)
gpiod_line_release_bulk(&data->bulk);
if (data->chip)
gpiod_chip_close(data->chip);
free(data);
return 0;
}
static int linux_gpio_spi_init(struct flashprog_programmer *const prog)
{
struct linux_gpio_spi *data = NULL;
struct gpiod_chip *chip = NULL;
const char *param_str[] = { "cs", "sck", "mosi", "miso", "gpiochip" };
const bool param_required[] = { true, true, true, true, false };
unsigned int param_int[ARRAY_SIZE(param_str)];
unsigned int i;
int r;
data = calloc(1, sizeof(*data));
if (!data) {
msg_perr("Unable to allocate space for SPI master data\n");
return 1;
}
for (i = 0; i < ARRAY_SIZE(param_str); i++) {
char *param = extract_programmer_param(param_str[i]);
char *endptr;
r = 1;
if (param) {
errno = 0;
param_int[i] = strtoul(param, &endptr, 10);
r = (*endptr != '\0') || (errno != 0);
free(param);
} else {
param_int[i] = UINT_MAX;
}
if ((param_required[i] || param) && r) {
msg_perr("Missing or invalid required programmer "
"parameter %s=<n>\n", param_str[i]);
goto err_exit;
}
}
char *const dev = extract_programmer_param("dev");
if (!dev && param_int[4] == UINT_MAX) {
msg_perr("Either a 'dev' or 'gpiochip' parameter must be specified.\n");
goto err_exit;
}
if (dev && param_int[4] != UINT_MAX) {
msg_perr("Only one of 'dev' or 'gpiochip' parameters can be specified.\n");
free(dev);
goto err_exit;
}
if (dev) {
chip = gpiod_chip_open(dev);
free(dev);
} else {
chip = gpiod_chip_open_by_number(param_int[4]);
}
if (!chip) {
msg_perr("Failed to open gpiochip: %s\n", strerror(errno));
goto err_exit;
}
data->chip = chip;
if (gpiod_chip_get_lines(chip, param_int, 4, &data->bulk)) {
msg_perr("Error getting GPIO lines\n");
goto err_exit;
}
data->cs_line = gpiod_line_bulk_get_line(&data->bulk, 0);
data->sck_line = gpiod_line_bulk_get_line(&data->bulk, 1);
data->mosi_line = gpiod_line_bulk_get_line(&data->bulk, 2);
data->miso_line = gpiod_line_bulk_get_line(&data->bulk, 3);
r = gpiod_line_request_output(data->cs_line, CONSUMER, 1);
r |= gpiod_line_request_output(data->sck_line, CONSUMER, 1);
r |= gpiod_line_request_output(data->mosi_line, CONSUMER, 1);
r |= gpiod_line_request_input(data->miso_line, CONSUMER);
if (r < 0) {
msg_perr("Requesting GPIO lines failed\n");
goto err_exit;
}
if (register_shutdown(linux_gpio_spi_shutdown, data))
goto err_exit;
/* shutdown function does the cleanup */
return register_spi_bitbang_master(&bitbang_spi_master_gpiod, data);
err_exit:
linux_gpio_spi_shutdown(data);
return 1;
}
const struct programmer_entry programmer_linux_gpio_spi = {
.name = "linux_gpio_spi",
.type = OTHER,
.devs.note = "Device file /dev/gpiochip<n>\n",
.init = linux_gpio_spi_init,
};
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