/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2015 Sergey Alirzaev <zl29ah@gmail.com>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <ftdi.h>
#include <libusb.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"

static const uint32_t scanopts[] = {
	SR_CONF_CONN,
};

static const uint32_t devopts[] = {
	SR_CONF_LOGIC_ANALYZER,
	SR_CONF_CONTINUOUS,
	SR_CONF_LIMIT_SAMPLES | SR_CONF_SET,
	SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
	SR_CONF_CONN | SR_CONF_GET,
};

static const uint64_t samplerates[] = {
	SR_HZ(3600),
	SR_MHZ(10),
	SR_HZ(1),
};

static const struct ftdi_chip_desc ft2232h_desc = {
	.vendor = 0x0403,
	.product = 0x6010,
	.samplerate_div = 20,
	.channel_names = {
		"ADBUS0",
		"ADBUS1",
		"ADBUS2",
		"ADBUS3",
		"ADBUS4",
		"ADBUS5",
		"ADBUS6",
		"ADBUS7",
		/* TODO: BDBUS[0..7] channels. */
		NULL
	}
};

static const struct ftdi_chip_desc ft232r_desc = {
	.vendor = 0x0403,
	.product = 0x6001,
	.samplerate_div = 30,
	.channel_names = {
		"TXD",
		"RXD",
		"RTS#",
		"CTS#",
		"DTR#",
		"DSR#",
		"DCD#",
		"RI#",
		NULL
	}
};

static const struct ftdi_chip_desc *chip_descs[] = {
	&ft2232h_desc,
	&ft232r_desc,
};

static void scan_device(struct ftdi_context *ftdic,
	struct libusb_device *dev, GSList **devices)
{
	struct libusb_device_descriptor usb_desc;
	const struct ftdi_chip_desc *desc;
	struct dev_context *devc;
	char *vendor, *model, *serial_num;
	struct sr_dev_inst *sdi;
	int rv;

	libusb_get_device_descriptor(dev, &usb_desc);

	desc = NULL;
	for (unsigned long i = 0; i < ARRAY_SIZE(chip_descs); i++) {
		desc = chip_descs[i];
		if (desc->vendor == usb_desc.idVendor &&
			desc->product == usb_desc.idProduct)
			break;
	}

	if (!desc) {
		sr_spew("Unsupported FTDI device 0x%4x:0x%4x.",
			usb_desc.idVendor, usb_desc.idProduct);
		return;
	}

	/* Allocate memory for our private device context. */
	devc = g_malloc0(sizeof(struct dev_context));

	/* Allocate memory for the incoming data. */
	devc->data_buf = g_malloc0(DATA_BUF_SIZE);

	devc->desc = desc;

	vendor = g_malloc(32);
	model = g_malloc(32);
	serial_num = g_malloc(32);
	rv = ftdi_usb_get_strings(ftdic, dev, vendor, 32,
			model, 32, serial_num, 32);
	switch (rv) {
	case 0:
		break;
	case -9:
		sr_dbg("The device lacks a serial number.");
		g_free(serial_num);
		serial_num = NULL;
		break;
	default:
		sr_err("Failed to get the FTDI strings: %d", rv);
		goto err_free_strings;
	}
	sr_dbg("Found an FTDI device: %s.", model);

	/* Register the device with libsigrok. */
	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	sdi->status = SR_ST_INACTIVE;
	sdi->vendor = vendor;
	sdi->model = model;
	sdi->serial_num = serial_num;
	sdi->priv = devc;
	sdi->connection_id = g_strdup_printf("d:%u/%u",
		libusb_get_bus_number(dev), libusb_get_device_address(dev));

	for (char *const *chan = &(desc->channel_names[0]); *chan; chan++)
		sr_channel_new(sdi, chan - &(desc->channel_names[0]),
				SR_CHANNEL_LOGIC, TRUE, *chan);

	*devices = g_slist_append(*devices, sdi);
	return;

err_free_strings:
	g_free(vendor);
	g_free(model);
	g_free(serial_num);
	g_free(devc->data_buf);
	g_free(devc);
}

static GSList *scan_all(struct ftdi_context *ftdic, GSList *options)
{
	GSList *devices;
	struct ftdi_device_list *devlist = 0;
	struct ftdi_device_list *curdev;
	int ret;

	(void)options;

	devices = NULL;

	ret = ftdi_usb_find_all(ftdic, &devlist, 0, 0);
	if (ret < 0) {
		sr_err("Failed to list devices (%d): %s", ret,
		       ftdi_get_error_string(ftdic));
		return NULL;
	}

	sr_dbg("Number of FTDI devices found: %d", ret);

	curdev = devlist;
	while (curdev) {
		scan_device(ftdic, curdev->dev, &devices);
		curdev = curdev->next;
	}

	ftdi_list_free(&devlist);

	return devices;
}

static GSList *scan(struct sr_dev_driver *di, GSList *options)
{
	struct ftdi_context *ftdic;
	struct sr_config *src;
	struct sr_usb_dev_inst *usb;
	const char *conn;
	GSList *l, *conn_devices;
	GSList *devices;
	struct drv_context *drvc;
	libusb_device **devlist;
	int i;

	drvc = di->context;
	conn = NULL;
	for (l = options; l; l = l->next) {
		src = l->data;
		if (src->key == SR_CONF_CONN) {
			conn = g_variant_get_string(src->data, NULL);
			break;
		}
	}

	/* Allocate memory for the FTDI context (ftdic) and initialize it. */
	ftdic = ftdi_new();
	if (!ftdic) {
		sr_err("Failed to initialize libftdi.");
		return NULL;
	}

	if (conn) {
		devices = NULL;
		libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
		for (i = 0; devlist[i]; i++) {
			conn_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn);
			for (l = conn_devices; l; l = l->next) {
				usb = l->data;
				if (usb->bus == libusb_get_bus_number(devlist[i])
					&& usb->address == libusb_get_device_address(devlist[i])) {
					scan_device(ftdic, devlist[i], &devices);
				}
			}
		}
		libusb_free_device_list(devlist, 1);
	} else
		devices = scan_all(ftdic, options);

	ftdi_free(ftdic);

	return std_scan_complete(di, devices);
}

static void clear_helper(void *priv)
{
	struct dev_context *devc;

	devc = priv;
	g_free(devc->data_buf);
	g_free(devc);
}

static int dev_clear(const struct sr_dev_driver *di)
{
	return std_dev_clear(di, clear_helper);
}

static int dev_open(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	int ret = SR_OK;

	devc = sdi->priv;

	devc->ftdic = ftdi_new();
	if (!devc->ftdic)
		return SR_ERR;

	ret = ftdi_usb_open_string(devc->ftdic, sdi->connection_id);
	if (ret < 0) {
		/* Log errors, except for -3 ("device not found"). */
		if (ret != -3)
			sr_err("Failed to open device (%d): %s", ret,
			       ftdi_get_error_string(devc->ftdic));
		goto err_ftdi_free;
	}

	/* Purge RX/TX buffers in the FTDI chip. */
	ret = ftdi_usb_purge_buffers(devc->ftdic);
	if (ret < 0) {
		sr_err("Failed to purge FTDI RX/TX buffers (%d): %s.",
		       ret, ftdi_get_error_string(devc->ftdic));
		goto err_dev_open_close_ftdic;
	}
	sr_dbg("FTDI chip buffers purged successfully.");

	/* Reset the FTDI bitmode. */
	ret = ftdi_set_bitmode(devc->ftdic, 0x00, BITMODE_RESET);
	if (ret < 0) {
		sr_err("Failed to reset the FTDI chip bitmode (%d): %s.",
		       ret, ftdi_get_error_string(devc->ftdic));
		goto err_dev_open_close_ftdic;
	}
	sr_dbg("FTDI chip bitmode reset successfully.");

	ret = ftdi_set_bitmode(devc->ftdic, 0x00, BITMODE_BITBANG);
	if (ret < 0) {
		sr_err("Failed to put FTDI chip into bitbang mode (%d): %s.",
		       ret, ftdi_get_error_string(devc->ftdic));
		goto err_dev_open_close_ftdic;
	}
	sr_dbg("FTDI chip bitbang mode entered successfully.");

	sdi->status = SR_ST_ACTIVE;

	return SR_OK;
err_dev_open_close_ftdic:
	ftdi_usb_close(devc->ftdic);
err_ftdi_free:
	ftdi_free(devc->ftdic);
	return SR_ERR;
}

static int dev_close(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;

	devc = sdi->priv;

	if (devc->ftdic) {
		ftdi_usb_close(devc->ftdic);
		ftdi_free(devc->ftdic);
		devc->ftdic = NULL;
	}

	sdi->status = SR_ST_INACTIVE;

	return SR_OK;
}

static int config_get(uint32_t key, GVariant **data,
	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
{
	int ret;
	struct dev_context *devc;
	struct sr_usb_dev_inst *usb;
	char str[128];

	(void)cg;

	devc = sdi->priv;

	ret = SR_OK;
	switch (key) {
	case SR_CONF_SAMPLERATE:
		*data = g_variant_new_uint64(devc->cur_samplerate);
		break;
	case SR_CONF_CONN:
		if (!sdi || !sdi->conn)
			return SR_ERR_ARG;
		usb = sdi->conn;
		snprintf(str, 128, "%d.%d", usb->bus, usb->address);
		*data = g_variant_new_string(str);
		break;
	default:
		return SR_ERR_NA;
	}

	return ret;
}

static int config_set(uint32_t key, GVariant *data,
	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
{
	int ret;
	struct dev_context *devc;
	uint64_t value;

	(void)cg;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR_DEV_CLOSED;

	devc = sdi->priv;

	ret = SR_OK;
	switch (key) {
	case SR_CONF_LIMIT_MSEC:
		value = g_variant_get_uint64(data);
		/* TODO: Implement. */
		ret = SR_ERR_NA;
		break;
	case SR_CONF_LIMIT_SAMPLES:
		if (g_variant_get_uint64(data) == 0)
			return SR_ERR_ARG;
		devc->limit_samples = g_variant_get_uint64(data);
		break;
	case SR_CONF_SAMPLERATE:
		value = g_variant_get_uint64(data);
		if (value < 3600)
			return SR_ERR_SAMPLERATE;
		devc->cur_samplerate = value;
		return ftdi_la_set_samplerate(devc);
	default:
		ret = SR_ERR_NA;
	}

	return ret;
}

static int config_list(uint32_t key, GVariant **data,
	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
{
	int ret;
	GVariant *gvar;
	GVariantBuilder gvb;

	(void)sdi;
	(void)cg;

	ret = SR_OK;
	switch (key) {
	case SR_CONF_SCAN_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
			scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
		break;
	case SR_CONF_DEVICE_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
			devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
		break;
	case SR_CONF_SAMPLERATE:
		g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
		gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
			samplerates, ARRAY_SIZE(samplerates), sizeof(uint64_t));
		g_variant_builder_add(&gvb, "{sv}", "samplerate-steps", gvar);
		*data = g_variant_builder_end(&gvb);
		break;
	default:
		return SR_ERR_NA;
	}

	return ret;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc;

	devc = sdi->priv;

	if (!devc->ftdic)
		return SR_ERR_BUG;

	ftdi_set_bitmode(devc->ftdic, 0, BITMODE_BITBANG);

	/* Properly reset internal variables before every new acquisition. */
	devc->samples_sent = 0;
	devc->bytes_received = 0;

	std_session_send_df_header(sdi);

	/* Hook up a dummy handler to receive data from the device. */
	sr_session_source_add(sdi->session, -1, G_IO_IN, 0,
			      ftdi_la_receive_data, (void *)sdi);

	return SR_OK;
}

static int dev_acquisition_stop(struct sr_dev_inst *sdi)
{
	sr_session_source_remove(sdi->session, -1);

	std_session_send_df_end(sdi);

	return SR_OK;
}

static struct sr_dev_driver ftdi_la_driver_info = {
	.name = "ftdi-la",
	.longname = "FTDI LA",
	.api_version = 1,
	.init = std_init,
	.cleanup = std_cleanup,
	.scan = scan,
	.dev_list = std_dev_list,
	.dev_clear = dev_clear,
	.config_get = config_get,
	.config_set = config_set,
	.config_list = config_list,
	.dev_open = dev_open,
	.dev_close = dev_close,
	.dev_acquisition_start = dev_acquisition_start,
	.dev_acquisition_stop = dev_acquisition_stop,
	.context = NULL,
};
SR_REGISTER_DEV_DRIVER(ftdi_la_driver_info);