xref: /third_party/libwebsockets/lib/drivers/i2c/lws-i2c.c

/*
 * Generic I2C
 *
 * Copyright (C) 2019 - 2020 Andy Green <andy@warmcat.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * These are generic helpers made up of calls to the i2c driver ops, so they
 * just need implementing once like this and are usable for any i2c underlying
 * implementation via the ops.
 */

#include <libwebsockets.h>

int
lws_i2c_command(const lws_i2c_ops_t *ctx, uint8_t ads7, uint8_t c)
{
	if (ctx->start(ctx))
		return 1;

	if (ctx->write(ctx, ads7 << 1)) {
		ctx->stop(ctx);

		return 1;
	}

	ctx->write(ctx, 0);
	ctx->write(ctx, c);
	ctx->stop(ctx);

	return 0;
}

int
lws_i2c_command_list(const lws_i2c_ops_t *ctx, uint8_t ads7, const uint8_t *buf,
		     size_t len)
{
	while (len--)
		if (lws_i2c_command(ctx, ads7, *buf++))
			return 1;

	return 0;
}