static void handle_rpc_func_cmd_i2c_transfer()

in optee/rpc.c [36:121]

• 74 lines of code
• 13 McCabe index (conditional complexity)

static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx,
					     struct optee_msg_arg *arg)
{
	struct optee *optee = tee_get_drvdata(ctx->teedev);
	struct tee_param *params;
	struct i2c_adapter *adapter;
	struct i2c_msg msg = { };
	size_t i;
	int ret = -EOPNOTSUPP;
	u8 attr[] = {
		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
		TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT,
	};

	if (arg->num_params != ARRAY_SIZE(attr)) {
		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
		return;
	}

	params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
			       GFP_KERNEL);
	if (!params) {
		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
		return;
	}

	if (optee->ops->from_msg_param(optee, params, arg->num_params,
				       arg->params))
		goto bad;

	for (i = 0; i < arg->num_params; i++) {
		if (params[i].attr != attr[i])
			goto bad;
	}

	adapter = i2c_get_adapter(params[0].u.value.b);
	if (!adapter)
		goto bad;

	if (params[1].u.value.a & OPTEE_RPC_I2C_FLAGS_TEN_BIT) {
		if (!i2c_check_functionality(adapter,
					     I2C_FUNC_10BIT_ADDR)) {
			i2c_put_adapter(adapter);
			goto bad;
		}

		msg.flags = I2C_M_TEN;
	}

	msg.addr = params[0].u.value.c;
	msg.buf  = params[2].u.memref.shm->kaddr;
	msg.len  = params[2].u.memref.size;

	switch (params[0].u.value.a) {
	case OPTEE_RPC_I2C_TRANSFER_RD:
		msg.flags |= I2C_M_RD;
		break;
	case OPTEE_RPC_I2C_TRANSFER_WR:
		break;
	default:
		i2c_put_adapter(adapter);
		goto bad;
	}

	ret = i2c_transfer(adapter, &msg, 1);

	if (ret < 0) {
		arg->ret = TEEC_ERROR_COMMUNICATION;
	} else {
		params[3].u.value.a = msg.len;
		if (optee->ops->to_msg_param(optee, arg->params,
					     arg->num_params, params))
			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
		else
			arg->ret = TEEC_SUCCESS;
	}

	i2c_put_adapter(adapter);
	kfree(params);
	return;
bad:
	kfree(params);
	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}