static int aspeed_vuart_probe()

in serial/8250/8250_aspeed_vuart.c [412:568]

• 122 lines of code
• 21 McCabe index (conditional complexity)

static int aspeed_vuart_probe(struct platform_device *pdev)
{
	struct of_phandle_args sirq_polarity_sense_args;
	struct uart_8250_port port;
	struct aspeed_vuart *vuart;
	struct device_node *np;
	struct resource *res;
	u32 clk, prop, sirq[2];
	int rc, sirq_polarity;

	np = pdev->dev.of_node;

	vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL);
	if (!vuart)
		return -ENOMEM;

	vuart->dev = &pdev->dev;
	timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	memset(&port, 0, sizeof(port));
	port.port.private_data = vuart;
	port.port.mapbase = res->start;
	port.port.mapsize = resource_size(res);
	port.port.startup = aspeed_vuart_startup;
	port.port.shutdown = aspeed_vuart_shutdown;
	port.port.throttle = aspeed_vuart_throttle;
	port.port.unthrottle = aspeed_vuart_unthrottle;
	port.port.status = UPSTAT_SYNC_FIFO;
	port.port.dev = &pdev->dev;
	port.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
	port.bugs |= UART_BUG_TXRACE;

	rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
	if (rc < 0)
		return rc;

	if (of_property_read_u32(np, "clock-frequency", &clk)) {
		vuart->clk = devm_clk_get(&pdev->dev, NULL);
		if (IS_ERR(vuart->clk)) {
			dev_warn(&pdev->dev,
				"clk or clock-frequency not defined\n");
			rc = PTR_ERR(vuart->clk);
			goto err_sysfs_remove;
		}

		rc = clk_prepare_enable(vuart->clk);
		if (rc < 0)
			goto err_sysfs_remove;

		clk = clk_get_rate(vuart->clk);
	}

	/* If current-speed was set, then try not to change it. */
	if (of_property_read_u32(np, "current-speed", &prop) == 0)
		port.port.custom_divisor = clk / (16 * prop);

	/* Check for shifted address mapping */
	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
		port.port.mapbase += prop;

	/* Check for registers offset within the devices address range */
	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
		port.port.regshift = prop;

	/* Check for fifo size */
	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
		port.port.fifosize = prop;

	/* Check for a fixed line number */
	rc = of_alias_get_id(np, "serial");
	if (rc >= 0)
		port.port.line = rc;

	port.port.irq = irq_of_parse_and_map(np, 0);
	port.port.handle_irq = aspeed_vuart_handle_irq;
	port.port.iotype = UPIO_MEM;
	port.port.type = PORT_16550A;
	port.port.uartclk = clk;
	port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
		| UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST;

	if (of_property_read_bool(np, "no-loopback-test"))
		port.port.flags |= UPF_SKIP_TEST;

	if (port.port.fifosize)
		port.capabilities = UART_CAP_FIFO;

	if (of_property_read_bool(np, "auto-flow-control"))
		port.capabilities |= UART_CAP_AFE;

	rc = serial8250_register_8250_port(&port);
	if (rc < 0)
		goto err_clk_disable;

	vuart->line = rc;
	vuart->port = serial8250_get_port(vuart->line);

	rc = of_parse_phandle_with_fixed_args(
		np, "aspeed,sirq-polarity-sense", 2, 0,
		&sirq_polarity_sense_args);
	if (rc < 0) {
		dev_dbg(&pdev->dev,
			"aspeed,sirq-polarity-sense property not found\n");
	} else {
		aspeed_vuart_auto_configure_sirq_polarity(
			vuart, sirq_polarity_sense_args.np,
			sirq_polarity_sense_args.args[0],
			BIT(sirq_polarity_sense_args.args[1]));
		of_node_put(sirq_polarity_sense_args.np);
	}

	rc = of_property_read_u32(np, "aspeed,lpc-io-reg", &prop);
	if (rc < 0)
		prop = ASPEED_VUART_DEFAULT_LPC_ADDR;

	rc = aspeed_vuart_set_lpc_address(vuart, prop);
	if (rc < 0) {
		dev_err(&pdev->dev, "invalid value in aspeed,lpc-io-reg property\n");
		goto err_clk_disable;
	}

	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", sirq, 2);
	if (rc < 0) {
		sirq[0] = ASPEED_VUART_DEFAULT_SIRQ;
		sirq[1] = ASPEED_VUART_DEFAULT_SIRQ_POLARITY;
	}

	rc = aspeed_vuart_set_sirq(vuart, sirq[0]);
	if (rc < 0) {
		dev_err(&pdev->dev, "invalid sirq number in aspeed,lpc-interrupts property\n");
		goto err_clk_disable;
	}

	sirq_polarity = aspeed_vuart_map_irq_polarity(sirq[1]);
	if (sirq_polarity < 0) {
		dev_err(&pdev->dev, "invalid sirq polarity in aspeed,lpc-interrupts property\n");
		rc = sirq_polarity;
		goto err_clk_disable;
	}

	aspeed_vuart_set_sirq_polarity(vuart, sirq_polarity);

	aspeed_vuart_set_enabled(vuart, true);
	aspeed_vuart_set_host_tx_discard(vuart, true);
	platform_set_drvdata(pdev, vuart);

	return 0;

err_clk_disable:
	clk_disable_unprepare(vuart->clk);
	irq_dispose_mapping(port.port.irq);
err_sysfs_remove:
	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
	return rc;
}