1 files changed, 347 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
new file mode 100644
index 000000000000..33021c1f7d55
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -0,0 +1,347 @@
+/*
+ *  Serial Port driver for Open Firmware platform devices
+ *
+ *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ *
+ *  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.
+ *
+ */
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+struct of_serial_info {
+	struct clk *clk;
+	int type;
+	int line;
+};
+
+#ifdef CONFIG_ARCH_TEGRA
+void tegra_serial_handle_break(struct uart_port *p)
+{
+	unsigned int status, tmout = 10000;
+
+	do {
+		status = p->serial_in(p, UART_LSR);
+		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
+			status = p->serial_in(p, UART_RX);
+		else
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (1);
+}
+#else
+static inline void tegra_serial_handle_break(struct uart_port *port)
+{
+}
+#endif
+
+/*
+ * Fill a struct uart_port for a given device node
+ */
+static int of_platform_serial_setup(struct platform_device *ofdev,
+			int type, struct uart_port *port,
+			struct of_serial_info *info)
+{
+	struct resource resource;
+	struct device_node *np = ofdev->dev.of_node;
+	u32 clk, spd, prop;
+	int ret;
+
+	memset(port, 0, sizeof *port);
+	if (of_property_read_u32(np, "clock-frequency", &clk)) {
+
+		/* Get clk rate through clk driver if present */
+		info->clk = devm_clk_get(&ofdev->dev, NULL);
+		if (IS_ERR(info->clk)) {
+			dev_warn(&ofdev->dev,
+				"clk or clock-frequency not defined\n");
+			return PTR_ERR(info->clk);
+		}
+
+		ret = clk_prepare_enable(info->clk);
+		if (ret < 0)
+			return ret;
+
+		clk = clk_get_rate(info->clk);
+	}
+	/* If current-speed was set, then try not to change it. */
+	if (of_property_read_u32(np, "current-speed", &spd) == 0)
+		port->custom_divisor = clk / (16 * spd);
+
+	ret = of_address_to_resource(np, 0, &resource);
+	if (ret) {
+		dev_warn(&ofdev->dev, "invalid address\n");
+		goto out;
+	}
+
+	spin_lock_init(&port->lock);
+	port->mapbase = resource.start;
+	port->mapsize = resource_size(&resource);
+
+	/* Check for shifted address mapping */
+	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
+		port->mapbase += prop;
+
+	/* Check for registers offset within the devices address range */
+	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
+		port->regshift = prop;
+
+	/* Check for fifo size */
+	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
+		port->fifosize = prop;
+
+	/* Check for a fixed line number */
+	ret = of_alias_get_id(np, "serial");
+	if (ret >= 0)
+		port->line = ret;
+
+	port->irq = irq_of_parse_and_map(np, 0);
+	port->iotype = UPIO_MEM;
+	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+		switch (prop) {
+		case 1:
+			port->iotype = UPIO_MEM;
+			break;
+		case 2:
+			port->iotype = UPIO_MEM16;
+			break;
+		case 4:
+			port->iotype = of_device_is_big_endian(np) ?
+				       UPIO_MEM32BE : UPIO_MEM32;
+			break;
+		default:
+			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
+				 prop);
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+	port->type = type;
+	port->uartclk = clk;
+	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
+		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
+
+	if (of_find_property(np, "no-loopback-test", NULL))
+		port->flags |= UPF_SKIP_TEST;
+
+	port->dev = &ofdev->dev;
+
+	switch (type) {
+	case PORT_TEGRA:
+		port->handle_break = tegra_serial_handle_break;
+		break;
+
+	case PORT_RT2880:
+		port->iotype = UPIO_AU;
+		break;
+	}
+
+	if (IS_ENABLED(CONFIG_SERIAL_8250_FSL) &&
+	    (of_device_is_compatible(np, "fsl,ns16550") ||
+	     of_device_is_compatible(np, "fsl,16550-FIFO64")))
+		port->handle_irq = fsl8250_handle_irq;
+
+	return 0;
+out:
+	if (info->clk)
+		clk_disable_unprepare(info->clk);
+	return ret;
+}
+
+/*
+ * Try to register a serial port
+ */
+static const struct of_device_id of_platform_serial_table[];
+static int of_platform_serial_probe(struct platform_device *ofdev)
+{
+	const struct of_device_id *match;
+	struct of_serial_info *info;
+	struct uart_port port;
+	int port_type;
+	int ret;
+
+	match = of_match_device(of_platform_serial_table, &ofdev->dev);
+	if (!match)
+		return -EINVAL;
+
+	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
+		return -EBUSY;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info == NULL)
+		return -ENOMEM;
+
+	port_type = (unsigned long)match->data;
+	ret = of_platform_serial_setup(ofdev, port_type, &port, info);
+	if (ret)
+		goto out;
+
+	switch (port_type) {
+	case PORT_8250 ... PORT_MAX_8250:
+	{
+		struct uart_8250_port port8250;
+		memset(&port8250, 0, sizeof(port8250));
+		port8250.port = port;
+
+		if (port.fifosize)
+			port8250.capabilities = UART_CAP_FIFO;
+
+		if (of_property_read_bool(ofdev->dev.of_node,
+					  "auto-flow-control"))
+			port8250.capabilities |= UART_CAP_AFE;
+
+		ret = serial8250_register_8250_port(&port8250);
+		break;
+	}
+	default:
+		/* need to add code for these */
+	case PORT_UNKNOWN:
+		dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
+		ret = -ENODEV;
+		break;
+	}
+	if (ret < 0)
+		goto out;
+
+	info->type = port_type;
+	info->line = ret;
+	platform_set_drvdata(ofdev, info);
+	return 0;
+out:
+	kfree(info);
+	irq_dispose_mapping(port.irq);
+	return ret;
+}
+
+/*
+ * Release a line
+ */
+static int of_platform_serial_remove(struct platform_device *ofdev)
+{
+	struct of_serial_info *info = platform_get_drvdata(ofdev);
+	switch (info->type) {
+	case PORT_8250 ... PORT_MAX_8250:
+		serial8250_unregister_port(info->line);
+		break;
+	default:
+		/* need to add code for these */
+		break;
+	}
+
+	if (info->clk)
+		clk_disable_unprepare(info->clk);
+	kfree(info);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void of_serial_suspend_8250(struct of_serial_info *info)
+{
+	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+	struct uart_port *port = &port8250->port;
+
+	serial8250_suspend_port(info->line);
+	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+		clk_disable_unprepare(info->clk);
+}
+
+static void of_serial_resume_8250(struct of_serial_info *info)
+{
+	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+	struct uart_port *port = &port8250->port;
+
+	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+		clk_prepare_enable(info->clk);
+
+	serial8250_resume_port(info->line);
+}
+
+static int of_serial_suspend(struct device *dev)
+{
+	struct of_serial_info *info = dev_get_drvdata(dev);
+
+	switch (info->type) {
+	case PORT_8250 ... PORT_MAX_8250:
+		of_serial_suspend_8250(info);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int of_serial_resume(struct device *dev)
+{
+	struct of_serial_info *info = dev_get_drvdata(dev);
+
+	switch (info->type) {
+	case PORT_8250 ... PORT_MAX_8250:
+		of_serial_resume_8250(info);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);
+
+/*
+ * A few common types, add more as needed.
+ */
+static const struct of_device_id of_platform_serial_table[] = {
+	{ .compatible = "ns8250",   .data = (void *)PORT_8250, },
+	{ .compatible = "ns16450",  .data = (void *)PORT_16450, },
+	{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
+	{ .compatible = "ns16550",  .data = (void *)PORT_16550, },
+	{ .compatible = "ns16750",  .data = (void *)PORT_16750, },
+	{ .compatible = "ns16850",  .data = (void *)PORT_16850, },
+	{ .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
+	{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
+	{ .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, },
+	{ .compatible = "altr,16550-FIFO32",
+		.data = (void *)PORT_ALTR_16550_F32, },
+	{ .compatible = "altr,16550-FIFO64",
+		.data = (void *)PORT_ALTR_16550_F64, },
+	{ .compatible = "altr,16550-FIFO128",
+		.data = (void *)PORT_ALTR_16550_F128, },
+	{ .compatible = "mrvl,mmp-uart",
+		.data = (void *)PORT_XSCALE, },
+	{ .compatible = "mrvl,pxa-uart",
+		.data = (void *)PORT_XSCALE, },
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, of_platform_serial_table);
+
+static struct platform_driver of_platform_serial_driver = {
+	.driver = {
+		.name = "of_serial",
+		.of_match_table = of_platform_serial_table,
+	},
+	.probe = of_platform_serial_probe,
+	.remove = of_platform_serial_remove,
+};
+
+module_platform_driver(of_platform_serial_driver);
+
+MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");