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path: root/drivers/tty/serial/8250
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-rw-r--r--drivers/tty/serial/8250/8250_core.c7
-rw-r--r--drivers/tty/serial/8250/8250_early.c29
-rw-r--r--drivers/tty/serial/8250/8250_ingenic.c2
-rw-r--r--drivers/tty/serial/8250/8250_mtk.c35
-rw-r--r--drivers/tty/serial/8250/8250_of.c347
-rw-r--r--drivers/tty/serial/8250/8250_port.c20
-rw-r--r--drivers/tty/serial/8250/8250_uniphier.c24
-rw-r--r--drivers/tty/serial/8250/Kconfig14
-rw-r--r--drivers/tty/serial/8250/Makefile1
9 files changed, 425 insertions, 54 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 58dbff93a..279a842cd 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -620,7 +620,7 @@ static int univ8250_console_setup(struct console *co, char *options)
* @options: ptr to option string from console command line
*
* Only attempts to match console command lines of the form:
- * console=uart[8250],io|mmio|mmio32,<addr>[,<options>]
+ * console=uart[8250],io|mmio|mmio16|mmio32,<addr>[,<options>]
* console=uart[8250],0x<addr>[,<options>]
* This form is used to register an initial earlycon boot console and
* replace it with the serial8250_console at 8250 driver init.
@@ -650,8 +650,9 @@ static int univ8250_console_match(struct console *co, char *name, int idx,
if (port->iotype != iotype)
continue;
- if ((iotype == UPIO_MEM || iotype == UPIO_MEM32) &&
- (port->mapbase != addr))
+ if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 ||
+ iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE)
+ && (port->mapbase != addr))
continue;
if (iotype == UPIO_PORT && port->iobase != addr)
continue;
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index e2919b4d1..2aa151366 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -42,6 +42,8 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse
switch (port->iotype) {
case UPIO_MEM:
return readb(port->membase + offset);
+ case UPIO_MEM16:
+ return readw(port->membase + (offset << 1));
case UPIO_MEM32:
return readl(port->membase + (offset << 2));
case UPIO_MEM32BE:
@@ -59,6 +61,9 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int
case UPIO_MEM:
writeb(value, port->membase + offset);
break;
+ case UPIO_MEM16:
+ writew(value, port->membase + (offset << 1));
+ break;
case UPIO_MEM32:
writel(value, port->membase + (offset << 2));
break;
@@ -73,43 +78,27 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int
#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
-static void __init wait_for_xmitr(struct uart_port *port)
+static void __init serial_putc(struct uart_port *port, int c)
{
unsigned int status;
+ serial8250_early_out(port, UART_TX, c);
+
for (;;) {
status = serial8250_early_in(port, UART_LSR);
if ((status & BOTH_EMPTY) == BOTH_EMPTY)
- return;
+ break;
cpu_relax();
}
}
-static void __init serial_putc(struct uart_port *port, int c)
-{
- wait_for_xmitr(port);
- serial8250_early_out(port, UART_TX, c);
-}
-
static void __init early_serial8250_write(struct console *console,
const char *s, unsigned int count, unsigned int loglevel)
{
struct earlycon_device *device = console->data;
struct uart_port *port = &device->port;
- unsigned int ier;
-
- /* Save the IER and disable interrupts preserving the UUE bit */
- ier = serial8250_early_in(port, UART_IER);
- if (ier)
- serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
uart_console_write(port, s, count, serial_putc);
-
- /* Wait for transmitter to become empty and restore the IER */
- wait_for_xmitr(port);
-
- if (ier)
- serial8250_early_out(port, UART_IER, ier);
}
static void __init init_port(struct earlycon_device *device)
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 49394b4c5..d6e1ec9b4 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -48,6 +48,7 @@ static const struct of_device_id of_match[];
#define UART_MCR_MDCE BIT(7)
#define UART_MCR_FCM BIT(6)
+#ifdef CONFIG_SERIAL_EARLYCON
static struct earlycon_device *early_device;
static uint8_t __init early_in(struct uart_port *port, int offset)
@@ -140,6 +141,7 @@ OF_EARLYCON_DECLARE(jz4775_uart, "ingenic,jz4775-uart",
EARLYCON_DECLARE(jz4780_uart, ingenic_early_console_setup);
OF_EARLYCON_DECLARE(jz4780_uart, "ingenic,jz4780-uart",
ingenic_early_console_setup);
+#endif /* CONFIG_SERIAL_EARLYCON */
static void ingenic_uart_serial_out(struct uart_port *p, int offset, int value)
{
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 78883ca64..0e590b233 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -16,7 +16,7 @@
*/
#include <linux/clk.h>
#include <linux/io.h>
-#include <linux/module.h>
+#include <linux/init.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
@@ -245,23 +245,6 @@ static int mtk8250_probe(struct platform_device *pdev)
return 0;
}
-static int mtk8250_remove(struct platform_device *pdev)
-{
- struct mtk8250_data *data = platform_get_drvdata(pdev);
-
- pm_runtime_get_sync(&pdev->dev);
-
- serial8250_unregister_port(data->line);
-
- pm_runtime_disable(&pdev->dev);
- pm_runtime_put_noidle(&pdev->dev);
-
- if (!pm_runtime_status_suspended(&pdev->dev))
- mtk8250_runtime_suspend(&pdev->dev);
-
- return 0;
-}
-
#ifdef CONFIG_PM_SLEEP
static int mtk8250_suspend(struct device *dev)
{
@@ -292,18 +275,18 @@ static const struct of_device_id mtk8250_of_match[] = {
{ .compatible = "mediatek,mt6577-uart" },
{ /* Sentinel */ }
};
-MODULE_DEVICE_TABLE(of, mtk8250_of_match);
static struct platform_driver mtk8250_platform_driver = {
.driver = {
- .name = "mt6577-uart",
- .pm = &mtk8250_pm_ops,
- .of_match_table = mtk8250_of_match,
+ .name = "mt6577-uart",
+ .pm = &mtk8250_pm_ops,
+ .of_match_table = mtk8250_of_match,
+ .suppress_bind_attrs = true,
+
},
.probe = mtk8250_probe,
- .remove = mtk8250_remove,
};
-module_platform_driver(mtk8250_platform_driver);
+builtin_platform_driver(mtk8250_platform_driver);
#ifdef CONFIG_SERIAL_8250_CONSOLE
static int __init early_mtk8250_setup(struct earlycon_device *device,
@@ -319,7 +302,3 @@ static int __init early_mtk8250_setup(struct earlycon_device *device,
OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
#endif
-
-MODULE_AUTHOR("Matthias Brugger");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Mediatek 8250 serial port driver");
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
new file mode 100644
index 000000000..33021c1f7
--- /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");
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 5a85bbaa2..83aed6193 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -368,6 +368,18 @@ static void mem_serial_out(struct uart_port *p, int offset, int value)
writeb(value, p->membase + offset);
}
+static void mem16_serial_out(struct uart_port *p, int offset, int value)
+{
+ offset = offset << p->regshift;
+ writew(value, p->membase + offset);
+}
+
+static unsigned int mem16_serial_in(struct uart_port *p, int offset)
+{
+ offset = offset << p->regshift;
+ return readw(p->membase + offset);
+}
+
static void mem32_serial_out(struct uart_port *p, int offset, int value)
{
offset = offset << p->regshift;
@@ -425,6 +437,11 @@ static void set_io_from_upio(struct uart_port *p)
p->serial_out = mem_serial_out;
break;
+ case UPIO_MEM16:
+ p->serial_in = mem16_serial_in;
+ p->serial_out = mem16_serial_out;
+ break;
+
case UPIO_MEM32:
p->serial_in = mem32_serial_in;
p->serial_out = mem32_serial_out;
@@ -459,6 +476,7 @@ serial_port_out_sync(struct uart_port *p, int offset, int value)
{
switch (p->iotype) {
case UPIO_MEM:
+ case UPIO_MEM16:
case UPIO_MEM32:
case UPIO_MEM32BE:
case UPIO_AU:
@@ -2462,6 +2480,7 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
case UPIO_TSI:
case UPIO_MEM32:
case UPIO_MEM32BE:
+ case UPIO_MEM16:
case UPIO_MEM:
if (!port->mapbase)
break;
@@ -2499,6 +2518,7 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
case UPIO_TSI:
case UPIO_MEM32:
case UPIO_MEM32BE:
+ case UPIO_MEM16:
case UPIO_MEM:
if (!port->mapbase)
break;
diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c
index 245edbb68..bab6b3ae2 100644
--- a/drivers/tty/serial/8250/8250_uniphier.c
+++ b/drivers/tty/serial/8250/8250_uniphier.c
@@ -13,6 +13,7 @@
*/
#include <linux/clk.h>
+#include <linux/console.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -34,6 +35,29 @@ struct uniphier8250_priv {
spinlock_t atomic_write_lock;
};
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static int __init uniphier_early_console_setup(struct earlycon_device *device,
+ const char *options)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ /* This hardware always expects MMIO32 register interface. */
+ device->port.iotype = UPIO_MEM32;
+ device->port.regshift = 2;
+
+ /*
+ * Do not touch the divisor register in early_serial8250_setup();
+ * we assume it has been initialized by a boot loader.
+ */
+ device->baud = 0;
+
+ return early_serial8250_setup(device, options);
+}
+OF_EARLYCON_DECLARE(uniphier, "socionext,uniphier-uart",
+ uniphier_early_console_setup);
+#endif
+
/*
* The register map is slightly different from that of 8250.
* IO callbacks must be overridden for correct access to FCR, LCR, and MCR.
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 6412f1455..b03cb5175 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -361,9 +361,8 @@ config SERIAL_8250_UNIPHIER
config SERIAL_8250_INGENIC
bool "Support for Ingenic SoC serial ports"
- depends on SERIAL_8250_CONSOLE && OF_FLATTREE
+ depends on OF_FLATTREE
select LIBFDT
- select SERIAL_EARLYCON
help
If you have a system using an Ingenic SoC and wish to make use of
its UARTs, say Y to this option. If unsure, say N.
@@ -372,9 +371,18 @@ config SERIAL_8250_MID
tristate "Support for serial ports on Intel MID platforms"
depends on SERIAL_8250 && PCI
select HSU_DMA if SERIAL_8250_DMA
- select HSU_DMA_PCI if X86_INTEL_MID
+ select HSU_DMA_PCI if (HSU_DMA && X86_INTEL_MID)
select RATIONAL
help
Selecting this option will enable handling of the extra features
present on the UART found on Intel Medfield SOC and various other
Intel platforms.
+
+config SERIAL_OF_PLATFORM
+ tristate "Devicetree based probing for 8250 ports"
+ depends on SERIAL_8250 && OF
+ help
+ This option is used for all 8250 compatible serial ports that
+ are probed through devicetree, including Open Firmware based
+ PowerPC systems and embedded systems on architectures using the
+ flattened device tree format.
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index e177f8681..b9b9bca5b 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -28,5 +28,6 @@ obj-$(CONFIG_SERIAL_8250_MT6577) += 8250_mtk.o
obj-$(CONFIG_SERIAL_8250_UNIPHIER) += 8250_uniphier.o
obj-$(CONFIG_SERIAL_8250_INGENIC) += 8250_ingenic.o
obj-$(CONFIG_SERIAL_8250_MID) += 8250_mid.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM) += 8250_of.o
CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt