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authorBjorn Helgaas <bjorn.helgaas@hp.com>2007-05-08 00:36:07 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-08 11:15:23 -0700
commit7e92b4fc345f5b6f57585fbe5ffdb0f24d7c9b26 (patch)
treea8e9dac38a9c8dd22bd182c13e2ae0e6d32bd729 /arch/i386/kernel
parentd0d4f69bb65a8c1c1430c577a583632709b874c6 (diff)
x86, serial: convert legacy COM ports to platform devices
Make x86 COM ports into platform devices and don't probe for them if we have PNP. This prevents double discovery, where a device was found both by the legacy probe and by 8250_pnp, e.g., serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A 00:02: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A This also means IRDA devices without a UART PNP ID will no longer be claimed by the serial driver, which might require changes in IRDA drivers and administration. In addition to this patch, you may need to configure a setserial init script, e.g., /etc/init.d/setserial, so it doesn't poke legacy UART stuff back in. On Debian, "dpkg-reconfigure setserial" with the "kernel" option does this. To force the old legacy probe behavior even when we have PNPBIOS or ACPI, load the new legacy_serial module (or build 8250 static) with the "legacy_serial.force" option. [akpm@linux-foundation.org: fix makefiles] Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Keith Owens <kaos@ocs.com.au> Cc: Len Brown <lenb@kernel.org> Cc: Adam Belay <ambx1@neo.rr.com> Cc: Matthieu CASTET <castet.matthieu@free.fr> Cc: Jean Tourrilhes <jt@hpl.hp.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Ville Syrjala <syrjala@sci.fi> Cc: Russell King <rmk+serial@arm.linux.org.uk> Cc: Samuel Ortiz <samuel@sortiz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/i386/kernel')
-rw-r--r--arch/i386/kernel/Makefile1
-rw-r--r--arch/i386/kernel/legacy_serial.c67
2 files changed, 68 insertions, 0 deletions
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 4f98516b9f9..91cff8dc9e1 100644
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -34,6 +34,7 @@ obj-y += sysenter.o vsyscall.o
obj-$(CONFIG_ACPI_SRAT) += srat.o
obj-$(CONFIG_EFI) += efi.o efi_stub.o
obj-$(CONFIG_DOUBLEFAULT) += doublefault.o
+obj-$(CONFIG_SERIAL_8250) += legacy_serial.o
obj-$(CONFIG_VM86) += vm86.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_HPET_TIMER) += hpet.o
diff --git a/arch/i386/kernel/legacy_serial.c b/arch/i386/kernel/legacy_serial.c
new file mode 100644
index 00000000000..21510118544
--- /dev/null
+++ b/arch/i386/kernel/legacy_serial.c
@@ -0,0 +1,67 @@
+/*
+ * Legacy COM port devices for x86 platforms without PNPBIOS or ACPI.
+ * Data taken from include/asm-i386/serial.h.
+ *
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ * Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pnp.h>
+#include <linux/serial_8250.h>
+
+/* Standard COM flags (except for COM4, because of the 8514 problem) */
+#ifdef CONFIG_SERIAL_DETECT_IRQ
+#define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_AUTO_IRQ)
+#define COM4_FLAGS (UPF_BOOT_AUTOCONF | UPF_AUTO_IRQ)
+#else
+#define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST)
+#define COM4_FLAGS UPF_BOOT_AUTOCONF
+#endif
+
+#define PORT(_base,_irq,_flags) \
+ { \
+ .iobase = _base, \
+ .irq = _irq, \
+ .uartclk = 1843200, \
+ .iotype = UPIO_PORT, \
+ .flags = _flags, \
+ }
+
+static struct plat_serial8250_port x86_com_data[] = {
+ PORT(0x3F8, 4, COM_FLAGS),
+ PORT(0x2F8, 3, COM_FLAGS),
+ PORT(0x3E8, 4, COM_FLAGS),
+ PORT(0x2E8, 3, COM4_FLAGS),
+ { },
+};
+
+static struct platform_device x86_com_device = {
+ .name = "serial8250",
+ .id = PLAT8250_DEV_PLATFORM,
+ .dev = {
+ .platform_data = x86_com_data,
+ },
+};
+
+static int force_legacy_probe;
+module_param_named(force, force_legacy_probe, bool, 0);
+MODULE_PARM_DESC(force, "Force legacy serial port probe");
+
+static int __init serial8250_x86_com_init(void)
+{
+ if (pnp_platform_devices && !force_legacy_probe)
+ return -ENODEV;
+
+ return platform_device_register(&x86_com_device);
+}
+
+module_init(serial8250_x86_com_init);
+
+MODULE_AUTHOR("Bjorn Helgaas");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic 8250/16x50 legacy probe module");