From 7e92b4fc345f5b6f57585fbe5ffdb0f24d7c9b26 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 8 May 2007 00:36:07 -0700 Subject: [PATCH] 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 Cc: Keith Owens Cc: Len Brown Cc: Adam Belay Cc: Matthieu CASTET Cc: Jean Tourrilhes Cc: Matthew Garrett Cc: Ville Syrjala Cc: Russell King Cc: Samuel Ortiz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 5 +++ arch/i386/kernel/Makefile | 1 + arch/i386/kernel/legacy_serial.c | 67 +++++++++++++++++++++++++++++ arch/x86_64/kernel/Makefile | 2 + drivers/serial/Kconfig | 14 +++--- include/asm-i386/serial.h | 16 ------- include/asm-x86_64/serial.h | 16 ------- 7 files changed, 84 insertions(+), 37 deletions(-) create mode 100644 arch/i386/kernel/legacy_serial.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index fa885174fd7..bebebe4fd46 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -816,6 +816,11 @@ and is between 256 and 4096 characters. It is defined in the file lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip Format: addr:,irq: + legacy_serial.force [HW,IA-32,X86-64] + Probe for COM ports at legacy addresses even + if PNPBIOS or ACPI should describe them. This + is for working around firmware defects. + llsc*= [IA64] See function print_params() in arch/ia64/sn/kernel/llsc4.c. 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 + * + * 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 +#include +#include +#include + +/* 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"); diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index 4d94c51803d..de1de8a2fd8 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_IOMMU) += pci-gart.o aperture.o obj-$(CONFIG_CALGARY_IOMMU) += pci-calgary.o tce.o obj-$(CONFIG_SWIOTLB) += pci-swiotlb.o +obj-$(CONFIG_SERIAL_8250) += legacy_serial.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_X86_PM_TIMER) += pmtimer.o obj-$(CONFIG_X86_VSMP) += vsmp.o @@ -49,6 +50,7 @@ CFLAGS_vsyscall.o := $(PROFILING) -g0 therm_throt-y += ../../i386/kernel/cpu/mcheck/therm_throt.o bootflag-y += ../../i386/kernel/bootflag.o +legacy_serial-y += ../../i386/kernel/legacy_serial.o cpuid-$(subst m,y,$(CONFIG_X86_CPUID)) += ../../i386/kernel/cpuid.o topology-y += ../../i386/kernel/topology.o microcode-$(subst m,y,$(CONFIG_MICROCODE)) += ../../i386/kernel/microcode.o diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 924e9bd757f..e8efe938c4e 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -73,17 +73,21 @@ config SERIAL_8250_PCI depends on SERIAL_8250 && PCI default SERIAL_8250 help - This builds standard PCI serial support. You may be able to - disable this feature if you only need legacy serial support. - Saves about 9K. + Say Y here if you have PCI serial ports. + + To compile this driver as a module, choose M here: the module + will be called 8250_pci. config SERIAL_8250_PNP tristate "8250/16550 PNP device support" if EMBEDDED depends on SERIAL_8250 && PNP default SERIAL_8250 help - This builds standard PNP serial support. You may be able to - disable this feature if you only need legacy serial support. + Say Y here if you have serial ports described by PNPBIOS or ACPI. + These are typically ports built into the system board. + + To compile this driver as a module, choose M here: the module + will be called 8250_pnp. config SERIAL_8250_HP300 tristate diff --git a/include/asm-i386/serial.h b/include/asm-i386/serial.h index bd67480ca10..57a4306cdf6 100644 --- a/include/asm-i386/serial.h +++ b/include/asm-i386/serial.h @@ -11,19 +11,3 @@ * megabits/second; but this requires the faster clock. */ #define BASE_BAUD ( 1843200 / 16 ) - -/* Standard COM flags (except for COM4, because of the 8514 problem) */ -#ifdef CONFIG_SERIAL_DETECT_IRQ -#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ) -#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_AUTO_IRQ) -#else -#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) -#define STD_COM4_FLAGS ASYNC_BOOT_AUTOCONF -#endif - -#define SERIAL_PORT_DFNS \ - /* UART CLK PORT IRQ FLAGS */ \ - { 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS }, /* ttyS0 */ \ - { 0, BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS }, /* ttyS1 */ \ - { 0, BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS }, /* ttyS2 */ \ - { 0, BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS }, /* ttyS3 */ diff --git a/include/asm-x86_64/serial.h b/include/asm-x86_64/serial.h index b0496e0d72a..8ebd765c674 100644 --- a/include/asm-x86_64/serial.h +++ b/include/asm-x86_64/serial.h @@ -11,19 +11,3 @@ * megabits/second; but this requires the faster clock. */ #define BASE_BAUD ( 1843200 / 16 ) - -/* Standard COM flags (except for COM4, because of the 8514 problem) */ -#ifdef CONFIG_SERIAL_DETECT_IRQ -#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ) -#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_AUTO_IRQ) -#else -#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) -#define STD_COM4_FLAGS ASYNC_BOOT_AUTOCONF -#endif - -#define SERIAL_PORT_DFNS \ - /* UART CLK PORT IRQ FLAGS */ \ - { 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS }, /* ttyS0 */ \ - { 0, BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS }, /* ttyS1 */ \ - { 0, BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS }, /* ttyS2 */ \ - { 0, BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS }, /* ttyS3 */ -- 2.41.1