linux/arch/mips/mti-malta/malta-platform.c
Maciej W. Rozycki 636221b86c MIPS: Malta: Remove RTC Data Mode bootstrap breakage
YAMON requires and enforces the RTC Data Mode (Register B, DM bit) to
binary, that is the bit is set every time the board goes through the
firmware bootstrap sequence.  Likewise its calendar manipulation commands
interpret or set the RTC registers unconditionally as binary, never
actually checking what the value of the DM bit is, under the (correct)
assumption that it has been previously set, to indicate the binary mode.

 A change to Linux a while ago however introduced a platform-specific
tweak that clears that bit and therefore forces the data mode to BCD.
This causes clock corruption and misinterpretation that has to be fixed up
by user-mode tools in system startup scripts as the initial clock is often
incorrect according to the BCD interpretation forced.

 This change removes the hack; a comment included refers to alarm code,
but even if it was broken at one point by requiring the BCD mode, it
should have been trivially corrected and even if not, given how rarely the
alarm feature is used, that was not really a reasonable justification to
break the system clock that is indeed used by virtually everything.  And
either way the alarm code has been since fixed anyway.

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4336/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-09-14 17:54:33 +02:00

145 lines
3.3 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2006, 07 MIPS Technologies, Inc.
* written by Ralf Baechle (ralf@linux-mips.org)
* written by Ralf Baechle <ralf@linux-mips.org>
*
* Copyright (C) 2008 Wind River Systems, Inc.
* updated by Tiejun Chen <tiejun.chen@windriver.com>
*
* 1. Probe driver for the Malta's UART ports:
*
* o 2 ports in the SMC SuperIO
* o 1 port in the CBUS UART, a discrete 16550 which normally is only used
* for bringups.
*
* We don't use 8250_platform.c on Malta as it would result in the CBUS
* UART becoming ttyS0.
*
* 2. Register RTC-CMOS platform device on Malta.
*/
#include <linux/init.h>
#include <linux/serial_8250.h>
#include <linux/mc146818rtc.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/physmap.h>
#include <linux/platform_device.h>
#include <mtd/mtd-abi.h>
#define SMC_PORT(base, int) \
{ \
.iobase = base, \
.irq = int, \
.uartclk = 1843200, \
.iotype = UPIO_PORT, \
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST, \
.regshift = 0, \
}
#define CBUS_UART_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_IOREMAP)
static struct plat_serial8250_port uart8250_data[] = {
SMC_PORT(0x3F8, 4),
SMC_PORT(0x2F8, 3),
{
.mapbase = 0x1f000900, /* The CBUS UART */
.irq = MIPS_CPU_IRQ_BASE + 2,
.uartclk = 3686400, /* Twice the usual clk! */
.iotype = UPIO_MEM32,
.flags = CBUS_UART_FLAGS,
.regshift = 3,
},
{ },
};
static struct platform_device malta_uart8250_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = uart8250_data,
},
};
struct resource malta_rtc_resources[] = {
{
.start = RTC_PORT(0),
.end = RTC_PORT(7),
.flags = IORESOURCE_IO,
}, {
.start = RTC_IRQ,
.end = RTC_IRQ,
.flags = IORESOURCE_IRQ,
}
};
static struct platform_device malta_rtc_device = {
.name = "rtc_cmos",
.id = -1,
.resource = malta_rtc_resources,
.num_resources = ARRAY_SIZE(malta_rtc_resources),
};
static struct mtd_partition malta_mtd_partitions[] = {
{
.name = "YAMON",
.offset = 0x0,
.size = 0x100000,
.mask_flags = MTD_WRITEABLE
}, {
.name = "User FS",
.offset = 0x100000,
.size = 0x2e0000
}, {
.name = "Board Config",
.offset = 0x3e0000,
.size = 0x020000,
.mask_flags = MTD_WRITEABLE
}
};
static struct physmap_flash_data malta_flash_data = {
.width = 4,
.nr_parts = ARRAY_SIZE(malta_mtd_partitions),
.parts = malta_mtd_partitions
};
static struct resource malta_flash_resource = {
.start = 0x1e000000,
.end = 0x1e3fffff,
.flags = IORESOURCE_MEM
};
static struct platform_device malta_flash_device = {
.name = "physmap-flash",
.id = 0,
.dev = {
.platform_data = &malta_flash_data,
},
.num_resources = 1,
.resource = &malta_flash_resource,
};
static struct platform_device *malta_devices[] __initdata = {
&malta_uart8250_device,
&malta_rtc_device,
&malta_flash_device,
};
static int __init malta_add_devices(void)
{
int err;
err = platform_add_devices(malta_devices, ARRAY_SIZE(malta_devices));
if (err)
return err;
return 0;
}
device_initcall(malta_add_devices);