3c7d9c81e1
There seems to be some problem with at-least the S3C2440 and bus traffic during an reset. It is unlikely, but still possible that the system will hang in such a way that the watchdog cannot get the system out of the state it is in. Change to making the code that calls the watchdog reset run from cached memory so that instruction fetches have quiesced before the watchdog fires. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
358 lines
8.4 KiB
C
358 lines
8.4 KiB
C
/* linux/arch/arm/plat-s3c24xx/cpu.c
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*
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* Copyright (c) 2004-2005 Simtec Electronics
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* http://www.simtec.co.uk/products/SWLINUX/
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* Ben Dooks <ben@simtec.co.uk>
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*
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* S3C24XX CPU Support
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/serial_core.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#include <asm/hardware.h>
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#include <asm/irq.h>
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#include <asm/io.h>
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#include <asm/delay.h>
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#include <asm/cacheflush.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#include <asm/arch/system-reset.h>
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#include <asm/arch/regs-gpio.h>
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#include <asm/plat-s3c/regs-serial.h>
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#include <asm/plat-s3c24xx/cpu.h>
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#include <asm/plat-s3c24xx/devs.h>
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#include <asm/plat-s3c24xx/clock.h>
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#include <asm/plat-s3c24xx/s3c2400.h>
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#include <asm/plat-s3c24xx/s3c2410.h>
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#include <asm/plat-s3c24xx/s3c2412.h>
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#include "s3c244x.h"
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#include <asm/plat-s3c24xx/s3c2440.h>
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#include <asm/plat-s3c24xx/s3c2442.h>
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#include <asm/plat-s3c24xx/s3c2443.h>
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struct cpu_table {
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unsigned long idcode;
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unsigned long idmask;
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void (*map_io)(struct map_desc *mach_desc, int size);
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void (*init_uarts)(struct s3c2410_uartcfg *cfg, int no);
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void (*init_clocks)(int xtal);
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int (*init)(void);
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const char *name;
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};
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/* table of supported CPUs */
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static const char name_s3c2400[] = "S3C2400";
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static const char name_s3c2410[] = "S3C2410";
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static const char name_s3c2412[] = "S3C2412";
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static const char name_s3c2440[] = "S3C2440";
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static const char name_s3c2442[] = "S3C2442";
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static const char name_s3c2443[] = "S3C2443";
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static const char name_s3c2410a[] = "S3C2410A";
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static const char name_s3c2440a[] = "S3C2440A";
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static struct cpu_table cpu_ids[] __initdata = {
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{
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.idcode = 0x32410000,
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.idmask = 0xffffffff,
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.map_io = s3c2410_map_io,
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.init_clocks = s3c2410_init_clocks,
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.init_uarts = s3c2410_init_uarts,
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.init = s3c2410_init,
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.name = name_s3c2410
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},
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{
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.idcode = 0x32410002,
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.idmask = 0xffffffff,
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.map_io = s3c2410_map_io,
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.init_clocks = s3c2410_init_clocks,
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.init_uarts = s3c2410_init_uarts,
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.init = s3c2410_init,
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.name = name_s3c2410a
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},
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{
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.idcode = 0x32440000,
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.idmask = 0xffffffff,
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.map_io = s3c244x_map_io,
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.init_clocks = s3c244x_init_clocks,
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.init_uarts = s3c244x_init_uarts,
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.init = s3c2440_init,
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.name = name_s3c2440
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},
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{
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.idcode = 0x32440001,
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.idmask = 0xffffffff,
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.map_io = s3c244x_map_io,
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.init_clocks = s3c244x_init_clocks,
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.init_uarts = s3c244x_init_uarts,
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.init = s3c2440_init,
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.name = name_s3c2440a
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},
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{
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.idcode = 0x32440aaa,
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.idmask = 0xffffffff,
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.map_io = s3c244x_map_io,
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.init_clocks = s3c244x_init_clocks,
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.init_uarts = s3c244x_init_uarts,
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.init = s3c2442_init,
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.name = name_s3c2442
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},
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{
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.idcode = 0x32412001,
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.idmask = 0xffffffff,
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.map_io = s3c2412_map_io,
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.init_clocks = s3c2412_init_clocks,
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.init_uarts = s3c2412_init_uarts,
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.init = s3c2412_init,
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.name = name_s3c2412,
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},
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{ /* a newer version of the s3c2412 */
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.idcode = 0x32412003,
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.idmask = 0xffffffff,
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.map_io = s3c2412_map_io,
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.init_clocks = s3c2412_init_clocks,
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.init_uarts = s3c2412_init_uarts,
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.init = s3c2412_init,
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.name = name_s3c2412,
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},
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{
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.idcode = 0x32443001,
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.idmask = 0xffffffff,
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.map_io = s3c2443_map_io,
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.init_clocks = s3c2443_init_clocks,
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.init_uarts = s3c2443_init_uarts,
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.init = s3c2443_init,
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.name = name_s3c2443,
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},
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{
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.idcode = 0x0, /* S3C2400 doesn't have an idcode */
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.idmask = 0xffffffff,
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.map_io = s3c2400_map_io,
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.init_clocks = s3c2400_init_clocks,
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.init_uarts = s3c2400_init_uarts,
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.init = s3c2400_init,
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.name = name_s3c2400
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},
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};
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/* minimal IO mapping */
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static struct map_desc s3c_iodesc[] __initdata = {
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IODESC_ENT(GPIO),
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IODESC_ENT(IRQ),
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IODESC_ENT(MEMCTRL),
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IODESC_ENT(UART)
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};
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static struct cpu_table *
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s3c_lookup_cpu(unsigned long idcode)
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{
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struct cpu_table *tab;
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int count;
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tab = cpu_ids;
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for (count = 0; count < ARRAY_SIZE(cpu_ids); count++, tab++) {
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if ((idcode & tab->idmask) == tab->idcode)
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return tab;
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}
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return NULL;
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}
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/* cpu information */
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static struct cpu_table *cpu;
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static unsigned long s3c24xx_read_idcode_v5(void)
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{
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#if defined(CONFIG_CPU_S3C2412) || defined(CONFIG_CPU_S3C2413)
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return __raw_readl(S3C2412_GSTATUS1);
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#else
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return 1UL; /* don't look like an 2400 */
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#endif
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}
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static unsigned long s3c24xx_read_idcode_v4(void)
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{
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#ifndef CONFIG_CPU_S3C2400
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return __raw_readl(S3C2410_GSTATUS1);
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#else
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return 0UL;
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#endif
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}
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/* Hook for arm_pm_restart to ensure we execute the reset code
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* with the caches enabled. It seems at least the S3C2440 has a problem
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* resetting if there is bus activity interrupted by the reset.
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*/
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static void s3c24xx_pm_restart(char mode)
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{
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if (mode != 's') {
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unsigned long flags;
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local_irq_save(flags);
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__cpuc_flush_kern_all();
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__cpuc_flush_user_all();
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arch_reset(mode);
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local_irq_restore(flags);
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}
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/* fallback, or unhandled */
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arm_machine_restart(mode);
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}
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void __init s3c24xx_init_io(struct map_desc *mach_desc, int size)
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{
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unsigned long idcode = 0x0;
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/* initialise the io descriptors we need for initialisation */
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iotable_init(s3c_iodesc, ARRAY_SIZE(s3c_iodesc));
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if (cpu_architecture() >= CPU_ARCH_ARMv5) {
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idcode = s3c24xx_read_idcode_v5();
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} else {
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idcode = s3c24xx_read_idcode_v4();
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}
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cpu = s3c_lookup_cpu(idcode);
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if (cpu == NULL) {
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printk(KERN_ERR "Unknown CPU type 0x%08lx\n", idcode);
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panic("Unknown S3C24XX CPU");
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}
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printk("CPU %s (id 0x%08lx)\n", cpu->name, idcode);
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if (cpu->map_io == NULL || cpu->init == NULL) {
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printk(KERN_ERR "CPU %s support not enabled\n", cpu->name);
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panic("Unsupported S3C24XX CPU");
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}
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arm_pm_restart = s3c24xx_pm_restart;
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(cpu->map_io)(mach_desc, size);
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}
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/* s3c24xx_init_clocks
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*
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* Initialise the clock subsystem and associated information from the
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* given master crystal value.
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*
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* xtal = 0 -> use default PLL crystal value (normally 12MHz)
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* != 0 -> PLL crystal value in Hz
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*/
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void __init s3c24xx_init_clocks(int xtal)
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{
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if (xtal == 0)
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xtal = 12*1000*1000;
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if (cpu == NULL)
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panic("s3c24xx_init_clocks: no cpu setup?\n");
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if (cpu->init_clocks == NULL)
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panic("s3c24xx_init_clocks: cpu has no clock init\n");
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else
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(cpu->init_clocks)(xtal);
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}
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/* uart management */
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static int nr_uarts __initdata = 0;
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static struct s3c2410_uartcfg uart_cfgs[3];
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/* s3c24xx_init_uartdevs
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*
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* copy the specified platform data and configuration into our central
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* set of devices, before the data is thrown away after the init process.
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*
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* This also fills in the array passed to the serial driver for the
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* early initialisation of the console.
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*/
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void __init s3c24xx_init_uartdevs(char *name,
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struct s3c24xx_uart_resources *res,
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struct s3c2410_uartcfg *cfg, int no)
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{
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struct platform_device *platdev;
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struct s3c2410_uartcfg *cfgptr = uart_cfgs;
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struct s3c24xx_uart_resources *resp;
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int uart;
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memcpy(cfgptr, cfg, sizeof(struct s3c2410_uartcfg) * no);
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for (uart = 0; uart < no; uart++, cfg++, cfgptr++) {
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platdev = s3c24xx_uart_src[cfgptr->hwport];
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resp = res + cfgptr->hwport;
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s3c24xx_uart_devs[uart] = platdev;
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platdev->name = name;
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platdev->resource = resp->resources;
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platdev->num_resources = resp->nr_resources;
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platdev->dev.platform_data = cfgptr;
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}
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nr_uarts = no;
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}
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void __init s3c24xx_init_uarts(struct s3c2410_uartcfg *cfg, int no)
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{
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if (cpu == NULL)
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return;
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if (cpu->init_uarts == NULL) {
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printk(KERN_ERR "s3c24xx_init_uarts: cpu has no uart init\n");
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} else
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(cpu->init_uarts)(cfg, no);
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}
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static int __init s3c_arch_init(void)
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{
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int ret;
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// do the correct init for cpu
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if (cpu == NULL)
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panic("s3c_arch_init: NULL cpu\n");
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ret = (cpu->init)();
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if (ret != 0)
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return ret;
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ret = platform_add_devices(s3c24xx_uart_devs, nr_uarts);
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return ret;
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}
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arch_initcall(s3c_arch_init);
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