diff options
Diffstat (limited to 'arch/mips/jz4740/reset.c')
| -rw-r--r-- | arch/mips/jz4740/reset.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/mips/jz4740/reset.c b/arch/mips/jz4740/reset.c new file mode 100644 index 000000000..b6c6343d2 --- /dev/null +++ b/arch/mips/jz4740/reset.c @@ -0,0 +1,118 @@ +/* + * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> + * + * 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. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/pm.h> + +#include <asm/reboot.h> + +#include <asm/mach-jz4740/base.h> +#include <asm/mach-jz4740/timer.h> + +#include "reset.h" +#include "clock.h" + +static void jz4740_halt(void) +{ + while (1) { + __asm__(".set push;\n" + ".set mips3;\n" + "wait;\n" + ".set pop;\n" + ); + } +} + +#define JZ_REG_WDT_DATA 0x00 +#define JZ_REG_WDT_COUNTER_ENABLE 0x04 +#define JZ_REG_WDT_COUNTER 0x08 +#define JZ_REG_WDT_CTRL 0x0c + +static void jz4740_restart(char *command) +{ + void __iomem *wdt_base = ioremap(JZ4740_WDT_BASE_ADDR, 0x0f); + + jz4740_timer_enable_watchdog(); + + writeb(0, wdt_base + JZ_REG_WDT_COUNTER_ENABLE); + + writew(0, wdt_base + JZ_REG_WDT_COUNTER); + writew(0, wdt_base + JZ_REG_WDT_DATA); + writew(BIT(2), wdt_base + JZ_REG_WDT_CTRL); + + writeb(1, wdt_base + JZ_REG_WDT_COUNTER_ENABLE); + jz4740_halt(); +} + +#define JZ_REG_RTC_CTRL 0x00 +#define JZ_REG_RTC_HIBERNATE 0x20 +#define JZ_REG_RTC_WAKEUP_FILTER 0x24 +#define JZ_REG_RTC_RESET_COUNTER 0x28 + +#define JZ_RTC_CTRL_WRDY BIT(7) +#define JZ_RTC_WAKEUP_FILTER_MASK 0x0000FFE0 +#define JZ_RTC_RESET_COUNTER_MASK 0x00000FE0 + +static inline void jz4740_rtc_wait_ready(void __iomem *rtc_base) +{ + uint32_t ctrl; + + do { + ctrl = readl(rtc_base + JZ_REG_RTC_CTRL); + } while (!(ctrl & JZ_RTC_CTRL_WRDY)); +} + +static void jz4740_power_off(void) +{ + void __iomem *rtc_base = ioremap(JZ4740_RTC_BASE_ADDR, 0x38); + unsigned long wakeup_filter_ticks; + unsigned long reset_counter_ticks; + + /* + * Set minimum wakeup pin assertion time: 100 ms. + * Range is 0 to 2 sec if RTC is clocked at 32 kHz. + */ + wakeup_filter_ticks = (100 * jz4740_clock_bdata.rtc_rate) / 1000; + if (wakeup_filter_ticks < JZ_RTC_WAKEUP_FILTER_MASK) + wakeup_filter_ticks &= JZ_RTC_WAKEUP_FILTER_MASK; + else + wakeup_filter_ticks = JZ_RTC_WAKEUP_FILTER_MASK; + jz4740_rtc_wait_ready(rtc_base); + writel(wakeup_filter_ticks, rtc_base + JZ_REG_RTC_WAKEUP_FILTER); + + /* + * Set reset pin low-level assertion time after wakeup: 60 ms. + * Range is 0 to 125 ms if RTC is clocked at 32 kHz. + */ + reset_counter_ticks = (60 * jz4740_clock_bdata.rtc_rate) / 1000; + if (reset_counter_ticks < JZ_RTC_RESET_COUNTER_MASK) + reset_counter_ticks &= JZ_RTC_RESET_COUNTER_MASK; + else + reset_counter_ticks = JZ_RTC_RESET_COUNTER_MASK; + jz4740_rtc_wait_ready(rtc_base); + writel(reset_counter_ticks, rtc_base + JZ_REG_RTC_RESET_COUNTER); + + jz4740_rtc_wait_ready(rtc_base); + writel(1, rtc_base + JZ_REG_RTC_HIBERNATE); + + jz4740_halt(); +} + +void jz4740_reset_init(void) +{ + _machine_restart = jz4740_restart; + _machine_halt = jz4740_halt; + pm_power_off = jz4740_power_off; +} |