diff options
Diffstat (limited to 'drivers/watchdog/tnetv107x_wdt.c')
| -rw-r--r-- | drivers/watchdog/tnetv107x_wdt.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/watchdog/tnetv107x_wdt.c b/drivers/watchdog/tnetv107x_wdt.c new file mode 100644 index 0000000000..18aadb0c65 --- /dev/null +++ b/drivers/watchdog/tnetv107x_wdt.c @@ -0,0 +1,180 @@ +/* + * TNETV107X: Watchdog timer implementation (for reset) + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * 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 <common.h> +#include <asm/io.h> +#include <asm/arch/clock.h> + +#define MAX_DIV 0xFFFE0001 + +struct wdt_regs { + u32 kick_lock; +#define KICK_LOCK_1 0x5555 +#define KICK_LOCK_2 0xaaaa + u32 kick; + + u32 change_lock; +#define CHANGE_LOCK_1 0x6666 +#define CHANGE_LOCK_2 0xbbbb + u32 change; + + u32 disable_lock; +#define DISABLE_LOCK_1 0x7777 +#define DISABLE_LOCK_2 0xcccc +#define DISABLE_LOCK_3 0xdddd + u32 disable; + + u32 prescale_lock; +#define PRESCALE_LOCK_1 0x5a5a +#define PRESCALE_LOCK_2 0xa5a5 + u32 prescale; +}; + +static struct wdt_regs* regs = (struct wdt_regs *)TNETV107X_WDT0_ARM_BASE; + +#define wdt_reg_read(reg) __raw_readl(®s->reg) +#define wdt_reg_write(reg, val) __raw_writel((val), ®s->reg) + +static int write_prescale_reg(unsigned long prescale_value) +{ + wdt_reg_write(prescale_lock, PRESCALE_LOCK_1); + if ((wdt_reg_read(prescale_lock) & 0x3) != 0x1) + return -1; + + wdt_reg_write(prescale_lock, PRESCALE_LOCK_2); + if ((wdt_reg_read(prescale_lock) & 0x3) != 0x3) + return -1; + + wdt_reg_write(prescale, prescale_value); + + return 0; +} + +static int write_change_reg(unsigned long initial_timer_value) +{ + wdt_reg_write(change_lock, CHANGE_LOCK_1); + if ((wdt_reg_read(change_lock) & 0x3) != 0x1) + return -1; + + wdt_reg_write(change_lock, CHANGE_LOCK_2); + if ((wdt_reg_read(change_lock) & 0x3) != 0x3) + return -1; + + wdt_reg_write(change, initial_timer_value); + + return 0; +} + +static int wdt_control(unsigned long disable_value) +{ + wdt_reg_write(disable_lock, DISABLE_LOCK_1); + if ((wdt_reg_read(disable_lock) & 0x3) != 0x1) + return -1; + + wdt_reg_write(disable_lock, DISABLE_LOCK_2); + if ((wdt_reg_read(disable_lock) & 0x3) != 0x2) + return -1; + + wdt_reg_write(disable_lock, DISABLE_LOCK_3); + if ((wdt_reg_read(disable_lock) & 0x3) != 0x3) + return -1; + + wdt_reg_write(disable, disable_value); + return 0; +} + +static int wdt_set_period(unsigned long msec) +{ + unsigned long change_value, count_value; + unsigned long prescale_value = 1; + unsigned long refclk_khz, maxdiv; + int ret; + + refclk_khz = clk_get_rate(TNETV107X_LPSC_WDT_ARM); + maxdiv = (MAX_DIV / refclk_khz); + + if ((!msec) || (msec > maxdiv)) + return -1; + + count_value = refclk_khz * msec; + if (count_value > 0xffff) { + change_value = count_value / 0xffff + 1; + prescale_value = count_value / change_value; + } else { + change_value = count_value; + } + + ret = write_prescale_reg(prescale_value - 1); + if (ret) + return ret; + + ret = write_change_reg(change_value); + if (ret) + return ret; + + return 0; +} + +unsigned long last_wdt = -1; + +int wdt_start(unsigned long msecs) +{ + int ret; + ret = wdt_control(0); + if (ret) + return ret; + ret = wdt_set_period(msecs); + if (ret) + return ret; + ret = wdt_control(1); + if (ret) + return ret; + ret = wdt_kick(); + last_wdt = msecs; + return ret; +} + +int wdt_stop(void) +{ + last_wdt = -1; + return wdt_control(0); +} + +int wdt_kick(void) +{ + wdt_reg_write(kick_lock, KICK_LOCK_1); + if ((wdt_reg_read(kick_lock) & 0x3) != 0x1) + return -1; + + wdt_reg_write(kick_lock, KICK_LOCK_2); + if ((wdt_reg_read(kick_lock) & 0x3) != 0x3) + return -1; + + wdt_reg_write(kick, 1); + return 0; +} + +void reset_cpu(ulong addr) +{ + clk_enable(TNETV107X_LPSC_WDT_ARM); + wdt_start(1); + wdt_kick(); +} |
