1 /* 2 * OMAP2+ MPU WD_TIMER-specific code 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/io.h> 12 #include <linux/err.h> 13 14 #include <plat/omap_hwmod.h> 15 16 /* 17 * In order to avoid any assumptions from bootloader regarding WDT 18 * settings, WDT module is reset during init. This enables the watchdog 19 * timer. Hence it is required to disable the watchdog after the WDT reset 20 * during init. Otherwise the system would reboot as per the default 21 * watchdog timer registers settings. 22 */ 23 #define OMAP_WDT_WPS 0x34 24 #define OMAP_WDT_SPR 0x48 25 26 27 int omap2_wd_timer_disable(struct omap_hwmod *oh) 28 { 29 void __iomem *base; 30 31 if (!oh) { 32 pr_err("%s: Could not look up wdtimer_hwmod\n", __func__); 33 return -EINVAL; 34 } 35 36 base = omap_hwmod_get_mpu_rt_va(oh); 37 if (!base) { 38 pr_err("%s: Could not get the base address for %s\n", 39 oh->name, __func__); 40 return -EINVAL; 41 } 42 43 /* sequence required to disable watchdog */ 44 __raw_writel(0xAAAA, base + OMAP_WDT_SPR); 45 while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) 46 cpu_relax(); 47 48 __raw_writel(0x5555, base + OMAP_WDT_SPR); 49 while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) 50 cpu_relax(); 51 52 return 0; 53 } 54 55