1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * JZ4780 common routines 4 * 5 * Copyright (c) 2013 Imagination Technologies 6 * Author: Paul Burton <paul.burton@imgtec.com> 7 */ 8 9 #include <config.h> 10 #include <common.h> 11 #include <asm/io.h> 12 #include <mach/jz4780.h> 13 14 /* WDT */ 15 #define WDT_TDR 0x00 16 #define WDT_TCER 0x04 17 #define WDT_TCNT 0x08 18 #define WDT_TCSR 0x0C 19 20 /* Register definition */ 21 #define WDT_TCSR_PRESCALE_BIT 3 22 #define WDT_TCSR_PRESCALE_MASK (0x7 << WDT_TCSR_PRESCALE_BIT) 23 #define WDT_TCSR_PRESCALE1 (0x0 << WDT_TCSR_PRESCALE_BIT) 24 #define WDT_TCSR_PRESCALE4 (0x1 << WDT_TCSR_PRESCALE_BIT) 25 #define WDT_TCSR_PRESCALE16 (0x2 << WDT_TCSR_PRESCALE_BIT) 26 #define WDT_TCSR_PRESCALE64 (0x3 << WDT_TCSR_PRESCALE_BIT) 27 #define WDT_TCSR_PRESCALE256 (0x4 << WDT_TCSR_PRESCALE_BIT) 28 #define WDT_TCSR_PRESCALE1024 (0x5 << WDT_TCSR_PRESCALE_BIT) 29 #define WDT_TCSR_EXT_EN BIT(2) 30 #define WDT_TCSR_RTC_EN BIT(1) 31 #define WDT_TCSR_PCK_EN BIT(0) 32 33 #define WDT_TCER_TCEN BIT(0) 34 35 void _machine_restart(void) 36 { 37 void __iomem *wdt_regs = (void __iomem *)WDT_BASE; 38 39 /* EXTAL as the timer clock input. */ 40 writew(WDT_TCSR_PRESCALE1 | WDT_TCSR_EXT_EN, wdt_regs + WDT_TCSR); 41 42 /* Reset the WDT counter and timeout. */ 43 writew(0, wdt_regs + WDT_TCNT); 44 writew(0, wdt_regs + WDT_TDR); 45 46 jz4780_tcu_wdt_start(); 47 48 /* WDT start */ 49 writeb(WDT_TCER_TCEN, wdt_regs + WDT_TCER); 50 51 for (;;) 52 ; 53 } 54