1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * (C) Copyright 2007-2008 4 * Stelian Pop <stelian@popies.net> 5 * Lead Tech Design <www.leadtechdesign.com> 6 * 7 * (C) Copyright 2012 8 * Markus Hubig <mhubig@imko.de> 9 * IMKO GmbH <www.imko.de> 10 * 11 * Copyright (C) 2013 DENX Software Engineering, hs@denx.de 12 */ 13 14 #include <common.h> 15 #include <asm/hardware.h> 16 #include <asm/io.h> 17 #include <linux/sizes.h> 18 #include <asm/arch/at91_rstc.h> 19 #include <watchdog.h> 20 21 void at91_phy_reset(void) 22 { 23 unsigned long erstl; 24 unsigned long start = get_timer(0); 25 unsigned long const timeout = 1000; /* 1000ms */ 26 at91_rstc_t *rstc = (at91_rstc_t *)ATMEL_BASE_RSTC; 27 28 erstl = readl(&rstc->mr) & AT91_RSTC_MR_ERSTL_MASK; 29 30 /* 31 * Need to reset PHY -> 500ms reset 32 * Reset PHY by pulling the NRST line for 500ms to low. To do so 33 * disable user reset for low level on NRST pin and poll the NRST 34 * level in reset status register. 35 */ 36 writel(AT91_RSTC_KEY | AT91_RSTC_MR_ERSTL(0x0D) | 37 AT91_RSTC_MR_URSTEN, &rstc->mr); 38 39 writel(AT91_RSTC_KEY | AT91_RSTC_CR_EXTRST, &rstc->cr); 40 41 /* Wait for end of hardware reset */ 42 while (!(readl(&rstc->sr) & AT91_RSTC_SR_NRSTL)) { 43 /* avoid shutdown by watchdog */ 44 WATCHDOG_RESET(); 45 mdelay(10); 46 47 /* timeout for not getting stuck in an endless loop */ 48 if (get_timer(start) >= timeout) { 49 puts("*** ERROR: Timeout waiting for PHY reset!\n"); 50 break; 51 } 52 }; 53 54 /* Restore NRST value */ 55 writel(AT91_RSTC_KEY | erstl | AT91_RSTC_MR_URSTEN, &rstc->mr); 56 } 57