1 /* 2 * Copyright (C) 1999 ARM Limited 3 * Copyright (C) 2000 Deep Blue Solutions Ltd 4 * Copyright 2006-2007 Freescale Semiconductor, Inc. All Rights Reserved. 5 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de 6 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 */ 18 19 #include <linux/kernel.h> 20 #include <linux/clk.h> 21 #include <linux/io.h> 22 #include <linux/err.h> 23 #include <linux/delay.h> 24 #include <linux/of.h> 25 #include <linux/of_address.h> 26 27 #include <asm/system_misc.h> 28 #include <asm/proc-fns.h> 29 #include <asm/mach-types.h> 30 #include <asm/hardware/cache-l2x0.h> 31 32 #include "common.h" 33 #include "hardware.h" 34 35 static void __iomem *wdog_base; 36 static struct clk *wdog_clk; 37 38 /* 39 * Reset the system. It is called by machine_restart(). 40 */ 41 void mxc_restart(enum reboot_mode mode, const char *cmd) 42 { 43 unsigned int wcr_enable; 44 45 if (!wdog_base) 46 goto reset_fallback; 47 48 if (!IS_ERR(wdog_clk)) 49 clk_enable(wdog_clk); 50 51 if (cpu_is_mx1()) 52 wcr_enable = (1 << 0); 53 else 54 wcr_enable = (1 << 2); 55 56 /* Assert SRS signal */ 57 __raw_writew(wcr_enable, wdog_base); 58 /* 59 * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be 60 * written twice), we add another two writes to ensure there must be at 61 * least two writes happen in the same one 32kHz clock period. We save 62 * the target check here, since the writes shouldn't be a huge burden 63 * for other platforms. 64 */ 65 __raw_writew(wcr_enable, wdog_base); 66 __raw_writew(wcr_enable, wdog_base); 67 68 /* wait for reset to assert... */ 69 mdelay(500); 70 71 pr_err("%s: Watchdog reset failed to assert reset\n", __func__); 72 73 /* delay to allow the serial port to show the message */ 74 mdelay(50); 75 76 reset_fallback: 77 /* we'll take a jump through zero as a poor second */ 78 soft_restart(0); 79 } 80 81 void __init mxc_arch_reset_init(void __iomem *base) 82 { 83 wdog_base = base; 84 85 wdog_clk = clk_get_sys("imx2-wdt.0", NULL); 86 if (IS_ERR(wdog_clk)) 87 pr_warn("%s: failed to get wdog clock\n", __func__); 88 else 89 clk_prepare(wdog_clk); 90 } 91 92 #ifdef CONFIG_CACHE_L2X0 93 void __init imx_init_l2cache(void) 94 { 95 void __iomem *l2x0_base; 96 struct device_node *np; 97 unsigned int val; 98 99 np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache"); 100 if (!np) 101 goto out; 102 103 l2x0_base = of_iomap(np, 0); 104 if (!l2x0_base) { 105 of_node_put(np); 106 goto out; 107 } 108 109 /* Configure the L2 PREFETCH and POWER registers */ 110 val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL); 111 val |= 0x70800000; 112 /* 113 * The L2 cache controller(PL310) version on the i.MX6D/Q is r3p1-50rel0 114 * The L2 cache controller(PL310) version on the i.MX6DL/SOLO/SL is r3p2 115 * But according to ARM PL310 errata: 752271 116 * ID: 752271: Double linefill feature can cause data corruption 117 * Fault Status: Present in: r3p0, r3p1, r3p1-50rel0. Fixed in r3p2 118 * Workaround: The only workaround to this erratum is to disable the 119 * double linefill feature. This is the default behavior. 120 */ 121 if (cpu_is_imx6q()) 122 val &= ~(1 << 30 | 1 << 23); 123 writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL); 124 125 iounmap(l2x0_base); 126 of_node_put(np); 127 128 out: 129 l2x0_of_init(0, ~0); 130 } 131 #endif 132