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_clk) 46 clk_enable(wdog_clk); 47 48 if (cpu_is_mx1()) 49 wcr_enable = (1 << 0); 50 else 51 wcr_enable = (1 << 2); 52 53 /* Assert SRS signal */ 54 __raw_writew(wcr_enable, wdog_base); 55 /* 56 * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be 57 * written twice), we add another two writes to ensure there must be at 58 * least two writes happen in the same one 32kHz clock period. We save 59 * the target check here, since the writes shouldn't be a huge burden 60 * for other platforms. 61 */ 62 __raw_writew(wcr_enable, wdog_base); 63 __raw_writew(wcr_enable, wdog_base); 64 65 /* wait for reset to assert... */ 66 mdelay(500); 67 68 pr_err("%s: Watchdog reset failed to assert reset\n", __func__); 69 70 /* delay to allow the serial port to show the message */ 71 mdelay(50); 72 73 /* we'll take a jump through zero as a poor second */ 74 soft_restart(0); 75 } 76 77 void __init mxc_arch_reset_init(void __iomem *base) 78 { 79 wdog_base = base; 80 81 wdog_clk = clk_get_sys("imx2-wdt.0", NULL); 82 if (IS_ERR(wdog_clk)) { 83 pr_warn("%s: failed to get wdog clock\n", __func__); 84 wdog_clk = NULL; 85 return; 86 } 87 88 clk_prepare(wdog_clk); 89 } 90 91 void __init mxc_arch_reset_init_dt(void) 92 { 93 struct device_node *np; 94 95 np = of_find_compatible_node(NULL, NULL, "fsl,imx21-wdt"); 96 wdog_base = of_iomap(np, 0); 97 WARN_ON(!wdog_base); 98 99 wdog_clk = of_clk_get(np, 0); 100 if (IS_ERR(wdog_clk)) { 101 pr_warn("%s: failed to get wdog clock\n", __func__); 102 wdog_clk = NULL; 103 return; 104 } 105 106 clk_prepare(wdog_clk); 107 } 108 109 #ifdef CONFIG_CACHE_L2X0 110 void __init imx_init_l2cache(void) 111 { 112 void __iomem *l2x0_base; 113 struct device_node *np; 114 unsigned int val; 115 116 np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache"); 117 if (!np) 118 goto out; 119 120 l2x0_base = of_iomap(np, 0); 121 if (!l2x0_base) { 122 of_node_put(np); 123 goto out; 124 } 125 126 /* Configure the L2 PREFETCH and POWER registers */ 127 val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL); 128 val |= 0x70800000; 129 /* 130 * The L2 cache controller(PL310) version on the i.MX6D/Q is r3p1-50rel0 131 * The L2 cache controller(PL310) version on the i.MX6DL/SOLO/SL is r3p2 132 * But according to ARM PL310 errata: 752271 133 * ID: 752271: Double linefill feature can cause data corruption 134 * Fault Status: Present in: r3p0, r3p1, r3p1-50rel0. Fixed in r3p2 135 * Workaround: The only workaround to this erratum is to disable the 136 * double linefill feature. This is the default behavior. 137 */ 138 if (cpu_is_imx6q()) 139 val &= ~(1 << 30 | 1 << 23); 140 writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL); 141 142 iounmap(l2x0_base); 143 of_node_put(np); 144 145 out: 146 l2x0_of_init(0, ~0); 147 } 148 #endif 149