arch/arm/mach-imx/system.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 1999 ARM Limited
   4  * Copyright (C) 2000 Deep Blue Solutions Ltd
   5  * Copyright 2006-2007 Freescale Semiconductor, Inc. All Rights Reserved.
   6  * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
   7  * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/clk.h>
  12 #include <linux/io.h>
  13 #include <linux/err.h>
  14 #include <linux/delay.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17
  18 #include <asm/system_misc.h>
  19 #include <asm/proc-fns.h>
  20 #include <asm/mach-types.h>
  21 #include <asm/hardware/cache-l2x0.h>
  22
  23 #include "common.h"
  24 #include "hardware.h"
  25
  26 static void __iomem *wdog_base;
  27 static struct clk *wdog_clk;
  28 static int wcr_enable = (1 << 2);
  29
  30 /*
  31  * Reset the system. It is called by machine_restart().
  32  */
  33 void mxc_restart(enum reboot_mode mode, const char *cmd)
  34 {
  35         if (!wdog_base)
  36                 goto reset_fallback;
  37
  38         if (!IS_ERR(wdog_clk))
  39                 clk_enable(wdog_clk);
  40
  41         /* Assert SRS signal */
  42         imx_writew(wcr_enable, wdog_base);
  43         /*
  44          * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
  45          * written twice), we add another two writes to ensure there must be at
  46          * least two writes happen in the same one 32kHz clock period.  We save
  47          * the target check here, since the writes shouldn't be a huge burden
  48          * for other platforms.
  49          */
  50         imx_writew(wcr_enable, wdog_base);
  51         imx_writew(wcr_enable, wdog_base);
  52
  53         /* wait for reset to assert... */
  54         mdelay(500);
  55
  56         pr_err("%s: Watchdog reset failed to assert reset\n", __func__);
  57
  58         /* delay to allow the serial port to show the message */
  59         mdelay(50);
  60
  61 reset_fallback:
  62         /* we'll take a jump through zero as a poor second */
  63         soft_restart(0);
  64 }
  65
  66 void __init mxc_arch_reset_init(void __iomem *base)
  67 {
  68         wdog_base = base;
  69
  70         wdog_clk = clk_get_sys("imx2-wdt.0", NULL);
  71         if (IS_ERR(wdog_clk))
  72                 pr_warn("%s: failed to get wdog clock\n", __func__);
  73         else
  74                 clk_prepare(wdog_clk);
  75 }
  76
  77 #ifdef CONFIG_SOC_IMX1
  78 void __init imx1_reset_init(void __iomem *base)
  79 {
  80         wcr_enable = (1 << 0);
  81         mxc_arch_reset_init(base);
  82 }
  83 #endif
  84
  85 #ifdef CONFIG_CACHE_L2X0
  86 void __init imx_init_l2cache(void)
  87 {
  88         void __iomem *l2x0_base;
  89         struct device_node *np;
  90         unsigned int val;
  91
  92         np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
  93         if (!np)
  94                 return;
  95
  96         l2x0_base = of_iomap(np, 0);
  97         if (!l2x0_base)
  98                 goto put_node;
  99
 100         if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & L2X0_CTRL_EN)) {
 101                 /* Configure the L2 PREFETCH and POWER registers */
 102                 val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL);
 103                 val |= L310_PREFETCH_CTRL_DBL_LINEFILL |
 104                         L310_PREFETCH_CTRL_INSTR_PREFETCH |
 105                         L310_PREFETCH_CTRL_DATA_PREFETCH;
 106
 107                 /* Set perfetch offset to improve performance */
 108                 val &= ~L310_PREFETCH_CTRL_OFFSET_MASK;
 109                 val |= 15;
 110
 111                 writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL);
 112         }
 113
 114         iounmap(l2x0_base);
 115 put_node:
 116         of_node_put(np);
 117 }
 118 #endif