xref: /linux/arch/arm/mach-imx/system.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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
119