1 /*
2 * watchdog.c - driver for i.mx on-chip watchdog
3 *
4 * Licensed under the GPL-2 or later.
5 */
6
7 #include <common.h>
8 #include <cpu_func.h>
9 #include <dm.h>
10 #include <hang.h>
11 #include <asm/io.h>
12 #include <wdt.h>
13 #include <watchdog.h>
14 #include <asm/arch/imx-regs.h>
15 #ifdef CONFIG_FSL_LSCH2
16 #include <asm/arch/immap_lsch2.h>
17 #endif
18 #include <fsl_wdog.h>
19 #include <div64.h>
20
21 #define TIMEOUT_MAX 128000
22 #define TIMEOUT_MIN 500
23
imx_watchdog_expire_now(struct watchdog_regs * wdog,bool ext_reset)24 static void imx_watchdog_expire_now(struct watchdog_regs *wdog, bool ext_reset)
25 {
26 u16 wcr = WCR_WDE;
27
28 if (ext_reset)
29 wcr |= WCR_SRS; /* do not assert internal reset */
30 else
31 wcr |= WCR_WDA; /* do not assert external reset */
32
33 /* Write 3 times to ensure it works, due to IMX6Q errata ERR004346 */
34 writew(wcr, &wdog->wcr);
35 writew(wcr, &wdog->wcr);
36 writew(wcr, &wdog->wcr);
37
38 while (1) {
39 /*
40 * spin before reset
41 */
42 }
43 }
44
45 #if !defined(CONFIG_IMX_WATCHDOG) || \
46 (defined(CONFIG_IMX_WATCHDOG) && !CONFIG_IS_ENABLED(WDT))
reset_cpu(void)47 void __attribute__((weak)) reset_cpu(void)
48 {
49 struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
50
51 imx_watchdog_expire_now(wdog, true);
52 }
53 #endif
54
55 #if defined(CONFIG_IMX_WATCHDOG)
imx_watchdog_reset(struct watchdog_regs * wdog)56 static void imx_watchdog_reset(struct watchdog_regs *wdog)
57 {
58 #ifndef CONFIG_WATCHDOG_RESET_DISABLE
59 writew(0x5555, &wdog->wsr);
60 writew(0xaaaa, &wdog->wsr);
61 #endif /* CONFIG_WATCHDOG_RESET_DISABLE*/
62 }
63
imx_watchdog_init(struct watchdog_regs * wdog,bool ext_reset,u64 timeout)64 static void imx_watchdog_init(struct watchdog_regs *wdog, bool ext_reset,
65 u64 timeout)
66 {
67 u16 wcr;
68
69 /*
70 * The timer watchdog can be set between
71 * 0.5 and 128 Seconds. If not defined
72 * in configuration file, sets 128 Seconds
73 */
74 #ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
75 #define CONFIG_WATCHDOG_TIMEOUT_MSECS 128000
76 #endif
77
78 timeout = max_t(u64, timeout, TIMEOUT_MIN);
79 timeout = min_t(u64, timeout, TIMEOUT_MAX);
80 timeout = lldiv(timeout, 500) - 1;
81
82 #ifdef CONFIG_FSL_LSCH2
83 wcr = (WCR_WDA | WCR_SRS | WCR_WDE) << 8 | timeout;
84 #else
85 wcr = WCR_WDZST | WCR_WDBG | WCR_WDE | WCR_SRS |
86 WCR_WDA | SET_WCR_WT(timeout);
87 if (ext_reset)
88 wcr |= WCR_WDT;
89 #endif /* CONFIG_FSL_LSCH2*/
90 writew(wcr, &wdog->wcr);
91 imx_watchdog_reset(wdog);
92 }
93
94 #if !CONFIG_IS_ENABLED(WDT)
hw_watchdog_reset(void)95 void hw_watchdog_reset(void)
96 {
97 struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
98
99 imx_watchdog_reset(wdog);
100 }
101
hw_watchdog_init(void)102 void hw_watchdog_init(void)
103 {
104 struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
105
106 imx_watchdog_init(wdog, true, CONFIG_WATCHDOG_TIMEOUT_MSECS);
107 }
108 #else
109 struct imx_wdt_priv {
110 void __iomem *base;
111 bool ext_reset;
112 };
113
imx_wdt_reset(struct udevice * dev)114 static int imx_wdt_reset(struct udevice *dev)
115 {
116 struct imx_wdt_priv *priv = dev_get_priv(dev);
117
118 imx_watchdog_reset(priv->base);
119
120 return 0;
121 }
122
imx_wdt_expire_now(struct udevice * dev,ulong flags)123 static int imx_wdt_expire_now(struct udevice *dev, ulong flags)
124 {
125 struct imx_wdt_priv *priv = dev_get_priv(dev);
126
127 imx_watchdog_expire_now(priv->base, priv->ext_reset);
128 hang();
129
130 return 0;
131 }
132
imx_wdt_start(struct udevice * dev,u64 timeout,ulong flags)133 static int imx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
134 {
135 struct imx_wdt_priv *priv = dev_get_priv(dev);
136
137 imx_watchdog_init(priv->base, priv->ext_reset, timeout);
138
139 return 0;
140 }
141
imx_wdt_probe(struct udevice * dev)142 static int imx_wdt_probe(struct udevice *dev)
143 {
144 struct imx_wdt_priv *priv = dev_get_priv(dev);
145
146 priv->base = dev_read_addr_ptr(dev);
147 if (!priv->base)
148 return -ENOENT;
149
150 priv->ext_reset = dev_read_bool(dev, "fsl,ext-reset-output");
151
152 return 0;
153 }
154
155 static const struct wdt_ops imx_wdt_ops = {
156 .start = imx_wdt_start,
157 .reset = imx_wdt_reset,
158 .expire_now = imx_wdt_expire_now,
159 };
160
161 static const struct udevice_id imx_wdt_ids[] = {
162 { .compatible = "fsl,imx21-wdt" },
163 {}
164 };
165
166 U_BOOT_DRIVER(imx_wdt) = {
167 .name = "imx_wdt",
168 .id = UCLASS_WDT,
169 .of_match = imx_wdt_ids,
170 .probe = imx_wdt_probe,
171 .ops = &imx_wdt_ops,
172 .priv_auto = sizeof(struct imx_wdt_priv),
173 .flags = DM_FLAG_PRE_RELOC,
174 };
175 #endif
176 #endif
177