1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2017 Google, Inc
11 #include <asm/arch/wdt.h>
13 #define WDT_AST2500 2500
14 #define WDT_AST2400 2400
20 static int ast_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
22 struct ast_wdt_priv *priv = dev_get_priv(dev);
23 ulong driver_data = dev_get_driver_data(dev);
24 u32 reset_mode = ast_reset_mode_from_flags(flags);
26 /* 32 bits at 1MHz is 4294967ms */
27 timeout = min_t(u64, timeout, 4294967);
29 /* WDT counts in ticks of 1MHz clock. 1ms / 1e3 * 1e6 */
32 clrsetbits_le32(&priv->regs->ctrl,
33 WDT_CTRL_RESET_MASK << WDT_CTRL_RESET_MODE_SHIFT,
34 reset_mode << WDT_CTRL_RESET_MODE_SHIFT);
36 if (driver_data >= WDT_AST2500 && reset_mode == WDT_CTRL_RESET_SOC)
37 writel(ast_reset_mask_from_flags(flags),
38 &priv->regs->reset_mask);
40 writel((u32) timeout, &priv->regs->counter_reload_val);
41 writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart);
43 * Setting CLK1MHZ bit is just for compatibility with ast2400 part.
44 * On ast2500 watchdog timer clock is fixed at 1MHz and the bit is
47 setbits_le32(&priv->regs->ctrl,
48 WDT_CTRL_EN | WDT_CTRL_RESET | WDT_CTRL_CLK1MHZ);
53 static int ast_wdt_stop(struct udevice *dev)
55 struct ast_wdt_priv *priv = dev_get_priv(dev);
57 clrbits_le32(&priv->regs->ctrl, WDT_CTRL_EN);
59 writel(WDT_RESET_DEFAULT, &priv->regs->reset_mask);
63 static int ast_wdt_reset(struct udevice *dev)
65 struct ast_wdt_priv *priv = dev_get_priv(dev);
67 writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart);
72 static int ast_wdt_expire_now(struct udevice *dev, ulong flags)
74 struct ast_wdt_priv *priv = dev_get_priv(dev);
77 ret = ast_wdt_start(dev, 1, flags);
81 while (readl(&priv->regs->ctrl) & WDT_CTRL_EN)
84 return ast_wdt_stop(dev);
87 static int ast_wdt_ofdata_to_platdata(struct udevice *dev)
89 struct ast_wdt_priv *priv = dev_get_priv(dev);
91 priv->regs = devfdt_get_addr_ptr(dev);
92 if (IS_ERR(priv->regs))
93 return PTR_ERR(priv->regs);
98 static const struct wdt_ops ast_wdt_ops = {
99 .start = ast_wdt_start,
100 .reset = ast_wdt_reset,
101 .stop = ast_wdt_stop,
102 .expire_now = ast_wdt_expire_now,
105 static const struct udevice_id ast_wdt_ids[] = {
106 { .compatible = "aspeed,wdt", .data = WDT_AST2500 },
107 { .compatible = "aspeed,ast2500-wdt", .data = WDT_AST2500 },
108 { .compatible = "aspeed,ast2400-wdt", .data = WDT_AST2400 },
112 static int ast_wdt_probe(struct udevice *dev)
114 debug("%s() wdt%u\n", __func__, dev->seq);
120 U_BOOT_DRIVER(ast_wdt) = {
123 .of_match = ast_wdt_ids,
124 .probe = ast_wdt_probe,
125 .priv_auto_alloc_size = sizeof(struct ast_wdt_priv),
126 .ofdata_to_platdata = ast_wdt_ofdata_to_platdata,