1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2013 Altera Corporation <www.altera.com>
12 #include <linux/bitops.h>
14 #define DW_WDT_CR 0x00
15 #define DW_WDT_TORR 0x04
16 #define DW_WDT_CRR 0x0C
18 #define DW_WDT_CR_EN_OFFSET 0x00
19 #define DW_WDT_CR_RMOD_OFFSET 0x01
20 #define DW_WDT_CRR_RESTART_VAL 0x76
22 struct designware_wdt_priv {
25 struct reset_ctl_bulk resets;
29 * Set the watchdog time interval.
32 static int designware_wdt_settimeout(void __iomem *base, unsigned int clk_khz,
37 /* calculate the timeout range value */
38 i = fls(timeout * clk_khz - 1) - 16;
41 writel(i | (i << 4), base + DW_WDT_TORR);
46 static void designware_wdt_enable(void __iomem *base)
48 writel(BIT(DW_WDT_CR_EN_OFFSET), base + DW_WDT_CR);
51 static unsigned int designware_wdt_is_enabled(void __iomem *base)
53 return readl(base + DW_WDT_CR) & BIT(0);
56 static void designware_wdt_reset_common(void __iomem *base)
58 if (designware_wdt_is_enabled(base))
59 /* restart the watchdog counter */
60 writel(DW_WDT_CRR_RESTART_VAL, base + DW_WDT_CRR);
63 #if !CONFIG_IS_ENABLED(WDT)
64 void hw_watchdog_reset(void)
66 designware_wdt_reset_common((void __iomem *)CONFIG_DW_WDT_BASE);
69 void hw_watchdog_init(void)
71 /* reset to disable the watchdog */
73 /* set timer in miliseconds */
74 designware_wdt_settimeout((void __iomem *)CONFIG_DW_WDT_BASE,
75 CONFIG_DW_WDT_CLOCK_KHZ,
76 CONFIG_WATCHDOG_TIMEOUT_MSECS);
77 /* enable the watchdog */
78 designware_wdt_enable((void __iomem *)CONFIG_DW_WDT_BASE);
79 /* reset the watchdog */
83 static int designware_wdt_reset(struct udevice *dev)
85 struct designware_wdt_priv *priv = dev_get_priv(dev);
87 designware_wdt_reset_common(priv->base);
92 static int designware_wdt_stop(struct udevice *dev)
94 struct designware_wdt_priv *priv = dev_get_priv(dev);
96 designware_wdt_reset(dev);
97 writel(0, priv->base + DW_WDT_CR);
99 if (CONFIG_IS_ENABLED(DM_RESET)) {
102 ret = reset_assert_bulk(&priv->resets);
106 ret = reset_deassert_bulk(&priv->resets);
114 static int designware_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
116 struct designware_wdt_priv *priv = dev_get_priv(dev);
118 designware_wdt_stop(dev);
120 /* set timer in miliseconds */
121 designware_wdt_settimeout(priv->base, priv->clk_khz, timeout);
123 designware_wdt_enable(priv->base);
125 /* reset the watchdog */
126 return designware_wdt_reset(dev);
129 static int designware_wdt_probe(struct udevice *dev)
131 struct designware_wdt_priv *priv = dev_get_priv(dev);
132 __maybe_unused int ret;
134 priv->base = dev_remap_addr(dev);
138 #if CONFIG_IS_ENABLED(CLK)
141 ret = clk_get_by_index(dev, 0, &clk);
145 ret = clk_enable(&clk);
149 priv->clk_khz = clk_get_rate(&clk) / 1000;
150 if (!priv->clk_khz) {
155 priv->clk_khz = CONFIG_DW_WDT_CLOCK_KHZ;
158 if (CONFIG_IS_ENABLED(DM_RESET)) {
159 ret = reset_get_bulk(dev, &priv->resets);
163 ret = reset_deassert_bulk(&priv->resets);
168 /* reset to disable the watchdog */
169 return designware_wdt_stop(dev);
172 #if CONFIG_IS_ENABLED(CLK)
178 static const struct wdt_ops designware_wdt_ops = {
179 .start = designware_wdt_start,
180 .reset = designware_wdt_reset,
181 .stop = designware_wdt_stop,
184 static const struct udevice_id designware_wdt_ids[] = {
185 { .compatible = "snps,dw-wdt"},
189 U_BOOT_DRIVER(designware_wdt) = {
190 .name = "designware_wdt",
192 .of_match = designware_wdt_ids,
193 .priv_auto = sizeof(struct designware_wdt_priv),
194 .probe = designware_wdt_probe,
195 .ops = &designware_wdt_ops,
196 .flags = DM_FLAG_PRE_RELOC,