1 // SPDX-License-Identifier: GPL-2.0+
3 * Marvell Armada 37xx SoC Watchdog Driver
5 * Marek BehĂșn <kabel@kernel.org>
11 #include <asm/global_data.h>
13 #include <asm/arch/cpu.h>
14 #include <asm/arch/soc.h>
15 #include <dm/device_compat.h>
17 DECLARE_GLOBAL_DATA_PTR;
20 void __iomem *sel_reg;
27 * We use Counter 1 as watchdog timer, and Counter 0 for re-triggering Counter 1
30 #define CNTR_CTRL(id) ((id) * 0x10)
31 #define CNTR_CTRL_ENABLE 0x0001
32 #define CNTR_CTRL_ACTIVE 0x0002
33 #define CNTR_CTRL_MODE_MASK 0x000c
34 #define CNTR_CTRL_MODE_ONESHOT 0x0000
35 #define CNTR_CTRL_MODE_HWSIG 0x000c
36 #define CNTR_CTRL_TRIG_SRC_MASK 0x00f0
37 #define CNTR_CTRL_TRIG_SRC_PREV_CNTR 0x0050
38 #define CNTR_CTRL_PRESCALE_MASK 0xff00
39 #define CNTR_CTRL_PRESCALE_MIN 2
40 #define CNTR_CTRL_PRESCALE_SHIFT 8
42 #define CNTR_COUNT_LOW(id) (CNTR_CTRL(id) + 0x4)
43 #define CNTR_COUNT_HIGH(id) (CNTR_CTRL(id) + 0x8)
45 static void set_counter_value(struct a37xx_wdt *priv, int id, u64 val)
47 writel(val & 0xffffffff, priv->reg + CNTR_COUNT_LOW(id));
48 writel(val >> 32, priv->reg + CNTR_COUNT_HIGH(id));
51 static void counter_enable(struct a37xx_wdt *priv, int id)
53 setbits_le32(priv->reg + CNTR_CTRL(id), CNTR_CTRL_ENABLE);
56 static void counter_disable(struct a37xx_wdt *priv, int id)
58 clrbits_le32(priv->reg + CNTR_CTRL(id), CNTR_CTRL_ENABLE);
61 static void init_counter(struct a37xx_wdt *priv, int id, u32 mode, u32 trig_src)
65 reg = readl(priv->reg + CNTR_CTRL(id));
67 reg &= ~(CNTR_CTRL_MODE_MASK | CNTR_CTRL_PRESCALE_MASK |
68 CNTR_CTRL_TRIG_SRC_MASK);
73 /* set prescaler to the min value */
74 reg |= CNTR_CTRL_PRESCALE_MIN << CNTR_CTRL_PRESCALE_SHIFT;
76 /* set trigger source */
79 writel(reg, priv->reg + CNTR_CTRL(id));
82 static int a37xx_wdt_reset(struct udevice *dev)
84 struct a37xx_wdt *priv = dev_get_priv(dev);
89 /* counter 1 is retriggered by forcing end count on counter 0 */
90 counter_disable(priv, 0);
91 counter_enable(priv, 0);
96 static int a37xx_wdt_expire_now(struct udevice *dev, ulong flags)
98 struct a37xx_wdt *priv = dev_get_priv(dev);
100 /* first we set timeout to 0 */
101 counter_disable(priv, 1);
102 set_counter_value(priv, 1, 0);
103 counter_enable(priv, 1);
105 /* and then we start counter 1 by forcing end count on counter 0 */
106 counter_disable(priv, 0);
107 counter_enable(priv, 0);
112 static int a37xx_wdt_start(struct udevice *dev, u64 ms, ulong flags)
114 struct a37xx_wdt *priv = dev_get_priv(dev);
116 init_counter(priv, 0, CNTR_CTRL_MODE_ONESHOT, 0);
117 init_counter(priv, 1, CNTR_CTRL_MODE_HWSIG, CNTR_CTRL_TRIG_SRC_PREV_CNTR);
119 priv->timeout = ms * priv->clk_rate / 1000 / CNTR_CTRL_PRESCALE_MIN;
121 set_counter_value(priv, 0, 0);
122 set_counter_value(priv, 1, priv->timeout);
123 counter_enable(priv, 1);
125 /* we have to force end count on counter 0 to start counter 1 */
126 counter_enable(priv, 0);
131 static int a37xx_wdt_stop(struct udevice *dev)
133 struct a37xx_wdt *priv = dev_get_priv(dev);
135 counter_disable(priv, 1);
136 counter_disable(priv, 0);
137 writel(0, priv->sel_reg);
142 static int a37xx_wdt_probe(struct udevice *dev)
144 struct a37xx_wdt *priv = dev_get_priv(dev);
147 priv->sel_reg = (void __iomem *)MVEBU_REGISTER(0x0d064);
149 addr = dev_read_addr(dev);
150 if (addr == FDT_ADDR_T_NONE)
152 priv->reg = (void __iomem *)addr;
154 priv->clk_rate = (ulong)get_ref_clk() * 1000000;
157 * We use counter 1 as watchdog timer, therefore we only set bit
158 * TIMER1_IS_WCHDOG_TIMER. Counter 0 is only used to force re-trigger on
161 writel(1 << 1, priv->sel_reg);
165 dev_err(dev, "no io address\n");
169 static const struct wdt_ops a37xx_wdt_ops = {
170 .start = a37xx_wdt_start,
171 .reset = a37xx_wdt_reset,
172 .stop = a37xx_wdt_stop,
173 .expire_now = a37xx_wdt_expire_now,
176 static const struct udevice_id a37xx_wdt_ids[] = {
177 { .compatible = "marvell,armada-3700-wdt" },
181 U_BOOT_DRIVER(a37xx_wdt) = {
182 .name = "armada_37xx_wdt",
184 .of_match = a37xx_wdt_ids,
185 .probe = a37xx_wdt_probe,
186 .priv_auto = sizeof(struct a37xx_wdt),
187 .ops = &a37xx_wdt_ops,