1 // SPDX-License-Identifier: GPL-2.0+
3 * ARM PrimeCell Dual-Timer Module (SP804) driver
4 * Copyright (C) 2022 Arm Ltd.
12 #include <asm/global_data.h>
13 #include <dm/ofnode.h>
15 #include <dt-structs.h>
19 DECLARE_GLOBAL_DATA_PTR;
21 #define SP804_TIMERX_LOAD 0x00
22 #define SP804_TIMERX_VALUE 0x04
23 #define SP804_TIMERX_CONTROL 0x08
25 #define SP804_CTRL_TIMER_ENABLE (1U << 7)
26 #define SP804_CTRL_TIMER_PERIODIC (1U << 6)
27 #define SP804_CTRL_INT_ENABLE (1U << 5)
28 #define SP804_CTRL_TIMER_PRESCALE_SHIFT 2
29 #define SP804_CTRL_TIMER_PRESCALE_MASK (3U << SP804_CTRL_TIMER_PRESCALE_SHIFT)
30 #define SP804_CTRL_TIMER_32BIT (1U << 1)
31 #define SP804_CTRL_ONESHOT (1U << 0)
34 struct sp804_timer_plat {
38 static u64 sp804_timer_get_count(struct udevice *dev)
40 struct sp804_timer_plat *plat = dev_get_plat(dev);
41 uint32_t cntr = readl(plat->base + SP804_TIMERX_VALUE);
43 /* timers are down-counting */
47 static int sp804_clk_of_to_plat(struct udevice *dev)
49 struct sp804_timer_plat *plat = dev_get_plat(dev);
51 plat->base = dev_read_addr(dev);
58 static int sp804_timer_probe(struct udevice *dev)
60 struct sp804_timer_plat *plat = dev_get_plat(dev);
61 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
63 unsigned int divider = 1;
67 ctlr = readl(plat->base + SP804_TIMERX_CONTROL);
68 ctlr &= SP804_CTRL_TIMER_PRESCALE_MASK;
69 switch (ctlr >> SP804_CTRL_TIMER_PRESCALE_SHIFT) {
70 case 0x0: divider = 1; break;
71 case 0x1: divider = 16; break;
72 case 0x2: divider = 256; break;
73 case 0x3: printf("illegal!\n"); break;
76 ret = clk_get_by_index(dev, 0, &base_clk);
78 printf("could not find SP804 timer base clock in DT\n");
82 uc_priv->clock_rate = clk_get_rate(&base_clk) / divider;
84 /* keep divider, free-running, wrapping, no IRQs, 32-bit mode */
85 ctlr |= SP804_CTRL_TIMER_32BIT | SP804_CTRL_TIMER_ENABLE;
86 writel(ctlr, plat->base + SP804_TIMERX_CONTROL);
91 static const struct timer_ops sp804_timer_ops = {
92 .get_count = sp804_timer_get_count,
95 static const struct udevice_id sp804_timer_ids[] = {
96 { .compatible = "arm,sp804" },
100 U_BOOT_DRIVER(arm_sp804_timer) = {
101 .name = "arm_sp804_timer",
103 .of_match = sp804_timer_ids,
104 .probe = sp804_timer_probe,
105 .ops = &sp804_timer_ops,
106 .plat_auto = sizeof(struct sp804_timer_plat),
107 .of_to_plat = sp804_clk_of_to_plat,