1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2016 Synopsys, Inc. All rights reserved.
10 #include <asm/arcregs.h>
13 DECLARE_GLOBAL_DATA_PTR;
15 #define NH_MODE (1 << 1)
18 * ARC timer control registers are mapped to auxiliary address space.
19 * There are special ARC asm command to access that addresses.
20 * Therefore we use built-in functions to read from and write to timer
24 /* Driver private data. Contains timer id. Could be either 0 or 1. */
25 struct arc_timer_priv {
29 static u64 arc_timer_get_count(struct udevice *dev)
32 struct arc_timer_priv *priv = dev_get_priv(dev);
34 switch (priv->timer_id) {
36 val = read_aux_reg(ARC_AUX_TIMER0_CNT);
39 val = read_aux_reg(ARC_AUX_TIMER1_CNT);
42 return timer_conv_64(val);
45 static int arc_timer_probe(struct udevice *dev)
48 struct arc_timer_priv *priv = dev_get_priv(dev);
50 /* Get registers offset and size */
51 id = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", -1);
58 priv->timer_id = (uint)id;
61 * In ARC core there're special registers (Auxiliary or AUX) in its
62 * separate memory space that are used for accessing some hardware
63 * features of the core. They are not mapped in normal memory space
64 * and also always have the same location regardless core configuration.
65 * Thus to simplify understanding of the programming model we chose to
66 * access AUX regs of Timer0 and Timer1 separately instead of using
67 * offsets from some base address.
70 switch (priv->timer_id) {
72 /* Disable timer if CPU is halted */
73 write_aux_reg(ARC_AUX_TIMER0_CTRL, NH_MODE);
74 /* Set max value for counter/timer */
75 write_aux_reg(ARC_AUX_TIMER0_LIMIT, 0xffffffff);
76 /* Set initial count value and restart counter/timer */
77 write_aux_reg(ARC_AUX_TIMER0_CNT, 0);
80 /* Disable timer if CPU is halted */
81 write_aux_reg(ARC_AUX_TIMER1_CTRL, NH_MODE);
82 /* Set max value for counter/timer */
83 write_aux_reg(ARC_AUX_TIMER1_LIMIT, 0xffffffff);
84 /* Set initial count value and restart counter/timer */
85 write_aux_reg(ARC_AUX_TIMER1_CNT, 0);
93 static const struct timer_ops arc_timer_ops = {
94 .get_count = arc_timer_get_count,
97 static const struct udevice_id arc_timer_ids[] = {
98 { .compatible = "snps,arc-timer" },
102 U_BOOT_DRIVER(arc_timer) = {
105 .of_match = arc_timer_ids,
106 .probe = arc_timer_probe,
107 .ops = &arc_timer_ops,
108 .priv_auto = sizeof(struct arc_timer_priv),