1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Designware APB Timer driver
4 *
5 * Copyright (C) 2018 Marek Vasut <marex@denx.de>
6 */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <clk.h>
11 #include <timer.h>
12
13 #include <asm/io.h>
14 #include <asm/arch/timer.h>
15
16 #define DW_APB_LOAD_VAL 0x0
17 #define DW_APB_CURR_VAL 0x4
18 #define DW_APB_CTRL 0x8
19
20 DECLARE_GLOBAL_DATA_PTR;
21
22 struct dw_apb_timer_priv {
23 fdt_addr_t regs;
24 };
25
dw_apb_timer_get_count(struct udevice * dev,u64 * count)26 static int dw_apb_timer_get_count(struct udevice *dev, u64 *count)
27 {
28 struct dw_apb_timer_priv *priv = dev_get_priv(dev);
29
30 /*
31 * The DW APB counter counts down, but this function
32 * requires the count to be incrementing. Invert the
33 * result.
34 */
35 *count = ~readl(priv->regs + DW_APB_CURR_VAL);
36
37 return 0;
38 }
39
dw_apb_timer_probe(struct udevice * dev)40 static int dw_apb_timer_probe(struct udevice *dev)
41 {
42 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
43 struct dw_apb_timer_priv *priv = dev_get_priv(dev);
44 struct clk clk;
45 int ret;
46
47 ret = clk_get_by_index(dev, 0, &clk);
48 if (ret)
49 return ret;
50
51 uc_priv->clock_rate = clk_get_rate(&clk);
52
53 clk_free(&clk);
54
55 /* init timer */
56 writel(0xffffffff, priv->regs + DW_APB_LOAD_VAL);
57 writel(0xffffffff, priv->regs + DW_APB_CURR_VAL);
58 setbits_le32(priv->regs + DW_APB_CTRL, 0x3);
59
60 return 0;
61 }
62
dw_apb_timer_ofdata_to_platdata(struct udevice * dev)63 static int dw_apb_timer_ofdata_to_platdata(struct udevice *dev)
64 {
65 struct dw_apb_timer_priv *priv = dev_get_priv(dev);
66
67 priv->regs = dev_read_addr(dev);
68
69 return 0;
70 }
71
72 static const struct timer_ops dw_apb_timer_ops = {
73 .get_count = dw_apb_timer_get_count,
74 };
75
76 static const struct udevice_id dw_apb_timer_ids[] = {
77 { .compatible = "snps,dw-apb-timer" },
78 {}
79 };
80
81 U_BOOT_DRIVER(dw_apb_timer) = {
82 .name = "dw_apb_timer",
83 .id = UCLASS_TIMER,
84 .ops = &dw_apb_timer_ops,
85 .probe = dw_apb_timer_probe,
86 .of_match = dw_apb_timer_ids,
87 .ofdata_to_platdata = dw_apb_timer_ofdata_to_platdata,
88 .priv_auto_alloc_size = sizeof(struct dw_apb_timer_priv),
89 };
90