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 <reset.h>
12 #include <timer.h>
13
14 #include <asm/io.h>
15 #include <asm/arch/timer.h>
16
17 #define DW_APB_LOAD_VAL 0x0
18 #define DW_APB_CURR_VAL 0x4
19 #define DW_APB_CTRL 0x8
20
21 struct dw_apb_timer_priv {
22 fdt_addr_t regs;
23 struct reset_ctl_bulk resets;
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 = timer_conv_64(~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 = reset_get_bulk(dev, &priv->resets);
48 if (ret)
49 dev_warn(dev, "Can't get reset: %d\n", ret);
50 else
51 reset_deassert_bulk(&priv->resets);
52
53 ret = clk_get_by_index(dev, 0, &clk);
54 if (ret)
55 return ret;
56
57 uc_priv->clock_rate = clk_get_rate(&clk);
58
59 clk_free(&clk);
60
61 /* init timer */
62 writel(0xffffffff, priv->regs + DW_APB_LOAD_VAL);
63 writel(0xffffffff, priv->regs + DW_APB_CURR_VAL);
64 setbits_le32(priv->regs + DW_APB_CTRL, 0x3);
65
66 return 0;
67 }
68
dw_apb_timer_ofdata_to_platdata(struct udevice * dev)69 static int dw_apb_timer_ofdata_to_platdata(struct udevice *dev)
70 {
71 struct dw_apb_timer_priv *priv = dev_get_priv(dev);
72
73 priv->regs = dev_read_addr(dev);
74
75 return 0;
76 }
77
dw_apb_timer_remove(struct udevice * dev)78 static int dw_apb_timer_remove(struct udevice *dev)
79 {
80 struct dw_apb_timer_priv *priv = dev_get_priv(dev);
81
82 return reset_release_bulk(&priv->resets);
83 }
84
85 static const struct timer_ops dw_apb_timer_ops = {
86 .get_count = dw_apb_timer_get_count,
87 };
88
89 static const struct udevice_id dw_apb_timer_ids[] = {
90 { .compatible = "snps,dw-apb-timer" },
91 {}
92 };
93
94 U_BOOT_DRIVER(dw_apb_timer) = {
95 .name = "dw_apb_timer",
96 .id = UCLASS_TIMER,
97 .ops = &dw_apb_timer_ops,
98 .probe = dw_apb_timer_probe,
99 .of_match = dw_apb_timer_ids,
100 .ofdata_to_platdata = dw_apb_timer_ofdata_to_platdata,
101 .remove = dw_apb_timer_remove,
102 .priv_auto_alloc_size = sizeof(struct dw_apb_timer_priv),
103 };
104