1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2018 Arm Ltd
4 * Author: Liviu Dudau <liviu.dudau@foss.arm.com>
5 *
6 */
7 #define DEBUG
8 #include <common.h>
9 #include <clk-uclass.h>
10 #include <dm.h>
11 #include <dm/lists.h>
12 #include <errno.h>
13 #include <misc.h>
14
15 #define CLK_FUNCTION BIT(20)
16
17 struct vexpress_osc_clk_priv {
18 u8 osc;
19 ulong rate_min;
20 ulong rate_max;
21 };
22
vexpress_osc_clk_get_rate(struct clk * clk)23 static ulong vexpress_osc_clk_get_rate(struct clk *clk)
24 {
25 int err;
26 u32 data;
27 struct udevice *vexpress_cfg = dev_get_parent(clk->dev);
28 struct vexpress_osc_clk_priv *priv = dev_get_priv(clk->dev);
29
30 data = CLK_FUNCTION | priv->osc;
31 err = misc_read(vexpress_cfg, 0, &data, sizeof(data));
32 if (err < 0)
33 return err;
34
35 return data;
36 }
37
38 #ifndef CONFIG_SPL_BUILD
vexpress_osc_clk_set_rate(struct clk * clk,ulong rate)39 static ulong vexpress_osc_clk_set_rate(struct clk *clk, ulong rate)
40 {
41 int err;
42 u32 buffer[2];
43 struct udevice *vexpress_cfg = dev_get_parent(clk->dev);
44 struct vexpress_osc_clk_priv *priv = dev_get_priv(clk->dev);
45
46 if (rate < priv->rate_min || rate > priv->rate_max)
47 return -EINVAL;
48
49 /*
50 * we are sending the parent the info about the oscillator
51 * and the value we want to set
52 */
53 buffer[0] = CLK_FUNCTION | priv->osc;
54 buffer[1] = rate;
55 err = misc_write(vexpress_cfg, 0, buffer, 2 * sizeof(u32));
56 if (err < 0)
57 return err;
58
59 return rate;
60 }
61 #endif
62
63 static struct clk_ops vexpress_osc_clk_ops = {
64 .get_rate = vexpress_osc_clk_get_rate,
65 #ifndef CONFIG_SPL_BUILD
66 .set_rate = vexpress_osc_clk_set_rate,
67 #endif
68 };
69
vexpress_osc_clk_probe(struct udevice * dev)70 static int vexpress_osc_clk_probe(struct udevice *dev)
71 {
72 struct vexpress_osc_clk_priv *priv = dev_get_priv(dev);
73 u32 values[2];
74 int err;
75
76 err = dev_read_u32_array(dev, "freq-range", values, 2);
77 if (err)
78 return err;
79 priv->rate_min = values[0];
80 priv->rate_max = values[1];
81
82 err = dev_read_u32_array(dev, "arm,vexpress-sysreg,func", values, 2);
83 if (err)
84 return err;
85
86 if (values[0] != 1) {
87 dev_err(dev, "Invalid VExpress function for clock, must be '1'");
88 return -EINVAL;
89 }
90 priv->osc = values[1];
91 debug("clk \"%s%d\", min freq %luHz, max freq %luHz\n", dev->name,
92 priv->osc, priv->rate_min, priv->rate_max);
93
94 return 0;
95 }
96
97 static const struct udevice_id vexpress_osc_clk_ids[] = {
98 { .compatible = "arm,vexpress-osc", },
99 {}
100 };
101
102 U_BOOT_DRIVER(vexpress_osc_clk) = {
103 .name = "vexpress_osc_clk",
104 .id = UCLASS_CLK,
105 .of_match = vexpress_osc_clk_ids,
106 .ops = &vexpress_osc_clk_ops,
107 .priv_auto_alloc_size = sizeof(struct vexpress_osc_clk_priv),
108 .probe = vexpress_osc_clk_probe,
109 };
110