blob: c692a6d0b89992698e5ccc98cadfa14913753111 [file] [log] [blame]
Liviu Dudaua71e9072018-09-17 17:50:00 +01001// 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
17struct vexpress_osc_clk_priv {
18 u8 osc;
19 ulong rate_min;
20 ulong rate_max;
21};
22
23static 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));
Simon Glass8729b1a2018-11-06 15:21:39 -070032 if (err < 0)
Liviu Dudaua71e9072018-09-17 17:50:00 +010033 return err;
34
35 return data;
36}
37
38#ifndef CONFIG_SPL_BUILD
39static 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));
Simon Glass8729b1a2018-11-06 15:21:39 -070056 if (err < 0)
Liviu Dudaua71e9072018-09-17 17:50:00 +010057 return err;
58
59 return rate;
60}
61#endif
62
63static 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
70static 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
97static const struct udevice_id vexpress_osc_clk_ids[] = {
98 { .compatible = "arm,vexpress-osc", },
99 {}
100};
101
102U_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};