1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Copyright (C) 2012 ARM Limited
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/clkdev.h>
8*4882a593Smuzhiyun #include <linux/clk-provider.h>
9*4882a593Smuzhiyun #include <linux/err.h>
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/of.h>
12*4882a593Smuzhiyun #include <linux/platform_device.h>
13*4882a593Smuzhiyun #include <linux/slab.h>
14*4882a593Smuzhiyun #include <linux/vexpress.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun struct vexpress_osc {
17*4882a593Smuzhiyun struct regmap *reg;
18*4882a593Smuzhiyun struct clk_hw hw;
19*4882a593Smuzhiyun unsigned long rate_min;
20*4882a593Smuzhiyun unsigned long rate_max;
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun #define to_vexpress_osc(osc) container_of(osc, struct vexpress_osc, hw)
24*4882a593Smuzhiyun
vexpress_osc_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)25*4882a593Smuzhiyun static unsigned long vexpress_osc_recalc_rate(struct clk_hw *hw,
26*4882a593Smuzhiyun unsigned long parent_rate)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun struct vexpress_osc *osc = to_vexpress_osc(hw);
29*4882a593Smuzhiyun u32 rate;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun regmap_read(osc->reg, 0, &rate);
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun return rate;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
vexpress_osc_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)36*4882a593Smuzhiyun static long vexpress_osc_round_rate(struct clk_hw *hw, unsigned long rate,
37*4882a593Smuzhiyun unsigned long *parent_rate)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun struct vexpress_osc *osc = to_vexpress_osc(hw);
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun if (osc->rate_min && rate < osc->rate_min)
42*4882a593Smuzhiyun rate = osc->rate_min;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun if (osc->rate_max && rate > osc->rate_max)
45*4882a593Smuzhiyun rate = osc->rate_max;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun return rate;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun
vexpress_osc_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)50*4882a593Smuzhiyun static int vexpress_osc_set_rate(struct clk_hw *hw, unsigned long rate,
51*4882a593Smuzhiyun unsigned long parent_rate)
52*4882a593Smuzhiyun {
53*4882a593Smuzhiyun struct vexpress_osc *osc = to_vexpress_osc(hw);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun return regmap_write(osc->reg, 0, rate);
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun static const struct clk_ops vexpress_osc_ops = {
59*4882a593Smuzhiyun .recalc_rate = vexpress_osc_recalc_rate,
60*4882a593Smuzhiyun .round_rate = vexpress_osc_round_rate,
61*4882a593Smuzhiyun .set_rate = vexpress_osc_set_rate,
62*4882a593Smuzhiyun };
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun
vexpress_osc_probe(struct platform_device * pdev)65*4882a593Smuzhiyun static int vexpress_osc_probe(struct platform_device *pdev)
66*4882a593Smuzhiyun {
67*4882a593Smuzhiyun struct clk_init_data init;
68*4882a593Smuzhiyun struct vexpress_osc *osc;
69*4882a593Smuzhiyun u32 range[2];
70*4882a593Smuzhiyun int ret;
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun osc = devm_kzalloc(&pdev->dev, sizeof(*osc), GFP_KERNEL);
73*4882a593Smuzhiyun if (!osc)
74*4882a593Smuzhiyun return -ENOMEM;
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun osc->reg = devm_regmap_init_vexpress_config(&pdev->dev);
77*4882a593Smuzhiyun if (IS_ERR(osc->reg))
78*4882a593Smuzhiyun return PTR_ERR(osc->reg);
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun if (of_property_read_u32_array(pdev->dev.of_node, "freq-range", range,
81*4882a593Smuzhiyun ARRAY_SIZE(range)) == 0) {
82*4882a593Smuzhiyun osc->rate_min = range[0];
83*4882a593Smuzhiyun osc->rate_max = range[1];
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun if (of_property_read_string(pdev->dev.of_node, "clock-output-names",
87*4882a593Smuzhiyun &init.name) != 0)
88*4882a593Smuzhiyun init.name = dev_name(&pdev->dev);
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun init.ops = &vexpress_osc_ops;
91*4882a593Smuzhiyun init.flags = 0;
92*4882a593Smuzhiyun init.num_parents = 0;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun osc->hw.init = &init;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun ret = devm_clk_hw_register(&pdev->dev, &osc->hw);
97*4882a593Smuzhiyun if (ret < 0)
98*4882a593Smuzhiyun return ret;
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, &osc->hw);
101*4882a593Smuzhiyun clk_hw_set_rate_range(&osc->hw, osc->rate_min, osc->rate_max);
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun dev_dbg(&pdev->dev, "Registered clock '%s'\n", init.name);
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun return 0;
106*4882a593Smuzhiyun }
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun static const struct of_device_id vexpress_osc_of_match[] = {
109*4882a593Smuzhiyun { .compatible = "arm,vexpress-osc", },
110*4882a593Smuzhiyun {}
111*4882a593Smuzhiyun };
112*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, vexpress_osc_of_match);
113*4882a593Smuzhiyun
114*4882a593Smuzhiyun static struct platform_driver vexpress_osc_driver = {
115*4882a593Smuzhiyun .driver = {
116*4882a593Smuzhiyun .name = "vexpress-osc",
117*4882a593Smuzhiyun .of_match_table = vexpress_osc_of_match,
118*4882a593Smuzhiyun },
119*4882a593Smuzhiyun .probe = vexpress_osc_probe,
120*4882a593Smuzhiyun };
121*4882a593Smuzhiyun module_platform_driver(vexpress_osc_driver);
122*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
123