xref: /linux/drivers/clk/x86/clk-fch.c (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
1 // SPDX-License-Identifier: MIT
2 /*
3  * clock framework for AMD Stoney based clocks
4  *
5  * Copyright 2018 Advanced Micro Devices, Inc.
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/clkdev.h>
10 #include <linux/clk-provider.h>
11 #include <linux/platform_data/clk-fch.h>
12 #include <linux/platform_device.h>
13 
14 /* Clock Driving Strength 2 register */
15 #define CLKDRVSTR2	0x28
16 /* Clock Control 1 register */
17 #define MISCCLKCNTL1	0x40
18 /* Auxiliary clock1 enable bit */
19 #define OSCCLKENB	2
20 /* 25Mhz auxiliary output clock freq bit */
21 #define OSCOUT1CLK25MHZ	16
22 
23 #define ST_CLK_48M	0
24 #define ST_CLK_25M	1
25 #define ST_CLK_MUX	2
26 #define ST_CLK_GATE	3
27 #define ST_MAX_CLKS	4
28 
29 #define RV_CLK_48M	0
30 #define RV_CLK_GATE	1
31 #define RV_MAX_CLKS	2
32 
33 static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
34 static struct clk_hw *hws[ST_MAX_CLKS];
35 
36 static int fch_clk_probe(struct platform_device *pdev)
37 {
38 	struct fch_clk_data *fch_data;
39 
40 	fch_data = dev_get_platdata(&pdev->dev);
41 	if (!fch_data || !fch_data->base)
42 		return -EINVAL;
43 
44 	if (!fch_data->is_rv) {
45 		hws[ST_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
46 			NULL, 0, 48000000);
47 		hws[ST_CLK_25M] = clk_hw_register_fixed_rate(NULL, "clk25MHz",
48 			NULL, 0, 25000000);
49 
50 		hws[ST_CLK_MUX] = clk_hw_register_mux(NULL, "oscout1_mux",
51 			clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
52 			0, fch_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0,
53 			NULL);
54 
55 		clk_set_parent(hws[ST_CLK_MUX]->clk, hws[ST_CLK_48M]->clk);
56 
57 		hws[ST_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1",
58 			"oscout1_mux", 0, fch_data->base + MISCCLKCNTL1,
59 			OSCCLKENB, CLK_GATE_SET_TO_DISABLE, NULL);
60 
61 		devm_clk_hw_register_clkdev(&pdev->dev, hws[ST_CLK_GATE],
62 			"oscout1", NULL);
63 	} else {
64 		hws[RV_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz",
65 			NULL, 0, 48000000);
66 
67 		hws[RV_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1",
68 			"clk48MHz", 0, fch_data->base + MISCCLKCNTL1,
69 			OSCCLKENB, CLK_GATE_SET_TO_DISABLE, NULL);
70 
71 		devm_clk_hw_register_clkdev(&pdev->dev, hws[RV_CLK_GATE],
72 			"oscout1", NULL);
73 	}
74 
75 	return 0;
76 }
77 
78 static int fch_clk_remove(struct platform_device *pdev)
79 {
80 	int i, clks;
81 	struct fch_clk_data *fch_data;
82 
83 	fch_data = dev_get_platdata(&pdev->dev);
84 
85 	clks = fch_data->is_rv ? RV_MAX_CLKS : ST_MAX_CLKS;
86 
87 	for (i = 0; i < clks; i++)
88 		clk_hw_unregister(hws[i]);
89 
90 	return 0;
91 }
92 
93 static struct platform_driver fch_clk_driver = {
94 	.driver = {
95 		.name = "clk-fch",
96 		.suppress_bind_attrs = true,
97 	},
98 	.probe = fch_clk_probe,
99 	.remove = fch_clk_remove,
100 };
101 builtin_platform_driver(fch_clk_driver);
102