xref: /linux/drivers/clk/tegra/clk-tegra-fixed.c (revision 75a6faf617d107bdbc74d36ccf89f2280b96ac26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012, 2013, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/io.h>
7 #include <linux/clk-provider.h>
8 #include <linux/of.h>
9 #include <linux/of_address.h>
10 #include <linux/delay.h>
11 #include <linux/export.h>
12 #include <linux/clk/tegra.h>
13 
14 #include "clk.h"
15 #include "clk-id.h"
16 
17 #define OSC_CTRL			0x50
18 #define OSC_CTRL_OSC_FREQ_SHIFT		28
19 #define OSC_CTRL_PLL_REF_DIV_SHIFT	26
20 
21 int __init tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
22 			      unsigned long *input_freqs, unsigned int num,
23 			      unsigned int clk_m_div, unsigned long *osc_freq,
24 			      unsigned long *pll_ref_freq)
25 {
26 	struct clk *clk, *osc;
27 	struct clk **dt_clk;
28 	u32 val, pll_ref_div;
29 	unsigned osc_idx;
30 
31 	val = readl_relaxed(clk_base + OSC_CTRL);
32 	osc_idx = val >> OSC_CTRL_OSC_FREQ_SHIFT;
33 
34 	if (osc_idx < num)
35 		*osc_freq = input_freqs[osc_idx];
36 	else
37 		*osc_freq = 0;
38 
39 	if (!*osc_freq) {
40 		WARN_ON(1);
41 		return -EINVAL;
42 	}
43 
44 	osc = clk_register_fixed_rate(NULL, "osc", NULL, 0, *osc_freq);
45 
46 	dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m, clks);
47 	if (!dt_clk)
48 		return 0;
49 
50 	clk = clk_register_fixed_factor(NULL, "clk_m", "osc",
51 					0, 1, clk_m_div);
52 	*dt_clk = clk;
53 
54 	/* pll_ref */
55 	val = (val >> OSC_CTRL_PLL_REF_DIV_SHIFT) & 3;
56 	pll_ref_div = 1 << val;
57 	dt_clk = tegra_lookup_dt_id(tegra_clk_pll_ref, clks);
58 	if (!dt_clk)
59 		return 0;
60 
61 	clk = clk_register_fixed_factor(NULL, "pll_ref", "osc",
62 					0, 1, pll_ref_div);
63 	*dt_clk = clk;
64 
65 	if (pll_ref_freq)
66 		*pll_ref_freq = *osc_freq / pll_ref_div;
67 
68 	return 0;
69 }
70 
71 void __init tegra_fixed_clk_init(struct tegra_clk *tegra_clks)
72 {
73 	struct clk *clk;
74 	struct clk **dt_clk;
75 
76 	/* clk_32k */
77 	dt_clk = tegra_lookup_dt_id(tegra_clk_clk_32k, tegra_clks);
78 	if (dt_clk) {
79 		clk = clk_register_fixed_rate(NULL, "clk_32k", NULL, 0, 32768);
80 		*dt_clk = clk;
81 	}
82 
83 	/* clk_m_div2 */
84 	dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m_div2, tegra_clks);
85 	if (dt_clk) {
86 		clk = clk_register_fixed_factor(NULL, "clk_m_div2", "clk_m",
87 					CLK_SET_RATE_PARENT, 1, 2);
88 		*dt_clk = clk;
89 	}
90 
91 	/* clk_m_div4 */
92 	dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m_div4, tegra_clks);
93 	if (dt_clk) {
94 		clk = clk_register_fixed_factor(NULL, "clk_m_div4", "clk_m",
95 					CLK_SET_RATE_PARENT, 1, 4);
96 		*dt_clk = clk;
97 	}
98 }
99