1 /*
2  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
3  * Author: Padmavathi Venna <padma.v@samsung.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Common Clock Framework support for Audio Subsystem Clock Controller.
10 */
11 
12 #include <linux/clkdev.h>
13 #include <linux/io.h>
14 #include <linux/clk-provider.h>
15 #include <linux/of_address.h>
16 #include <linux/syscore_ops.h>
17 
18 #include <dt-bindings/clk/exynos-audss-clk.h>
19 
20 static DEFINE_SPINLOCK(lock);
21 static struct clk **clk_table;
22 static void __iomem *reg_base;
23 static struct clk_onecell_data clk_data;
24 
25 #define ASS_CLK_SRC 0x0
26 #define ASS_CLK_DIV 0x4
27 #define ASS_CLK_GATE 0x8
28 
29 static unsigned long reg_save[][2] = {
30 	{ASS_CLK_SRC,  0},
31 	{ASS_CLK_DIV,  0},
32 	{ASS_CLK_GATE, 0},
33 };
34 
35 /* list of all parent clock list */
36 static const char *mout_audss_p[] = { "fin_pll", "fout_epll" };
37 static const char *mout_i2s_p[] = { "mout_audss", "cdclk0", "sclk_audio0" };
38 
39 #ifdef CONFIG_PM_SLEEP
40 static int exynos_audss_clk_suspend(void)
41 {
42 	int i;
43 
44 	for (i = 0; i < ARRAY_SIZE(reg_save); i++)
45 		reg_save[i][1] = readl(reg_base + reg_save[i][0]);
46 
47 	return 0;
48 }
49 
50 static void exynos_audss_clk_resume(void)
51 {
52 	int i;
53 
54 	for (i = 0; i < ARRAY_SIZE(reg_save); i++)
55 		writel(reg_save[i][1], reg_base + reg_save[i][0]);
56 }
57 
58 static struct syscore_ops exynos_audss_clk_syscore_ops = {
59 	.suspend	= exynos_audss_clk_suspend,
60 	.resume		= exynos_audss_clk_resume,
61 };
62 #endif /* CONFIG_PM_SLEEP */
63 
64 /* register exynos_audss clocks */
65 static void __init exynos_audss_clk_init(struct device_node *np)
66 {
67 	reg_base = of_iomap(np, 0);
68 	if (!reg_base) {
69 		pr_err("%s: failed to map audss registers\n", __func__);
70 		return;
71 	}
72 
73 	clk_table = kzalloc(sizeof(struct clk *) * EXYNOS_AUDSS_MAX_CLKS,
74 				GFP_KERNEL);
75 	if (!clk_table) {
76 		pr_err("%s: could not allocate clk lookup table\n", __func__);
77 		return;
78 	}
79 
80 	clk_data.clks = clk_table;
81 	clk_data.clk_num = EXYNOS_AUDSS_MAX_CLKS;
82 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
83 
84 	clk_table[EXYNOS_MOUT_AUDSS] = clk_register_mux(NULL, "mout_audss",
85 				mout_audss_p, ARRAY_SIZE(mout_audss_p),
86 				CLK_SET_RATE_NO_REPARENT,
87 				reg_base + ASS_CLK_SRC, 0, 1, 0, &lock);
88 
89 	clk_table[EXYNOS_MOUT_I2S] = clk_register_mux(NULL, "mout_i2s",
90 				mout_i2s_p, ARRAY_SIZE(mout_i2s_p),
91 				CLK_SET_RATE_NO_REPARENT,
92 				reg_base + ASS_CLK_SRC, 2, 2, 0, &lock);
93 
94 	clk_table[EXYNOS_DOUT_SRP] = clk_register_divider(NULL, "dout_srp",
95 				"mout_audss", 0, reg_base + ASS_CLK_DIV, 0, 4,
96 				0, &lock);
97 
98 	clk_table[EXYNOS_DOUT_AUD_BUS] = clk_register_divider(NULL,
99 				"dout_aud_bus", "dout_srp", 0,
100 				reg_base + ASS_CLK_DIV, 4, 4, 0, &lock);
101 
102 	clk_table[EXYNOS_DOUT_I2S] = clk_register_divider(NULL, "dout_i2s",
103 				"mout_i2s", 0, reg_base + ASS_CLK_DIV, 8, 4, 0,
104 				&lock);
105 
106 	clk_table[EXYNOS_SRP_CLK] = clk_register_gate(NULL, "srp_clk",
107 				"dout_srp", CLK_SET_RATE_PARENT,
108 				reg_base + ASS_CLK_GATE, 0, 0, &lock);
109 
110 	clk_table[EXYNOS_I2S_BUS] = clk_register_gate(NULL, "i2s_bus",
111 				"dout_aud_bus", CLK_SET_RATE_PARENT,
112 				reg_base + ASS_CLK_GATE, 2, 0, &lock);
113 
114 	clk_table[EXYNOS_SCLK_I2S] = clk_register_gate(NULL, "sclk_i2s",
115 				"dout_i2s", CLK_SET_RATE_PARENT,
116 				reg_base + ASS_CLK_GATE, 3, 0, &lock);
117 
118 	clk_table[EXYNOS_PCM_BUS] = clk_register_gate(NULL, "pcm_bus",
119 				 "sclk_pcm", CLK_SET_RATE_PARENT,
120 				reg_base + ASS_CLK_GATE, 4, 0, &lock);
121 
122 	clk_table[EXYNOS_SCLK_PCM] = clk_register_gate(NULL, "sclk_pcm",
123 				"div_pcm0", CLK_SET_RATE_PARENT,
124 				reg_base + ASS_CLK_GATE, 5, 0, &lock);
125 
126 #ifdef CONFIG_PM_SLEEP
127 	register_syscore_ops(&exynos_audss_clk_syscore_ops);
128 #endif
129 
130 	pr_info("Exynos: Audss: clock setup completed\n");
131 }
132 CLK_OF_DECLARE(exynos4210_audss_clk, "samsung,exynos4210-audss-clock",
133 		exynos_audss_clk_init);
134 CLK_OF_DECLARE(exynos5250_audss_clk, "samsung,exynos5250-audss-clock",
135 		exynos_audss_clk_init);
136