1/*
2 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
3 * Author: Tomasz Figa <t.figa@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 * Clock driver for Exynos clock output
10 */
11
12#include <linux/slab.h>
13#include <linux/clk.h>
14#include <linux/clk-provider.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/syscore_ops.h>
18
19#define EXYNOS_CLKOUT_NR_CLKS		1
20#define EXYNOS_CLKOUT_PARENTS		32
21
22#define EXYNOS_PMU_DEBUG_REG		0xa00
23#define EXYNOS_CLKOUT_DISABLE_SHIFT	0
24#define EXYNOS_CLKOUT_MUX_SHIFT		8
25#define EXYNOS4_CLKOUT_MUX_MASK		0xf
26#define EXYNOS5_CLKOUT_MUX_MASK		0x1f
27
28struct exynos_clkout {
29	struct clk_gate gate;
30	struct clk_mux mux;
31	spinlock_t slock;
32	struct clk_onecell_data data;
33	struct clk *clk_table[EXYNOS_CLKOUT_NR_CLKS];
34	void __iomem *reg;
35	u32 pmu_debug_save;
36};
37
38static struct exynos_clkout *clkout;
39
40static int exynos_clkout_suspend(void)
41{
42	clkout->pmu_debug_save = readl(clkout->reg + EXYNOS_PMU_DEBUG_REG);
43
44	return 0;
45}
46
47static void exynos_clkout_resume(void)
48{
49	writel(clkout->pmu_debug_save, clkout->reg + EXYNOS_PMU_DEBUG_REG);
50}
51
52static struct syscore_ops exynos_clkout_syscore_ops = {
53	.suspend = exynos_clkout_suspend,
54	.resume = exynos_clkout_resume,
55};
56
57static void __init exynos_clkout_init(struct device_node *node, u32 mux_mask)
58{
59	const char *parent_names[EXYNOS_CLKOUT_PARENTS];
60	struct clk *parents[EXYNOS_CLKOUT_PARENTS];
61	int parent_count;
62	int ret;
63	int i;
64
65	clkout = kzalloc(sizeof(*clkout), GFP_KERNEL);
66	if (!clkout)
67		return;
68
69	spin_lock_init(&clkout->slock);
70
71	parent_count = 0;
72	for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i) {
73		char name[] = "clkoutXX";
74
75		snprintf(name, sizeof(name), "clkout%d", i);
76		parents[i] = of_clk_get_by_name(node, name);
77		if (IS_ERR(parents[i])) {
78			parent_names[i] = "none";
79			continue;
80		}
81
82		parent_names[i] = __clk_get_name(parents[i]);
83		parent_count = i + 1;
84	}
85
86	if (!parent_count)
87		goto free_clkout;
88
89	clkout->reg = of_iomap(node, 0);
90	if (!clkout->reg)
91		goto clks_put;
92
93	clkout->gate.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG;
94	clkout->gate.bit_idx = EXYNOS_CLKOUT_DISABLE_SHIFT;
95	clkout->gate.flags = CLK_GATE_SET_TO_DISABLE;
96	clkout->gate.lock = &clkout->slock;
97
98	clkout->mux.reg = clkout->reg + EXYNOS_PMU_DEBUG_REG;
99	clkout->mux.mask = mux_mask;
100	clkout->mux.shift = EXYNOS_CLKOUT_MUX_SHIFT;
101	clkout->mux.lock = &clkout->slock;
102
103	clkout->clk_table[0] = clk_register_composite(NULL, "clkout",
104				parent_names, parent_count, &clkout->mux.hw,
105				&clk_mux_ops, NULL, NULL, &clkout->gate.hw,
106				&clk_gate_ops, CLK_SET_RATE_PARENT
107				| CLK_SET_RATE_NO_REPARENT);
108	if (IS_ERR(clkout->clk_table[0]))
109		goto err_unmap;
110
111	clkout->data.clks = clkout->clk_table;
112	clkout->data.clk_num = EXYNOS_CLKOUT_NR_CLKS;
113	ret = of_clk_add_provider(node, of_clk_src_onecell_get, &clkout->data);
114	if (ret)
115		goto err_clk_unreg;
116
117	register_syscore_ops(&exynos_clkout_syscore_ops);
118
119	return;
120
121err_clk_unreg:
122	clk_unregister(clkout->clk_table[0]);
123err_unmap:
124	iounmap(clkout->reg);
125clks_put:
126	for (i = 0; i < EXYNOS_CLKOUT_PARENTS; ++i)
127		if (!IS_ERR(parents[i]))
128			clk_put(parents[i]);
129free_clkout:
130	kfree(clkout);
131
132	pr_err("%s: failed to register clkout clock\n", __func__);
133}
134
135static void __init exynos4_clkout_init(struct device_node *node)
136{
137	exynos_clkout_init(node, EXYNOS4_CLKOUT_MUX_MASK);
138}
139CLK_OF_DECLARE(exynos4210_clkout, "samsung,exynos4210-pmu",
140		exynos4_clkout_init);
141CLK_OF_DECLARE(exynos4212_clkout, "samsung,exynos4212-pmu",
142		exynos4_clkout_init);
143CLK_OF_DECLARE(exynos4412_clkout, "samsung,exynos4412-pmu",
144		exynos4_clkout_init);
145CLK_OF_DECLARE(exynos3250_clkout, "samsung,exynos3250-pmu",
146		exynos4_clkout_init);
147
148static void __init exynos5_clkout_init(struct device_node *node)
149{
150	exynos_clkout_init(node, EXYNOS5_CLKOUT_MUX_MASK);
151}
152CLK_OF_DECLARE(exynos5250_clkout, "samsung,exynos5250-pmu",
153		exynos5_clkout_init);
154CLK_OF_DECLARE(exynos5420_clkout, "samsung,exynos5420-pmu",
155		exynos5_clkout_init);
156CLK_OF_DECLARE(exynos5433_clkout, "samsung,exynos5433-pmu",
157		exynos5_clkout_init);
158