1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (c) 2018 Samsung Electronics Co., Ltd.
4 // Author: Marek Szyprowski <m.szyprowski@samsung.com>
5 // Common Clock Framework support for Exynos5 power-domain dependent clocks
6 
7 #include <linux/io.h>
8 #include <linux/of_platform.h>
9 #include <linux/platform_device.h>
10 #include <linux/pm_domain.h>
11 #include <linux/pm_runtime.h>
12 
13 #include "clk.h"
14 #include "clk-exynos5-subcmu.h"
15 
16 static struct samsung_clk_provider *ctx;
17 static const struct exynos5_subcmu_info **cmu;
18 static int nr_cmus;
19 
20 static void exynos5_subcmu_clk_save(void __iomem *base,
21 				    struct exynos5_subcmu_reg_dump *rd,
22 				    unsigned int num_regs)
23 {
24 	for (; num_regs > 0; --num_regs, ++rd) {
25 		rd->save = readl(base + rd->offset);
26 		writel((rd->save & ~rd->mask) | rd->value, base + rd->offset);
27 		rd->save &= rd->mask;
28 	}
29 };
30 
31 static void exynos5_subcmu_clk_restore(void __iomem *base,
32 				       struct exynos5_subcmu_reg_dump *rd,
33 				       unsigned int num_regs)
34 {
35 	for (; num_regs > 0; --num_regs, ++rd)
36 		writel((readl(base + rd->offset) & ~rd->mask) | rd->save,
37 		       base + rd->offset);
38 }
39 
40 static void exynos5_subcmu_defer_gate(struct samsung_clk_provider *ctx,
41 			      const struct samsung_gate_clock *list, int nr_clk)
42 {
43 	while (nr_clk--)
44 		samsung_clk_add_lookup(ctx, ERR_PTR(-EPROBE_DEFER), list++->id);
45 }
46 
47 /*
48  * Pass the needed clock provider context and register sub-CMU clocks
49  *
50  * NOTE: This function has to be called from the main, OF_CLK_DECLARE-
51  * initialized clock provider driver. This happens very early during boot
52  * process. Then this driver, during core_initcall registers two platform
53  * drivers: one which binds to the same device-tree node as OF_CLK_DECLARE
54  * driver and second, for handling its per-domain child-devices. Those
55  * platform drivers are bound to their devices a bit later in arch_initcall,
56  * when OF-core populates all device-tree nodes.
57  */
58 void exynos5_subcmus_init(struct samsung_clk_provider *_ctx, int _nr_cmus,
59 			  const struct exynos5_subcmu_info **_cmu)
60 {
61 	ctx = _ctx;
62 	cmu = _cmu;
63 	nr_cmus = _nr_cmus;
64 
65 	for (; _nr_cmus--; _cmu++) {
66 		exynos5_subcmu_defer_gate(ctx, (*_cmu)->gate_clks,
67 					  (*_cmu)->nr_gate_clks);
68 		exynos5_subcmu_clk_save(ctx->reg_base, (*_cmu)->suspend_regs,
69 					(*_cmu)->nr_suspend_regs);
70 	}
71 }
72 
73 static int __maybe_unused exynos5_subcmu_suspend(struct device *dev)
74 {
75 	struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
76 	unsigned long flags;
77 
78 	spin_lock_irqsave(&ctx->lock, flags);
79 	exynos5_subcmu_clk_save(ctx->reg_base, info->suspend_regs,
80 				info->nr_suspend_regs);
81 	spin_unlock_irqrestore(&ctx->lock, flags);
82 
83 	return 0;
84 }
85 
86 static int __maybe_unused exynos5_subcmu_resume(struct device *dev)
87 {
88 	struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
89 	unsigned long flags;
90 
91 	spin_lock_irqsave(&ctx->lock, flags);
92 	exynos5_subcmu_clk_restore(ctx->reg_base, info->suspend_regs,
93 				   info->nr_suspend_regs);
94 	spin_unlock_irqrestore(&ctx->lock, flags);
95 
96 	return 0;
97 }
98 
99 static int __init exynos5_subcmu_probe(struct platform_device *pdev)
100 {
101 	struct device *dev = &pdev->dev;
102 	struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
103 
104 	pm_runtime_set_suspended(dev);
105 	pm_runtime_enable(dev);
106 	pm_runtime_get(dev);
107 
108 	ctx->dev = dev;
109 	samsung_clk_register_div(ctx, info->div_clks, info->nr_div_clks);
110 	samsung_clk_register_gate(ctx, info->gate_clks, info->nr_gate_clks);
111 	ctx->dev = NULL;
112 
113 	pm_runtime_put_sync(dev);
114 
115 	return 0;
116 }
117 
118 static const struct dev_pm_ops exynos5_subcmu_pm_ops = {
119 	SET_RUNTIME_PM_OPS(exynos5_subcmu_suspend,
120 			   exynos5_subcmu_resume, NULL)
121 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
122 				     pm_runtime_force_resume)
123 };
124 
125 static struct platform_driver exynos5_subcmu_driver __refdata = {
126 	.driver	= {
127 		.name = "exynos5-subcmu",
128 		.suppress_bind_attrs = true,
129 		.pm = &exynos5_subcmu_pm_ops,
130 	},
131 	.probe = exynos5_subcmu_probe,
132 };
133 
134 static int __init exynos5_clk_register_subcmu(struct device *parent,
135 					 const struct exynos5_subcmu_info *info,
136 					      struct device_node *pd_node)
137 {
138 	struct of_phandle_args genpdspec = { .np = pd_node };
139 	struct platform_device *pdev;
140 	int ret;
141 
142 	pdev = platform_device_alloc("exynos5-subcmu", PLATFORM_DEVID_AUTO);
143 	if (!pdev)
144 		return -ENOMEM;
145 
146 	pdev->dev.parent = parent;
147 	platform_set_drvdata(pdev, (void *)info);
148 	of_genpd_add_device(&genpdspec, &pdev->dev);
149 	ret = platform_device_add(pdev);
150 	if (ret)
151 		platform_device_put(pdev);
152 
153 	return ret;
154 }
155 
156 static int __init exynos5_clk_probe(struct platform_device *pdev)
157 {
158 	struct device_node *np;
159 	const char *name;
160 	int i;
161 
162 	for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
163 		if (of_property_read_string(np, "label", &name) < 0)
164 			continue;
165 		for (i = 0; i < nr_cmus; i++)
166 			if (strcmp(cmu[i]->pd_name, name) == 0)
167 				exynos5_clk_register_subcmu(&pdev->dev,
168 							    cmu[i], np);
169 	}
170 	return 0;
171 }
172 
173 static const struct of_device_id exynos5_clk_of_match[] = {
174 	{ .compatible = "samsung,exynos5250-clock", },
175 	{ .compatible = "samsung,exynos5420-clock", },
176 	{ .compatible = "samsung,exynos5800-clock", },
177 	{ },
178 };
179 
180 static struct platform_driver exynos5_clk_driver __refdata = {
181 	.driver	= {
182 		.name = "exynos5-clock",
183 		.of_match_table = exynos5_clk_of_match,
184 		.suppress_bind_attrs = true,
185 	},
186 	.probe = exynos5_clk_probe,
187 };
188 
189 static int __init exynos5_clk_drv_init(void)
190 {
191 	platform_driver_register(&exynos5_clk_driver);
192 	platform_driver_register(&exynos5_subcmu_driver);
193 	return 0;
194 }
195 core_initcall(exynos5_clk_drv_init);
196