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14#include <linux/amba/sp810.h>
15#include <linux/clkdev.h>
16#include <linux/clk-provider.h>
17#include <linux/err.h>
18#include <linux/of.h>
19#include <linux/of_address.h>
20
21#define to_clk_sp810_timerclken(_hw) \
22 container_of(_hw, struct clk_sp810_timerclken, hw)
23
24struct clk_sp810;
25
26struct clk_sp810_timerclken {
27 struct clk_hw hw;
28 struct clk *clk;
29 struct clk_sp810 *sp810;
30 int channel;
31};
32
33struct clk_sp810 {
34 struct device_node *node;
35 int refclk_index, timclk_index;
36 void __iomem *base;
37 spinlock_t lock;
38 struct clk_sp810_timerclken timerclken[4];
39 struct clk *refclk;
40 struct clk *timclk;
41};
42
43static u8 clk_sp810_timerclken_get_parent(struct clk_hw *hw)
44{
45 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
46 u32 val = readl(timerclken->sp810->base + SCCTRL);
47
48 return !!(val & (1 << SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel)));
49}
50
51static int clk_sp810_timerclken_set_parent(struct clk_hw *hw, u8 index)
52{
53 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
54 struct clk_sp810 *sp810 = timerclken->sp810;
55 u32 val, shift = SCCTRL_TIMERENnSEL_SHIFT(timerclken->channel);
56 unsigned long flags = 0;
57
58 if (WARN_ON(index > 1))
59 return -EINVAL;
60
61 spin_lock_irqsave(&sp810->lock, flags);
62
63 val = readl(sp810->base + SCCTRL);
64 val &= ~(1 << shift);
65 val |= index << shift;
66 writel(val, sp810->base + SCCTRL);
67
68 spin_unlock_irqrestore(&sp810->lock, flags);
69
70 return 0;
71}
72
73
74
75
76
77
78static int clk_sp810_timerclken_prepare(struct clk_hw *hw)
79{
80 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
81 struct clk_sp810 *sp810 = timerclken->sp810;
82 struct clk *old_parent = __clk_get_parent(hw->clk);
83 struct clk *new_parent;
84
85 if (!sp810->refclk)
86 sp810->refclk = of_clk_get(sp810->node, sp810->refclk_index);
87
88 if (!sp810->timclk)
89 sp810->timclk = of_clk_get(sp810->node, sp810->timclk_index);
90
91 if (WARN_ON(IS_ERR(sp810->refclk) || IS_ERR(sp810->timclk)))
92 return -ENOENT;
93
94
95 if (clk_get_rate(sp810->refclk) > clk_get_rate(sp810->timclk))
96 new_parent = sp810->refclk;
97 else
98 new_parent = sp810->timclk;
99
100
101 if (old_parent != new_parent) {
102 clk_prepare(new_parent);
103 clk_set_parent(hw->clk, new_parent);
104 clk_unprepare(old_parent);
105 }
106
107 return 0;
108}
109
110static void clk_sp810_timerclken_unprepare(struct clk_hw *hw)
111{
112 struct clk_sp810_timerclken *timerclken = to_clk_sp810_timerclken(hw);
113 struct clk_sp810 *sp810 = timerclken->sp810;
114
115 clk_put(sp810->timclk);
116 clk_put(sp810->refclk);
117}
118
119static const struct clk_ops clk_sp810_timerclken_ops = {
120 .prepare = clk_sp810_timerclken_prepare,
121 .unprepare = clk_sp810_timerclken_unprepare,
122 .get_parent = clk_sp810_timerclken_get_parent,
123 .set_parent = clk_sp810_timerclken_set_parent,
124};
125
126static struct clk *clk_sp810_timerclken_of_get(struct of_phandle_args *clkspec,
127 void *data)
128{
129 struct clk_sp810 *sp810 = data;
130
131 if (WARN_ON(clkspec->args_count != 1 || clkspec->args[0] >
132 ARRAY_SIZE(sp810->timerclken)))
133 return NULL;
134
135 return sp810->timerclken[clkspec->args[0]].clk;
136}
137
138void __init clk_sp810_of_setup(struct device_node *node)
139{
140 struct clk_sp810 *sp810 = kzalloc(sizeof(*sp810), GFP_KERNEL);
141 const char *parent_names[2];
142 char name[12];
143 struct clk_init_data init;
144 int i;
145
146 if (!sp810) {
147 pr_err("Failed to allocate memory for SP810!\n");
148 return;
149 }
150
151 sp810->refclk_index = of_property_match_string(node, "clock-names",
152 "refclk");
153 parent_names[0] = of_clk_get_parent_name(node, sp810->refclk_index);
154
155 sp810->timclk_index = of_property_match_string(node, "clock-names",
156 "timclk");
157 parent_names[1] = of_clk_get_parent_name(node, sp810->timclk_index);
158
159 if (parent_names[0] <= 0 || parent_names[1] <= 0) {
160 pr_warn("Failed to obtain parent clocks for SP810!\n");
161 return;
162 }
163
164 sp810->node = node;
165 sp810->base = of_iomap(node, 0);
166 spin_lock_init(&sp810->lock);
167
168 init.name = name;
169 init.ops = &clk_sp810_timerclken_ops;
170 init.flags = CLK_IS_BASIC;
171 init.parent_names = parent_names;
172 init.num_parents = ARRAY_SIZE(parent_names);
173
174 for (i = 0; i < ARRAY_SIZE(sp810->timerclken); i++) {
175 snprintf(name, ARRAY_SIZE(name), "timerclken%d", i);
176
177 sp810->timerclken[i].sp810 = sp810;
178 sp810->timerclken[i].channel = i;
179 sp810->timerclken[i].hw.init = &init;
180
181 sp810->timerclken[i].clk = clk_register(NULL,
182 &sp810->timerclken[i].hw);
183 WARN_ON(IS_ERR(sp810->timerclken[i].clk));
184 }
185
186 of_clk_add_provider(node, clk_sp810_timerclken_of_get, sp810);
187}
188CLK_OF_DECLARE(sp810, "arm,sp810", clk_sp810_of_setup);
189
