1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018, The Linux Foundation. All rights reserved.
3
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/io.h>
8 #include <linux/delay.h>
9 #include <linux/err.h>
10 #include <linux/clk-provider.h>
11 #include <linux/spinlock.h>
12
13 #include <asm/krait-l2-accessors.h>
14
15 #include "clk-krait.h"
16
17 /* Secondary and primary muxes share the same cp15 register */
18 static DEFINE_SPINLOCK(krait_clock_reg_lock);
19
20 #define LPL_SHIFT 8
__krait_mux_set_sel(struct krait_mux_clk * mux,int sel)21 static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
22 {
23 unsigned long flags;
24 u32 regval;
25
26 spin_lock_irqsave(&krait_clock_reg_lock, flags);
27 regval = krait_get_l2_indirect_reg(mux->offset);
28 regval &= ~(mux->mask << mux->shift);
29 regval |= (sel & mux->mask) << mux->shift;
30 if (mux->lpl) {
31 regval &= ~(mux->mask << (mux->shift + LPL_SHIFT));
32 regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
33 }
34 krait_set_l2_indirect_reg(mux->offset, regval);
35
36 /* Wait for switch to complete. */
37 mb();
38 udelay(1);
39
40 /*
41 * Unlock now to make sure the mux register is not
42 * modified while switching to the new parent.
43 */
44 spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
45 }
46
krait_mux_set_parent(struct clk_hw * hw,u8 index)47 static int krait_mux_set_parent(struct clk_hw *hw, u8 index)
48 {
49 struct krait_mux_clk *mux = to_krait_mux_clk(hw);
50 u32 sel;
51
52 sel = clk_mux_index_to_val(mux->parent_map, 0, index);
53 mux->en_mask = sel;
54 /* Don't touch mux if CPU is off as it won't work */
55 if (__clk_is_enabled(hw->clk))
56 __krait_mux_set_sel(mux, sel);
57
58 mux->reparent = true;
59
60 return 0;
61 }
62
krait_mux_get_parent(struct clk_hw * hw)63 static u8 krait_mux_get_parent(struct clk_hw *hw)
64 {
65 struct krait_mux_clk *mux = to_krait_mux_clk(hw);
66 u32 sel;
67
68 sel = krait_get_l2_indirect_reg(mux->offset);
69 sel >>= mux->shift;
70 sel &= mux->mask;
71 mux->en_mask = sel;
72
73 return clk_mux_val_to_index(hw, mux->parent_map, 0, sel);
74 }
75
76 const struct clk_ops krait_mux_clk_ops = {
77 .set_parent = krait_mux_set_parent,
78 .get_parent = krait_mux_get_parent,
79 .determine_rate = __clk_mux_determine_rate_closest,
80 };
81 EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
82
83 /* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */
krait_div2_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)84 static long krait_div2_round_rate(struct clk_hw *hw, unsigned long rate,
85 unsigned long *parent_rate)
86 {
87 *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), rate * 2);
88 return DIV_ROUND_UP(*parent_rate, 2);
89 }
90
krait_div2_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)91 static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate,
92 unsigned long parent_rate)
93 {
94 struct krait_div2_clk *d = to_krait_div2_clk(hw);
95 unsigned long flags;
96 u32 val;
97 u32 mask = BIT(d->width) - 1;
98
99 if (d->lpl)
100 mask = mask << (d->shift + LPL_SHIFT) | mask << d->shift;
101 else
102 mask <<= d->shift;
103
104 spin_lock_irqsave(&krait_clock_reg_lock, flags);
105 val = krait_get_l2_indirect_reg(d->offset);
106 val &= ~mask;
107 krait_set_l2_indirect_reg(d->offset, val);
108 spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
109
110 return 0;
111 }
112
113 static unsigned long
krait_div2_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)114 krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
115 {
116 struct krait_div2_clk *d = to_krait_div2_clk(hw);
117 u32 mask = BIT(d->width) - 1;
118 u32 div;
119
120 div = krait_get_l2_indirect_reg(d->offset);
121 div >>= d->shift;
122 div &= mask;
123 div = (div + 1) * 2;
124
125 return DIV_ROUND_UP(parent_rate, div);
126 }
127
128 const struct clk_ops krait_div2_clk_ops = {
129 .round_rate = krait_div2_round_rate,
130 .set_rate = krait_div2_set_rate,
131 .recalc_rate = krait_div2_recalc_rate,
132 };
133 EXPORT_SYMBOL_GPL(krait_div2_clk_ops);
134