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 */
18static DEFINE_SPINLOCK(krait_clock_reg_lock);
19
20#define LPL_SHIFT 8
21#define SECCLKAGD BIT(4)
22
23static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
24{
25 unsigned long flags;
26 u32 regval;
27
28 spin_lock_irqsave(&krait_clock_reg_lock, flags);
29
30 regval = krait_get_l2_indirect_reg(mux->offset);
31
32 /* apq/ipq8064 Errata: disable sec_src clock gating during switch. */
33 if (mux->disable_sec_src_gating) {
34 regval |= SECCLKAGD;
35 krait_set_l2_indirect_reg(mux->offset, regval);
36 }
37
38 regval &= ~(mux->mask << mux->shift);
39 regval |= (sel & mux->mask) << mux->shift;
40 if (mux->lpl) {
41 regval &= ~(mux->mask << (mux->shift + LPL_SHIFT));
42 regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
43 }
44 krait_set_l2_indirect_reg(mux->offset, regval);
45
46 /* apq/ipq8064 Errata: re-enabled sec_src clock gating. */
47 if (mux->disable_sec_src_gating) {
48 regval &= ~SECCLKAGD;
49 krait_set_l2_indirect_reg(mux->offset, regval);
50 }
51
52 /* Wait for switch to complete. */
53 mb();
54 udelay(usec: 1);
55
56 /*
57 * Unlock now to make sure the mux register is not
58 * modified while switching to the new parent.
59 */
60 spin_unlock_irqrestore(lock: &krait_clock_reg_lock, flags);
61}
62
63static int krait_mux_set_parent(struct clk_hw *hw, u8 index)
64{
65 struct krait_mux_clk *mux = to_krait_mux_clk(hw);
66 u32 sel;
67
68 sel = clk_mux_index_to_val(table: mux->parent_map, flags: 0, index);
69 mux->en_mask = sel;
70 /* Don't touch mux if CPU is off as it won't work */
71 if (__clk_is_enabled(clk: hw->clk))
72 __krait_mux_set_sel(mux, sel);
73
74 mux->reparent = true;
75
76 return 0;
77}
78
79static u8 krait_mux_get_parent(struct clk_hw *hw)
80{
81 struct krait_mux_clk *mux = to_krait_mux_clk(hw);
82 u32 sel;
83
84 sel = krait_get_l2_indirect_reg(mux->offset);
85 sel >>= mux->shift;
86 sel &= mux->mask;
87 mux->en_mask = sel;
88
89 return clk_mux_val_to_index(hw, table: mux->parent_map, flags: 0, val: sel);
90}
91
92const struct clk_ops krait_mux_clk_ops = {
93 .set_parent = krait_mux_set_parent,
94 .get_parent = krait_mux_get_parent,
95 .determine_rate = __clk_mux_determine_rate_closest,
96};
97EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
98
99/* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */
100static int krait_div2_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
101{
102 req->best_parent_rate = clk_hw_round_rate(hw: clk_hw_get_parent(hw), rate: req->rate * 2);
103 req->rate = DIV_ROUND_UP(req->best_parent_rate, 2);
104 return 0;
105}
106
107static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate,
108 unsigned long parent_rate)
109{
110 struct krait_div2_clk *d = to_krait_div2_clk(hw);
111 unsigned long flags;
112 u32 val;
113 u32 mask = BIT(d->width) - 1;
114
115 if (d->lpl)
116 mask = mask << (d->shift + LPL_SHIFT) | mask << d->shift;
117 else
118 mask <<= d->shift;
119
120 spin_lock_irqsave(&krait_clock_reg_lock, flags);
121 val = krait_get_l2_indirect_reg(d->offset);
122 val &= ~mask;
123 krait_set_l2_indirect_reg(d->offset, val);
124 spin_unlock_irqrestore(lock: &krait_clock_reg_lock, flags);
125
126 return 0;
127}
128
129static unsigned long
130krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
131{
132 struct krait_div2_clk *d = to_krait_div2_clk(hw);
133 u32 mask = BIT(d->width) - 1;
134 u32 div;
135
136 div = krait_get_l2_indirect_reg(d->offset);
137 div >>= d->shift;
138 div &= mask;
139 div = (div + 1) * 2;
140
141 return DIV_ROUND_UP(parent_rate, div);
142}
143
144const struct clk_ops krait_div2_clk_ops = {
145 .determine_rate = krait_div2_determine_rate,
146 .set_rate = krait_div2_set_rate,
147 .recalc_rate = krait_div2_recalc_rate,
148};
149EXPORT_SYMBOL_GPL(krait_div2_clk_ops);
150

source code of linux/drivers/clk/qcom/clk-krait.c