1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // OWL pll clock driver
4 //
5 // Copyright (c) 2014 Actions Semi Inc.
6 // Author: David Liu <liuwei@actions-semi.com>
7 //
8 // Copyright (c) 2018 Linaro Ltd.
9 // Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
10
11 #include <linux/clk-provider.h>
12 #include <linux/slab.h>
13 #include <linux/io.h>
14 #include <linux/delay.h>
15
16 #include "owl-pll.h"
17
owl_pll_calculate_mul(struct owl_pll_hw * pll_hw,unsigned long rate)18 static u32 owl_pll_calculate_mul(struct owl_pll_hw *pll_hw, unsigned long rate)
19 {
20 u32 mul;
21
22 mul = DIV_ROUND_CLOSEST(rate, pll_hw->bfreq);
23 if (mul < pll_hw->min_mul)
24 mul = pll_hw->min_mul;
25 else if (mul > pll_hw->max_mul)
26 mul = pll_hw->max_mul;
27
28 return mul &= mul_mask(pll_hw);
29 }
30
_get_table_rate(const struct clk_pll_table * table,unsigned int val)31 static unsigned long _get_table_rate(const struct clk_pll_table *table,
32 unsigned int val)
33 {
34 const struct clk_pll_table *clkt;
35
36 for (clkt = table; clkt->rate; clkt++)
37 if (clkt->val == val)
38 return clkt->rate;
39
40 return 0;
41 }
42
_get_pll_table(const struct clk_pll_table * table,unsigned long rate)43 static const struct clk_pll_table *_get_pll_table(
44 const struct clk_pll_table *table, unsigned long rate)
45 {
46 const struct clk_pll_table *clkt;
47
48 for (clkt = table; clkt->rate; clkt++) {
49 if (clkt->rate == rate) {
50 table = clkt;
51 break;
52 } else if (clkt->rate < rate)
53 table = clkt;
54 }
55
56 return table;
57 }
58
owl_pll_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)59 static long owl_pll_round_rate(struct clk_hw *hw, unsigned long rate,
60 unsigned long *parent_rate)
61 {
62 struct owl_pll *pll = hw_to_owl_pll(hw);
63 struct owl_pll_hw *pll_hw = &pll->pll_hw;
64 const struct clk_pll_table *clkt;
65 u32 mul;
66
67 if (pll_hw->table) {
68 clkt = _get_pll_table(pll_hw->table, rate);
69 return clkt->rate;
70 }
71
72 /* fixed frequency */
73 if (pll_hw->width == 0)
74 return pll_hw->bfreq;
75
76 mul = owl_pll_calculate_mul(pll_hw, rate);
77
78 return pll_hw->bfreq * mul;
79 }
80
owl_pll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)81 static unsigned long owl_pll_recalc_rate(struct clk_hw *hw,
82 unsigned long parent_rate)
83 {
84 struct owl_pll *pll = hw_to_owl_pll(hw);
85 struct owl_pll_hw *pll_hw = &pll->pll_hw;
86 const struct owl_clk_common *common = &pll->common;
87 u32 val;
88
89 if (pll_hw->table) {
90 regmap_read(common->regmap, pll_hw->reg, &val);
91
92 val = val >> pll_hw->shift;
93 val &= mul_mask(pll_hw);
94
95 return _get_table_rate(pll_hw->table, val);
96 }
97
98 /* fixed frequency */
99 if (pll_hw->width == 0)
100 return pll_hw->bfreq;
101
102 regmap_read(common->regmap, pll_hw->reg, &val);
103
104 val = val >> pll_hw->shift;
105 val &= mul_mask(pll_hw);
106
107 return pll_hw->bfreq * val;
108 }
109
owl_pll_is_enabled(struct clk_hw * hw)110 static int owl_pll_is_enabled(struct clk_hw *hw)
111 {
112 struct owl_pll *pll = hw_to_owl_pll(hw);
113 struct owl_pll_hw *pll_hw = &pll->pll_hw;
114 const struct owl_clk_common *common = &pll->common;
115 u32 reg;
116
117 regmap_read(common->regmap, pll_hw->reg, ®);
118
119 return !!(reg & BIT(pll_hw->bit_idx));
120 }
121
owl_pll_set(const struct owl_clk_common * common,const struct owl_pll_hw * pll_hw,bool enable)122 static void owl_pll_set(const struct owl_clk_common *common,
123 const struct owl_pll_hw *pll_hw, bool enable)
124 {
125 u32 reg;
126
127 regmap_read(common->regmap, pll_hw->reg, ®);
128
129 if (enable)
130 reg |= BIT(pll_hw->bit_idx);
131 else
132 reg &= ~BIT(pll_hw->bit_idx);
133
134 regmap_write(common->regmap, pll_hw->reg, reg);
135 }
136
owl_pll_enable(struct clk_hw * hw)137 static int owl_pll_enable(struct clk_hw *hw)
138 {
139 struct owl_pll *pll = hw_to_owl_pll(hw);
140 const struct owl_clk_common *common = &pll->common;
141
142 owl_pll_set(common, &pll->pll_hw, true);
143
144 return 0;
145 }
146
owl_pll_disable(struct clk_hw * hw)147 static void owl_pll_disable(struct clk_hw *hw)
148 {
149 struct owl_pll *pll = hw_to_owl_pll(hw);
150 const struct owl_clk_common *common = &pll->common;
151
152 owl_pll_set(common, &pll->pll_hw, false);
153 }
154
owl_pll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)155 static int owl_pll_set_rate(struct clk_hw *hw, unsigned long rate,
156 unsigned long parent_rate)
157 {
158 struct owl_pll *pll = hw_to_owl_pll(hw);
159 struct owl_pll_hw *pll_hw = &pll->pll_hw;
160 const struct owl_clk_common *common = &pll->common;
161 const struct clk_pll_table *clkt;
162 u32 val, reg;
163
164 /* fixed frequency */
165 if (pll_hw->width == 0)
166 return 0;
167
168 if (pll_hw->table) {
169 clkt = _get_pll_table(pll_hw->table, rate);
170 val = clkt->val;
171 } else {
172 val = owl_pll_calculate_mul(pll_hw, rate);
173 }
174
175 regmap_read(common->regmap, pll_hw->reg, ®);
176
177 reg &= ~mul_mask(pll_hw);
178 reg |= val << pll_hw->shift;
179
180 regmap_write(common->regmap, pll_hw->reg, reg);
181
182 udelay(pll_hw->delay);
183
184 return 0;
185 }
186
187 const struct clk_ops owl_pll_ops = {
188 .enable = owl_pll_enable,
189 .disable = owl_pll_disable,
190 .is_enabled = owl_pll_is_enabled,
191 .round_rate = owl_pll_round_rate,
192 .recalc_rate = owl_pll_recalc_rate,
193 .set_rate = owl_pll_set_rate,
194 };
195