xref: /openbmc/linux/drivers/clk/actions/owl-pll.c (revision bab79506)
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, &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, &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, &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