xref: /openbmc/linux/drivers/clk/tegra/clk-periph.c (revision db181ce0)
1 /*
2  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 #include <linux/export.h>
20 #include <linux/slab.h>
21 #include <linux/err.h>
22 
23 #include "clk.h"
24 
25 static u8 clk_periph_get_parent(struct clk_hw *hw)
26 {
27 	struct tegra_clk_periph *periph = to_clk_periph(hw);
28 	const struct clk_ops *mux_ops = periph->mux_ops;
29 	struct clk_hw *mux_hw = &periph->mux.hw;
30 
31 	mux_hw->clk = hw->clk;
32 
33 	return mux_ops->get_parent(mux_hw);
34 }
35 
36 static int clk_periph_set_parent(struct clk_hw *hw, u8 index)
37 {
38 	struct tegra_clk_periph *periph = to_clk_periph(hw);
39 	const struct clk_ops *mux_ops = periph->mux_ops;
40 	struct clk_hw *mux_hw = &periph->mux.hw;
41 
42 	mux_hw->clk = hw->clk;
43 
44 	return mux_ops->set_parent(mux_hw, index);
45 }
46 
47 static unsigned long clk_periph_recalc_rate(struct clk_hw *hw,
48 					    unsigned long parent_rate)
49 {
50 	struct tegra_clk_periph *periph = to_clk_periph(hw);
51 	const struct clk_ops *div_ops = periph->div_ops;
52 	struct clk_hw *div_hw = &periph->divider.hw;
53 
54 	div_hw->clk = hw->clk;
55 
56 	return div_ops->recalc_rate(div_hw, parent_rate);
57 }
58 
59 static long clk_periph_round_rate(struct clk_hw *hw, unsigned long rate,
60 				  unsigned long *prate)
61 {
62 	struct tegra_clk_periph *periph = to_clk_periph(hw);
63 	const struct clk_ops *div_ops = periph->div_ops;
64 	struct clk_hw *div_hw = &periph->divider.hw;
65 
66 	div_hw->clk = hw->clk;
67 
68 	return div_ops->round_rate(div_hw, rate, prate);
69 }
70 
71 static int clk_periph_set_rate(struct clk_hw *hw, unsigned long rate,
72 			       unsigned long parent_rate)
73 {
74 	struct tegra_clk_periph *periph = to_clk_periph(hw);
75 	const struct clk_ops *div_ops = periph->div_ops;
76 	struct clk_hw *div_hw = &periph->divider.hw;
77 
78 	div_hw->clk = hw->clk;
79 
80 	return div_ops->set_rate(div_hw, rate, parent_rate);
81 }
82 
83 static int clk_periph_is_enabled(struct clk_hw *hw)
84 {
85 	struct tegra_clk_periph *periph = to_clk_periph(hw);
86 	const struct clk_ops *gate_ops = periph->gate_ops;
87 	struct clk_hw *gate_hw = &periph->gate.hw;
88 
89 	gate_hw->clk = hw->clk;
90 
91 	return gate_ops->is_enabled(gate_hw);
92 }
93 
94 static int clk_periph_enable(struct clk_hw *hw)
95 {
96 	struct tegra_clk_periph *periph = to_clk_periph(hw);
97 	const struct clk_ops *gate_ops = periph->gate_ops;
98 	struct clk_hw *gate_hw = &periph->gate.hw;
99 
100 	gate_hw->clk = hw->clk;
101 
102 	return gate_ops->enable(gate_hw);
103 }
104 
105 static void clk_periph_disable(struct clk_hw *hw)
106 {
107 	struct tegra_clk_periph *periph = to_clk_periph(hw);
108 	const struct clk_ops *gate_ops = periph->gate_ops;
109 	struct clk_hw *gate_hw = &periph->gate.hw;
110 
111 	gate_ops->disable(gate_hw);
112 }
113 
114 const struct clk_ops tegra_clk_periph_ops = {
115 	.get_parent = clk_periph_get_parent,
116 	.set_parent = clk_periph_set_parent,
117 	.recalc_rate = clk_periph_recalc_rate,
118 	.round_rate = clk_periph_round_rate,
119 	.set_rate = clk_periph_set_rate,
120 	.is_enabled = clk_periph_is_enabled,
121 	.enable = clk_periph_enable,
122 	.disable = clk_periph_disable,
123 };
124 
125 static const struct clk_ops tegra_clk_periph_nodiv_ops = {
126 	.get_parent = clk_periph_get_parent,
127 	.set_parent = clk_periph_set_parent,
128 	.is_enabled = clk_periph_is_enabled,
129 	.enable = clk_periph_enable,
130 	.disable = clk_periph_disable,
131 };
132 
133 static const struct clk_ops tegra_clk_periph_no_gate_ops = {
134 	.get_parent = clk_periph_get_parent,
135 	.set_parent = clk_periph_set_parent,
136 	.recalc_rate = clk_periph_recalc_rate,
137 	.round_rate = clk_periph_round_rate,
138 	.set_rate = clk_periph_set_rate,
139 };
140 
141 static struct clk *_tegra_clk_register_periph(const char *name,
142 			const char **parent_names, int num_parents,
143 			struct tegra_clk_periph *periph,
144 			void __iomem *clk_base, u32 offset,
145 			unsigned long flags)
146 {
147 	struct clk *clk;
148 	struct clk_init_data init;
149 	struct tegra_clk_periph_regs *bank;
150 	bool div = !(periph->gate.flags & TEGRA_PERIPH_NO_DIV);
151 
152 	if (periph->gate.flags & TEGRA_PERIPH_NO_DIV) {
153 		flags |= CLK_SET_RATE_PARENT;
154 		init.ops = &tegra_clk_periph_nodiv_ops;
155 	} else if (periph->gate.flags & TEGRA_PERIPH_NO_GATE)
156 		init.ops = &tegra_clk_periph_no_gate_ops;
157 	else
158 		init.ops = &tegra_clk_periph_ops;
159 
160 	init.name = name;
161 	init.flags = flags;
162 	init.parent_names = parent_names;
163 	init.num_parents = num_parents;
164 
165 	bank = get_reg_bank(periph->gate.clk_num);
166 	if (!bank)
167 		return ERR_PTR(-EINVAL);
168 
169 	/* Data in .init is copied by clk_register(), so stack variable OK */
170 	periph->hw.init = &init;
171 	periph->magic = TEGRA_CLK_PERIPH_MAGIC;
172 	periph->mux.reg = clk_base + offset;
173 	periph->divider.reg = div ? (clk_base + offset) : NULL;
174 	periph->gate.clk_base = clk_base;
175 	periph->gate.regs = bank;
176 	periph->gate.enable_refcnt = periph_clk_enb_refcnt;
177 
178 	clk = clk_register(NULL, &periph->hw);
179 	if (IS_ERR(clk))
180 		return clk;
181 
182 	periph->mux.hw.clk = clk;
183 	periph->divider.hw.clk = div ? clk : NULL;
184 	periph->gate.hw.clk = clk;
185 
186 	return clk;
187 }
188 
189 struct clk *tegra_clk_register_periph(const char *name,
190 		const char **parent_names, int num_parents,
191 		struct tegra_clk_periph *periph, void __iomem *clk_base,
192 		u32 offset, unsigned long flags)
193 {
194 	return _tegra_clk_register_periph(name, parent_names, num_parents,
195 			periph, clk_base, offset, flags);
196 }
197 
198 struct clk *tegra_clk_register_periph_nodiv(const char *name,
199 		const char **parent_names, int num_parents,
200 		struct tegra_clk_periph *periph, void __iomem *clk_base,
201 		u32 offset)
202 {
203 	periph->gate.flags |= TEGRA_PERIPH_NO_DIV;
204 	return _tegra_clk_register_periph(name, parent_names, num_parents,
205 			periph, clk_base, offset, CLK_SET_RATE_PARENT);
206 }
207