xref: /openbmc/linux/drivers/clk/rockchip/clk.c (revision 275876e2)
1 /*
2  * Copyright (c) 2014 MundoReader S.L.
3  * Author: Heiko Stuebner <heiko@sntech.de>
4  *
5  * based on
6  *
7  * samsung/clk.c
8  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
9  * Copyright (c) 2013 Linaro Ltd.
10  * Author: Thomas Abraham <thomas.ab@samsung.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/clk.h>
25 #include <linux/clk-provider.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/regmap.h>
28 #include "clk.h"
29 
30 /**
31  * Register a clock branch.
32  * Most clock branches have a form like
33  *
34  * src1 --|--\
35  *        |M |--[GATE]-[DIV]-
36  * src2 --|--/
37  *
38  * sometimes without one of those components.
39  */
40 struct clk *rockchip_clk_register_branch(const char *name,
41 		const char **parent_names, u8 num_parents, void __iomem *base,
42 		int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
43 		u8 div_shift, u8 div_width, u8 div_flags,
44 		struct clk_div_table *div_table, int gate_offset,
45 		u8 gate_shift, u8 gate_flags, unsigned long flags,
46 		spinlock_t *lock)
47 {
48 	struct clk *clk;
49 	struct clk_mux *mux = NULL;
50 	struct clk_gate *gate = NULL;
51 	struct clk_divider *div = NULL;
52 	const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
53 			     *gate_ops = NULL;
54 
55 	if (num_parents > 1) {
56 		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
57 		if (!mux)
58 			return ERR_PTR(-ENOMEM);
59 
60 		mux->reg = base + muxdiv_offset;
61 		mux->shift = mux_shift;
62 		mux->mask = BIT(mux_width) - 1;
63 		mux->flags = mux_flags;
64 		mux->lock = lock;
65 		mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
66 							: &clk_mux_ops;
67 	}
68 
69 	if (gate_offset >= 0) {
70 		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
71 		if (!gate)
72 			return ERR_PTR(-ENOMEM);
73 
74 		gate->flags = gate_flags;
75 		gate->reg = base + gate_offset;
76 		gate->bit_idx = gate_shift;
77 		gate->lock = lock;
78 		gate_ops = &clk_gate_ops;
79 	}
80 
81 	if (div_width > 0) {
82 		div = kzalloc(sizeof(*div), GFP_KERNEL);
83 		if (!div)
84 			return ERR_PTR(-ENOMEM);
85 
86 		div->flags = div_flags;
87 		div->reg = base + muxdiv_offset;
88 		div->shift = div_shift;
89 		div->width = div_width;
90 		div->lock = lock;
91 		div->table = div_table;
92 		div_ops = (div_flags & CLK_DIVIDER_READ_ONLY)
93 						? &clk_divider_ro_ops
94 						: &clk_divider_ops;
95 	}
96 
97 	clk = clk_register_composite(NULL, name, parent_names, num_parents,
98 				     mux ? &mux->hw : NULL, mux_ops,
99 				     div ? &div->hw : NULL, div_ops,
100 				     gate ? &gate->hw : NULL, gate_ops,
101 				     flags);
102 
103 	return clk;
104 }
105 
106 static DEFINE_SPINLOCK(clk_lock);
107 static struct clk **clk_table;
108 static void __iomem *reg_base;
109 static struct clk_onecell_data clk_data;
110 static struct device_node *cru_node;
111 static struct regmap *grf;
112 
113 void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
114 			      unsigned long nr_clks)
115 {
116 	reg_base = base;
117 	cru_node = np;
118 	grf = ERR_PTR(-EPROBE_DEFER);
119 
120 	clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
121 	if (!clk_table)
122 		pr_err("%s: could not allocate clock lookup table\n", __func__);
123 
124 	clk_data.clks = clk_table;
125 	clk_data.clk_num = nr_clks;
126 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
127 }
128 
129 struct regmap *rockchip_clk_get_grf(void)
130 {
131 	if (IS_ERR(grf))
132 		grf = syscon_regmap_lookup_by_phandle(cru_node, "rockchip,grf");
133 	return grf;
134 }
135 
136 void rockchip_clk_add_lookup(struct clk *clk, unsigned int id)
137 {
138 	if (clk_table && id)
139 		clk_table[id] = clk;
140 }
141 
142 void __init rockchip_clk_register_plls(struct rockchip_pll_clock *list,
143 				unsigned int nr_pll, int grf_lock_offset)
144 {
145 	struct clk *clk;
146 	int idx;
147 
148 	for (idx = 0; idx < nr_pll; idx++, list++) {
149 		clk = rockchip_clk_register_pll(list->type, list->name,
150 				list->parent_names, list->num_parents,
151 				reg_base, list->con_offset, grf_lock_offset,
152 				list->lock_shift, list->mode_offset,
153 				list->mode_shift, list->rate_table, &clk_lock);
154 		if (IS_ERR(clk)) {
155 			pr_err("%s: failed to register clock %s\n", __func__,
156 				list->name);
157 			continue;
158 		}
159 
160 		rockchip_clk_add_lookup(clk, list->id);
161 	}
162 }
163 
164 void __init rockchip_clk_register_branches(
165 				      struct rockchip_clk_branch *list,
166 				      unsigned int nr_clk)
167 {
168 	struct clk *clk = NULL;
169 	unsigned int idx;
170 	unsigned long flags;
171 
172 	for (idx = 0; idx < nr_clk; idx++, list++) {
173 		flags = list->flags;
174 
175 		/* catch simple muxes */
176 		switch (list->branch_type) {
177 		case branch_mux:
178 			clk = clk_register_mux(NULL, list->name,
179 				list->parent_names, list->num_parents,
180 				flags, reg_base + list->muxdiv_offset,
181 				list->mux_shift, list->mux_width,
182 				list->mux_flags, &clk_lock);
183 			break;
184 		case branch_divider:
185 			if (list->div_table)
186 				clk = clk_register_divider_table(NULL,
187 					list->name, list->parent_names[0],
188 					flags, reg_base + list->muxdiv_offset,
189 					list->div_shift, list->div_width,
190 					list->div_flags, list->div_table,
191 					&clk_lock);
192 			else
193 				clk = clk_register_divider(NULL, list->name,
194 					list->parent_names[0], flags,
195 					reg_base + list->muxdiv_offset,
196 					list->div_shift, list->div_width,
197 					list->div_flags, &clk_lock);
198 			break;
199 		case branch_fraction_divider:
200 			/* unimplemented */
201 			continue;
202 			break;
203 		case branch_gate:
204 			flags |= CLK_SET_RATE_PARENT;
205 
206 			/* keep all gates untouched for now */
207 			flags |= CLK_IGNORE_UNUSED;
208 
209 			clk = clk_register_gate(NULL, list->name,
210 				list->parent_names[0], flags,
211 				reg_base + list->gate_offset,
212 				list->gate_shift, list->gate_flags, &clk_lock);
213 			break;
214 		case branch_composite:
215 			/* keep all gates untouched for now */
216 			flags |= CLK_IGNORE_UNUSED;
217 
218 			clk = rockchip_clk_register_branch(list->name,
219 				list->parent_names, list->num_parents,
220 				reg_base, list->muxdiv_offset, list->mux_shift,
221 				list->mux_width, list->mux_flags,
222 				list->div_shift, list->div_width,
223 				list->div_flags, list->div_table,
224 				list->gate_offset, list->gate_shift,
225 				list->gate_flags, flags, &clk_lock);
226 			break;
227 		}
228 
229 		/* none of the cases above matched */
230 		if (!clk) {
231 			pr_err("%s: unknown clock type %d\n",
232 			       __func__, list->branch_type);
233 			continue;
234 		}
235 
236 		if (IS_ERR(clk)) {
237 			pr_err("%s: failed to register clock %s: %ld\n",
238 			       __func__, list->name, PTR_ERR(clk));
239 			continue;
240 		}
241 
242 		rockchip_clk_add_lookup(clk, list->id);
243 	}
244 }
245