1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI composite clock support
4 *
5 * Copyright (C) 2013 Texas Instruments, Inc.
6 *
7 * Tero Kristo <t-kristo@ti.com>
8 */
9
10 #include <linux/clk-provider.h>
11 #include <linux/slab.h>
12 #include <linux/io.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/clk/ti.h>
16 #include <linux/list.h>
17
18 #include "clock.h"
19
20 #undef pr_fmt
21 #define pr_fmt(fmt) "%s: " fmt, __func__
22
ti_composite_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)23 static unsigned long ti_composite_recalc_rate(struct clk_hw *hw,
24 unsigned long parent_rate)
25 {
26 return ti_clk_divider_ops.recalc_rate(hw, parent_rate);
27 }
28
ti_composite_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)29 static long ti_composite_round_rate(struct clk_hw *hw, unsigned long rate,
30 unsigned long *prate)
31 {
32 return -EINVAL;
33 }
34
ti_composite_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)35 static int ti_composite_set_rate(struct clk_hw *hw, unsigned long rate,
36 unsigned long parent_rate)
37 {
38 return -EINVAL;
39 }
40
41 static const struct clk_ops ti_composite_divider_ops = {
42 .recalc_rate = &ti_composite_recalc_rate,
43 .round_rate = &ti_composite_round_rate,
44 .set_rate = &ti_composite_set_rate,
45 };
46
47 static const struct clk_ops ti_composite_gate_ops = {
48 .enable = &omap2_dflt_clk_enable,
49 .disable = &omap2_dflt_clk_disable,
50 .is_enabled = &omap2_dflt_clk_is_enabled,
51 };
52
53 struct component_clk {
54 int num_parents;
55 const char **parent_names;
56 struct device_node *node;
57 int type;
58 struct clk_hw *hw;
59 struct list_head link;
60 };
61
62 static const char * const component_clk_types[] __initconst = {
63 "gate", "divider", "mux"
64 };
65
66 static LIST_HEAD(component_clks);
67
_get_component_node(struct device_node * node,int i)68 static struct device_node *_get_component_node(struct device_node *node, int i)
69 {
70 int rc;
71 struct of_phandle_args clkspec;
72
73 rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
74 &clkspec);
75 if (rc)
76 return NULL;
77
78 return clkspec.np;
79 }
80
_lookup_component(struct device_node * node)81 static struct component_clk *_lookup_component(struct device_node *node)
82 {
83 struct component_clk *comp;
84
85 list_for_each_entry(comp, &component_clks, link) {
86 if (comp->node == node)
87 return comp;
88 }
89 return NULL;
90 }
91
92 struct clk_hw_omap_comp {
93 struct clk_hw hw;
94 struct device_node *comp_nodes[CLK_COMPONENT_TYPE_MAX];
95 struct component_clk *comp_clks[CLK_COMPONENT_TYPE_MAX];
96 };
97
_get_hw(struct clk_hw_omap_comp * clk,int idx)98 static inline struct clk_hw *_get_hw(struct clk_hw_omap_comp *clk, int idx)
99 {
100 if (!clk)
101 return NULL;
102
103 if (!clk->comp_clks[idx])
104 return NULL;
105
106 return clk->comp_clks[idx]->hw;
107 }
108
109 #define to_clk_hw_comp(_hw) container_of(_hw, struct clk_hw_omap_comp, hw)
110
_register_composite(void * user,struct device_node * node)111 static void __init _register_composite(void *user,
112 struct device_node *node)
113 {
114 struct clk_hw *hw = user;
115 struct clk *clk;
116 struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
117 struct component_clk *comp;
118 int num_parents = 0;
119 const char **parent_names = NULL;
120 const char *name;
121 int i;
122 int ret;
123
124 /* Check for presence of each component clock */
125 for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
126 if (!cclk->comp_nodes[i])
127 continue;
128
129 comp = _lookup_component(cclk->comp_nodes[i]);
130 if (!comp) {
131 pr_debug("component %s not ready for %pOFn, retry\n",
132 cclk->comp_nodes[i]->name, node);
133 if (!ti_clk_retry_init(node, hw,
134 _register_composite))
135 return;
136
137 goto cleanup;
138 }
139 if (cclk->comp_clks[comp->type] != NULL) {
140 pr_err("duplicate component types for %pOFn (%s)!\n",
141 node, component_clk_types[comp->type]);
142 goto cleanup;
143 }
144
145 cclk->comp_clks[comp->type] = comp;
146
147 /* Mark this node as found */
148 cclk->comp_nodes[i] = NULL;
149 }
150
151 /* All components exists, proceed with registration */
152 for (i = CLK_COMPONENT_TYPE_MAX - 1; i >= 0; i--) {
153 comp = cclk->comp_clks[i];
154 if (!comp)
155 continue;
156 if (comp->num_parents) {
157 num_parents = comp->num_parents;
158 parent_names = comp->parent_names;
159 break;
160 }
161 }
162
163 if (!num_parents) {
164 pr_err("%s: no parents found for %pOFn!\n", __func__, node);
165 goto cleanup;
166 }
167
168 name = ti_dt_clk_name(node);
169 clk = clk_register_composite(NULL, name,
170 parent_names, num_parents,
171 _get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
172 &ti_clk_mux_ops,
173 _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
174 &ti_composite_divider_ops,
175 _get_hw(cclk, CLK_COMPONENT_TYPE_GATE),
176 &ti_composite_gate_ops, 0);
177
178 if (!IS_ERR(clk)) {
179 ret = ti_clk_add_alias(NULL, clk, name);
180 if (ret) {
181 clk_unregister(clk);
182 goto cleanup;
183 }
184 of_clk_add_provider(node, of_clk_src_simple_get, clk);
185 }
186
187 cleanup:
188 /* Free component clock list entries */
189 for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
190 if (!cclk->comp_clks[i])
191 continue;
192 list_del(&cclk->comp_clks[i]->link);
193 kfree(cclk->comp_clks[i]->parent_names);
194 kfree(cclk->comp_clks[i]);
195 }
196
197 kfree(cclk);
198 }
199
of_ti_composite_clk_setup(struct device_node * node)200 static void __init of_ti_composite_clk_setup(struct device_node *node)
201 {
202 unsigned int num_clks;
203 int i;
204 struct clk_hw_omap_comp *cclk;
205
206 /* Number of component clocks to be put inside this clock */
207 num_clks = of_clk_get_parent_count(node);
208
209 if (!num_clks) {
210 pr_err("composite clk %pOFn must have component(s)\n", node);
211 return;
212 }
213
214 cclk = kzalloc(sizeof(*cclk), GFP_KERNEL);
215 if (!cclk)
216 return;
217
218 /* Get device node pointers for each component clock */
219 for (i = 0; i < num_clks; i++)
220 cclk->comp_nodes[i] = _get_component_node(node, i);
221
222 _register_composite(&cclk->hw, node);
223 }
224 CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
225 of_ti_composite_clk_setup);
226
227 /**
228 * ti_clk_add_component - add a component clock to the pool
229 * @node: device node of the component clock
230 * @hw: hardware clock definition for the component clock
231 * @type: type of the component clock
232 *
233 * Adds a component clock to the list of available components, so that
234 * it can be registered by a composite clock.
235 */
ti_clk_add_component(struct device_node * node,struct clk_hw * hw,int type)236 int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
237 int type)
238 {
239 unsigned int num_parents;
240 const char **parent_names;
241 struct component_clk *clk;
242
243 num_parents = of_clk_get_parent_count(node);
244
245 if (!num_parents) {
246 pr_err("component-clock %pOFn must have parent(s)\n", node);
247 return -EINVAL;
248 }
249
250 parent_names = kcalloc(num_parents, sizeof(char *), GFP_KERNEL);
251 if (!parent_names)
252 return -ENOMEM;
253
254 of_clk_parent_fill(node, parent_names, num_parents);
255
256 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
257 if (!clk) {
258 kfree(parent_names);
259 return -ENOMEM;
260 }
261
262 clk->num_parents = num_parents;
263 clk->parent_names = parent_names;
264 clk->hw = hw;
265 clk->node = node;
266 clk->type = type;
267 list_add(&clk->link, &component_clks);
268
269 return 0;
270 }
271