xref: /linux/drivers/clk/ti/clk.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  * TI clock support
3  *
4  * Copyright (C) 2013 Texas Instruments, Inc.
5  *
6  * Tero Kristo <t-kristo@ti.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13  * kind, whether express or implied; without even the implied warranty
14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17 
18 #include <linux/clk-provider.h>
19 #include <linux/clkdev.h>
20 #include <linux/clk/ti.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/list.h>
24 
25 #include "clock.h"
26 
27 #undef pr_fmt
28 #define pr_fmt(fmt) "%s: " fmt, __func__
29 
30 struct ti_clk_ll_ops *ti_clk_ll_ops;
31 static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS];
32 
33 /**
34  * ti_dt_clocks_register - register DT alias clocks during boot
35  * @oclks: list of clocks to register
36  *
37  * Register alias or non-standard DT clock entries during boot. By
38  * default, DT clocks are found based on their node name. If any
39  * additional con-id / dev-id -> clock mapping is required, use this
40  * function to list these.
41  */
42 void __init ti_dt_clocks_register(struct ti_dt_clk oclks[])
43 {
44 	struct ti_dt_clk *c;
45 	struct device_node *node;
46 	struct clk *clk;
47 	struct of_phandle_args clkspec;
48 
49 	for (c = oclks; c->node_name != NULL; c++) {
50 		node = of_find_node_by_name(NULL, c->node_name);
51 		clkspec.np = node;
52 		clk = of_clk_get_from_provider(&clkspec);
53 
54 		if (!IS_ERR(clk)) {
55 			c->lk.clk = clk;
56 			clkdev_add(&c->lk);
57 		} else {
58 			pr_warn("failed to lookup clock node %s\n",
59 				c->node_name);
60 		}
61 	}
62 }
63 
64 struct clk_init_item {
65 	struct device_node *node;
66 	struct clk_hw *hw;
67 	ti_of_clk_init_cb_t func;
68 	struct list_head link;
69 };
70 
71 static LIST_HEAD(retry_list);
72 
73 /**
74  * ti_clk_retry_init - retries a failed clock init at later phase
75  * @node: device not for the clock
76  * @hw: partially initialized clk_hw struct for the clock
77  * @func: init function to be called for the clock
78  *
79  * Adds a failed clock init to the retry list. The retry list is parsed
80  * once all the other clocks have been initialized.
81  */
82 int __init ti_clk_retry_init(struct device_node *node, struct clk_hw *hw,
83 			      ti_of_clk_init_cb_t func)
84 {
85 	struct clk_init_item *retry;
86 
87 	pr_debug("%s: adding to retry list...\n", node->name);
88 	retry = kzalloc(sizeof(*retry), GFP_KERNEL);
89 	if (!retry)
90 		return -ENOMEM;
91 
92 	retry->node = node;
93 	retry->func = func;
94 	retry->hw = hw;
95 	list_add(&retry->link, &retry_list);
96 
97 	return 0;
98 }
99 
100 /**
101  * ti_clk_get_reg_addr - get register address for a clock register
102  * @node: device node for the clock
103  * @index: register index from the clock node
104  *
105  * Builds clock register address from device tree information. This
106  * is a struct of type clk_omap_reg.
107  */
108 void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
109 {
110 	struct clk_omap_reg *reg;
111 	u32 val;
112 	u32 tmp;
113 	int i;
114 
115 	reg = (struct clk_omap_reg *)&tmp;
116 
117 	for (i = 0; i < CLK_MAX_MEMMAPS; i++) {
118 		if (clocks_node_ptr[i] == node->parent)
119 			break;
120 	}
121 
122 	if (i == CLK_MAX_MEMMAPS) {
123 		pr_err("clk-provider not found for %s!\n", node->name);
124 		return NULL;
125 	}
126 
127 	reg->index = i;
128 
129 	if (of_property_read_u32_index(node, "reg", index, &val)) {
130 		pr_err("%s must have reg[%d]!\n", node->name, index);
131 		return NULL;
132 	}
133 
134 	reg->offset = val;
135 
136 	return (void __iomem *)tmp;
137 }
138 
139 /**
140  * ti_dt_clk_init_provider - init master clock provider
141  * @parent: master node
142  * @index: internal index for clk_reg_ops
143  *
144  * Initializes a master clock IP block. This basically sets up the
145  * mapping from clocks node to the memory map index. All the clocks
146  * are then initialized through the common of_clk_init call, and the
147  * clocks will access their memory maps based on the node layout.
148  */
149 void ti_dt_clk_init_provider(struct device_node *parent, int index)
150 {
151 	struct device_node *clocks;
152 
153 	/* get clocks for this parent */
154 	clocks = of_get_child_by_name(parent, "clocks");
155 	if (!clocks) {
156 		pr_err("%s missing 'clocks' child node.\n", parent->name);
157 		return;
158 	}
159 
160 	/* add clocks node info */
161 	clocks_node_ptr[index] = clocks;
162 }
163 
164 /**
165  * ti_dt_clk_init_retry_clks - init clocks from the retry list
166  *
167  * Initializes any clocks that have failed to initialize before,
168  * reasons being missing parent node(s) during earlier init. This
169  * typically happens only for DPLLs which need to have both of their
170  * parent clocks ready during init.
171  */
172 void ti_dt_clk_init_retry_clks(void)
173 {
174 	struct clk_init_item *retry;
175 	struct clk_init_item *tmp;
176 	int retries = 5;
177 
178 	while (!list_empty(&retry_list) && retries) {
179 		list_for_each_entry_safe(retry, tmp, &retry_list, link) {
180 			pr_debug("retry-init: %s\n", retry->node->name);
181 			retry->func(retry->hw, retry->node);
182 			list_del(&retry->link);
183 			kfree(retry);
184 		}
185 		retries--;
186 	}
187 }
188 
189 #if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_ATAGS)
190 void __init ti_clk_patch_legacy_clks(struct ti_clk **patch)
191 {
192 	while (*patch) {
193 		memcpy((*patch)->patch, *patch, sizeof(**patch));
194 		patch++;
195 	}
196 }
197 
198 struct clk __init *ti_clk_register_clk(struct ti_clk *setup)
199 {
200 	struct clk *clk;
201 	struct ti_clk_fixed *fixed;
202 	struct ti_clk_fixed_factor *fixed_factor;
203 	struct clk_hw *clk_hw;
204 
205 	if (setup->clk)
206 		return setup->clk;
207 
208 	switch (setup->type) {
209 	case TI_CLK_FIXED:
210 		fixed = setup->data;
211 
212 		clk = clk_register_fixed_rate(NULL, setup->name, NULL,
213 					      CLK_IS_ROOT, fixed->frequency);
214 		break;
215 	case TI_CLK_MUX:
216 		clk = ti_clk_register_mux(setup);
217 		break;
218 	case TI_CLK_DIVIDER:
219 		clk = ti_clk_register_divider(setup);
220 		break;
221 	case TI_CLK_COMPOSITE:
222 		clk = ti_clk_register_composite(setup);
223 		break;
224 	case TI_CLK_FIXED_FACTOR:
225 		fixed_factor = setup->data;
226 
227 		clk = clk_register_fixed_factor(NULL, setup->name,
228 						fixed_factor->parent,
229 						0, fixed_factor->mult,
230 						fixed_factor->div);
231 		break;
232 	case TI_CLK_GATE:
233 		clk = ti_clk_register_gate(setup);
234 		break;
235 	case TI_CLK_DPLL:
236 		clk = ti_clk_register_dpll(setup);
237 		break;
238 	default:
239 		pr_err("bad type for %s!\n", setup->name);
240 		clk = ERR_PTR(-EINVAL);
241 	}
242 
243 	if (!IS_ERR(clk)) {
244 		setup->clk = clk;
245 		if (setup->clkdm_name) {
246 			if (__clk_get_flags(clk) & CLK_IS_BASIC) {
247 				pr_warn("can't setup clkdm for basic clk %s\n",
248 					setup->name);
249 			} else {
250 				clk_hw = __clk_get_hw(clk);
251 				to_clk_hw_omap(clk_hw)->clkdm_name =
252 					setup->clkdm_name;
253 				omap2_init_clk_clkdm(clk_hw);
254 			}
255 		}
256 	}
257 
258 	return clk;
259 }
260 
261 int __init ti_clk_register_legacy_clks(struct ti_clk_alias *clks)
262 {
263 	struct clk *clk;
264 	bool retry;
265 	struct ti_clk_alias *retry_clk;
266 	struct ti_clk_alias *tmp;
267 
268 	while (clks->clk) {
269 		clk = ti_clk_register_clk(clks->clk);
270 		if (IS_ERR(clk)) {
271 			if (PTR_ERR(clk) == -EAGAIN) {
272 				list_add(&clks->link, &retry_list);
273 			} else {
274 				pr_err("register for %s failed: %ld\n",
275 				       clks->clk->name, PTR_ERR(clk));
276 				return PTR_ERR(clk);
277 			}
278 		} else {
279 			clks->lk.clk = clk;
280 			clkdev_add(&clks->lk);
281 		}
282 		clks++;
283 	}
284 
285 	retry = true;
286 
287 	while (!list_empty(&retry_list) && retry) {
288 		retry = false;
289 		list_for_each_entry_safe(retry_clk, tmp, &retry_list, link) {
290 			pr_debug("retry-init: %s\n", retry_clk->clk->name);
291 			clk = ti_clk_register_clk(retry_clk->clk);
292 			if (IS_ERR(clk)) {
293 				if (PTR_ERR(clk) == -EAGAIN) {
294 					continue;
295 				} else {
296 					pr_err("register for %s failed: %ld\n",
297 					       retry_clk->clk->name,
298 					       PTR_ERR(clk));
299 					return PTR_ERR(clk);
300 				}
301 			} else {
302 				retry = true;
303 				retry_clk->lk.clk = clk;
304 				clkdev_add(&retry_clk->lk);
305 				list_del(&retry_clk->link);
306 			}
307 		}
308 	}
309 
310 	return 0;
311 }
312 #endif
313