xref: /openbmc/linux/drivers/clk/ti/apll.c (revision 0a907292) 
1 /*
2  * OMAP APLL clock support
3  *
4  * Copyright (C) 2013 Texas Instruments, Inc.
5  *
6  * J Keerthy <j-keerthy@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.h>
19 #include <linux/clk-provider.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/io.h>
23 #include <linux/err.h>
24 #include <linux/string.h>
25 #include <linux/log2.h>
26 #include <linux/of.h>
27 #include <linux/of_address.h>
28 #include <linux/clk/ti.h>
29 #include <linux/delay.h>
30 
31 #include "clock.h"
32 
33 #define APLL_FORCE_LOCK 0x1
34 #define APLL_AUTO_IDLE	0x2
35 #define MAX_APLL_WAIT_TRIES		1000000
36 
37 #undef pr_fmt
38 #define pr_fmt(fmt) "%s: " fmt, __func__
39 
40 static int dra7_apll_enable(struct clk_hw *hw)
41 {
42 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
43 	int r = 0, i = 0;
44 	struct dpll_data *ad;
45 	const char *clk_name;
46 	u8 state = 1;
47 	u32 v;
48 
49 	ad = clk->dpll_data;
50 	if (!ad)
51 		return -EINVAL;
52 
53 	clk_name = clk_hw_get_name(&clk->hw);
54 
55 	state <<= __ffs(ad->idlest_mask);
56 
57 	/* Check is already locked */
58 	v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
59 
60 	if ((v & ad->idlest_mask) == state)
61 		return r;
62 
63 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
64 	v &= ~ad->enable_mask;
65 	v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask);
66 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
67 
68 	state <<= __ffs(ad->idlest_mask);
69 
70 	while (1) {
71 		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
72 		if ((v & ad->idlest_mask) == state)
73 			break;
74 		if (i > MAX_APLL_WAIT_TRIES)
75 			break;
76 		i++;
77 		udelay(1);
78 	}
79 
80 	if (i == MAX_APLL_WAIT_TRIES) {
81 		pr_warn("clock: %s failed transition to '%s'\n",
82 			clk_name, (state) ? "locked" : "bypassed");
83 		r = -EBUSY;
84 	} else
85 		pr_debug("clock: %s transition to '%s' in %d loops\n",
86 			 clk_name, (state) ? "locked" : "bypassed", i);
87 
88 	return r;
89 }
90 
91 static void dra7_apll_disable(struct clk_hw *hw)
92 {
93 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
94 	struct dpll_data *ad;
95 	u8 state = 1;
96 	u32 v;
97 
98 	ad = clk->dpll_data;
99 
100 	state <<= __ffs(ad->idlest_mask);
101 
102 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
103 	v &= ~ad->enable_mask;
104 	v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask);
105 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
106 }
107 
108 static int dra7_apll_is_enabled(struct clk_hw *hw)
109 {
110 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
111 	struct dpll_data *ad;
112 	u32 v;
113 
114 	ad = clk->dpll_data;
115 
116 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
117 	v &= ad->enable_mask;
118 
119 	v >>= __ffs(ad->enable_mask);
120 
121 	return v == APLL_AUTO_IDLE ? 0 : 1;
122 }
123 
124 static u8 dra7_init_apll_parent(struct clk_hw *hw)
125 {
126 	return 0;
127 }
128 
129 static const struct clk_ops apll_ck_ops = {
130 	.enable		= &dra7_apll_enable,
131 	.disable	= &dra7_apll_disable,
132 	.is_enabled	= &dra7_apll_is_enabled,
133 	.get_parent	= &dra7_init_apll_parent,
134 };
135 
136 static void __init omap_clk_register_apll(void *user,
137 					  struct device_node *node)
138 {
139 	struct clk_hw *hw = user;
140 	struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw);
141 	struct dpll_data *ad = clk_hw->dpll_data;
142 	struct clk *clk;
143 	const struct clk_init_data *init = clk_hw->hw.init;
144 
145 	clk = of_clk_get(node, 0);
146 	if (IS_ERR(clk)) {
147 		pr_debug("clk-ref for %pOFn not ready, retry\n",
148 			 node);
149 		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
150 			return;
151 
152 		goto cleanup;
153 	}
154 
155 	ad->clk_ref = __clk_get_hw(clk);
156 
157 	clk = of_clk_get(node, 1);
158 	if (IS_ERR(clk)) {
159 		pr_debug("clk-bypass for %pOFn not ready, retry\n",
160 			 node);
161 		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
162 			return;
163 
164 		goto cleanup;
165 	}
166 
167 	ad->clk_bypass = __clk_get_hw(clk);
168 
169 	clk = ti_clk_register_omap_hw(NULL, &clk_hw->hw, node->name);
170 	if (!IS_ERR(clk)) {
171 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
172 		kfree(init->parent_names);
173 		kfree(init);
174 		return;
175 	}
176 
177 cleanup:
178 	kfree(clk_hw->dpll_data);
179 	kfree(init->parent_names);
180 	kfree(init);
181 	kfree(clk_hw);
182 }
183 
184 static void __init of_dra7_apll_setup(struct device_node *node)
185 {
186 	struct dpll_data *ad = NULL;
187 	struct clk_hw_omap *clk_hw = NULL;
188 	struct clk_init_data *init = NULL;
189 	const char **parent_names = NULL;
190 	int ret;
191 
192 	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
193 	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
194 	init = kzalloc(sizeof(*init), GFP_KERNEL);
195 	if (!ad || !clk_hw || !init)
196 		goto cleanup;
197 
198 	clk_hw->dpll_data = ad;
199 	clk_hw->hw.init = init;
200 
201 	init->name = node->name;
202 	init->ops = &apll_ck_ops;
203 
204 	init->num_parents = of_clk_get_parent_count(node);
205 	if (init->num_parents < 1) {
206 		pr_err("dra7 apll %pOFn must have parent(s)\n", node);
207 		goto cleanup;
208 	}
209 
210 	parent_names = kcalloc(init->num_parents, sizeof(char *), GFP_KERNEL);
211 	if (!parent_names)
212 		goto cleanup;
213 
214 	of_clk_parent_fill(node, parent_names, init->num_parents);
215 
216 	init->parent_names = parent_names;
217 
218 	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
219 	ret |= ti_clk_get_reg_addr(node, 1, &ad->idlest_reg);
220 
221 	if (ret)
222 		goto cleanup;
223 
224 	ad->idlest_mask = 0x1;
225 	ad->enable_mask = 0x3;
226 
227 	omap_clk_register_apll(&clk_hw->hw, node);
228 	return;
229 
230 cleanup:
231 	kfree(parent_names);
232 	kfree(ad);
233 	kfree(clk_hw);
234 	kfree(init);
235 }
236 CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);
237 
238 #define OMAP2_EN_APLL_LOCKED	0x3
239 #define OMAP2_EN_APLL_STOPPED	0x0
240 
241 static int omap2_apll_is_enabled(struct clk_hw *hw)
242 {
243 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
244 	struct dpll_data *ad = clk->dpll_data;
245 	u32 v;
246 
247 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
248 	v &= ad->enable_mask;
249 
250 	v >>= __ffs(ad->enable_mask);
251 
252 	return v == OMAP2_EN_APLL_LOCKED ? 1 : 0;
253 }
254 
255 static unsigned long omap2_apll_recalc(struct clk_hw *hw,
256 				       unsigned long parent_rate)
257 {
258 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
259 
260 	if (omap2_apll_is_enabled(hw))
261 		return clk->fixed_rate;
262 
263 	return 0;
264 }
265 
266 static int omap2_apll_enable(struct clk_hw *hw)
267 {
268 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
269 	struct dpll_data *ad = clk->dpll_data;
270 	u32 v;
271 	int i = 0;
272 
273 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
274 	v &= ~ad->enable_mask;
275 	v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask);
276 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
277 
278 	while (1) {
279 		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
280 		if (v & ad->idlest_mask)
281 			break;
282 		if (i > MAX_APLL_WAIT_TRIES)
283 			break;
284 		i++;
285 		udelay(1);
286 	}
287 
288 	if (i == MAX_APLL_WAIT_TRIES) {
289 		pr_warn("%s failed to transition to locked\n",
290 			clk_hw_get_name(&clk->hw));
291 		return -EBUSY;
292 	}
293 
294 	return 0;
295 }
296 
297 static void omap2_apll_disable(struct clk_hw *hw)
298 {
299 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
300 	struct dpll_data *ad = clk->dpll_data;
301 	u32 v;
302 
303 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
304 	v &= ~ad->enable_mask;
305 	v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask);
306 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
307 }
308 
309 static const struct clk_ops omap2_apll_ops = {
310 	.enable		= &omap2_apll_enable,
311 	.disable	= &omap2_apll_disable,
312 	.is_enabled	= &omap2_apll_is_enabled,
313 	.recalc_rate	= &omap2_apll_recalc,
314 };
315 
316 static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val)
317 {
318 	struct dpll_data *ad = clk->dpll_data;
319 	u32 v;
320 
321 	v = ti_clk_ll_ops->clk_readl(&ad->autoidle_reg);
322 	v &= ~ad->autoidle_mask;
323 	v |= val << __ffs(ad->autoidle_mask);
324 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
325 }
326 
327 #define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP	0x3
328 #define OMAP2_APLL_AUTOIDLE_DISABLE		0x0
329 
330 static void omap2_apll_allow_idle(struct clk_hw_omap *clk)
331 {
332 	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP);
333 }
334 
335 static void omap2_apll_deny_idle(struct clk_hw_omap *clk)
336 {
337 	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE);
338 }
339 
340 static const struct clk_hw_omap_ops omap2_apll_hwops = {
341 	.allow_idle	= &omap2_apll_allow_idle,
342 	.deny_idle	= &omap2_apll_deny_idle,
343 };
344 
345 static void __init of_omap2_apll_setup(struct device_node *node)
346 {
347 	struct dpll_data *ad = NULL;
348 	struct clk_hw_omap *clk_hw = NULL;
349 	struct clk_init_data *init = NULL;
350 	struct clk *clk;
351 	const char *parent_name;
352 	u32 val;
353 	int ret;
354 
355 	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
356 	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
357 	init = kzalloc(sizeof(*init), GFP_KERNEL);
358 
359 	if (!ad || !clk_hw || !init)
360 		goto cleanup;
361 
362 	clk_hw->dpll_data = ad;
363 	clk_hw->hw.init = init;
364 	init->ops = &omap2_apll_ops;
365 	init->name = node->name;
366 	clk_hw->ops = &omap2_apll_hwops;
367 
368 	init->num_parents = of_clk_get_parent_count(node);
369 	if (init->num_parents != 1) {
370 		pr_err("%pOFn must have one parent\n", node);
371 		goto cleanup;
372 	}
373 
374 	parent_name = of_clk_get_parent_name(node, 0);
375 	init->parent_names = &parent_name;
376 
377 	if (of_property_read_u32(node, "ti,clock-frequency", &val)) {
378 		pr_err("%pOFn missing clock-frequency\n", node);
379 		goto cleanup;
380 	}
381 	clk_hw->fixed_rate = val;
382 
383 	if (of_property_read_u32(node, "ti,bit-shift", &val)) {
384 		pr_err("%pOFn missing bit-shift\n", node);
385 		goto cleanup;
386 	}
387 
388 	clk_hw->enable_bit = val;
389 	ad->enable_mask = 0x3 << val;
390 	ad->autoidle_mask = 0x3 << val;
391 
392 	if (of_property_read_u32(node, "ti,idlest-shift", &val)) {
393 		pr_err("%pOFn missing idlest-shift\n", node);
394 		goto cleanup;
395 	}
396 
397 	ad->idlest_mask = 1 << val;
398 
399 	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
400 	ret |= ti_clk_get_reg_addr(node, 1, &ad->autoidle_reg);
401 	ret |= ti_clk_get_reg_addr(node, 2, &ad->idlest_reg);
402 
403 	if (ret)
404 		goto cleanup;
405 
406 	clk = ti_clk_register_omap_hw(NULL, &clk_hw->hw, node->name);
407 	if (!IS_ERR(clk)) {
408 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
409 		kfree(init);
410 		return;
411 	}
412 cleanup:
413 	kfree(ad);
414 	kfree(clk_hw);
415 	kfree(init);
416 }
417 CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock",
418 	       of_omap2_apll_setup);
419