xref: /openbmc/linux/drivers/clk/ti/apll.c (revision 7cc39531) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP APLL clock support
4  *
5  * Copyright (C) 2013 Texas Instruments, Inc.
6  *
7  * J Keerthy <j-keerthy@ti.com>
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/io.h>
15 #include <linux/err.h>
16 #include <linux/string.h>
17 #include <linux/log2.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/clk/ti.h>
21 #include <linux/delay.h>
22 
23 #include "clock.h"
24 
25 #define APLL_FORCE_LOCK 0x1
26 #define APLL_AUTO_IDLE	0x2
27 #define MAX_APLL_WAIT_TRIES		1000000
28 
29 #undef pr_fmt
30 #define pr_fmt(fmt) "%s: " fmt, __func__
31 
32 static int dra7_apll_enable(struct clk_hw *hw)
33 {
34 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
35 	int r = 0, i = 0;
36 	struct dpll_data *ad;
37 	const char *clk_name;
38 	u8 state = 1;
39 	u32 v;
40 
41 	ad = clk->dpll_data;
42 	if (!ad)
43 		return -EINVAL;
44 
45 	clk_name = clk_hw_get_name(&clk->hw);
46 
47 	state <<= __ffs(ad->idlest_mask);
48 
49 	/* Check is already locked */
50 	v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
51 
52 	if ((v & ad->idlest_mask) == state)
53 		return r;
54 
55 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
56 	v &= ~ad->enable_mask;
57 	v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask);
58 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
59 
60 	state <<= __ffs(ad->idlest_mask);
61 
62 	while (1) {
63 		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
64 		if ((v & ad->idlest_mask) == state)
65 			break;
66 		if (i > MAX_APLL_WAIT_TRIES)
67 			break;
68 		i++;
69 		udelay(1);
70 	}
71 
72 	if (i == MAX_APLL_WAIT_TRIES) {
73 		pr_warn("clock: %s failed transition to '%s'\n",
74 			clk_name, (state) ? "locked" : "bypassed");
75 		r = -EBUSY;
76 	} else
77 		pr_debug("clock: %s transition to '%s' in %d loops\n",
78 			 clk_name, (state) ? "locked" : "bypassed", i);
79 
80 	return r;
81 }
82 
83 static void dra7_apll_disable(struct clk_hw *hw)
84 {
85 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
86 	struct dpll_data *ad;
87 	u8 state = 1;
88 	u32 v;
89 
90 	ad = clk->dpll_data;
91 
92 	state <<= __ffs(ad->idlest_mask);
93 
94 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
95 	v &= ~ad->enable_mask;
96 	v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask);
97 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
98 }
99 
100 static int dra7_apll_is_enabled(struct clk_hw *hw)
101 {
102 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
103 	struct dpll_data *ad;
104 	u32 v;
105 
106 	ad = clk->dpll_data;
107 
108 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
109 	v &= ad->enable_mask;
110 
111 	v >>= __ffs(ad->enable_mask);
112 
113 	return v == APLL_AUTO_IDLE ? 0 : 1;
114 }
115 
116 static u8 dra7_init_apll_parent(struct clk_hw *hw)
117 {
118 	return 0;
119 }
120 
121 static const struct clk_ops apll_ck_ops = {
122 	.enable		= &dra7_apll_enable,
123 	.disable	= &dra7_apll_disable,
124 	.is_enabled	= &dra7_apll_is_enabled,
125 	.get_parent	= &dra7_init_apll_parent,
126 };
127 
128 static void __init omap_clk_register_apll(void *user,
129 					  struct device_node *node)
130 {
131 	struct clk_hw *hw = user;
132 	struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw);
133 	struct dpll_data *ad = clk_hw->dpll_data;
134 	const char *name;
135 	struct clk *clk;
136 	const struct clk_init_data *init = clk_hw->hw.init;
137 
138 	clk = of_clk_get(node, 0);
139 	if (IS_ERR(clk)) {
140 		pr_debug("clk-ref for %pOFn not ready, retry\n",
141 			 node);
142 		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
143 			return;
144 
145 		goto cleanup;
146 	}
147 
148 	ad->clk_ref = __clk_get_hw(clk);
149 
150 	clk = of_clk_get(node, 1);
151 	if (IS_ERR(clk)) {
152 		pr_debug("clk-bypass for %pOFn not ready, retry\n",
153 			 node);
154 		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
155 			return;
156 
157 		goto cleanup;
158 	}
159 
160 	ad->clk_bypass = __clk_get_hw(clk);
161 
162 	name = ti_dt_clk_name(node);
163 	clk = ti_clk_register_omap_hw(NULL, &clk_hw->hw, name);
164 	if (!IS_ERR(clk)) {
165 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
166 		kfree(init->parent_names);
167 		kfree(init);
168 		return;
169 	}
170 
171 cleanup:
172 	kfree(clk_hw->dpll_data);
173 	kfree(init->parent_names);
174 	kfree(init);
175 	kfree(clk_hw);
176 }
177 
178 static void __init of_dra7_apll_setup(struct device_node *node)
179 {
180 	struct dpll_data *ad = NULL;
181 	struct clk_hw_omap *clk_hw = NULL;
182 	struct clk_init_data *init = NULL;
183 	const char **parent_names = NULL;
184 	int ret;
185 
186 	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
187 	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
188 	init = kzalloc(sizeof(*init), GFP_KERNEL);
189 	if (!ad || !clk_hw || !init)
190 		goto cleanup;
191 
192 	clk_hw->dpll_data = ad;
193 	clk_hw->hw.init = init;
194 
195 	init->name = ti_dt_clk_name(node);
196 	init->ops = &apll_ck_ops;
197 
198 	init->num_parents = of_clk_get_parent_count(node);
199 	if (init->num_parents < 1) {
200 		pr_err("dra7 apll %pOFn must have parent(s)\n", node);
201 		goto cleanup;
202 	}
203 
204 	parent_names = kcalloc(init->num_parents, sizeof(char *), GFP_KERNEL);
205 	if (!parent_names)
206 		goto cleanup;
207 
208 	of_clk_parent_fill(node, parent_names, init->num_parents);
209 
210 	init->parent_names = parent_names;
211 
212 	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
213 	ret |= ti_clk_get_reg_addr(node, 1, &ad->idlest_reg);
214 
215 	if (ret)
216 		goto cleanup;
217 
218 	ad->idlest_mask = 0x1;
219 	ad->enable_mask = 0x3;
220 
221 	omap_clk_register_apll(&clk_hw->hw, node);
222 	return;
223 
224 cleanup:
225 	kfree(parent_names);
226 	kfree(ad);
227 	kfree(clk_hw);
228 	kfree(init);
229 }
230 CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);
231 
232 #define OMAP2_EN_APLL_LOCKED	0x3
233 #define OMAP2_EN_APLL_STOPPED	0x0
234 
235 static int omap2_apll_is_enabled(struct clk_hw *hw)
236 {
237 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
238 	struct dpll_data *ad = clk->dpll_data;
239 	u32 v;
240 
241 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
242 	v &= ad->enable_mask;
243 
244 	v >>= __ffs(ad->enable_mask);
245 
246 	return v == OMAP2_EN_APLL_LOCKED ? 1 : 0;
247 }
248 
249 static unsigned long omap2_apll_recalc(struct clk_hw *hw,
250 				       unsigned long parent_rate)
251 {
252 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
253 
254 	if (omap2_apll_is_enabled(hw))
255 		return clk->fixed_rate;
256 
257 	return 0;
258 }
259 
260 static int omap2_apll_enable(struct clk_hw *hw)
261 {
262 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
263 	struct dpll_data *ad = clk->dpll_data;
264 	u32 v;
265 	int i = 0;
266 
267 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
268 	v &= ~ad->enable_mask;
269 	v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask);
270 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
271 
272 	while (1) {
273 		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
274 		if (v & ad->idlest_mask)
275 			break;
276 		if (i > MAX_APLL_WAIT_TRIES)
277 			break;
278 		i++;
279 		udelay(1);
280 	}
281 
282 	if (i == MAX_APLL_WAIT_TRIES) {
283 		pr_warn("%s failed to transition to locked\n",
284 			clk_hw_get_name(&clk->hw));
285 		return -EBUSY;
286 	}
287 
288 	return 0;
289 }
290 
291 static void omap2_apll_disable(struct clk_hw *hw)
292 {
293 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
294 	struct dpll_data *ad = clk->dpll_data;
295 	u32 v;
296 
297 	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
298 	v &= ~ad->enable_mask;
299 	v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask);
300 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
301 }
302 
303 static const struct clk_ops omap2_apll_ops = {
304 	.enable		= &omap2_apll_enable,
305 	.disable	= &omap2_apll_disable,
306 	.is_enabled	= &omap2_apll_is_enabled,
307 	.recalc_rate	= &omap2_apll_recalc,
308 };
309 
310 static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val)
311 {
312 	struct dpll_data *ad = clk->dpll_data;
313 	u32 v;
314 
315 	v = ti_clk_ll_ops->clk_readl(&ad->autoidle_reg);
316 	v &= ~ad->autoidle_mask;
317 	v |= val << __ffs(ad->autoidle_mask);
318 	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
319 }
320 
321 #define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP	0x3
322 #define OMAP2_APLL_AUTOIDLE_DISABLE		0x0
323 
324 static void omap2_apll_allow_idle(struct clk_hw_omap *clk)
325 {
326 	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP);
327 }
328 
329 static void omap2_apll_deny_idle(struct clk_hw_omap *clk)
330 {
331 	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE);
332 }
333 
334 static const struct clk_hw_omap_ops omap2_apll_hwops = {
335 	.allow_idle	= &omap2_apll_allow_idle,
336 	.deny_idle	= &omap2_apll_deny_idle,
337 };
338 
339 static void __init of_omap2_apll_setup(struct device_node *node)
340 {
341 	struct dpll_data *ad = NULL;
342 	struct clk_hw_omap *clk_hw = NULL;
343 	struct clk_init_data *init = NULL;
344 	const char *name;
345 	struct clk *clk;
346 	const char *parent_name;
347 	u32 val;
348 	int ret;
349 
350 	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
351 	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
352 	init = kzalloc(sizeof(*init), GFP_KERNEL);
353 
354 	if (!ad || !clk_hw || !init)
355 		goto cleanup;
356 
357 	clk_hw->dpll_data = ad;
358 	clk_hw->hw.init = init;
359 	init->ops = &omap2_apll_ops;
360 	name = ti_dt_clk_name(node);
361 	init->name = name;
362 	clk_hw->ops = &omap2_apll_hwops;
363 
364 	init->num_parents = of_clk_get_parent_count(node);
365 	if (init->num_parents != 1) {
366 		pr_err("%pOFn must have one parent\n", node);
367 		goto cleanup;
368 	}
369 
370 	parent_name = of_clk_get_parent_name(node, 0);
371 	init->parent_names = &parent_name;
372 
373 	if (of_property_read_u32(node, "ti,clock-frequency", &val)) {
374 		pr_err("%pOFn missing clock-frequency\n", node);
375 		goto cleanup;
376 	}
377 	clk_hw->fixed_rate = val;
378 
379 	if (of_property_read_u32(node, "ti,bit-shift", &val)) {
380 		pr_err("%pOFn missing bit-shift\n", node);
381 		goto cleanup;
382 	}
383 
384 	clk_hw->enable_bit = val;
385 	ad->enable_mask = 0x3 << val;
386 	ad->autoidle_mask = 0x3 << val;
387 
388 	if (of_property_read_u32(node, "ti,idlest-shift", &val)) {
389 		pr_err("%pOFn missing idlest-shift\n", node);
390 		goto cleanup;
391 	}
392 
393 	ad->idlest_mask = 1 << val;
394 
395 	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
396 	ret |= ti_clk_get_reg_addr(node, 1, &ad->autoidle_reg);
397 	ret |= ti_clk_get_reg_addr(node, 2, &ad->idlest_reg);
398 
399 	if (ret)
400 		goto cleanup;
401 
402 	name = ti_dt_clk_name(node);
403 	clk = ti_clk_register_omap_hw(NULL, &clk_hw->hw, name);
404 	if (!IS_ERR(clk)) {
405 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
406 		kfree(init);
407 		return;
408 	}
409 cleanup:
410 	kfree(ad);
411 	kfree(clk_hw);
412 	kfree(init);
413 }
414 CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock",
415 	       of_omap2_apll_setup);
416