xref: /linux/drivers/clk/qcom/clk-cpu-8996.c (revision 9daaaaaa)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2020, The Linux Foundation. All rights reserved.
4  */
5 
6 /*
7  * Each of the CPU clusters (Power and Perf) on msm8996 are
8  * clocked via 2 PLLs, a primary and alternate. There are also
9  * 2 Mux'es, a primary and secondary all connected together
10  * as shown below
11  *
12  *                              +-------+
13  *               XO             |       |
14  *           +------------------>0      |
15  *               SYS_APCS_AUX   |       |
16  *           +------------------>3      |
17  *                              |       |
18  *                    PLL/2     | SMUX  +----+
19  *                      +------->1      |    |
20  *                      |       |       |    |
21  *                      |       +-------+    |    +-------+
22  *                      |                    +---->0      |
23  *                      |                         |       |
24  * +---------------+    |             +----------->1      | CPU clk
25  * |Primary PLL    +----+ PLL_EARLY   |           |       +------>
26  * |               +------+-----------+    +------>2 PMUX |
27  * +---------------+      |                |      |       |
28  *                        |   +------+     |   +-->3      |
29  *                        +--^+  ACD +-----+   |  +-------+
30  * +---------------+          +------+         |
31  * |Alt PLL        |                           |
32  * |               +---------------------------+
33  * +---------------+         PLL_EARLY
34  *
35  * The primary PLL is what drives the CPU clk, except for times
36  * when we are reprogramming the PLL itself (for rate changes) when
37  * we temporarily switch to an alternate PLL.
38  *
39  * The primary PLL operates on a single VCO range, between 600MHz
40  * and 3GHz. However the CPUs do support OPPs with frequencies
41  * between 300MHz and 600MHz. In order to support running the CPUs
42  * at those frequencies we end up having to lock the PLL at twice
43  * the rate and drive the CPU clk via the PLL/2 output and SMUX.
44  *
45  * So for frequencies above 600MHz we follow the following path
46  *  Primary PLL --> PLL_EARLY --> PMUX(1) --> CPU clk
47  * and for frequencies between 300MHz and 600MHz we follow
48  *  Primary PLL --> PLL/2 --> SMUX(1) --> PMUX(0) --> CPU clk
49  *
50  * ACD stands for Adaptive Clock Distribution and is used to
51  * detect voltage droops.
52  */
53 
54 #include <linux/bitfield.h>
55 #include <linux/clk.h>
56 #include <linux/clk-provider.h>
57 #include <linux/io.h>
58 #include <linux/module.h>
59 #include <linux/platform_device.h>
60 #include <linux/regmap.h>
61 #include <soc/qcom/kryo-l2-accessors.h>
62 
63 #include "clk-alpha-pll.h"
64 #include "clk-regmap.h"
65 #include "clk-regmap-mux.h"
66 
67 enum _pmux_input {
68 	SMUX_INDEX = 0,
69 	PLL_INDEX,
70 	ACD_INDEX,
71 	ALT_INDEX,
72 	NUM_OF_PMUX_INPUTS
73 };
74 
75 #define DIV_2_THRESHOLD		600000000
76 #define PWRCL_REG_OFFSET 0x0
77 #define PERFCL_REG_OFFSET 0x80000
78 #define MUX_OFFSET	0x40
79 #define CLK_CTL_OFFSET 0x44
80 #define CLK_CTL_AUTO_CLK_SEL BIT(8)
81 #define ALT_PLL_OFFSET	0x100
82 #define SSSCTL_OFFSET 0x160
83 #define PSCTL_OFFSET 0x164
84 
85 #define PMUX_MASK	0x3
86 #define MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK GENMASK(5, 4)
87 #define MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL \
88 	FIELD_PREP(MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK, 0x03)
89 
90 static const u8 prim_pll_regs[PLL_OFF_MAX_REGS] = {
91 	[PLL_OFF_L_VAL] = 0x04,
92 	[PLL_OFF_ALPHA_VAL] = 0x08,
93 	[PLL_OFF_USER_CTL] = 0x10,
94 	[PLL_OFF_CONFIG_CTL] = 0x18,
95 	[PLL_OFF_CONFIG_CTL_U] = 0x1c,
96 	[PLL_OFF_TEST_CTL] = 0x20,
97 	[PLL_OFF_TEST_CTL_U] = 0x24,
98 	[PLL_OFF_STATUS] = 0x28,
99 };
100 
101 static const u8 alt_pll_regs[PLL_OFF_MAX_REGS] = {
102 	[PLL_OFF_L_VAL] = 0x04,
103 	[PLL_OFF_ALPHA_VAL] = 0x08,
104 	[PLL_OFF_USER_CTL] = 0x10,
105 	[PLL_OFF_CONFIG_CTL] = 0x18,
106 	[PLL_OFF_TEST_CTL] = 0x20,
107 	[PLL_OFF_STATUS] = 0x28,
108 };
109 
110 /* PLLs */
111 
112 static const struct alpha_pll_config hfpll_config = {
113 	.l = 54,
114 	.config_ctl_val = 0x200d4828,
115 	.config_ctl_hi_val = 0x006,
116 	.test_ctl_val = 0x1c000000,
117 	.test_ctl_hi_val = 0x00004000,
118 	.pre_div_mask = BIT(12),
119 	.post_div_mask = 0x3 << 8,
120 	.post_div_val = 0x1 << 8,
121 	.main_output_mask = BIT(0),
122 	.early_output_mask = BIT(3),
123 };
124 
125 static const struct clk_parent_data pll_parent[] = {
126 	{ .fw_name = "xo" },
127 };
128 
129 static struct clk_alpha_pll pwrcl_pll = {
130 	.offset = PWRCL_REG_OFFSET,
131 	.regs = prim_pll_regs,
132 	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
133 	.clkr.hw.init = &(struct clk_init_data){
134 		.name = "pwrcl_pll",
135 		.parent_data = pll_parent,
136 		.num_parents = ARRAY_SIZE(pll_parent),
137 		.ops = &clk_alpha_pll_hwfsm_ops,
138 	},
139 };
140 
141 static struct clk_alpha_pll perfcl_pll = {
142 	.offset = PERFCL_REG_OFFSET,
143 	.regs = prim_pll_regs,
144 	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
145 	.clkr.hw.init = &(struct clk_init_data){
146 		.name = "perfcl_pll",
147 		.parent_data = pll_parent,
148 		.num_parents = ARRAY_SIZE(pll_parent),
149 		.ops = &clk_alpha_pll_hwfsm_ops,
150 	},
151 };
152 
153 static struct clk_fixed_factor pwrcl_pll_postdiv = {
154 	.mult = 1,
155 	.div = 2,
156 	.hw.init = &(struct clk_init_data){
157 		.name = "pwrcl_pll_postdiv",
158 		.parent_data = &(const struct clk_parent_data){
159 			.hw = &pwrcl_pll.clkr.hw
160 		},
161 		.num_parents = 1,
162 		.ops = &clk_fixed_factor_ops,
163 		.flags = CLK_SET_RATE_PARENT,
164 	},
165 };
166 
167 static struct clk_fixed_factor perfcl_pll_postdiv = {
168 	.mult = 1,
169 	.div = 2,
170 	.hw.init = &(struct clk_init_data){
171 		.name = "perfcl_pll_postdiv",
172 		.parent_data = &(const struct clk_parent_data){
173 			.hw = &perfcl_pll.clkr.hw
174 		},
175 		.num_parents = 1,
176 		.ops = &clk_fixed_factor_ops,
177 		.flags = CLK_SET_RATE_PARENT,
178 	},
179 };
180 
181 static struct clk_fixed_factor perfcl_pll_acd = {
182 	.mult = 1,
183 	.div = 1,
184 	.hw.init = &(struct clk_init_data){
185 		.name = "perfcl_pll_acd",
186 		.parent_data = &(const struct clk_parent_data){
187 			.hw = &perfcl_pll.clkr.hw
188 		},
189 		.num_parents = 1,
190 		.ops = &clk_fixed_factor_ops,
191 		.flags = CLK_SET_RATE_PARENT,
192 	},
193 };
194 
195 static struct clk_fixed_factor pwrcl_pll_acd = {
196 	.mult = 1,
197 	.div = 1,
198 	.hw.init = &(struct clk_init_data){
199 		.name = "pwrcl_pll_acd",
200 		.parent_data = &(const struct clk_parent_data){
201 			.hw = &pwrcl_pll.clkr.hw
202 		},
203 		.num_parents = 1,
204 		.ops = &clk_fixed_factor_ops,
205 		.flags = CLK_SET_RATE_PARENT,
206 	},
207 };
208 
209 static const struct pll_vco alt_pll_vco_modes[] = {
210 	VCO(3,  250000000,  500000000),
211 	VCO(2,  500000000,  750000000),
212 	VCO(1,  750000000, 1000000000),
213 	VCO(0, 1000000000, 2150400000),
214 };
215 
216 static const struct alpha_pll_config altpll_config = {
217 	.l = 16,
218 	.vco_val = 0x3 << 20,
219 	.vco_mask = 0x3 << 20,
220 	.config_ctl_val = 0x4001051b,
221 	.post_div_mask = 0x3 << 8,
222 	.post_div_val = 0x1 << 8,
223 	.main_output_mask = BIT(0),
224 	.early_output_mask = BIT(3),
225 };
226 
227 static struct clk_alpha_pll pwrcl_alt_pll = {
228 	.offset = PWRCL_REG_OFFSET + ALT_PLL_OFFSET,
229 	.regs = alt_pll_regs,
230 	.vco_table = alt_pll_vco_modes,
231 	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
232 	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
233 	.clkr.hw.init = &(struct clk_init_data) {
234 		.name = "pwrcl_alt_pll",
235 		.parent_data = pll_parent,
236 		.num_parents = ARRAY_SIZE(pll_parent),
237 		.ops = &clk_alpha_pll_hwfsm_ops,
238 	},
239 };
240 
241 static struct clk_alpha_pll perfcl_alt_pll = {
242 	.offset = PERFCL_REG_OFFSET + ALT_PLL_OFFSET,
243 	.regs = alt_pll_regs,
244 	.vco_table = alt_pll_vco_modes,
245 	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
246 	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
247 	.clkr.hw.init = &(struct clk_init_data) {
248 		.name = "perfcl_alt_pll",
249 		.parent_data = pll_parent,
250 		.num_parents = ARRAY_SIZE(pll_parent),
251 		.ops = &clk_alpha_pll_hwfsm_ops,
252 	},
253 };
254 
255 struct clk_cpu_8996_pmux {
256 	u32	reg;
257 	struct notifier_block nb;
258 	struct clk_regmap clkr;
259 };
260 
261 static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
262 			       void *data);
263 
264 #define to_clk_cpu_8996_pmux_nb(_nb) \
265 	container_of(_nb, struct clk_cpu_8996_pmux, nb)
266 
267 static inline struct clk_cpu_8996_pmux *to_clk_cpu_8996_pmux_hw(struct clk_hw *hw)
268 {
269 	return container_of(to_clk_regmap(hw), struct clk_cpu_8996_pmux, clkr);
270 }
271 
272 static u8 clk_cpu_8996_pmux_get_parent(struct clk_hw *hw)
273 {
274 	struct clk_regmap *clkr = to_clk_regmap(hw);
275 	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_hw(hw);
276 	u32 val;
277 
278 	regmap_read(clkr->regmap, cpuclk->reg, &val);
279 
280 	return FIELD_GET(PMUX_MASK, val);
281 }
282 
283 static int clk_cpu_8996_pmux_set_parent(struct clk_hw *hw, u8 index)
284 {
285 	struct clk_regmap *clkr = to_clk_regmap(hw);
286 	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_hw(hw);
287 	u32 val;
288 
289 	val = FIELD_PREP(PMUX_MASK, index);
290 
291 	return regmap_update_bits(clkr->regmap, cpuclk->reg, PMUX_MASK, val);
292 }
293 
294 static int clk_cpu_8996_pmux_determine_rate(struct clk_hw *hw,
295 					   struct clk_rate_request *req)
296 {
297 	struct clk_hw *parent;
298 
299 	if (req->rate < (DIV_2_THRESHOLD / 2))
300 		return -EINVAL;
301 
302 	if (req->rate < DIV_2_THRESHOLD)
303 		parent = clk_hw_get_parent_by_index(hw, SMUX_INDEX);
304 	else
305 		parent = clk_hw_get_parent_by_index(hw, ACD_INDEX);
306 	if (!parent)
307 		return -EINVAL;
308 
309 	req->best_parent_rate = clk_hw_round_rate(parent, req->rate);
310 	req->best_parent_hw = parent;
311 
312 	return 0;
313 }
314 
315 static const struct clk_ops clk_cpu_8996_pmux_ops = {
316 	.set_parent = clk_cpu_8996_pmux_set_parent,
317 	.get_parent = clk_cpu_8996_pmux_get_parent,
318 	.determine_rate = clk_cpu_8996_pmux_determine_rate,
319 };
320 
321 static const struct parent_map smux_parent_map[] = {
322 	{ .cfg = 0, }, /* xo */
323 	{ .cfg = 1, }, /* pll */
324 	{ .cfg = 3, }, /* sys_apcs_aux */
325 };
326 
327 static const struct clk_parent_data pwrcl_smux_parents[] = {
328 	{ .fw_name = "xo" },
329 	{ .hw = &pwrcl_pll_postdiv.hw },
330 	{ .fw_name = "sys_apcs_aux" },
331 };
332 
333 static const struct clk_parent_data perfcl_smux_parents[] = {
334 	{ .fw_name = "xo" },
335 	{ .hw = &perfcl_pll_postdiv.hw },
336 	{ .fw_name = "sys_apcs_aux" },
337 };
338 
339 static struct clk_regmap_mux pwrcl_smux = {
340 	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
341 	.shift = 2,
342 	.width = 2,
343 	.parent_map = smux_parent_map,
344 	.clkr.hw.init = &(struct clk_init_data) {
345 		.name = "pwrcl_smux",
346 		.parent_data = pwrcl_smux_parents,
347 		.num_parents = ARRAY_SIZE(pwrcl_smux_parents),
348 		.ops = &clk_regmap_mux_closest_ops,
349 		.flags = CLK_SET_RATE_PARENT,
350 	},
351 };
352 
353 static struct clk_regmap_mux perfcl_smux = {
354 	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
355 	.shift = 2,
356 	.width = 2,
357 	.parent_map = smux_parent_map,
358 	.clkr.hw.init = &(struct clk_init_data) {
359 		.name = "perfcl_smux",
360 		.parent_data = perfcl_smux_parents,
361 		.num_parents = ARRAY_SIZE(perfcl_smux_parents),
362 		.ops = &clk_regmap_mux_closest_ops,
363 		.flags = CLK_SET_RATE_PARENT,
364 	},
365 };
366 
367 static const struct clk_hw *pwrcl_pmux_parents[] = {
368 	[SMUX_INDEX] = &pwrcl_smux.clkr.hw,
369 	[PLL_INDEX] = &pwrcl_pll.clkr.hw,
370 	[ACD_INDEX] = &pwrcl_pll_acd.hw,
371 	[ALT_INDEX] = &pwrcl_alt_pll.clkr.hw,
372 };
373 
374 static const struct clk_hw *perfcl_pmux_parents[] = {
375 	[SMUX_INDEX] = &perfcl_smux.clkr.hw,
376 	[PLL_INDEX] = &perfcl_pll.clkr.hw,
377 	[ACD_INDEX] = &perfcl_pll_acd.hw,
378 	[ALT_INDEX] = &perfcl_alt_pll.clkr.hw,
379 };
380 
381 static struct clk_cpu_8996_pmux pwrcl_pmux = {
382 	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
383 	.nb.notifier_call = cpu_clk_notifier_cb,
384 	.clkr.hw.init = &(struct clk_init_data) {
385 		.name = "pwrcl_pmux",
386 		.parent_hws = pwrcl_pmux_parents,
387 		.num_parents = ARRAY_SIZE(pwrcl_pmux_parents),
388 		.ops = &clk_cpu_8996_pmux_ops,
389 		/* CPU clock is critical and should never be gated */
390 		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
391 	},
392 };
393 
394 static struct clk_cpu_8996_pmux perfcl_pmux = {
395 	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
396 	.nb.notifier_call = cpu_clk_notifier_cb,
397 	.clkr.hw.init = &(struct clk_init_data) {
398 		.name = "perfcl_pmux",
399 		.parent_hws = perfcl_pmux_parents,
400 		.num_parents = ARRAY_SIZE(perfcl_pmux_parents),
401 		.ops = &clk_cpu_8996_pmux_ops,
402 		/* CPU clock is critical and should never be gated */
403 		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
404 	},
405 };
406 
407 static const struct regmap_config cpu_msm8996_regmap_config = {
408 	.reg_bits		= 32,
409 	.reg_stride		= 4,
410 	.val_bits		= 32,
411 	.max_register		= 0x80210,
412 	.fast_io		= true,
413 	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
414 };
415 
416 static struct clk_hw *cpu_msm8996_hw_clks[] = {
417 	&pwrcl_pll_postdiv.hw,
418 	&perfcl_pll_postdiv.hw,
419 	&pwrcl_pll_acd.hw,
420 	&perfcl_pll_acd.hw,
421 };
422 
423 static struct clk_regmap *cpu_msm8996_clks[] = {
424 	&pwrcl_pll.clkr,
425 	&perfcl_pll.clkr,
426 	&pwrcl_alt_pll.clkr,
427 	&perfcl_alt_pll.clkr,
428 	&pwrcl_smux.clkr,
429 	&perfcl_smux.clkr,
430 	&pwrcl_pmux.clkr,
431 	&perfcl_pmux.clkr,
432 };
433 
434 static void qcom_cpu_clk_msm8996_acd_init(struct regmap *regmap);
435 
436 static int qcom_cpu_clk_msm8996_register_clks(struct device *dev,
437 					      struct regmap *regmap)
438 {
439 	int i, ret;
440 
441 	/* Select GPLL0 for 300MHz for both clusters */
442 	regmap_write(regmap, PERFCL_REG_OFFSET + MUX_OFFSET, 0xc);
443 	regmap_write(regmap, PWRCL_REG_OFFSET + MUX_OFFSET, 0xc);
444 
445 	/* Ensure write goes through before PLLs are reconfigured */
446 	udelay(5);
447 
448 	/* Set the auto clock sel always-on source to GPLL0/2 (300MHz) */
449 	regmap_update_bits(regmap, PWRCL_REG_OFFSET + MUX_OFFSET,
450 			   MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK,
451 			   MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL);
452 	regmap_update_bits(regmap, PERFCL_REG_OFFSET + MUX_OFFSET,
453 			   MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK,
454 			   MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL);
455 
456 	clk_alpha_pll_configure(&pwrcl_pll, regmap, &hfpll_config);
457 	clk_alpha_pll_configure(&perfcl_pll, regmap, &hfpll_config);
458 	clk_alpha_pll_configure(&pwrcl_alt_pll, regmap, &altpll_config);
459 	clk_alpha_pll_configure(&perfcl_alt_pll, regmap, &altpll_config);
460 
461 	/* Wait for PLL(s) to lock */
462 	udelay(50);
463 
464 	/* Enable auto clock selection for both clusters */
465 	regmap_update_bits(regmap, PWRCL_REG_OFFSET + CLK_CTL_OFFSET,
466 			   CLK_CTL_AUTO_CLK_SEL, CLK_CTL_AUTO_CLK_SEL);
467 	regmap_update_bits(regmap, PERFCL_REG_OFFSET + CLK_CTL_OFFSET,
468 			   CLK_CTL_AUTO_CLK_SEL, CLK_CTL_AUTO_CLK_SEL);
469 
470 	/* Ensure write goes through before muxes are switched */
471 	udelay(5);
472 
473 	qcom_cpu_clk_msm8996_acd_init(regmap);
474 
475 	/* Pulse swallower and soft-start settings */
476 	regmap_write(regmap, PWRCL_REG_OFFSET + PSCTL_OFFSET, 0x00030005);
477 	regmap_write(regmap, PERFCL_REG_OFFSET + PSCTL_OFFSET, 0x00030005);
478 
479 	/* Switch clusters to use the ACD leg */
480 	regmap_write(regmap, PWRCL_REG_OFFSET + MUX_OFFSET, 0x32);
481 	regmap_write(regmap, PERFCL_REG_OFFSET + MUX_OFFSET, 0x32);
482 
483 	for (i = 0; i < ARRAY_SIZE(cpu_msm8996_hw_clks); i++) {
484 		ret = devm_clk_hw_register(dev, cpu_msm8996_hw_clks[i]);
485 		if (ret)
486 			return ret;
487 	}
488 
489 	for (i = 0; i < ARRAY_SIZE(cpu_msm8996_clks); i++) {
490 		ret = devm_clk_register_regmap(dev, cpu_msm8996_clks[i]);
491 		if (ret)
492 			return ret;
493 	}
494 
495 	/* Enable alt PLLs */
496 	clk_prepare_enable(pwrcl_alt_pll.clkr.hw.clk);
497 	clk_prepare_enable(perfcl_alt_pll.clkr.hw.clk);
498 
499 	devm_clk_notifier_register(dev, pwrcl_pmux.clkr.hw.clk, &pwrcl_pmux.nb);
500 	devm_clk_notifier_register(dev, perfcl_pmux.clkr.hw.clk, &perfcl_pmux.nb);
501 
502 	return ret;
503 }
504 
505 #define CPU_CLUSTER_AFFINITY_MASK 0xf00
506 #define PWRCL_AFFINITY_MASK 0x000
507 #define PERFCL_AFFINITY_MASK 0x100
508 
509 #define L2ACDCR_REG 0x580ULL
510 #define L2ACDTD_REG 0x581ULL
511 #define L2ACDDVMRC_REG 0x584ULL
512 #define L2ACDSSCR_REG 0x589ULL
513 
514 static DEFINE_SPINLOCK(qcom_clk_acd_lock);
515 
516 static void qcom_cpu_clk_msm8996_acd_init(struct regmap *regmap)
517 {
518 	u64 hwid;
519 	u32 val;
520 	unsigned long flags;
521 
522 	spin_lock_irqsave(&qcom_clk_acd_lock, flags);
523 
524 	val = kryo_l2_get_indirect_reg(L2ACDTD_REG);
525 	if (val == 0x00006a11)
526 		goto out;
527 
528 	kryo_l2_set_indirect_reg(L2ACDTD_REG, 0x00006a11);
529 	kryo_l2_set_indirect_reg(L2ACDDVMRC_REG, 0x000e0f0f);
530 	kryo_l2_set_indirect_reg(L2ACDSSCR_REG, 0x00000601);
531 
532 	kryo_l2_set_indirect_reg(L2ACDCR_REG, 0x002c5ffd);
533 
534 	hwid = read_cpuid_mpidr();
535 	if ((hwid & CPU_CLUSTER_AFFINITY_MASK) == PWRCL_AFFINITY_MASK)
536 		regmap_write(regmap, PWRCL_REG_OFFSET + SSSCTL_OFFSET, 0xf);
537 	else
538 		regmap_write(regmap, PERFCL_REG_OFFSET + SSSCTL_OFFSET, 0xf);
539 
540 out:
541 	spin_unlock_irqrestore(&qcom_clk_acd_lock, flags);
542 }
543 
544 static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
545 			       void *data)
546 {
547 	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_nb(nb);
548 	struct clk_notifier_data *cnd = data;
549 
550 	switch (event) {
551 	case PRE_RATE_CHANGE:
552 		qcom_cpu_clk_msm8996_acd_init(cpuclk->clkr.regmap);
553 
554 		/*
555 		 * Avoid overvolting. clk_core_set_rate_nolock() walks from top
556 		 * to bottom, so it will change the rate of the PLL before
557 		 * chaging the parent of PMUX. This can result in pmux getting
558 		 * clocked twice the expected rate.
559 		 *
560 		 * Manually switch to PLL/2 here.
561 		 */
562 		if (cnd->new_rate < DIV_2_THRESHOLD &&
563 		    cnd->old_rate > DIV_2_THRESHOLD)
564 			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, SMUX_INDEX);
565 
566 		break;
567 	case ABORT_RATE_CHANGE:
568 		/* Revert manual change */
569 		if (cnd->new_rate < DIV_2_THRESHOLD &&
570 		    cnd->old_rate > DIV_2_THRESHOLD)
571 			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, ACD_INDEX);
572 		break;
573 	default:
574 		break;
575 	}
576 
577 	return NOTIFY_OK;
578 };
579 
580 static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)
581 {
582 	static void __iomem *base;
583 	struct regmap *regmap;
584 	struct clk_hw_onecell_data *data;
585 	struct device *dev = &pdev->dev;
586 	int ret;
587 
588 	data = devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
589 	if (!data)
590 		return -ENOMEM;
591 
592 	base = devm_platform_ioremap_resource(pdev, 0);
593 	if (IS_ERR(base))
594 		return PTR_ERR(base);
595 
596 	regmap = devm_regmap_init_mmio(dev, base, &cpu_msm8996_regmap_config);
597 	if (IS_ERR(regmap))
598 		return PTR_ERR(regmap);
599 
600 	ret = qcom_cpu_clk_msm8996_register_clks(dev, regmap);
601 	if (ret)
602 		return ret;
603 
604 	data->hws[0] = &pwrcl_pmux.clkr.hw;
605 	data->hws[1] = &perfcl_pmux.clkr.hw;
606 	data->num = 2;
607 
608 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, data);
609 }
610 
611 static const struct of_device_id qcom_cpu_clk_msm8996_match_table[] = {
612 	{ .compatible = "qcom,msm8996-apcc" },
613 	{}
614 };
615 MODULE_DEVICE_TABLE(of, qcom_cpu_clk_msm8996_match_table);
616 
617 static struct platform_driver qcom_cpu_clk_msm8996_driver = {
618 	.probe = qcom_cpu_clk_msm8996_driver_probe,
619 	.driver = {
620 		.name = "qcom-msm8996-apcc",
621 		.of_match_table = qcom_cpu_clk_msm8996_match_table,
622 	},
623 };
624 module_platform_driver(qcom_cpu_clk_msm8996_driver);
625 
626 MODULE_DESCRIPTION("QCOM MSM8996 CPU Clock Driver");
627 MODULE_LICENSE("GPL v2");
628