xref: /openbmc/linux/drivers/clk/qcom/clk-cpu-8996.c (revision 63705da3)
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  *                              |       |
16  *                    PLL/2     | SMUX  +----+
17  *                      +------->1      |    |
18  *                      |       |       |    |
19  *                      |       +-------+    |    +-------+
20  *                      |                    +---->0      |
21  *                      |                         |       |
22  * +---------------+    |             +----------->1      | CPU clk
23  * |Primary PLL    +----+ PLL_EARLY   |           |       +------>
24  * |               +------+-----------+    +------>2 PMUX |
25  * +---------------+      |                |      |       |
26  *                        |   +------+     |   +-->3      |
27  *                        +--^+  ACD +-----+   |  +-------+
28  * +---------------+          +------+         |
29  * |Alt PLL        |                           |
30  * |               +---------------------------+
31  * +---------------+         PLL_EARLY
32  *
33  * The primary PLL is what drives the CPU clk, except for times
34  * when we are reprogramming the PLL itself (for rate changes) when
35  * we temporarily switch to an alternate PLL.
36  *
37  * The primary PLL operates on a single VCO range, between 600MHz
38  * and 3GHz. However the CPUs do support OPPs with frequencies
39  * between 300MHz and 600MHz. In order to support running the CPUs
40  * at those frequencies we end up having to lock the PLL at twice
41  * the rate and drive the CPU clk via the PLL/2 output and SMUX.
42  *
43  * So for frequencies above 600MHz we follow the following path
44  *  Primary PLL --> PLL_EARLY --> PMUX(1) --> CPU clk
45  * and for frequencies between 300MHz and 600MHz we follow
46  *  Primary PLL --> PLL/2 --> SMUX(1) --> PMUX(0) --> CPU clk
47  *
48  * ACD stands for Adaptive Clock Distribution and is used to
49  * detect voltage droops.
50  */
51 
52 #include <linux/clk.h>
53 #include <linux/clk-provider.h>
54 #include <linux/io.h>
55 #include <linux/module.h>
56 #include <linux/platform_device.h>
57 #include <linux/regmap.h>
58 #include <soc/qcom/kryo-l2-accessors.h>
59 
60 #include "clk-alpha-pll.h"
61 #include "clk-regmap.h"
62 
63 enum _pmux_input {
64 	DIV_2_INDEX = 0,
65 	PLL_INDEX,
66 	ACD_INDEX,
67 	ALT_INDEX,
68 	NUM_OF_PMUX_INPUTS
69 };
70 
71 #define DIV_2_THRESHOLD		600000000
72 #define PWRCL_REG_OFFSET 0x0
73 #define PERFCL_REG_OFFSET 0x80000
74 #define MUX_OFFSET	0x40
75 #define ALT_PLL_OFFSET	0x100
76 #define SSSCTL_OFFSET 0x160
77 
78 static const u8 prim_pll_regs[PLL_OFF_MAX_REGS] = {
79 	[PLL_OFF_L_VAL] = 0x04,
80 	[PLL_OFF_ALPHA_VAL] = 0x08,
81 	[PLL_OFF_USER_CTL] = 0x10,
82 	[PLL_OFF_CONFIG_CTL] = 0x18,
83 	[PLL_OFF_CONFIG_CTL_U] = 0x1c,
84 	[PLL_OFF_TEST_CTL] = 0x20,
85 	[PLL_OFF_TEST_CTL_U] = 0x24,
86 	[PLL_OFF_STATUS] = 0x28,
87 };
88 
89 static const u8 alt_pll_regs[PLL_OFF_MAX_REGS] = {
90 	[PLL_OFF_L_VAL] = 0x04,
91 	[PLL_OFF_ALPHA_VAL] = 0x08,
92 	[PLL_OFF_ALPHA_VAL_U] = 0x0c,
93 	[PLL_OFF_USER_CTL] = 0x10,
94 	[PLL_OFF_USER_CTL_U] = 0x14,
95 	[PLL_OFF_CONFIG_CTL] = 0x18,
96 	[PLL_OFF_TEST_CTL] = 0x20,
97 	[PLL_OFF_TEST_CTL_U] = 0x24,
98 	[PLL_OFF_STATUS] = 0x28,
99 };
100 
101 /* PLLs */
102 
103 static const struct alpha_pll_config hfpll_config = {
104 	.l = 60,
105 	.config_ctl_val = 0x200d4aa8,
106 	.config_ctl_hi_val = 0x006,
107 	.pre_div_mask = BIT(12),
108 	.post_div_mask = 0x3 << 8,
109 	.post_div_val = 0x1 << 8,
110 	.main_output_mask = BIT(0),
111 	.early_output_mask = BIT(3),
112 };
113 
114 static struct clk_alpha_pll perfcl_pll = {
115 	.offset = PERFCL_REG_OFFSET,
116 	.regs = prim_pll_regs,
117 	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
118 	.clkr.hw.init = &(struct clk_init_data){
119 		.name = "perfcl_pll",
120 		.parent_names = (const char *[]){ "xo" },
121 		.num_parents = 1,
122 		.ops = &clk_alpha_pll_huayra_ops,
123 	},
124 };
125 
126 static struct clk_alpha_pll pwrcl_pll = {
127 	.offset = PWRCL_REG_OFFSET,
128 	.regs = prim_pll_regs,
129 	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
130 	.clkr.hw.init = &(struct clk_init_data){
131 		.name = "pwrcl_pll",
132 		.parent_names = (const char *[]){ "xo" },
133 		.num_parents = 1,
134 		.ops = &clk_alpha_pll_huayra_ops,
135 	},
136 };
137 
138 static const struct pll_vco alt_pll_vco_modes[] = {
139 	VCO(3,  250000000,  500000000),
140 	VCO(2,  500000000,  750000000),
141 	VCO(1,  750000000, 1000000000),
142 	VCO(0, 1000000000, 2150400000),
143 };
144 
145 static const struct alpha_pll_config altpll_config = {
146 	.l = 16,
147 	.vco_val = 0x3 << 20,
148 	.vco_mask = 0x3 << 20,
149 	.config_ctl_val = 0x4001051b,
150 	.post_div_mask = 0x3 << 8,
151 	.post_div_val = 0x1 << 8,
152 	.main_output_mask = BIT(0),
153 	.early_output_mask = BIT(3),
154 };
155 
156 static struct clk_alpha_pll perfcl_alt_pll = {
157 	.offset = PERFCL_REG_OFFSET + ALT_PLL_OFFSET,
158 	.regs = alt_pll_regs,
159 	.vco_table = alt_pll_vco_modes,
160 	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
161 	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
162 	.clkr.hw.init = &(struct clk_init_data) {
163 		.name = "perfcl_alt_pll",
164 		.parent_names = (const char *[]){ "xo" },
165 		.num_parents = 1,
166 		.ops = &clk_alpha_pll_hwfsm_ops,
167 	},
168 };
169 
170 static struct clk_alpha_pll pwrcl_alt_pll = {
171 	.offset = PWRCL_REG_OFFSET + ALT_PLL_OFFSET,
172 	.regs = alt_pll_regs,
173 	.vco_table = alt_pll_vco_modes,
174 	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
175 	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
176 	.clkr.hw.init = &(struct clk_init_data) {
177 		.name = "pwrcl_alt_pll",
178 		.parent_names = (const char *[]){ "xo" },
179 		.num_parents = 1,
180 		.ops = &clk_alpha_pll_hwfsm_ops,
181 	},
182 };
183 
184 struct clk_cpu_8996_mux {
185 	u32	reg;
186 	u8	shift;
187 	u8	width;
188 	struct notifier_block nb;
189 	struct clk_hw	*pll;
190 	struct clk_hw	*pll_div_2;
191 	struct clk_regmap clkr;
192 };
193 
194 static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
195 			       void *data);
196 
197 #define to_clk_cpu_8996_mux_nb(_nb) \
198 	container_of(_nb, struct clk_cpu_8996_mux, nb)
199 
200 static inline struct clk_cpu_8996_mux *to_clk_cpu_8996_mux_hw(struct clk_hw *hw)
201 {
202 	return container_of(to_clk_regmap(hw), struct clk_cpu_8996_mux, clkr);
203 }
204 
205 static u8 clk_cpu_8996_mux_get_parent(struct clk_hw *hw)
206 {
207 	struct clk_regmap *clkr = to_clk_regmap(hw);
208 	struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
209 	u32 mask = GENMASK(cpuclk->width - 1, 0);
210 	u32 val;
211 
212 	regmap_read(clkr->regmap, cpuclk->reg, &val);
213 	val >>= cpuclk->shift;
214 
215 	return val & mask;
216 }
217 
218 static int clk_cpu_8996_mux_set_parent(struct clk_hw *hw, u8 index)
219 {
220 	struct clk_regmap *clkr = to_clk_regmap(hw);
221 	struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
222 	u32 mask = GENMASK(cpuclk->width + cpuclk->shift - 1, cpuclk->shift);
223 	u32 val;
224 
225 	val = index;
226 	val <<= cpuclk->shift;
227 
228 	return regmap_update_bits(clkr->regmap, cpuclk->reg, mask, val);
229 }
230 
231 static int clk_cpu_8996_mux_determine_rate(struct clk_hw *hw,
232 					   struct clk_rate_request *req)
233 {
234 	struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
235 	struct clk_hw *parent = cpuclk->pll;
236 
237 	if (cpuclk->pll_div_2 && req->rate < DIV_2_THRESHOLD) {
238 		if (req->rate < (DIV_2_THRESHOLD / 2))
239 			return -EINVAL;
240 
241 		parent = cpuclk->pll_div_2;
242 	}
243 
244 	req->best_parent_rate = clk_hw_round_rate(parent, req->rate);
245 	req->best_parent_hw = parent;
246 
247 	return 0;
248 }
249 
250 static const struct clk_ops clk_cpu_8996_mux_ops = {
251 	.set_parent = clk_cpu_8996_mux_set_parent,
252 	.get_parent = clk_cpu_8996_mux_get_parent,
253 	.determine_rate = clk_cpu_8996_mux_determine_rate,
254 };
255 
256 static struct clk_cpu_8996_mux pwrcl_smux = {
257 	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
258 	.shift = 2,
259 	.width = 2,
260 	.clkr.hw.init = &(struct clk_init_data) {
261 		.name = "pwrcl_smux",
262 		.parent_names = (const char *[]){
263 			"xo",
264 			"pwrcl_pll_main",
265 		},
266 		.num_parents = 2,
267 		.ops = &clk_cpu_8996_mux_ops,
268 		.flags = CLK_SET_RATE_PARENT,
269 	},
270 };
271 
272 static struct clk_cpu_8996_mux perfcl_smux = {
273 	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
274 	.shift = 2,
275 	.width = 2,
276 	.clkr.hw.init = &(struct clk_init_data) {
277 		.name = "perfcl_smux",
278 		.parent_names = (const char *[]){
279 			"xo",
280 			"perfcl_pll_main",
281 		},
282 		.num_parents = 2,
283 		.ops = &clk_cpu_8996_mux_ops,
284 		.flags = CLK_SET_RATE_PARENT,
285 	},
286 };
287 
288 static struct clk_cpu_8996_mux pwrcl_pmux = {
289 	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
290 	.shift = 0,
291 	.width = 2,
292 	.pll = &pwrcl_pll.clkr.hw,
293 	.pll_div_2 = &pwrcl_smux.clkr.hw,
294 	.nb.notifier_call = cpu_clk_notifier_cb,
295 	.clkr.hw.init = &(struct clk_init_data) {
296 		.name = "pwrcl_pmux",
297 		.parent_names = (const char *[]){
298 			"pwrcl_smux",
299 			"pwrcl_pll",
300 			"pwrcl_pll_acd",
301 			"pwrcl_alt_pll",
302 		},
303 		.num_parents = 4,
304 		.ops = &clk_cpu_8996_mux_ops,
305 		/* CPU clock is critical and should never be gated */
306 		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
307 	},
308 };
309 
310 static struct clk_cpu_8996_mux perfcl_pmux = {
311 	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
312 	.shift = 0,
313 	.width = 2,
314 	.pll = &perfcl_pll.clkr.hw,
315 	.pll_div_2 = &perfcl_smux.clkr.hw,
316 	.nb.notifier_call = cpu_clk_notifier_cb,
317 	.clkr.hw.init = &(struct clk_init_data) {
318 		.name = "perfcl_pmux",
319 		.parent_names = (const char *[]){
320 			"perfcl_smux",
321 			"perfcl_pll",
322 			"perfcl_pll_acd",
323 			"perfcl_alt_pll",
324 		},
325 		.num_parents = 4,
326 		.ops = &clk_cpu_8996_mux_ops,
327 		/* CPU clock is critical and should never be gated */
328 		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
329 	},
330 };
331 
332 static const struct regmap_config cpu_msm8996_regmap_config = {
333 	.reg_bits		= 32,
334 	.reg_stride		= 4,
335 	.val_bits		= 32,
336 	.max_register		= 0x80210,
337 	.fast_io		= true,
338 	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
339 };
340 
341 static struct clk_regmap *cpu_msm8996_clks[] = {
342 	&perfcl_pll.clkr,
343 	&pwrcl_pll.clkr,
344 	&perfcl_alt_pll.clkr,
345 	&pwrcl_alt_pll.clkr,
346 	&perfcl_smux.clkr,
347 	&pwrcl_smux.clkr,
348 	&perfcl_pmux.clkr,
349 	&pwrcl_pmux.clkr,
350 };
351 
352 static int qcom_cpu_clk_msm8996_register_clks(struct device *dev,
353 					      struct regmap *regmap)
354 {
355 	int i, ret;
356 
357 	perfcl_smux.pll = clk_hw_register_fixed_factor(dev, "perfcl_pll_main",
358 						       "perfcl_pll",
359 						       CLK_SET_RATE_PARENT,
360 						       1, 2);
361 	if (IS_ERR(perfcl_smux.pll)) {
362 		dev_err(dev, "Failed to initialize perfcl_pll_main\n");
363 		return PTR_ERR(perfcl_smux.pll);
364 	}
365 
366 	pwrcl_smux.pll = clk_hw_register_fixed_factor(dev, "pwrcl_pll_main",
367 						      "pwrcl_pll",
368 						      CLK_SET_RATE_PARENT,
369 						      1, 2);
370 	if (IS_ERR(pwrcl_smux.pll)) {
371 		dev_err(dev, "Failed to initialize pwrcl_pll_main\n");
372 		clk_hw_unregister(perfcl_smux.pll);
373 		return PTR_ERR(pwrcl_smux.pll);
374 	}
375 
376 	for (i = 0; i < ARRAY_SIZE(cpu_msm8996_clks); i++) {
377 		ret = devm_clk_register_regmap(dev, cpu_msm8996_clks[i]);
378 		if (ret) {
379 			clk_hw_unregister(perfcl_smux.pll);
380 			clk_hw_unregister(pwrcl_smux.pll);
381 			return ret;
382 		}
383 	}
384 
385 	clk_alpha_pll_configure(&perfcl_pll, regmap, &hfpll_config);
386 	clk_alpha_pll_configure(&pwrcl_pll, regmap, &hfpll_config);
387 	clk_alpha_pll_configure(&perfcl_alt_pll, regmap, &altpll_config);
388 	clk_alpha_pll_configure(&pwrcl_alt_pll, regmap, &altpll_config);
389 
390 	/* Enable alt PLLs */
391 	clk_prepare_enable(pwrcl_alt_pll.clkr.hw.clk);
392 	clk_prepare_enable(perfcl_alt_pll.clkr.hw.clk);
393 
394 	clk_notifier_register(pwrcl_pmux.clkr.hw.clk, &pwrcl_pmux.nb);
395 	clk_notifier_register(perfcl_pmux.clkr.hw.clk, &perfcl_pmux.nb);
396 
397 	return ret;
398 }
399 
400 static int qcom_cpu_clk_msm8996_unregister_clks(void)
401 {
402 	int ret = 0;
403 
404 	ret = clk_notifier_unregister(pwrcl_pmux.clkr.hw.clk, &pwrcl_pmux.nb);
405 	if (ret)
406 		return ret;
407 
408 	ret = clk_notifier_unregister(perfcl_pmux.clkr.hw.clk, &perfcl_pmux.nb);
409 	if (ret)
410 		return ret;
411 
412 	clk_hw_unregister(perfcl_smux.pll);
413 	clk_hw_unregister(pwrcl_smux.pll);
414 
415 	return 0;
416 }
417 
418 #define CPU_AFINITY_MASK 0xFFF
419 #define PWRCL_CPU_REG_MASK 0x3
420 #define PERFCL_CPU_REG_MASK 0x103
421 
422 #define L2ACDCR_REG 0x580ULL
423 #define L2ACDTD_REG 0x581ULL
424 #define L2ACDDVMRC_REG 0x584ULL
425 #define L2ACDSSCR_REG 0x589ULL
426 
427 static DEFINE_SPINLOCK(qcom_clk_acd_lock);
428 static void __iomem *base;
429 
430 static void qcom_cpu_clk_msm8996_acd_init(void __iomem *base)
431 {
432 	u64 hwid;
433 	unsigned long flags;
434 
435 	spin_lock_irqsave(&qcom_clk_acd_lock, flags);
436 
437 	hwid = read_cpuid_mpidr() & CPU_AFINITY_MASK;
438 
439 	kryo_l2_set_indirect_reg(L2ACDTD_REG, 0x00006a11);
440 	kryo_l2_set_indirect_reg(L2ACDDVMRC_REG, 0x000e0f0f);
441 	kryo_l2_set_indirect_reg(L2ACDSSCR_REG, 0x00000601);
442 
443 	if (PWRCL_CPU_REG_MASK == (hwid | PWRCL_CPU_REG_MASK)) {
444 		writel(0xf, base + PWRCL_REG_OFFSET + SSSCTL_OFFSET);
445 		kryo_l2_set_indirect_reg(L2ACDCR_REG, 0x002c5ffd);
446 	}
447 
448 	if (PERFCL_CPU_REG_MASK == (hwid | PERFCL_CPU_REG_MASK)) {
449 		kryo_l2_set_indirect_reg(L2ACDCR_REG, 0x002c5ffd);
450 		writel(0xf, base + PERFCL_REG_OFFSET + SSSCTL_OFFSET);
451 	}
452 
453 	spin_unlock_irqrestore(&qcom_clk_acd_lock, flags);
454 }
455 
456 static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
457 			       void *data)
458 {
459 	struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_nb(nb);
460 	struct clk_notifier_data *cnd = data;
461 	int ret;
462 
463 	switch (event) {
464 	case PRE_RATE_CHANGE:
465 		ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw, ALT_INDEX);
466 		qcom_cpu_clk_msm8996_acd_init(base);
467 		break;
468 	case POST_RATE_CHANGE:
469 		if (cnd->new_rate < DIV_2_THRESHOLD)
470 			ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw,
471 							  DIV_2_INDEX);
472 		else
473 			ret = clk_cpu_8996_mux_set_parent(&cpuclk->clkr.hw,
474 							  ACD_INDEX);
475 		break;
476 	default:
477 		ret = 0;
478 		break;
479 	}
480 
481 	return notifier_from_errno(ret);
482 };
483 
484 static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)
485 {
486 	struct regmap *regmap;
487 	struct clk_hw_onecell_data *data;
488 	struct device *dev = &pdev->dev;
489 	int ret;
490 
491 	data = devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
492 	if (!data)
493 		return -ENOMEM;
494 
495 	base = devm_platform_ioremap_resource(pdev, 0);
496 	if (IS_ERR(base))
497 		return PTR_ERR(base);
498 
499 	regmap = devm_regmap_init_mmio(dev, base, &cpu_msm8996_regmap_config);
500 	if (IS_ERR(regmap))
501 		return PTR_ERR(regmap);
502 
503 	ret = qcom_cpu_clk_msm8996_register_clks(dev, regmap);
504 	if (ret)
505 		return ret;
506 
507 	qcom_cpu_clk_msm8996_acd_init(base);
508 
509 	data->hws[0] = &pwrcl_pmux.clkr.hw;
510 	data->hws[1] = &perfcl_pmux.clkr.hw;
511 	data->num = 2;
512 
513 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, data);
514 }
515 
516 static int qcom_cpu_clk_msm8996_driver_remove(struct platform_device *pdev)
517 {
518 	return qcom_cpu_clk_msm8996_unregister_clks();
519 }
520 
521 static const struct of_device_id qcom_cpu_clk_msm8996_match_table[] = {
522 	{ .compatible = "qcom,msm8996-apcc" },
523 	{}
524 };
525 MODULE_DEVICE_TABLE(of, qcom_cpu_clk_msm8996_match_table);
526 
527 static struct platform_driver qcom_cpu_clk_msm8996_driver = {
528 	.probe = qcom_cpu_clk_msm8996_driver_probe,
529 	.remove = qcom_cpu_clk_msm8996_driver_remove,
530 	.driver = {
531 		.name = "qcom-msm8996-apcc",
532 		.of_match_table = qcom_cpu_clk_msm8996_match_table,
533 	},
534 };
535 module_platform_driver(qcom_cpu_clk_msm8996_driver);
536 
537 MODULE_DESCRIPTION("QCOM MSM8996 CPU Clock Driver");
538 MODULE_LICENSE("GPL v2");
539