1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2020 SiFive, Inc.
4 * Copyright (C) 2020 Zong Li
5 */
6
7#include <linux/clkdev.h>
8#include <linux/delay.h>
9#include <linux/io.h>
10#include <linux/of.h>
11#include "sifive-prci.h"
12#include "fu540-prci.h"
13#include "fu740-prci.h"
14
15/*
16 * Private functions
17 */
18
19/**
20 * __prci_readl() - read from a PRCI register
21 * @pd: PRCI context
22 * @offs: register offset to read from (in bytes, from PRCI base address)
23 *
24 * Read the register located at offset @offs from the base virtual
25 * address of the PRCI register target described by @pd, and return
26 * the value to the caller.
27 *
28 * Context: Any context.
29 *
30 * Return: the contents of the register described by @pd and @offs.
31 */
32static u32 __prci_readl(struct __prci_data *pd, u32 offs)
33{
34	return readl_relaxed(pd->va + offs);
35}
36
37static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd)
38{
39	writel_relaxed(v, pd->va + offs);
40}
41
42/* WRPLL-related private functions */
43
44/**
45 * __prci_wrpll_unpack() - unpack WRPLL configuration registers into parameters
46 * @c: ptr to a struct wrpll_cfg record to write config into
47 * @r: value read from the PRCI PLL configuration register
48 *
49 * Given a value @r read from an FU740 PRCI PLL configuration register,
50 * split it into fields and populate it into the WRPLL configuration record
51 * pointed to by @c.
52 *
53 * The COREPLLCFG0 macros are used below, but the other *PLLCFG0 macros
54 * have the same register layout.
55 *
56 * Context: Any context.
57 */
58static void __prci_wrpll_unpack(struct wrpll_cfg *c, u32 r)
59{
60	u32 v;
61
62	v = r & PRCI_COREPLLCFG0_DIVR_MASK;
63	v >>= PRCI_COREPLLCFG0_DIVR_SHIFT;
64	c->divr = v;
65
66	v = r & PRCI_COREPLLCFG0_DIVF_MASK;
67	v >>= PRCI_COREPLLCFG0_DIVF_SHIFT;
68	c->divf = v;
69
70	v = r & PRCI_COREPLLCFG0_DIVQ_MASK;
71	v >>= PRCI_COREPLLCFG0_DIVQ_SHIFT;
72	c->divq = v;
73
74	v = r & PRCI_COREPLLCFG0_RANGE_MASK;
75	v >>= PRCI_COREPLLCFG0_RANGE_SHIFT;
76	c->range = v;
77
78	c->flags &=
79	    (WRPLL_FLAGS_INT_FEEDBACK_MASK | WRPLL_FLAGS_EXT_FEEDBACK_MASK);
80
81	/* external feedback mode not supported */
82	c->flags |= WRPLL_FLAGS_INT_FEEDBACK_MASK;
83}
84
85/**
86 * __prci_wrpll_pack() - pack PLL configuration parameters into a register value
87 * @c: pointer to a struct wrpll_cfg record containing the PLL's cfg
88 *
89 * Using a set of WRPLL configuration values pointed to by @c,
90 * assemble a PRCI PLL configuration register value, and return it to
91 * the caller.
92 *
93 * Context: Any context.  Caller must ensure that the contents of the
94 *          record pointed to by @c do not change during the execution
95 *          of this function.
96 *
97 * Returns: a value suitable for writing into a PRCI PLL configuration
98 *          register
99 */
100static u32 __prci_wrpll_pack(const struct wrpll_cfg *c)
101{
102	u32 r = 0;
103
104	r |= c->divr << PRCI_COREPLLCFG0_DIVR_SHIFT;
105	r |= c->divf << PRCI_COREPLLCFG0_DIVF_SHIFT;
106	r |= c->divq << PRCI_COREPLLCFG0_DIVQ_SHIFT;
107	r |= c->range << PRCI_COREPLLCFG0_RANGE_SHIFT;
108
109	/* external feedback mode not supported */
110	r |= PRCI_COREPLLCFG0_FSE_MASK;
111
112	return r;
113}
114
115/**
116 * __prci_wrpll_read_cfg0() - read the WRPLL configuration from the PRCI
117 * @pd: PRCI context
118 * @pwd: PRCI WRPLL metadata
119 *
120 * Read the current configuration of the PLL identified by @pwd from
121 * the PRCI identified by @pd, and store it into the local configuration
122 * cache in @pwd.
123 *
124 * Context: Any context.  Caller must prevent the records pointed to by
125 *          @pd and @pwd from changing during execution.
126 */
127static void __prci_wrpll_read_cfg0(struct __prci_data *pd,
128				   struct __prci_wrpll_data *pwd)
129{
130	__prci_wrpll_unpack(&pwd->c, __prci_readl(pd, pwd->cfg0_offs));
131}
132
133/**
134 * __prci_wrpll_write_cfg0() - write WRPLL configuration into the PRCI
135 * @pd: PRCI context
136 * @pwd: PRCI WRPLL metadata
137 * @c: WRPLL configuration record to write
138 *
139 * Write the WRPLL configuration described by @c into the WRPLL
140 * configuration register identified by @pwd in the PRCI instance
141 * described by @c.  Make a cached copy of the WRPLL's current
142 * configuration so it can be used by other code.
143 *
144 * Context: Any context.  Caller must prevent the records pointed to by
145 *          @pd and @pwd from changing during execution.
146 */
147static void __prci_wrpll_write_cfg0(struct __prci_data *pd,
148				    struct __prci_wrpll_data *pwd,
149				    struct wrpll_cfg *c)
150{
151	__prci_writel(__prci_wrpll_pack(c), pwd->cfg0_offs, pd);
152
153	memcpy(&pwd->c, c, sizeof(*c));
154}
155
156/**
157 * __prci_wrpll_write_cfg1() - write Clock enable/disable configuration
158 * into the PRCI
159 * @pd: PRCI context
160 * @pwd: PRCI WRPLL metadata
161 * @enable: Clock enable or disable value
162 */
163static void __prci_wrpll_write_cfg1(struct __prci_data *pd,
164				    struct __prci_wrpll_data *pwd,
165				    u32 enable)
166{
167	__prci_writel(enable, pwd->cfg1_offs, pd);
168}
169
170/*
171 * Linux clock framework integration
172 *
173 * See the Linux clock framework documentation for more information on
174 * these functions.
175 */
176
177unsigned long sifive_prci_wrpll_recalc_rate(struct clk_hw *hw,
178					    unsigned long parent_rate)
179{
180	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
181	struct __prci_wrpll_data *pwd = pc->pwd;
182
183	return wrpll_calc_output_rate(&pwd->c, parent_rate);
184}
185
186long sifive_prci_wrpll_round_rate(struct clk_hw *hw,
187				  unsigned long rate,
188				  unsigned long *parent_rate)
189{
190	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
191	struct __prci_wrpll_data *pwd = pc->pwd;
192	struct wrpll_cfg c;
193
194	memcpy(&c, &pwd->c, sizeof(c));
195
196	wrpll_configure_for_rate(&c, rate, *parent_rate);
197
198	return wrpll_calc_output_rate(&c, *parent_rate);
199}
200
201int sifive_prci_wrpll_set_rate(struct clk_hw *hw,
202			       unsigned long rate, unsigned long parent_rate)
203{
204	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
205	struct __prci_wrpll_data *pwd = pc->pwd;
206	struct __prci_data *pd = pc->pd;
207	int r;
208
209	r = wrpll_configure_for_rate(&pwd->c, rate, parent_rate);
210	if (r)
211		return r;
212
213	if (pwd->enable_bypass)
214		pwd->enable_bypass(pd);
215
216	__prci_wrpll_write_cfg0(pd, pwd, &pwd->c);
217
218	udelay(wrpll_calc_max_lock_us(&pwd->c));
219
220	return 0;
221}
222
223int sifive_clk_is_enabled(struct clk_hw *hw)
224{
225	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
226	struct __prci_wrpll_data *pwd = pc->pwd;
227	struct __prci_data *pd = pc->pd;
228	u32 r;
229
230	r = __prci_readl(pd, pwd->cfg1_offs);
231
232	if (r & PRCI_COREPLLCFG1_CKE_MASK)
233		return 1;
234	else
235		return 0;
236}
237
238int sifive_prci_clock_enable(struct clk_hw *hw)
239{
240	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
241	struct __prci_wrpll_data *pwd = pc->pwd;
242	struct __prci_data *pd = pc->pd;
243
244	if (sifive_clk_is_enabled(hw))
245		return 0;
246
247	__prci_wrpll_write_cfg1(pd, pwd, PRCI_COREPLLCFG1_CKE_MASK);
248
249	if (pwd->disable_bypass)
250		pwd->disable_bypass(pd);
251
252	return 0;
253}
254
255void sifive_prci_clock_disable(struct clk_hw *hw)
256{
257	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
258	struct __prci_wrpll_data *pwd = pc->pwd;
259	struct __prci_data *pd = pc->pd;
260	u32 r;
261
262	if (pwd->enable_bypass)
263		pwd->enable_bypass(pd);
264
265	r = __prci_readl(pd, pwd->cfg1_offs);
266	r &= ~PRCI_COREPLLCFG1_CKE_MASK;
267
268	__prci_wrpll_write_cfg1(pd, pwd, r);
269}
270
271/* TLCLKSEL clock integration */
272
273unsigned long sifive_prci_tlclksel_recalc_rate(struct clk_hw *hw,
274					       unsigned long parent_rate)
275{
276	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
277	struct __prci_data *pd = pc->pd;
278	u32 v;
279	u8 div;
280
281	v = __prci_readl(pd, PRCI_CLKMUXSTATUSREG_OFFSET);
282	v &= PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK;
283	div = v ? 1 : 2;
284
285	return div_u64(parent_rate, div);
286}
287
288/* HFPCLK clock integration */
289
290unsigned long sifive_prci_hfpclkplldiv_recalc_rate(struct clk_hw *hw,
291						   unsigned long parent_rate)
292{
293	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
294	struct __prci_data *pd = pc->pd;
295	u32 div = __prci_readl(pd, PRCI_HFPCLKPLLDIV_OFFSET);
296
297	return div_u64(parent_rate, div + 2);
298}
299
300/*
301 * Core clock mux control
302 */
303
304/**
305 * sifive_prci_coreclksel_use_hfclk() - switch the CORECLK mux to output HFCLK
306 * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
307 *
308 * Switch the CORECLK mux to the HFCLK input source; return once complete.
309 *
310 * Context: Any context.  Caller must prevent concurrent changes to the
311 *          PRCI_CORECLKSEL_OFFSET register.
312 */
313void sifive_prci_coreclksel_use_hfclk(struct __prci_data *pd)
314{
315	u32 r;
316
317	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
318	r |= PRCI_CORECLKSEL_CORECLKSEL_MASK;
319	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
320
321	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
322}
323
324/**
325 * sifive_prci_coreclksel_use_corepll() - switch the CORECLK mux to output
326 * COREPLL
327 * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
328 *
329 * Switch the CORECLK mux to the COREPLL output clock; return once complete.
330 *
331 * Context: Any context.  Caller must prevent concurrent changes to the
332 *          PRCI_CORECLKSEL_OFFSET register.
333 */
334void sifive_prci_coreclksel_use_corepll(struct __prci_data *pd)
335{
336	u32 r;
337
338	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
339	r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
340	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
341
342	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
343}
344
345/**
346 * sifive_prci_coreclksel_use_final_corepll() - switch the CORECLK mux to output
347 * FINAL_COREPLL
348 * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
349 *
350 * Switch the CORECLK mux to the final COREPLL output clock; return once
351 * complete.
352 *
353 * Context: Any context.  Caller must prevent concurrent changes to the
354 *          PRCI_CORECLKSEL_OFFSET register.
355 */
356void sifive_prci_coreclksel_use_final_corepll(struct __prci_data *pd)
357{
358	u32 r;
359
360	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
361	r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
362	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
363
364	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
365}
366
367/**
368 * sifive_prci_corepllsel_use_dvfscorepll() - switch the COREPLL mux to
369 * output DVFS_COREPLL
370 * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
371 *
372 * Switch the COREPLL mux to the DVFSCOREPLL output clock; return once complete.
373 *
374 * Context: Any context.  Caller must prevent concurrent changes to the
375 *          PRCI_COREPLLSEL_OFFSET register.
376 */
377void sifive_prci_corepllsel_use_dvfscorepll(struct __prci_data *pd)
378{
379	u32 r;
380
381	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
382	r |= PRCI_COREPLLSEL_COREPLLSEL_MASK;
383	__prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
384
385	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);	/* barrier */
386}
387
388/**
389 * sifive_prci_corepllsel_use_corepll() - switch the COREPLL mux to
390 * output COREPLL
391 * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
392 *
393 * Switch the COREPLL mux to the COREPLL output clock; return once complete.
394 *
395 * Context: Any context.  Caller must prevent concurrent changes to the
396 *          PRCI_COREPLLSEL_OFFSET register.
397 */
398void sifive_prci_corepllsel_use_corepll(struct __prci_data *pd)
399{
400	u32 r;
401
402	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
403	r &= ~PRCI_COREPLLSEL_COREPLLSEL_MASK;
404	__prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
405
406	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);	/* barrier */
407}
408
409/**
410 * sifive_prci_hfpclkpllsel_use_hfclk() - switch the HFPCLKPLL mux to
411 * output HFCLK
412 * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
413 *
414 * Switch the HFPCLKPLL mux to the HFCLK input source; return once complete.
415 *
416 * Context: Any context.  Caller must prevent concurrent changes to the
417 *          PRCI_HFPCLKPLLSEL_OFFSET register.
418 */
419void sifive_prci_hfpclkpllsel_use_hfclk(struct __prci_data *pd)
420{
421	u32 r;
422
423	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
424	r |= PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
425	__prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
426
427	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);	/* barrier */
428}
429
430/**
431 * sifive_prci_hfpclkpllsel_use_hfpclkpll() - switch the HFPCLKPLL mux to
432 * output HFPCLKPLL
433 * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
434 *
435 * Switch the HFPCLKPLL mux to the HFPCLKPLL output clock; return once complete.
436 *
437 * Context: Any context.  Caller must prevent concurrent changes to the
438 *          PRCI_HFPCLKPLLSEL_OFFSET register.
439 */
440void sifive_prci_hfpclkpllsel_use_hfpclkpll(struct __prci_data *pd)
441{
442	u32 r;
443
444	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
445	r &= ~PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
446	__prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
447
448	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);	/* barrier */
449}
450
451/* PCIE AUX clock APIs for enable, disable. */
452int sifive_prci_pcie_aux_clock_is_enabled(struct clk_hw *hw)
453{
454	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
455	struct __prci_data *pd = pc->pd;
456	u32 r;
457
458	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);
459
460	if (r & PRCI_PCIE_AUX_EN_MASK)
461		return 1;
462	else
463		return 0;
464}
465
466int sifive_prci_pcie_aux_clock_enable(struct clk_hw *hw)
467{
468	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
469	struct __prci_data *pd = pc->pd;
470	u32 r __maybe_unused;
471
472	if (sifive_prci_pcie_aux_clock_is_enabled(hw))
473		return 0;
474
475	__prci_writel(1, PRCI_PCIE_AUX_OFFSET, pd);
476	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);	/* barrier */
477
478	return 0;
479}
480
481void sifive_prci_pcie_aux_clock_disable(struct clk_hw *hw)
482{
483	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
484	struct __prci_data *pd = pc->pd;
485	u32 r __maybe_unused;
486
487	__prci_writel(0, PRCI_PCIE_AUX_OFFSET, pd);
488	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);	/* barrier */
489
490}
491
492/**
493 * __prci_register_clocks() - register clock controls in the PRCI
494 * @dev: Linux struct device
495 * @pd: The pointer for PRCI per-device instance data
496 * @desc: The pointer for the information of clocks of each SoCs
497 *
498 * Register the list of clock controls described in __prci_init_clocks[] with
499 * the Linux clock framework.
500 *
501 * Return: 0 upon success or a negative error code upon failure.
502 */
503static int __prci_register_clocks(struct device *dev, struct __prci_data *pd,
504				  const struct prci_clk_desc *desc)
505{
506	struct clk_init_data init = { };
507	struct __prci_clock *pic;
508	int parent_count, i, r;
509
510	parent_count = of_clk_get_parent_count(dev->of_node);
511	if (parent_count != EXPECTED_CLK_PARENT_COUNT) {
512		dev_err(dev, "expected only two parent clocks, found %d\n",
513			parent_count);
514		return -EINVAL;
515	}
516
517	/* Register PLLs */
518	for (i = 0; i < desc->num_clks; ++i) {
519		pic = &(desc->clks[i]);
520
521		init.name = pic->name;
522		init.parent_names = &pic->parent_name;
523		init.num_parents = 1;
524		init.ops = pic->ops;
525		pic->hw.init = &init;
526
527		pic->pd = pd;
528
529		if (pic->pwd)
530			__prci_wrpll_read_cfg0(pd, pic->pwd);
531
532		r = devm_clk_hw_register(dev, &pic->hw);
533		if (r) {
534			dev_warn(dev, "Failed to register clock %s: %d\n",
535				 init.name, r);
536			return r;
537		}
538
539		r = clk_hw_register_clkdev(&pic->hw, pic->name, dev_name(dev));
540		if (r) {
541			dev_warn(dev, "Failed to register clkdev for %s: %d\n",
542				 init.name, r);
543			return r;
544		}
545
546		pd->hw_clks.hws[i] = &pic->hw;
547	}
548
549	pd->hw_clks.num = i;
550
551	r = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
552					&pd->hw_clks);
553	if (r) {
554		dev_err(dev, "could not add hw_provider: %d\n", r);
555		return r;
556	}
557
558	return 0;
559}
560
561/**
562 * sifive_prci_probe() - initialize prci data and check parent count
563 * @pdev: platform device pointer for the prci
564 *
565 * Return: 0 upon success or a negative error code upon failure.
566 */
567static int sifive_prci_probe(struct platform_device *pdev)
568{
569	struct device *dev = &pdev->dev;
570	struct __prci_data *pd;
571	const struct prci_clk_desc *desc;
572	int r;
573
574	desc = of_device_get_match_data(&pdev->dev);
575
576	pd = devm_kzalloc(dev, struct_size(pd, hw_clks.hws, desc->num_clks), GFP_KERNEL);
577	if (!pd)
578		return -ENOMEM;
579
580	pd->va = devm_platform_ioremap_resource(pdev, 0);
581	if (IS_ERR(pd->va))
582		return PTR_ERR(pd->va);
583
584	pd->reset.rcdev.owner = THIS_MODULE;
585	pd->reset.rcdev.nr_resets = PRCI_RST_NR;
586	pd->reset.rcdev.ops = &reset_simple_ops;
587	pd->reset.rcdev.of_node = pdev->dev.of_node;
588	pd->reset.active_low = true;
589	pd->reset.membase = pd->va + PRCI_DEVICESRESETREG_OFFSET;
590	spin_lock_init(&pd->reset.lock);
591
592	r = devm_reset_controller_register(&pdev->dev, &pd->reset.rcdev);
593	if (r) {
594		dev_err(dev, "could not register reset controller: %d\n", r);
595		return r;
596	}
597	r = __prci_register_clocks(dev, pd, desc);
598	if (r) {
599		dev_err(dev, "could not register clocks: %d\n", r);
600		return r;
601	}
602
603	dev_dbg(dev, "SiFive PRCI probed\n");
604
605	return 0;
606}
607
608static const struct of_device_id sifive_prci_of_match[] = {
609	{.compatible = "sifive,fu540-c000-prci", .data = &prci_clk_fu540},
610	{.compatible = "sifive,fu740-c000-prci", .data = &prci_clk_fu740},
611	{}
612};
613
614static struct platform_driver sifive_prci_driver = {
615	.driver = {
616		.name = "sifive-clk-prci",
617		.of_match_table = sifive_prci_of_match,
618	},
619	.probe = sifive_prci_probe,
620};
621
622static int __init sifive_prci_init(void)
623{
624	return platform_driver_register(&sifive_prci_driver);
625}
626core_initcall(sifive_prci_init);
627