1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Mediatek MT7621 Clock Driver
4 * Author: Sergio Paracuellos <sergio.paracuellos@gmail.com>
5 */
6
7#include <linux/bitfield.h>
8#include <linux/bitops.h>
9#include <linux/clk-provider.h>
10#include <linux/clk.h>
11#include <linux/mfd/syscon.h>
12#include <linux/platform_device.h>
13#include <linux/regmap.h>
14#include <linux/reset-controller.h>
15#include <linux/slab.h>
16#include <dt-bindings/clock/mt7621-clk.h>
17#include <dt-bindings/reset/mt7621-reset.h>
18
19/* Configuration registers */
20#define SYSC_REG_SYSTEM_CONFIG0         0x10
21#define SYSC_REG_SYSTEM_CONFIG1         0x14
22#define SYSC_REG_CLKCFG0		0x2c
23#define SYSC_REG_CLKCFG1		0x30
24#define SYSC_REG_RESET_CTRL		0x34
25#define SYSC_REG_CUR_CLK_STS		0x44
26#define MEMC_REG_CPU_PLL		0x648
27
28#define XTAL_MODE_SEL_MASK		GENMASK(8, 6)
29#define CPU_CLK_SEL_MASK		GENMASK(31, 30)
30#define CUR_CPU_FDIV_MASK		GENMASK(12, 8)
31#define CUR_CPU_FFRAC_MASK		GENMASK(4, 0)
32#define CPU_PLL_PREDIV_MASK		GENMASK(13, 12)
33#define CPU_PLL_FBDIV_MASK		GENMASK(10, 4)
34
35struct mt7621_clk_priv {
36	struct regmap *sysc;
37	struct regmap *memc;
38};
39
40struct mt7621_clk {
41	struct clk_hw hw;
42	struct mt7621_clk_priv *priv;
43};
44
45struct mt7621_fixed_clk {
46	u8 idx;
47	const char *name;
48	const char *parent_name;
49	unsigned long rate;
50	struct clk_hw *hw;
51};
52
53struct mt7621_gate {
54	u8 idx;
55	const char *name;
56	const char *parent_name;
57	struct mt7621_clk_priv *priv;
58	u32 bit_idx;
59	struct clk_hw hw;
60};
61
62#define GATE(_id, _name, _pname, _shift)	\
63	{					\
64		.idx		= _id,		\
65		.name		= _name,	\
66		.parent_name	= _pname,	\
67		.bit_idx	= _shift	\
68	}
69
70static struct mt7621_gate mt7621_gates[] = {
71	GATE(MT7621_CLK_HSDMA, "hsdma", "150m", BIT(5)),
72	GATE(MT7621_CLK_FE, "fe", "250m", BIT(6)),
73	GATE(MT7621_CLK_SP_DIVTX, "sp_divtx", "270m", BIT(7)),
74	GATE(MT7621_CLK_TIMER, "timer", "50m", BIT(8)),
75	GATE(MT7621_CLK_PCM, "pcm", "270m", BIT(11)),
76	GATE(MT7621_CLK_PIO, "pio", "50m", BIT(13)),
77	GATE(MT7621_CLK_GDMA, "gdma", "bus", BIT(14)),
78	GATE(MT7621_CLK_NAND, "nand", "125m", BIT(15)),
79	GATE(MT7621_CLK_I2C, "i2c", "50m", BIT(16)),
80	GATE(MT7621_CLK_I2S, "i2s", "270m", BIT(17)),
81	GATE(MT7621_CLK_SPI, "spi", "bus", BIT(18)),
82	GATE(MT7621_CLK_UART1, "uart1", "50m", BIT(19)),
83	GATE(MT7621_CLK_UART2, "uart2", "50m", BIT(20)),
84	GATE(MT7621_CLK_UART3, "uart3", "50m", BIT(21)),
85	GATE(MT7621_CLK_ETH, "eth", "50m", BIT(23)),
86	GATE(MT7621_CLK_PCIE0, "pcie0", "125m", BIT(24)),
87	GATE(MT7621_CLK_PCIE1, "pcie1", "125m", BIT(25)),
88	GATE(MT7621_CLK_PCIE2, "pcie2", "125m", BIT(26)),
89	GATE(MT7621_CLK_CRYPTO, "crypto", "250m", BIT(29)),
90	GATE(MT7621_CLK_SHXC, "shxc", "50m", BIT(30))
91};
92
93static inline struct mt7621_gate *to_mt7621_gate(struct clk_hw *hw)
94{
95	return container_of(hw, struct mt7621_gate, hw);
96}
97
98static int mt7621_gate_enable(struct clk_hw *hw)
99{
100	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
101	struct regmap *sysc = clk_gate->priv->sysc;
102
103	return regmap_update_bits(sysc, SYSC_REG_CLKCFG1,
104				  clk_gate->bit_idx, clk_gate->bit_idx);
105}
106
107static void mt7621_gate_disable(struct clk_hw *hw)
108{
109	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
110	struct regmap *sysc = clk_gate->priv->sysc;
111
112	regmap_update_bits(sysc, SYSC_REG_CLKCFG1, clk_gate->bit_idx, 0);
113}
114
115static int mt7621_gate_is_enabled(struct clk_hw *hw)
116{
117	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
118	struct regmap *sysc = clk_gate->priv->sysc;
119	u32 val;
120
121	if (regmap_read(sysc, SYSC_REG_CLKCFG1, &val))
122		return 0;
123
124	return val & clk_gate->bit_idx;
125}
126
127static const struct clk_ops mt7621_gate_ops = {
128	.enable = mt7621_gate_enable,
129	.disable = mt7621_gate_disable,
130	.is_enabled = mt7621_gate_is_enabled,
131};
132
133static int mt7621_gate_ops_init(struct device *dev,
134				struct mt7621_gate *sclk)
135{
136	/*
137	 * There are drivers for this SoC that are older
138	 * than clock driver and are not prepared for the clock.
139	 * We don't want the kernel to disable anything so we
140	 * add CLK_IS_CRITICAL flag here.
141	 */
142	struct clk_init_data init = {
143		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
144		.num_parents = 1,
145		.parent_names = &sclk->parent_name,
146		.ops = &mt7621_gate_ops,
147		.name = sclk->name,
148	};
149
150	sclk->hw.init = &init;
151	return devm_clk_hw_register(dev, &sclk->hw);
152}
153
154static int mt7621_register_gates(struct device *dev,
155				 struct clk_hw_onecell_data *clk_data,
156				 struct mt7621_clk_priv *priv)
157{
158	struct clk_hw **hws = clk_data->hws;
159	struct mt7621_gate *sclk;
160	int ret, i;
161
162	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
163		sclk = &mt7621_gates[i];
164		sclk->priv = priv;
165		ret = mt7621_gate_ops_init(dev, sclk);
166		if (ret) {
167			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
168			goto err_clk_unreg;
169		}
170
171		hws[sclk->idx] = &sclk->hw;
172	}
173
174	return 0;
175
176err_clk_unreg:
177	while (--i >= 0) {
178		sclk = &mt7621_gates[i];
179		clk_hw_unregister(&sclk->hw);
180	}
181	return ret;
182}
183
184#define FIXED(_id, _name, _rate)		\
185	{					\
186		.idx		= _id,		\
187		.name		= _name,	\
188		.parent_name	= "xtal",	\
189		.rate		= _rate		\
190	}
191
192static struct mt7621_fixed_clk mt7621_fixed_clks[] = {
193	FIXED(MT7621_CLK_50M, "50m", 50000000),
194	FIXED(MT7621_CLK_125M, "125m", 125000000),
195	FIXED(MT7621_CLK_150M, "150m", 150000000),
196	FIXED(MT7621_CLK_250M, "250m", 250000000),
197	FIXED(MT7621_CLK_270M, "270m", 270000000),
198};
199
200static int mt7621_register_fixed_clocks(struct device *dev,
201					struct clk_hw_onecell_data *clk_data)
202{
203	struct clk_hw **hws = clk_data->hws;
204	struct mt7621_fixed_clk *sclk;
205	int ret, i;
206
207	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
208		sclk = &mt7621_fixed_clks[i];
209		sclk->hw = clk_hw_register_fixed_rate(dev, sclk->name,
210						      sclk->parent_name, 0,
211						      sclk->rate);
212		if (IS_ERR(sclk->hw)) {
213			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
214			ret = PTR_ERR(sclk->hw);
215			goto err_clk_unreg;
216		}
217
218		hws[sclk->idx] = sclk->hw;
219	}
220
221	return 0;
222
223err_clk_unreg:
224	while (--i >= 0) {
225		sclk = &mt7621_fixed_clks[i];
226		clk_hw_unregister_fixed_rate(sclk->hw);
227	}
228	return ret;
229}
230
231static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
232{
233	return container_of(hw, struct mt7621_clk, hw);
234}
235
236static unsigned long mt7621_xtal_recalc_rate(struct clk_hw *hw,
237					     unsigned long parent_rate)
238{
239	struct mt7621_clk *clk = to_mt7621_clk(hw);
240	struct regmap *sysc = clk->priv->sysc;
241	u32 val;
242
243	regmap_read(sysc, SYSC_REG_SYSTEM_CONFIG0, &val);
244	val = FIELD_GET(XTAL_MODE_SEL_MASK, val);
245
246	if (val <= 2)
247		return 20000000;
248	if (val <= 5)
249		return 40000000;
250
251	return 25000000;
252}
253
254static unsigned long mt7621_cpu_recalc_rate(struct clk_hw *hw,
255					    unsigned long xtal_clk)
256{
257	static const u32 prediv_tbl[] = { 0, 1, 2, 2 };
258	struct mt7621_clk *clk = to_mt7621_clk(hw);
259	struct regmap *sysc = clk->priv->sysc;
260	struct regmap *memc = clk->priv->memc;
261	u32 clkcfg, clk_sel, curclk, ffiv, ffrac;
262	u32 pll, prediv, fbdiv;
263	unsigned long cpu_clk;
264
265	regmap_read(sysc, SYSC_REG_CLKCFG0, &clkcfg);
266	clk_sel = FIELD_GET(CPU_CLK_SEL_MASK, clkcfg);
267
268	regmap_read(sysc, SYSC_REG_CUR_CLK_STS, &curclk);
269	ffiv = FIELD_GET(CUR_CPU_FDIV_MASK, curclk);
270	ffrac = FIELD_GET(CUR_CPU_FFRAC_MASK, curclk);
271
272	switch (clk_sel) {
273	case 0:
274		cpu_clk = 500000000;
275		break;
276	case 1:
277		regmap_read(memc, MEMC_REG_CPU_PLL, &pll);
278		fbdiv = FIELD_GET(CPU_PLL_FBDIV_MASK, pll);
279		prediv = FIELD_GET(CPU_PLL_PREDIV_MASK, pll);
280		cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
281		break;
282	default:
283		cpu_clk = xtal_clk;
284	}
285
286	return cpu_clk / ffiv * ffrac;
287}
288
289static unsigned long mt7621_bus_recalc_rate(struct clk_hw *hw,
290					    unsigned long parent_rate)
291{
292	return parent_rate / 4;
293}
294
295#define CLK_BASE(_name, _parent, _recalc) {				\
296	.init = &(struct clk_init_data) {				\
297		.name = _name,						\
298		.ops = &(const struct clk_ops) {			\
299			.recalc_rate = _recalc,				\
300		},							\
301		.parent_data = &(const struct clk_parent_data) {	\
302			.name = _parent,				\
303			.fw_name = _parent				\
304		},							\
305		.num_parents = _parent ? 1 : 0				\
306	},								\
307}
308
309static struct mt7621_clk mt7621_clks_base[] = {
310	{ CLK_BASE("xtal", NULL, mt7621_xtal_recalc_rate) },
311	{ CLK_BASE("cpu", "xtal", mt7621_cpu_recalc_rate) },
312	{ CLK_BASE("bus", "cpu", mt7621_bus_recalc_rate) },
313};
314
315static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
316
317static int mt7621_register_early_clocks(struct device_node *np,
318					struct clk_hw_onecell_data *clk_data,
319					struct mt7621_clk_priv *priv)
320{
321	struct clk_hw **hws = clk_data->hws;
322	struct mt7621_clk *sclk;
323	int ret, i, j;
324
325	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
326		sclk = &mt7621_clks_base[i];
327		sclk->priv = priv;
328		ret = of_clk_hw_register(np, &sclk->hw);
329		if (ret) {
330			pr_err("Couldn't register top clock %i\n", i);
331			goto err_clk_unreg;
332		}
333
334		hws[i] = &sclk->hw;
335		mt7621_clk_early[i] = &sclk->hw;
336	}
337
338	for (j = i; j < MT7621_CLK_MAX; j++)
339		mt7621_clk_early[j] = ERR_PTR(-EPROBE_DEFER);
340
341	return 0;
342
343err_clk_unreg:
344	while (--i >= 0) {
345		sclk = &mt7621_clks_base[i];
346		clk_hw_unregister(&sclk->hw);
347	}
348	return ret;
349}
350
351static void __init mt7621_clk_init(struct device_node *node)
352{
353	struct mt7621_clk_priv *priv;
354	struct clk_hw_onecell_data *clk_data;
355	int ret, i, count;
356
357	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
358	if (!priv)
359		return;
360
361	priv->sysc = syscon_node_to_regmap(node);
362	if (IS_ERR(priv->sysc)) {
363		pr_err("Could not get sysc syscon regmap\n");
364		goto free_clk_priv;
365	}
366
367	priv->memc = syscon_regmap_lookup_by_phandle(node, "ralink,memctl");
368	if (IS_ERR(priv->memc)) {
369		pr_err("Could not get memc syscon regmap\n");
370		goto free_clk_priv;
371	}
372
373	count = ARRAY_SIZE(mt7621_clks_base) +
374		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
375	clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
376	if (!clk_data)
377		goto free_clk_priv;
378
379	ret = mt7621_register_early_clocks(node, clk_data, priv);
380	if (ret) {
381		pr_err("Couldn't register top clocks\n");
382		goto free_clk_data;
383	}
384
385	clk_data->num = count;
386
387	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
388	if (ret) {
389		pr_err("Couldn't add clk hw provider\n");
390		goto unreg_clk_top;
391	}
392
393	return;
394
395unreg_clk_top:
396	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
397		struct mt7621_clk *sclk = &mt7621_clks_base[i];
398
399		clk_hw_unregister(&sclk->hw);
400	}
401
402free_clk_data:
403	kfree(clk_data);
404
405free_clk_priv:
406	kfree(priv);
407}
408CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
409
410struct mt7621_rst {
411	struct reset_controller_dev rcdev;
412	struct regmap *sysc;
413};
414
415static struct mt7621_rst *to_mt7621_rst(struct reset_controller_dev *dev)
416{
417	return container_of(dev, struct mt7621_rst, rcdev);
418}
419
420static int mt7621_assert_device(struct reset_controller_dev *rcdev,
421				unsigned long id)
422{
423	struct mt7621_rst *data = to_mt7621_rst(rcdev);
424	struct regmap *sysc = data->sysc;
425
426	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), BIT(id));
427}
428
429static int mt7621_deassert_device(struct reset_controller_dev *rcdev,
430				  unsigned long id)
431{
432	struct mt7621_rst *data = to_mt7621_rst(rcdev);
433	struct regmap *sysc = data->sysc;
434
435	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), 0);
436}
437
438static int mt7621_reset_device(struct reset_controller_dev *rcdev,
439			       unsigned long id)
440{
441	int ret;
442
443	ret = mt7621_assert_device(rcdev, id);
444	if (ret < 0)
445		return ret;
446
447	return mt7621_deassert_device(rcdev, id);
448}
449
450static int mt7621_rst_xlate(struct reset_controller_dev *rcdev,
451			    const struct of_phandle_args *reset_spec)
452{
453	unsigned long id = reset_spec->args[0];
454
455	if (id == MT7621_RST_SYS || id >= rcdev->nr_resets)
456		return -EINVAL;
457
458	return id;
459}
460
461static const struct reset_control_ops reset_ops = {
462	.reset = mt7621_reset_device,
463	.assert = mt7621_assert_device,
464	.deassert = mt7621_deassert_device
465};
466
467static int mt7621_reset_init(struct device *dev, struct regmap *sysc)
468{
469	struct mt7621_rst *rst_data;
470
471	rst_data = devm_kzalloc(dev, sizeof(*rst_data), GFP_KERNEL);
472	if (!rst_data)
473		return -ENOMEM;
474
475	rst_data->sysc = sysc;
476	rst_data->rcdev.ops = &reset_ops;
477	rst_data->rcdev.owner = THIS_MODULE;
478	rst_data->rcdev.nr_resets = 32;
479	rst_data->rcdev.of_reset_n_cells = 1;
480	rst_data->rcdev.of_xlate = mt7621_rst_xlate;
481	rst_data->rcdev.of_node = dev_of_node(dev);
482
483	return devm_reset_controller_register(dev, &rst_data->rcdev);
484}
485
486static int mt7621_clk_probe(struct platform_device *pdev)
487{
488	struct device_node *np = pdev->dev.of_node;
489	struct clk_hw_onecell_data *clk_data;
490	struct device *dev = &pdev->dev;
491	struct mt7621_clk_priv *priv;
492	int ret, i, count;
493
494	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
495	if (!priv)
496		return -ENOMEM;
497
498	priv->sysc = syscon_node_to_regmap(np);
499	if (IS_ERR(priv->sysc)) {
500		ret = PTR_ERR(priv->sysc);
501		dev_err(dev, "Could not get sysc syscon regmap\n");
502		return ret;
503	}
504
505	priv->memc = syscon_regmap_lookup_by_phandle(np, "ralink,memctl");
506	if (IS_ERR(priv->memc)) {
507		ret = PTR_ERR(priv->memc);
508		dev_err(dev, "Could not get memc syscon regmap\n");
509		return ret;
510	}
511
512	ret = mt7621_reset_init(dev, priv->sysc);
513	if (ret) {
514		dev_err(dev, "Could not init reset controller\n");
515		return ret;
516	}
517
518	count = ARRAY_SIZE(mt7621_clks_base) +
519		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
520	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
521				GFP_KERNEL);
522	if (!clk_data)
523		return -ENOMEM;
524	clk_data->num = count;
525
526	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
527		clk_data->hws[i] = mt7621_clk_early[i];
528
529	ret = mt7621_register_fixed_clocks(dev, clk_data);
530	if (ret) {
531		dev_err(dev, "Couldn't register fixed clocks\n");
532		return ret;
533	}
534
535	ret = mt7621_register_gates(dev, clk_data, priv);
536	if (ret) {
537		dev_err(dev, "Couldn't register fixed clock gates\n");
538		goto unreg_clk_fixed;
539	}
540
541	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
542	if (ret) {
543		dev_err(dev, "Couldn't add clk hw provider\n");
544		goto unreg_clk_gates;
545	}
546
547	return 0;
548
549unreg_clk_gates:
550	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
551		struct mt7621_gate *sclk = &mt7621_gates[i];
552
553		clk_hw_unregister(&sclk->hw);
554	}
555
556unreg_clk_fixed:
557	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
558		struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
559
560		clk_hw_unregister_fixed_rate(sclk->hw);
561	}
562
563	return ret;
564}
565
566static const struct of_device_id mt7621_clk_of_match[] = {
567	{ .compatible = "mediatek,mt7621-sysc" },
568	{}
569};
570
571static struct platform_driver mt7621_clk_driver = {
572	.probe = mt7621_clk_probe,
573	.driver = {
574		.name = "mt7621-clk",
575		.of_match_table = mt7621_clk_of_match,
576	},
577};
578
579static int __init mt7621_clk_reset_init(void)
580{
581	return platform_driver_register(&mt7621_clk_driver);
582}
583arch_initcall(mt7621_clk_reset_init);
584