xref: /openbmc/linux/drivers/clk/ralink/clk-mt7621.c (revision c4e78957)
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 
35 struct mt7621_clk_priv {
36 	struct regmap *sysc;
37 	struct regmap *memc;
38 };
39 
40 struct mt7621_clk {
41 	struct clk_hw hw;
42 	struct mt7621_clk_priv *priv;
43 };
44 
45 struct 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 
53 struct 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 
70 static 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 
93 static inline struct mt7621_gate *to_mt7621_gate(struct clk_hw *hw)
94 {
95 	return container_of(hw, struct mt7621_gate, hw);
96 }
97 
98 static 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 
107 static 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 
115 static 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 & BIT(clk_gate->bit_idx);
125 }
126 
127 static 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 
133 static int mt7621_gate_ops_init(struct device *dev,
134 				struct mt7621_gate *sclk)
135 {
136 	struct clk_init_data init = {
137 		.flags = CLK_SET_RATE_PARENT,
138 		.num_parents = 1,
139 		.parent_names = &sclk->parent_name,
140 		.ops = &mt7621_gate_ops,
141 		.name = sclk->name,
142 	};
143 
144 	sclk->hw.init = &init;
145 	return devm_clk_hw_register(dev, &sclk->hw);
146 }
147 
148 static int mt7621_register_gates(struct device *dev,
149 				 struct clk_hw_onecell_data *clk_data,
150 				 struct mt7621_clk_priv *priv)
151 {
152 	struct clk_hw **hws = clk_data->hws;
153 	struct mt7621_gate *sclk;
154 	int ret, i;
155 
156 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
157 		sclk = &mt7621_gates[i];
158 		sclk->priv = priv;
159 		ret = mt7621_gate_ops_init(dev, sclk);
160 		if (ret) {
161 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
162 			goto err_clk_unreg;
163 		}
164 
165 		hws[sclk->idx] = &sclk->hw;
166 	}
167 
168 	return 0;
169 
170 err_clk_unreg:
171 	while (--i >= 0) {
172 		sclk = &mt7621_gates[i];
173 		clk_hw_unregister(&sclk->hw);
174 	}
175 	return ret;
176 }
177 
178 #define FIXED(_id, _name, _rate)		\
179 	{					\
180 		.idx		= _id,		\
181 		.name		= _name,	\
182 		.parent_name	= "xtal",	\
183 		.rate		= _rate		\
184 	}
185 
186 static struct mt7621_fixed_clk mt7621_fixed_clks[] = {
187 	FIXED(MT7621_CLK_50M, "50m", 50000000),
188 	FIXED(MT7621_CLK_125M, "125m", 125000000),
189 	FIXED(MT7621_CLK_150M, "150m", 150000000),
190 	FIXED(MT7621_CLK_250M, "250m", 250000000),
191 	FIXED(MT7621_CLK_270M, "270m", 270000000),
192 };
193 
194 static int mt7621_register_fixed_clocks(struct device *dev,
195 					struct clk_hw_onecell_data *clk_data)
196 {
197 	struct clk_hw **hws = clk_data->hws;
198 	struct mt7621_fixed_clk *sclk;
199 	int ret, i;
200 
201 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
202 		sclk = &mt7621_fixed_clks[i];
203 		sclk->hw = clk_hw_register_fixed_rate(dev, sclk->name,
204 						      sclk->parent_name, 0,
205 						      sclk->rate);
206 		if (IS_ERR(sclk->hw)) {
207 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
208 			ret = PTR_ERR(sclk->hw);
209 			goto err_clk_unreg;
210 		}
211 
212 		hws[sclk->idx] = sclk->hw;
213 	}
214 
215 	return 0;
216 
217 err_clk_unreg:
218 	while (--i >= 0) {
219 		sclk = &mt7621_fixed_clks[i];
220 		clk_hw_unregister_fixed_rate(sclk->hw);
221 	}
222 	return ret;
223 }
224 
225 static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
226 {
227 	return container_of(hw, struct mt7621_clk, hw);
228 }
229 
230 static unsigned long mt7621_xtal_recalc_rate(struct clk_hw *hw,
231 					     unsigned long parent_rate)
232 {
233 	struct mt7621_clk *clk = to_mt7621_clk(hw);
234 	struct regmap *sysc = clk->priv->sysc;
235 	u32 val;
236 
237 	regmap_read(sysc, SYSC_REG_SYSTEM_CONFIG0, &val);
238 	val = FIELD_GET(XTAL_MODE_SEL_MASK, val);
239 
240 	if (val <= 2)
241 		return 20000000;
242 	if (val <= 5)
243 		return 40000000;
244 
245 	return 25000000;
246 }
247 
248 static unsigned long mt7621_cpu_recalc_rate(struct clk_hw *hw,
249 					    unsigned long xtal_clk)
250 {
251 	static const u32 prediv_tbl[] = { 0, 1, 2, 2 };
252 	struct mt7621_clk *clk = to_mt7621_clk(hw);
253 	struct regmap *sysc = clk->priv->sysc;
254 	struct regmap *memc = clk->priv->memc;
255 	u32 clkcfg, clk_sel, curclk, ffiv, ffrac;
256 	u32 pll, prediv, fbdiv;
257 	unsigned long cpu_clk;
258 
259 	regmap_read(sysc, SYSC_REG_CLKCFG0, &clkcfg);
260 	clk_sel = FIELD_GET(CPU_CLK_SEL_MASK, clkcfg);
261 
262 	regmap_read(sysc, SYSC_REG_CUR_CLK_STS, &curclk);
263 	ffiv = FIELD_GET(CUR_CPU_FDIV_MASK, curclk);
264 	ffrac = FIELD_GET(CUR_CPU_FFRAC_MASK, curclk);
265 
266 	switch (clk_sel) {
267 	case 0:
268 		cpu_clk = 500000000;
269 		break;
270 	case 1:
271 		regmap_read(memc, MEMC_REG_CPU_PLL, &pll);
272 		fbdiv = FIELD_GET(CPU_PLL_FBDIV_MASK, pll);
273 		prediv = FIELD_GET(CPU_PLL_PREDIV_MASK, pll);
274 		cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
275 		break;
276 	default:
277 		cpu_clk = xtal_clk;
278 	}
279 
280 	return cpu_clk / ffiv * ffrac;
281 }
282 
283 static unsigned long mt7621_bus_recalc_rate(struct clk_hw *hw,
284 					    unsigned long parent_rate)
285 {
286 	return parent_rate / 4;
287 }
288 
289 #define CLK_BASE(_name, _parent, _recalc) {				\
290 	.init = &(struct clk_init_data) {				\
291 		.name = _name,						\
292 		.ops = &(const struct clk_ops) {			\
293 			.recalc_rate = _recalc,				\
294 		},							\
295 		.parent_data = &(const struct clk_parent_data) {	\
296 			.name = _parent,				\
297 			.fw_name = _parent				\
298 		},							\
299 		.num_parents = _parent ? 1 : 0				\
300 	},								\
301 }
302 
303 static struct mt7621_clk mt7621_clks_base[] = {
304 	{ CLK_BASE("xtal", NULL, mt7621_xtal_recalc_rate) },
305 	{ CLK_BASE("cpu", "xtal", mt7621_cpu_recalc_rate) },
306 	{ CLK_BASE("bus", "cpu", mt7621_bus_recalc_rate) },
307 };
308 
309 static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
310 
311 static int mt7621_register_early_clocks(struct device_node *np,
312 					struct clk_hw_onecell_data *clk_data,
313 					struct mt7621_clk_priv *priv)
314 {
315 	struct clk_hw **hws = clk_data->hws;
316 	struct mt7621_clk *sclk;
317 	int ret, i, j;
318 
319 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
320 		sclk = &mt7621_clks_base[i];
321 		sclk->priv = priv;
322 		ret = of_clk_hw_register(np, &sclk->hw);
323 		if (ret) {
324 			pr_err("Couldn't register top clock %i\n", i);
325 			goto err_clk_unreg;
326 		}
327 
328 		hws[i] = &sclk->hw;
329 		mt7621_clk_early[i] = &sclk->hw;
330 	}
331 
332 	for (j = i; j < MT7621_CLK_MAX; j++)
333 		mt7621_clk_early[j] = ERR_PTR(-EPROBE_DEFER);
334 
335 	return 0;
336 
337 err_clk_unreg:
338 	while (--i >= 0) {
339 		sclk = &mt7621_clks_base[i];
340 		clk_hw_unregister(&sclk->hw);
341 	}
342 	return ret;
343 }
344 
345 static void __init mt7621_clk_init(struct device_node *node)
346 {
347 	struct mt7621_clk_priv *priv;
348 	struct clk_hw_onecell_data *clk_data;
349 	int ret, i, count;
350 
351 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
352 	if (!priv)
353 		return;
354 
355 	priv->sysc = syscon_node_to_regmap(node);
356 	if (IS_ERR(priv->sysc)) {
357 		pr_err("Could not get sysc syscon regmap\n");
358 		goto free_clk_priv;
359 	}
360 
361 	priv->memc = syscon_regmap_lookup_by_phandle(node, "ralink,memctl");
362 	if (IS_ERR(priv->memc)) {
363 		pr_err("Could not get memc syscon regmap\n");
364 		goto free_clk_priv;
365 	}
366 
367 	count = ARRAY_SIZE(mt7621_clks_base) +
368 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
369 	clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
370 	if (!clk_data)
371 		goto free_clk_priv;
372 
373 	ret = mt7621_register_early_clocks(node, clk_data, priv);
374 	if (ret) {
375 		pr_err("Couldn't register top clocks\n");
376 		goto free_clk_data;
377 	}
378 
379 	clk_data->num = count;
380 
381 	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
382 	if (ret) {
383 		pr_err("Couldn't add clk hw provider\n");
384 		goto unreg_clk_top;
385 	}
386 
387 	return;
388 
389 unreg_clk_top:
390 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
391 		struct mt7621_clk *sclk = &mt7621_clks_base[i];
392 
393 		clk_hw_unregister(&sclk->hw);
394 	}
395 
396 free_clk_data:
397 	kfree(clk_data);
398 
399 free_clk_priv:
400 	kfree(priv);
401 }
402 CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
403 
404 struct mt7621_rst {
405 	struct reset_controller_dev rcdev;
406 	struct regmap *sysc;
407 };
408 
409 static struct mt7621_rst *to_mt7621_rst(struct reset_controller_dev *dev)
410 {
411 	return container_of(dev, struct mt7621_rst, rcdev);
412 }
413 
414 static int mt7621_assert_device(struct reset_controller_dev *rcdev,
415 				unsigned long id)
416 {
417 	struct mt7621_rst *data = to_mt7621_rst(rcdev);
418 	struct regmap *sysc = data->sysc;
419 
420 	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), BIT(id));
421 }
422 
423 static int mt7621_deassert_device(struct reset_controller_dev *rcdev,
424 				  unsigned long id)
425 {
426 	struct mt7621_rst *data = to_mt7621_rst(rcdev);
427 	struct regmap *sysc = data->sysc;
428 
429 	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), 0);
430 }
431 
432 static int mt7621_reset_device(struct reset_controller_dev *rcdev,
433 			       unsigned long id)
434 {
435 	int ret;
436 
437 	ret = mt7621_assert_device(rcdev, id);
438 	if (ret < 0)
439 		return ret;
440 
441 	return mt7621_deassert_device(rcdev, id);
442 }
443 
444 static int mt7621_rst_xlate(struct reset_controller_dev *rcdev,
445 			    const struct of_phandle_args *reset_spec)
446 {
447 	unsigned long id = reset_spec->args[0];
448 
449 	if (id == MT7621_RST_SYS || id >= rcdev->nr_resets)
450 		return -EINVAL;
451 
452 	return id;
453 }
454 
455 static const struct reset_control_ops reset_ops = {
456 	.reset = mt7621_reset_device,
457 	.assert = mt7621_assert_device,
458 	.deassert = mt7621_deassert_device
459 };
460 
461 static int mt7621_reset_init(struct device *dev, struct regmap *sysc)
462 {
463 	struct mt7621_rst *rst_data;
464 
465 	rst_data = devm_kzalloc(dev, sizeof(*rst_data), GFP_KERNEL);
466 	if (!rst_data)
467 		return -ENOMEM;
468 
469 	rst_data->sysc = sysc;
470 	rst_data->rcdev.ops = &reset_ops;
471 	rst_data->rcdev.owner = THIS_MODULE;
472 	rst_data->rcdev.nr_resets = 32;
473 	rst_data->rcdev.of_reset_n_cells = 1;
474 	rst_data->rcdev.of_xlate = mt7621_rst_xlate;
475 	rst_data->rcdev.of_node = dev_of_node(dev);
476 
477 	return devm_reset_controller_register(dev, &rst_data->rcdev);
478 }
479 
480 static int mt7621_clk_probe(struct platform_device *pdev)
481 {
482 	struct device_node *np = pdev->dev.of_node;
483 	struct clk_hw_onecell_data *clk_data;
484 	struct device *dev = &pdev->dev;
485 	struct mt7621_clk_priv *priv;
486 	int ret, i, count;
487 
488 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
489 	if (!priv)
490 		return -ENOMEM;
491 
492 	priv->sysc = syscon_node_to_regmap(np);
493 	if (IS_ERR(priv->sysc)) {
494 		ret = PTR_ERR(priv->sysc);
495 		dev_err(dev, "Could not get sysc syscon regmap\n");
496 		return ret;
497 	}
498 
499 	priv->memc = syscon_regmap_lookup_by_phandle(np, "ralink,memctl");
500 	if (IS_ERR(priv->memc)) {
501 		ret = PTR_ERR(priv->memc);
502 		dev_err(dev, "Could not get memc syscon regmap\n");
503 		return ret;
504 	}
505 
506 	ret = mt7621_reset_init(dev, priv->sysc);
507 	if (ret) {
508 		dev_err(dev, "Could not init reset controller\n");
509 		return ret;
510 	}
511 
512 	count = ARRAY_SIZE(mt7621_clks_base) +
513 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
514 	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
515 				GFP_KERNEL);
516 	if (!clk_data)
517 		return -ENOMEM;
518 
519 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
520 		clk_data->hws[i] = mt7621_clk_early[i];
521 
522 	ret = mt7621_register_fixed_clocks(dev, clk_data);
523 	if (ret) {
524 		dev_err(dev, "Couldn't register fixed clocks\n");
525 		return ret;
526 	}
527 
528 	ret = mt7621_register_gates(dev, clk_data, priv);
529 	if (ret) {
530 		dev_err(dev, "Couldn't register fixed clock gates\n");
531 		goto unreg_clk_fixed;
532 	}
533 
534 	clk_data->num = count;
535 
536 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
537 	if (ret) {
538 		dev_err(dev, "Couldn't add clk hw provider\n");
539 		goto unreg_clk_gates;
540 	}
541 
542 	return 0;
543 
544 unreg_clk_gates:
545 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
546 		struct mt7621_gate *sclk = &mt7621_gates[i];
547 
548 		clk_hw_unregister(&sclk->hw);
549 	}
550 
551 unreg_clk_fixed:
552 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
553 		struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
554 
555 		clk_hw_unregister_fixed_rate(sclk->hw);
556 	}
557 
558 	return ret;
559 }
560 
561 static const struct of_device_id mt7621_clk_of_match[] = {
562 	{ .compatible = "mediatek,mt7621-sysc" },
563 	{}
564 };
565 
566 static struct platform_driver mt7621_clk_driver = {
567 	.probe = mt7621_clk_probe,
568 	.driver = {
569 		.name = "mt7621-clk",
570 		.of_match_table = mt7621_clk_of_match,
571 	},
572 };
573 
574 static int __init mt7621_clk_reset_init(void)
575 {
576 	return platform_driver_register(&mt7621_clk_driver);
577 }
578 arch_initcall(mt7621_clk_reset_init);
579