xref: /openbmc/linux/drivers/clk/ralink/clk-mt7621.c (revision 844f5ed5)
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 & 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 	/*
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 
154 static 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 
176 err_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 
192 static 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 
200 static 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 
223 err_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 
231 static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
232 {
233 	return container_of(hw, struct mt7621_clk, hw);
234 }
235 
236 static 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 
254 static 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 
289 static 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 
309 static 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 
315 static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
316 
317 static 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 
343 err_clk_unreg:
344 	while (--i >= 0) {
345 		sclk = &mt7621_clks_base[i];
346 		clk_hw_unregister(&sclk->hw);
347 	}
348 	return ret;
349 }
350 
351 static 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 
395 unreg_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 
402 free_clk_data:
403 	kfree(clk_data);
404 
405 free_clk_priv:
406 	kfree(priv);
407 }
408 CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
409 
410 struct mt7621_rst {
411 	struct reset_controller_dev rcdev;
412 	struct regmap *sysc;
413 };
414 
415 static struct mt7621_rst *to_mt7621_rst(struct reset_controller_dev *dev)
416 {
417 	return container_of(dev, struct mt7621_rst, rcdev);
418 }
419 
420 static 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 
429 static 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 
438 static 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 
450 static 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 
461 static const struct reset_control_ops reset_ops = {
462 	.reset = mt7621_reset_device,
463 	.assert = mt7621_assert_device,
464 	.deassert = mt7621_deassert_device
465 };
466 
467 static 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 
486 static 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 
525 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
526 		clk_data->hws[i] = mt7621_clk_early[i];
527 
528 	ret = mt7621_register_fixed_clocks(dev, clk_data);
529 	if (ret) {
530 		dev_err(dev, "Couldn't register fixed clocks\n");
531 		return ret;
532 	}
533 
534 	ret = mt7621_register_gates(dev, clk_data, priv);
535 	if (ret) {
536 		dev_err(dev, "Couldn't register fixed clock gates\n");
537 		goto unreg_clk_fixed;
538 	}
539 
540 	clk_data->num = count;
541 
542 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
543 	if (ret) {
544 		dev_err(dev, "Couldn't add clk hw provider\n");
545 		goto unreg_clk_gates;
546 	}
547 
548 	return 0;
549 
550 unreg_clk_gates:
551 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
552 		struct mt7621_gate *sclk = &mt7621_gates[i];
553 
554 		clk_hw_unregister(&sclk->hw);
555 	}
556 
557 unreg_clk_fixed:
558 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
559 		struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
560 
561 		clk_hw_unregister_fixed_rate(sclk->hw);
562 	}
563 
564 	return ret;
565 }
566 
567 static const struct of_device_id mt7621_clk_of_match[] = {
568 	{ .compatible = "mediatek,mt7621-sysc" },
569 	{}
570 };
571 
572 static struct platform_driver mt7621_clk_driver = {
573 	.probe = mt7621_clk_probe,
574 	.driver = {
575 		.name = "mt7621-clk",
576 		.of_match_table = mt7621_clk_of_match,
577 	},
578 };
579 
580 static int __init mt7621_clk_reset_init(void)
581 {
582 	return platform_driver_register(&mt7621_clk_driver);
583 }
584 arch_initcall(mt7621_clk_reset_init);
585