xref: /openbmc/linux/drivers/clk/ralink/clk-mt7621.c (revision babbdf5b)
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/slab.h>
15 #include <dt-bindings/clock/mt7621-clk.h>
16 
17 /* Configuration registers */
18 #define SYSC_REG_SYSTEM_CONFIG0         0x10
19 #define SYSC_REG_SYSTEM_CONFIG1         0x14
20 #define SYSC_REG_CLKCFG0		0x2c
21 #define SYSC_REG_CLKCFG1		0x30
22 #define SYSC_REG_CUR_CLK_STS		0x44
23 #define MEMC_REG_CPU_PLL		0x648
24 
25 #define XTAL_MODE_SEL_MASK		GENMASK(8, 6)
26 #define CPU_CLK_SEL_MASK		GENMASK(31, 30)
27 #define CUR_CPU_FDIV_MASK		GENMASK(12, 8)
28 #define CUR_CPU_FFRAC_MASK		GENMASK(4, 0)
29 #define CPU_PLL_PREDIV_MASK		GENMASK(13, 12)
30 #define CPU_PLL_FBDIV_MASK		GENMASK(10, 4)
31 
32 struct mt7621_clk_priv {
33 	struct regmap *sysc;
34 	struct regmap *memc;
35 };
36 
37 struct mt7621_clk {
38 	struct clk_hw hw;
39 	struct mt7621_clk_priv *priv;
40 };
41 
42 struct mt7621_fixed_clk {
43 	u8 idx;
44 	const char *name;
45 	const char *parent_name;
46 	unsigned long rate;
47 	struct clk_hw *hw;
48 };
49 
50 struct mt7621_gate {
51 	u8 idx;
52 	const char *name;
53 	const char *parent_name;
54 	struct mt7621_clk_priv *priv;
55 	u32 bit_idx;
56 	struct clk_hw hw;
57 };
58 
59 #define GATE(_id, _name, _pname, _shift)	\
60 	{					\
61 		.idx		= _id,		\
62 		.name		= _name,	\
63 		.parent_name	= _pname,	\
64 		.bit_idx	= _shift	\
65 	}
66 
67 static struct mt7621_gate mt7621_gates[] = {
68 	GATE(MT7621_CLK_HSDMA, "hsdma", "150m", BIT(5)),
69 	GATE(MT7621_CLK_FE, "fe", "250m", BIT(6)),
70 	GATE(MT7621_CLK_SP_DIVTX, "sp_divtx", "270m", BIT(7)),
71 	GATE(MT7621_CLK_TIMER, "timer", "50m", BIT(8)),
72 	GATE(MT7621_CLK_PCM, "pcm", "270m", BIT(11)),
73 	GATE(MT7621_CLK_PIO, "pio", "50m", BIT(13)),
74 	GATE(MT7621_CLK_GDMA, "gdma", "bus", BIT(14)),
75 	GATE(MT7621_CLK_NAND, "nand", "125m", BIT(15)),
76 	GATE(MT7621_CLK_I2C, "i2c", "50m", BIT(16)),
77 	GATE(MT7621_CLK_I2S, "i2s", "270m", BIT(17)),
78 	GATE(MT7621_CLK_SPI, "spi", "bus", BIT(18)),
79 	GATE(MT7621_CLK_UART1, "uart1", "50m", BIT(19)),
80 	GATE(MT7621_CLK_UART2, "uart2", "50m", BIT(20)),
81 	GATE(MT7621_CLK_UART3, "uart3", "50m", BIT(21)),
82 	GATE(MT7621_CLK_ETH, "eth", "50m", BIT(23)),
83 	GATE(MT7621_CLK_PCIE0, "pcie0", "125m", BIT(24)),
84 	GATE(MT7621_CLK_PCIE1, "pcie1", "125m", BIT(25)),
85 	GATE(MT7621_CLK_PCIE2, "pcie2", "125m", BIT(26)),
86 	GATE(MT7621_CLK_CRYPTO, "crypto", "250m", BIT(29)),
87 	GATE(MT7621_CLK_SHXC, "shxc", "50m", BIT(30))
88 };
89 
90 static inline struct mt7621_gate *to_mt7621_gate(struct clk_hw *hw)
91 {
92 	return container_of(hw, struct mt7621_gate, hw);
93 }
94 
95 static int mt7621_gate_enable(struct clk_hw *hw)
96 {
97 	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
98 	struct regmap *sysc = clk_gate->priv->sysc;
99 
100 	return regmap_update_bits(sysc, SYSC_REG_CLKCFG1,
101 				  clk_gate->bit_idx, clk_gate->bit_idx);
102 }
103 
104 static void mt7621_gate_disable(struct clk_hw *hw)
105 {
106 	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
107 	struct regmap *sysc = clk_gate->priv->sysc;
108 
109 	regmap_update_bits(sysc, SYSC_REG_CLKCFG1, clk_gate->bit_idx, 0);
110 }
111 
112 static int mt7621_gate_is_enabled(struct clk_hw *hw)
113 {
114 	struct mt7621_gate *clk_gate = to_mt7621_gate(hw);
115 	struct regmap *sysc = clk_gate->priv->sysc;
116 	u32 val;
117 
118 	if (regmap_read(sysc, SYSC_REG_CLKCFG1, &val))
119 		return 0;
120 
121 	return val & BIT(clk_gate->bit_idx);
122 }
123 
124 static const struct clk_ops mt7621_gate_ops = {
125 	.enable = mt7621_gate_enable,
126 	.disable = mt7621_gate_disable,
127 	.is_enabled = mt7621_gate_is_enabled,
128 };
129 
130 static int mt7621_gate_ops_init(struct device *dev,
131 				struct mt7621_gate *sclk)
132 {
133 	struct clk_init_data init = {
134 		/*
135 		 * Until now no clock driver existed so
136 		 * these SoC drivers are not prepared
137 		 * yet for the clock. We don't want kernel to
138 		 * disable anything so we add CLK_IS_CRITICAL
139 		 * flag here.
140 		 */
141 		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
142 		.num_parents = 1,
143 		.parent_names = &sclk->parent_name,
144 		.ops = &mt7621_gate_ops,
145 		.name = sclk->name,
146 	};
147 
148 	sclk->hw.init = &init;
149 	return devm_clk_hw_register(dev, &sclk->hw);
150 }
151 
152 static int mt7621_register_gates(struct device *dev,
153 				 struct clk_hw_onecell_data *clk_data,
154 				 struct mt7621_clk_priv *priv)
155 {
156 	struct clk_hw **hws = clk_data->hws;
157 	struct mt7621_gate *sclk;
158 	int ret, i;
159 
160 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
161 		sclk = &mt7621_gates[i];
162 		sclk->priv = priv;
163 		ret = mt7621_gate_ops_init(dev, sclk);
164 		if (ret) {
165 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
166 			goto err_clk_unreg;
167 		}
168 
169 		hws[sclk->idx] = &sclk->hw;
170 	}
171 
172 	return 0;
173 
174 err_clk_unreg:
175 	while (--i >= 0) {
176 		sclk = &mt7621_gates[i];
177 		clk_hw_unregister(&sclk->hw);
178 	}
179 	return ret;
180 }
181 
182 #define FIXED(_id, _name, _rate)		\
183 	{					\
184 		.idx		= _id,		\
185 		.name		= _name,	\
186 		.parent_name	= "xtal",	\
187 		.rate		= _rate		\
188 	}
189 
190 static struct mt7621_fixed_clk mt7621_fixed_clks[] = {
191 	FIXED(MT7621_CLK_50M, "50m", 50000000),
192 	FIXED(MT7621_CLK_125M, "125m", 125000000),
193 	FIXED(MT7621_CLK_150M, "150m", 150000000),
194 	FIXED(MT7621_CLK_250M, "250m", 250000000),
195 	FIXED(MT7621_CLK_270M, "270m", 270000000),
196 };
197 
198 static int mt7621_register_fixed_clocks(struct device *dev,
199 					struct clk_hw_onecell_data *clk_data)
200 {
201 	struct clk_hw **hws = clk_data->hws;
202 	struct mt7621_fixed_clk *sclk;
203 	int ret, i;
204 
205 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
206 		sclk = &mt7621_fixed_clks[i];
207 		sclk->hw = clk_hw_register_fixed_rate(dev, sclk->name,
208 						      sclk->parent_name, 0,
209 						      sclk->rate);
210 		if (IS_ERR(sclk->hw)) {
211 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
212 			ret = PTR_ERR(sclk->hw);
213 			goto err_clk_unreg;
214 		}
215 
216 		hws[sclk->idx] = sclk->hw;
217 	}
218 
219 	return 0;
220 
221 err_clk_unreg:
222 	while (--i >= 0) {
223 		sclk = &mt7621_fixed_clks[i];
224 		clk_hw_unregister_fixed_rate(sclk->hw);
225 	}
226 	return ret;
227 }
228 
229 static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
230 {
231 	return container_of(hw, struct mt7621_clk, hw);
232 }
233 
234 static unsigned long mt7621_xtal_recalc_rate(struct clk_hw *hw,
235 					     unsigned long parent_rate)
236 {
237 	struct mt7621_clk *clk = to_mt7621_clk(hw);
238 	struct regmap *sysc = clk->priv->sysc;
239 	u32 val;
240 
241 	regmap_read(sysc, SYSC_REG_SYSTEM_CONFIG0, &val);
242 	val = FIELD_GET(XTAL_MODE_SEL_MASK, val);
243 
244 	if (val <= 2)
245 		return 20000000;
246 	if (val <= 5)
247 		return 40000000;
248 
249 	return 25000000;
250 }
251 
252 static unsigned long mt7621_cpu_recalc_rate(struct clk_hw *hw,
253 					    unsigned long xtal_clk)
254 {
255 	static const u32 prediv_tbl[] = { 0, 1, 2, 2 };
256 	struct mt7621_clk *clk = to_mt7621_clk(hw);
257 	struct regmap *sysc = clk->priv->sysc;
258 	struct regmap *memc = clk->priv->memc;
259 	u32 clkcfg, clk_sel, curclk, ffiv, ffrac;
260 	u32 pll, prediv, fbdiv;
261 	unsigned long cpu_clk;
262 
263 	regmap_read(sysc, SYSC_REG_CLKCFG0, &clkcfg);
264 	clk_sel = FIELD_GET(CPU_CLK_SEL_MASK, clkcfg);
265 
266 	regmap_read(sysc, SYSC_REG_CUR_CLK_STS, &curclk);
267 	ffiv = FIELD_GET(CUR_CPU_FDIV_MASK, curclk);
268 	ffrac = FIELD_GET(CUR_CPU_FFRAC_MASK, curclk);
269 
270 	switch (clk_sel) {
271 	case 0:
272 		cpu_clk = 500000000;
273 		break;
274 	case 1:
275 		regmap_read(memc, MEMC_REG_CPU_PLL, &pll);
276 		fbdiv = FIELD_GET(CPU_PLL_FBDIV_MASK, pll);
277 		prediv = FIELD_GET(CPU_PLL_PREDIV_MASK, pll);
278 		cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
279 		break;
280 	default:
281 		cpu_clk = xtal_clk;
282 	}
283 
284 	return cpu_clk / ffiv * ffrac;
285 }
286 
287 static unsigned long mt7621_bus_recalc_rate(struct clk_hw *hw,
288 					    unsigned long parent_rate)
289 {
290 	return parent_rate / 4;
291 }
292 
293 #define CLK_BASE(_name, _parent, _recalc) {				\
294 	.init = &(struct clk_init_data) {				\
295 		.name = _name,						\
296 		.ops = &(const struct clk_ops) {			\
297 			.recalc_rate = _recalc,				\
298 		},							\
299 		.parent_data = &(const struct clk_parent_data) {	\
300 			.name = _parent,				\
301 			.fw_name = _parent				\
302 		},							\
303 		.num_parents = _parent ? 1 : 0				\
304 	},								\
305 }
306 
307 static struct mt7621_clk mt7621_clks_base[] = {
308 	{ CLK_BASE("xtal", NULL, mt7621_xtal_recalc_rate) },
309 	{ CLK_BASE("cpu", "xtal", mt7621_cpu_recalc_rate) },
310 	{ CLK_BASE("bus", "cpu", mt7621_bus_recalc_rate) },
311 };
312 
313 static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
314 
315 static int mt7621_register_early_clocks(struct device_node *np,
316 					struct clk_hw_onecell_data *clk_data,
317 					struct mt7621_clk_priv *priv)
318 {
319 	struct clk_hw **hws = clk_data->hws;
320 	struct mt7621_clk *sclk;
321 	int ret, i, j;
322 
323 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
324 		sclk = &mt7621_clks_base[i];
325 		sclk->priv = priv;
326 		ret = of_clk_hw_register(np, &sclk->hw);
327 		if (ret) {
328 			pr_err("Couldn't register top clock %i\n", i);
329 			goto err_clk_unreg;
330 		}
331 
332 		hws[i] = &sclk->hw;
333 		mt7621_clk_early[i] = &sclk->hw;
334 	}
335 
336 	for (j = i; j < MT7621_CLK_MAX; j++)
337 		mt7621_clk_early[j] = ERR_PTR(-EPROBE_DEFER);
338 
339 	return 0;
340 
341 err_clk_unreg:
342 	while (--i >= 0) {
343 		sclk = &mt7621_clks_base[i];
344 		clk_hw_unregister(&sclk->hw);
345 	}
346 	return ret;
347 }
348 
349 static void __init mt7621_clk_init(struct device_node *node)
350 {
351 	struct mt7621_clk_priv *priv;
352 	struct clk_hw_onecell_data *clk_data;
353 	int ret, i, count;
354 
355 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
356 	if (!priv)
357 		return;
358 
359 	priv->sysc = syscon_node_to_regmap(node);
360 	if (IS_ERR(priv->sysc)) {
361 		pr_err("Could not get sysc syscon regmap\n");
362 		goto free_clk_priv;
363 	}
364 
365 	priv->memc = syscon_regmap_lookup_by_phandle(node, "ralink,memctl");
366 	if (IS_ERR(priv->memc)) {
367 		pr_err("Could not get memc syscon regmap\n");
368 		goto free_clk_priv;
369 	}
370 
371 	count = ARRAY_SIZE(mt7621_clks_base) +
372 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
373 	clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
374 	if (!clk_data)
375 		goto free_clk_priv;
376 
377 	ret = mt7621_register_early_clocks(node, clk_data, priv);
378 	if (ret) {
379 		pr_err("Couldn't register top clocks\n");
380 		goto free_clk_data;
381 	}
382 
383 	clk_data->num = count;
384 
385 	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
386 	if (ret) {
387 		pr_err("Couldn't add clk hw provider\n");
388 		goto unreg_clk_top;
389 	}
390 
391 	return;
392 
393 unreg_clk_top:
394 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
395 		struct mt7621_clk *sclk = &mt7621_clks_base[i];
396 
397 		clk_hw_unregister(&sclk->hw);
398 	}
399 
400 free_clk_data:
401 	kfree(clk_data);
402 
403 free_clk_priv:
404 	kfree(priv);
405 }
406 CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
407 
408 static int mt7621_clk_probe(struct platform_device *pdev)
409 {
410 	struct device_node *np = pdev->dev.of_node;
411 	struct clk_hw_onecell_data *clk_data;
412 	struct device *dev = &pdev->dev;
413 	struct mt7621_clk_priv *priv;
414 	int ret, i, count;
415 
416 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
417 	if (!priv)
418 		return -ENOMEM;
419 
420 	priv->sysc = syscon_node_to_regmap(np);
421 	if (IS_ERR(priv->sysc)) {
422 		ret = PTR_ERR(priv->sysc);
423 		dev_err(dev, "Could not get sysc syscon regmap\n");
424 		return ret;
425 	}
426 
427 	priv->memc = syscon_regmap_lookup_by_phandle(np, "ralink,memctl");
428 	if (IS_ERR(priv->memc)) {
429 		ret = PTR_ERR(priv->memc);
430 		dev_err(dev, "Could not get memc syscon regmap\n");
431 		return ret;
432 	}
433 
434 	count = ARRAY_SIZE(mt7621_clks_base) +
435 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
436 	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
437 				GFP_KERNEL);
438 	if (!clk_data)
439 		return -ENOMEM;
440 
441 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
442 		clk_data->hws[i] = mt7621_clk_early[i];
443 
444 	ret = mt7621_register_fixed_clocks(dev, clk_data);
445 	if (ret) {
446 		dev_err(dev, "Couldn't register fixed clocks\n");
447 		return ret;
448 	}
449 
450 	ret = mt7621_register_gates(dev, clk_data, priv);
451 	if (ret) {
452 		dev_err(dev, "Couldn't register fixed clock gates\n");
453 		goto unreg_clk_fixed;
454 	}
455 
456 	clk_data->num = count;
457 
458 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
459 	if (ret) {
460 		dev_err(dev, "Couldn't add clk hw provider\n");
461 		goto unreg_clk_gates;
462 	}
463 
464 	return 0;
465 
466 unreg_clk_gates:
467 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
468 		struct mt7621_gate *sclk = &mt7621_gates[i];
469 
470 		clk_hw_unregister(&sclk->hw);
471 	}
472 
473 unreg_clk_fixed:
474 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
475 		struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
476 
477 		clk_hw_unregister_fixed_rate(sclk->hw);
478 	}
479 
480 	return ret;
481 }
482 
483 static const struct of_device_id mt7621_clk_of_match[] = {
484 	{ .compatible = "mediatek,mt7621-sysc" },
485 	{}
486 };
487 
488 static struct platform_driver mt7621_clk_driver = {
489 	.probe = mt7621_clk_probe,
490 	.driver = {
491 		.name = "mt7621-clk",
492 		.of_match_table = mt7621_clk_of_match,
493 	},
494 };
495 builtin_platform_driver(mt7621_clk_driver);
496