xref: /openbmc/linux/drivers/clk/ralink/clk-mt7621.c (revision 8d753db5)
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 		.flags = CLK_SET_RATE_PARENT,
135 		.num_parents = 1,
136 		.parent_names = &sclk->parent_name,
137 		.ops = &mt7621_gate_ops,
138 		.name = sclk->name,
139 	};
140 
141 	sclk->hw.init = &init;
142 	return devm_clk_hw_register(dev, &sclk->hw);
143 }
144 
145 static int mt7621_register_gates(struct device *dev,
146 				 struct clk_hw_onecell_data *clk_data,
147 				 struct mt7621_clk_priv *priv)
148 {
149 	struct clk_hw **hws = clk_data->hws;
150 	struct mt7621_gate *sclk;
151 	int ret, i;
152 
153 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
154 		sclk = &mt7621_gates[i];
155 		sclk->priv = priv;
156 		ret = mt7621_gate_ops_init(dev, sclk);
157 		if (ret) {
158 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
159 			goto err_clk_unreg;
160 		}
161 
162 		hws[sclk->idx] = &sclk->hw;
163 	}
164 
165 	return 0;
166 
167 err_clk_unreg:
168 	while (--i >= 0) {
169 		sclk = &mt7621_gates[i];
170 		clk_hw_unregister(&sclk->hw);
171 	}
172 	return ret;
173 }
174 
175 #define FIXED(_id, _name, _rate)		\
176 	{					\
177 		.idx		= _id,		\
178 		.name		= _name,	\
179 		.parent_name	= "xtal",	\
180 		.rate		= _rate		\
181 	}
182 
183 static struct mt7621_fixed_clk mt7621_fixed_clks[] = {
184 	FIXED(MT7621_CLK_50M, "50m", 50000000),
185 	FIXED(MT7621_CLK_125M, "125m", 125000000),
186 	FIXED(MT7621_CLK_150M, "150m", 150000000),
187 	FIXED(MT7621_CLK_250M, "250m", 250000000),
188 	FIXED(MT7621_CLK_270M, "270m", 270000000),
189 };
190 
191 static int mt7621_register_fixed_clocks(struct device *dev,
192 					struct clk_hw_onecell_data *clk_data)
193 {
194 	struct clk_hw **hws = clk_data->hws;
195 	struct mt7621_fixed_clk *sclk;
196 	int ret, i;
197 
198 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
199 		sclk = &mt7621_fixed_clks[i];
200 		sclk->hw = clk_hw_register_fixed_rate(dev, sclk->name,
201 						      sclk->parent_name, 0,
202 						      sclk->rate);
203 		if (IS_ERR(sclk->hw)) {
204 			dev_err(dev, "Couldn't register clock %s\n", sclk->name);
205 			ret = PTR_ERR(sclk->hw);
206 			goto err_clk_unreg;
207 		}
208 
209 		hws[sclk->idx] = sclk->hw;
210 	}
211 
212 	return 0;
213 
214 err_clk_unreg:
215 	while (--i >= 0) {
216 		sclk = &mt7621_fixed_clks[i];
217 		clk_hw_unregister_fixed_rate(sclk->hw);
218 	}
219 	return ret;
220 }
221 
222 static inline struct mt7621_clk *to_mt7621_clk(struct clk_hw *hw)
223 {
224 	return container_of(hw, struct mt7621_clk, hw);
225 }
226 
227 static unsigned long mt7621_xtal_recalc_rate(struct clk_hw *hw,
228 					     unsigned long parent_rate)
229 {
230 	struct mt7621_clk *clk = to_mt7621_clk(hw);
231 	struct regmap *sysc = clk->priv->sysc;
232 	u32 val;
233 
234 	regmap_read(sysc, SYSC_REG_SYSTEM_CONFIG0, &val);
235 	val = FIELD_GET(XTAL_MODE_SEL_MASK, val);
236 
237 	if (val <= 2)
238 		return 20000000;
239 	if (val <= 5)
240 		return 40000000;
241 
242 	return 25000000;
243 }
244 
245 static unsigned long mt7621_cpu_recalc_rate(struct clk_hw *hw,
246 					    unsigned long xtal_clk)
247 {
248 	static const u32 prediv_tbl[] = { 0, 1, 2, 2 };
249 	struct mt7621_clk *clk = to_mt7621_clk(hw);
250 	struct regmap *sysc = clk->priv->sysc;
251 	struct regmap *memc = clk->priv->memc;
252 	u32 clkcfg, clk_sel, curclk, ffiv, ffrac;
253 	u32 pll, prediv, fbdiv;
254 	unsigned long cpu_clk;
255 
256 	regmap_read(sysc, SYSC_REG_CLKCFG0, &clkcfg);
257 	clk_sel = FIELD_GET(CPU_CLK_SEL_MASK, clkcfg);
258 
259 	regmap_read(sysc, SYSC_REG_CUR_CLK_STS, &curclk);
260 	ffiv = FIELD_GET(CUR_CPU_FDIV_MASK, curclk);
261 	ffrac = FIELD_GET(CUR_CPU_FFRAC_MASK, curclk);
262 
263 	switch (clk_sel) {
264 	case 0:
265 		cpu_clk = 500000000;
266 		break;
267 	case 1:
268 		regmap_read(memc, MEMC_REG_CPU_PLL, &pll);
269 		fbdiv = FIELD_GET(CPU_PLL_FBDIV_MASK, pll);
270 		prediv = FIELD_GET(CPU_PLL_PREDIV_MASK, pll);
271 		cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv];
272 		break;
273 	default:
274 		cpu_clk = xtal_clk;
275 	}
276 
277 	return cpu_clk / ffiv * ffrac;
278 }
279 
280 static unsigned long mt7621_bus_recalc_rate(struct clk_hw *hw,
281 					    unsigned long parent_rate)
282 {
283 	return parent_rate / 4;
284 }
285 
286 #define CLK_BASE(_name, _parent, _recalc) {				\
287 	.init = &(struct clk_init_data) {				\
288 		.name = _name,						\
289 		.ops = &(const struct clk_ops) {			\
290 			.recalc_rate = _recalc,				\
291 		},							\
292 		.parent_data = &(const struct clk_parent_data) {	\
293 			.name = _parent,				\
294 			.fw_name = _parent				\
295 		},							\
296 		.num_parents = _parent ? 1 : 0				\
297 	},								\
298 }
299 
300 static struct mt7621_clk mt7621_clks_base[] = {
301 	{ CLK_BASE("xtal", NULL, mt7621_xtal_recalc_rate) },
302 	{ CLK_BASE("cpu", "xtal", mt7621_cpu_recalc_rate) },
303 	{ CLK_BASE("bus", "cpu", mt7621_bus_recalc_rate) },
304 };
305 
306 static struct clk_hw *mt7621_clk_early[MT7621_CLK_MAX];
307 
308 static int mt7621_register_early_clocks(struct device_node *np,
309 					struct clk_hw_onecell_data *clk_data,
310 					struct mt7621_clk_priv *priv)
311 {
312 	struct clk_hw **hws = clk_data->hws;
313 	struct mt7621_clk *sclk;
314 	int ret, i, j;
315 
316 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
317 		sclk = &mt7621_clks_base[i];
318 		sclk->priv = priv;
319 		ret = of_clk_hw_register(np, &sclk->hw);
320 		if (ret) {
321 			pr_err("Couldn't register top clock %i\n", i);
322 			goto err_clk_unreg;
323 		}
324 
325 		hws[i] = &sclk->hw;
326 		mt7621_clk_early[i] = &sclk->hw;
327 	}
328 
329 	for (j = i; j < MT7621_CLK_MAX; j++)
330 		mt7621_clk_early[j] = ERR_PTR(-EPROBE_DEFER);
331 
332 	return 0;
333 
334 err_clk_unreg:
335 	while (--i >= 0) {
336 		sclk = &mt7621_clks_base[i];
337 		clk_hw_unregister(&sclk->hw);
338 	}
339 	return ret;
340 }
341 
342 static void __init mt7621_clk_init(struct device_node *node)
343 {
344 	struct mt7621_clk_priv *priv;
345 	struct clk_hw_onecell_data *clk_data;
346 	int ret, i, count;
347 
348 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
349 	if (!priv)
350 		return;
351 
352 	priv->sysc = syscon_node_to_regmap(node);
353 	if (IS_ERR(priv->sysc)) {
354 		pr_err("Could not get sysc syscon regmap\n");
355 		goto free_clk_priv;
356 	}
357 
358 	priv->memc = syscon_regmap_lookup_by_phandle(node, "ralink,memctl");
359 	if (IS_ERR(priv->memc)) {
360 		pr_err("Could not get memc syscon regmap\n");
361 		goto free_clk_priv;
362 	}
363 
364 	count = ARRAY_SIZE(mt7621_clks_base) +
365 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
366 	clk_data = kzalloc(struct_size(clk_data, hws, count), GFP_KERNEL);
367 	if (!clk_data)
368 		goto free_clk_priv;
369 
370 	ret = mt7621_register_early_clocks(node, clk_data, priv);
371 	if (ret) {
372 		pr_err("Couldn't register top clocks\n");
373 		goto free_clk_data;
374 	}
375 
376 	clk_data->num = count;
377 
378 	ret = of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
379 	if (ret) {
380 		pr_err("Couldn't add clk hw provider\n");
381 		goto unreg_clk_top;
382 	}
383 
384 	return;
385 
386 unreg_clk_top:
387 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++) {
388 		struct mt7621_clk *sclk = &mt7621_clks_base[i];
389 
390 		clk_hw_unregister(&sclk->hw);
391 	}
392 
393 free_clk_data:
394 	kfree(clk_data);
395 
396 free_clk_priv:
397 	kfree(priv);
398 }
399 CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
400 
401 static int mt7621_clk_probe(struct platform_device *pdev)
402 {
403 	struct device_node *np = pdev->dev.of_node;
404 	struct clk_hw_onecell_data *clk_data;
405 	struct device *dev = &pdev->dev;
406 	struct mt7621_clk_priv *priv;
407 	int ret, i, count;
408 
409 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
410 	if (!priv)
411 		return -ENOMEM;
412 
413 	priv->sysc = syscon_node_to_regmap(np);
414 	if (IS_ERR(priv->sysc)) {
415 		ret = PTR_ERR(priv->sysc);
416 		dev_err(dev, "Could not get sysc syscon regmap\n");
417 		return ret;
418 	}
419 
420 	priv->memc = syscon_regmap_lookup_by_phandle(np, "ralink,memctl");
421 	if (IS_ERR(priv->memc)) {
422 		ret = PTR_ERR(priv->memc);
423 		dev_err(dev, "Could not get memc syscon regmap\n");
424 		return ret;
425 	}
426 
427 	count = ARRAY_SIZE(mt7621_clks_base) +
428 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
429 	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
430 				GFP_KERNEL);
431 	if (!clk_data)
432 		return -ENOMEM;
433 
434 	for (i = 0; i < ARRAY_SIZE(mt7621_clks_base); i++)
435 		clk_data->hws[i] = mt7621_clk_early[i];
436 
437 	ret = mt7621_register_fixed_clocks(dev, clk_data);
438 	if (ret) {
439 		dev_err(dev, "Couldn't register fixed clocks\n");
440 		return ret;
441 	}
442 
443 	ret = mt7621_register_gates(dev, clk_data, priv);
444 	if (ret) {
445 		dev_err(dev, "Couldn't register fixed clock gates\n");
446 		goto unreg_clk_fixed;
447 	}
448 
449 	clk_data->num = count;
450 
451 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
452 	if (ret) {
453 		dev_err(dev, "Couldn't add clk hw provider\n");
454 		goto unreg_clk_gates;
455 	}
456 
457 	return 0;
458 
459 unreg_clk_gates:
460 	for (i = 0; i < ARRAY_SIZE(mt7621_gates); i++) {
461 		struct mt7621_gate *sclk = &mt7621_gates[i];
462 
463 		clk_hw_unregister(&sclk->hw);
464 	}
465 
466 unreg_clk_fixed:
467 	for (i = 0; i < ARRAY_SIZE(mt7621_fixed_clks); i++) {
468 		struct mt7621_fixed_clk *sclk = &mt7621_fixed_clks[i];
469 
470 		clk_hw_unregister_fixed_rate(sclk->hw);
471 	}
472 
473 	return ret;
474 }
475 
476 static const struct of_device_id mt7621_clk_of_match[] = {
477 	{ .compatible = "mediatek,mt7621-sysc" },
478 	{}
479 };
480 
481 static struct platform_driver mt7621_clk_driver = {
482 	.probe = mt7621_clk_probe,
483 	.driver = {
484 		.name = "mt7621-clk",
485 		.of_match_table = mt7621_clk_of_match,
486 	},
487 };
488 builtin_platform_driver(mt7621_clk_driver);
489