xref: /openbmc/linux/drivers/clk/clk-xgene.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * clk-xgene.c - AppliedMicro X-Gene Clock Interface
4  *
5  * Copyright (c) 2013, Applied Micro Circuits Corporation
6  * Author: Loc Ho <lho@apm.com>
7  */
8 #include <linux/module.h>
9 #include <linux/spinlock.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk-provider.h>
14 #include <linux/of_address.h>
15 
16 /* Register SCU_PCPPLL bit fields */
17 #define N_DIV_RD(src)			((src) & 0x000001ff)
18 #define SC_N_DIV_RD(src)		((src) & 0x0000007f)
19 #define SC_OUTDIV2(src)			(((src) & 0x00000100) >> 8)
20 
21 /* Register SCU_SOCPLL bit fields */
22 #define CLKR_RD(src)			(((src) & 0x07000000)>>24)
23 #define CLKOD_RD(src)			(((src) & 0x00300000)>>20)
24 #define REGSPEC_RESET_F1_MASK		0x00010000
25 #define CLKF_RD(src)			(((src) & 0x000001ff))
26 
27 #define XGENE_CLK_DRIVER_VER		"0.1"
28 
29 static DEFINE_SPINLOCK(clk_lock);
30 
31 static inline u32 xgene_clk_read(void __iomem *csr)
32 {
33 	return readl_relaxed(csr);
34 }
35 
36 static inline void xgene_clk_write(u32 data, void __iomem *csr)
37 {
38 	writel_relaxed(data, csr);
39 }
40 
41 /* PLL Clock */
42 enum xgene_pll_type {
43 	PLL_TYPE_PCP = 0,
44 	PLL_TYPE_SOC = 1,
45 };
46 
47 struct xgene_clk_pll {
48 	struct clk_hw	hw;
49 	void __iomem	*reg;
50 	spinlock_t	*lock;
51 	u32		pll_offset;
52 	enum xgene_pll_type	type;
53 	int		version;
54 };
55 
56 #define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
57 
58 static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
59 {
60 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
61 	u32 data;
62 
63 	data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
64 	pr_debug("%s pll %s\n", clk_hw_get_name(hw),
65 		data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
66 
67 	return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
68 }
69 
70 static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
71 				unsigned long parent_rate)
72 {
73 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
74 	unsigned long fref;
75 	unsigned long fvco;
76 	u32 pll;
77 	u32 nref;
78 	u32 nout;
79 	u32 nfb;
80 
81 	pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
82 
83 	if (pllclk->version <= 1) {
84 		if (pllclk->type == PLL_TYPE_PCP) {
85 			/*
86 			* PLL VCO = Reference clock * NF
87 			* PCP PLL = PLL_VCO / 2
88 			*/
89 			nout = 2;
90 			fvco = parent_rate * (N_DIV_RD(pll) + 4);
91 		} else {
92 			/*
93 			* Fref = Reference Clock / NREF;
94 			* Fvco = Fref * NFB;
95 			* Fout = Fvco / NOUT;
96 			*/
97 			nref = CLKR_RD(pll) + 1;
98 			nout = CLKOD_RD(pll) + 1;
99 			nfb = CLKF_RD(pll);
100 			fref = parent_rate / nref;
101 			fvco = fref * nfb;
102 		}
103 	} else {
104 		/*
105 		 * fvco = Reference clock * FBDIVC
106 		 * PLL freq = fvco / NOUT
107 		 */
108 		nout = SC_OUTDIV2(pll) ? 2 : 3;
109 		fvco = parent_rate * SC_N_DIV_RD(pll);
110 	}
111 	pr_debug("%s pll recalc rate %ld parent %ld version %d\n",
112 		 clk_hw_get_name(hw), fvco / nout, parent_rate,
113 		 pllclk->version);
114 
115 	return fvco / nout;
116 }
117 
118 static const struct clk_ops xgene_clk_pll_ops = {
119 	.is_enabled = xgene_clk_pll_is_enabled,
120 	.recalc_rate = xgene_clk_pll_recalc_rate,
121 };
122 
123 static struct clk *xgene_register_clk_pll(struct device *dev,
124 	const char *name, const char *parent_name,
125 	unsigned long flags, void __iomem *reg, u32 pll_offset,
126 	u32 type, spinlock_t *lock, int version)
127 {
128 	struct xgene_clk_pll *apmclk;
129 	struct clk *clk;
130 	struct clk_init_data init;
131 
132 	/* allocate the APM clock structure */
133 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
134 	if (!apmclk)
135 		return ERR_PTR(-ENOMEM);
136 
137 	init.name = name;
138 	init.ops = &xgene_clk_pll_ops;
139 	init.flags = flags;
140 	init.parent_names = parent_name ? &parent_name : NULL;
141 	init.num_parents = parent_name ? 1 : 0;
142 
143 	apmclk->version = version;
144 	apmclk->reg = reg;
145 	apmclk->lock = lock;
146 	apmclk->pll_offset = pll_offset;
147 	apmclk->type = type;
148 	apmclk->hw.init = &init;
149 
150 	/* Register the clock */
151 	clk = clk_register(dev, &apmclk->hw);
152 	if (IS_ERR(clk)) {
153 		pr_err("%s: could not register clk %s\n", __func__, name);
154 		kfree(apmclk);
155 		return NULL;
156 	}
157 	return clk;
158 }
159 
160 static int xgene_pllclk_version(struct device_node *np)
161 {
162 	if (of_device_is_compatible(np, "apm,xgene-socpll-clock"))
163 		return 1;
164 	if (of_device_is_compatible(np, "apm,xgene-pcppll-clock"))
165 		return 1;
166 	return 2;
167 }
168 
169 static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
170 {
171 	const char *clk_name = np->full_name;
172 	struct clk *clk;
173 	void __iomem *reg;
174 	int version = xgene_pllclk_version(np);
175 
176 	reg = of_iomap(np, 0);
177 	if (!reg) {
178 		pr_err("Unable to map CSR register for %pOF\n", np);
179 		return;
180 	}
181 	of_property_read_string(np, "clock-output-names", &clk_name);
182 	clk = xgene_register_clk_pll(NULL,
183 			clk_name, of_clk_get_parent_name(np, 0),
184 			0, reg, 0, pll_type, &clk_lock,
185 			version);
186 	if (!IS_ERR(clk)) {
187 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
188 		clk_register_clkdev(clk, clk_name, NULL);
189 		pr_debug("Add %s clock PLL\n", clk_name);
190 	}
191 }
192 
193 static void xgene_socpllclk_init(struct device_node *np)
194 {
195 	xgene_pllclk_init(np, PLL_TYPE_SOC);
196 }
197 
198 static void xgene_pcppllclk_init(struct device_node *np)
199 {
200 	xgene_pllclk_init(np, PLL_TYPE_PCP);
201 }
202 
203 /**
204  * struct xgene_clk_pmd - PMD clock
205  *
206  * @hw:		handle between common and hardware-specific interfaces
207  * @reg:	register containing the fractional scale multiplier (scaler)
208  * @shift:	shift to the unit bit field
209  * @mask:	mask to the unit bit field
210  * @denom:	1/denominator unit
211  * @lock:	register lock
212  * @flags: XGENE_CLK_PMD_SCALE_INVERTED - By default the scaler is the value read
213  *	from the register plus one. For example,
214  *		0 for (0 + 1) / denom,
215  *		1 for (1 + 1) / denom and etc.
216  *	If this flag is set, it is
217  *		0 for (denom - 0) / denom,
218  *		1 for (denom - 1) / denom and etc.
219  */
220 struct xgene_clk_pmd {
221 	struct clk_hw	hw;
222 	void __iomem	*reg;
223 	u8		shift;
224 	u32		mask;
225 	u64		denom;
226 	u32		flags;
227 	spinlock_t	*lock;
228 };
229 
230 #define to_xgene_clk_pmd(_hw) container_of(_hw, struct xgene_clk_pmd, hw)
231 
232 #define XGENE_CLK_PMD_SCALE_INVERTED	BIT(0)
233 #define XGENE_CLK_PMD_SHIFT		8
234 #define XGENE_CLK_PMD_WIDTH		3
235 
236 static unsigned long xgene_clk_pmd_recalc_rate(struct clk_hw *hw,
237 					       unsigned long parent_rate)
238 {
239 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
240 	unsigned long flags = 0;
241 	u64 ret, scale;
242 	u32 val;
243 
244 	if (fd->lock)
245 		spin_lock_irqsave(fd->lock, flags);
246 	else
247 		__acquire(fd->lock);
248 
249 	val = readl(fd->reg);
250 
251 	if (fd->lock)
252 		spin_unlock_irqrestore(fd->lock, flags);
253 	else
254 		__release(fd->lock);
255 
256 	ret = (u64)parent_rate;
257 
258 	scale = (val & fd->mask) >> fd->shift;
259 	if (fd->flags & XGENE_CLK_PMD_SCALE_INVERTED)
260 		scale = fd->denom - scale;
261 	else
262 		scale++;
263 
264 	/* freq = parent_rate * scaler / denom */
265 	do_div(ret, fd->denom);
266 	ret *= scale;
267 	if (ret == 0)
268 		ret = (u64)parent_rate;
269 
270 	return ret;
271 }
272 
273 static long xgene_clk_pmd_round_rate(struct clk_hw *hw, unsigned long rate,
274 				     unsigned long *parent_rate)
275 {
276 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
277 	u64 ret, scale;
278 
279 	if (!rate || rate >= *parent_rate)
280 		return *parent_rate;
281 
282 	/* freq = parent_rate * scaler / denom */
283 	ret = rate * fd->denom;
284 	scale = DIV_ROUND_UP_ULL(ret, *parent_rate);
285 
286 	ret = (u64)*parent_rate * scale;
287 	do_div(ret, fd->denom);
288 
289 	return ret;
290 }
291 
292 static int xgene_clk_pmd_set_rate(struct clk_hw *hw, unsigned long rate,
293 				  unsigned long parent_rate)
294 {
295 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
296 	unsigned long flags = 0;
297 	u64 scale, ret;
298 	u32 val;
299 
300 	/*
301 	 * Compute the scaler:
302 	 *
303 	 * freq = parent_rate * scaler / denom, or
304 	 * scaler = freq * denom / parent_rate
305 	 */
306 	ret = rate * fd->denom;
307 	scale = DIV_ROUND_UP_ULL(ret, (u64)parent_rate);
308 
309 	/* Check if inverted */
310 	if (fd->flags & XGENE_CLK_PMD_SCALE_INVERTED)
311 		scale = fd->denom - scale;
312 	else
313 		scale--;
314 
315 	if (fd->lock)
316 		spin_lock_irqsave(fd->lock, flags);
317 	else
318 		__acquire(fd->lock);
319 
320 	val = readl(fd->reg);
321 	val &= ~fd->mask;
322 	val |= (scale << fd->shift);
323 	writel(val, fd->reg);
324 
325 	if (fd->lock)
326 		spin_unlock_irqrestore(fd->lock, flags);
327 	else
328 		__release(fd->lock);
329 
330 	return 0;
331 }
332 
333 static const struct clk_ops xgene_clk_pmd_ops = {
334 	.recalc_rate = xgene_clk_pmd_recalc_rate,
335 	.round_rate = xgene_clk_pmd_round_rate,
336 	.set_rate = xgene_clk_pmd_set_rate,
337 };
338 
339 static struct clk *
340 xgene_register_clk_pmd(struct device *dev,
341 		       const char *name, const char *parent_name,
342 		       unsigned long flags, void __iomem *reg, u8 shift,
343 		       u8 width, u64 denom, u32 clk_flags, spinlock_t *lock)
344 {
345 	struct xgene_clk_pmd *fd;
346 	struct clk_init_data init;
347 	struct clk *clk;
348 
349 	fd = kzalloc(sizeof(*fd), GFP_KERNEL);
350 	if (!fd)
351 		return ERR_PTR(-ENOMEM);
352 
353 	init.name = name;
354 	init.ops = &xgene_clk_pmd_ops;
355 	init.flags = flags;
356 	init.parent_names = parent_name ? &parent_name : NULL;
357 	init.num_parents = parent_name ? 1 : 0;
358 
359 	fd->reg = reg;
360 	fd->shift = shift;
361 	fd->mask = (BIT(width) - 1) << shift;
362 	fd->denom = denom;
363 	fd->flags = clk_flags;
364 	fd->lock = lock;
365 	fd->hw.init = &init;
366 
367 	clk = clk_register(dev, &fd->hw);
368 	if (IS_ERR(clk)) {
369 		pr_err("%s: could not register clk %s\n", __func__, name);
370 		kfree(fd);
371 		return NULL;
372 	}
373 
374 	return clk;
375 }
376 
377 static void xgene_pmdclk_init(struct device_node *np)
378 {
379 	const char *clk_name = np->full_name;
380 	void __iomem *csr_reg;
381 	struct resource res;
382 	struct clk *clk;
383 	u64 denom;
384 	u32 flags = 0;
385 	int rc;
386 
387 	/* Check if the entry is disabled */
388 	if (!of_device_is_available(np))
389 		return;
390 
391 	/* Parse the DTS register for resource */
392 	rc = of_address_to_resource(np, 0, &res);
393 	if (rc != 0) {
394 		pr_err("no DTS register for %pOF\n", np);
395 		return;
396 	}
397 	csr_reg = of_iomap(np, 0);
398 	if (!csr_reg) {
399 		pr_err("Unable to map resource for %pOF\n", np);
400 		return;
401 	}
402 	of_property_read_string(np, "clock-output-names", &clk_name);
403 
404 	denom = BIT(XGENE_CLK_PMD_WIDTH);
405 	flags |= XGENE_CLK_PMD_SCALE_INVERTED;
406 
407 	clk = xgene_register_clk_pmd(NULL, clk_name,
408 				     of_clk_get_parent_name(np, 0), 0,
409 				     csr_reg, XGENE_CLK_PMD_SHIFT,
410 				     XGENE_CLK_PMD_WIDTH, denom,
411 				     flags, &clk_lock);
412 	if (!IS_ERR(clk)) {
413 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
414 		clk_register_clkdev(clk, clk_name, NULL);
415 		pr_debug("Add %s clock\n", clk_name);
416 	} else {
417 		if (csr_reg)
418 			iounmap(csr_reg);
419 	}
420 }
421 
422 /* IP Clock */
423 struct xgene_dev_parameters {
424 	void __iomem *csr_reg;		/* CSR for IP clock */
425 	u32 reg_clk_offset;		/* Offset to clock enable CSR */
426 	u32 reg_clk_mask;		/* Mask bit for clock enable */
427 	u32 reg_csr_offset;		/* Offset to CSR reset */
428 	u32 reg_csr_mask;		/* Mask bit for disable CSR reset */
429 	void __iomem *divider_reg;	/* CSR for divider */
430 	u32 reg_divider_offset;		/* Offset to divider register */
431 	u32 reg_divider_shift;		/* Bit shift to divider field */
432 	u32 reg_divider_width;		/* Width of the bit to divider field */
433 };
434 
435 struct xgene_clk {
436 	struct clk_hw	hw;
437 	spinlock_t	*lock;
438 	struct xgene_dev_parameters	param;
439 };
440 
441 #define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
442 
443 static int xgene_clk_enable(struct clk_hw *hw)
444 {
445 	struct xgene_clk *pclk = to_xgene_clk(hw);
446 	unsigned long flags = 0;
447 	u32 data;
448 
449 	if (pclk->lock)
450 		spin_lock_irqsave(pclk->lock, flags);
451 
452 	if (pclk->param.csr_reg) {
453 		pr_debug("%s clock enabled\n", clk_hw_get_name(hw));
454 		/* First enable the clock */
455 		data = xgene_clk_read(pclk->param.csr_reg +
456 					pclk->param.reg_clk_offset);
457 		data |= pclk->param.reg_clk_mask;
458 		xgene_clk_write(data, pclk->param.csr_reg +
459 					pclk->param.reg_clk_offset);
460 		pr_debug("%s clk offset 0x%08X mask 0x%08X value 0x%08X\n",
461 			clk_hw_get_name(hw),
462 			pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
463 			data);
464 
465 		/* Second enable the CSR */
466 		data = xgene_clk_read(pclk->param.csr_reg +
467 					pclk->param.reg_csr_offset);
468 		data &= ~pclk->param.reg_csr_mask;
469 		xgene_clk_write(data, pclk->param.csr_reg +
470 					pclk->param.reg_csr_offset);
471 		pr_debug("%s csr offset 0x%08X mask 0x%08X value 0x%08X\n",
472 			clk_hw_get_name(hw),
473 			pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
474 			data);
475 	}
476 
477 	if (pclk->lock)
478 		spin_unlock_irqrestore(pclk->lock, flags);
479 
480 	return 0;
481 }
482 
483 static void xgene_clk_disable(struct clk_hw *hw)
484 {
485 	struct xgene_clk *pclk = to_xgene_clk(hw);
486 	unsigned long flags = 0;
487 	u32 data;
488 
489 	if (pclk->lock)
490 		spin_lock_irqsave(pclk->lock, flags);
491 
492 	if (pclk->param.csr_reg) {
493 		pr_debug("%s clock disabled\n", clk_hw_get_name(hw));
494 		/* First put the CSR in reset */
495 		data = xgene_clk_read(pclk->param.csr_reg +
496 					pclk->param.reg_csr_offset);
497 		data |= pclk->param.reg_csr_mask;
498 		xgene_clk_write(data, pclk->param.csr_reg +
499 					pclk->param.reg_csr_offset);
500 
501 		/* Second disable the clock */
502 		data = xgene_clk_read(pclk->param.csr_reg +
503 					pclk->param.reg_clk_offset);
504 		data &= ~pclk->param.reg_clk_mask;
505 		xgene_clk_write(data, pclk->param.csr_reg +
506 					pclk->param.reg_clk_offset);
507 	}
508 
509 	if (pclk->lock)
510 		spin_unlock_irqrestore(pclk->lock, flags);
511 }
512 
513 static int xgene_clk_is_enabled(struct clk_hw *hw)
514 {
515 	struct xgene_clk *pclk = to_xgene_clk(hw);
516 	u32 data = 0;
517 
518 	if (pclk->param.csr_reg) {
519 		pr_debug("%s clock checking\n", clk_hw_get_name(hw));
520 		data = xgene_clk_read(pclk->param.csr_reg +
521 					pclk->param.reg_clk_offset);
522 		pr_debug("%s clock is %s\n", clk_hw_get_name(hw),
523 			data & pclk->param.reg_clk_mask ? "enabled" :
524 							"disabled");
525 	}
526 
527 	if (!pclk->param.csr_reg)
528 		return 1;
529 	return data & pclk->param.reg_clk_mask ? 1 : 0;
530 }
531 
532 static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
533 				unsigned long parent_rate)
534 {
535 	struct xgene_clk *pclk = to_xgene_clk(hw);
536 	u32 data;
537 
538 	if (pclk->param.divider_reg) {
539 		data = xgene_clk_read(pclk->param.divider_reg +
540 					pclk->param.reg_divider_offset);
541 		data >>= pclk->param.reg_divider_shift;
542 		data &= (1 << pclk->param.reg_divider_width) - 1;
543 
544 		pr_debug("%s clock recalc rate %ld parent %ld\n",
545 			clk_hw_get_name(hw),
546 			parent_rate / data, parent_rate);
547 
548 		return parent_rate / data;
549 	} else {
550 		pr_debug("%s clock recalc rate %ld parent %ld\n",
551 			clk_hw_get_name(hw), parent_rate, parent_rate);
552 		return parent_rate;
553 	}
554 }
555 
556 static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
557 				unsigned long parent_rate)
558 {
559 	struct xgene_clk *pclk = to_xgene_clk(hw);
560 	unsigned long flags = 0;
561 	u32 data;
562 	u32 divider;
563 	u32 divider_save;
564 
565 	if (pclk->lock)
566 		spin_lock_irqsave(pclk->lock, flags);
567 
568 	if (pclk->param.divider_reg) {
569 		/* Let's compute the divider */
570 		if (rate > parent_rate)
571 			rate = parent_rate;
572 		divider_save = divider = parent_rate / rate; /* Rounded down */
573 		divider &= (1 << pclk->param.reg_divider_width) - 1;
574 		divider <<= pclk->param.reg_divider_shift;
575 
576 		/* Set new divider */
577 		data = xgene_clk_read(pclk->param.divider_reg +
578 				pclk->param.reg_divider_offset);
579 		data &= ~(((1 << pclk->param.reg_divider_width) - 1)
580 				<< pclk->param.reg_divider_shift);
581 		data |= divider;
582 		xgene_clk_write(data, pclk->param.divider_reg +
583 					pclk->param.reg_divider_offset);
584 		pr_debug("%s clock set rate %ld\n", clk_hw_get_name(hw),
585 			parent_rate / divider_save);
586 	} else {
587 		divider_save = 1;
588 	}
589 
590 	if (pclk->lock)
591 		spin_unlock_irqrestore(pclk->lock, flags);
592 
593 	return parent_rate / divider_save;
594 }
595 
596 static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
597 				unsigned long *prate)
598 {
599 	struct xgene_clk *pclk = to_xgene_clk(hw);
600 	unsigned long parent_rate = *prate;
601 	u32 divider;
602 
603 	if (pclk->param.divider_reg) {
604 		/* Let's compute the divider */
605 		if (rate > parent_rate)
606 			rate = parent_rate;
607 		divider = parent_rate / rate;   /* Rounded down */
608 	} else {
609 		divider = 1;
610 	}
611 
612 	return parent_rate / divider;
613 }
614 
615 static const struct clk_ops xgene_clk_ops = {
616 	.enable = xgene_clk_enable,
617 	.disable = xgene_clk_disable,
618 	.is_enabled = xgene_clk_is_enabled,
619 	.recalc_rate = xgene_clk_recalc_rate,
620 	.set_rate = xgene_clk_set_rate,
621 	.round_rate = xgene_clk_round_rate,
622 };
623 
624 static struct clk *xgene_register_clk(struct device *dev,
625 		const char *name, const char *parent_name,
626 		struct xgene_dev_parameters *parameters, spinlock_t *lock)
627 {
628 	struct xgene_clk *apmclk;
629 	struct clk *clk;
630 	struct clk_init_data init;
631 	int rc;
632 
633 	/* allocate the APM clock structure */
634 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
635 	if (!apmclk)
636 		return ERR_PTR(-ENOMEM);
637 
638 	init.name = name;
639 	init.ops = &xgene_clk_ops;
640 	init.flags = 0;
641 	init.parent_names = parent_name ? &parent_name : NULL;
642 	init.num_parents = parent_name ? 1 : 0;
643 
644 	apmclk->lock = lock;
645 	apmclk->hw.init = &init;
646 	apmclk->param = *parameters;
647 
648 	/* Register the clock */
649 	clk = clk_register(dev, &apmclk->hw);
650 	if (IS_ERR(clk)) {
651 		pr_err("%s: could not register clk %s\n", __func__, name);
652 		kfree(apmclk);
653 		return clk;
654 	}
655 
656 	/* Register the clock for lookup */
657 	rc = clk_register_clkdev(clk, name, NULL);
658 	if (rc != 0) {
659 		pr_err("%s: could not register lookup clk %s\n",
660 			__func__, name);
661 	}
662 	return clk;
663 }
664 
665 static void __init xgene_devclk_init(struct device_node *np)
666 {
667 	const char *clk_name = np->full_name;
668 	struct clk *clk;
669 	struct resource res;
670 	int rc;
671 	struct xgene_dev_parameters parameters;
672 	int i;
673 
674 	/* Check if the entry is disabled */
675         if (!of_device_is_available(np))
676                 return;
677 
678 	/* Parse the DTS register for resource */
679 	parameters.csr_reg = NULL;
680 	parameters.divider_reg = NULL;
681 	for (i = 0; i < 2; i++) {
682 		void __iomem *map_res;
683 		rc = of_address_to_resource(np, i, &res);
684 		if (rc != 0) {
685 			if (i == 0) {
686 				pr_err("no DTS register for %pOF\n", np);
687 				return;
688 			}
689 			break;
690 		}
691 		map_res = of_iomap(np, i);
692 		if (!map_res) {
693 			pr_err("Unable to map resource %d for %pOF\n", i, np);
694 			goto err;
695 		}
696 		if (strcmp(res.name, "div-reg") == 0)
697 			parameters.divider_reg = map_res;
698 		else /* if (strcmp(res->name, "csr-reg") == 0) */
699 			parameters.csr_reg = map_res;
700 	}
701 	if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
702 		parameters.reg_csr_offset = 0;
703 	if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
704 		parameters.reg_csr_mask = 0xF;
705 	if (of_property_read_u32(np, "enable-offset",
706 				&parameters.reg_clk_offset))
707 		parameters.reg_clk_offset = 0x8;
708 	if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
709 		parameters.reg_clk_mask = 0xF;
710 	if (of_property_read_u32(np, "divider-offset",
711 				&parameters.reg_divider_offset))
712 		parameters.reg_divider_offset = 0;
713 	if (of_property_read_u32(np, "divider-width",
714 				&parameters.reg_divider_width))
715 		parameters.reg_divider_width = 0;
716 	if (of_property_read_u32(np, "divider-shift",
717 				&parameters.reg_divider_shift))
718 		parameters.reg_divider_shift = 0;
719 	of_property_read_string(np, "clock-output-names", &clk_name);
720 
721 	clk = xgene_register_clk(NULL, clk_name,
722 		of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
723 	if (IS_ERR(clk))
724 		goto err;
725 	pr_debug("Add %s clock\n", clk_name);
726 	rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
727 	if (rc != 0)
728 		pr_err("%s: could register provider clk %pOF\n", __func__, np);
729 
730 	return;
731 
732 err:
733 	if (parameters.csr_reg)
734 		iounmap(parameters.csr_reg);
735 	if (parameters.divider_reg)
736 		iounmap(parameters.divider_reg);
737 }
738 
739 CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
740 CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
741 CLK_OF_DECLARE(xgene_pmd_clock, "apm,xgene-pmd-clock", xgene_pmdclk_init);
742 CLK_OF_DECLARE(xgene_socpll_v2_clock, "apm,xgene-socpll-v2-clock",
743 	       xgene_socpllclk_init);
744 CLK_OF_DECLARE(xgene_pcppll_v2_clock, "apm,xgene-pcppll-v2-clock",
745 	       xgene_pcppllclk_init);
746 CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
747