xref: /linux/drivers/clk/clk-xgene.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  * clk-xgene.c - AppliedMicro X-Gene Clock Interface
3  *
4  * Copyright (c) 2013, Applied Micro Circuits Corporation
5  * Author: Loc Ho <lho@apm.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20  * MA 02111-1307 USA
21  *
22  */
23 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/io.h>
26 #include <linux/of.h>
27 #include <linux/clkdev.h>
28 #include <linux/clk-provider.h>
29 #include <linux/of_address.h>
30 
31 /* Register SCU_PCPPLL bit fields */
32 #define N_DIV_RD(src)			((src) & 0x000001ff)
33 #define SC_N_DIV_RD(src)		((src) & 0x0000007f)
34 #define SC_OUTDIV2(src)			(((src) & 0x00000100) >> 8)
35 
36 /* Register SCU_SOCPLL bit fields */
37 #define CLKR_RD(src)			(((src) & 0x07000000)>>24)
38 #define CLKOD_RD(src)			(((src) & 0x00300000)>>20)
39 #define REGSPEC_RESET_F1_MASK		0x00010000
40 #define CLKF_RD(src)			(((src) & 0x000001ff))
41 
42 #define XGENE_CLK_DRIVER_VER		"0.1"
43 
44 static DEFINE_SPINLOCK(clk_lock);
45 
46 static inline u32 xgene_clk_read(void __iomem *csr)
47 {
48 	return readl_relaxed(csr);
49 }
50 
51 static inline void xgene_clk_write(u32 data, void __iomem *csr)
52 {
53 	writel_relaxed(data, csr);
54 }
55 
56 /* PLL Clock */
57 enum xgene_pll_type {
58 	PLL_TYPE_PCP = 0,
59 	PLL_TYPE_SOC = 1,
60 };
61 
62 struct xgene_clk_pll {
63 	struct clk_hw	hw;
64 	void __iomem	*reg;
65 	spinlock_t	*lock;
66 	u32		pll_offset;
67 	enum xgene_pll_type	type;
68 	int		version;
69 };
70 
71 #define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
72 
73 static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
74 {
75 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
76 	u32 data;
77 
78 	data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
79 	pr_debug("%s pll %s\n", clk_hw_get_name(hw),
80 		data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
81 
82 	return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
83 }
84 
85 static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
86 				unsigned long parent_rate)
87 {
88 	struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
89 	unsigned long fref;
90 	unsigned long fvco;
91 	u32 pll;
92 	u32 nref;
93 	u32 nout;
94 	u32 nfb;
95 
96 	pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
97 
98 	if (pllclk->version <= 1) {
99 		if (pllclk->type == PLL_TYPE_PCP) {
100 			/*
101 			* PLL VCO = Reference clock * NF
102 			* PCP PLL = PLL_VCO / 2
103 			*/
104 			nout = 2;
105 			fvco = parent_rate * (N_DIV_RD(pll) + 4);
106 		} else {
107 			/*
108 			* Fref = Reference Clock / NREF;
109 			* Fvco = Fref * NFB;
110 			* Fout = Fvco / NOUT;
111 			*/
112 			nref = CLKR_RD(pll) + 1;
113 			nout = CLKOD_RD(pll) + 1;
114 			nfb = CLKF_RD(pll);
115 			fref = parent_rate / nref;
116 			fvco = fref * nfb;
117 		}
118 	} else {
119 		/*
120 		 * fvco = Reference clock * FBDIVC
121 		 * PLL freq = fvco / NOUT
122 		 */
123 		nout = SC_OUTDIV2(pll) ? 2 : 3;
124 		fvco = parent_rate * SC_N_DIV_RD(pll);
125 	}
126 	pr_debug("%s pll recalc rate %ld parent %ld version %d\n",
127 		 clk_hw_get_name(hw), fvco / nout, parent_rate,
128 		 pllclk->version);
129 
130 	return fvco / nout;
131 }
132 
133 static const struct clk_ops xgene_clk_pll_ops = {
134 	.is_enabled = xgene_clk_pll_is_enabled,
135 	.recalc_rate = xgene_clk_pll_recalc_rate,
136 };
137 
138 static struct clk *xgene_register_clk_pll(struct device *dev,
139 	const char *name, const char *parent_name,
140 	unsigned long flags, void __iomem *reg, u32 pll_offset,
141 	u32 type, spinlock_t *lock, int version)
142 {
143 	struct xgene_clk_pll *apmclk;
144 	struct clk *clk;
145 	struct clk_init_data init;
146 
147 	/* allocate the APM clock structure */
148 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
149 	if (!apmclk)
150 		return ERR_PTR(-ENOMEM);
151 
152 	init.name = name;
153 	init.ops = &xgene_clk_pll_ops;
154 	init.flags = flags;
155 	init.parent_names = parent_name ? &parent_name : NULL;
156 	init.num_parents = parent_name ? 1 : 0;
157 
158 	apmclk->version = version;
159 	apmclk->reg = reg;
160 	apmclk->lock = lock;
161 	apmclk->pll_offset = pll_offset;
162 	apmclk->type = type;
163 	apmclk->hw.init = &init;
164 
165 	/* Register the clock */
166 	clk = clk_register(dev, &apmclk->hw);
167 	if (IS_ERR(clk)) {
168 		pr_err("%s: could not register clk %s\n", __func__, name);
169 		kfree(apmclk);
170 		return NULL;
171 	}
172 	return clk;
173 }
174 
175 static int xgene_pllclk_version(struct device_node *np)
176 {
177 	if (of_device_is_compatible(np, "apm,xgene-socpll-clock"))
178 		return 1;
179 	if (of_device_is_compatible(np, "apm,xgene-pcppll-clock"))
180 		return 1;
181 	return 2;
182 }
183 
184 static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
185 {
186 	const char *clk_name = np->full_name;
187 	struct clk *clk;
188 	void __iomem *reg;
189 	int version = xgene_pllclk_version(np);
190 
191 	reg = of_iomap(np, 0);
192 	if (!reg) {
193 		pr_err("Unable to map CSR register for %pOF\n", np);
194 		return;
195 	}
196 	of_property_read_string(np, "clock-output-names", &clk_name);
197 	clk = xgene_register_clk_pll(NULL,
198 			clk_name, of_clk_get_parent_name(np, 0),
199 			0, reg, 0, pll_type, &clk_lock,
200 			version);
201 	if (!IS_ERR(clk)) {
202 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
203 		clk_register_clkdev(clk, clk_name, NULL);
204 		pr_debug("Add %s clock PLL\n", clk_name);
205 	}
206 }
207 
208 static void xgene_socpllclk_init(struct device_node *np)
209 {
210 	xgene_pllclk_init(np, PLL_TYPE_SOC);
211 }
212 
213 static void xgene_pcppllclk_init(struct device_node *np)
214 {
215 	xgene_pllclk_init(np, PLL_TYPE_PCP);
216 }
217 
218 /**
219  * struct xgene_clk_pmd - PMD clock
220  *
221  * @hw:		handle between common and hardware-specific interfaces
222  * @reg:	register containing the fractional scale multiplier (scaler)
223  * @shift:	shift to the unit bit field
224  * @denom:	1/denominator unit
225  * @lock:	register lock
226  * Flags:
227  * XGENE_CLK_PMD_SCALE_INVERTED - By default the scaler is the value read
228  *	from the register plus one. For example,
229  *		0 for (0 + 1) / denom,
230  *		1 for (1 + 1) / denom and etc.
231  *	If this flag is set, it is
232  *		0 for (denom - 0) / denom,
233  *		1 for (denom - 1) / denom and etc.
234  *
235  */
236 struct xgene_clk_pmd {
237 	struct clk_hw	hw;
238 	void __iomem	*reg;
239 	u8		shift;
240 	u32		mask;
241 	u64		denom;
242 	u32		flags;
243 	spinlock_t	*lock;
244 };
245 
246 #define to_xgene_clk_pmd(_hw) container_of(_hw, struct xgene_clk_pmd, hw)
247 
248 #define XGENE_CLK_PMD_SCALE_INVERTED	BIT(0)
249 #define XGENE_CLK_PMD_SHIFT		8
250 #define XGENE_CLK_PMD_WIDTH		3
251 
252 static unsigned long xgene_clk_pmd_recalc_rate(struct clk_hw *hw,
253 					       unsigned long parent_rate)
254 {
255 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
256 	unsigned long flags = 0;
257 	u64 ret, scale;
258 	u32 val;
259 
260 	if (fd->lock)
261 		spin_lock_irqsave(fd->lock, flags);
262 	else
263 		__acquire(fd->lock);
264 
265 	val = clk_readl(fd->reg);
266 
267 	if (fd->lock)
268 		spin_unlock_irqrestore(fd->lock, flags);
269 	else
270 		__release(fd->lock);
271 
272 	ret = (u64)parent_rate;
273 
274 	scale = (val & fd->mask) >> fd->shift;
275 	if (fd->flags & XGENE_CLK_PMD_SCALE_INVERTED)
276 		scale = fd->denom - scale;
277 	else
278 		scale++;
279 
280 	/* freq = parent_rate * scaler / denom */
281 	do_div(ret, fd->denom);
282 	ret *= scale;
283 	if (ret == 0)
284 		ret = (u64)parent_rate;
285 
286 	return ret;
287 }
288 
289 static long xgene_clk_pmd_round_rate(struct clk_hw *hw, unsigned long rate,
290 				     unsigned long *parent_rate)
291 {
292 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
293 	u64 ret, scale;
294 
295 	if (!rate || rate >= *parent_rate)
296 		return *parent_rate;
297 
298 	/* freq = parent_rate * scaler / denom */
299 	ret = rate * fd->denom;
300 	scale = DIV_ROUND_UP_ULL(ret, *parent_rate);
301 
302 	ret = (u64)*parent_rate * scale;
303 	do_div(ret, fd->denom);
304 
305 	return ret;
306 }
307 
308 static int xgene_clk_pmd_set_rate(struct clk_hw *hw, unsigned long rate,
309 				  unsigned long parent_rate)
310 {
311 	struct xgene_clk_pmd *fd = to_xgene_clk_pmd(hw);
312 	unsigned long flags = 0;
313 	u64 scale, ret;
314 	u32 val;
315 
316 	/*
317 	 * Compute the scaler:
318 	 *
319 	 * freq = parent_rate * scaler / denom, or
320 	 * scaler = freq * denom / parent_rate
321 	 */
322 	ret = rate * fd->denom;
323 	scale = DIV_ROUND_UP_ULL(ret, (u64)parent_rate);
324 
325 	/* Check if inverted */
326 	if (fd->flags & XGENE_CLK_PMD_SCALE_INVERTED)
327 		scale = fd->denom - scale;
328 	else
329 		scale--;
330 
331 	if (fd->lock)
332 		spin_lock_irqsave(fd->lock, flags);
333 	else
334 		__acquire(fd->lock);
335 
336 	val = clk_readl(fd->reg);
337 	val &= ~fd->mask;
338 	val |= (scale << fd->shift);
339 	clk_writel(val, fd->reg);
340 
341 	if (fd->lock)
342 		spin_unlock_irqrestore(fd->lock, flags);
343 	else
344 		__release(fd->lock);
345 
346 	return 0;
347 }
348 
349 static const struct clk_ops xgene_clk_pmd_ops = {
350 	.recalc_rate = xgene_clk_pmd_recalc_rate,
351 	.round_rate = xgene_clk_pmd_round_rate,
352 	.set_rate = xgene_clk_pmd_set_rate,
353 };
354 
355 static struct clk *
356 xgene_register_clk_pmd(struct device *dev,
357 		       const char *name, const char *parent_name,
358 		       unsigned long flags, void __iomem *reg, u8 shift,
359 		       u8 width, u64 denom, u32 clk_flags, spinlock_t *lock)
360 {
361 	struct xgene_clk_pmd *fd;
362 	struct clk_init_data init;
363 	struct clk *clk;
364 
365 	fd = kzalloc(sizeof(*fd), GFP_KERNEL);
366 	if (!fd)
367 		return ERR_PTR(-ENOMEM);
368 
369 	init.name = name;
370 	init.ops = &xgene_clk_pmd_ops;
371 	init.flags = flags;
372 	init.parent_names = parent_name ? &parent_name : NULL;
373 	init.num_parents = parent_name ? 1 : 0;
374 
375 	fd->reg = reg;
376 	fd->shift = shift;
377 	fd->mask = (BIT(width) - 1) << shift;
378 	fd->denom = denom;
379 	fd->flags = clk_flags;
380 	fd->lock = lock;
381 	fd->hw.init = &init;
382 
383 	clk = clk_register(dev, &fd->hw);
384 	if (IS_ERR(clk)) {
385 		pr_err("%s: could not register clk %s\n", __func__, name);
386 		kfree(fd);
387 		return NULL;
388 	}
389 
390 	return clk;
391 }
392 
393 static void xgene_pmdclk_init(struct device_node *np)
394 {
395 	const char *clk_name = np->full_name;
396 	void __iomem *csr_reg;
397 	struct resource res;
398 	struct clk *clk;
399 	u64 denom;
400 	u32 flags = 0;
401 	int rc;
402 
403 	/* Check if the entry is disabled */
404 	if (!of_device_is_available(np))
405 		return;
406 
407 	/* Parse the DTS register for resource */
408 	rc = of_address_to_resource(np, 0, &res);
409 	if (rc != 0) {
410 		pr_err("no DTS register for %pOF\n", np);
411 		return;
412 	}
413 	csr_reg = of_iomap(np, 0);
414 	if (!csr_reg) {
415 		pr_err("Unable to map resource for %pOF\n", np);
416 		return;
417 	}
418 	of_property_read_string(np, "clock-output-names", &clk_name);
419 
420 	denom = BIT(XGENE_CLK_PMD_WIDTH);
421 	flags |= XGENE_CLK_PMD_SCALE_INVERTED;
422 
423 	clk = xgene_register_clk_pmd(NULL, clk_name,
424 				     of_clk_get_parent_name(np, 0), 0,
425 				     csr_reg, XGENE_CLK_PMD_SHIFT,
426 				     XGENE_CLK_PMD_WIDTH, denom,
427 				     flags, &clk_lock);
428 	if (!IS_ERR(clk)) {
429 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
430 		clk_register_clkdev(clk, clk_name, NULL);
431 		pr_debug("Add %s clock\n", clk_name);
432 	} else {
433 		if (csr_reg)
434 			iounmap(csr_reg);
435 	}
436 }
437 
438 /* IP Clock */
439 struct xgene_dev_parameters {
440 	void __iomem *csr_reg;		/* CSR for IP clock */
441 	u32 reg_clk_offset;		/* Offset to clock enable CSR */
442 	u32 reg_clk_mask;		/* Mask bit for clock enable */
443 	u32 reg_csr_offset;		/* Offset to CSR reset */
444 	u32 reg_csr_mask;		/* Mask bit for disable CSR reset */
445 	void __iomem *divider_reg;	/* CSR for divider */
446 	u32 reg_divider_offset;		/* Offset to divider register */
447 	u32 reg_divider_shift;		/* Bit shift to divider field */
448 	u32 reg_divider_width;		/* Width of the bit to divider field */
449 };
450 
451 struct xgene_clk {
452 	struct clk_hw	hw;
453 	spinlock_t	*lock;
454 	struct xgene_dev_parameters	param;
455 };
456 
457 #define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
458 
459 static int xgene_clk_enable(struct clk_hw *hw)
460 {
461 	struct xgene_clk *pclk = to_xgene_clk(hw);
462 	unsigned long flags = 0;
463 	u32 data;
464 
465 	if (pclk->lock)
466 		spin_lock_irqsave(pclk->lock, flags);
467 
468 	if (pclk->param.csr_reg) {
469 		pr_debug("%s clock enabled\n", clk_hw_get_name(hw));
470 		/* First enable the clock */
471 		data = xgene_clk_read(pclk->param.csr_reg +
472 					pclk->param.reg_clk_offset);
473 		data |= pclk->param.reg_clk_mask;
474 		xgene_clk_write(data, pclk->param.csr_reg +
475 					pclk->param.reg_clk_offset);
476 		pr_debug("%s clk offset 0x%08X mask 0x%08X value 0x%08X\n",
477 			clk_hw_get_name(hw),
478 			pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
479 			data);
480 
481 		/* Second enable the CSR */
482 		data = xgene_clk_read(pclk->param.csr_reg +
483 					pclk->param.reg_csr_offset);
484 		data &= ~pclk->param.reg_csr_mask;
485 		xgene_clk_write(data, pclk->param.csr_reg +
486 					pclk->param.reg_csr_offset);
487 		pr_debug("%s csr offset 0x%08X mask 0x%08X value 0x%08X\n",
488 			clk_hw_get_name(hw),
489 			pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
490 			data);
491 	}
492 
493 	if (pclk->lock)
494 		spin_unlock_irqrestore(pclk->lock, flags);
495 
496 	return 0;
497 }
498 
499 static void xgene_clk_disable(struct clk_hw *hw)
500 {
501 	struct xgene_clk *pclk = to_xgene_clk(hw);
502 	unsigned long flags = 0;
503 	u32 data;
504 
505 	if (pclk->lock)
506 		spin_lock_irqsave(pclk->lock, flags);
507 
508 	if (pclk->param.csr_reg) {
509 		pr_debug("%s clock disabled\n", clk_hw_get_name(hw));
510 		/* First put the CSR in reset */
511 		data = xgene_clk_read(pclk->param.csr_reg +
512 					pclk->param.reg_csr_offset);
513 		data |= pclk->param.reg_csr_mask;
514 		xgene_clk_write(data, pclk->param.csr_reg +
515 					pclk->param.reg_csr_offset);
516 
517 		/* Second disable the clock */
518 		data = xgene_clk_read(pclk->param.csr_reg +
519 					pclk->param.reg_clk_offset);
520 		data &= ~pclk->param.reg_clk_mask;
521 		xgene_clk_write(data, pclk->param.csr_reg +
522 					pclk->param.reg_clk_offset);
523 	}
524 
525 	if (pclk->lock)
526 		spin_unlock_irqrestore(pclk->lock, flags);
527 }
528 
529 static int xgene_clk_is_enabled(struct clk_hw *hw)
530 {
531 	struct xgene_clk *pclk = to_xgene_clk(hw);
532 	u32 data = 0;
533 
534 	if (pclk->param.csr_reg) {
535 		pr_debug("%s clock checking\n", clk_hw_get_name(hw));
536 		data = xgene_clk_read(pclk->param.csr_reg +
537 					pclk->param.reg_clk_offset);
538 		pr_debug("%s clock is %s\n", clk_hw_get_name(hw),
539 			data & pclk->param.reg_clk_mask ? "enabled" :
540 							"disabled");
541 	}
542 
543 	if (!pclk->param.csr_reg)
544 		return 1;
545 	return data & pclk->param.reg_clk_mask ? 1 : 0;
546 }
547 
548 static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
549 				unsigned long parent_rate)
550 {
551 	struct xgene_clk *pclk = to_xgene_clk(hw);
552 	u32 data;
553 
554 	if (pclk->param.divider_reg) {
555 		data = xgene_clk_read(pclk->param.divider_reg +
556 					pclk->param.reg_divider_offset);
557 		data >>= pclk->param.reg_divider_shift;
558 		data &= (1 << pclk->param.reg_divider_width) - 1;
559 
560 		pr_debug("%s clock recalc rate %ld parent %ld\n",
561 			clk_hw_get_name(hw),
562 			parent_rate / data, parent_rate);
563 
564 		return parent_rate / data;
565 	} else {
566 		pr_debug("%s clock recalc rate %ld parent %ld\n",
567 			clk_hw_get_name(hw), parent_rate, parent_rate);
568 		return parent_rate;
569 	}
570 }
571 
572 static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
573 				unsigned long parent_rate)
574 {
575 	struct xgene_clk *pclk = to_xgene_clk(hw);
576 	unsigned long flags = 0;
577 	u32 data;
578 	u32 divider;
579 	u32 divider_save;
580 
581 	if (pclk->lock)
582 		spin_lock_irqsave(pclk->lock, flags);
583 
584 	if (pclk->param.divider_reg) {
585 		/* Let's compute the divider */
586 		if (rate > parent_rate)
587 			rate = parent_rate;
588 		divider_save = divider = parent_rate / rate; /* Rounded down */
589 		divider &= (1 << pclk->param.reg_divider_width) - 1;
590 		divider <<= pclk->param.reg_divider_shift;
591 
592 		/* Set new divider */
593 		data = xgene_clk_read(pclk->param.divider_reg +
594 				pclk->param.reg_divider_offset);
595 		data &= ~(((1 << pclk->param.reg_divider_width) - 1)
596 				<< pclk->param.reg_divider_shift);
597 		data |= divider;
598 		xgene_clk_write(data, pclk->param.divider_reg +
599 					pclk->param.reg_divider_offset);
600 		pr_debug("%s clock set rate %ld\n", clk_hw_get_name(hw),
601 			parent_rate / divider_save);
602 	} else {
603 		divider_save = 1;
604 	}
605 
606 	if (pclk->lock)
607 		spin_unlock_irqrestore(pclk->lock, flags);
608 
609 	return parent_rate / divider_save;
610 }
611 
612 static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
613 				unsigned long *prate)
614 {
615 	struct xgene_clk *pclk = to_xgene_clk(hw);
616 	unsigned long parent_rate = *prate;
617 	u32 divider;
618 
619 	if (pclk->param.divider_reg) {
620 		/* Let's compute the divider */
621 		if (rate > parent_rate)
622 			rate = parent_rate;
623 		divider = parent_rate / rate;   /* Rounded down */
624 	} else {
625 		divider = 1;
626 	}
627 
628 	return parent_rate / divider;
629 }
630 
631 static const struct clk_ops xgene_clk_ops = {
632 	.enable = xgene_clk_enable,
633 	.disable = xgene_clk_disable,
634 	.is_enabled = xgene_clk_is_enabled,
635 	.recalc_rate = xgene_clk_recalc_rate,
636 	.set_rate = xgene_clk_set_rate,
637 	.round_rate = xgene_clk_round_rate,
638 };
639 
640 static struct clk *xgene_register_clk(struct device *dev,
641 		const char *name, const char *parent_name,
642 		struct xgene_dev_parameters *parameters, spinlock_t *lock)
643 {
644 	struct xgene_clk *apmclk;
645 	struct clk *clk;
646 	struct clk_init_data init;
647 	int rc;
648 
649 	/* allocate the APM clock structure */
650 	apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
651 	if (!apmclk)
652 		return ERR_PTR(-ENOMEM);
653 
654 	init.name = name;
655 	init.ops = &xgene_clk_ops;
656 	init.flags = 0;
657 	init.parent_names = parent_name ? &parent_name : NULL;
658 	init.num_parents = parent_name ? 1 : 0;
659 
660 	apmclk->lock = lock;
661 	apmclk->hw.init = &init;
662 	apmclk->param = *parameters;
663 
664 	/* Register the clock */
665 	clk = clk_register(dev, &apmclk->hw);
666 	if (IS_ERR(clk)) {
667 		pr_err("%s: could not register clk %s\n", __func__, name);
668 		kfree(apmclk);
669 		return clk;
670 	}
671 
672 	/* Register the clock for lookup */
673 	rc = clk_register_clkdev(clk, name, NULL);
674 	if (rc != 0) {
675 		pr_err("%s: could not register lookup clk %s\n",
676 			__func__, name);
677 	}
678 	return clk;
679 }
680 
681 static void __init xgene_devclk_init(struct device_node *np)
682 {
683 	const char *clk_name = np->full_name;
684 	struct clk *clk;
685 	struct resource res;
686 	int rc;
687 	struct xgene_dev_parameters parameters;
688 	int i;
689 
690 	/* Check if the entry is disabled */
691         if (!of_device_is_available(np))
692                 return;
693 
694 	/* Parse the DTS register for resource */
695 	parameters.csr_reg = NULL;
696 	parameters.divider_reg = NULL;
697 	for (i = 0; i < 2; i++) {
698 		void __iomem *map_res;
699 		rc = of_address_to_resource(np, i, &res);
700 		if (rc != 0) {
701 			if (i == 0) {
702 				pr_err("no DTS register for %pOF\n", np);
703 				return;
704 			}
705 			break;
706 		}
707 		map_res = of_iomap(np, i);
708 		if (!map_res) {
709 			pr_err("Unable to map resource %d for %pOF\n", i, np);
710 			goto err;
711 		}
712 		if (strcmp(res.name, "div-reg") == 0)
713 			parameters.divider_reg = map_res;
714 		else /* if (strcmp(res->name, "csr-reg") == 0) */
715 			parameters.csr_reg = map_res;
716 	}
717 	if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
718 		parameters.reg_csr_offset = 0;
719 	if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
720 		parameters.reg_csr_mask = 0xF;
721 	if (of_property_read_u32(np, "enable-offset",
722 				&parameters.reg_clk_offset))
723 		parameters.reg_clk_offset = 0x8;
724 	if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
725 		parameters.reg_clk_mask = 0xF;
726 	if (of_property_read_u32(np, "divider-offset",
727 				&parameters.reg_divider_offset))
728 		parameters.reg_divider_offset = 0;
729 	if (of_property_read_u32(np, "divider-width",
730 				&parameters.reg_divider_width))
731 		parameters.reg_divider_width = 0;
732 	if (of_property_read_u32(np, "divider-shift",
733 				&parameters.reg_divider_shift))
734 		parameters.reg_divider_shift = 0;
735 	of_property_read_string(np, "clock-output-names", &clk_name);
736 
737 	clk = xgene_register_clk(NULL, clk_name,
738 		of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
739 	if (IS_ERR(clk))
740 		goto err;
741 	pr_debug("Add %s clock\n", clk_name);
742 	rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
743 	if (rc != 0)
744 		pr_err("%s: could register provider clk %pOF\n", __func__, np);
745 
746 	return;
747 
748 err:
749 	if (parameters.csr_reg)
750 		iounmap(parameters.csr_reg);
751 	if (parameters.divider_reg)
752 		iounmap(parameters.divider_reg);
753 }
754 
755 CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
756 CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
757 CLK_OF_DECLARE(xgene_pmd_clock, "apm,xgene-pmd-clock", xgene_pmdclk_init);
758 CLK_OF_DECLARE(xgene_socpll_v2_clock, "apm,xgene-socpll-v2-clock",
759 	       xgene_socpllclk_init);
760 CLK_OF_DECLARE(xgene_pcppll_v2_clock, "apm,xgene-pcppll-v2-clock",
761 	       xgene_pcppllclk_init);
762 CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
763