1/*
2 * Copyright (C) 2013 DENX Software Engineering
3 *
4 * Gerhard Sittig, <gsi@denx.de>
5 *
6 * common clock driver support for the MPC512x platform
7 *
8 * This is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#include <linux/bitops.h>
15#include <linux/clk-provider.h>
16#include <linux/clkdev.h>
17#include <linux/device.h>
18#include <linux/errno.h>
19#include <linux/io.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22
23#include <asm/mpc5121.h>
24#include <dt-bindings/clock/mpc512x-clock.h>
25
26#include "mpc512x.h"		/* our public mpc5121_clk_init() API */
27
28/* helpers to keep the MCLK intermediates "somewhere" in our table */
29enum {
30	MCLK_IDX_MUX0,
31	MCLK_IDX_EN0,
32	MCLK_IDX_DIV0,
33	MCLK_MAX_IDX,
34};
35
36#define NR_PSCS			12
37#define NR_MSCANS		4
38#define NR_SPDIFS		1
39#define NR_OUTCLK		4
40#define NR_MCLKS		(NR_PSCS + NR_MSCANS + NR_SPDIFS + NR_OUTCLK)
41
42/* extend the public set of clocks by adding internal slots for management */
43enum {
44	/* arrange for adjacent numbers after the public set */
45	MPC512x_CLK_START_PRIVATE = MPC512x_CLK_LAST_PUBLIC,
46	/* clocks which aren't announced to the public */
47	MPC512x_CLK_DDR,
48	MPC512x_CLK_MEM,
49	MPC512x_CLK_IIM,
50	/* intermediates in div+gate combos or fractional dividers */
51	MPC512x_CLK_DDR_UG,
52	MPC512x_CLK_SDHC_x4,
53	MPC512x_CLK_SDHC_UG,
54	MPC512x_CLK_SDHC2_UG,
55	MPC512x_CLK_DIU_x4,
56	MPC512x_CLK_DIU_UG,
57	MPC512x_CLK_MBX_BUS_UG,
58	MPC512x_CLK_MBX_UG,
59	MPC512x_CLK_MBX_3D_UG,
60	MPC512x_CLK_PCI_UG,
61	MPC512x_CLK_NFC_UG,
62	MPC512x_CLK_LPC_UG,
63	MPC512x_CLK_SPDIF_TX_IN,
64	/* intermediates for the mux+gate+div+mux MCLK generation */
65	MPC512x_CLK_MCLKS_FIRST,
66	MPC512x_CLK_MCLKS_LAST = MPC512x_CLK_MCLKS_FIRST
67				+ NR_MCLKS * MCLK_MAX_IDX,
68	/* internal, symbolic spec for the number of slots */
69	MPC512x_CLK_LAST_PRIVATE,
70};
71
72/* data required for the OF clock provider registration */
73static struct clk *clks[MPC512x_CLK_LAST_PRIVATE];
74static struct clk_onecell_data clk_data;
75
76/* CCM register access */
77static struct mpc512x_ccm __iomem *clkregs;
78static DEFINE_SPINLOCK(clklock);
79
80/* SoC variants {{{ */
81
82/*
83 * tell SoC variants apart as they are rather similar yet not identical,
84 * cache the result in an enum to not repeatedly run the expensive OF test
85 *
86 * MPC5123 is an MPC5121 without the MBX graphics accelerator
87 *
88 * MPC5125 has many more differences: no MBX, no AXE, no VIU, no SPDIF,
89 * no PATA, no SATA, no PCI, two FECs (of different compatibility name),
90 * only 10 PSCs (of different compatibility name), two SDHCs, different
91 * NFC IP block, output clocks, system PLL status query, different CPMF
92 * interpretation, no CFM, different fourth PSC/CAN mux0 input -- yet
93 * those differences can get folded into this clock provider support
94 * code and don't warrant a separate highly redundant implementation
95 */
96
97static enum soc_type {
98	MPC512x_SOC_MPC5121,
99	MPC512x_SOC_MPC5123,
100	MPC512x_SOC_MPC5125,
101} soc;
102
103static void mpc512x_clk_determine_soc(void)
104{
105	if (of_machine_is_compatible("fsl,mpc5121")) {
106		soc = MPC512x_SOC_MPC5121;
107		return;
108	}
109	if (of_machine_is_compatible("fsl,mpc5123")) {
110		soc = MPC512x_SOC_MPC5123;
111		return;
112	}
113	if (of_machine_is_compatible("fsl,mpc5125")) {
114		soc = MPC512x_SOC_MPC5125;
115		return;
116	}
117}
118
119static bool soc_has_mbx(void)
120{
121	if (soc == MPC512x_SOC_MPC5121)
122		return true;
123	return false;
124}
125
126static bool soc_has_axe(void)
127{
128	if (soc == MPC512x_SOC_MPC5125)
129		return false;
130	return true;
131}
132
133static bool soc_has_viu(void)
134{
135	if (soc == MPC512x_SOC_MPC5125)
136		return false;
137	return true;
138}
139
140static bool soc_has_spdif(void)
141{
142	if (soc == MPC512x_SOC_MPC5125)
143		return false;
144	return true;
145}
146
147static bool soc_has_pata(void)
148{
149	if (soc == MPC512x_SOC_MPC5125)
150		return false;
151	return true;
152}
153
154static bool soc_has_sata(void)
155{
156	if (soc == MPC512x_SOC_MPC5125)
157		return false;
158	return true;
159}
160
161static bool soc_has_pci(void)
162{
163	if (soc == MPC512x_SOC_MPC5125)
164		return false;
165	return true;
166}
167
168static bool soc_has_fec2(void)
169{
170	if (soc == MPC512x_SOC_MPC5125)
171		return true;
172	return false;
173}
174
175static int soc_max_pscnum(void)
176{
177	if (soc == MPC512x_SOC_MPC5125)
178		return 10;
179	return 12;
180}
181
182static bool soc_has_sdhc2(void)
183{
184	if (soc == MPC512x_SOC_MPC5125)
185		return true;
186	return false;
187}
188
189static bool soc_has_nfc_5125(void)
190{
191	if (soc == MPC512x_SOC_MPC5125)
192		return true;
193	return false;
194}
195
196static bool soc_has_outclk(void)
197{
198	if (soc == MPC512x_SOC_MPC5125)
199		return true;
200	return false;
201}
202
203static bool soc_has_cpmf_0_bypass(void)
204{
205	if (soc == MPC512x_SOC_MPC5125)
206		return true;
207	return false;
208}
209
210static bool soc_has_mclk_mux0_canin(void)
211{
212	if (soc == MPC512x_SOC_MPC5125)
213		return true;
214	return false;
215}
216
217/* }}} SoC variants */
218/* common clk API wrappers {{{ */
219
220/* convenience wrappers around the common clk API */
221static inline struct clk *mpc512x_clk_fixed(const char *name, int rate)
222{
223	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);
224}
225
226static inline struct clk *mpc512x_clk_factor(
227	const char *name, const char *parent_name,
228	int mul, int div)
229{
230	int clkflags;
231
232	clkflags = CLK_SET_RATE_PARENT;
233	return clk_register_fixed_factor(NULL, name, parent_name, clkflags,
234					 mul, div);
235}
236
237static inline struct clk *mpc512x_clk_divider(
238	const char *name, const char *parent_name, u8 clkflags,
239	u32 __iomem *reg, u8 pos, u8 len, int divflags)
240{
241	return clk_register_divider(NULL, name, parent_name, clkflags,
242				    reg, pos, len, divflags, &clklock);
243}
244
245static inline struct clk *mpc512x_clk_divtable(
246	const char *name, const char *parent_name,
247	u32 __iomem *reg, u8 pos, u8 len,
248	const struct clk_div_table *divtab)
249{
250	u8 divflags;
251
252	divflags = 0;
253	return clk_register_divider_table(NULL, name, parent_name, 0,
254					  reg, pos, len, divflags,
255					  divtab, &clklock);
256}
257
258static inline struct clk *mpc512x_clk_gated(
259	const char *name, const char *parent_name,
260	u32 __iomem *reg, u8 pos)
261{
262	int clkflags;
263
264	clkflags = CLK_SET_RATE_PARENT;
265	return clk_register_gate(NULL, name, parent_name, clkflags,
266				 reg, pos, 0, &clklock);
267}
268
269static inline struct clk *mpc512x_clk_muxed(const char *name,
270	const char **parent_names, int parent_count,
271	u32 __iomem *reg, u8 pos, u8 len)
272{
273	int clkflags;
274	u8 muxflags;
275
276	clkflags = CLK_SET_RATE_PARENT;
277	muxflags = 0;
278	return clk_register_mux(NULL, name,
279				parent_names, parent_count, clkflags,
280				reg, pos, len, muxflags, &clklock);
281}
282
283/* }}} common clk API wrappers */
284
285/* helper to isolate a bit field from a register */
286static inline int get_bit_field(uint32_t __iomem *reg, uint8_t pos, uint8_t len)
287{
288	uint32_t val;
289
290	val = in_be32(reg);
291	val >>= pos;
292	val &= (1 << len) - 1;
293	return val;
294}
295
296/* get the SPMF and translate it into the "sys pll" multiplier */
297static int get_spmf_mult(void)
298{
299	static int spmf_to_mult[] = {
300		68, 1, 12, 16, 20, 24, 28, 32,
301		36, 40, 44, 48, 52, 56, 60, 64,
302	};
303	int spmf;
304
305	spmf = get_bit_field(&clkregs->spmr, 24, 4);
306	return spmf_to_mult[spmf];
307}
308
309/*
310 * get the SYS_DIV value and translate it into a divide factor
311 *
312 * values returned from here are a multiple of the real factor since the
313 * divide ratio is fractional
314 */
315static int get_sys_div_x2(void)
316{
317	static int sysdiv_code_to_x2[] = {
318		4, 5, 6, 7, 8, 9, 10, 14,
319		12, 16, 18, 22, 20, 24, 26, 30,
320		28, 32, 34, 38, 36, 40, 42, 46,
321		44, 48, 50, 54, 52, 56, 58, 62,
322		60, 64, 66,
323	};
324	int divcode;
325
326	divcode = get_bit_field(&clkregs->scfr2, 26, 6);
327	return sysdiv_code_to_x2[divcode];
328}
329
330/*
331 * get the CPMF value and translate it into a multiplier factor
332 *
333 * values returned from here are a multiple of the real factor since the
334 * multiplier ratio is fractional
335 */
336static int get_cpmf_mult_x2(void)
337{
338	static int cpmf_to_mult_x36[] = {
339		/* 0b000 is "times 36" */
340		72, 2, 2, 3, 4, 5, 6, 7,
341	};
342	static int cpmf_to_mult_0by[] = {
343		/* 0b000 is "bypass" */
344		2, 2, 2, 3, 4, 5, 6, 7,
345	};
346
347	int *cpmf_to_mult;
348	int cpmf;
349
350	cpmf = get_bit_field(&clkregs->spmr, 16, 4);
351	if (soc_has_cpmf_0_bypass())
352		cpmf_to_mult = cpmf_to_mult_0by;
353	else
354		cpmf_to_mult = cpmf_to_mult_x36;
355	return cpmf_to_mult[cpmf];
356}
357
358/*
359 * some of the clock dividers do scale in a linear way, yet not all of
360 * their bit combinations are legal; use a divider table to get a
361 * resulting set of applicable divider values
362 */
363
364/* applies to the IPS_DIV, and PCI_DIV values */
365static struct clk_div_table divtab_2346[] = {
366	{ .val = 2, .div = 2, },
367	{ .val = 3, .div = 3, },
368	{ .val = 4, .div = 4, },
369	{ .val = 6, .div = 6, },
370	{ .div = 0, },
371};
372
373/* applies to the MBX_DIV, LPC_DIV, and NFC_DIV values */
374static struct clk_div_table divtab_1234[] = {
375	{ .val = 1, .div = 1, },
376	{ .val = 2, .div = 2, },
377	{ .val = 3, .div = 3, },
378	{ .val = 4, .div = 4, },
379	{ .div = 0, },
380};
381
382static int get_freq_from_dt(char *propname)
383{
384	struct device_node *np;
385	const unsigned int *prop;
386	int val;
387
388	val = 0;
389	np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-immr");
390	if (np) {
391		prop = of_get_property(np, propname, NULL);
392		if (prop)
393			val = *prop;
394	    of_node_put(np);
395	}
396	return val;
397}
398
399static void mpc512x_clk_preset_data(void)
400{
401	size_t i;
402
403	for (i = 0; i < ARRAY_SIZE(clks); i++)
404		clks[i] = ERR_PTR(-ENODEV);
405}
406
407/*
408 * - receives the "bus frequency" from the caller (that's the IPS clock
409 *   rate, the historical source of clock information)
410 * - fetches the system PLL multiplier and divider values as well as the
411 *   IPS divider value from hardware
412 * - determines the REF clock rate either from the XTAL/OSC spec (if
413 *   there is a device tree node describing the oscillator) or from the
414 *   IPS bus clock (supported for backwards compatibility, such that
415 *   setups without XTAL/OSC specs keep working)
416 * - creates the "ref" clock item in the clock tree, such that
417 *   subsequent code can create the remainder of the hierarchy (REF ->
418 *   SYS -> CSB -> IPS) from the REF clock rate and the returned mul/div
419 *   values
420 */
421static void mpc512x_clk_setup_ref_clock(struct device_node *np, int bus_freq,
422					int *sys_mul, int *sys_div,
423					int *ips_div)
424{
425	struct clk *osc_clk;
426	int calc_freq;
427
428	/* fetch mul/div factors from the hardware */
429	*sys_mul = get_spmf_mult();
430	*sys_mul *= 2;		/* compensate for the fractional divider */
431	*sys_div = get_sys_div_x2();
432	*ips_div = get_bit_field(&clkregs->scfr1, 23, 3);
433
434	/* lookup the oscillator clock for its rate */
435	osc_clk = of_clk_get_by_name(np, "osc");
436
437	/*
438	 * either descend from OSC to REF (and in bypassing verify the
439	 * IPS rate), or backtrack from IPS and multiplier values that
440	 * were fetched from hardware to REF and thus to the OSC value
441	 *
442	 * in either case the REF clock gets created here and the
443	 * remainder of the clock tree can get spanned from there
444	 */
445	if (!IS_ERR(osc_clk)) {
446		clks[MPC512x_CLK_REF] = mpc512x_clk_factor("ref", "osc", 1, 1);
447		calc_freq = clk_get_rate(clks[MPC512x_CLK_REF]);
448		calc_freq *= *sys_mul;
449		calc_freq /= *sys_div;
450		calc_freq /= 2;
451		calc_freq /= *ips_div;
452		if (bus_freq && calc_freq != bus_freq)
453			pr_warn("calc rate %d != OF spec %d\n",
454				calc_freq, bus_freq);
455	} else {
456		calc_freq = bus_freq;	/* start with IPS */
457		calc_freq *= *ips_div;	/* IPS -> CSB */
458		calc_freq *= 2;		/* CSB -> SYS */
459		calc_freq *= *sys_div;	/* SYS -> PLL out */
460		calc_freq /= *sys_mul;	/* PLL out -> REF == OSC */
461		clks[MPC512x_CLK_REF] = mpc512x_clk_fixed("ref", calc_freq);
462	}
463}
464
465/* MCLK helpers {{{ */
466
467/*
468 * helper code for the MCLK subtree setup
469 *
470 * the overview in section 5.2.4 of the MPC5121e Reference Manual rev4
471 * suggests that all instances of the "PSC clock generation" are equal,
472 * and that one might re-use the PSC setup for MSCAN clock generation
473 * (section 5.2.5) as well, at least the logic if not the data for
474 * description
475 *
476 * the details (starting at page 5-20) show differences in the specific
477 * inputs of the first mux stage ("can clk in", "spdif tx"), and the
478 * factual non-availability of the second mux stage (it's present yet
479 * only one input is valid)
480 *
481 * the MSCAN clock related registers (starting at page 5-35) all
482 * reference "spdif clk" at the first mux stage and don't mention any
483 * "can clk" at all, which somehow is unexpected
484 *
485 * TODO re-check the document, and clarify whether the RM is correct in
486 * the overview or in the details, and whether the difference is a
487 * clipboard induced error or results from chip revisions
488 *
489 * it turns out that the RM rev4 as of 2012-06 talks about "can" for the
490 * PSCs while RM rev3 as of 2008-10 talks about "spdif", so I guess that
491 * first a doc update is required which better reflects reality in the
492 * SoC before the implementation should follow while no questions remain
493 */
494
495/*
496 * note that this declaration raises a checkpatch warning, but
497 * it's the very data type dictated by <linux/clk-provider.h>,
498 * "fixing" this warning will break compilation
499 */
500static const char *parent_names_mux0_spdif[] = {
501	"sys", "ref", "psc-mclk-in", "spdif-tx",
502};
503
504static const char *parent_names_mux0_canin[] = {
505	"sys", "ref", "psc-mclk-in", "can-clk-in",
506};
507
508enum mclk_type {
509	MCLK_TYPE_PSC,
510	MCLK_TYPE_MSCAN,
511	MCLK_TYPE_SPDIF,
512	MCLK_TYPE_OUTCLK,
513};
514
515struct mclk_setup_data {
516	enum mclk_type type;
517	bool has_mclk1;
518	const char *name_mux0;
519	const char *name_en0;
520	const char *name_div0;
521	const char *parent_names_mux1[2];
522	const char *name_mclk;
523};
524
525#define MCLK_SETUP_DATA_PSC(id) { \
526	MCLK_TYPE_PSC, 0, \
527	"psc" #id "-mux0", \
528	"psc" #id "-en0", \
529	"psc" #id "_mclk_div", \
530	{ "psc" #id "_mclk_div", "dummy", }, \
531	"psc" #id "_mclk", \
532}
533
534#define MCLK_SETUP_DATA_MSCAN(id) { \
535	MCLK_TYPE_MSCAN, 0, \
536	"mscan" #id "-mux0", \
537	"mscan" #id "-en0", \
538	"mscan" #id "_mclk_div", \
539	{ "mscan" #id "_mclk_div", "dummy", }, \
540	"mscan" #id "_mclk", \
541}
542
543#define MCLK_SETUP_DATA_SPDIF { \
544	MCLK_TYPE_SPDIF, 1, \
545	"spdif-mux0", \
546	"spdif-en0", \
547	"spdif_mclk_div", \
548	{ "spdif_mclk_div", "spdif-rx", }, \
549	"spdif_mclk", \
550}
551
552#define MCLK_SETUP_DATA_OUTCLK(id) { \
553	MCLK_TYPE_OUTCLK, 0, \
554	"out" #id "-mux0", \
555	"out" #id "-en0", \
556	"out" #id "_mclk_div", \
557	{ "out" #id "_mclk_div", "dummy", }, \
558	"out" #id "_clk", \
559}
560
561static struct mclk_setup_data mclk_psc_data[] = {
562	MCLK_SETUP_DATA_PSC(0),
563	MCLK_SETUP_DATA_PSC(1),
564	MCLK_SETUP_DATA_PSC(2),
565	MCLK_SETUP_DATA_PSC(3),
566	MCLK_SETUP_DATA_PSC(4),
567	MCLK_SETUP_DATA_PSC(5),
568	MCLK_SETUP_DATA_PSC(6),
569	MCLK_SETUP_DATA_PSC(7),
570	MCLK_SETUP_DATA_PSC(8),
571	MCLK_SETUP_DATA_PSC(9),
572	MCLK_SETUP_DATA_PSC(10),
573	MCLK_SETUP_DATA_PSC(11),
574};
575
576static struct mclk_setup_data mclk_mscan_data[] = {
577	MCLK_SETUP_DATA_MSCAN(0),
578	MCLK_SETUP_DATA_MSCAN(1),
579	MCLK_SETUP_DATA_MSCAN(2),
580	MCLK_SETUP_DATA_MSCAN(3),
581};
582
583static struct mclk_setup_data mclk_spdif_data[] = {
584	MCLK_SETUP_DATA_SPDIF,
585};
586
587static struct mclk_setup_data mclk_outclk_data[] = {
588	MCLK_SETUP_DATA_OUTCLK(0),
589	MCLK_SETUP_DATA_OUTCLK(1),
590	MCLK_SETUP_DATA_OUTCLK(2),
591	MCLK_SETUP_DATA_OUTCLK(3),
592};
593
594/* setup the MCLK clock subtree of an individual PSC/MSCAN/SPDIF */
595static void mpc512x_clk_setup_mclk(struct mclk_setup_data *entry, size_t idx)
596{
597	size_t clks_idx_pub, clks_idx_int;
598	u32 __iomem *mccr_reg;	/* MCLK control register (mux, en, div) */
599	int div;
600
601	/* derive a few parameters from the component type and index */
602	switch (entry->type) {
603	case MCLK_TYPE_PSC:
604		clks_idx_pub = MPC512x_CLK_PSC0_MCLK + idx;
605		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
606			     + (idx) * MCLK_MAX_IDX;
607		mccr_reg = &clkregs->psc_ccr[idx];
608		break;
609	case MCLK_TYPE_MSCAN:
610		clks_idx_pub = MPC512x_CLK_MSCAN0_MCLK + idx;
611		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
612			     + (NR_PSCS + idx) * MCLK_MAX_IDX;
613		mccr_reg = &clkregs->mscan_ccr[idx];
614		break;
615	case MCLK_TYPE_SPDIF:
616		clks_idx_pub = MPC512x_CLK_SPDIF_MCLK;
617		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
618			     + (NR_PSCS + NR_MSCANS) * MCLK_MAX_IDX;
619		mccr_reg = &clkregs->spccr;
620		break;
621	case MCLK_TYPE_OUTCLK:
622		clks_idx_pub = MPC512x_CLK_OUT0_CLK + idx;
623		clks_idx_int = MPC512x_CLK_MCLKS_FIRST
624			     + (NR_PSCS + NR_MSCANS + NR_SPDIFS + idx)
625			     * MCLK_MAX_IDX;
626		mccr_reg = &clkregs->out_ccr[idx];
627		break;
628	default:
629		return;
630	}
631
632	/*
633	 * this was grabbed from the PPC_CLOCK implementation, which
634	 * enforced a specific MCLK divider while the clock was gated
635	 * during setup (that's a documented hardware requirement)
636	 *
637	 * the PPC_CLOCK implementation might even have violated the
638	 * "MCLK <= IPS" constraint, the fixed divider value of 1
639	 * results in a divider of 2 and thus MCLK = SYS/2 which equals
640	 * CSB which is greater than IPS; the serial port setup may have
641	 * adjusted the divider which the clock setup might have left in
642	 * an undesirable state
643	 *
644	 * initial setup is:
645	 * - MCLK 0 from SYS
646	 * - MCLK DIV such to not exceed the IPS clock
647	 * - MCLK 0 enabled
648	 * - MCLK 1 from MCLK DIV
649	 */
650	div = clk_get_rate(clks[MPC512x_CLK_SYS]);
651	div /= clk_get_rate(clks[MPC512x_CLK_IPS]);
652	out_be32(mccr_reg, (0 << 16));
653	out_be32(mccr_reg, (0 << 16) | ((div - 1) << 17));
654	out_be32(mccr_reg, (1 << 16) | ((div - 1) << 17));
655
656	/*
657	 * create the 'struct clk' items of the MCLK's clock subtree
658	 *
659	 * note that by design we always create all nodes and won't take
660	 * shortcuts here, because
661	 * - the "internal" MCLK_DIV and MCLK_OUT signal in turn are
662	 *   selectable inputs to the CFM while those who "actually use"
663	 *   the PSC/MSCAN/SPDIF (serial drivers et al) need the MCLK
664	 *   for their bitrate
665	 * - in the absence of "aliases" for clocks we need to create
666	 *   individial 'struct clk' items for whatever might get
667	 *   referenced or looked up, even if several of those items are
668	 *   identical from the logical POV (their rate value)
669	 * - for easier future maintenance and for better reflection of
670	 *   the SoC's documentation, it appears appropriate to generate
671	 *   clock items even for those muxers which actually are NOPs
672	 *   (those with two inputs of which one is reserved)
673	 */
674	clks[clks_idx_int + MCLK_IDX_MUX0] = mpc512x_clk_muxed(
675			entry->name_mux0,
676			soc_has_mclk_mux0_canin()
677				? &parent_names_mux0_canin[0]
678				: &parent_names_mux0_spdif[0],
679			ARRAY_SIZE(parent_names_mux0_spdif),
680			mccr_reg, 14, 2);
681	clks[clks_idx_int + MCLK_IDX_EN0] = mpc512x_clk_gated(
682			entry->name_en0, entry->name_mux0,
683			mccr_reg, 16);
684	clks[clks_idx_int + MCLK_IDX_DIV0] = mpc512x_clk_divider(
685			entry->name_div0,
686			entry->name_en0, CLK_SET_RATE_GATE,
687			mccr_reg, 17, 15, 0);
688	if (entry->has_mclk1) {
689		clks[clks_idx_pub] = mpc512x_clk_muxed(
690				entry->name_mclk,
691				&entry->parent_names_mux1[0],
692				ARRAY_SIZE(entry->parent_names_mux1),
693				mccr_reg, 7, 1);
694	} else {
695		clks[clks_idx_pub] = mpc512x_clk_factor(
696				entry->name_mclk,
697				entry->parent_names_mux1[0],
698				1, 1);
699	}
700}
701
702/* }}} MCLK helpers */
703
704static void mpc512x_clk_setup_clock_tree(struct device_node *np, int busfreq)
705{
706	int sys_mul, sys_div, ips_div;
707	int mul, div;
708	size_t mclk_idx;
709	int freq;
710
711	/*
712	 * developer's notes:
713	 * - consider whether to handle clocks which have both gates and
714	 *   dividers via intermediates or by means of composites
715	 * - fractional dividers appear to not map well to composites
716	 *   since they can be seen as a fixed multiplier and an
717	 *   adjustable divider, while composites can only combine at
718	 *   most one of a mux, div, and gate each into one 'struct clk'
719	 *   item
720	 * - PSC/MSCAN/SPDIF clock generation OTOH already is very
721	 *   specific and cannot get mapped to componsites (at least not
722	 *   a single one, maybe two of them, but then some of these
723	 *   intermediate clock signals get referenced elsewhere (e.g.
724	 *   in the clock frequency measurement, CFM) and thus need
725	 *   publicly available names
726	 * - the current source layout appropriately reflects the
727	 *   hardware setup, and it works, so it's questionable whether
728	 *   further changes will result in big enough a benefit
729	 */
730
731	/* regardless of whether XTAL/OSC exists, have REF created */
732	mpc512x_clk_setup_ref_clock(np, busfreq, &sys_mul, &sys_div, &ips_div);
733
734	/* now setup the REF -> SYS -> CSB -> IPS hierarchy */
735	clks[MPC512x_CLK_SYS] = mpc512x_clk_factor("sys", "ref",
736						   sys_mul, sys_div);
737	clks[MPC512x_CLK_CSB] = mpc512x_clk_factor("csb", "sys", 1, 2);
738	clks[MPC512x_CLK_IPS] = mpc512x_clk_divtable("ips", "csb",
739						     &clkregs->scfr1, 23, 3,
740						     divtab_2346);
741	/* now setup anything below SYS and CSB and IPS */
742
743	clks[MPC512x_CLK_DDR_UG] = mpc512x_clk_factor("ddr-ug", "sys", 1, 2);
744
745	/*
746	 * the Reference Manual discusses that for SDHC only even divide
747	 * ratios are supported because clock domain synchronization
748	 * between 'per' and 'ipg' is broken;
749	 * keep the divider's bit 0 cleared (per reset value), and only
750	 * allow to setup the divider's bits 7:1, which results in that
751	 * only even divide ratios can get configured upon rate changes;
752	 * keep the "x4" name because this bit shift hack is an internal
753	 * implementation detail, the "fractional divider with quarters"
754	 * semantics remains
755	 */
756	clks[MPC512x_CLK_SDHC_x4] = mpc512x_clk_factor("sdhc-x4", "csb", 2, 1);
757	clks[MPC512x_CLK_SDHC_UG] = mpc512x_clk_divider("sdhc-ug", "sdhc-x4", 0,
758							&clkregs->scfr2, 1, 7,
759							CLK_DIVIDER_ONE_BASED);
760	if (soc_has_sdhc2()) {
761		clks[MPC512x_CLK_SDHC2_UG] = mpc512x_clk_divider(
762				"sdhc2-ug", "sdhc-x4", 0, &clkregs->scfr2,
763				9, 7, CLK_DIVIDER_ONE_BASED);
764	}
765
766	clks[MPC512x_CLK_DIU_x4] = mpc512x_clk_factor("diu-x4", "csb", 4, 1);
767	clks[MPC512x_CLK_DIU_UG] = mpc512x_clk_divider("diu-ug", "diu-x4", 0,
768						       &clkregs->scfr1, 0, 8,
769						       CLK_DIVIDER_ONE_BASED);
770
771	/*
772	 * the "power architecture PLL" was setup from data which was
773	 * sampled from the reset config word, at this point in time the
774	 * configuration can be considered fixed and read only (i.e. no
775	 * longer adjustable, or no longer in need of adjustment), which
776	 * is why we don't register a PLL here but assume fixed factors
777	 */
778	mul = get_cpmf_mult_x2();
779	div = 2;	/* compensate for the fractional factor */
780	clks[MPC512x_CLK_E300] = mpc512x_clk_factor("e300", "csb", mul, div);
781
782	if (soc_has_mbx()) {
783		clks[MPC512x_CLK_MBX_BUS_UG] = mpc512x_clk_factor(
784				"mbx-bus-ug", "csb", 1, 2);
785		clks[MPC512x_CLK_MBX_UG] = mpc512x_clk_divtable(
786				"mbx-ug", "mbx-bus-ug", &clkregs->scfr1,
787				14, 3, divtab_1234);
788		clks[MPC512x_CLK_MBX_3D_UG] = mpc512x_clk_factor(
789				"mbx-3d-ug", "mbx-ug", 1, 1);
790	}
791	if (soc_has_pci()) {
792		clks[MPC512x_CLK_PCI_UG] = mpc512x_clk_divtable(
793				"pci-ug", "csb", &clkregs->scfr1,
794				20, 3, divtab_2346);
795	}
796	if (soc_has_nfc_5125()) {
797		/*
798		 * XXX TODO implement 5125 NFC clock setup logic,
799		 * with high/low period counters in clkregs->scfr3,
800		 * currently there are no users so it's ENOIMPL
801		 */
802		clks[MPC512x_CLK_NFC_UG] = ERR_PTR(-ENOTSUPP);
803	} else {
804		clks[MPC512x_CLK_NFC_UG] = mpc512x_clk_divtable(
805				"nfc-ug", "ips", &clkregs->scfr1,
806				8, 3, divtab_1234);
807	}
808	clks[MPC512x_CLK_LPC_UG] = mpc512x_clk_divtable("lpc-ug", "ips",
809							&clkregs->scfr1, 11, 3,
810							divtab_1234);
811
812	clks[MPC512x_CLK_LPC] = mpc512x_clk_gated("lpc", "lpc-ug",
813						  &clkregs->sccr1, 30);
814	clks[MPC512x_CLK_NFC] = mpc512x_clk_gated("nfc", "nfc-ug",
815						  &clkregs->sccr1, 29);
816	if (soc_has_pata()) {
817		clks[MPC512x_CLK_PATA] = mpc512x_clk_gated(
818				"pata", "ips", &clkregs->sccr1, 28);
819	}
820	/* for PSCs there is a "registers" gate and a bitrate MCLK subtree */
821	for (mclk_idx = 0; mclk_idx < soc_max_pscnum(); mclk_idx++) {
822		char name[12];
823		snprintf(name, sizeof(name), "psc%d", mclk_idx);
824		clks[MPC512x_CLK_PSC0 + mclk_idx] = mpc512x_clk_gated(
825				name, "ips", &clkregs->sccr1, 27 - mclk_idx);
826		mpc512x_clk_setup_mclk(&mclk_psc_data[mclk_idx], mclk_idx);
827	}
828	clks[MPC512x_CLK_PSC_FIFO] = mpc512x_clk_gated("psc-fifo", "ips",
829						       &clkregs->sccr1, 15);
830	if (soc_has_sata()) {
831		clks[MPC512x_CLK_SATA] = mpc512x_clk_gated(
832				"sata", "ips", &clkregs->sccr1, 14);
833	}
834	clks[MPC512x_CLK_FEC] = mpc512x_clk_gated("fec", "ips",
835						  &clkregs->sccr1, 13);
836	if (soc_has_pci()) {
837		clks[MPC512x_CLK_PCI] = mpc512x_clk_gated(
838				"pci", "pci-ug", &clkregs->sccr1, 11);
839	}
840	clks[MPC512x_CLK_DDR] = mpc512x_clk_gated("ddr", "ddr-ug",
841						  &clkregs->sccr1, 10);
842	if (soc_has_fec2()) {
843		clks[MPC512x_CLK_FEC2] = mpc512x_clk_gated(
844				"fec2", "ips", &clkregs->sccr1, 9);
845	}
846
847	clks[MPC512x_CLK_DIU] = mpc512x_clk_gated("diu", "diu-ug",
848						  &clkregs->sccr2, 31);
849	if (soc_has_axe()) {
850		clks[MPC512x_CLK_AXE] = mpc512x_clk_gated(
851				"axe", "csb", &clkregs->sccr2, 30);
852	}
853	clks[MPC512x_CLK_MEM] = mpc512x_clk_gated("mem", "ips",
854						  &clkregs->sccr2, 29);
855	clks[MPC512x_CLK_USB1] = mpc512x_clk_gated("usb1", "csb",
856						   &clkregs->sccr2, 28);
857	clks[MPC512x_CLK_USB2] = mpc512x_clk_gated("usb2", "csb",
858						   &clkregs->sccr2, 27);
859	clks[MPC512x_CLK_I2C] = mpc512x_clk_gated("i2c", "ips",
860						  &clkregs->sccr2, 26);
861	/* MSCAN differs from PSC with just one gate for multiple components */
862	clks[MPC512x_CLK_BDLC] = mpc512x_clk_gated("bdlc", "ips",
863						   &clkregs->sccr2, 25);
864	for (mclk_idx = 0; mclk_idx < ARRAY_SIZE(mclk_mscan_data); mclk_idx++)
865		mpc512x_clk_setup_mclk(&mclk_mscan_data[mclk_idx], mclk_idx);
866	clks[MPC512x_CLK_SDHC] = mpc512x_clk_gated("sdhc", "sdhc-ug",
867						   &clkregs->sccr2, 24);
868	/* there is only one SPDIF component, which shares MCLK support code */
869	if (soc_has_spdif()) {
870		clks[MPC512x_CLK_SPDIF] = mpc512x_clk_gated(
871				"spdif", "ips", &clkregs->sccr2, 23);
872		mpc512x_clk_setup_mclk(&mclk_spdif_data[0], 0);
873	}
874	if (soc_has_mbx()) {
875		clks[MPC512x_CLK_MBX_BUS] = mpc512x_clk_gated(
876				"mbx-bus", "mbx-bus-ug", &clkregs->sccr2, 22);
877		clks[MPC512x_CLK_MBX] = mpc512x_clk_gated(
878				"mbx", "mbx-ug", &clkregs->sccr2, 21);
879		clks[MPC512x_CLK_MBX_3D] = mpc512x_clk_gated(
880				"mbx-3d", "mbx-3d-ug", &clkregs->sccr2, 20);
881	}
882	clks[MPC512x_CLK_IIM] = mpc512x_clk_gated("iim", "csb",
883						  &clkregs->sccr2, 19);
884	if (soc_has_viu()) {
885		clks[MPC512x_CLK_VIU] = mpc512x_clk_gated(
886				"viu", "csb", &clkregs->sccr2, 18);
887	}
888	if (soc_has_sdhc2()) {
889		clks[MPC512x_CLK_SDHC2] = mpc512x_clk_gated(
890				"sdhc-2", "sdhc2-ug", &clkregs->sccr2, 17);
891	}
892
893	if (soc_has_outclk()) {
894		size_t idx;	/* used as mclk_idx, just to trim line length */
895		for (idx = 0; idx < ARRAY_SIZE(mclk_outclk_data); idx++)
896			mpc512x_clk_setup_mclk(&mclk_outclk_data[idx], idx);
897	}
898
899	/*
900	 * externally provided clocks (when implemented in hardware,
901	 * device tree may specify values which otherwise were unknown)
902	 */
903	freq = get_freq_from_dt("psc_mclk_in");
904	if (!freq)
905		freq = 25000000;
906	clks[MPC512x_CLK_PSC_MCLK_IN] = mpc512x_clk_fixed("psc_mclk_in", freq);
907	if (soc_has_mclk_mux0_canin()) {
908		freq = get_freq_from_dt("can_clk_in");
909		clks[MPC512x_CLK_CAN_CLK_IN] = mpc512x_clk_fixed(
910				"can_clk_in", freq);
911	} else {
912		freq = get_freq_from_dt("spdif_tx_in");
913		clks[MPC512x_CLK_SPDIF_TX_IN] = mpc512x_clk_fixed(
914				"spdif_tx_in", freq);
915		freq = get_freq_from_dt("spdif_rx_in");
916		clks[MPC512x_CLK_SPDIF_TX_IN] = mpc512x_clk_fixed(
917				"spdif_rx_in", freq);
918	}
919
920	/* fixed frequency for AC97, always 24.567MHz */
921	clks[MPC512x_CLK_AC97] = mpc512x_clk_fixed("ac97", 24567000);
922
923	/*
924	 * pre-enable those "internal" clock items which never get
925	 * claimed by any peripheral driver, to not have the clock
926	 * subsystem disable them late at startup
927	 */
928	clk_prepare_enable(clks[MPC512x_CLK_DUMMY]);
929	clk_prepare_enable(clks[MPC512x_CLK_E300]);	/* PowerPC CPU */
930	clk_prepare_enable(clks[MPC512x_CLK_DDR]);	/* DRAM */
931	clk_prepare_enable(clks[MPC512x_CLK_MEM]);	/* SRAM */
932	clk_prepare_enable(clks[MPC512x_CLK_IPS]);	/* SoC periph */
933	clk_prepare_enable(clks[MPC512x_CLK_LPC]);	/* boot media */
934}
935
936/*
937 * registers the set of public clocks (those listed in the dt-bindings/
938 * header file) for OF lookups, keeps the intermediates private to us
939 */
940static void mpc5121_clk_register_of_provider(struct device_node *np)
941{
942	clk_data.clks = clks;
943	clk_data.clk_num = MPC512x_CLK_LAST_PUBLIC + 1;	/* _not_ ARRAY_SIZE() */
944	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
945}
946
947/*
948 * temporary support for the period of time between introduction of CCF
949 * support and the adjustment of peripheral drivers to OF based lookups
950 */
951static void mpc5121_clk_provide_migration_support(void)
952{
953
954	/*
955	 * pre-enable those clock items which are not yet appropriately
956	 * acquired by their peripheral driver
957	 *
958	 * the PCI clock cannot get acquired by its peripheral driver,
959	 * because for this platform the driver won't probe(), instead
960	 * initialization is done from within the .setup_arch() routine
961	 * at a point in time where the clock provider has not been
962	 * setup yet and thus isn't available yet
963	 *
964	 * so we "pre-enable" the clock here, to not have the clock
965	 * subsystem automatically disable this item in a late init call
966	 *
967	 * this PCI clock pre-enable workaround only applies when there
968	 * are device tree nodes for PCI and thus the peripheral driver
969	 * has attached to bridges, otherwise the PCI clock remains
970	 * unused and so it gets disabled
971	 */
972	clk_prepare_enable(clks[MPC512x_CLK_PSC3_MCLK]);/* serial console */
973	if (of_find_compatible_node(NULL, "pci", "fsl,mpc5121-pci"))
974		clk_prepare_enable(clks[MPC512x_CLK_PCI]);
975}
976
977/*
978 * those macros are not exactly pretty, but they encapsulate a lot
979 * of copy'n'paste heavy code which is even more ugly, and reduce
980 * the potential for inconsistencies in those many code copies
981 */
982#define FOR_NODES(compatname) \
983	for_each_compatible_node(np, NULL, compatname)
984
985#define NODE_PREP do { \
986	of_address_to_resource(np, 0, &res); \
987	snprintf(devname, sizeof(devname), "%08x.%s", res.start, np->name); \
988} while (0)
989
990#define NODE_CHK(clkname, clkitem, regnode, regflag) do { \
991	struct clk *clk; \
992	clk = of_clk_get_by_name(np, clkname); \
993	if (IS_ERR(clk)) { \
994		clk = clkitem; \
995		clk_register_clkdev(clk, clkname, devname); \
996		if (regnode) \
997			clk_register_clkdev(clk, clkname, np->name); \
998		did_register |= DID_REG_ ## regflag; \
999		pr_debug("clock alias name '%s' for dev '%s' pointer %p\n", \
1000			 clkname, devname, clk); \
1001	} else { \
1002		clk_put(clk); \
1003	} \
1004} while (0)
1005
1006/*
1007 * register source code provided fallback results for clock lookups,
1008 * these get consulted when OF based clock lookup fails (that is in the
1009 * case of not yet adjusted device tree data, where clock related specs
1010 * are missing)
1011 */
1012static void mpc5121_clk_provide_backwards_compat(void)
1013{
1014	enum did_reg_flags {
1015		DID_REG_PSC	= BIT(0),
1016		DID_REG_PSCFIFO	= BIT(1),
1017		DID_REG_NFC	= BIT(2),
1018		DID_REG_CAN	= BIT(3),
1019		DID_REG_I2C	= BIT(4),
1020		DID_REG_DIU	= BIT(5),
1021		DID_REG_VIU	= BIT(6),
1022		DID_REG_FEC	= BIT(7),
1023		DID_REG_USB	= BIT(8),
1024		DID_REG_PATA	= BIT(9),
1025	};
1026
1027	int did_register;
1028	struct device_node *np;
1029	struct resource res;
1030	int idx;
1031	char devname[32];
1032
1033	did_register = 0;
1034
1035	FOR_NODES(mpc512x_select_psc_compat()) {
1036		NODE_PREP;
1037		idx = (res.start >> 8) & 0xf;
1038		NODE_CHK("ipg", clks[MPC512x_CLK_PSC0 + idx], 0, PSC);
1039		NODE_CHK("mclk", clks[MPC512x_CLK_PSC0_MCLK + idx], 0, PSC);
1040	}
1041
1042	FOR_NODES("fsl,mpc5121-psc-fifo") {
1043		NODE_PREP;
1044		NODE_CHK("ipg", clks[MPC512x_CLK_PSC_FIFO], 1, PSCFIFO);
1045	}
1046
1047	FOR_NODES("fsl,mpc5121-nfc") {
1048		NODE_PREP;
1049		NODE_CHK("ipg", clks[MPC512x_CLK_NFC], 0, NFC);
1050	}
1051
1052	FOR_NODES("fsl,mpc5121-mscan") {
1053		NODE_PREP;
1054		idx = 0;
1055		idx += (res.start & 0x2000) ? 2 : 0;
1056		idx += (res.start & 0x0080) ? 1 : 0;
1057		NODE_CHK("ipg", clks[MPC512x_CLK_BDLC], 0, CAN);
1058		NODE_CHK("mclk", clks[MPC512x_CLK_MSCAN0_MCLK + idx], 0, CAN);
1059	}
1060
1061	/*
1062	 * do register the 'ips', 'sys', and 'ref' names globally
1063	 * instead of inside each individual CAN node, as there is no
1064	 * potential for a name conflict (in contrast to 'ipg' and 'mclk')
1065	 */
1066	if (did_register & DID_REG_CAN) {
1067		clk_register_clkdev(clks[MPC512x_CLK_IPS], "ips", NULL);
1068		clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys", NULL);
1069		clk_register_clkdev(clks[MPC512x_CLK_REF], "ref", NULL);
1070	}
1071
1072	FOR_NODES("fsl,mpc5121-i2c") {
1073		NODE_PREP;
1074		NODE_CHK("ipg", clks[MPC512x_CLK_I2C], 0, I2C);
1075	}
1076
1077	/*
1078	 * workaround for the fact that the I2C driver does an "anonymous"
1079	 * lookup (NULL name spec, which yields the first clock spec) for
1080	 * which we cannot register an alias -- a _global_ 'ipg' alias that
1081	 * is not bound to any device name and returns the I2C clock item
1082	 * is not a good idea
1083	 *
1084	 * so we have the lookup in the peripheral driver fail, which is
1085	 * silent and non-fatal, and pre-enable the clock item here such
1086	 * that register access is possible
1087	 *
1088	 * see commit b3bfce2b "i2c: mpc: cleanup clock API use" for
1089	 * details, adjusting s/NULL/"ipg"/ in i2c-mpc.c would make this
1090	 * workaround obsolete
1091	 */
1092	if (did_register & DID_REG_I2C)
1093		clk_prepare_enable(clks[MPC512x_CLK_I2C]);
1094
1095	FOR_NODES("fsl,mpc5121-diu") {
1096		NODE_PREP;
1097		NODE_CHK("ipg", clks[MPC512x_CLK_DIU], 1, DIU);
1098	}
1099
1100	FOR_NODES("fsl,mpc5121-viu") {
1101		NODE_PREP;
1102		NODE_CHK("ipg", clks[MPC512x_CLK_VIU], 0, VIU);
1103	}
1104
1105	/*
1106	 * note that 2771399a "fs_enet: cleanup clock API use" did use the
1107	 * "per" string for the clock lookup in contrast to the "ipg" name
1108	 * which most other nodes are using -- this is not a fatal thing
1109	 * but just something to keep in mind when doing compatibility
1110	 * registration, it's a non-issue with up-to-date device tree data
1111	 */
1112	FOR_NODES("fsl,mpc5121-fec") {
1113		NODE_PREP;
1114		NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
1115	}
1116	FOR_NODES("fsl,mpc5121-fec-mdio") {
1117		NODE_PREP;
1118		NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
1119	}
1120	/*
1121	 * MPC5125 has two FECs: FEC1 at 0x2800, FEC2 at 0x4800;
1122	 * the clock items don't "form an array" since FEC2 was
1123	 * added only later and was not allowed to shift all other
1124	 * clock item indices, so the numbers aren't adjacent
1125	 */
1126	FOR_NODES("fsl,mpc5125-fec") {
1127		NODE_PREP;
1128		if (res.start & 0x4000)
1129			idx = MPC512x_CLK_FEC2;
1130		else
1131			idx = MPC512x_CLK_FEC;
1132		NODE_CHK("per", clks[idx], 0, FEC);
1133	}
1134
1135	FOR_NODES("fsl,mpc5121-usb2-dr") {
1136		NODE_PREP;
1137		idx = (res.start & 0x4000) ? 1 : 0;
1138		NODE_CHK("ipg", clks[MPC512x_CLK_USB1 + idx], 0, USB);
1139	}
1140
1141	FOR_NODES("fsl,mpc5121-pata") {
1142		NODE_PREP;
1143		NODE_CHK("ipg", clks[MPC512x_CLK_PATA], 0, PATA);
1144	}
1145
1146	/*
1147	 * try to collapse diagnostics into a single line of output yet
1148	 * provide a full list of what is missing, to avoid noise in the
1149	 * absence of up-to-date device tree data -- backwards
1150	 * compatibility to old DTBs is a requirement, updates may be
1151	 * desirable or preferrable but are not at all mandatory
1152	 */
1153	if (did_register) {
1154		pr_notice("device tree lacks clock specs, adding fallbacks (0x%x,%s%s%s%s%s%s%s%s%s%s)\n",
1155			  did_register,
1156			  (did_register & DID_REG_PSC) ? " PSC" : "",
1157			  (did_register & DID_REG_PSCFIFO) ? " PSCFIFO" : "",
1158			  (did_register & DID_REG_NFC) ? " NFC" : "",
1159			  (did_register & DID_REG_CAN) ? " CAN" : "",
1160			  (did_register & DID_REG_I2C) ? " I2C" : "",
1161			  (did_register & DID_REG_DIU) ? " DIU" : "",
1162			  (did_register & DID_REG_VIU) ? " VIU" : "",
1163			  (did_register & DID_REG_FEC) ? " FEC" : "",
1164			  (did_register & DID_REG_USB) ? " USB" : "",
1165			  (did_register & DID_REG_PATA) ? " PATA" : "");
1166	} else {
1167		pr_debug("device tree has clock specs, no fallbacks added\n");
1168	}
1169}
1170
1171/*
1172 * The "fixed-clock" nodes (which includes the oscillator node if the board's
1173 * DT provides one) has already been scanned by the of_clk_init() in
1174 * time_init().
1175 */
1176int __init mpc5121_clk_init(void)
1177{
1178	struct device_node *clk_np;
1179	int busfreq;
1180
1181	/* map the clock control registers */
1182	clk_np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
1183	if (!clk_np)
1184		return -ENODEV;
1185	clkregs = of_iomap(clk_np, 0);
1186	WARN_ON(!clkregs);
1187
1188	/* determine the SoC variant we run on */
1189	mpc512x_clk_determine_soc();
1190
1191	/* invalidate all not yet registered clock slots */
1192	mpc512x_clk_preset_data();
1193
1194	/*
1195	 * add a dummy clock for those situations where a clock spec is
1196	 * required yet no real clock is involved
1197	 */
1198	clks[MPC512x_CLK_DUMMY] = mpc512x_clk_fixed("dummy", 0);
1199
1200	/*
1201	 * have all the real nodes in the clock tree populated from REF
1202	 * down to all leaves, either starting from the OSC node or from
1203	 * a REF root that was created from the IPS bus clock input
1204	 */
1205	busfreq = get_freq_from_dt("bus-frequency");
1206	mpc512x_clk_setup_clock_tree(clk_np, busfreq);
1207
1208	/* register as an OF clock provider */
1209	mpc5121_clk_register_of_provider(clk_np);
1210
1211	/*
1212	 * unbreak not yet adjusted peripheral drivers during migration
1213	 * towards fully operational common clock support, and allow
1214	 * operation in the absence of clock related device tree specs
1215	 */
1216	mpc5121_clk_provide_migration_support();
1217	mpc5121_clk_provide_backwards_compat();
1218
1219	return 0;
1220}
1221