1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2013 DENX Software Engineering
4 *
5 * Gerhard Sittig, <gsi@denx.de>
6 *
7 * common clock driver support for the MPC512x platform
8 */
9
10 #include <linux/bitops.h>
11 #include <linux/clk.h>
12 #include <linux/clk-provider.h>
13 #include <linux/clkdev.h>
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/io.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19
20 #include <asm/mpc5121.h>
21 #include <dt-bindings/clock/mpc512x-clock.h>
22
23 #include "mpc512x.h" /* our public mpc5121_clk_init() API */
24
25 /* helpers to keep the MCLK intermediates "somewhere" in our table */
26 enum {
27 MCLK_IDX_MUX0,
28 MCLK_IDX_EN0,
29 MCLK_IDX_DIV0,
30 MCLK_MAX_IDX,
31 };
32
33 #define NR_PSCS 12
34 #define NR_MSCANS 4
35 #define NR_SPDIFS 1
36 #define NR_OUTCLK 4
37 #define NR_MCLKS (NR_PSCS + NR_MSCANS + NR_SPDIFS + NR_OUTCLK)
38
39 /* extend the public set of clocks by adding internal slots for management */
40 enum {
41 /* arrange for adjacent numbers after the public set */
42 MPC512x_CLK_START_PRIVATE = MPC512x_CLK_LAST_PUBLIC,
43 /* clocks which aren't announced to the public */
44 MPC512x_CLK_DDR,
45 MPC512x_CLK_MEM,
46 MPC512x_CLK_IIM,
47 /* intermediates in div+gate combos or fractional dividers */
48 MPC512x_CLK_DDR_UG,
49 MPC512x_CLK_SDHC_x4,
50 MPC512x_CLK_SDHC_UG,
51 MPC512x_CLK_SDHC2_UG,
52 MPC512x_CLK_DIU_x4,
53 MPC512x_CLK_DIU_UG,
54 MPC512x_CLK_MBX_BUS_UG,
55 MPC512x_CLK_MBX_UG,
56 MPC512x_CLK_MBX_3D_UG,
57 MPC512x_CLK_PCI_UG,
58 MPC512x_CLK_NFC_UG,
59 MPC512x_CLK_LPC_UG,
60 MPC512x_CLK_SPDIF_TX_IN,
61 /* intermediates for the mux+gate+div+mux MCLK generation */
62 MPC512x_CLK_MCLKS_FIRST,
63 MPC512x_CLK_MCLKS_LAST = MPC512x_CLK_MCLKS_FIRST
64 + NR_MCLKS * MCLK_MAX_IDX,
65 /* internal, symbolic spec for the number of slots */
66 MPC512x_CLK_LAST_PRIVATE,
67 };
68
69 /* data required for the OF clock provider registration */
70 static struct clk *clks[MPC512x_CLK_LAST_PRIVATE];
71 static struct clk_onecell_data clk_data;
72
73 /* CCM register access */
74 static struct mpc512x_ccm __iomem *clkregs;
75 static DEFINE_SPINLOCK(clklock);
76
77 /* SoC variants {{{ */
78
79 /*
80 * tell SoC variants apart as they are rather similar yet not identical,
81 * cache the result in an enum to not repeatedly run the expensive OF test
82 *
83 * MPC5123 is an MPC5121 without the MBX graphics accelerator
84 *
85 * MPC5125 has many more differences: no MBX, no AXE, no VIU, no SPDIF,
86 * no PATA, no SATA, no PCI, two FECs (of different compatibility name),
87 * only 10 PSCs (of different compatibility name), two SDHCs, different
88 * NFC IP block, output clocks, system PLL status query, different CPMF
89 * interpretation, no CFM, different fourth PSC/CAN mux0 input -- yet
90 * those differences can get folded into this clock provider support
91 * code and don't warrant a separate highly redundant implementation
92 */
93
94 static enum soc_type {
95 MPC512x_SOC_MPC5121,
96 MPC512x_SOC_MPC5123,
97 MPC512x_SOC_MPC5125,
98 } soc;
99
100 static void __init mpc512x_clk_determine_soc(void)
101 {
102 if (of_machine_is_compatible("fsl,mpc5121")) {
103 soc = MPC512x_SOC_MPC5121;
104 return;
105 }
106 if (of_machine_is_compatible("fsl,mpc5123")) {
107 soc = MPC512x_SOC_MPC5123;
108 return;
109 }
110 if (of_machine_is_compatible("fsl,mpc5125")) {
111 soc = MPC512x_SOC_MPC5125;
112 return;
113 }
114 }
115
116 static bool __init soc_has_mbx(void)
117 {
118 if (soc == MPC512x_SOC_MPC5121)
119 return true;
120 return false;
121 }
122
123 static bool __init soc_has_axe(void)
124 {
125 if (soc == MPC512x_SOC_MPC5125)
126 return false;
127 return true;
128 }
129
130 static bool __init soc_has_viu(void)
131 {
132 if (soc == MPC512x_SOC_MPC5125)
133 return false;
134 return true;
135 }
136
137 static bool __init soc_has_spdif(void)
138 {
139 if (soc == MPC512x_SOC_MPC5125)
140 return false;
141 return true;
142 }
143
144 static bool __init soc_has_pata(void)
145 {
146 if (soc == MPC512x_SOC_MPC5125)
147 return false;
148 return true;
149 }
150
151 static bool __init soc_has_sata(void)
152 {
153 if (soc == MPC512x_SOC_MPC5125)
154 return false;
155 return true;
156 }
157
158 static bool __init soc_has_pci(void)
159 {
160 if (soc == MPC512x_SOC_MPC5125)
161 return false;
162 return true;
163 }
164
165 static bool __init soc_has_fec2(void)
166 {
167 if (soc == MPC512x_SOC_MPC5125)
168 return true;
169 return false;
170 }
171
172 static int __init soc_max_pscnum(void)
173 {
174 if (soc == MPC512x_SOC_MPC5125)
175 return 10;
176 return 12;
177 }
178
179 static bool __init soc_has_sdhc2(void)
180 {
181 if (soc == MPC512x_SOC_MPC5125)
182 return true;
183 return false;
184 }
185
186 static bool __init soc_has_nfc_5125(void)
187 {
188 if (soc == MPC512x_SOC_MPC5125)
189 return true;
190 return false;
191 }
192
193 static bool __init soc_has_outclk(void)
194 {
195 if (soc == MPC512x_SOC_MPC5125)
196 return true;
197 return false;
198 }
199
200 static bool __init soc_has_cpmf_0_bypass(void)
201 {
202 if (soc == MPC512x_SOC_MPC5125)
203 return true;
204 return false;
205 }
206
207 static bool __init soc_has_mclk_mux0_canin(void)
208 {
209 if (soc == MPC512x_SOC_MPC5125)
210 return true;
211 return false;
212 }
213
214 /* }}} SoC variants */
215 /* common clk API wrappers {{{ */
216
217 /* convenience wrappers around the common clk API */
218 static inline struct clk *mpc512x_clk_fixed(const char *name, int rate)
219 {
220 return clk_register_fixed_rate(NULL, name, NULL, 0, rate);
221 }
222
223 static inline struct clk *mpc512x_clk_factor(
224 const char *name, const char *parent_name,
225 int mul, int div)
226 {
227 int clkflags;
228
229 clkflags = CLK_SET_RATE_PARENT;
230 return clk_register_fixed_factor(NULL, name, parent_name, clkflags,
231 mul, div);
232 }
233
234 static inline struct clk *mpc512x_clk_divider(
235 const char *name, const char *parent_name, u8 clkflags,
236 u32 __iomem *reg, u8 pos, u8 len, int divflags)
237 {
238 divflags |= CLK_DIVIDER_BIG_ENDIAN;
239 return clk_register_divider(NULL, name, parent_name, clkflags,
240 reg, pos, len, divflags, &clklock);
241 }
242
243 static inline struct clk *mpc512x_clk_divtable(
244 const char *name, const char *parent_name,
245 u32 __iomem *reg, u8 pos, u8 len,
246 const struct clk_div_table *divtab)
247 {
248 u8 divflags;
249
250 divflags = CLK_DIVIDER_BIG_ENDIAN;
251 return clk_register_divider_table(NULL, name, parent_name, 0,
252 reg, pos, len, divflags,
253 divtab, &clklock);
254 }
255
256 static inline struct clk *mpc512x_clk_gated(
257 const char *name, const char *parent_name,
258 u32 __iomem *reg, u8 pos)
259 {
260 int clkflags;
261 u8 gateflags;
262
263 clkflags = CLK_SET_RATE_PARENT;
264 gateflags = CLK_GATE_BIG_ENDIAN;
265 return clk_register_gate(NULL, name, parent_name, clkflags,
266 reg, pos, gateflags, &clklock);
267 }
268
269 static 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 = CLK_MUX_BIG_ENDIAN;
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 */
286 static 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 */
297 static int __init 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 */
315 static int __init 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 */
336 static int __init 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 */
365 static const 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 */
374 static const 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
382 static int __init 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
399 static void __init 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 */
421 static void __init 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 */
500 static const char *parent_names_mux0_spdif[] = {
501 "sys", "ref", "psc-mclk-in", "spdif-tx",
502 };
503
504 static const char *parent_names_mux0_canin[] = {
505 "sys", "ref", "psc-mclk-in", "can-clk-in",
506 };
507
508 enum mclk_type {
509 MCLK_TYPE_PSC,
510 MCLK_TYPE_MSCAN,
511 MCLK_TYPE_SPDIF,
512 MCLK_TYPE_OUTCLK,
513 };
514
515 struct 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
561 static 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
576 static 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
583 static struct mclk_setup_data mclk_spdif_data[] = {
584 MCLK_SETUP_DATA_SPDIF,
585 };
586
587 static 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 */
595 static void __init 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 * individual '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
704 static void __init 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 composites (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 */
940 static void __init 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 */
951 static void __init mpc5121_clk_provide_migration_support(void)
952 {
953 struct device_node *np;
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 np = of_find_compatible_node(NULL, "pci", "fsl,mpc5121-pci");
974 of_node_put(np);
975 if (np)
976 clk_prepare_enable(clks[MPC512x_CLK_PCI]);
977 }
978
979 /*
980 * those macros are not exactly pretty, but they encapsulate a lot
981 * of copy'n'paste heavy code which is even more ugly, and reduce
982 * the potential for inconsistencies in those many code copies
983 */
984 #define FOR_NODES(compatname) \
985 for_each_compatible_node(np, NULL, compatname)
986
987 #define NODE_PREP do { \
988 of_address_to_resource(np, 0, &res); \
989 snprintf(devname, sizeof(devname), "%pa.%s", &res.start, np->name); \
990 } while (0)
991
992 #define NODE_CHK(clkname, clkitem, regnode, regflag) do { \
993 struct clk *clk; \
994 clk = of_clk_get_by_name(np, clkname); \
995 if (IS_ERR(clk)) { \
996 clk = clkitem; \
997 clk_register_clkdev(clk, clkname, devname); \
998 if (regnode) \
999 clk_register_clkdev(clk, clkname, np->name); \
1000 did_register |= DID_REG_ ## regflag; \
1001 pr_debug("clock alias name '%s' for dev '%s' pointer %p\n", \
1002 clkname, devname, clk); \
1003 } else { \
1004 clk_put(clk); \
1005 } \
1006 } while (0)
1007
1008 /*
1009 * register source code provided fallback results for clock lookups,
1010 * these get consulted when OF based clock lookup fails (that is in the
1011 * case of not yet adjusted device tree data, where clock related specs
1012 * are missing)
1013 */
1014 static void __init mpc5121_clk_provide_backwards_compat(void)
1015 {
1016 enum did_reg_flags {
1017 DID_REG_PSC = BIT(0),
1018 DID_REG_PSCFIFO = BIT(1),
1019 DID_REG_NFC = BIT(2),
1020 DID_REG_CAN = BIT(3),
1021 DID_REG_I2C = BIT(4),
1022 DID_REG_DIU = BIT(5),
1023 DID_REG_VIU = BIT(6),
1024 DID_REG_FEC = BIT(7),
1025 DID_REG_USB = BIT(8),
1026 DID_REG_PATA = BIT(9),
1027 };
1028
1029 int did_register;
1030 struct device_node *np;
1031 struct resource res;
1032 int idx;
1033 char devname[32];
1034
1035 did_register = 0;
1036
1037 FOR_NODES(mpc512x_select_psc_compat()) {
1038 NODE_PREP;
1039 idx = (res.start >> 8) & 0xf;
1040 NODE_CHK("ipg", clks[MPC512x_CLK_PSC0 + idx], 0, PSC);
1041 NODE_CHK("mclk", clks[MPC512x_CLK_PSC0_MCLK + idx], 0, PSC);
1042 }
1043
1044 FOR_NODES("fsl,mpc5121-psc-fifo") {
1045 NODE_PREP;
1046 NODE_CHK("ipg", clks[MPC512x_CLK_PSC_FIFO], 1, PSCFIFO);
1047 }
1048
1049 FOR_NODES("fsl,mpc5121-nfc") {
1050 NODE_PREP;
1051 NODE_CHK("ipg", clks[MPC512x_CLK_NFC], 0, NFC);
1052 }
1053
1054 FOR_NODES("fsl,mpc5121-mscan") {
1055 NODE_PREP;
1056 idx = 0;
1057 idx += (res.start & 0x2000) ? 2 : 0;
1058 idx += (res.start & 0x0080) ? 1 : 0;
1059 NODE_CHK("ipg", clks[MPC512x_CLK_BDLC], 0, CAN);
1060 NODE_CHK("mclk", clks[MPC512x_CLK_MSCAN0_MCLK + idx], 0, CAN);
1061 }
1062
1063 /*
1064 * do register the 'ips', 'sys', and 'ref' names globally
1065 * instead of inside each individual CAN node, as there is no
1066 * potential for a name conflict (in contrast to 'ipg' and 'mclk')
1067 */
1068 if (did_register & DID_REG_CAN) {
1069 clk_register_clkdev(clks[MPC512x_CLK_IPS], "ips", NULL);
1070 clk_register_clkdev(clks[MPC512x_CLK_SYS], "sys", NULL);
1071 clk_register_clkdev(clks[MPC512x_CLK_REF], "ref", NULL);
1072 }
1073
1074 FOR_NODES("fsl,mpc5121-i2c") {
1075 NODE_PREP;
1076 NODE_CHK("ipg", clks[MPC512x_CLK_I2C], 0, I2C);
1077 }
1078
1079 /*
1080 * workaround for the fact that the I2C driver does an "anonymous"
1081 * lookup (NULL name spec, which yields the first clock spec) for
1082 * which we cannot register an alias -- a _global_ 'ipg' alias that
1083 * is not bound to any device name and returns the I2C clock item
1084 * is not a good idea
1085 *
1086 * so we have the lookup in the peripheral driver fail, which is
1087 * silent and non-fatal, and pre-enable the clock item here such
1088 * that register access is possible
1089 *
1090 * see commit b3bfce2b "i2c: mpc: cleanup clock API use" for
1091 * details, adjusting s/NULL/"ipg"/ in i2c-mpc.c would make this
1092 * workaround obsolete
1093 */
1094 if (did_register & DID_REG_I2C)
1095 clk_prepare_enable(clks[MPC512x_CLK_I2C]);
1096
1097 FOR_NODES("fsl,mpc5121-diu") {
1098 NODE_PREP;
1099 NODE_CHK("ipg", clks[MPC512x_CLK_DIU], 1, DIU);
1100 }
1101
1102 FOR_NODES("fsl,mpc5121-viu") {
1103 NODE_PREP;
1104 NODE_CHK("ipg", clks[MPC512x_CLK_VIU], 0, VIU);
1105 }
1106
1107 /*
1108 * note that 2771399a "fs_enet: cleanup clock API use" did use the
1109 * "per" string for the clock lookup in contrast to the "ipg" name
1110 * which most other nodes are using -- this is not a fatal thing
1111 * but just something to keep in mind when doing compatibility
1112 * registration, it's a non-issue with up-to-date device tree data
1113 */
1114 FOR_NODES("fsl,mpc5121-fec") {
1115 NODE_PREP;
1116 NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
1117 }
1118 FOR_NODES("fsl,mpc5121-fec-mdio") {
1119 NODE_PREP;
1120 NODE_CHK("per", clks[MPC512x_CLK_FEC], 0, FEC);
1121 }
1122 /*
1123 * MPC5125 has two FECs: FEC1 at 0x2800, FEC2 at 0x4800;
1124 * the clock items don't "form an array" since FEC2 was
1125 * added only later and was not allowed to shift all other
1126 * clock item indices, so the numbers aren't adjacent
1127 */
1128 FOR_NODES("fsl,mpc5125-fec") {
1129 NODE_PREP;
1130 if (res.start & 0x4000)
1131 idx = MPC512x_CLK_FEC2;
1132 else
1133 idx = MPC512x_CLK_FEC;
1134 NODE_CHK("per", clks[idx], 0, FEC);
1135 }
1136
1137 FOR_NODES("fsl,mpc5121-usb2-dr") {
1138 NODE_PREP;
1139 idx = (res.start & 0x4000) ? 1 : 0;
1140 NODE_CHK("ipg", clks[MPC512x_CLK_USB1 + idx], 0, USB);
1141 }
1142
1143 FOR_NODES("fsl,mpc5121-pata") {
1144 NODE_PREP;
1145 NODE_CHK("ipg", clks[MPC512x_CLK_PATA], 0, PATA);
1146 }
1147
1148 /*
1149 * try to collapse diagnostics into a single line of output yet
1150 * provide a full list of what is missing, to avoid noise in the
1151 * absence of up-to-date device tree data -- backwards
1152 * compatibility to old DTBs is a requirement, updates may be
1153 * desirable or preferrable but are not at all mandatory
1154 */
1155 if (did_register) {
1156 pr_notice("device tree lacks clock specs, adding fallbacks (0x%x,%s%s%s%s%s%s%s%s%s%s)\n",
1157 did_register,
1158 (did_register & DID_REG_PSC) ? " PSC" : "",
1159 (did_register & DID_REG_PSCFIFO) ? " PSCFIFO" : "",
1160 (did_register & DID_REG_NFC) ? " NFC" : "",
1161 (did_register & DID_REG_CAN) ? " CAN" : "",
1162 (did_register & DID_REG_I2C) ? " I2C" : "",
1163 (did_register & DID_REG_DIU) ? " DIU" : "",
1164 (did_register & DID_REG_VIU) ? " VIU" : "",
1165 (did_register & DID_REG_FEC) ? " FEC" : "",
1166 (did_register & DID_REG_USB) ? " USB" : "",
1167 (did_register & DID_REG_PATA) ? " PATA" : "");
1168 } else {
1169 pr_debug("device tree has clock specs, no fallbacks added\n");
1170 }
1171 }
1172
1173 /*
1174 * The "fixed-clock" nodes (which includes the oscillator node if the board's
1175 * DT provides one) has already been scanned by the of_clk_init() in
1176 * time_init().
1177 */
1178 int __init mpc5121_clk_init(void)
1179 {
1180 struct device_node *clk_np;
1181 int busfreq;
1182
1183 /* map the clock control registers */
1184 clk_np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
1185 if (!clk_np)
1186 return -ENODEV;
1187 clkregs = of_iomap(clk_np, 0);
1188 WARN_ON(!clkregs);
1189
1190 /* determine the SoC variant we run on */
1191 mpc512x_clk_determine_soc();
1192
1193 /* invalidate all not yet registered clock slots */
1194 mpc512x_clk_preset_data();
1195
1196 /*
1197 * add a dummy clock for those situations where a clock spec is
1198 * required yet no real clock is involved
1199 */
1200 clks[MPC512x_CLK_DUMMY] = mpc512x_clk_fixed("dummy", 0);
1201
1202 /*
1203 * have all the real nodes in the clock tree populated from REF
1204 * down to all leaves, either starting from the OSC node or from
1205 * a REF root that was created from the IPS bus clock input
1206 */
1207 busfreq = get_freq_from_dt("bus-frequency");
1208 mpc512x_clk_setup_clock_tree(clk_np, busfreq);
1209
1210 /* register as an OF clock provider */
1211 mpc5121_clk_register_of_provider(clk_np);
1212
1213 of_node_put(clk_np);
1214
1215 /*
1216 * unbreak not yet adjusted peripheral drivers during migration
1217 * towards fully operational common clock support, and allow
1218 * operation in the absence of clock related device tree specs
1219 */
1220 mpc5121_clk_provide_migration_support();
1221 mpc5121_clk_provide_backwards_compat();
1222
1223 return 0;
1224 }
1225
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