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1/*
2 * Nomadik clock implementation
3 * Copyright (C) 2013 ST-Ericsson AB
4 * License terms: GNU General Public License (GPL) version 2
5 * Author: Linus Walleij <linus.walleij@linaro.org>
6 */
7
8#define pr_fmt(fmt) "Nomadik SRC clocks: " fmt
9
10#include <linux/bitops.h>
11#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/clk-provider.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/debugfs.h>
18#include <linux/seq_file.h>
19#include <linux/spinlock.h>
20#include <linux/reboot.h>
21
22/*
23 * The Nomadik clock tree is described in the STN8815A12 DB V4.2
24 * reference manual for the chip, page 94 ff.
25 * Clock IDs are in the STn8815 Reference Manual table 3, page 27.
26 */
27
28#define SRC_CR 0x00U
29#define SRC_CR_T0_ENSEL BIT(15)
30#define SRC_CR_T1_ENSEL BIT(17)
31#define SRC_CR_T2_ENSEL BIT(19)
32#define SRC_CR_T3_ENSEL BIT(21)
33#define SRC_CR_T4_ENSEL BIT(23)
34#define SRC_CR_T5_ENSEL BIT(25)
35#define SRC_CR_T6_ENSEL BIT(27)
36#define SRC_CR_T7_ENSEL BIT(29)
37#define SRC_XTALCR 0x0CU
38#define SRC_XTALCR_XTALTIMEN BIT(20)
39#define SRC_XTALCR_SXTALDIS BIT(19)
40#define SRC_XTALCR_MXTALSTAT BIT(2)
41#define SRC_XTALCR_MXTALEN BIT(1)
42#define SRC_XTALCR_MXTALOVER BIT(0)
43#define SRC_PLLCR 0x10U
44#define SRC_PLLCR_PLLTIMEN BIT(29)
45#define SRC_PLLCR_PLL2EN BIT(28)
46#define SRC_PLLCR_PLL1STAT BIT(2)
47#define SRC_PLLCR_PLL1EN BIT(1)
48#define SRC_PLLCR_PLL1OVER BIT(0)
49#define SRC_PLLFR 0x14U
50#define SRC_PCKEN0 0x24U
51#define SRC_PCKDIS0 0x28U
52#define SRC_PCKENSR0 0x2CU
53#define SRC_PCKSR0 0x30U
54#define SRC_PCKEN1 0x34U
55#define SRC_PCKDIS1 0x38U
56#define SRC_PCKENSR1 0x3CU
57#define SRC_PCKSR1 0x40U
58
59/* Lock protecting the SRC_CR register */
60static DEFINE_SPINLOCK(src_lock);
61/* Base address of the SRC */
62static void __iomem *src_base;
63
64static int nomadik_clk_reboot_handler(struct notifier_block *this,
65 unsigned long code,
66 void *unused)
67{
68 u32 val;
69
70 /* The main chrystal need to be enabled for reboot to work */
71 val = readl(src_base + SRC_XTALCR);
72 val &= ~SRC_XTALCR_MXTALOVER;
73 val |= SRC_XTALCR_MXTALEN;
74 pr_crit("force-enabling MXTALO\n");
75 writel(val, src_base + SRC_XTALCR);
76 return NOTIFY_OK;
77}
78
79static struct notifier_block nomadik_clk_reboot_notifier = {
80 .notifier_call = nomadik_clk_reboot_handler,
81};
82
83static const struct of_device_id nomadik_src_match[] __initconst = {
84 { .compatible = "stericsson,nomadik-src" },
85 { /* sentinel */ }
86};
87
88static void __init nomadik_src_init(void)
89{
90 struct device_node *np;
91 u32 val;
92
93 np = of_find_matching_node(NULL, nomadik_src_match);
94 if (!np) {
95 pr_crit("no matching node for SRC, aborting clock init\n");
96 return;
97 }
98 src_base = of_iomap(np, 0);
99 if (!src_base) {
100 pr_err("%s: must have src parent node with REGS (%pOFn)\n",
101 __func__, np);
102 return;
103 }
104
105 /* Set all timers to use the 2.4 MHz TIMCLK */
106 val = readl(src_base + SRC_CR);
107 val |= SRC_CR_T0_ENSEL;
108 val |= SRC_CR_T1_ENSEL;
109 val |= SRC_CR_T2_ENSEL;
110 val |= SRC_CR_T3_ENSEL;
111 val |= SRC_CR_T4_ENSEL;
112 val |= SRC_CR_T5_ENSEL;
113 val |= SRC_CR_T6_ENSEL;
114 val |= SRC_CR_T7_ENSEL;
115 writel(val, src_base + SRC_CR);
116
117 val = readl(src_base + SRC_XTALCR);
118 pr_info("SXTALO is %s\n",
119 (val & SRC_XTALCR_SXTALDIS) ? "disabled" : "enabled");
120 pr_info("MXTAL is %s\n",
121 (val & SRC_XTALCR_MXTALSTAT) ? "enabled" : "disabled");
122 if (of_property_read_bool(np, "disable-sxtalo")) {
123 /* The machine uses an external oscillator circuit */
124 val |= SRC_XTALCR_SXTALDIS;
125 pr_info("disabling SXTALO\n");
126 }
127 if (of_property_read_bool(np, "disable-mxtalo")) {
128 /* Disable this too: also run by external oscillator */
129 val |= SRC_XTALCR_MXTALOVER;
130 val &= ~SRC_XTALCR_MXTALEN;
131 pr_info("disabling MXTALO\n");
132 }
133 writel(val, src_base + SRC_XTALCR);
134 register_reboot_notifier(&nomadik_clk_reboot_notifier);
135}
136
137/**
138 * struct clk_pll1 - Nomadik PLL1 clock
139 * @hw: corresponding clock hardware entry
140 * @id: PLL instance: 1 or 2
141 */
142struct clk_pll {
143 struct clk_hw hw;
144 int id;
145};
146
147/**
148 * struct clk_src - Nomadik src clock
149 * @hw: corresponding clock hardware entry
150 * @id: the clock ID
151 * @group1: true if the clock is in group1, else it is in group0
152 * @clkbit: bit 0...31 corresponding to the clock in each clock register
153 */
154struct clk_src {
155 struct clk_hw hw;
156 int id;
157 bool group1;
158 u32 clkbit;
159};
160
161#define to_pll(_hw) container_of(_hw, struct clk_pll, hw)
162#define to_src(_hw) container_of(_hw, struct clk_src, hw)
163
164static int pll_clk_enable(struct clk_hw *hw)
165{
166 struct clk_pll *pll = to_pll(hw);
167 u32 val;
168
169 spin_lock(&src_lock);
170 val = readl(src_base + SRC_PLLCR);
171 if (pll->id == 1) {
172 if (val & SRC_PLLCR_PLL1OVER) {
173 val |= SRC_PLLCR_PLL1EN;
174 writel(val, src_base + SRC_PLLCR);
175 }
176 } else if (pll->id == 2) {
177 val |= SRC_PLLCR_PLL2EN;
178 writel(val, src_base + SRC_PLLCR);
179 }
180 spin_unlock(&src_lock);
181 return 0;
182}
183
184static void pll_clk_disable(struct clk_hw *hw)
185{
186 struct clk_pll *pll = to_pll(hw);
187 u32 val;
188
189 spin_lock(&src_lock);
190 val = readl(src_base + SRC_PLLCR);
191 if (pll->id == 1) {
192 if (val & SRC_PLLCR_PLL1OVER) {
193 val &= ~SRC_PLLCR_PLL1EN;
194 writel(val, src_base + SRC_PLLCR);
195 }
196 } else if (pll->id == 2) {
197 val &= ~SRC_PLLCR_PLL2EN;
198 writel(val, src_base + SRC_PLLCR);
199 }
200 spin_unlock(&src_lock);
201}
202
203static int pll_clk_is_enabled(struct clk_hw *hw)
204{
205 struct clk_pll *pll = to_pll(hw);
206 u32 val;
207
208 val = readl(src_base + SRC_PLLCR);
209 if (pll->id == 1) {
210 if (val & SRC_PLLCR_PLL1OVER)
211 return !!(val & SRC_PLLCR_PLL1EN);
212 } else if (pll->id == 2) {
213 return !!(val & SRC_PLLCR_PLL2EN);
214 }
215 return 1;
216}
217
218static unsigned long pll_clk_recalc_rate(struct clk_hw *hw,
219 unsigned long parent_rate)
220{
221 struct clk_pll *pll = to_pll(hw);
222 u32 val;
223
224 val = readl(src_base + SRC_PLLFR);
225
226 if (pll->id == 1) {
227 u8 mul;
228 u8 div;
229
230 mul = (val >> 8) & 0x3FU;
231 mul += 2;
232 div = val & 0x07U;
233 return (parent_rate * mul) >> div;
234 }
235
236 if (pll->id == 2) {
237 u8 mul;
238
239 mul = (val >> 24) & 0x3FU;
240 mul += 2;
241 return (parent_rate * mul);
242 }
243
244 /* Unknown PLL */
245 return 0;
246}
247
248
249static const struct clk_ops pll_clk_ops = {
250 .enable = pll_clk_enable,
251 .disable = pll_clk_disable,
252 .is_enabled = pll_clk_is_enabled,
253 .recalc_rate = pll_clk_recalc_rate,
254};
255
256static struct clk_hw * __init
257pll_clk_register(struct device *dev, const char *name,
258 const char *parent_name, u32 id)
259{
260 int ret;
261 struct clk_pll *pll;
262 struct clk_init_data init;
263
264 if (id != 1 && id != 2) {
265 pr_err("%s: the Nomadik has only PLL 1 & 2\n", __func__);
266 return ERR_PTR(-EINVAL);
267 }
268
269 pll = kzalloc(sizeof(*pll), GFP_KERNEL);
270 if (!pll)
271 return ERR_PTR(-ENOMEM);
272
273 init.name = name;
274 init.ops = &pll_clk_ops;
275 init.parent_names = (parent_name ? &parent_name : NULL);
276 init.num_parents = (parent_name ? 1 : 0);
277 pll->hw.init = &init;
278 pll->id = id;
279
280 pr_debug("register PLL1 clock \"%s\"\n", name);
281
282 ret = clk_hw_register(dev, &pll->hw);
283 if (ret) {
284 kfree(pll);
285 return ERR_PTR(ret);
286 }
287
288 return &pll->hw;
289}
290
291/*
292 * The Nomadik SRC clocks are gated, but not in the sense that
293 * you read-modify-write a register. Instead there are separate
294 * clock enable and clock disable registers. Writing a '1' bit in
295 * the enable register for a certain clock ungates that clock without
296 * affecting the other clocks. The disable register works the opposite
297 * way.
298 */
299
300static int src_clk_enable(struct clk_hw *hw)
301{
302 struct clk_src *sclk = to_src(hw);
303 u32 enreg = sclk->group1 ? SRC_PCKEN1 : SRC_PCKEN0;
304 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
305
306 writel(sclk->clkbit, src_base + enreg);
307 /* spin until enabled */
308 while (!(readl(src_base + sreg) & sclk->clkbit))
309 cpu_relax();
310 return 0;
311}
312
313static void src_clk_disable(struct clk_hw *hw)
314{
315 struct clk_src *sclk = to_src(hw);
316 u32 disreg = sclk->group1 ? SRC_PCKDIS1 : SRC_PCKDIS0;
317 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
318
319 writel(sclk->clkbit, src_base + disreg);
320 /* spin until disabled */
321 while (readl(src_base + sreg) & sclk->clkbit)
322 cpu_relax();
323}
324
325static int src_clk_is_enabled(struct clk_hw *hw)
326{
327 struct clk_src *sclk = to_src(hw);
328 u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
329 u32 val = readl(src_base + sreg);
330
331 return !!(val & sclk->clkbit);
332}
333
334static unsigned long
335src_clk_recalc_rate(struct clk_hw *hw,
336 unsigned long parent_rate)
337{
338 return parent_rate;
339}
340
341static const struct clk_ops src_clk_ops = {
342 .enable = src_clk_enable,
343 .disable = src_clk_disable,
344 .is_enabled = src_clk_is_enabled,
345 .recalc_rate = src_clk_recalc_rate,
346};
347
348static struct clk_hw * __init
349src_clk_register(struct device *dev, const char *name,
350 const char *parent_name, u8 id)
351{
352 int ret;
353 struct clk_src *sclk;
354 struct clk_init_data init;
355
356 sclk = kzalloc(sizeof(*sclk), GFP_KERNEL);
357 if (!sclk)
358 return ERR_PTR(-ENOMEM);
359
360 init.name = name;
361 init.ops = &src_clk_ops;
362 /* Do not force-disable the static SDRAM controller */
363 if (id == 2)
364 init.flags = CLK_IGNORE_UNUSED;
365 else
366 init.flags = 0;
367 init.parent_names = (parent_name ? &parent_name : NULL);
368 init.num_parents = (parent_name ? 1 : 0);
369 sclk->hw.init = &init;
370 sclk->id = id;
371 sclk->group1 = (id > 31);
372 sclk->clkbit = BIT(id & 0x1f);
373
374 pr_debug("register clock \"%s\" ID: %d group: %d bits: %08x\n",
375 name, id, sclk->group1, sclk->clkbit);
376
377 ret = clk_hw_register(dev, &sclk->hw);
378 if (ret) {
379 kfree(sclk);
380 return ERR_PTR(ret);
381 }
382
383 return &sclk->hw;
384}
385
386#ifdef CONFIG_DEBUG_FS
387
388static u32 src_pcksr0_boot;
389static u32 src_pcksr1_boot;
390
391static const char * const src_clk_names[] = {
392 "HCLKDMA0 ",
393 "HCLKSMC ",
394 "HCLKSDRAM ",
395 "HCLKDMA1 ",
396 "HCLKCLCD ",
397 "PCLKIRDA ",
398 "PCLKSSP ",
399 "PCLKUART0 ",
400 "PCLKSDI ",
401 "PCLKI2C0 ",
402 "PCLKI2C1 ",
403 "PCLKUART1 ",
404 "PCLMSP0 ",
405 "HCLKUSB ",
406 "HCLKDIF ",
407 "HCLKSAA ",
408 "HCLKSVA ",
409 "PCLKHSI ",
410 "PCLKXTI ",
411 "PCLKUART2 ",
412 "PCLKMSP1 ",
413 "PCLKMSP2 ",
414 "PCLKOWM ",
415 "HCLKHPI ",
416 "PCLKSKE ",
417 "PCLKHSEM ",
418 "HCLK3D ",
419 "HCLKHASH ",
420 "HCLKCRYP ",
421 "PCLKMSHC ",
422 "HCLKUSBM ",
423 "HCLKRNG ",
424 "RESERVED ",
425 "RESERVED ",
426 "RESERVED ",
427 "RESERVED ",
428 "CLDCLK ",
429 "IRDACLK ",
430 "SSPICLK ",
431 "UART0CLK ",
432 "SDICLK ",
433 "I2C0CLK ",
434 "I2C1CLK ",
435 "UART1CLK ",
436 "MSPCLK0 ",
437 "USBCLK ",
438 "DIFCLK ",
439 "IPI2CCLK ",
440 "IPBMCCLK ",
441 "HSICLKRX ",
442 "HSICLKTX ",
443 "UART2CLK ",
444 "MSPCLK1 ",
445 "MSPCLK2 ",
446 "OWMCLK ",
447 "RESERVED ",
448 "SKECLK ",
449 "RESERVED ",
450 "3DCLK ",
451 "PCLKMSP3 ",
452 "MSPCLK3 ",
453 "MSHCCLK ",
454 "USBMCLK ",
455 "RNGCCLK ",
456};
457
458static int nomadik_src_clk_debugfs_show(struct seq_file *s, void *what)
459{
460 int i;
461 u32 src_pcksr0 = readl(src_base + SRC_PCKSR0);
462 u32 src_pcksr1 = readl(src_base + SRC_PCKSR1);
463 u32 src_pckensr0 = readl(src_base + SRC_PCKENSR0);
464 u32 src_pckensr1 = readl(src_base + SRC_PCKENSR1);
465
466 seq_puts(s, "Clock: Boot: Now: Request: ASKED:\n");
467 for (i = 0; i < ARRAY_SIZE(src_clk_names); i++) {
468 u32 pcksrb = (i < 0x20) ? src_pcksr0_boot : src_pcksr1_boot;
469 u32 pcksr = (i < 0x20) ? src_pcksr0 : src_pcksr1;
470 u32 pckreq = (i < 0x20) ? src_pckensr0 : src_pckensr1;
471 u32 mask = BIT(i & 0x1f);
472
473 seq_printf(s, "%s %s %s %s\n",
474 src_clk_names[i],
475 (pcksrb & mask) ? "on " : "off",
476 (pcksr & mask) ? "on " : "off",
477 (pckreq & mask) ? "on " : "off");
478 }
479 return 0;
480}
481
482DEFINE_SHOW_ATTRIBUTE(nomadik_src_clk_debugfs);
483
484static int __init nomadik_src_clk_init_debugfs(void)
485{
486 /* Vital for multiplatform */
487 if (!src_base)
488 return -ENODEV;
489 src_pcksr0_boot = readl(src_base + SRC_PCKSR0);
490 src_pcksr1_boot = readl(src_base + SRC_PCKSR1);
491 debugfs_create_file("nomadik-src-clk", S_IFREG | S_IRUGO,
492 NULL, NULL, &nomadik_src_clk_debugfs_fops);
493 return 0;
494}
495device_initcall(nomadik_src_clk_init_debugfs);
496
497#endif
498
499static void __init of_nomadik_pll_setup(struct device_node *np)
500{
501 struct clk_hw *hw;
502 const char *clk_name = np->name;
503 const char *parent_name;
504 u32 pll_id;
505
506 if (!src_base)
507 nomadik_src_init();
508
509 if (of_property_read_u32(np, "pll-id", &pll_id)) {
510 pr_err("%s: PLL \"%s\" missing pll-id property\n",
511 __func__, clk_name);
512 return;
513 }
514 parent_name = of_clk_get_parent_name(np, 0);
515 hw = pll_clk_register(NULL, clk_name, parent_name, pll_id);
516 if (!IS_ERR(hw))
517 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
518}
519CLK_OF_DECLARE(nomadik_pll_clk,
520 "st,nomadik-pll-clock", of_nomadik_pll_setup);
521
522static void __init of_nomadik_hclk_setup(struct device_node *np)
523{
524 struct clk_hw *hw;
525 const char *clk_name = np->name;
526 const char *parent_name;
527
528 if (!src_base)
529 nomadik_src_init();
530
531 parent_name = of_clk_get_parent_name(np, 0);
532 /*
533 * The HCLK divides PLL1 with 1 (passthru), 2, 3 or 4.
534 */
535 hw = clk_hw_register_divider(NULL, clk_name, parent_name,
536 0, src_base + SRC_CR,
537 13, 2,
538 CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO,
539 &src_lock);
540 if (!IS_ERR(hw))
541 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
542}
543CLK_OF_DECLARE(nomadik_hclk_clk,
544 "st,nomadik-hclk-clock", of_nomadik_hclk_setup);
545
546static void __init of_nomadik_src_clk_setup(struct device_node *np)
547{
548 struct clk_hw *hw;
549 const char *clk_name = np->name;
550 const char *parent_name;
551 u32 clk_id;
552
553 if (!src_base)
554 nomadik_src_init();
555
556 if (of_property_read_u32(np, "clock-id", &clk_id)) {
557 pr_err("%s: SRC clock \"%s\" missing clock-id property\n",
558 __func__, clk_name);
559 return;
560 }
561 parent_name = of_clk_get_parent_name(np, 0);
562 hw = src_clk_register(NULL, clk_name, parent_name, clk_id);
563 if (!IS_ERR(hw))
564 of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
565}
566CLK_OF_DECLARE(nomadik_src_clk,
567 "st,nomadik-src-clock", of_nomadik_src_clk_setup);
568

Warning: That file was not part of the compilation database. It may have many parsing errors.