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1/*
2 * arch/arm/mach-ep93xx/clock.c
3 * Clock control for Cirrus EP93xx chips.
4 *
5 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or (at
10 * your option) any later version.
11 */
12
13#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
14
15#include <linux/kernel.h>
16#include <linux/clk.h>
17#include <linux/err.h>
18#include <linux/module.h>
19#include <linux/string.h>
20#include <linux/io.h>
21#include <linux/spinlock.h>
22#include <linux/clkdev.h>
23
24#include <mach/hardware.h>
25
26#include <asm/div64.h>
27
28
29struct clk {
30 struct clk *parent;
31 unsigned long rate;
32 int users;
33 int sw_locked;
34 void __iomem *enable_reg;
35 u32 enable_mask;
36
37 unsigned long (*get_rate)(struct clk *clk);
38 int (*set_rate)(struct clk *clk, unsigned long rate);
39};
40
41
42static unsigned long get_uart_rate(struct clk *clk);
43
44static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
45static int set_div_rate(struct clk *clk, unsigned long rate);
46static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate);
47static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate);
48
49static struct clk clk_xtali = {
50 .rate = EP93XX_EXT_CLK_RATE,
51};
52static struct clk clk_uart1 = {
53 .parent = &clk_xtali,
54 .sw_locked = 1,
55 .enable_reg = EP93XX_SYSCON_DEVCFG,
56 .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN,
57 .get_rate = get_uart_rate,
58};
59static struct clk clk_uart2 = {
60 .parent = &clk_xtali,
61 .sw_locked = 1,
62 .enable_reg = EP93XX_SYSCON_DEVCFG,
63 .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN,
64 .get_rate = get_uart_rate,
65};
66static struct clk clk_uart3 = {
67 .parent = &clk_xtali,
68 .sw_locked = 1,
69 .enable_reg = EP93XX_SYSCON_DEVCFG,
70 .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN,
71 .get_rate = get_uart_rate,
72};
73static struct clk clk_pll1 = {
74 .parent = &clk_xtali,
75};
76static struct clk clk_f = {
77 .parent = &clk_pll1,
78};
79static struct clk clk_h = {
80 .parent = &clk_pll1,
81};
82static struct clk clk_p = {
83 .parent = &clk_pll1,
84};
85static struct clk clk_pll2 = {
86 .parent = &clk_xtali,
87};
88static struct clk clk_usb_host = {
89 .parent = &clk_pll2,
90 .enable_reg = EP93XX_SYSCON_PWRCNT,
91 .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN,
92};
93static struct clk clk_keypad = {
94 .parent = &clk_xtali,
95 .sw_locked = 1,
96 .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV,
97 .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
98 .set_rate = set_keytchclk_rate,
99};
100static struct clk clk_spi = {
101 .parent = &clk_xtali,
102 .rate = EP93XX_EXT_CLK_RATE,
103};
104static struct clk clk_pwm = {
105 .parent = &clk_xtali,
106 .rate = EP93XX_EXT_CLK_RATE,
107};
108
109static struct clk clk_video = {
110 .sw_locked = 1,
111 .enable_reg = EP93XX_SYSCON_VIDCLKDIV,
112 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
113 .set_rate = set_div_rate,
114};
115
116static struct clk clk_i2s_mclk = {
117 .sw_locked = 1,
118 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
119 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
120 .set_rate = set_div_rate,
121};
122
123static struct clk clk_i2s_sclk = {
124 .sw_locked = 1,
125 .parent = &clk_i2s_mclk,
126 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
127 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
128 .set_rate = set_i2s_sclk_rate,
129};
130
131static struct clk clk_i2s_lrclk = {
132 .sw_locked = 1,
133 .parent = &clk_i2s_sclk,
134 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
135 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
136 .set_rate = set_i2s_lrclk_rate,
137};
138
139/* DMA Clocks */
140static struct clk clk_m2p0 = {
141 .parent = &clk_h,
142 .enable_reg = EP93XX_SYSCON_PWRCNT,
143 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0,
144};
145static struct clk clk_m2p1 = {
146 .parent = &clk_h,
147 .enable_reg = EP93XX_SYSCON_PWRCNT,
148 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1,
149};
150static struct clk clk_m2p2 = {
151 .parent = &clk_h,
152 .enable_reg = EP93XX_SYSCON_PWRCNT,
153 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2,
154};
155static struct clk clk_m2p3 = {
156 .parent = &clk_h,
157 .enable_reg = EP93XX_SYSCON_PWRCNT,
158 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3,
159};
160static struct clk clk_m2p4 = {
161 .parent = &clk_h,
162 .enable_reg = EP93XX_SYSCON_PWRCNT,
163 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4,
164};
165static struct clk clk_m2p5 = {
166 .parent = &clk_h,
167 .enable_reg = EP93XX_SYSCON_PWRCNT,
168 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5,
169};
170static struct clk clk_m2p6 = {
171 .parent = &clk_h,
172 .enable_reg = EP93XX_SYSCON_PWRCNT,
173 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6,
174};
175static struct clk clk_m2p7 = {
176 .parent = &clk_h,
177 .enable_reg = EP93XX_SYSCON_PWRCNT,
178 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7,
179};
180static struct clk clk_m2p8 = {
181 .parent = &clk_h,
182 .enable_reg = EP93XX_SYSCON_PWRCNT,
183 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8,
184};
185static struct clk clk_m2p9 = {
186 .parent = &clk_h,
187 .enable_reg = EP93XX_SYSCON_PWRCNT,
188 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9,
189};
190static struct clk clk_m2m0 = {
191 .parent = &clk_h,
192 .enable_reg = EP93XX_SYSCON_PWRCNT,
193 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0,
194};
195static struct clk clk_m2m1 = {
196 .parent = &clk_h,
197 .enable_reg = EP93XX_SYSCON_PWRCNT,
198 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1,
199};
200
201#define INIT_CK(dev,con,ck) \
202 { .dev_id = dev, .con_id = con, .clk = ck }
203
204static struct clk_lookup clocks[] = {
205 INIT_CK(NULL, "xtali", &clk_xtali),
206 INIT_CK("apb:uart1", NULL, &clk_uart1),
207 INIT_CK("apb:uart2", NULL, &clk_uart2),
208 INIT_CK("apb:uart3", NULL, &clk_uart3),
209 INIT_CK(NULL, "pll1", &clk_pll1),
210 INIT_CK(NULL, "fclk", &clk_f),
211 INIT_CK(NULL, "hclk", &clk_h),
212 INIT_CK(NULL, "apb_pclk", &clk_p),
213 INIT_CK(NULL, "pll2", &clk_pll2),
214 INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
215 INIT_CK("ep93xx-keypad", NULL, &clk_keypad),
216 INIT_CK("ep93xx-fb", NULL, &clk_video),
217 INIT_CK("ep93xx-spi.0", NULL, &clk_spi),
218 INIT_CK("ep93xx-i2s", "mclk", &clk_i2s_mclk),
219 INIT_CK("ep93xx-i2s", "sclk", &clk_i2s_sclk),
220 INIT_CK("ep93xx-i2s", "lrclk", &clk_i2s_lrclk),
221 INIT_CK(NULL, "pwm_clk", &clk_pwm),
222 INIT_CK(NULL, "m2p0", &clk_m2p0),
223 INIT_CK(NULL, "m2p1", &clk_m2p1),
224 INIT_CK(NULL, "m2p2", &clk_m2p2),
225 INIT_CK(NULL, "m2p3", &clk_m2p3),
226 INIT_CK(NULL, "m2p4", &clk_m2p4),
227 INIT_CK(NULL, "m2p5", &clk_m2p5),
228 INIT_CK(NULL, "m2p6", &clk_m2p6),
229 INIT_CK(NULL, "m2p7", &clk_m2p7),
230 INIT_CK(NULL, "m2p8", &clk_m2p8),
231 INIT_CK(NULL, "m2p9", &clk_m2p9),
232 INIT_CK(NULL, "m2m0", &clk_m2m0),
233 INIT_CK(NULL, "m2m1", &clk_m2m1),
234};
235
236static DEFINE_SPINLOCK(clk_lock);
237
238static void __clk_enable(struct clk *clk)
239{
240 if (!clk->users++) {
241 if (clk->parent)
242 __clk_enable(clk->parent);
243
244 if (clk->enable_reg) {
245 u32 v;
246
247 v = __raw_readl(clk->enable_reg);
248 v |= clk->enable_mask;
249 if (clk->sw_locked)
250 ep93xx_syscon_swlocked_write(v, clk->enable_reg);
251 else
252 __raw_writel(v, clk->enable_reg);
253 }
254 }
255}
256
257int clk_enable(struct clk *clk)
258{
259 unsigned long flags;
260
261 if (!clk)
262 return -EINVAL;
263
264 spin_lock_irqsave(&clk_lock, flags);
265 __clk_enable(clk);
266 spin_unlock_irqrestore(&clk_lock, flags);
267
268 return 0;
269}
270EXPORT_SYMBOL(clk_enable);
271
272static void __clk_disable(struct clk *clk)
273{
274 if (!--clk->users) {
275 if (clk->enable_reg) {
276 u32 v;
277
278 v = __raw_readl(clk->enable_reg);
279 v &= ~clk->enable_mask;
280 if (clk->sw_locked)
281 ep93xx_syscon_swlocked_write(v, clk->enable_reg);
282 else
283 __raw_writel(v, clk->enable_reg);
284 }
285
286 if (clk->parent)
287 __clk_disable(clk->parent);
288 }
289}
290
291void clk_disable(struct clk *clk)
292{
293 unsigned long flags;
294
295 if (!clk)
296 return;
297
298 spin_lock_irqsave(&clk_lock, flags);
299 __clk_disable(clk);
300 spin_unlock_irqrestore(&clk_lock, flags);
301}
302EXPORT_SYMBOL(clk_disable);
303
304static unsigned long get_uart_rate(struct clk *clk)
305{
306 unsigned long rate = clk_get_rate(clk->parent);
307 u32 value;
308
309 value = __raw_readl(EP93XX_SYSCON_PWRCNT);
310 if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD)
311 return rate;
312 else
313 return rate / 2;
314}
315
316unsigned long clk_get_rate(struct clk *clk)
317{
318 if (clk->get_rate)
319 return clk->get_rate(clk);
320
321 return clk->rate;
322}
323EXPORT_SYMBOL(clk_get_rate);
324
325static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
326{
327 u32 val;
328 u32 div_bit;
329
330 val = __raw_readl(clk->enable_reg);
331
332 /*
333 * The Key Matrix and ADC clocks are configured using the same
334 * System Controller register. The clock used will be either
335 * 1/4 or 1/16 the external clock rate depending on the
336 * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV
337 * bit being set or cleared.
338 */
339 div_bit = clk->enable_mask >> 15;
340
341 if (rate == EP93XX_KEYTCHCLK_DIV4)
342 val |= div_bit;
343 else if (rate == EP93XX_KEYTCHCLK_DIV16)
344 val &= ~div_bit;
345 else
346 return -EINVAL;
347
348 ep93xx_syscon_swlocked_write(val, clk->enable_reg);
349 clk->rate = rate;
350 return 0;
351}
352
353static int calc_clk_div(struct clk *clk, unsigned long rate,
354 int *psel, int *esel, int *pdiv, int *div)
355{
356 struct clk *mclk;
357 unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1;
358 int i, found = 0, __div = 0, __pdiv = 0;
359
360 /* Don't exceed the maximum rate */
361 max_rate = max3(clk_pll1.rate / 4, clk_pll2.rate / 4, clk_xtali.rate / 4);
362 rate = min(rate, max_rate);
363
364 /*
365 * Try the two pll's and the external clock
366 * Because the valid predividers are 2, 2.5 and 3, we multiply
367 * all the clocks by 2 to avoid floating point math.
368 *
369 * This is based on the algorithm in the ep93xx raster guide:
370 * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
371 *
372 */
373 for (i = 0; i < 3; i++) {
374 if (i == 0)
375 mclk = &clk_xtali;
376 else if (i == 1)
377 mclk = &clk_pll1;
378 else
379 mclk = &clk_pll2;
380 mclk_rate = mclk->rate * 2;
381
382 /* Try each predivider value */
383 for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
384 __div = mclk_rate / (rate * __pdiv);
385 if (__div < 2 || __div > 127)
386 continue;
387
388 actual_rate = mclk_rate / (__pdiv * __div);
389
390 if (!found || abs(actual_rate - rate) < rate_err) {
391 *pdiv = __pdiv - 3;
392 *div = __div;
393 *psel = (i == 2);
394 *esel = (i != 0);
395 clk->parent = mclk;
396 clk->rate = actual_rate;
397 rate_err = abs(actual_rate - rate);
398 found = 1;
399 }
400 }
401 }
402
403 if (!found)
404 return -EINVAL;
405
406 return 0;
407}
408
409static int set_div_rate(struct clk *clk, unsigned long rate)
410{
411 int err, psel = 0, esel = 0, pdiv = 0, div = 0;
412 u32 val;
413
414 err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div);
415 if (err)
416 return err;
417
418 /* Clear the esel, psel, pdiv and div bits */
419 val = __raw_readl(clk->enable_reg);
420 val &= ~0x7fff;
421
422 /* Set the new esel, psel, pdiv and div bits for the new clock rate */
423 val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
424 (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
425 (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
426 ep93xx_syscon_swlocked_write(val, clk->enable_reg);
427 return 0;
428}
429
430static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate)
431{
432 unsigned val = __raw_readl(clk->enable_reg);
433
434 if (rate == clk_i2s_mclk.rate / 2)
435 ep93xx_syscon_swlocked_write(val & ~EP93XX_I2SCLKDIV_SDIV,
436 clk->enable_reg);
437 else if (rate == clk_i2s_mclk.rate / 4)
438 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_SDIV,
439 clk->enable_reg);
440 else
441 return -EINVAL;
442
443 clk_i2s_sclk.rate = rate;
444 return 0;
445}
446
447static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate)
448{
449 unsigned val = __raw_readl(clk->enable_reg) &
450 ~EP93XX_I2SCLKDIV_LRDIV_MASK;
451
452 if (rate == clk_i2s_sclk.rate / 32)
453 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV32,
454 clk->enable_reg);
455 else if (rate == clk_i2s_sclk.rate / 64)
456 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV64,
457 clk->enable_reg);
458 else if (rate == clk_i2s_sclk.rate / 128)
459 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV128,
460 clk->enable_reg);
461 else
462 return -EINVAL;
463
464 clk_i2s_lrclk.rate = rate;
465 return 0;
466}
467
468int clk_set_rate(struct clk *clk, unsigned long rate)
469{
470 if (clk->set_rate)
471 return clk->set_rate(clk, rate);
472
473 return -EINVAL;
474}
475EXPORT_SYMBOL(clk_set_rate);
476
477
478static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
479static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
480static char pclk_divisors[] = { 1, 2, 4, 8 };
481
482/*
483 * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
484 */
485static unsigned long calc_pll_rate(u32 config_word)
486{
487 unsigned long long rate;
488 int i;
489
490 rate = clk_xtali.rate;
491 rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
492 rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
493 do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
494 for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
495 rate >>= 1;
496
497 return (unsigned long)rate;
498}
499
500static void __init ep93xx_dma_clock_init(void)
501{
502 clk_m2p0.rate = clk_h.rate;
503 clk_m2p1.rate = clk_h.rate;
504 clk_m2p2.rate = clk_h.rate;
505 clk_m2p3.rate = clk_h.rate;
506 clk_m2p4.rate = clk_h.rate;
507 clk_m2p5.rate = clk_h.rate;
508 clk_m2p6.rate = clk_h.rate;
509 clk_m2p7.rate = clk_h.rate;
510 clk_m2p8.rate = clk_h.rate;
511 clk_m2p9.rate = clk_h.rate;
512 clk_m2m0.rate = clk_h.rate;
513 clk_m2m1.rate = clk_h.rate;
514}
515
516static int __init ep93xx_clock_init(void)
517{
518 u32 value;
519
520 /* Determine the bootloader configured pll1 rate */
521 value = __raw_readl(EP93XX_SYSCON_CLKSET1);
522 if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1))
523 clk_pll1.rate = clk_xtali.rate;
524 else
525 clk_pll1.rate = calc_pll_rate(value);
526
527 /* Initialize the pll1 derived clocks */
528 clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
529 clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
530 clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
531 ep93xx_dma_clock_init();
532
533 /* Determine the bootloader configured pll2 rate */
534 value = __raw_readl(EP93XX_SYSCON_CLKSET2);
535 if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2))
536 clk_pll2.rate = clk_xtali.rate;
537 else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN)
538 clk_pll2.rate = calc_pll_rate(value);
539 else
540 clk_pll2.rate = 0;
541
542 /* Initialize the pll2 derived clocks */
543 clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
544
545 /*
546 * EP93xx SSP clock rate was doubled in version E2. For more information
547 * see:
548 * http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
549 */
550 if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2)
551 clk_spi.rate /= 2;
552
553 pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
554 clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
555 pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
556 clk_f.rate / 1000000, clk_h.rate / 1000000,
557 clk_p.rate / 1000000);
558
559 clkdev_add_table(clocks, ARRAY_SIZE(clocks));
560 return 0;
561}
562postcore_initcall(ep93xx_clock_init);