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 #include "soc.h"
29
30 struct clk {
31 struct clk *parent;
32 unsigned long rate;
33 int users;
34 int sw_locked;
35 void __iomem *enable_reg;
36 u32 enable_mask;
37
38 unsigned long (*get_rate)(struct clk *clk);
39 int (*set_rate)(struct clk *clk, unsigned long rate);
40 };
41
42
43 static unsigned long get_uart_rate(struct clk *clk);
44
45 static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
46 static int set_div_rate(struct clk *clk, unsigned long rate);
47 static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate);
48 static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate);
49
50 static struct clk clk_xtali = {
51 .rate = EP93XX_EXT_CLK_RATE,
52 };
53 static struct clk clk_uart1 = {
54 .parent = &clk_xtali,
55 .sw_locked = 1,
56 .enable_reg = EP93XX_SYSCON_DEVCFG,
57 .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN,
58 .get_rate = get_uart_rate,
59 };
60 static struct clk clk_uart2 = {
61 .parent = &clk_xtali,
62 .sw_locked = 1,
63 .enable_reg = EP93XX_SYSCON_DEVCFG,
64 .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN,
65 .get_rate = get_uart_rate,
66 };
67 static struct clk clk_uart3 = {
68 .parent = &clk_xtali,
69 .sw_locked = 1,
70 .enable_reg = EP93XX_SYSCON_DEVCFG,
71 .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN,
72 .get_rate = get_uart_rate,
73 };
74 static struct clk clk_pll1 = {
75 .parent = &clk_xtali,
76 };
77 static struct clk clk_f = {
78 .parent = &clk_pll1,
79 };
80 static struct clk clk_h = {
81 .parent = &clk_pll1,
82 };
83 static struct clk clk_p = {
84 .parent = &clk_pll1,
85 };
86 static struct clk clk_pll2 = {
87 .parent = &clk_xtali,
88 };
89 static struct clk clk_usb_host = {
90 .parent = &clk_pll2,
91 .enable_reg = EP93XX_SYSCON_PWRCNT,
92 .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN,
93 };
94 static struct clk clk_keypad = {
95 .parent = &clk_xtali,
96 .sw_locked = 1,
97 .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV,
98 .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
99 .set_rate = set_keytchclk_rate,
100 };
101 static struct clk clk_spi = {
102 .parent = &clk_xtali,
103 .rate = EP93XX_EXT_CLK_RATE,
104 };
105 static struct clk clk_pwm = {
106 .parent = &clk_xtali,
107 .rate = EP93XX_EXT_CLK_RATE,
108 };
109
110 static struct clk clk_video = {
111 .sw_locked = 1,
112 .enable_reg = EP93XX_SYSCON_VIDCLKDIV,
113 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
114 .set_rate = set_div_rate,
115 };
116
117 static struct clk clk_i2s_mclk = {
118 .sw_locked = 1,
119 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
120 .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
121 .set_rate = set_div_rate,
122 };
123
124 static struct clk clk_i2s_sclk = {
125 .sw_locked = 1,
126 .parent = &clk_i2s_mclk,
127 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
128 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
129 .set_rate = set_i2s_sclk_rate,
130 };
131
132 static struct clk clk_i2s_lrclk = {
133 .sw_locked = 1,
134 .parent = &clk_i2s_sclk,
135 .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
136 .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
137 .set_rate = set_i2s_lrclk_rate,
138 };
139
140 /* DMA Clocks */
141 static struct clk clk_m2p0 = {
142 .parent = &clk_h,
143 .enable_reg = EP93XX_SYSCON_PWRCNT,
144 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0,
145 };
146 static struct clk clk_m2p1 = {
147 .parent = &clk_h,
148 .enable_reg = EP93XX_SYSCON_PWRCNT,
149 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1,
150 };
151 static struct clk clk_m2p2 = {
152 .parent = &clk_h,
153 .enable_reg = EP93XX_SYSCON_PWRCNT,
154 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2,
155 };
156 static struct clk clk_m2p3 = {
157 .parent = &clk_h,
158 .enable_reg = EP93XX_SYSCON_PWRCNT,
159 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3,
160 };
161 static struct clk clk_m2p4 = {
162 .parent = &clk_h,
163 .enable_reg = EP93XX_SYSCON_PWRCNT,
164 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4,
165 };
166 static struct clk clk_m2p5 = {
167 .parent = &clk_h,
168 .enable_reg = EP93XX_SYSCON_PWRCNT,
169 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5,
170 };
171 static struct clk clk_m2p6 = {
172 .parent = &clk_h,
173 .enable_reg = EP93XX_SYSCON_PWRCNT,
174 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6,
175 };
176 static struct clk clk_m2p7 = {
177 .parent = &clk_h,
178 .enable_reg = EP93XX_SYSCON_PWRCNT,
179 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7,
180 };
181 static struct clk clk_m2p8 = {
182 .parent = &clk_h,
183 .enable_reg = EP93XX_SYSCON_PWRCNT,
184 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8,
185 };
186 static struct clk clk_m2p9 = {
187 .parent = &clk_h,
188 .enable_reg = EP93XX_SYSCON_PWRCNT,
189 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9,
190 };
191 static struct clk clk_m2m0 = {
192 .parent = &clk_h,
193 .enable_reg = EP93XX_SYSCON_PWRCNT,
194 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0,
195 };
196 static struct clk clk_m2m1 = {
197 .parent = &clk_h,
198 .enable_reg = EP93XX_SYSCON_PWRCNT,
199 .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1,
200 };
201
202 #define INIT_CK(dev,con,ck) \
203 { .dev_id = dev, .con_id = con, .clk = ck }
204
205 static struct clk_lookup clocks[] = {
206 INIT_CK(NULL, "xtali", &clk_xtali),
207 INIT_CK("apb:uart1", NULL, &clk_uart1),
208 INIT_CK("apb:uart2", NULL, &clk_uart2),
209 INIT_CK("apb:uart3", NULL, &clk_uart3),
210 INIT_CK(NULL, "pll1", &clk_pll1),
211 INIT_CK(NULL, "fclk", &clk_f),
212 INIT_CK(NULL, "hclk", &clk_h),
213 INIT_CK(NULL, "apb_pclk", &clk_p),
214 INIT_CK(NULL, "pll2", &clk_pll2),
215 INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
216 INIT_CK("ep93xx-keypad", NULL, &clk_keypad),
217 INIT_CK("ep93xx-fb", NULL, &clk_video),
218 INIT_CK("ep93xx-spi.0", NULL, &clk_spi),
219 INIT_CK("ep93xx-i2s", "mclk", &clk_i2s_mclk),
220 INIT_CK("ep93xx-i2s", "sclk", &clk_i2s_sclk),
221 INIT_CK("ep93xx-i2s", "lrclk", &clk_i2s_lrclk),
222 INIT_CK(NULL, "pwm_clk", &clk_pwm),
223 INIT_CK(NULL, "m2p0", &clk_m2p0),
224 INIT_CK(NULL, "m2p1", &clk_m2p1),
225 INIT_CK(NULL, "m2p2", &clk_m2p2),
226 INIT_CK(NULL, "m2p3", &clk_m2p3),
227 INIT_CK(NULL, "m2p4", &clk_m2p4),
228 INIT_CK(NULL, "m2p5", &clk_m2p5),
229 INIT_CK(NULL, "m2p6", &clk_m2p6),
230 INIT_CK(NULL, "m2p7", &clk_m2p7),
231 INIT_CK(NULL, "m2p8", &clk_m2p8),
232 INIT_CK(NULL, "m2p9", &clk_m2p9),
233 INIT_CK(NULL, "m2m0", &clk_m2m0),
234 INIT_CK(NULL, "m2m1", &clk_m2m1),
235 };
236
237 static DEFINE_SPINLOCK(clk_lock);
238
__clk_enable(struct clk * clk)239 static void __clk_enable(struct clk *clk)
240 {
241 if (!clk->users++) {
242 if (clk->parent)
243 __clk_enable(clk->parent);
244
245 if (clk->enable_reg) {
246 u32 v;
247
248 v = __raw_readl(clk->enable_reg);
249 v |= clk->enable_mask;
250 if (clk->sw_locked)
251 ep93xx_syscon_swlocked_write(v, clk->enable_reg);
252 else
253 __raw_writel(v, clk->enable_reg);
254 }
255 }
256 }
257
clk_enable(struct clk * clk)258 int clk_enable(struct clk *clk)
259 {
260 unsigned long flags;
261
262 if (!clk)
263 return -EINVAL;
264
265 spin_lock_irqsave(&clk_lock, flags);
266 __clk_enable(clk);
267 spin_unlock_irqrestore(&clk_lock, flags);
268
269 return 0;
270 }
271 EXPORT_SYMBOL(clk_enable);
272
__clk_disable(struct clk * clk)273 static void __clk_disable(struct clk *clk)
274 {
275 if (!--clk->users) {
276 if (clk->enable_reg) {
277 u32 v;
278
279 v = __raw_readl(clk->enable_reg);
280 v &= ~clk->enable_mask;
281 if (clk->sw_locked)
282 ep93xx_syscon_swlocked_write(v, clk->enable_reg);
283 else
284 __raw_writel(v, clk->enable_reg);
285 }
286
287 if (clk->parent)
288 __clk_disable(clk->parent);
289 }
290 }
291
clk_disable(struct clk * clk)292 void clk_disable(struct clk *clk)
293 {
294 unsigned long flags;
295
296 if (!clk)
297 return;
298
299 spin_lock_irqsave(&clk_lock, flags);
300 __clk_disable(clk);
301 spin_unlock_irqrestore(&clk_lock, flags);
302 }
303 EXPORT_SYMBOL(clk_disable);
304
get_uart_rate(struct clk * clk)305 static unsigned long get_uart_rate(struct clk *clk)
306 {
307 unsigned long rate = clk_get_rate(clk->parent);
308 u32 value;
309
310 value = __raw_readl(EP93XX_SYSCON_PWRCNT);
311 if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD)
312 return rate;
313 else
314 return rate / 2;
315 }
316
clk_get_rate(struct clk * clk)317 unsigned long clk_get_rate(struct clk *clk)
318 {
319 if (clk->get_rate)
320 return clk->get_rate(clk);
321
322 return clk->rate;
323 }
324 EXPORT_SYMBOL(clk_get_rate);
325
set_keytchclk_rate(struct clk * clk,unsigned long rate)326 static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
327 {
328 u32 val;
329 u32 div_bit;
330
331 val = __raw_readl(clk->enable_reg);
332
333 /*
334 * The Key Matrix and ADC clocks are configured using the same
335 * System Controller register. The clock used will be either
336 * 1/4 or 1/16 the external clock rate depending on the
337 * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV
338 * bit being set or cleared.
339 */
340 div_bit = clk->enable_mask >> 15;
341
342 if (rate == EP93XX_KEYTCHCLK_DIV4)
343 val |= div_bit;
344 else if (rate == EP93XX_KEYTCHCLK_DIV16)
345 val &= ~div_bit;
346 else
347 return -EINVAL;
348
349 ep93xx_syscon_swlocked_write(val, clk->enable_reg);
350 clk->rate = rate;
351 return 0;
352 }
353
calc_clk_div(struct clk * clk,unsigned long rate,int * psel,int * esel,int * pdiv,int * div)354 static int calc_clk_div(struct clk *clk, unsigned long rate,
355 int *psel, int *esel, int *pdiv, int *div)
356 {
357 struct clk *mclk;
358 unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1;
359 int i, found = 0, __div = 0, __pdiv = 0;
360
361 /* Don't exceed the maximum rate */
362 max_rate = max3(clk_pll1.rate / 4, clk_pll2.rate / 4, clk_xtali.rate / 4);
363 rate = min(rate, max_rate);
364
365 /*
366 * Try the two pll's and the external clock
367 * Because the valid predividers are 2, 2.5 and 3, we multiply
368 * all the clocks by 2 to avoid floating point math.
369 *
370 * This is based on the algorithm in the ep93xx raster guide:
371 * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
372 *
373 */
374 for (i = 0; i < 3; i++) {
375 if (i == 0)
376 mclk = &clk_xtali;
377 else if (i == 1)
378 mclk = &clk_pll1;
379 else
380 mclk = &clk_pll2;
381 mclk_rate = mclk->rate * 2;
382
383 /* Try each predivider value */
384 for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
385 __div = mclk_rate / (rate * __pdiv);
386 if (__div < 2 || __div > 127)
387 continue;
388
389 actual_rate = mclk_rate / (__pdiv * __div);
390
391 if (!found || abs(actual_rate - rate) < rate_err) {
392 *pdiv = __pdiv - 3;
393 *div = __div;
394 *psel = (i == 2);
395 *esel = (i != 0);
396 clk->parent = mclk;
397 clk->rate = actual_rate;
398 rate_err = abs(actual_rate - rate);
399 found = 1;
400 }
401 }
402 }
403
404 if (!found)
405 return -EINVAL;
406
407 return 0;
408 }
409
set_div_rate(struct clk * clk,unsigned long rate)410 static int set_div_rate(struct clk *clk, unsigned long rate)
411 {
412 int err, psel = 0, esel = 0, pdiv = 0, div = 0;
413 u32 val;
414
415 err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div);
416 if (err)
417 return err;
418
419 /* Clear the esel, psel, pdiv and div bits */
420 val = __raw_readl(clk->enable_reg);
421 val &= ~0x7fff;
422
423 /* Set the new esel, psel, pdiv and div bits for the new clock rate */
424 val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
425 (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
426 (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
427 ep93xx_syscon_swlocked_write(val, clk->enable_reg);
428 return 0;
429 }
430
set_i2s_sclk_rate(struct clk * clk,unsigned long rate)431 static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate)
432 {
433 unsigned val = __raw_readl(clk->enable_reg);
434
435 if (rate == clk_i2s_mclk.rate / 2)
436 ep93xx_syscon_swlocked_write(val & ~EP93XX_I2SCLKDIV_SDIV,
437 clk->enable_reg);
438 else if (rate == clk_i2s_mclk.rate / 4)
439 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_SDIV,
440 clk->enable_reg);
441 else
442 return -EINVAL;
443
444 clk_i2s_sclk.rate = rate;
445 return 0;
446 }
447
set_i2s_lrclk_rate(struct clk * clk,unsigned long rate)448 static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate)
449 {
450 unsigned val = __raw_readl(clk->enable_reg) &
451 ~EP93XX_I2SCLKDIV_LRDIV_MASK;
452
453 if (rate == clk_i2s_sclk.rate / 32)
454 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV32,
455 clk->enable_reg);
456 else if (rate == clk_i2s_sclk.rate / 64)
457 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV64,
458 clk->enable_reg);
459 else if (rate == clk_i2s_sclk.rate / 128)
460 ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV128,
461 clk->enable_reg);
462 else
463 return -EINVAL;
464
465 clk_i2s_lrclk.rate = rate;
466 return 0;
467 }
468
clk_set_rate(struct clk * clk,unsigned long rate)469 int clk_set_rate(struct clk *clk, unsigned long rate)
470 {
471 if (clk->set_rate)
472 return clk->set_rate(clk, rate);
473
474 return -EINVAL;
475 }
476 EXPORT_SYMBOL(clk_set_rate);
477
478
479 static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
480 static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
481 static char pclk_divisors[] = { 1, 2, 4, 8 };
482
483 /*
484 * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
485 */
calc_pll_rate(u32 config_word)486 static unsigned long calc_pll_rate(u32 config_word)
487 {
488 unsigned long long rate;
489 int i;
490
491 rate = clk_xtali.rate;
492 rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
493 rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
494 do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
495 for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
496 rate >>= 1;
497
498 return (unsigned long)rate;
499 }
500
ep93xx_dma_clock_init(void)501 static void __init ep93xx_dma_clock_init(void)
502 {
503 clk_m2p0.rate = clk_h.rate;
504 clk_m2p1.rate = clk_h.rate;
505 clk_m2p2.rate = clk_h.rate;
506 clk_m2p3.rate = clk_h.rate;
507 clk_m2p4.rate = clk_h.rate;
508 clk_m2p5.rate = clk_h.rate;
509 clk_m2p6.rate = clk_h.rate;
510 clk_m2p7.rate = clk_h.rate;
511 clk_m2p8.rate = clk_h.rate;
512 clk_m2p9.rate = clk_h.rate;
513 clk_m2m0.rate = clk_h.rate;
514 clk_m2m1.rate = clk_h.rate;
515 }
516
ep93xx_clock_init(void)517 static int __init ep93xx_clock_init(void)
518 {
519 u32 value;
520
521 /* Determine the bootloader configured pll1 rate */
522 value = __raw_readl(EP93XX_SYSCON_CLKSET1);
523 if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1))
524 clk_pll1.rate = clk_xtali.rate;
525 else
526 clk_pll1.rate = calc_pll_rate(value);
527
528 /* Initialize the pll1 derived clocks */
529 clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
530 clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
531 clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
532 ep93xx_dma_clock_init();
533
534 /* Determine the bootloader configured pll2 rate */
535 value = __raw_readl(EP93XX_SYSCON_CLKSET2);
536 if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2))
537 clk_pll2.rate = clk_xtali.rate;
538 else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN)
539 clk_pll2.rate = calc_pll_rate(value);
540 else
541 clk_pll2.rate = 0;
542
543 /* Initialize the pll2 derived clocks */
544 clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
545
546 /*
547 * EP93xx SSP clock rate was doubled in version E2. For more information
548 * see:
549 * http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
550 */
551 if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2)
552 clk_spi.rate /= 2;
553
554 pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
555 clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
556 pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
557 clk_f.rate / 1000000, clk_h.rate / 1000000,
558 clk_p.rate / 1000000);
559
560 clkdev_add_table(clocks, ARRAY_SIZE(clocks));
561 return 0;
562 }
563 postcore_initcall(ep93xx_clock_init);
564