ACPI / video: Ignore BIOS initial backlight value for HP 250 G1
[linux-2.6.git] / drivers / clk / clk-vt8500.c
blob82306f5fb9c2497f82bcfafe403cdbc091b3dc66
1 /*
2 * Clock implementation for VIA/Wondermedia SoC's
3 * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <linux/io.h>
17 #include <linux/of.h>
18 #include <linux/slab.h>
19 #include <linux/bitops.h>
20 #include <linux/clkdev.h>
21 #include <linux/clk-provider.h>
23 /* All clocks share the same lock as none can be changed concurrently */
24 static DEFINE_SPINLOCK(_lock);
26 struct clk_device {
27 struct clk_hw hw;
28 void __iomem *div_reg;
29 unsigned int div_mask;
30 void __iomem *en_reg;
31 int en_bit;
32 spinlock_t *lock;
36 * Add new PLL_TYPE_x definitions here as required. Use the first known model
37 * to support the new type as the name.
38 * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
39 * vtwm_pll_set_rate() to handle the new PLL_TYPE_x
42 #define PLL_TYPE_VT8500 0
43 #define PLL_TYPE_WM8650 1
44 #define PLL_TYPE_WM8750 2
45 #define PLL_TYPE_WM8850 3
47 struct clk_pll {
48 struct clk_hw hw;
49 void __iomem *reg;
50 spinlock_t *lock;
51 int type;
54 static void __iomem *pmc_base;
56 #define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)
58 #define VT8500_PMC_BUSY_MASK 0x18
60 static void vt8500_pmc_wait_busy(void)
62 while (readl(pmc_base) & VT8500_PMC_BUSY_MASK)
63 cpu_relax();
66 static int vt8500_dclk_enable(struct clk_hw *hw)
68 struct clk_device *cdev = to_clk_device(hw);
69 u32 en_val;
70 unsigned long flags = 0;
72 spin_lock_irqsave(cdev->lock, flags);
74 en_val = readl(cdev->en_reg);
75 en_val |= BIT(cdev->en_bit);
76 writel(en_val, cdev->en_reg);
78 spin_unlock_irqrestore(cdev->lock, flags);
79 return 0;
82 static void vt8500_dclk_disable(struct clk_hw *hw)
84 struct clk_device *cdev = to_clk_device(hw);
85 u32 en_val;
86 unsigned long flags = 0;
88 spin_lock_irqsave(cdev->lock, flags);
90 en_val = readl(cdev->en_reg);
91 en_val &= ~BIT(cdev->en_bit);
92 writel(en_val, cdev->en_reg);
94 spin_unlock_irqrestore(cdev->lock, flags);
97 static int vt8500_dclk_is_enabled(struct clk_hw *hw)
99 struct clk_device *cdev = to_clk_device(hw);
100 u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit));
102 return en_val ? 1 : 0;
105 static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw,
106 unsigned long parent_rate)
108 struct clk_device *cdev = to_clk_device(hw);
109 u32 div = readl(cdev->div_reg) & cdev->div_mask;
111 /* Special case for SDMMC devices */
112 if ((cdev->div_mask == 0x3F) && (div & BIT(5)))
113 div = 64 * (div & 0x1f);
115 /* div == 0 is actually the highest divisor */
116 if (div == 0)
117 div = (cdev->div_mask + 1);
119 return parent_rate / div;
122 static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
123 unsigned long *prate)
125 struct clk_device *cdev = to_clk_device(hw);
126 u32 divisor;
128 if (rate == 0)
129 return 0;
131 divisor = *prate / rate;
133 /* If prate / rate would be decimal, incr the divisor */
134 if (rate * divisor < *prate)
135 divisor++;
138 * If this is a request for SDMMC we have to adjust the divisor
139 * when >31 to use the fixed predivisor
141 if ((cdev->div_mask == 0x3F) && (divisor > 31)) {
142 divisor = 64 * ((divisor / 64) + 1);
145 return *prate / divisor;
148 static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
149 unsigned long parent_rate)
151 struct clk_device *cdev = to_clk_device(hw);
152 u32 divisor;
153 unsigned long flags = 0;
155 if (rate == 0)
156 return 0;
158 divisor = parent_rate / rate;
160 if (divisor == cdev->div_mask + 1)
161 divisor = 0;
163 /* SDMMC mask may need to be corrected before testing if its valid */
164 if ((cdev->div_mask == 0x3F) && (divisor > 31)) {
166 * Bit 5 is a fixed /64 predivisor. If the requested divisor
167 * is >31 then correct for the fixed divisor being required.
169 divisor = 0x20 + (divisor / 64);
172 if (divisor > cdev->div_mask) {
173 pr_err("%s: invalid divisor for clock\n", __func__);
174 return -EINVAL;
177 spin_lock_irqsave(cdev->lock, flags);
179 vt8500_pmc_wait_busy();
180 writel(divisor, cdev->div_reg);
181 vt8500_pmc_wait_busy();
183 spin_unlock_irqrestore(cdev->lock, flags);
185 return 0;
189 static const struct clk_ops vt8500_gated_clk_ops = {
190 .enable = vt8500_dclk_enable,
191 .disable = vt8500_dclk_disable,
192 .is_enabled = vt8500_dclk_is_enabled,
195 static const struct clk_ops vt8500_divisor_clk_ops = {
196 .round_rate = vt8500_dclk_round_rate,
197 .set_rate = vt8500_dclk_set_rate,
198 .recalc_rate = vt8500_dclk_recalc_rate,
201 static const struct clk_ops vt8500_gated_divisor_clk_ops = {
202 .enable = vt8500_dclk_enable,
203 .disable = vt8500_dclk_disable,
204 .is_enabled = vt8500_dclk_is_enabled,
205 .round_rate = vt8500_dclk_round_rate,
206 .set_rate = vt8500_dclk_set_rate,
207 .recalc_rate = vt8500_dclk_recalc_rate,
210 #define CLK_INIT_GATED BIT(0)
211 #define CLK_INIT_DIVISOR BIT(1)
212 #define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED)
214 static __init void vtwm_device_clk_init(struct device_node *node)
216 u32 en_reg, div_reg;
217 struct clk *clk;
218 struct clk_device *dev_clk;
219 const char *clk_name = node->name;
220 const char *parent_name;
221 struct clk_init_data init;
222 int rc;
223 int clk_init_flags = 0;
225 dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
226 if (WARN_ON(!dev_clk))
227 return;
229 dev_clk->lock = &_lock;
231 rc = of_property_read_u32(node, "enable-reg", &en_reg);
232 if (!rc) {
233 dev_clk->en_reg = pmc_base + en_reg;
234 rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit);
235 if (rc) {
236 pr_err("%s: enable-bit property required for gated clock\n",
237 __func__);
238 return;
240 clk_init_flags |= CLK_INIT_GATED;
243 rc = of_property_read_u32(node, "divisor-reg", &div_reg);
244 if (!rc) {
245 dev_clk->div_reg = pmc_base + div_reg;
247 * use 0x1f as the default mask since it covers
248 * almost all the clocks and reduces dts properties
250 dev_clk->div_mask = 0x1f;
252 of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask);
253 clk_init_flags |= CLK_INIT_DIVISOR;
256 of_property_read_string(node, "clock-output-names", &clk_name);
258 switch (clk_init_flags) {
259 case CLK_INIT_GATED:
260 init.ops = &vt8500_gated_clk_ops;
261 break;
262 case CLK_INIT_DIVISOR:
263 init.ops = &vt8500_divisor_clk_ops;
264 break;
265 case CLK_INIT_GATED_DIVISOR:
266 init.ops = &vt8500_gated_divisor_clk_ops;
267 break;
268 default:
269 pr_err("%s: Invalid clock description in device tree\n",
270 __func__);
271 kfree(dev_clk);
272 return;
275 init.name = clk_name;
276 init.flags = 0;
277 parent_name = of_clk_get_parent_name(node, 0);
278 init.parent_names = &parent_name;
279 init.num_parents = 1;
281 dev_clk->hw.init = &init;
283 clk = clk_register(NULL, &dev_clk->hw);
284 if (WARN_ON(IS_ERR(clk))) {
285 kfree(dev_clk);
286 return;
288 rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
289 clk_register_clkdev(clk, clk_name, NULL);
291 CLK_OF_DECLARE(vt8500_device, "via,vt8500-device-clock", vtwm_device_clk_init);
293 /* PLL clock related functions */
295 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
297 /* Helper macros for PLL_VT8500 */
298 #define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
299 #define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)
301 #define VT8500_BITS_TO_FREQ(r, m, d) \
302 ((r / d) * m)
304 #define VT8500_BITS_TO_VAL(m, d) \
305 ((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))
307 /* Helper macros for PLL_WM8650 */
308 #define WM8650_PLL_MUL(x) (x & 0x3FF)
309 #define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))
311 #define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
312 (r * m / (d1 * (1 << d2)))
314 #define WM8650_BITS_TO_VAL(m, d1, d2) \
315 ((d2 << 13) | (d1 << 10) | (m & 0x3FF))
317 /* Helper macros for PLL_WM8750 */
318 #define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1)
319 #define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7)))
321 #define WM8750_BITS_TO_FREQ(r, m, d1, d2) \
322 (r * (m+1) / ((d1+1) * (1 << d2)))
324 #define WM8750_BITS_TO_VAL(f, m, d1, d2) \
325 ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2)
327 /* Helper macros for PLL_WM8850 */
328 #define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2)
329 #define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3)))
331 #define WM8850_BITS_TO_FREQ(r, m, d1, d2) \
332 (r * ((m + 1) * 2) / ((d1+1) * (1 << d2)))
334 #define WM8850_BITS_TO_VAL(m, d1, d2) \
335 ((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2)
337 static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate,
338 u32 *multiplier, u32 *prediv)
340 unsigned long tclk;
342 /* sanity check */
343 if ((rate < parent_rate * 4) || (rate > parent_rate * 62)) {
344 pr_err("%s: requested rate out of range\n", __func__);
345 *multiplier = 0;
346 *prediv = 1;
347 return;
349 if (rate <= parent_rate * 31)
350 /* use the prediv to double the resolution */
351 *prediv = 2;
352 else
353 *prediv = 1;
355 *multiplier = rate / (parent_rate / *prediv);
356 tclk = (parent_rate / *prediv) * *multiplier;
358 if (tclk != rate)
359 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__,
360 rate, tclk);
363 static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate,
364 u32 *multiplier, u32 *divisor1, u32 *divisor2)
366 u32 mul, div1, div2;
367 u32 best_mul, best_div1, best_div2;
368 unsigned long tclk, rate_err, best_err;
370 best_err = (unsigned long)-1;
372 /* Find the closest match (lower or equal to requested) */
373 for (div1 = 5; div1 >= 3; div1--)
374 for (div2 = 3; div2 >= 0; div2--)
375 for (mul = 3; mul <= 1023; mul++) {
376 tclk = parent_rate * mul / (div1 * (1 << div2));
377 if (tclk > rate)
378 continue;
379 /* error will always be +ve */
380 rate_err = rate - tclk;
381 if (rate_err == 0) {
382 *multiplier = mul;
383 *divisor1 = div1;
384 *divisor2 = div2;
385 return;
388 if (rate_err < best_err) {
389 best_err = rate_err;
390 best_mul = mul;
391 best_div1 = div1;
392 best_div2 = div2;
396 /* if we got here, it wasn't an exact match */
397 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
398 rate - best_err);
399 *multiplier = best_mul;
400 *divisor1 = best_div1;
401 *divisor2 = best_div2;
404 static u32 wm8750_get_filter(u32 parent_rate, u32 divisor1)
406 /* calculate frequency (MHz) after pre-divisor */
407 u32 freq = (parent_rate / 1000000) / (divisor1 + 1);
409 if ((freq < 10) || (freq > 200))
410 pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n",
411 __func__, freq);
413 if (freq >= 166)
414 return 7;
415 else if (freq >= 104)
416 return 6;
417 else if (freq >= 65)
418 return 5;
419 else if (freq >= 42)
420 return 4;
421 else if (freq >= 26)
422 return 3;
423 else if (freq >= 16)
424 return 2;
425 else if (freq >= 10)
426 return 1;
428 return 0;
431 static void wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate,
432 u32 *filter, u32 *multiplier, u32 *divisor1, u32 *divisor2)
434 u32 mul, div1, div2;
435 u32 best_mul, best_div1, best_div2;
436 unsigned long tclk, rate_err, best_err;
438 best_err = (unsigned long)-1;
440 /* Find the closest match (lower or equal to requested) */
441 for (div1 = 1; div1 >= 0; div1--)
442 for (div2 = 7; div2 >= 0; div2--)
443 for (mul = 0; mul <= 255; mul++) {
444 tclk = parent_rate * (mul + 1) / ((div1 + 1) * (1 << div2));
445 if (tclk > rate)
446 continue;
447 /* error will always be +ve */
448 rate_err = rate - tclk;
449 if (rate_err == 0) {
450 *filter = wm8750_get_filter(parent_rate, div1);
451 *multiplier = mul;
452 *divisor1 = div1;
453 *divisor2 = div2;
454 return;
457 if (rate_err < best_err) {
458 best_err = rate_err;
459 best_mul = mul;
460 best_div1 = div1;
461 best_div2 = div2;
465 /* if we got here, it wasn't an exact match */
466 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
467 rate - best_err);
469 *filter = wm8750_get_filter(parent_rate, best_div1);
470 *multiplier = best_mul;
471 *divisor1 = best_div1;
472 *divisor2 = best_div2;
475 static void wm8850_find_pll_bits(unsigned long rate, unsigned long parent_rate,
476 u32 *multiplier, u32 *divisor1, u32 *divisor2)
478 u32 mul, div1, div2;
479 u32 best_mul, best_div1, best_div2;
480 unsigned long tclk, rate_err, best_err;
482 best_err = (unsigned long)-1;
484 /* Find the closest match (lower or equal to requested) */
485 for (div1 = 1; div1 >= 0; div1--)
486 for (div2 = 3; div2 >= 0; div2--)
487 for (mul = 0; mul <= 127; mul++) {
488 tclk = parent_rate * ((mul + 1) * 2) /
489 ((div1 + 1) * (1 << div2));
490 if (tclk > rate)
491 continue;
492 /* error will always be +ve */
493 rate_err = rate - tclk;
494 if (rate_err == 0) {
495 *multiplier = mul;
496 *divisor1 = div1;
497 *divisor2 = div2;
498 return;
501 if (rate_err < best_err) {
502 best_err = rate_err;
503 best_mul = mul;
504 best_div1 = div1;
505 best_div2 = div2;
509 /* if we got here, it wasn't an exact match */
510 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
511 rate - best_err);
513 *multiplier = best_mul;
514 *divisor1 = best_div1;
515 *divisor2 = best_div2;
518 static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate,
519 unsigned long parent_rate)
521 struct clk_pll *pll = to_clk_pll(hw);
522 u32 filter, mul, div1, div2;
523 u32 pll_val;
524 unsigned long flags = 0;
526 /* sanity check */
528 switch (pll->type) {
529 case PLL_TYPE_VT8500:
530 vt8500_find_pll_bits(rate, parent_rate, &mul, &div1);
531 pll_val = VT8500_BITS_TO_VAL(mul, div1);
532 break;
533 case PLL_TYPE_WM8650:
534 wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
535 pll_val = WM8650_BITS_TO_VAL(mul, div1, div2);
536 break;
537 case PLL_TYPE_WM8750:
538 wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2);
539 pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2);
540 break;
541 case PLL_TYPE_WM8850:
542 wm8850_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
543 pll_val = WM8850_BITS_TO_VAL(mul, div1, div2);
544 break;
545 default:
546 pr_err("%s: invalid pll type\n", __func__);
547 return 0;
550 spin_lock_irqsave(pll->lock, flags);
552 vt8500_pmc_wait_busy();
553 writel(pll_val, pll->reg);
554 vt8500_pmc_wait_busy();
556 spin_unlock_irqrestore(pll->lock, flags);
558 return 0;
561 static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate,
562 unsigned long *prate)
564 struct clk_pll *pll = to_clk_pll(hw);
565 u32 filter, mul, div1, div2;
566 long round_rate;
568 switch (pll->type) {
569 case PLL_TYPE_VT8500:
570 vt8500_find_pll_bits(rate, *prate, &mul, &div1);
571 round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1);
572 break;
573 case PLL_TYPE_WM8650:
574 wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2);
575 round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2);
576 break;
577 case PLL_TYPE_WM8750:
578 wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2);
579 round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2);
580 break;
581 case PLL_TYPE_WM8850:
582 wm8850_find_pll_bits(rate, *prate, &mul, &div1, &div2);
583 round_rate = WM8850_BITS_TO_FREQ(*prate, mul, div1, div2);
584 break;
585 default:
586 round_rate = 0;
589 return round_rate;
592 static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw,
593 unsigned long parent_rate)
595 struct clk_pll *pll = to_clk_pll(hw);
596 u32 pll_val = readl(pll->reg);
597 unsigned long pll_freq;
599 switch (pll->type) {
600 case PLL_TYPE_VT8500:
601 pll_freq = parent_rate * VT8500_PLL_MUL(pll_val);
602 pll_freq /= VT8500_PLL_DIV(pll_val);
603 break;
604 case PLL_TYPE_WM8650:
605 pll_freq = parent_rate * WM8650_PLL_MUL(pll_val);
606 pll_freq /= WM8650_PLL_DIV(pll_val);
607 break;
608 case PLL_TYPE_WM8750:
609 pll_freq = parent_rate * WM8750_PLL_MUL(pll_val);
610 pll_freq /= WM8750_PLL_DIV(pll_val);
611 break;
612 case PLL_TYPE_WM8850:
613 pll_freq = parent_rate * WM8850_PLL_MUL(pll_val);
614 pll_freq /= WM8850_PLL_DIV(pll_val);
615 break;
616 default:
617 pll_freq = 0;
620 return pll_freq;
623 const struct clk_ops vtwm_pll_ops = {
624 .round_rate = vtwm_pll_round_rate,
625 .set_rate = vtwm_pll_set_rate,
626 .recalc_rate = vtwm_pll_recalc_rate,
629 static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type)
631 u32 reg;
632 struct clk *clk;
633 struct clk_pll *pll_clk;
634 const char *clk_name = node->name;
635 const char *parent_name;
636 struct clk_init_data init;
637 int rc;
639 rc = of_property_read_u32(node, "reg", &reg);
640 if (WARN_ON(rc))
641 return;
643 pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
644 if (WARN_ON(!pll_clk))
645 return;
647 pll_clk->reg = pmc_base + reg;
648 pll_clk->lock = &_lock;
649 pll_clk->type = pll_type;
651 of_property_read_string(node, "clock-output-names", &clk_name);
653 init.name = clk_name;
654 init.ops = &vtwm_pll_ops;
655 init.flags = 0;
656 parent_name = of_clk_get_parent_name(node, 0);
657 init.parent_names = &parent_name;
658 init.num_parents = 1;
660 pll_clk->hw.init = &init;
662 clk = clk_register(NULL, &pll_clk->hw);
663 if (WARN_ON(IS_ERR(clk))) {
664 kfree(pll_clk);
665 return;
667 rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
668 clk_register_clkdev(clk, clk_name, NULL);
672 /* Wrappers for initialization functions */
674 static void __init vt8500_pll_init(struct device_node *node)
676 vtwm_pll_clk_init(node, PLL_TYPE_VT8500);
678 CLK_OF_DECLARE(vt8500_pll, "via,vt8500-pll-clock", vt8500_pll_init);
680 static void __init wm8650_pll_init(struct device_node *node)
682 vtwm_pll_clk_init(node, PLL_TYPE_WM8650);
684 CLK_OF_DECLARE(wm8650_pll, "wm,wm8650-pll-clock", wm8650_pll_init);
686 static void __init wm8750_pll_init(struct device_node *node)
688 vtwm_pll_clk_init(node, PLL_TYPE_WM8750);
690 CLK_OF_DECLARE(wm8750_pll, "wm,wm8750-pll-clock", wm8750_pll_init);
692 static void __init wm8850_pll_init(struct device_node *node)
694 vtwm_pll_clk_init(node, PLL_TYPE_WM8850);
696 CLK_OF_DECLARE(wm8850_pll, "wm,wm8850-pll-clock", wm8850_pll_init);
698 void __init vtwm_clk_init(void __iomem *base)
700 if (!base)
701 return;
703 pmc_base = base;
705 of_clk_init(NULL);