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.
18 #include <linux/of_address.h>
19 #include <linux/slab.h>
20 #include <linux/bitops.h>
21 #include <linux/clkdev.h>
22 #include <linux/clk-provider.h>
24 #define LEGACY_PMC_BASE 0xD8130000
26 /* All clocks share the same lock as none can be changed concurrently */
27 static DEFINE_SPINLOCK(_lock
);
31 void __iomem
*div_reg
;
32 unsigned int div_mask
;
39 * Add new PLL_TYPE_x definitions here as required. Use the first known model
40 * to support the new type as the name.
41 * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
42 * vtwm_pll_set_rate() to handle the new PLL_TYPE_x
45 #define PLL_TYPE_VT8500 0
46 #define PLL_TYPE_WM8650 1
47 #define PLL_TYPE_WM8750 2
48 #define PLL_TYPE_WM8850 3
57 static void __iomem
*pmc_base
;
59 static __init
void vtwm_set_pmc_base(void)
61 struct device_node
*np
=
62 of_find_compatible_node(NULL
, NULL
, "via,vt8500-pmc");
65 pmc_base
= of_iomap(np
, 0);
67 pmc_base
= ioremap(LEGACY_PMC_BASE
, 0x1000);
71 pr_err("%s:of_iomap(pmc) failed\n", __func__
);
74 #define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)
76 #define VT8500_PMC_BUSY_MASK 0x18
78 static void vt8500_pmc_wait_busy(void)
80 while (readl(pmc_base
) & VT8500_PMC_BUSY_MASK
)
84 static int vt8500_dclk_enable(struct clk_hw
*hw
)
86 struct clk_device
*cdev
= to_clk_device(hw
);
88 unsigned long flags
= 0;
90 spin_lock_irqsave(cdev
->lock
, flags
);
92 en_val
= readl(cdev
->en_reg
);
93 en_val
|= BIT(cdev
->en_bit
);
94 writel(en_val
, cdev
->en_reg
);
96 spin_unlock_irqrestore(cdev
->lock
, flags
);
100 static void vt8500_dclk_disable(struct clk_hw
*hw
)
102 struct clk_device
*cdev
= to_clk_device(hw
);
104 unsigned long flags
= 0;
106 spin_lock_irqsave(cdev
->lock
, flags
);
108 en_val
= readl(cdev
->en_reg
);
109 en_val
&= ~BIT(cdev
->en_bit
);
110 writel(en_val
, cdev
->en_reg
);
112 spin_unlock_irqrestore(cdev
->lock
, flags
);
115 static int vt8500_dclk_is_enabled(struct clk_hw
*hw
)
117 struct clk_device
*cdev
= to_clk_device(hw
);
118 u32 en_val
= (readl(cdev
->en_reg
) & BIT(cdev
->en_bit
));
120 return en_val
? 1 : 0;
123 static unsigned long vt8500_dclk_recalc_rate(struct clk_hw
*hw
,
124 unsigned long parent_rate
)
126 struct clk_device
*cdev
= to_clk_device(hw
);
127 u32 div
= readl(cdev
->div_reg
) & cdev
->div_mask
;
129 /* Special case for SDMMC devices */
130 if ((cdev
->div_mask
== 0x3F) && (div
& BIT(5)))
131 div
= 64 * (div
& 0x1f);
133 /* div == 0 is actually the highest divisor */
135 div
= (cdev
->div_mask
+ 1);
137 return parent_rate
/ div
;
140 static long vt8500_dclk_round_rate(struct clk_hw
*hw
, unsigned long rate
,
141 unsigned long *prate
)
143 struct clk_device
*cdev
= to_clk_device(hw
);
149 divisor
= *prate
/ rate
;
151 /* If prate / rate would be decimal, incr the divisor */
152 if (rate
* divisor
< *prate
)
156 * If this is a request for SDMMC we have to adjust the divisor
157 * when >31 to use the fixed predivisor
159 if ((cdev
->div_mask
== 0x3F) && (divisor
> 31)) {
160 divisor
= 64 * ((divisor
/ 64) + 1);
163 return *prate
/ divisor
;
166 static int vt8500_dclk_set_rate(struct clk_hw
*hw
, unsigned long rate
,
167 unsigned long parent_rate
)
169 struct clk_device
*cdev
= to_clk_device(hw
);
171 unsigned long flags
= 0;
176 divisor
= parent_rate
/ rate
;
178 if (divisor
== cdev
->div_mask
+ 1)
181 /* SDMMC mask may need to be corrected before testing if its valid */
182 if ((cdev
->div_mask
== 0x3F) && (divisor
> 31)) {
184 * Bit 5 is a fixed /64 predivisor. If the requested divisor
185 * is >31 then correct for the fixed divisor being required.
187 divisor
= 0x20 + (divisor
/ 64);
190 if (divisor
> cdev
->div_mask
) {
191 pr_err("%s: invalid divisor for clock\n", __func__
);
195 spin_lock_irqsave(cdev
->lock
, flags
);
197 vt8500_pmc_wait_busy();
198 writel(divisor
, cdev
->div_reg
);
199 vt8500_pmc_wait_busy();
201 spin_unlock_irqrestore(cdev
->lock
, flags
);
207 static const struct clk_ops vt8500_gated_clk_ops
= {
208 .enable
= vt8500_dclk_enable
,
209 .disable
= vt8500_dclk_disable
,
210 .is_enabled
= vt8500_dclk_is_enabled
,
213 static const struct clk_ops vt8500_divisor_clk_ops
= {
214 .round_rate
= vt8500_dclk_round_rate
,
215 .set_rate
= vt8500_dclk_set_rate
,
216 .recalc_rate
= vt8500_dclk_recalc_rate
,
219 static const struct clk_ops vt8500_gated_divisor_clk_ops
= {
220 .enable
= vt8500_dclk_enable
,
221 .disable
= vt8500_dclk_disable
,
222 .is_enabled
= vt8500_dclk_is_enabled
,
223 .round_rate
= vt8500_dclk_round_rate
,
224 .set_rate
= vt8500_dclk_set_rate
,
225 .recalc_rate
= vt8500_dclk_recalc_rate
,
228 #define CLK_INIT_GATED BIT(0)
229 #define CLK_INIT_DIVISOR BIT(1)
230 #define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED)
232 static __init
void vtwm_device_clk_init(struct device_node
*node
)
236 struct clk_device
*dev_clk
;
237 const char *clk_name
= node
->name
;
238 const char *parent_name
;
239 struct clk_init_data init
;
241 int clk_init_flags
= 0;
246 dev_clk
= kzalloc(sizeof(*dev_clk
), GFP_KERNEL
);
247 if (WARN_ON(!dev_clk
))
250 dev_clk
->lock
= &_lock
;
252 rc
= of_property_read_u32(node
, "enable-reg", &en_reg
);
254 dev_clk
->en_reg
= pmc_base
+ en_reg
;
255 rc
= of_property_read_u32(node
, "enable-bit", &dev_clk
->en_bit
);
257 pr_err("%s: enable-bit property required for gated clock\n",
261 clk_init_flags
|= CLK_INIT_GATED
;
264 rc
= of_property_read_u32(node
, "divisor-reg", &div_reg
);
266 dev_clk
->div_reg
= pmc_base
+ div_reg
;
268 * use 0x1f as the default mask since it covers
269 * almost all the clocks and reduces dts properties
271 dev_clk
->div_mask
= 0x1f;
273 of_property_read_u32(node
, "divisor-mask", &dev_clk
->div_mask
);
274 clk_init_flags
|= CLK_INIT_DIVISOR
;
277 of_property_read_string(node
, "clock-output-names", &clk_name
);
279 switch (clk_init_flags
) {
281 init
.ops
= &vt8500_gated_clk_ops
;
283 case CLK_INIT_DIVISOR
:
284 init
.ops
= &vt8500_divisor_clk_ops
;
286 case CLK_INIT_GATED_DIVISOR
:
287 init
.ops
= &vt8500_gated_divisor_clk_ops
;
290 pr_err("%s: Invalid clock description in device tree\n",
296 init
.name
= clk_name
;
298 parent_name
= of_clk_get_parent_name(node
, 0);
299 init
.parent_names
= &parent_name
;
300 init
.num_parents
= 1;
302 dev_clk
->hw
.init
= &init
;
305 rc
= clk_hw_register(NULL
, hw
);
310 rc
= of_clk_add_hw_provider(node
, of_clk_hw_simple_get
, hw
);
311 clk_hw_register_clkdev(hw
, clk_name
, NULL
);
313 CLK_OF_DECLARE(vt8500_device
, "via,vt8500-device-clock", vtwm_device_clk_init
);
315 /* PLL clock related functions */
317 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
319 /* Helper macros for PLL_VT8500 */
320 #define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
321 #define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)
323 #define VT8500_BITS_TO_FREQ(r, m, d) \
326 #define VT8500_BITS_TO_VAL(m, d) \
327 ((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))
329 /* Helper macros for PLL_WM8650 */
330 #define WM8650_PLL_MUL(x) (x & 0x3FF)
331 #define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))
333 #define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
334 (r * m / (d1 * (1 << d2)))
336 #define WM8650_BITS_TO_VAL(m, d1, d2) \
337 ((d2 << 13) | (d1 << 10) | (m & 0x3FF))
339 /* Helper macros for PLL_WM8750 */
340 #define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1)
341 #define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7)))
343 #define WM8750_BITS_TO_FREQ(r, m, d1, d2) \
344 (r * (m+1) / ((d1+1) * (1 << d2)))
346 #define WM8750_BITS_TO_VAL(f, m, d1, d2) \
347 ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2)
349 /* Helper macros for PLL_WM8850 */
350 #define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2)
351 #define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3)))
353 #define WM8850_BITS_TO_FREQ(r, m, d1, d2) \
354 (r * ((m + 1) * 2) / ((d1+1) * (1 << d2)))
356 #define WM8850_BITS_TO_VAL(m, d1, d2) \
357 ((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2)
359 static int vt8500_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
360 u32
*multiplier
, u32
*prediv
)
365 if ((rate
< parent_rate
* 4) || (rate
> parent_rate
* 62)) {
366 pr_err("%s: requested rate out of range\n", __func__
);
371 if (rate
<= parent_rate
* 31)
372 /* use the prediv to double the resolution */
377 *multiplier
= rate
/ (parent_rate
/ *prediv
);
378 tclk
= (parent_rate
/ *prediv
) * *multiplier
;
381 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
,
388 * M * parent [O1] => / P [O2] => / D [O3]
389 * Where O1 is 900MHz...3GHz;
390 * O2 is 600MHz >= (M * parent) / P >= 300MHz;
391 * M is 36...120 [25MHz parent]; D is 1 or 2 or 4 or 8.
392 * Possible ranges (O3):
393 * D = 8: 37,5MHz...75MHz
394 * D = 4: 75MHz...150MHz
395 * D = 2: 150MHz...300MHz
396 * D = 1: 300MHz...600MHz
398 static int wm8650_find_pll_bits(unsigned long rate
,
399 unsigned long parent_rate
, u32
*multiplier
, u32
*divisor1
,
402 unsigned long O1
, min_err
, rate_err
;
404 if (!parent_rate
|| (rate
< 37500000) || (rate
> 600000000))
407 *divisor2
= rate
<= 75000000 ? 3 : rate
<= 150000000 ? 2 :
408 rate
<= 300000000 ? 1 : 0;
410 * Divisor P cannot be calculated. Test all divisors and find where M
411 * will be as close as possible to the requested rate.
414 for (*divisor1
= 5; *divisor1
>= 3; (*divisor1
)--) {
415 O1
= rate
* *divisor1
* (1 << (*divisor2
));
416 rate_err
= O1
% parent_rate
;
417 if (rate_err
< min_err
) {
418 *multiplier
= O1
/ parent_rate
;
426 if ((*multiplier
< 3) || (*multiplier
> 1023))
429 pr_warn("%s: rate error is %lu\n", __func__
, min_err
);
434 static u32
wm8750_get_filter(u32 parent_rate
, u32 divisor1
)
436 /* calculate frequency (MHz) after pre-divisor */
437 u32 freq
= (parent_rate
/ 1000000) / (divisor1
+ 1);
439 if ((freq
< 10) || (freq
> 200))
440 pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n",
445 else if (freq
>= 104)
461 static int wm8750_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
462 u32
*filter
, u32
*multiplier
, u32
*divisor1
, u32
*divisor2
)
466 unsigned long tclk
, rate_err
, best_err
;
468 best_err
= (unsigned long)-1;
470 /* Find the closest match (lower or equal to requested) */
471 for (div1
= 1; div1
>= 0; div1
--)
472 for (div2
= 7; div2
>= 0; div2
--)
473 for (mul
= 0; mul
<= 255; mul
++) {
474 tclk
= parent_rate
* (mul
+ 1) / ((div1
+ 1) * (1 << div2
));
477 /* error will always be +ve */
478 rate_err
= rate
- tclk
;
480 *filter
= wm8750_get_filter(parent_rate
, div1
);
487 if (rate_err
< best_err
) {
495 if (best_err
== (unsigned long)-1) {
496 pr_warn("%s: impossible rate %lu\n", __func__
, rate
);
500 /* if we got here, it wasn't an exact match */
501 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
, rate
,
504 *filter
= wm8750_get_filter(parent_rate
, *divisor1
);
509 static int wm8850_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
510 u32
*multiplier
, u32
*divisor1
, u32
*divisor2
)
514 unsigned long tclk
, rate_err
, best_err
;
516 best_err
= (unsigned long)-1;
518 /* Find the closest match (lower or equal to requested) */
519 for (div1
= 1; div1
>= 0; div1
--)
520 for (div2
= 3; div2
>= 0; div2
--)
521 for (mul
= 0; mul
<= 127; mul
++) {
522 tclk
= parent_rate
* ((mul
+ 1) * 2) /
523 ((div1
+ 1) * (1 << div2
));
526 /* error will always be +ve */
527 rate_err
= rate
- tclk
;
535 if (rate_err
< best_err
) {
543 if (best_err
== (unsigned long)-1) {
544 pr_warn("%s: impossible rate %lu\n", __func__
, rate
);
548 /* if we got here, it wasn't an exact match */
549 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
, rate
,
555 static int vtwm_pll_set_rate(struct clk_hw
*hw
, unsigned long rate
,
556 unsigned long parent_rate
)
558 struct clk_pll
*pll
= to_clk_pll(hw
);
559 u32 filter
, mul
, div1
, div2
;
561 unsigned long flags
= 0;
567 case PLL_TYPE_VT8500
:
568 ret
= vt8500_find_pll_bits(rate
, parent_rate
, &mul
, &div1
);
570 pll_val
= VT8500_BITS_TO_VAL(mul
, div1
);
572 case PLL_TYPE_WM8650
:
573 ret
= wm8650_find_pll_bits(rate
, parent_rate
, &mul
, &div1
, &div2
);
575 pll_val
= WM8650_BITS_TO_VAL(mul
, div1
, div2
);
577 case PLL_TYPE_WM8750
:
578 ret
= wm8750_find_pll_bits(rate
, parent_rate
, &filter
, &mul
, &div1
, &div2
);
580 pll_val
= WM8750_BITS_TO_VAL(filter
, mul
, div1
, div2
);
582 case PLL_TYPE_WM8850
:
583 ret
= wm8850_find_pll_bits(rate
, parent_rate
, &mul
, &div1
, &div2
);
585 pll_val
= WM8850_BITS_TO_VAL(mul
, div1
, div2
);
588 pr_err("%s: invalid pll type\n", __func__
);
595 spin_lock_irqsave(pll
->lock
, flags
);
597 vt8500_pmc_wait_busy();
598 writel(pll_val
, pll
->reg
);
599 vt8500_pmc_wait_busy();
601 spin_unlock_irqrestore(pll
->lock
, flags
);
606 static long vtwm_pll_round_rate(struct clk_hw
*hw
, unsigned long rate
,
607 unsigned long *prate
)
609 struct clk_pll
*pll
= to_clk_pll(hw
);
610 u32 filter
, mul
, div1
, div2
;
615 case PLL_TYPE_VT8500
:
616 ret
= vt8500_find_pll_bits(rate
, *prate
, &mul
, &div1
);
618 round_rate
= VT8500_BITS_TO_FREQ(*prate
, mul
, div1
);
620 case PLL_TYPE_WM8650
:
621 ret
= wm8650_find_pll_bits(rate
, *prate
, &mul
, &div1
, &div2
);
623 round_rate
= WM8650_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
625 case PLL_TYPE_WM8750
:
626 ret
= wm8750_find_pll_bits(rate
, *prate
, &filter
, &mul
, &div1
, &div2
);
628 round_rate
= WM8750_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
630 case PLL_TYPE_WM8850
:
631 ret
= wm8850_find_pll_bits(rate
, *prate
, &mul
, &div1
, &div2
);
633 round_rate
= WM8850_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
645 static unsigned long vtwm_pll_recalc_rate(struct clk_hw
*hw
,
646 unsigned long parent_rate
)
648 struct clk_pll
*pll
= to_clk_pll(hw
);
649 u32 pll_val
= readl(pll
->reg
);
650 unsigned long pll_freq
;
653 case PLL_TYPE_VT8500
:
654 pll_freq
= parent_rate
* VT8500_PLL_MUL(pll_val
);
655 pll_freq
/= VT8500_PLL_DIV(pll_val
);
657 case PLL_TYPE_WM8650
:
658 pll_freq
= parent_rate
* WM8650_PLL_MUL(pll_val
);
659 pll_freq
/= WM8650_PLL_DIV(pll_val
);
661 case PLL_TYPE_WM8750
:
662 pll_freq
= parent_rate
* WM8750_PLL_MUL(pll_val
);
663 pll_freq
/= WM8750_PLL_DIV(pll_val
);
665 case PLL_TYPE_WM8850
:
666 pll_freq
= parent_rate
* WM8850_PLL_MUL(pll_val
);
667 pll_freq
/= WM8850_PLL_DIV(pll_val
);
676 static const struct clk_ops vtwm_pll_ops
= {
677 .round_rate
= vtwm_pll_round_rate
,
678 .set_rate
= vtwm_pll_set_rate
,
679 .recalc_rate
= vtwm_pll_recalc_rate
,
682 static __init
void vtwm_pll_clk_init(struct device_node
*node
, int pll_type
)
686 struct clk_pll
*pll_clk
;
687 const char *clk_name
= node
->name
;
688 const char *parent_name
;
689 struct clk_init_data init
;
695 rc
= of_property_read_u32(node
, "reg", ®
);
699 pll_clk
= kzalloc(sizeof(*pll_clk
), GFP_KERNEL
);
700 if (WARN_ON(!pll_clk
))
703 pll_clk
->reg
= pmc_base
+ reg
;
704 pll_clk
->lock
= &_lock
;
705 pll_clk
->type
= pll_type
;
707 of_property_read_string(node
, "clock-output-names", &clk_name
);
709 init
.name
= clk_name
;
710 init
.ops
= &vtwm_pll_ops
;
712 parent_name
= of_clk_get_parent_name(node
, 0);
713 init
.parent_names
= &parent_name
;
714 init
.num_parents
= 1;
716 pll_clk
->hw
.init
= &init
;
719 rc
= clk_hw_register(NULL
, &pll_clk
->hw
);
724 rc
= of_clk_add_hw_provider(node
, of_clk_hw_simple_get
, hw
);
725 clk_hw_register_clkdev(hw
, clk_name
, NULL
);
729 /* Wrappers for initialization functions */
731 static void __init
vt8500_pll_init(struct device_node
*node
)
733 vtwm_pll_clk_init(node
, PLL_TYPE_VT8500
);
735 CLK_OF_DECLARE(vt8500_pll
, "via,vt8500-pll-clock", vt8500_pll_init
);
737 static void __init
wm8650_pll_init(struct device_node
*node
)
739 vtwm_pll_clk_init(node
, PLL_TYPE_WM8650
);
741 CLK_OF_DECLARE(wm8650_pll
, "wm,wm8650-pll-clock", wm8650_pll_init
);
743 static void __init
wm8750_pll_init(struct device_node
*node
)
745 vtwm_pll_clk_init(node
, PLL_TYPE_WM8750
);
747 CLK_OF_DECLARE(wm8750_pll
, "wm,wm8750-pll-clock", wm8750_pll_init
);
749 static void __init
wm8850_pll_init(struct device_node
*node
)
751 vtwm_pll_clk_init(node
, PLL_TYPE_WM8850
);
753 CLK_OF_DECLARE(wm8850_pll
, "wm,wm8850-pll-clock", wm8850_pll_init
);