1 // SPDX-License-Identifier: GPL-2.0-only
3 * Clock implementation for VIA/Wondermedia SoC's
4 * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
9 #include <linux/of_address.h>
10 #include <linux/slab.h>
11 #include <linux/bitops.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk-provider.h>
15 #define LEGACY_PMC_BASE 0xD8130000
17 /* All clocks share the same lock as none can be changed concurrently */
18 static DEFINE_SPINLOCK(_lock
);
22 void __iomem
*div_reg
;
23 unsigned int div_mask
;
30 * Add new PLL_TYPE_x definitions here as required. Use the first known model
31 * to support the new type as the name.
32 * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
33 * vtwm_pll_set_rate() to handle the new PLL_TYPE_x
36 #define PLL_TYPE_VT8500 0
37 #define PLL_TYPE_WM8650 1
38 #define PLL_TYPE_WM8750 2
39 #define PLL_TYPE_WM8850 3
48 static void __iomem
*pmc_base
;
50 static __init
void vtwm_set_pmc_base(void)
52 struct device_node
*np
=
53 of_find_compatible_node(NULL
, NULL
, "via,vt8500-pmc");
56 pmc_base
= of_iomap(np
, 0);
58 pmc_base
= ioremap(LEGACY_PMC_BASE
, 0x1000);
62 pr_err("%s:of_iomap(pmc) failed\n", __func__
);
65 #define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)
67 #define VT8500_PMC_BUSY_MASK 0x18
69 static void vt8500_pmc_wait_busy(void)
71 while (readl(pmc_base
) & VT8500_PMC_BUSY_MASK
)
75 static int vt8500_dclk_enable(struct clk_hw
*hw
)
77 struct clk_device
*cdev
= to_clk_device(hw
);
79 unsigned long flags
= 0;
81 spin_lock_irqsave(cdev
->lock
, flags
);
83 en_val
= readl(cdev
->en_reg
);
84 en_val
|= BIT(cdev
->en_bit
);
85 writel(en_val
, cdev
->en_reg
);
87 spin_unlock_irqrestore(cdev
->lock
, flags
);
91 static void vt8500_dclk_disable(struct clk_hw
*hw
)
93 struct clk_device
*cdev
= to_clk_device(hw
);
95 unsigned long flags
= 0;
97 spin_lock_irqsave(cdev
->lock
, flags
);
99 en_val
= readl(cdev
->en_reg
);
100 en_val
&= ~BIT(cdev
->en_bit
);
101 writel(en_val
, cdev
->en_reg
);
103 spin_unlock_irqrestore(cdev
->lock
, flags
);
106 static int vt8500_dclk_is_enabled(struct clk_hw
*hw
)
108 struct clk_device
*cdev
= to_clk_device(hw
);
109 u32 en_val
= (readl(cdev
->en_reg
) & BIT(cdev
->en_bit
));
111 return en_val
? 1 : 0;
114 static unsigned long vt8500_dclk_recalc_rate(struct clk_hw
*hw
,
115 unsigned long parent_rate
)
117 struct clk_device
*cdev
= to_clk_device(hw
);
118 u32 div
= readl(cdev
->div_reg
) & cdev
->div_mask
;
120 /* Special case for SDMMC devices */
121 if ((cdev
->div_mask
== 0x3F) && (div
& BIT(5)))
122 div
= 64 * (div
& 0x1f);
124 /* div == 0 is actually the highest divisor */
126 div
= (cdev
->div_mask
+ 1);
128 return parent_rate
/ div
;
131 static long vt8500_dclk_round_rate(struct clk_hw
*hw
, unsigned long rate
,
132 unsigned long *prate
)
134 struct clk_device
*cdev
= to_clk_device(hw
);
140 divisor
= *prate
/ rate
;
142 /* If prate / rate would be decimal, incr the divisor */
143 if (rate
* divisor
< *prate
)
147 * If this is a request for SDMMC we have to adjust the divisor
148 * when >31 to use the fixed predivisor
150 if ((cdev
->div_mask
== 0x3F) && (divisor
> 31)) {
151 divisor
= 64 * ((divisor
/ 64) + 1);
154 return *prate
/ divisor
;
157 static int vt8500_dclk_set_rate(struct clk_hw
*hw
, unsigned long rate
,
158 unsigned long parent_rate
)
160 struct clk_device
*cdev
= to_clk_device(hw
);
162 unsigned long flags
= 0;
167 divisor
= parent_rate
/ rate
;
169 if (divisor
== cdev
->div_mask
+ 1)
172 /* SDMMC mask may need to be corrected before testing if its valid */
173 if ((cdev
->div_mask
== 0x3F) && (divisor
> 31)) {
175 * Bit 5 is a fixed /64 predivisor. If the requested divisor
176 * is >31 then correct for the fixed divisor being required.
178 divisor
= 0x20 + (divisor
/ 64);
181 if (divisor
> cdev
->div_mask
) {
182 pr_err("%s: invalid divisor for clock\n", __func__
);
186 spin_lock_irqsave(cdev
->lock
, flags
);
188 vt8500_pmc_wait_busy();
189 writel(divisor
, cdev
->div_reg
);
190 vt8500_pmc_wait_busy();
192 spin_unlock_irqrestore(cdev
->lock
, flags
);
198 static const struct clk_ops vt8500_gated_clk_ops
= {
199 .enable
= vt8500_dclk_enable
,
200 .disable
= vt8500_dclk_disable
,
201 .is_enabled
= vt8500_dclk_is_enabled
,
204 static const struct clk_ops vt8500_divisor_clk_ops
= {
205 .round_rate
= vt8500_dclk_round_rate
,
206 .set_rate
= vt8500_dclk_set_rate
,
207 .recalc_rate
= vt8500_dclk_recalc_rate
,
210 static const struct clk_ops vt8500_gated_divisor_clk_ops
= {
211 .enable
= vt8500_dclk_enable
,
212 .disable
= vt8500_dclk_disable
,
213 .is_enabled
= vt8500_dclk_is_enabled
,
214 .round_rate
= vt8500_dclk_round_rate
,
215 .set_rate
= vt8500_dclk_set_rate
,
216 .recalc_rate
= vt8500_dclk_recalc_rate
,
219 #define CLK_INIT_GATED BIT(0)
220 #define CLK_INIT_DIVISOR BIT(1)
221 #define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED)
223 static __init
void vtwm_device_clk_init(struct device_node
*node
)
227 struct clk_device
*dev_clk
;
228 const char *clk_name
= node
->name
;
229 const char *parent_name
;
230 struct clk_init_data init
;
232 int clk_init_flags
= 0;
237 dev_clk
= kzalloc(sizeof(*dev_clk
), GFP_KERNEL
);
238 if (WARN_ON(!dev_clk
))
241 dev_clk
->lock
= &_lock
;
243 rc
= of_property_read_u32(node
, "enable-reg", &en_reg
);
245 dev_clk
->en_reg
= pmc_base
+ en_reg
;
246 rc
= of_property_read_u32(node
, "enable-bit", &dev_clk
->en_bit
);
248 pr_err("%s: enable-bit property required for gated clock\n",
252 clk_init_flags
|= CLK_INIT_GATED
;
255 rc
= of_property_read_u32(node
, "divisor-reg", &div_reg
);
257 dev_clk
->div_reg
= pmc_base
+ div_reg
;
259 * use 0x1f as the default mask since it covers
260 * almost all the clocks and reduces dts properties
262 dev_clk
->div_mask
= 0x1f;
264 of_property_read_u32(node
, "divisor-mask", &dev_clk
->div_mask
);
265 clk_init_flags
|= CLK_INIT_DIVISOR
;
268 of_property_read_string(node
, "clock-output-names", &clk_name
);
270 switch (clk_init_flags
) {
272 init
.ops
= &vt8500_gated_clk_ops
;
274 case CLK_INIT_DIVISOR
:
275 init
.ops
= &vt8500_divisor_clk_ops
;
277 case CLK_INIT_GATED_DIVISOR
:
278 init
.ops
= &vt8500_gated_divisor_clk_ops
;
281 pr_err("%s: Invalid clock description in device tree\n",
287 init
.name
= clk_name
;
289 parent_name
= of_clk_get_parent_name(node
, 0);
290 init
.parent_names
= &parent_name
;
291 init
.num_parents
= 1;
293 dev_clk
->hw
.init
= &init
;
296 rc
= clk_hw_register(NULL
, hw
);
301 rc
= of_clk_add_hw_provider(node
, of_clk_hw_simple_get
, hw
);
302 clk_hw_register_clkdev(hw
, clk_name
, NULL
);
304 CLK_OF_DECLARE(vt8500_device
, "via,vt8500-device-clock", vtwm_device_clk_init
);
306 /* PLL clock related functions */
308 #define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
310 /* Helper macros for PLL_VT8500 */
311 #define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
312 #define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)
314 #define VT8500_BITS_TO_FREQ(r, m, d) \
317 #define VT8500_BITS_TO_VAL(m, d) \
318 ((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))
320 /* Helper macros for PLL_WM8650 */
321 #define WM8650_PLL_MUL(x) (x & 0x3FF)
322 #define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))
324 #define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
325 (r * m / (d1 * (1 << d2)))
327 #define WM8650_BITS_TO_VAL(m, d1, d2) \
328 ((d2 << 13) | (d1 << 10) | (m & 0x3FF))
330 /* Helper macros for PLL_WM8750 */
331 #define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1)
332 #define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7)))
334 #define WM8750_BITS_TO_FREQ(r, m, d1, d2) \
335 (r * (m+1) / ((d1+1) * (1 << d2)))
337 #define WM8750_BITS_TO_VAL(f, m, d1, d2) \
338 ((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2)
340 /* Helper macros for PLL_WM8850 */
341 #define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2)
342 #define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3)))
344 #define WM8850_BITS_TO_FREQ(r, m, d1, d2) \
345 (r * ((m + 1) * 2) / ((d1+1) * (1 << d2)))
347 #define WM8850_BITS_TO_VAL(m, d1, d2) \
348 ((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2)
350 static int vt8500_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
351 u32
*multiplier
, u32
*prediv
)
356 if ((rate
< parent_rate
* 4) || (rate
> parent_rate
* 62)) {
357 pr_err("%s: requested rate out of range\n", __func__
);
362 if (rate
<= parent_rate
* 31)
363 /* use the prediv to double the resolution */
368 *multiplier
= rate
/ (parent_rate
/ *prediv
);
369 tclk
= (parent_rate
/ *prediv
) * *multiplier
;
372 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
,
379 * M * parent [O1] => / P [O2] => / D [O3]
380 * Where O1 is 900MHz...3GHz;
381 * O2 is 600MHz >= (M * parent) / P >= 300MHz;
382 * M is 36...120 [25MHz parent]; D is 1 or 2 or 4 or 8.
383 * Possible ranges (O3):
384 * D = 8: 37,5MHz...75MHz
385 * D = 4: 75MHz...150MHz
386 * D = 2: 150MHz...300MHz
387 * D = 1: 300MHz...600MHz
389 static int wm8650_find_pll_bits(unsigned long rate
,
390 unsigned long parent_rate
, u32
*multiplier
, u32
*divisor1
,
393 unsigned long O1
, min_err
, rate_err
;
395 if (!parent_rate
|| (rate
< 37500000) || (rate
> 600000000))
398 *divisor2
= rate
<= 75000000 ? 3 : rate
<= 150000000 ? 2 :
399 rate
<= 300000000 ? 1 : 0;
401 * Divisor P cannot be calculated. Test all divisors and find where M
402 * will be as close as possible to the requested rate.
405 for (*divisor1
= 5; *divisor1
>= 3; (*divisor1
)--) {
406 O1
= rate
* *divisor1
* (1 << (*divisor2
));
407 rate_err
= O1
% parent_rate
;
408 if (rate_err
< min_err
) {
409 *multiplier
= O1
/ parent_rate
;
417 if ((*multiplier
< 3) || (*multiplier
> 1023))
420 pr_warn("%s: rate error is %lu\n", __func__
, min_err
);
425 static u32
wm8750_get_filter(u32 parent_rate
, u32 divisor1
)
427 /* calculate frequency (MHz) after pre-divisor */
428 u32 freq
= (parent_rate
/ 1000000) / (divisor1
+ 1);
430 if ((freq
< 10) || (freq
> 200))
431 pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n",
436 else if (freq
>= 104)
452 static int wm8750_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
453 u32
*filter
, u32
*multiplier
, u32
*divisor1
, u32
*divisor2
)
457 unsigned long tclk
, rate_err
, best_err
;
459 best_err
= (unsigned long)-1;
461 /* Find the closest match (lower or equal to requested) */
462 for (div1
= 1; div1
>= 0; div1
--)
463 for (div2
= 7; div2
>= 0; div2
--)
464 for (mul
= 0; mul
<= 255; mul
++) {
465 tclk
= parent_rate
* (mul
+ 1) / ((div1
+ 1) * (1 << div2
));
468 /* error will always be +ve */
469 rate_err
= rate
- tclk
;
471 *filter
= wm8750_get_filter(parent_rate
, div1
);
478 if (rate_err
< best_err
) {
486 if (best_err
== (unsigned long)-1) {
487 pr_warn("%s: impossible rate %lu\n", __func__
, rate
);
491 /* if we got here, it wasn't an exact match */
492 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
, rate
,
495 *filter
= wm8750_get_filter(parent_rate
, *divisor1
);
500 static int wm8850_find_pll_bits(unsigned long rate
, unsigned long parent_rate
,
501 u32
*multiplier
, u32
*divisor1
, u32
*divisor2
)
505 unsigned long tclk
, rate_err
, best_err
;
507 best_err
= (unsigned long)-1;
509 /* Find the closest match (lower or equal to requested) */
510 for (div1
= 1; div1
>= 0; div1
--)
511 for (div2
= 3; div2
>= 0; div2
--)
512 for (mul
= 0; mul
<= 127; mul
++) {
513 tclk
= parent_rate
* ((mul
+ 1) * 2) /
514 ((div1
+ 1) * (1 << div2
));
517 /* error will always be +ve */
518 rate_err
= rate
- tclk
;
526 if (rate_err
< best_err
) {
534 if (best_err
== (unsigned long)-1) {
535 pr_warn("%s: impossible rate %lu\n", __func__
, rate
);
539 /* if we got here, it wasn't an exact match */
540 pr_warn("%s: requested rate %lu, found rate %lu\n", __func__
, rate
,
546 static int vtwm_pll_set_rate(struct clk_hw
*hw
, unsigned long rate
,
547 unsigned long parent_rate
)
549 struct clk_pll
*pll
= to_clk_pll(hw
);
550 u32 filter
, mul
, div1
, div2
;
552 unsigned long flags
= 0;
558 case PLL_TYPE_VT8500
:
559 ret
= vt8500_find_pll_bits(rate
, parent_rate
, &mul
, &div1
);
561 pll_val
= VT8500_BITS_TO_VAL(mul
, div1
);
563 case PLL_TYPE_WM8650
:
564 ret
= wm8650_find_pll_bits(rate
, parent_rate
, &mul
, &div1
, &div2
);
566 pll_val
= WM8650_BITS_TO_VAL(mul
, div1
, div2
);
568 case PLL_TYPE_WM8750
:
569 ret
= wm8750_find_pll_bits(rate
, parent_rate
, &filter
, &mul
, &div1
, &div2
);
571 pll_val
= WM8750_BITS_TO_VAL(filter
, mul
, div1
, div2
);
573 case PLL_TYPE_WM8850
:
574 ret
= wm8850_find_pll_bits(rate
, parent_rate
, &mul
, &div1
, &div2
);
576 pll_val
= WM8850_BITS_TO_VAL(mul
, div1
, div2
);
579 pr_err("%s: invalid pll type\n", __func__
);
586 spin_lock_irqsave(pll
->lock
, flags
);
588 vt8500_pmc_wait_busy();
589 writel(pll_val
, pll
->reg
);
590 vt8500_pmc_wait_busy();
592 spin_unlock_irqrestore(pll
->lock
, flags
);
597 static long vtwm_pll_round_rate(struct clk_hw
*hw
, unsigned long rate
,
598 unsigned long *prate
)
600 struct clk_pll
*pll
= to_clk_pll(hw
);
601 u32 filter
, mul
, div1
, div2
;
606 case PLL_TYPE_VT8500
:
607 ret
= vt8500_find_pll_bits(rate
, *prate
, &mul
, &div1
);
609 round_rate
= VT8500_BITS_TO_FREQ(*prate
, mul
, div1
);
611 case PLL_TYPE_WM8650
:
612 ret
= wm8650_find_pll_bits(rate
, *prate
, &mul
, &div1
, &div2
);
614 round_rate
= WM8650_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
616 case PLL_TYPE_WM8750
:
617 ret
= wm8750_find_pll_bits(rate
, *prate
, &filter
, &mul
, &div1
, &div2
);
619 round_rate
= WM8750_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
621 case PLL_TYPE_WM8850
:
622 ret
= wm8850_find_pll_bits(rate
, *prate
, &mul
, &div1
, &div2
);
624 round_rate
= WM8850_BITS_TO_FREQ(*prate
, mul
, div1
, div2
);
636 static unsigned long vtwm_pll_recalc_rate(struct clk_hw
*hw
,
637 unsigned long parent_rate
)
639 struct clk_pll
*pll
= to_clk_pll(hw
);
640 u32 pll_val
= readl(pll
->reg
);
641 unsigned long pll_freq
;
644 case PLL_TYPE_VT8500
:
645 pll_freq
= parent_rate
* VT8500_PLL_MUL(pll_val
);
646 pll_freq
/= VT8500_PLL_DIV(pll_val
);
648 case PLL_TYPE_WM8650
:
649 pll_freq
= parent_rate
* WM8650_PLL_MUL(pll_val
);
650 pll_freq
/= WM8650_PLL_DIV(pll_val
);
652 case PLL_TYPE_WM8750
:
653 pll_freq
= parent_rate
* WM8750_PLL_MUL(pll_val
);
654 pll_freq
/= WM8750_PLL_DIV(pll_val
);
656 case PLL_TYPE_WM8850
:
657 pll_freq
= parent_rate
* WM8850_PLL_MUL(pll_val
);
658 pll_freq
/= WM8850_PLL_DIV(pll_val
);
667 static const struct clk_ops vtwm_pll_ops
= {
668 .round_rate
= vtwm_pll_round_rate
,
669 .set_rate
= vtwm_pll_set_rate
,
670 .recalc_rate
= vtwm_pll_recalc_rate
,
673 static __init
void vtwm_pll_clk_init(struct device_node
*node
, int pll_type
)
677 struct clk_pll
*pll_clk
;
678 const char *clk_name
= node
->name
;
679 const char *parent_name
;
680 struct clk_init_data init
;
686 rc
= of_property_read_u32(node
, "reg", ®
);
690 pll_clk
= kzalloc(sizeof(*pll_clk
), GFP_KERNEL
);
691 if (WARN_ON(!pll_clk
))
694 pll_clk
->reg
= pmc_base
+ reg
;
695 pll_clk
->lock
= &_lock
;
696 pll_clk
->type
= pll_type
;
698 of_property_read_string(node
, "clock-output-names", &clk_name
);
700 init
.name
= clk_name
;
701 init
.ops
= &vtwm_pll_ops
;
703 parent_name
= of_clk_get_parent_name(node
, 0);
704 init
.parent_names
= &parent_name
;
705 init
.num_parents
= 1;
707 pll_clk
->hw
.init
= &init
;
710 rc
= clk_hw_register(NULL
, &pll_clk
->hw
);
715 rc
= of_clk_add_hw_provider(node
, of_clk_hw_simple_get
, hw
);
716 clk_hw_register_clkdev(hw
, clk_name
, NULL
);
720 /* Wrappers for initialization functions */
722 static void __init
vt8500_pll_init(struct device_node
*node
)
724 vtwm_pll_clk_init(node
, PLL_TYPE_VT8500
);
726 CLK_OF_DECLARE(vt8500_pll
, "via,vt8500-pll-clock", vt8500_pll_init
);
728 static void __init
wm8650_pll_init(struct device_node
*node
)
730 vtwm_pll_clk_init(node
, PLL_TYPE_WM8650
);
732 CLK_OF_DECLARE(wm8650_pll
, "wm,wm8650-pll-clock", wm8650_pll_init
);
734 static void __init
wm8750_pll_init(struct device_node
*node
)
736 vtwm_pll_clk_init(node
, PLL_TYPE_WM8750
);
738 CLK_OF_DECLARE(wm8750_pll
, "wm,wm8750-pll-clock", wm8750_pll_init
);
740 static void __init
wm8850_pll_init(struct device_node
*node
)
742 vtwm_pll_clk_init(node
, PLL_TYPE_WM8850
);
744 CLK_OF_DECLARE(wm8850_pll
, "wm,wm8850-pll-clock", wm8850_pll_init
);