2 * Ingenic SoC CGU driver
4 * Copyright (c) 2013-2015 Imagination Technologies
5 * Author: Paul Burton <paul.burton@imgtec.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/bitops.h>
19 #include <linux/clk.h>
20 #include <linux/clk-provider.h>
21 #include <linux/clkdev.h>
22 #include <linux/delay.h>
23 #include <linux/math64.h>
25 #include <linux/of_address.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
30 #define MHZ (1000 * 1000)
33 * ingenic_cgu_gate_get() - get the value of clock gate register bit
34 * @cgu: reference to the CGU whose registers should be read
35 * @info: info struct describing the gate bit
37 * Retrieves the state of the clock gate bit described by info. The
38 * caller must hold cgu->lock.
40 * Return: true if the gate bit is set, else false.
43 ingenic_cgu_gate_get(struct ingenic_cgu
*cgu
,
44 const struct ingenic_cgu_gate_info
*info
)
46 return readl(cgu
->base
+ info
->reg
) & BIT(info
->bit
);
50 * ingenic_cgu_gate_set() - set the value of clock gate register bit
51 * @cgu: reference to the CGU whose registers should be modified
52 * @info: info struct describing the gate bit
53 * @val: non-zero to gate a clock, otherwise zero
55 * Sets the given gate bit in order to gate or ungate a clock.
57 * The caller must hold cgu->lock.
60 ingenic_cgu_gate_set(struct ingenic_cgu
*cgu
,
61 const struct ingenic_cgu_gate_info
*info
, bool val
)
63 u32 clkgr
= readl(cgu
->base
+ info
->reg
);
66 clkgr
|= BIT(info
->bit
);
68 clkgr
&= ~BIT(info
->bit
);
70 writel(clkgr
, cgu
->base
+ info
->reg
);
78 ingenic_pll_recalc_rate(struct clk_hw
*hw
, unsigned long parent_rate
)
80 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
81 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
82 const struct ingenic_cgu_clk_info
*clk_info
;
83 const struct ingenic_cgu_pll_info
*pll_info
;
84 unsigned m
, n
, od_enc
, od
;
89 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
90 BUG_ON(clk_info
->type
!= CGU_CLK_PLL
);
91 pll_info
= &clk_info
->pll
;
93 spin_lock_irqsave(&cgu
->lock
, flags
);
94 ctl
= readl(cgu
->base
+ pll_info
->reg
);
95 spin_unlock_irqrestore(&cgu
->lock
, flags
);
97 m
= (ctl
>> pll_info
->m_shift
) & GENMASK(pll_info
->m_bits
- 1, 0);
98 m
+= pll_info
->m_offset
;
99 n
= (ctl
>> pll_info
->n_shift
) & GENMASK(pll_info
->n_bits
- 1, 0);
100 n
+= pll_info
->n_offset
;
101 od_enc
= ctl
>> pll_info
->od_shift
;
102 od_enc
&= GENMASK(pll_info
->od_bits
- 1, 0);
103 bypass
= !!(ctl
& BIT(pll_info
->bypass_bit
));
104 enable
= !!(ctl
& BIT(pll_info
->enable_bit
));
112 for (od
= 0; od
< pll_info
->od_max
; od
++) {
113 if (pll_info
->od_encoding
[od
] == od_enc
)
116 BUG_ON(od
== pll_info
->od_max
);
119 return div_u64((u64
)parent_rate
* m
, n
* od
);
123 ingenic_pll_calc(const struct ingenic_cgu_clk_info
*clk_info
,
124 unsigned long rate
, unsigned long parent_rate
,
125 unsigned *pm
, unsigned *pn
, unsigned *pod
)
127 const struct ingenic_cgu_pll_info
*pll_info
;
130 pll_info
= &clk_info
->pll
;
134 * The frequency after the input divider must be between 10 and 50 MHz.
135 * The highest divider yields the best resolution.
137 n
= parent_rate
/ (10 * MHZ
);
138 n
= min_t(unsigned, n
, 1 << clk_info
->pll
.n_bits
);
139 n
= max_t(unsigned, n
, pll_info
->n_offset
);
141 m
= (rate
/ MHZ
) * od
* n
/ (parent_rate
/ MHZ
);
142 m
= min_t(unsigned, m
, 1 << clk_info
->pll
.m_bits
);
143 m
= max_t(unsigned, m
, pll_info
->m_offset
);
152 return div_u64((u64
)parent_rate
* m
, n
* od
);
156 ingenic_pll_round_rate(struct clk_hw
*hw
, unsigned long req_rate
,
157 unsigned long *prate
)
159 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
160 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
161 const struct ingenic_cgu_clk_info
*clk_info
;
163 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
164 BUG_ON(clk_info
->type
!= CGU_CLK_PLL
);
166 return ingenic_pll_calc(clk_info
, req_rate
, *prate
, NULL
, NULL
, NULL
);
170 ingenic_pll_set_rate(struct clk_hw
*hw
, unsigned long req_rate
,
171 unsigned long parent_rate
)
173 const unsigned timeout
= 100;
174 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
175 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
176 const struct ingenic_cgu_clk_info
*clk_info
;
177 const struct ingenic_cgu_pll_info
*pll_info
;
178 unsigned long rate
, flags
;
179 unsigned m
, n
, od
, i
;
182 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
183 BUG_ON(clk_info
->type
!= CGU_CLK_PLL
);
184 pll_info
= &clk_info
->pll
;
186 rate
= ingenic_pll_calc(clk_info
, req_rate
, parent_rate
,
188 if (rate
!= req_rate
)
189 pr_info("ingenic-cgu: request '%s' rate %luHz, actual %luHz\n",
190 clk_info
->name
, req_rate
, rate
);
192 spin_lock_irqsave(&cgu
->lock
, flags
);
193 ctl
= readl(cgu
->base
+ pll_info
->reg
);
195 ctl
&= ~(GENMASK(pll_info
->m_bits
- 1, 0) << pll_info
->m_shift
);
196 ctl
|= (m
- pll_info
->m_offset
) << pll_info
->m_shift
;
198 ctl
&= ~(GENMASK(pll_info
->n_bits
- 1, 0) << pll_info
->n_shift
);
199 ctl
|= (n
- pll_info
->n_offset
) << pll_info
->n_shift
;
201 ctl
&= ~(GENMASK(pll_info
->od_bits
- 1, 0) << pll_info
->od_shift
);
202 ctl
|= pll_info
->od_encoding
[od
- 1] << pll_info
->od_shift
;
204 ctl
&= ~BIT(pll_info
->bypass_bit
);
205 ctl
|= BIT(pll_info
->enable_bit
);
207 writel(ctl
, cgu
->base
+ pll_info
->reg
);
209 /* wait for the PLL to stabilise */
210 for (i
= 0; i
< timeout
; i
++) {
211 ctl
= readl(cgu
->base
+ pll_info
->reg
);
212 if (ctl
& BIT(pll_info
->stable_bit
))
217 spin_unlock_irqrestore(&cgu
->lock
, flags
);
225 static const struct clk_ops ingenic_pll_ops
= {
226 .recalc_rate
= ingenic_pll_recalc_rate
,
227 .round_rate
= ingenic_pll_round_rate
,
228 .set_rate
= ingenic_pll_set_rate
,
232 * Operations for all non-PLL clocks
235 static u8
ingenic_clk_get_parent(struct clk_hw
*hw
)
237 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
238 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
239 const struct ingenic_cgu_clk_info
*clk_info
;
241 u8 i
, hw_idx
, idx
= 0;
243 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
245 if (clk_info
->type
& CGU_CLK_MUX
) {
246 reg
= readl(cgu
->base
+ clk_info
->mux
.reg
);
247 hw_idx
= (reg
>> clk_info
->mux
.shift
) &
248 GENMASK(clk_info
->mux
.bits
- 1, 0);
251 * Convert the hardware index to the parent index by skipping
252 * over any -1's in the parents array.
254 for (i
= 0; i
< hw_idx
; i
++) {
255 if (clk_info
->parents
[i
] != -1)
263 static int ingenic_clk_set_parent(struct clk_hw
*hw
, u8 idx
)
265 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
266 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
267 const struct ingenic_cgu_clk_info
*clk_info
;
269 u8 curr_idx
, hw_idx
, num_poss
;
272 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
274 if (clk_info
->type
& CGU_CLK_MUX
) {
276 * Convert the parent index to the hardware index by adding
277 * 1 for any -1 in the parents array preceding the given
278 * index. That is, we want the index of idx'th entry in
279 * clk_info->parents which does not equal -1.
281 hw_idx
= curr_idx
= 0;
282 num_poss
= 1 << clk_info
->mux
.bits
;
283 for (; hw_idx
< num_poss
; hw_idx
++) {
284 if (clk_info
->parents
[hw_idx
] == -1)
291 /* idx should always be a valid parent */
292 BUG_ON(curr_idx
!= idx
);
294 mask
= GENMASK(clk_info
->mux
.bits
- 1, 0);
295 mask
<<= clk_info
->mux
.shift
;
297 spin_lock_irqsave(&cgu
->lock
, flags
);
299 /* write the register */
300 reg
= readl(cgu
->base
+ clk_info
->mux
.reg
);
302 reg
|= hw_idx
<< clk_info
->mux
.shift
;
303 writel(reg
, cgu
->base
+ clk_info
->mux
.reg
);
305 spin_unlock_irqrestore(&cgu
->lock
, flags
);
309 return idx
? -EINVAL
: 0;
313 ingenic_clk_recalc_rate(struct clk_hw
*hw
, unsigned long parent_rate
)
315 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
316 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
317 const struct ingenic_cgu_clk_info
*clk_info
;
318 unsigned long rate
= parent_rate
;
321 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
323 if (clk_info
->type
& CGU_CLK_DIV
) {
324 div_reg
= readl(cgu
->base
+ clk_info
->div
.reg
);
325 div
= (div_reg
>> clk_info
->div
.shift
) &
326 GENMASK(clk_info
->div
.bits
- 1, 0);
328 div
*= clk_info
->div
.div
;
337 ingenic_clk_calc_div(const struct ingenic_cgu_clk_info
*clk_info
,
338 unsigned long parent_rate
, unsigned long req_rate
)
342 /* calculate the divide */
343 div
= DIV_ROUND_UP(parent_rate
, req_rate
);
345 /* and impose hardware constraints */
346 div
= min_t(unsigned, div
, 1 << clk_info
->div
.bits
);
347 div
= max_t(unsigned, div
, 1);
350 * If the divider value itself must be divided before being written to
351 * the divider register, we must ensure we don't have any bits set that
352 * would be lost as a result of doing so.
354 div
/= clk_info
->div
.div
;
355 div
*= clk_info
->div
.div
;
361 ingenic_clk_round_rate(struct clk_hw
*hw
, unsigned long req_rate
,
362 unsigned long *parent_rate
)
364 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
365 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
366 const struct ingenic_cgu_clk_info
*clk_info
;
367 long rate
= *parent_rate
;
369 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
371 if (clk_info
->type
& CGU_CLK_DIV
)
372 rate
/= ingenic_clk_calc_div(clk_info
, *parent_rate
, req_rate
);
373 else if (clk_info
->type
& CGU_CLK_FIXDIV
)
374 rate
/= clk_info
->fixdiv
.div
;
380 ingenic_clk_set_rate(struct clk_hw
*hw
, unsigned long req_rate
,
381 unsigned long parent_rate
)
383 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
384 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
385 const struct ingenic_cgu_clk_info
*clk_info
;
386 const unsigned timeout
= 100;
387 unsigned long rate
, flags
;
392 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
394 if (clk_info
->type
& CGU_CLK_DIV
) {
395 div
= ingenic_clk_calc_div(clk_info
, parent_rate
, req_rate
);
396 rate
= parent_rate
/ div
;
398 if (rate
!= req_rate
)
401 spin_lock_irqsave(&cgu
->lock
, flags
);
402 reg
= readl(cgu
->base
+ clk_info
->div
.reg
);
404 /* update the divide */
405 mask
= GENMASK(clk_info
->div
.bits
- 1, 0);
406 reg
&= ~(mask
<< clk_info
->div
.shift
);
407 reg
|= ((div
/ clk_info
->div
.div
) - 1) << clk_info
->div
.shift
;
409 /* clear the stop bit */
410 if (clk_info
->div
.stop_bit
!= -1)
411 reg
&= ~BIT(clk_info
->div
.stop_bit
);
413 /* set the change enable bit */
414 if (clk_info
->div
.ce_bit
!= -1)
415 reg
|= BIT(clk_info
->div
.ce_bit
);
417 /* update the hardware */
418 writel(reg
, cgu
->base
+ clk_info
->div
.reg
);
420 /* wait for the change to take effect */
421 if (clk_info
->div
.busy_bit
!= -1) {
422 for (i
= 0; i
< timeout
; i
++) {
423 reg
= readl(cgu
->base
+ clk_info
->div
.reg
);
424 if (!(reg
& BIT(clk_info
->div
.busy_bit
)))
432 spin_unlock_irqrestore(&cgu
->lock
, flags
);
439 static int ingenic_clk_enable(struct clk_hw
*hw
)
441 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
442 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
443 const struct ingenic_cgu_clk_info
*clk_info
;
446 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
448 if (clk_info
->type
& CGU_CLK_GATE
) {
449 /* ungate the clock */
450 spin_lock_irqsave(&cgu
->lock
, flags
);
451 ingenic_cgu_gate_set(cgu
, &clk_info
->gate
, false);
452 spin_unlock_irqrestore(&cgu
->lock
, flags
);
458 static void ingenic_clk_disable(struct clk_hw
*hw
)
460 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
461 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
462 const struct ingenic_cgu_clk_info
*clk_info
;
465 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
467 if (clk_info
->type
& CGU_CLK_GATE
) {
469 spin_lock_irqsave(&cgu
->lock
, flags
);
470 ingenic_cgu_gate_set(cgu
, &clk_info
->gate
, true);
471 spin_unlock_irqrestore(&cgu
->lock
, flags
);
475 static int ingenic_clk_is_enabled(struct clk_hw
*hw
)
477 struct ingenic_clk
*ingenic_clk
= to_ingenic_clk(hw
);
478 struct ingenic_cgu
*cgu
= ingenic_clk
->cgu
;
479 const struct ingenic_cgu_clk_info
*clk_info
;
483 clk_info
= &cgu
->clock_info
[ingenic_clk
->idx
];
485 if (clk_info
->type
& CGU_CLK_GATE
) {
486 spin_lock_irqsave(&cgu
->lock
, flags
);
487 enabled
= !ingenic_cgu_gate_get(cgu
, &clk_info
->gate
);
488 spin_unlock_irqrestore(&cgu
->lock
, flags
);
494 static const struct clk_ops ingenic_clk_ops
= {
495 .get_parent
= ingenic_clk_get_parent
,
496 .set_parent
= ingenic_clk_set_parent
,
498 .recalc_rate
= ingenic_clk_recalc_rate
,
499 .round_rate
= ingenic_clk_round_rate
,
500 .set_rate
= ingenic_clk_set_rate
,
502 .enable
= ingenic_clk_enable
,
503 .disable
= ingenic_clk_disable
,
504 .is_enabled
= ingenic_clk_is_enabled
,
511 static int ingenic_register_clock(struct ingenic_cgu
*cgu
, unsigned idx
)
513 const struct ingenic_cgu_clk_info
*clk_info
= &cgu
->clock_info
[idx
];
514 struct clk_init_data clk_init
;
515 struct ingenic_clk
*ingenic_clk
= NULL
;
516 struct clk
*clk
, *parent
;
517 const char *parent_names
[4];
518 unsigned caps
, i
, num_possible
;
521 BUILD_BUG_ON(ARRAY_SIZE(clk_info
->parents
) > ARRAY_SIZE(parent_names
));
523 if (clk_info
->type
== CGU_CLK_EXT
) {
524 clk
= of_clk_get_by_name(cgu
->np
, clk_info
->name
);
526 pr_err("%s: no external clock '%s' provided\n",
527 __func__
, clk_info
->name
);
531 err
= clk_register_clkdev(clk
, clk_info
->name
, NULL
);
536 cgu
->clocks
.clks
[idx
] = clk
;
540 if (!clk_info
->type
) {
541 pr_err("%s: no clock type specified for '%s'\n", __func__
,
546 ingenic_clk
= kzalloc(sizeof(*ingenic_clk
), GFP_KERNEL
);
552 ingenic_clk
->hw
.init
= &clk_init
;
553 ingenic_clk
->cgu
= cgu
;
554 ingenic_clk
->idx
= idx
;
556 clk_init
.name
= clk_info
->name
;
558 clk_init
.parent_names
= parent_names
;
560 caps
= clk_info
->type
;
562 if (caps
& (CGU_CLK_MUX
| CGU_CLK_CUSTOM
)) {
563 clk_init
.num_parents
= 0;
565 if (caps
& CGU_CLK_MUX
)
566 num_possible
= 1 << clk_info
->mux
.bits
;
568 num_possible
= ARRAY_SIZE(clk_info
->parents
);
570 for (i
= 0; i
< num_possible
; i
++) {
571 if (clk_info
->parents
[i
] == -1)
574 parent
= cgu
->clocks
.clks
[clk_info
->parents
[i
]];
575 parent_names
[clk_init
.num_parents
] =
576 __clk_get_name(parent
);
577 clk_init
.num_parents
++;
580 BUG_ON(!clk_init
.num_parents
);
581 BUG_ON(clk_init
.num_parents
> ARRAY_SIZE(parent_names
));
583 BUG_ON(clk_info
->parents
[0] == -1);
584 clk_init
.num_parents
= 1;
585 parent
= cgu
->clocks
.clks
[clk_info
->parents
[0]];
586 parent_names
[0] = __clk_get_name(parent
);
589 if (caps
& CGU_CLK_CUSTOM
) {
590 clk_init
.ops
= clk_info
->custom
.clk_ops
;
592 caps
&= ~CGU_CLK_CUSTOM
;
595 pr_err("%s: custom clock may not be combined with type 0x%x\n",
599 } else if (caps
& CGU_CLK_PLL
) {
600 clk_init
.ops
= &ingenic_pll_ops
;
602 caps
&= ~CGU_CLK_PLL
;
605 pr_err("%s: PLL may not be combined with type 0x%x\n",
610 clk_init
.ops
= &ingenic_clk_ops
;
613 /* nothing to do for gates or fixed dividers */
614 caps
&= ~(CGU_CLK_GATE
| CGU_CLK_FIXDIV
);
616 if (caps
& CGU_CLK_MUX
) {
617 if (!(caps
& CGU_CLK_MUX_GLITCHFREE
))
618 clk_init
.flags
|= CLK_SET_PARENT_GATE
;
620 caps
&= ~(CGU_CLK_MUX
| CGU_CLK_MUX_GLITCHFREE
);
623 if (caps
& CGU_CLK_DIV
) {
624 caps
&= ~CGU_CLK_DIV
;
626 /* pass rate changes to the parent clock */
627 clk_init
.flags
|= CLK_SET_RATE_PARENT
;
631 pr_err("%s: unknown clock type 0x%x\n", __func__
, caps
);
635 clk
= clk_register(NULL
, &ingenic_clk
->hw
);
637 pr_err("%s: failed to register clock '%s'\n", __func__
,
643 err
= clk_register_clkdev(clk
, clk_info
->name
, NULL
);
647 cgu
->clocks
.clks
[idx
] = clk
;
655 ingenic_cgu_new(const struct ingenic_cgu_clk_info
*clock_info
,
656 unsigned num_clocks
, struct device_node
*np
)
658 struct ingenic_cgu
*cgu
;
660 cgu
= kzalloc(sizeof(*cgu
), GFP_KERNEL
);
664 cgu
->base
= of_iomap(np
, 0);
666 pr_err("%s: failed to map CGU registers\n", __func__
);
671 cgu
->clock_info
= clock_info
;
672 cgu
->clocks
.clk_num
= num_clocks
;
674 spin_lock_init(&cgu
->lock
);
684 int ingenic_cgu_register_clocks(struct ingenic_cgu
*cgu
)
689 cgu
->clocks
.clks
= kcalloc(cgu
->clocks
.clk_num
, sizeof(struct clk
*),
691 if (!cgu
->clocks
.clks
) {
696 for (i
= 0; i
< cgu
->clocks
.clk_num
; i
++) {
697 err
= ingenic_register_clock(cgu
, i
);
699 goto err_out_unregister
;
702 err
= of_clk_add_provider(cgu
->np
, of_clk_src_onecell_get
,
705 goto err_out_unregister
;
710 for (i
= 0; i
< cgu
->clocks
.clk_num
; i
++) {
711 if (!cgu
->clocks
.clks
[i
])
713 if (cgu
->clock_info
[i
].type
& CGU_CLK_EXT
)
714 clk_put(cgu
->clocks
.clks
[i
]);
716 clk_unregister(cgu
->clocks
.clks
[i
]);
718 kfree(cgu
->clocks
.clks
);