1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Ingenic SoC CGU driver
5 * Copyright (c) 2013-2015 Imagination Technologies
9 #include <linux/bitops.h>
10 #include <linux/clk.h>
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/delay.h>
15 #include <linux/math64.h>
17 #include <linux/of_address.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
22 #define MHZ (1000 * 1000)
25 * ingenic_cgu_gate_get() - get the value of clock gate register bit
26 * @cgu: reference to the CGU whose registers should be read
27 * @info: info struct describing the gate bit
29 * Retrieves the state of the clock gate bit described by info. The
30 * caller must hold cgu->lock.
32 * Return: true if the gate bit is set, else false.
35 ingenic_cgu_gate_get(struct ingenic_cgu *cgu,
36 const struct ingenic_cgu_gate_info *info)
38 return !!(readl(cgu->base + info->reg) & BIT(info->bit))
39 ^ info->clear_to_gate;
43 * ingenic_cgu_gate_set() - set the value of clock gate register bit
44 * @cgu: reference to the CGU whose registers should be modified
45 * @info: info struct describing the gate bit
46 * @val: non-zero to gate a clock, otherwise zero
48 * Sets the given gate bit in order to gate or ungate a clock.
50 * The caller must hold cgu->lock.
53 ingenic_cgu_gate_set(struct ingenic_cgu *cgu,
54 const struct ingenic_cgu_gate_info *info, bool val)
56 u32 clkgr = readl(cgu->base + info->reg);
58 if (val ^ info->clear_to_gate)
59 clkgr |= BIT(info->bit);
61 clkgr &= ~BIT(info->bit);
63 writel(clkgr, cgu->base + info->reg);
71 ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
73 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
74 struct ingenic_cgu *cgu = ingenic_clk->cgu;
75 const struct ingenic_cgu_clk_info *clk_info;
76 const struct ingenic_cgu_pll_info *pll_info;
77 unsigned m, n, od_enc, od;
82 clk_info = &cgu->clock_info[ingenic_clk->idx];
83 BUG_ON(clk_info->type != CGU_CLK_PLL);
84 pll_info = &clk_info->pll;
86 spin_lock_irqsave(&cgu->lock, flags);
87 ctl = readl(cgu->base + pll_info->reg);
88 spin_unlock_irqrestore(&cgu->lock, flags);
90 m = (ctl >> pll_info->m_shift) & GENMASK(pll_info->m_bits - 1, 0);
91 m += pll_info->m_offset;
92 n = (ctl >> pll_info->n_shift) & GENMASK(pll_info->n_bits - 1, 0);
93 n += pll_info->n_offset;
94 od_enc = ctl >> pll_info->od_shift;
95 od_enc &= GENMASK(pll_info->od_bits - 1, 0);
96 bypass = !pll_info->no_bypass_bit &&
97 !!(ctl & BIT(pll_info->bypass_bit));
102 for (od = 0; od < pll_info->od_max; od++) {
103 if (pll_info->od_encoding[od] == od_enc)
106 BUG_ON(od == pll_info->od_max);
109 return div_u64((u64)parent_rate * m, n * od);
113 ingenic_pll_calc(const struct ingenic_cgu_clk_info *clk_info,
114 unsigned long rate, unsigned long parent_rate,
115 unsigned *pm, unsigned *pn, unsigned *pod)
117 const struct ingenic_cgu_pll_info *pll_info;
120 pll_info = &clk_info->pll;
124 * The frequency after the input divider must be between 10 and 50 MHz.
125 * The highest divider yields the best resolution.
127 n = parent_rate / (10 * MHZ);
128 n = min_t(unsigned, n, 1 << clk_info->pll.n_bits);
129 n = max_t(unsigned, n, pll_info->n_offset);
131 m = (rate / MHZ) * od * n / (parent_rate / MHZ);
132 m = min_t(unsigned, m, 1 << clk_info->pll.m_bits);
133 m = max_t(unsigned, m, pll_info->m_offset);
142 return div_u64((u64)parent_rate * m, n * od);
145 static inline const struct ingenic_cgu_clk_info *to_clk_info(
146 struct ingenic_clk *ingenic_clk)
148 struct ingenic_cgu *cgu = ingenic_clk->cgu;
149 const struct ingenic_cgu_clk_info *clk_info;
151 clk_info = &cgu->clock_info[ingenic_clk->idx];
152 BUG_ON(clk_info->type != CGU_CLK_PLL);
158 ingenic_pll_round_rate(struct clk_hw *hw, unsigned long req_rate,
159 unsigned long *prate)
161 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
162 const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
164 return ingenic_pll_calc(clk_info, req_rate, *prate, NULL, NULL, NULL);
168 ingenic_pll_set_rate(struct clk_hw *hw, unsigned long req_rate,
169 unsigned long parent_rate)
171 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
172 struct ingenic_cgu *cgu = ingenic_clk->cgu;
173 const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
174 const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
175 unsigned long rate, flags;
176 unsigned int m, n, od;
179 rate = ingenic_pll_calc(clk_info, req_rate, parent_rate,
181 if (rate != req_rate)
182 pr_info("ingenic-cgu: request '%s' rate %luHz, actual %luHz\n",
183 clk_info->name, req_rate, rate);
185 spin_lock_irqsave(&cgu->lock, flags);
186 ctl = readl(cgu->base + pll_info->reg);
188 ctl &= ~(GENMASK(pll_info->m_bits - 1, 0) << pll_info->m_shift);
189 ctl |= (m - pll_info->m_offset) << pll_info->m_shift;
191 ctl &= ~(GENMASK(pll_info->n_bits - 1, 0) << pll_info->n_shift);
192 ctl |= (n - pll_info->n_offset) << pll_info->n_shift;
194 ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
195 ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;
197 writel(ctl, cgu->base + pll_info->reg);
198 spin_unlock_irqrestore(&cgu->lock, flags);
203 static int ingenic_pll_enable(struct clk_hw *hw)
205 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
206 struct ingenic_cgu *cgu = ingenic_clk->cgu;
207 const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
208 const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
209 const unsigned int timeout = 100;
214 spin_lock_irqsave(&cgu->lock, flags);
215 ctl = readl(cgu->base + pll_info->reg);
217 ctl &= ~BIT(pll_info->bypass_bit);
218 ctl |= BIT(pll_info->enable_bit);
220 writel(ctl, cgu->base + pll_info->reg);
222 /* wait for the PLL to stabilise */
223 for (i = 0; i < timeout; i++) {
224 ctl = readl(cgu->base + pll_info->reg);
225 if (ctl & BIT(pll_info->stable_bit))
230 spin_unlock_irqrestore(&cgu->lock, flags);
238 static void ingenic_pll_disable(struct clk_hw *hw)
240 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
241 struct ingenic_cgu *cgu = ingenic_clk->cgu;
242 const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
243 const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
247 spin_lock_irqsave(&cgu->lock, flags);
248 ctl = readl(cgu->base + pll_info->reg);
250 ctl &= ~BIT(pll_info->enable_bit);
252 writel(ctl, cgu->base + pll_info->reg);
253 spin_unlock_irqrestore(&cgu->lock, flags);
256 static int ingenic_pll_is_enabled(struct clk_hw *hw)
258 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
259 struct ingenic_cgu *cgu = ingenic_clk->cgu;
260 const struct ingenic_cgu_clk_info *clk_info = to_clk_info(ingenic_clk);
261 const struct ingenic_cgu_pll_info *pll_info = &clk_info->pll;
265 spin_lock_irqsave(&cgu->lock, flags);
266 ctl = readl(cgu->base + pll_info->reg);
267 spin_unlock_irqrestore(&cgu->lock, flags);
269 return !!(ctl & BIT(pll_info->enable_bit));
272 static const struct clk_ops ingenic_pll_ops = {
273 .recalc_rate = ingenic_pll_recalc_rate,
274 .round_rate = ingenic_pll_round_rate,
275 .set_rate = ingenic_pll_set_rate,
277 .enable = ingenic_pll_enable,
278 .disable = ingenic_pll_disable,
279 .is_enabled = ingenic_pll_is_enabled,
283 * Operations for all non-PLL clocks
286 static u8 ingenic_clk_get_parent(struct clk_hw *hw)
288 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
289 struct ingenic_cgu *cgu = ingenic_clk->cgu;
290 const struct ingenic_cgu_clk_info *clk_info;
292 u8 i, hw_idx, idx = 0;
294 clk_info = &cgu->clock_info[ingenic_clk->idx];
296 if (clk_info->type & CGU_CLK_MUX) {
297 reg = readl(cgu->base + clk_info->mux.reg);
298 hw_idx = (reg >> clk_info->mux.shift) &
299 GENMASK(clk_info->mux.bits - 1, 0);
302 * Convert the hardware index to the parent index by skipping
303 * over any -1's in the parents array.
305 for (i = 0; i < hw_idx; i++) {
306 if (clk_info->parents[i] != -1)
314 static int ingenic_clk_set_parent(struct clk_hw *hw, u8 idx)
316 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
317 struct ingenic_cgu *cgu = ingenic_clk->cgu;
318 const struct ingenic_cgu_clk_info *clk_info;
320 u8 curr_idx, hw_idx, num_poss;
323 clk_info = &cgu->clock_info[ingenic_clk->idx];
325 if (clk_info->type & CGU_CLK_MUX) {
327 * Convert the parent index to the hardware index by adding
328 * 1 for any -1 in the parents array preceding the given
329 * index. That is, we want the index of idx'th entry in
330 * clk_info->parents which does not equal -1.
332 hw_idx = curr_idx = 0;
333 num_poss = 1 << clk_info->mux.bits;
334 for (; hw_idx < num_poss; hw_idx++) {
335 if (clk_info->parents[hw_idx] == -1)
342 /* idx should always be a valid parent */
343 BUG_ON(curr_idx != idx);
345 mask = GENMASK(clk_info->mux.bits - 1, 0);
346 mask <<= clk_info->mux.shift;
348 spin_lock_irqsave(&cgu->lock, flags);
350 /* write the register */
351 reg = readl(cgu->base + clk_info->mux.reg);
353 reg |= hw_idx << clk_info->mux.shift;
354 writel(reg, cgu->base + clk_info->mux.reg);
356 spin_unlock_irqrestore(&cgu->lock, flags);
360 return idx ? -EINVAL : 0;
364 ingenic_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
366 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
367 struct ingenic_cgu *cgu = ingenic_clk->cgu;
368 const struct ingenic_cgu_clk_info *clk_info;
369 unsigned long rate = parent_rate;
372 clk_info = &cgu->clock_info[ingenic_clk->idx];
374 if (clk_info->type & CGU_CLK_DIV) {
375 div_reg = readl(cgu->base + clk_info->div.reg);
376 div = (div_reg >> clk_info->div.shift) &
377 GENMASK(clk_info->div.bits - 1, 0);
379 if (clk_info->div.div_table)
380 div = clk_info->div.div_table[div];
382 div = (div + 1) * clk_info->div.div;
385 } else if (clk_info->type & CGU_CLK_FIXDIV) {
386 rate /= clk_info->fixdiv.div;
393 ingenic_clk_calc_hw_div(const struct ingenic_cgu_clk_info *clk_info,
398 for (i = 0; i < (1 << clk_info->div.bits)
399 && clk_info->div.div_table[i]; i++) {
400 if (clk_info->div.div_table[i] >= div)
408 ingenic_clk_calc_div(const struct ingenic_cgu_clk_info *clk_info,
409 unsigned long parent_rate, unsigned long req_rate)
411 unsigned int div, hw_div;
413 /* calculate the divide */
414 div = DIV_ROUND_UP(parent_rate, req_rate);
416 if (clk_info->div.div_table) {
417 hw_div = ingenic_clk_calc_hw_div(clk_info, div);
419 return clk_info->div.div_table[hw_div];
422 /* Impose hardware constraints */
423 div = min_t(unsigned, div, 1 << clk_info->div.bits);
424 div = max_t(unsigned, div, 1);
427 * If the divider value itself must be divided before being written to
428 * the divider register, we must ensure we don't have any bits set that
429 * would be lost as a result of doing so.
431 div /= clk_info->div.div;
432 div *= clk_info->div.div;
438 ingenic_clk_round_rate(struct clk_hw *hw, unsigned long req_rate,
439 unsigned long *parent_rate)
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;
444 unsigned int div = 1;
446 clk_info = &cgu->clock_info[ingenic_clk->idx];
448 if (clk_info->type & CGU_CLK_DIV)
449 div = ingenic_clk_calc_div(clk_info, *parent_rate, req_rate);
450 else if (clk_info->type & CGU_CLK_FIXDIV)
451 div = clk_info->fixdiv.div;
453 return DIV_ROUND_UP(*parent_rate, div);
457 ingenic_clk_set_rate(struct clk_hw *hw, unsigned long req_rate,
458 unsigned long parent_rate)
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;
463 const unsigned timeout = 100;
464 unsigned long rate, flags;
465 unsigned int hw_div, div, i;
469 clk_info = &cgu->clock_info[ingenic_clk->idx];
471 if (clk_info->type & CGU_CLK_DIV) {
472 div = ingenic_clk_calc_div(clk_info, parent_rate, req_rate);
473 rate = DIV_ROUND_UP(parent_rate, div);
475 if (rate != req_rate)
478 if (clk_info->div.div_table)
479 hw_div = ingenic_clk_calc_hw_div(clk_info, div);
481 hw_div = ((div / clk_info->div.div) - 1);
483 spin_lock_irqsave(&cgu->lock, flags);
484 reg = readl(cgu->base + clk_info->div.reg);
486 /* update the divide */
487 mask = GENMASK(clk_info->div.bits - 1, 0);
488 reg &= ~(mask << clk_info->div.shift);
489 reg |= hw_div << clk_info->div.shift;
491 /* clear the stop bit */
492 if (clk_info->div.stop_bit != -1)
493 reg &= ~BIT(clk_info->div.stop_bit);
495 /* set the change enable bit */
496 if (clk_info->div.ce_bit != -1)
497 reg |= BIT(clk_info->div.ce_bit);
499 /* update the hardware */
500 writel(reg, cgu->base + clk_info->div.reg);
502 /* wait for the change to take effect */
503 if (clk_info->div.busy_bit != -1) {
504 for (i = 0; i < timeout; i++) {
505 reg = readl(cgu->base + clk_info->div.reg);
506 if (!(reg & BIT(clk_info->div.busy_bit)))
514 spin_unlock_irqrestore(&cgu->lock, flags);
521 static int ingenic_clk_enable(struct clk_hw *hw)
523 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
524 struct ingenic_cgu *cgu = ingenic_clk->cgu;
525 const struct ingenic_cgu_clk_info *clk_info;
528 clk_info = &cgu->clock_info[ingenic_clk->idx];
530 if (clk_info->type & CGU_CLK_GATE) {
531 /* ungate the clock */
532 spin_lock_irqsave(&cgu->lock, flags);
533 ingenic_cgu_gate_set(cgu, &clk_info->gate, false);
534 spin_unlock_irqrestore(&cgu->lock, flags);
536 if (clk_info->gate.delay_us)
537 udelay(clk_info->gate.delay_us);
543 static void ingenic_clk_disable(struct clk_hw *hw)
545 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
546 struct ingenic_cgu *cgu = ingenic_clk->cgu;
547 const struct ingenic_cgu_clk_info *clk_info;
550 clk_info = &cgu->clock_info[ingenic_clk->idx];
552 if (clk_info->type & CGU_CLK_GATE) {
554 spin_lock_irqsave(&cgu->lock, flags);
555 ingenic_cgu_gate_set(cgu, &clk_info->gate, true);
556 spin_unlock_irqrestore(&cgu->lock, flags);
560 static int ingenic_clk_is_enabled(struct clk_hw *hw)
562 struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw);
563 struct ingenic_cgu *cgu = ingenic_clk->cgu;
564 const struct ingenic_cgu_clk_info *clk_info;
568 clk_info = &cgu->clock_info[ingenic_clk->idx];
570 if (clk_info->type & CGU_CLK_GATE) {
571 spin_lock_irqsave(&cgu->lock, flags);
572 enabled = !ingenic_cgu_gate_get(cgu, &clk_info->gate);
573 spin_unlock_irqrestore(&cgu->lock, flags);
579 static const struct clk_ops ingenic_clk_ops = {
580 .get_parent = ingenic_clk_get_parent,
581 .set_parent = ingenic_clk_set_parent,
583 .recalc_rate = ingenic_clk_recalc_rate,
584 .round_rate = ingenic_clk_round_rate,
585 .set_rate = ingenic_clk_set_rate,
587 .enable = ingenic_clk_enable,
588 .disable = ingenic_clk_disable,
589 .is_enabled = ingenic_clk_is_enabled,
596 static int ingenic_register_clock(struct ingenic_cgu *cgu, unsigned idx)
598 const struct ingenic_cgu_clk_info *clk_info = &cgu->clock_info[idx];
599 struct clk_init_data clk_init;
600 struct ingenic_clk *ingenic_clk = NULL;
601 struct clk *clk, *parent;
602 const char *parent_names[4];
603 unsigned caps, i, num_possible;
606 BUILD_BUG_ON(ARRAY_SIZE(clk_info->parents) > ARRAY_SIZE(parent_names));
608 if (clk_info->type == CGU_CLK_EXT) {
609 clk = of_clk_get_by_name(cgu->np, clk_info->name);
611 pr_err("%s: no external clock '%s' provided\n",
612 __func__, clk_info->name);
616 err = clk_register_clkdev(clk, clk_info->name, NULL);
621 cgu->clocks.clks[idx] = clk;
625 if (!clk_info->type) {
626 pr_err("%s: no clock type specified for '%s'\n", __func__,
631 ingenic_clk = kzalloc(sizeof(*ingenic_clk), GFP_KERNEL);
637 ingenic_clk->hw.init = &clk_init;
638 ingenic_clk->cgu = cgu;
639 ingenic_clk->idx = idx;
641 clk_init.name = clk_info->name;
643 clk_init.parent_names = parent_names;
645 caps = clk_info->type;
647 if (caps & (CGU_CLK_MUX | CGU_CLK_CUSTOM)) {
648 clk_init.num_parents = 0;
650 if (caps & CGU_CLK_MUX)
651 num_possible = 1 << clk_info->mux.bits;
653 num_possible = ARRAY_SIZE(clk_info->parents);
655 for (i = 0; i < num_possible; i++) {
656 if (clk_info->parents[i] == -1)
659 parent = cgu->clocks.clks[clk_info->parents[i]];
660 parent_names[clk_init.num_parents] =
661 __clk_get_name(parent);
662 clk_init.num_parents++;
665 BUG_ON(!clk_init.num_parents);
666 BUG_ON(clk_init.num_parents > ARRAY_SIZE(parent_names));
668 BUG_ON(clk_info->parents[0] == -1);
669 clk_init.num_parents = 1;
670 parent = cgu->clocks.clks[clk_info->parents[0]];
671 parent_names[0] = __clk_get_name(parent);
674 if (caps & CGU_CLK_CUSTOM) {
675 clk_init.ops = clk_info->custom.clk_ops;
677 caps &= ~CGU_CLK_CUSTOM;
680 pr_err("%s: custom clock may not be combined with type 0x%x\n",
684 } else if (caps & CGU_CLK_PLL) {
685 clk_init.ops = &ingenic_pll_ops;
686 clk_init.flags |= CLK_SET_RATE_GATE;
688 caps &= ~CGU_CLK_PLL;
691 pr_err("%s: PLL may not be combined with type 0x%x\n",
696 clk_init.ops = &ingenic_clk_ops;
699 /* nothing to do for gates or fixed dividers */
700 caps &= ~(CGU_CLK_GATE | CGU_CLK_FIXDIV);
702 if (caps & CGU_CLK_MUX) {
703 if (!(caps & CGU_CLK_MUX_GLITCHFREE))
704 clk_init.flags |= CLK_SET_PARENT_GATE;
706 caps &= ~(CGU_CLK_MUX | CGU_CLK_MUX_GLITCHFREE);
709 if (caps & CGU_CLK_DIV) {
710 caps &= ~CGU_CLK_DIV;
712 /* pass rate changes to the parent clock */
713 clk_init.flags |= CLK_SET_RATE_PARENT;
717 pr_err("%s: unknown clock type 0x%x\n", __func__, caps);
721 clk = clk_register(NULL, &ingenic_clk->hw);
723 pr_err("%s: failed to register clock '%s'\n", __func__,
729 err = clk_register_clkdev(clk, clk_info->name, NULL);
733 cgu->clocks.clks[idx] = clk;
741 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
742 unsigned num_clocks, struct device_node *np)
744 struct ingenic_cgu *cgu;
746 cgu = kzalloc(sizeof(*cgu), GFP_KERNEL);
750 cgu->base = of_iomap(np, 0);
752 pr_err("%s: failed to map CGU registers\n", __func__);
757 cgu->clock_info = clock_info;
758 cgu->clocks.clk_num = num_clocks;
760 spin_lock_init(&cgu->lock);
770 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu)
775 cgu->clocks.clks = kcalloc(cgu->clocks.clk_num, sizeof(struct clk *),
777 if (!cgu->clocks.clks) {
782 for (i = 0; i < cgu->clocks.clk_num; i++) {
783 err = ingenic_register_clock(cgu, i);
785 goto err_out_unregister;
788 err = of_clk_add_provider(cgu->np, of_clk_src_onecell_get,
791 goto err_out_unregister;
796 for (i = 0; i < cgu->clocks.clk_num; i++) {
797 if (!cgu->clocks.clks[i])
799 if (cgu->clock_info[i].type & CGU_CLK_EXT)
800 clk_put(cgu->clocks.clks[i]);
802 clk_unregister(cgu->clocks.clks[i]);
804 kfree(cgu->clocks.clks);