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);