Eric Lee / smarc-fsl-linux-kernel

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drivers/clk/clk-multiplier.c 3.84 KB

e1bd55e5a Stephen Boyd clk: Tag basic cl...	1	// SPDX-License-Identifier: GPL-2.0
f2e0a5327 Maxime Ripard clk: Add a basic ...	2 3	/* * Copyright (C) 2015 Maxime Ripard <maxime.ripard@free-electrons.com>
f2e0a5327 Maxime Ripard clk: Add a basic ...	4 5 6 7 8 9	*/ #include <linux/bitops.h> #include <linux/clk-provider.h> #include <linux/err.h> #include <linux/export.h>
62e59c4e6 Stephen Boyd clk: Remove io.h ...	10	#include <linux/io.h>
f2e0a5327 Maxime Ripard clk: Add a basic ...	11 12 13	#include <linux/kernel.h> #include <linux/of.h> #include <linux/slab.h>
9427b71a8 Jonas Gorski clk: multiplier: ...	14 15 16 17	static inline u32 clk_mult_readl(struct clk_multiplier *mult) { if (mult->flags & CLK_MULTIPLIER_BIG_ENDIAN) return ioread32be(mult->reg);
5834fd75e Jonas Gorski clk: core: replac...	18	return readl(mult->reg);
9427b71a8 Jonas Gorski clk: multiplier: ...	19 20 21 22 23 24 25	} static inline void clk_mult_writel(struct clk_multiplier *mult, u32 val) { if (mult->flags & CLK_MULTIPLIER_BIG_ENDIAN) iowrite32be(val, mult->reg); else
5834fd75e Jonas Gorski clk: core: replac...	26	writel(val, mult->reg);
9427b71a8 Jonas Gorski clk: multiplier: ...	27	}
f2e0a5327 Maxime Ripard clk: Add a basic ...	28 29 30 31 32 33 34 35 36 37 38 39 40 41 42	static unsigned long __get_mult(struct clk_multiplier mult, unsigned long rate, unsigned long parent_rate) { if (mult->flags & CLK_MULTIPLIER_ROUND_CLOSEST) return DIV_ROUND_CLOSEST(rate, parent_rate); return rate / parent_rate; } static unsigned long clk_multiplier_recalc_rate(struct clk_hw hw, unsigned long parent_rate) { struct clk_multiplier *mult = to_clk_multiplier(hw); unsigned long val;
9427b71a8 Jonas Gorski clk: multiplier: ...	43	val = clk_mult_readl(mult) >> mult->shift;
f2e0a5327 Maxime Ripard clk: Add a basic ...	44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64	val &= GENMASK(mult->width - 1, 0); if (!val && mult->flags & CLK_MULTIPLIER_ZERO_BYPASS) val = 1; return parent_rate * val; } static bool __is_best_rate(unsigned long rate, unsigned long new, unsigned long best, unsigned long flags) { if (flags & CLK_MULTIPLIER_ROUND_CLOSEST) return abs(rate - new) < abs(rate - best); return new >= rate && new < best; } static unsigned long __bestmult(struct clk_hw hw, unsigned long rate, unsigned long best_parent_rate, u8 width, unsigned long flags) {
25f77a3aa Maxime Ripard clk: multiplier: ...	65	struct clk_multiplier *mult = to_clk_multiplier(hw);
f2e0a5327 Maxime Ripard clk: Add a basic ...	66 67 68	unsigned long orig_parent_rate = *best_parent_rate; unsigned long parent_rate, current_rate, best_rate = ~0; unsigned int i, bestmult = 0;
25f77a3aa Maxime Ripard clk: multiplier: ...	69 70 71 72 73 74 75 76 77	unsigned int maxmult = (1 << width) - 1; if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) { bestmult = rate / orig_parent_rate; /* Make sure we don't end up with a 0 multiplier */ if ((bestmult == 0) && !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS)) bestmult = 1;
f2e0a5327 Maxime Ripard clk: Add a basic ...	78
25f77a3aa Maxime Ripard clk: multiplier: ...	79 80 81 82 83 84	/* Make sure we don't overflow the multiplier */ if (bestmult > maxmult) bestmult = maxmult; return bestmult; }
f2e0a5327 Maxime Ripard clk: Add a basic ...	85
25f77a3aa Maxime Ripard clk: multiplier: ...	86	for (i = 1; i < maxmult; i++) {
f2e0a5327 Maxime Ripard clk: Add a basic ...	87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132	if (rate == orig_parent_rate * i) { /* * This is the best case for us if we have a * perfect match without changing the parent * rate. / best_parent_rate = orig_parent_rate; return i; } parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), rate / i); current_rate = parent_rate * i; if (__is_best_rate(rate, current_rate, best_rate, flags)) { bestmult = i; best_rate = current_rate; best_parent_rate = parent_rate; } } return bestmult; } static long clk_multiplier_round_rate(struct clk_hw hw, unsigned long rate, unsigned long parent_rate) { struct clk_multiplier mult = to_clk_multiplier(hw); unsigned long factor = __bestmult(hw, rate, parent_rate, mult->width, mult->flags); return parent_rate factor; } static int clk_multiplier_set_rate(struct clk_hw hw, unsigned long rate, unsigned long parent_rate) { struct clk_multiplier mult = to_clk_multiplier(hw); unsigned long factor = __get_mult(mult, rate, parent_rate); unsigned long flags = 0; unsigned long val; if (mult->lock) spin_lock_irqsave(mult->lock, flags); else __acquire(mult->lock);
9427b71a8 Jonas Gorski clk: multiplier: ...	133	val = clk_mult_readl(mult);
f2e0a5327 Maxime Ripard clk: Add a basic ...	134 135	val &= ~GENMASK(mult->width + mult->shift - 1, mult->shift); val \|= factor << mult->shift;
9427b71a8 Jonas Gorski clk: multiplier: ...	136	clk_mult_writel(mult, val);
f2e0a5327 Maxime Ripard clk: Add a basic ...	137 138 139 140 141 142 143 144 145 146 147 148 149 150 151	if (mult->lock) spin_unlock_irqrestore(mult->lock, flags); else __release(mult->lock); return 0; } const struct clk_ops clk_multiplier_ops = { .recalc_rate = clk_multiplier_recalc_rate, .round_rate = clk_multiplier_round_rate, .set_rate = clk_multiplier_set_rate, }; EXPORT_SYMBOL_GPL(clk_multiplier_ops);