1 // SPDX-License-Identifier: GPL-2.0-only
9 #define pr_fmt(fmt) "clk-frac-synth: " fmt
11 #include <linux/clk-provider.h>
15 #include "clk.h"
24  * Fout= Fin/2*div (division factor)
25  * div is 17 bits:-
26  *	0-13 (fractional part)
27  *	14-16 (integer part)
28  *	div is (16-14 bits).(13-0 bits) (in binary)
30  *	Fout = Fin/(2 * div)
31  *	Fout = ((Fin / 10000)/(2 * div)) * 10000
32  *	Fout = (2^14 * (Fin / 10000)/(2^14 * (2 * div))) * 10000
33  *	Fout = (((Fin / 10000) << 14)/(2 * (div << 14))) * 10000
35  * div << 14 simply 17 bit value written at register.
45 	struct frac_rate_tbl *rtbl = frac->rtbl;  in frac_calc_rate()
49 	prate /= (2 * rtbl[index].div);  in frac_calc_rate()
62 			frac->rtbl_cnt, &unused);  in clk_frac_round_rate()
70 	unsigned int div = 1, val;  in clk_frac_recalc_rate()  local
72 	if (frac->lock)  in clk_frac_recalc_rate()
73 		spin_lock_irqsave(frac->lock, flags);  in clk_frac_recalc_rate()
75 	val = readl_relaxed(frac->reg);  in clk_frac_recalc_rate()
77 	if (frac->lock)  in clk_frac_recalc_rate()
78 		spin_unlock_irqrestore(frac->lock, flags);  in clk_frac_recalc_rate()
80 	div = val & DIV_FACTOR_MASK;  in clk_frac_recalc_rate()
82 	if (!div)  in clk_frac_recalc_rate()
87 	parent_rate = (parent_rate << 14) / (2 * div);  in clk_frac_recalc_rate()
96 	struct frac_rate_tbl *rtbl = frac->rtbl;  in clk_frac_set_rate()
100 	clk_round_rate_index(hw, drate, prate, frac_calc_rate, frac->rtbl_cnt,  in clk_frac_set_rate()
103 	if (frac->lock)  in clk_frac_set_rate()
104 		spin_lock_irqsave(frac->lock, flags);  in clk_frac_set_rate()
106 	val = readl_relaxed(frac->reg) & ~DIV_FACTOR_MASK;  in clk_frac_set_rate()
107 	val |= rtbl[i].div & DIV_FACTOR_MASK;  in clk_frac_set_rate()
108 	writel_relaxed(val, frac->reg);  in clk_frac_set_rate()
110 	if (frac->lock)  in clk_frac_set_rate()
111 		spin_unlock_irqrestore(frac->lock, flags);  in clk_frac_set_rate()
122 struct clk *clk_register_frac(const char *name, const char *parent_name,  in clk_register_frac()
128 	struct clk *clk;  in clk_register_frac()  local
132 		return ERR_PTR(-EINVAL);  in clk_register_frac()
137 		return ERR_PTR(-ENOMEM);  in clk_register_frac()
140 	frac->reg = reg;  in clk_register_frac()
141 	frac->rtbl = rtbl;  in clk_register_frac()
142 	frac->rtbl_cnt = rtbl_cnt;  in clk_register_frac()
143 	frac->lock = lock;  in clk_register_frac()
144 	frac->hw.init = &init;  in clk_register_frac()
152 	clk = clk_register(NULL, &frac->hw);  in clk_register_frac()
153 	if (!IS_ERR_OR_NULL(clk))  in clk_register_frac()
154 		return clk;  in clk_register_frac()
156 	pr_err("clk register failed\n");  in clk_register_frac()