1 /*
2  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/bitops.h>
16 #include <linux/regmap.h>
17 #include <linux/export.h>
18 
19 #include "clk-regmap-divider.h"
20 
21 static inline struct clk_regmap_div *to_clk_regmap_div(struct clk_hw *hw)
22 {
23 	return container_of(to_clk_regmap(hw), struct clk_regmap_div, clkr);
24 }
25 
26 static long div_round_ro_rate(struct clk_hw *hw, unsigned long rate,
27 			      unsigned long *prate)
28 {
29 	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
30 	struct clk_regmap *clkr = &divider->clkr;
31 	u32 div;
32 	struct clk_hw *hw_parent = clk_hw_get_parent(hw);
33 
34 	regmap_read(clkr->regmap, divider->reg, &div);
35 	div >>= divider->shift;
36 	div &= BIT(divider->width) - 1;
37 	div += 1;
38 
39 	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
40 		if (!hw_parent)
41 			return -EINVAL;
42 
43 		*prate = clk_hw_round_rate(hw_parent, rate * div);
44 	}
45 
46 	return DIV_ROUND_UP_ULL((u64)*prate, div);
47 }
48 
49 static long div_round_rate(struct clk_hw *hw, unsigned long rate,
50 			   unsigned long *prate)
51 {
52 	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
53 
54 	return divider_round_rate(hw, rate, prate, NULL, divider->width,
55 				  CLK_DIVIDER_ROUND_CLOSEST);
56 }
57 
58 static int div_set_rate(struct clk_hw *hw, unsigned long rate,
59 			unsigned long parent_rate)
60 {
61 	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
62 	struct clk_regmap *clkr = &divider->clkr;
63 	u32 div;
64 
65 	div = divider_get_val(rate, parent_rate, NULL, divider->width,
66 			      CLK_DIVIDER_ROUND_CLOSEST);
67 
68 	return regmap_update_bits(clkr->regmap, divider->reg,
69 				  (BIT(divider->width) - 1) << divider->shift,
70 				  div << divider->shift);
71 }
72 
73 static unsigned long div_recalc_rate(struct clk_hw *hw,
74 				     unsigned long parent_rate)
75 {
76 	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
77 	struct clk_regmap *clkr = &divider->clkr;
78 	u32 div;
79 
80 	regmap_read(clkr->regmap, divider->reg, &div);
81 	div >>= divider->shift;
82 	div &= BIT(divider->width) - 1;
83 
84 	return divider_recalc_rate(hw, parent_rate, div, NULL,
85 				   CLK_DIVIDER_ROUND_CLOSEST);
86 }
87 
88 const struct clk_ops clk_regmap_div_ops = {
89 	.round_rate = div_round_rate,
90 	.set_rate = div_set_rate,
91 	.recalc_rate = div_recalc_rate,
92 };
93 EXPORT_SYMBOL_GPL(clk_regmap_div_ops);
94 
95 const struct clk_ops clk_regmap_div_ro_ops = {
96 	.round_rate = div_round_ro_rate,
97 	.recalc_rate = div_recalc_rate,
98 };
99 EXPORT_SYMBOL_GPL(clk_regmap_div_ro_ops);
100