xref: /linux/drivers/clk/actions/owl-divider.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // OWL divider clock driver
4 //
5 // Copyright (c) 2014 Actions Semi Inc.
6 // Author: David Liu <liuwei@actions-semi.com>
7 //
8 // Copyright (c) 2018 Linaro Ltd.
9 // Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
10 
11 #include <linux/clk-provider.h>
12 #include <linux/regmap.h>
13 
14 #include "owl-divider.h"
15 
16 static int owl_divider_determine_rate(struct clk_hw *hw,
17 				      struct clk_rate_request *req)
18 {
19 	struct owl_divider *div = hw_to_owl_divider(hw);
20 
21 	return divider_determine_rate(hw, req, div->div_hw.table,
22 				      div->div_hw.width, div->div_hw.div_flags);
23 }
24 
25 unsigned long owl_divider_helper_recalc_rate(struct owl_clk_common *common,
26 					 const struct owl_divider_hw *div_hw,
27 					 unsigned long parent_rate)
28 {
29 	unsigned long val;
30 	unsigned int reg;
31 
32 	regmap_read(common->regmap, div_hw->reg, &reg);
33 	val = reg >> div_hw->shift;
34 	val &= (1 << div_hw->width) - 1;
35 
36 	return divider_recalc_rate(&common->hw, parent_rate,
37 				   val, div_hw->table,
38 				   div_hw->div_flags,
39 				   div_hw->width);
40 }
41 
42 static unsigned long owl_divider_recalc_rate(struct clk_hw *hw,
43 					  unsigned long parent_rate)
44 {
45 	struct owl_divider *div = hw_to_owl_divider(hw);
46 
47 	return owl_divider_helper_recalc_rate(&div->common,
48 					      &div->div_hw, parent_rate);
49 }
50 
51 int owl_divider_helper_set_rate(const struct owl_clk_common *common,
52 				const struct owl_divider_hw *div_hw,
53 				unsigned long rate,
54 				unsigned long parent_rate)
55 {
56 	unsigned long val;
57 	unsigned int reg;
58 
59 	val = divider_get_val(rate, parent_rate, div_hw->table,
60 			      div_hw->width, 0);
61 
62 	regmap_read(common->regmap, div_hw->reg, &reg);
63 	reg &= ~GENMASK(div_hw->width + div_hw->shift - 1, div_hw->shift);
64 
65 	regmap_write(common->regmap, div_hw->reg,
66 			  reg | (val << div_hw->shift));
67 
68 	return 0;
69 }
70 
71 static int owl_divider_set_rate(struct clk_hw *hw, unsigned long rate,
72 				unsigned long parent_rate)
73 {
74 	struct owl_divider *div = hw_to_owl_divider(hw);
75 
76 	return owl_divider_helper_set_rate(&div->common, &div->div_hw,
77 					rate, parent_rate);
78 }
79 
80 const struct clk_ops owl_divider_ops = {
81 	.recalc_rate = owl_divider_recalc_rate,
82 	.determine_rate = owl_divider_determine_rate,
83 	.set_rate = owl_divider_set_rate,
84 };
85