xref: /linux/drivers/clk/meson/clk-cpu-dyndiv.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
2 /*
3  * Copyright (c) 2019 BayLibre, SAS.
4  * Author: Neil Armstrong <narmstrong@baylibre.com>
5  */
6 
7 #include <linux/clk-provider.h>
8 #include <linux/module.h>
9 
10 #include "clk-regmap.h"
11 #include "clk-cpu-dyndiv.h"
12 
13 static inline struct meson_clk_cpu_dyndiv_data *
14 meson_clk_cpu_dyndiv_data(struct clk_regmap *clk)
15 {
16 	return (struct meson_clk_cpu_dyndiv_data *)clk->data;
17 }
18 
19 static unsigned long meson_clk_cpu_dyndiv_recalc_rate(struct clk_hw *hw,
20 						      unsigned long prate)
21 {
22 	struct clk_regmap *clk = to_clk_regmap(hw);
23 	struct meson_clk_cpu_dyndiv_data *data = meson_clk_cpu_dyndiv_data(clk);
24 
25 	return divider_recalc_rate(hw, prate,
26 				   meson_parm_read(clk->map, &data->div),
27 				   NULL, 0, data->div.width);
28 }
29 
30 static int meson_clk_cpu_dyndiv_determine_rate(struct clk_hw *hw,
31 					       struct clk_rate_request *req)
32 {
33 	struct clk_regmap *clk = to_clk_regmap(hw);
34 	struct meson_clk_cpu_dyndiv_data *data = meson_clk_cpu_dyndiv_data(clk);
35 
36 	return divider_determine_rate(hw, req, NULL, data->div.width, 0);
37 }
38 
39 static int meson_clk_cpu_dyndiv_set_rate(struct clk_hw *hw, unsigned long rate,
40 					  unsigned long parent_rate)
41 {
42 	struct clk_regmap *clk = to_clk_regmap(hw);
43 	struct meson_clk_cpu_dyndiv_data *data = meson_clk_cpu_dyndiv_data(clk);
44 	unsigned int val;
45 	int ret;
46 
47 	ret = divider_get_val(rate, parent_rate, NULL, data->div.width, 0);
48 	if (ret < 0)
49 		return ret;
50 
51 	val = (unsigned int)ret << data->div.shift;
52 
53 	/* Write the SYS_CPU_DYN_ENABLE bit before changing the divider */
54 	meson_parm_write(clk->map, &data->dyn, 1);
55 
56 	/* Update the divider while removing the SYS_CPU_DYN_ENABLE bit */
57 	return regmap_update_bits(clk->map, data->div.reg_off,
58 				  SETPMASK(data->div.width, data->div.shift) |
59 				  SETPMASK(data->dyn.width, data->dyn.shift),
60 				  val);
61 };
62 
63 const struct clk_ops meson_clk_cpu_dyndiv_ops = {
64 	.recalc_rate = meson_clk_cpu_dyndiv_recalc_rate,
65 	.determine_rate = meson_clk_cpu_dyndiv_determine_rate,
66 	.set_rate = meson_clk_cpu_dyndiv_set_rate,
67 };
68 EXPORT_SYMBOL_GPL(meson_clk_cpu_dyndiv_ops);
69 
70 MODULE_DESCRIPTION("Amlogic CPU Dynamic Clock divider");
71 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
72 MODULE_LICENSE("GPL");
73