1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/clk-provider.h>
7*4882a593Smuzhiyun #include <linux/clkdev.h>
8*4882a593Smuzhiyun #include <linux/clk/at91_pmc.h>
9*4882a593Smuzhiyun #include <linux/of.h>
10*4882a593Smuzhiyun #include <linux/mfd/syscon.h>
11*4882a593Smuzhiyun #include <linux/regmap.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "pmc.h"
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define SYSTEM_MAX_ID 31
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #define SYSTEM_MAX_NAME_SZ 32
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #define to_clk_system(hw) container_of(hw, struct clk_system, hw)
20*4882a593Smuzhiyun struct clk_system {
21*4882a593Smuzhiyun struct clk_hw hw;
22*4882a593Smuzhiyun struct regmap *regmap;
23*4882a593Smuzhiyun u8 id;
24*4882a593Smuzhiyun };
25*4882a593Smuzhiyun
is_pck(int id)26*4882a593Smuzhiyun static inline int is_pck(int id)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun return (id >= 8) && (id <= 15);
29*4882a593Smuzhiyun }
30*4882a593Smuzhiyun
clk_system_ready(struct regmap * regmap,int id)31*4882a593Smuzhiyun static inline bool clk_system_ready(struct regmap *regmap, int id)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun unsigned int status;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun regmap_read(regmap, AT91_PMC_SR, &status);
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun return !!(status & (1 << id));
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
clk_system_prepare(struct clk_hw * hw)40*4882a593Smuzhiyun static int clk_system_prepare(struct clk_hw *hw)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun struct clk_system *sys = to_clk_system(hw);
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id);
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun if (!is_pck(sys->id))
47*4882a593Smuzhiyun return 0;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun while (!clk_system_ready(sys->regmap, sys->id))
50*4882a593Smuzhiyun cpu_relax();
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun return 0;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
clk_system_unprepare(struct clk_hw * hw)55*4882a593Smuzhiyun static void clk_system_unprepare(struct clk_hw *hw)
56*4882a593Smuzhiyun {
57*4882a593Smuzhiyun struct clk_system *sys = to_clk_system(hw);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
clk_system_is_prepared(struct clk_hw * hw)62*4882a593Smuzhiyun static int clk_system_is_prepared(struct clk_hw *hw)
63*4882a593Smuzhiyun {
64*4882a593Smuzhiyun struct clk_system *sys = to_clk_system(hw);
65*4882a593Smuzhiyun unsigned int status;
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun regmap_read(sys->regmap, AT91_PMC_SCSR, &status);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun if (!(status & (1 << sys->id)))
70*4882a593Smuzhiyun return 0;
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun if (!is_pck(sys->id))
73*4882a593Smuzhiyun return 1;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun regmap_read(sys->regmap, AT91_PMC_SR, &status);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun return !!(status & (1 << sys->id));
78*4882a593Smuzhiyun }
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun static const struct clk_ops system_ops = {
81*4882a593Smuzhiyun .prepare = clk_system_prepare,
82*4882a593Smuzhiyun .unprepare = clk_system_unprepare,
83*4882a593Smuzhiyun .is_prepared = clk_system_is_prepared,
84*4882a593Smuzhiyun };
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun struct clk_hw * __init
at91_clk_register_system(struct regmap * regmap,const char * name,const char * parent_name,u8 id)87*4882a593Smuzhiyun at91_clk_register_system(struct regmap *regmap, const char *name,
88*4882a593Smuzhiyun const char *parent_name, u8 id)
89*4882a593Smuzhiyun {
90*4882a593Smuzhiyun struct clk_system *sys;
91*4882a593Smuzhiyun struct clk_hw *hw;
92*4882a593Smuzhiyun struct clk_init_data init;
93*4882a593Smuzhiyun int ret;
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun if (!parent_name || id > SYSTEM_MAX_ID)
96*4882a593Smuzhiyun return ERR_PTR(-EINVAL);
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun sys = kzalloc(sizeof(*sys), GFP_KERNEL);
99*4882a593Smuzhiyun if (!sys)
100*4882a593Smuzhiyun return ERR_PTR(-ENOMEM);
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun init.name = name;
103*4882a593Smuzhiyun init.ops = &system_ops;
104*4882a593Smuzhiyun init.parent_names = &parent_name;
105*4882a593Smuzhiyun init.num_parents = 1;
106*4882a593Smuzhiyun init.flags = CLK_SET_RATE_PARENT;
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun sys->id = id;
109*4882a593Smuzhiyun sys->hw.init = &init;
110*4882a593Smuzhiyun sys->regmap = regmap;
111*4882a593Smuzhiyun
112*4882a593Smuzhiyun hw = &sys->hw;
113*4882a593Smuzhiyun ret = clk_hw_register(NULL, &sys->hw);
114*4882a593Smuzhiyun if (ret) {
115*4882a593Smuzhiyun kfree(sys);
116*4882a593Smuzhiyun hw = ERR_PTR(ret);
117*4882a593Smuzhiyun }
118*4882a593Smuzhiyun
119*4882a593Smuzhiyun return hw;
120*4882a593Smuzhiyun }
121