1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * drivers/clk/at91/clk-slow.c
4  *
5  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/clkdev.h>
10 #include <linux/clk/at91_pmc.h>
11 #include <linux/of.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/regmap.h>
14 
15 #include "pmc.h"
16 
17 struct clk_sam9260_slow {
18 	struct clk_hw hw;
19 	struct regmap *regmap;
20 };
21 
22 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
23 
clk_sam9260_slow_get_parent(struct clk_hw * hw)24 static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
25 {
26 	struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
27 	unsigned int status;
28 
29 	regmap_read(slowck->regmap, AT91_PMC_SR, &status);
30 
31 	return status & AT91_PMC_OSCSEL ? 1 : 0;
32 }
33 
34 static const struct clk_ops sam9260_slow_ops = {
35 	.get_parent = clk_sam9260_slow_get_parent,
36 };
37 
38 struct clk_hw * __init
at91_clk_register_sam9260_slow(struct regmap * regmap,const char * name,const char ** parent_names,int num_parents)39 at91_clk_register_sam9260_slow(struct regmap *regmap,
40 			       const char *name,
41 			       const char **parent_names,
42 			       int num_parents)
43 {
44 	struct clk_sam9260_slow *slowck;
45 	struct clk_hw *hw;
46 	struct clk_init_data init;
47 	int ret;
48 
49 	if (!name)
50 		return ERR_PTR(-EINVAL);
51 
52 	if (!parent_names || !num_parents)
53 		return ERR_PTR(-EINVAL);
54 
55 	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
56 	if (!slowck)
57 		return ERR_PTR(-ENOMEM);
58 
59 	init.name = name;
60 	init.ops = &sam9260_slow_ops;
61 	init.parent_names = parent_names;
62 	init.num_parents = num_parents;
63 	init.flags = 0;
64 
65 	slowck->hw.init = &init;
66 	slowck->regmap = regmap;
67 
68 	hw = &slowck->hw;
69 	ret = clk_hw_register(NULL, &slowck->hw);
70 	if (ret) {
71 		kfree(slowck);
72 		hw = ERR_PTR(ret);
73 	}
74 
75 	return hw;
76 }
77