xref: /openbmc/linux/drivers/clk/imx/clk-gpr-mux.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  */
4 
5 #define pr_fmt(fmt) "imx:clk-gpr-mux: " fmt
6 
7 #include <linux/module.h>
8 
9 #include <linux/clk-provider.h>
10 #include <linux/errno.h>
11 #include <linux/export.h>
12 #include <linux/io.h>
13 #include <linux/slab.h>
14 #include <linux/regmap.h>
15 #include <linux/mfd/syscon.h>
16 
17 #include "clk.h"
18 
19 struct imx_clk_gpr {
20 	struct clk_hw hw;
21 	struct regmap *regmap;
22 	u32 mask;
23 	u32 reg;
24 	const u32 *mux_table;
25 };
26 
27 static struct imx_clk_gpr *to_imx_clk_gpr(struct clk_hw *hw)
28 {
29 	return container_of(hw, struct imx_clk_gpr, hw);
30 }
31 
32 static u8 imx_clk_gpr_mux_get_parent(struct clk_hw *hw)
33 {
34 	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
35 	unsigned int val;
36 	int ret;
37 
38 	ret = regmap_read(priv->regmap, priv->reg, &val);
39 	if (ret)
40 		goto get_parent_err;
41 
42 	val &= priv->mask;
43 
44 	ret = clk_mux_val_to_index(hw, priv->mux_table, 0, val);
45 	if (ret < 0)
46 		goto get_parent_err;
47 
48 	return ret;
49 
50 get_parent_err:
51 	pr_err("failed to get parent (%pe)\n", ERR_PTR(ret));
52 
53 	/* return some realistic non negative value. Potentially we could
54 	 * give index to some dummy error parent.
55 	 */
56 	return 0;
57 }
58 
59 static int imx_clk_gpr_mux_set_parent(struct clk_hw *hw, u8 index)
60 {
61 	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
62 	unsigned int val = clk_mux_index_to_val(priv->mux_table, 0, index);
63 
64 	return regmap_update_bits(priv->regmap, priv->reg, priv->mask, val);
65 }
66 
67 static int imx_clk_gpr_mux_determine_rate(struct clk_hw *hw,
68 					 struct clk_rate_request *req)
69 {
70 	return clk_mux_determine_rate_flags(hw, req, 0);
71 }
72 
73 static const struct clk_ops imx_clk_gpr_mux_ops = {
74 	.get_parent = imx_clk_gpr_mux_get_parent,
75 	.set_parent = imx_clk_gpr_mux_set_parent,
76 	.determine_rate = imx_clk_gpr_mux_determine_rate,
77 };
78 
79 struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
80 			       u32 reg, const char **parent_names,
81 			       u8 num_parents, const u32 *mux_table, u32 mask)
82 {
83 	struct clk_init_data init  = { };
84 	struct imx_clk_gpr *priv;
85 	struct regmap *regmap;
86 	struct clk_hw *hw;
87 	int ret;
88 
89 	regmap = syscon_regmap_lookup_by_compatible(compatible);
90 	if (IS_ERR(regmap)) {
91 		pr_err("failed to find %s regmap\n", compatible);
92 		return ERR_CAST(regmap);
93 	}
94 
95 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
96 	if (!priv)
97 		return ERR_PTR(-ENOMEM);
98 
99 	init.name = name;
100 	init.ops = &imx_clk_gpr_mux_ops;
101 	init.parent_names = parent_names;
102 	init.num_parents = num_parents;
103 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
104 
105 	priv->hw.init = &init;
106 	priv->regmap = regmap;
107 	priv->mux_table = mux_table;
108 	priv->reg = reg;
109 	priv->mask = mask;
110 
111 	hw = &priv->hw;
112 	ret = clk_hw_register(NULL, &priv->hw);
113 	if (ret) {
114 		kfree(priv);
115 		hw = ERR_PTR(ret);
116 	}
117 
118 	return hw;
119 }
120