1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 ROHM Semiconductors
3
4 #include <linux/kernel.h>
5 #include <linux/module.h>
6 #include <linux/init.h>
7 #include <linux/err.h>
8 #include <linux/platform_device.h>
9 #include <linux/slab.h>
10 #include <linux/mfd/rohm-bd718x7.h>
11 #include <linux/mfd/rohm-bd70528.h>
12 #include <linux/clk-provider.h>
13 #include <linux/clkdev.h>
14 #include <linux/regmap.h>
15
16 struct bd718xx_clk {
17 struct clk_hw hw;
18 u8 reg;
19 u8 mask;
20 struct platform_device *pdev;
21 struct rohm_regmap_dev *mfd;
22 };
23
bd71837_clk_set(struct clk_hw * hw,int status)24 static int bd71837_clk_set(struct clk_hw *hw, int status)
25 {
26 struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
27
28 return regmap_update_bits(c->mfd->regmap, c->reg, c->mask, status);
29 }
30
bd71837_clk_disable(struct clk_hw * hw)31 static void bd71837_clk_disable(struct clk_hw *hw)
32 {
33 int rv;
34 struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
35
36 rv = bd71837_clk_set(hw, 0);
37 if (rv)
38 dev_dbg(&c->pdev->dev, "Failed to disable 32K clk (%d)\n", rv);
39 }
40
bd71837_clk_enable(struct clk_hw * hw)41 static int bd71837_clk_enable(struct clk_hw *hw)
42 {
43 return bd71837_clk_set(hw, 1);
44 }
45
bd71837_clk_is_enabled(struct clk_hw * hw)46 static int bd71837_clk_is_enabled(struct clk_hw *hw)
47 {
48 int enabled;
49 int rval;
50 struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw);
51
52 rval = regmap_read(c->mfd->regmap, c->reg, &enabled);
53
54 if (rval)
55 return rval;
56
57 return enabled & c->mask;
58 }
59
60 static const struct clk_ops bd71837_clk_ops = {
61 .prepare = &bd71837_clk_enable,
62 .unprepare = &bd71837_clk_disable,
63 .is_prepared = &bd71837_clk_is_enabled,
64 };
65
bd71837_clk_probe(struct platform_device * pdev)66 static int bd71837_clk_probe(struct platform_device *pdev)
67 {
68 struct bd718xx_clk *c;
69 int rval = -ENOMEM;
70 const char *parent_clk;
71 struct device *parent = pdev->dev.parent;
72 struct rohm_regmap_dev *mfd = dev_get_drvdata(parent);
73 struct clk_init_data init = {
74 .name = "bd718xx-32k-out",
75 .ops = &bd71837_clk_ops,
76 };
77
78 c = devm_kzalloc(&pdev->dev, sizeof(*c), GFP_KERNEL);
79 if (!c)
80 return -ENOMEM;
81
82 init.num_parents = 1;
83 parent_clk = of_clk_get_parent_name(parent->of_node, 0);
84
85 init.parent_names = &parent_clk;
86 if (!parent_clk) {
87 dev_err(&pdev->dev, "No parent clk found\n");
88 return -EINVAL;
89 }
90 switch (mfd->chip_type) {
91 case ROHM_CHIP_TYPE_BD71837:
92 case ROHM_CHIP_TYPE_BD71847:
93 c->reg = BD718XX_REG_OUT32K;
94 c->mask = BD718XX_OUT32K_EN;
95 break;
96 case ROHM_CHIP_TYPE_BD70528:
97 c->reg = BD70528_REG_CLK_OUT;
98 c->mask = BD70528_CLK_OUT_EN_MASK;
99 break;
100 default:
101 dev_err(&pdev->dev, "Unknown clk chip\n");
102 return -EINVAL;
103 }
104 c->mfd = mfd;
105 c->pdev = pdev;
106 c->hw.init = &init;
107
108 of_property_read_string_index(parent->of_node,
109 "clock-output-names", 0, &init.name);
110
111 rval = devm_clk_hw_register(&pdev->dev, &c->hw);
112 if (rval) {
113 dev_err(&pdev->dev, "failed to register 32K clk");
114 return rval;
115 }
116 rval = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
117 &c->hw);
118 if (rval)
119 dev_err(&pdev->dev, "adding clk provider failed\n");
120
121 return rval;
122 }
123
124 static struct platform_driver bd71837_clk = {
125 .driver = {
126 .name = "bd718xx-clk",
127 },
128 .probe = bd71837_clk_probe,
129 };
130
131 module_platform_driver(bd71837_clk);
132
133 MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
134 MODULE_DESCRIPTION("BD71837/BD71847/BD70528 chip clk driver");
135 MODULE_LICENSE("GPL");
136