xref: /openbmc/linux/drivers/clk/clk-rk808.c (revision 9b5db89e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Clkout driver for Rockchip RK808
4  *
5  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
6  *
7  * Author:Chris Zhong <zyw@rock-chips.com>
8  */
9 
10 #include <linux/clk-provider.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/platform_device.h>
14 #include <linux/mfd/rk808.h>
15 #include <linux/i2c.h>
16 
17 struct rk808_clkout {
18 	struct rk808 *rk808;
19 	struct clk_hw		clkout1_hw;
20 	struct clk_hw		clkout2_hw;
21 };
22 
23 static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
24 					      unsigned long parent_rate)
25 {
26 	return 32768;
27 }
28 
29 static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
30 {
31 	struct rk808_clkout *rk808_clkout = container_of(hw,
32 							 struct rk808_clkout,
33 							 clkout2_hw);
34 	struct rk808 *rk808 = rk808_clkout->rk808;
35 
36 	return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
37 				  CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
38 }
39 
40 static int rk808_clkout2_prepare(struct clk_hw *hw)
41 {
42 	return rk808_clkout2_enable(hw, true);
43 }
44 
45 static void rk808_clkout2_unprepare(struct clk_hw *hw)
46 {
47 	rk808_clkout2_enable(hw, false);
48 }
49 
50 static int rk808_clkout2_is_prepared(struct clk_hw *hw)
51 {
52 	struct rk808_clkout *rk808_clkout = container_of(hw,
53 							 struct rk808_clkout,
54 							 clkout2_hw);
55 	struct rk808 *rk808 = rk808_clkout->rk808;
56 	uint32_t val;
57 
58 	int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
59 
60 	if (ret < 0)
61 		return ret;
62 
63 	return (val & CLK32KOUT2_EN) ? 1 : 0;
64 }
65 
66 static const struct clk_ops rk808_clkout1_ops = {
67 	.recalc_rate = rk808_clkout_recalc_rate,
68 };
69 
70 static const struct clk_ops rk808_clkout2_ops = {
71 	.prepare = rk808_clkout2_prepare,
72 	.unprepare = rk808_clkout2_unprepare,
73 	.is_prepared = rk808_clkout2_is_prepared,
74 	.recalc_rate = rk808_clkout_recalc_rate,
75 };
76 
77 static struct clk_hw *
78 of_clk_rk808_get(struct of_phandle_args *clkspec, void *data)
79 {
80 	struct rk808_clkout *rk808_clkout = data;
81 	unsigned int idx = clkspec->args[0];
82 
83 	if (idx >= 2) {
84 		pr_err("%s: invalid index %u\n", __func__, idx);
85 		return ERR_PTR(-EINVAL);
86 	}
87 
88 	return idx ? &rk808_clkout->clkout2_hw : &rk808_clkout->clkout1_hw;
89 }
90 
91 static int rk808_clkout_probe(struct platform_device *pdev)
92 {
93 	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
94 	struct i2c_client *client = rk808->i2c;
95 	struct device_node *node = client->dev.of_node;
96 	struct clk_init_data init = {};
97 	struct rk808_clkout *rk808_clkout;
98 	int ret;
99 
100 	rk808_clkout = devm_kzalloc(&client->dev,
101 				    sizeof(*rk808_clkout), GFP_KERNEL);
102 	if (!rk808_clkout)
103 		return -ENOMEM;
104 
105 	rk808_clkout->rk808 = rk808;
106 
107 	init.parent_names = NULL;
108 	init.num_parents = 0;
109 	init.name = "rk808-clkout1";
110 	init.ops = &rk808_clkout1_ops;
111 	rk808_clkout->clkout1_hw.init = &init;
112 
113 	/* optional override of the clockname */
114 	of_property_read_string_index(node, "clock-output-names",
115 				      0, &init.name);
116 
117 	ret = devm_clk_hw_register(&client->dev, &rk808_clkout->clkout1_hw);
118 	if (ret)
119 		return ret;
120 
121 	init.name = "rk808-clkout2";
122 	init.ops = &rk808_clkout2_ops;
123 	rk808_clkout->clkout2_hw.init = &init;
124 
125 	/* optional override of the clockname */
126 	of_property_read_string_index(node, "clock-output-names",
127 				      1, &init.name);
128 
129 	ret = devm_clk_hw_register(&client->dev, &rk808_clkout->clkout2_hw);
130 	if (ret)
131 		return ret;
132 
133 	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_rk808_get,
134 					   rk808_clkout);
135 }
136 
137 static struct platform_driver rk808_clkout_driver = {
138 	.probe = rk808_clkout_probe,
139 	.driver		= {
140 		.name	= "rk808-clkout",
141 	},
142 };
143 
144 module_platform_driver(rk808_clkout_driver);
145 
146 MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
147 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
148 MODULE_LICENSE("GPL");
149 MODULE_ALIAS("platform:rk808-clkout");
150