xref: /openbmc/linux/drivers/clk/clk-rk808.c (revision c819e2cf)
1 /*
2  * Clkout driver for Rockchip RK808
3  *
4  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
5  *
6  * Author:Chris Zhong <zyw@rock-chips.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  */
17 
18 #include <linux/clk.h>
19 #include <linux/clk-provider.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/platform_device.h>
23 #include <linux/mfd/rk808.h>
24 #include <linux/i2c.h>
25 
26 #define RK808_NR_OUTPUT 2
27 
28 struct rk808_clkout {
29 	struct rk808 *rk808;
30 	struct clk_onecell_data clk_data;
31 	struct clk_hw		clkout1_hw;
32 	struct clk_hw		clkout2_hw;
33 };
34 
35 static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
36 					      unsigned long parent_rate)
37 {
38 	return 32768;
39 }
40 
41 static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
42 {
43 	struct rk808_clkout *rk808_clkout = container_of(hw,
44 							 struct rk808_clkout,
45 							 clkout2_hw);
46 	struct rk808 *rk808 = rk808_clkout->rk808;
47 
48 	return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
49 				  CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
50 }
51 
52 static int rk808_clkout2_prepare(struct clk_hw *hw)
53 {
54 	return rk808_clkout2_enable(hw, true);
55 }
56 
57 static void rk808_clkout2_unprepare(struct clk_hw *hw)
58 {
59 	rk808_clkout2_enable(hw, false);
60 }
61 
62 static int rk808_clkout2_is_prepared(struct clk_hw *hw)
63 {
64 	struct rk808_clkout *rk808_clkout = container_of(hw,
65 							 struct rk808_clkout,
66 							 clkout2_hw);
67 	struct rk808 *rk808 = rk808_clkout->rk808;
68 	uint32_t val;
69 
70 	int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
71 
72 	if (ret < 0)
73 		return ret;
74 
75 	return (val & CLK32KOUT2_EN) ? 1 : 0;
76 }
77 
78 static const struct clk_ops rk808_clkout1_ops = {
79 	.recalc_rate = rk808_clkout_recalc_rate,
80 };
81 
82 static const struct clk_ops rk808_clkout2_ops = {
83 	.prepare = rk808_clkout2_prepare,
84 	.unprepare = rk808_clkout2_unprepare,
85 	.is_prepared = rk808_clkout2_is_prepared,
86 	.recalc_rate = rk808_clkout_recalc_rate,
87 };
88 
89 static int rk808_clkout_probe(struct platform_device *pdev)
90 {
91 	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
92 	struct i2c_client *client = rk808->i2c;
93 	struct device_node *node = client->dev.of_node;
94 	struct clk_init_data init = {};
95 	struct clk **clk_table;
96 	struct rk808_clkout *rk808_clkout;
97 
98 	rk808_clkout = devm_kzalloc(&client->dev,
99 				    sizeof(*rk808_clkout), GFP_KERNEL);
100 	if (!rk808_clkout)
101 		return -ENOMEM;
102 
103 	rk808_clkout->rk808 = rk808;
104 
105 	clk_table = devm_kcalloc(&client->dev, RK808_NR_OUTPUT,
106 				 sizeof(struct clk *), GFP_KERNEL);
107 	if (!clk_table)
108 		return -ENOMEM;
109 
110 	init.flags = CLK_IS_ROOT;
111 	init.parent_names = NULL;
112 	init.num_parents = 0;
113 	init.name = "rk808-clkout1";
114 	init.ops = &rk808_clkout1_ops;
115 	rk808_clkout->clkout1_hw.init = &init;
116 
117 	/* optional override of the clockname */
118 	of_property_read_string_index(node, "clock-output-names",
119 				      0, &init.name);
120 
121 	clk_table[0] = devm_clk_register(&client->dev,
122 					 &rk808_clkout->clkout1_hw);
123 	if (IS_ERR(clk_table[0]))
124 		return PTR_ERR(clk_table[0]);
125 
126 	init.name = "rk808-clkout2";
127 	init.ops = &rk808_clkout2_ops;
128 	rk808_clkout->clkout2_hw.init = &init;
129 
130 	/* optional override of the clockname */
131 	of_property_read_string_index(node, "clock-output-names",
132 				      1, &init.name);
133 
134 	clk_table[1] = devm_clk_register(&client->dev,
135 					 &rk808_clkout->clkout2_hw);
136 	if (IS_ERR(clk_table[1]))
137 		return PTR_ERR(clk_table[1]);
138 
139 	rk808_clkout->clk_data.clks = clk_table;
140 	rk808_clkout->clk_data.clk_num = RK808_NR_OUTPUT;
141 
142 	return of_clk_add_provider(node, of_clk_src_onecell_get,
143 				   &rk808_clkout->clk_data);
144 }
145 
146 static int rk808_clkout_remove(struct platform_device *pdev)
147 {
148 	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
149 	struct i2c_client *client = rk808->i2c;
150 	struct device_node *node = client->dev.of_node;
151 
152 	of_clk_del_provider(node);
153 
154 	return 0;
155 }
156 
157 static struct platform_driver rk808_clkout_driver = {
158 	.probe = rk808_clkout_probe,
159 	.remove = rk808_clkout_remove,
160 	.driver		= {
161 		.name	= "rk808-clkout",
162 	},
163 };
164 
165 module_platform_driver(rk808_clkout_driver);
166 
167 MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
168 MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
169 MODULE_LICENSE("GPL");
170 MODULE_ALIAS("platform:rk808-clkout");
171