Merge tag 'xtensa-20170612' of git://github.com/jcmvbkbc/linux-xtensa
[linux-2.6-microblaze.git] / drivers / clk / clk-hi655x.c
1 /*
2  * Clock driver for Hi655x
3  *
4  * Copyright (c) 2017, Linaro Ltd.
5  *
6  * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
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 #include <linux/clk-provider.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21 #include <linux/slab.h>
22 #include <linux/mfd/core.h>
23 #include <linux/mfd/hi655x-pmic.h>
24
25 #define HI655X_CLK_BASE HI655X_BUS_ADDR(0x1c)
26 #define HI655X_CLK_SET  BIT(6)
27
28 struct hi655x_clk {
29         struct hi655x_pmic *hi655x;
30         struct clk_hw       clk_hw;
31 };
32
33 static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw,
34                                             unsigned long parent_rate)
35 {
36         return 32768;
37 }
38
39 static int hi655x_clk_enable(struct clk_hw *hw, bool enable)
40 {
41         struct hi655x_clk *hi655x_clk =
42                 container_of(hw, struct hi655x_clk, clk_hw);
43
44         struct hi655x_pmic *hi655x = hi655x_clk->hi655x;
45
46         return regmap_update_bits(hi655x->regmap, HI655X_CLK_BASE,
47                                   HI655X_CLK_SET, enable ? HI655X_CLK_SET : 0);
48 }
49
50 static int hi655x_clk_prepare(struct clk_hw *hw)
51 {
52         return hi655x_clk_enable(hw, true);
53 }
54
55 static void hi655x_clk_unprepare(struct clk_hw *hw)
56 {
57         hi655x_clk_enable(hw, false);
58 }
59
60 static int hi655x_clk_is_prepared(struct clk_hw *hw)
61 {
62         struct hi655x_clk *hi655x_clk =
63                 container_of(hw, struct hi655x_clk, clk_hw);
64         struct hi655x_pmic *hi655x = hi655x_clk->hi655x;
65         int ret;
66         uint32_t val;
67
68         ret = regmap_read(hi655x->regmap, HI655X_CLK_BASE, &val);
69         if (ret < 0)
70                 return ret;
71
72         return val & HI655X_CLK_BASE;
73 }
74
75 static const struct clk_ops hi655x_clk_ops = {
76         .prepare     = hi655x_clk_prepare,
77         .unprepare   = hi655x_clk_unprepare,
78         .is_prepared = hi655x_clk_is_prepared,
79         .recalc_rate = hi655x_clk_recalc_rate,
80 };
81
82 static int hi655x_clk_probe(struct platform_device *pdev)
83 {
84         struct device *parent = pdev->dev.parent;
85         struct hi655x_pmic *hi655x = dev_get_drvdata(parent);
86         struct hi655x_clk *hi655x_clk;
87         const char *clk_name = "hi655x-clk";
88         struct clk_init_data init = {
89                 .name = clk_name,
90                 .ops = &hi655x_clk_ops
91         };
92         int ret;
93
94         hi655x_clk = devm_kzalloc(&pdev->dev, sizeof(*hi655x_clk), GFP_KERNEL);
95         if (!hi655x_clk)
96                 return -ENOMEM;
97
98         of_property_read_string_index(parent->of_node, "clock-output-names",
99                                       0, &clk_name);
100
101         hi655x_clk->clk_hw.init = &init;
102         hi655x_clk->hi655x      = hi655x;
103
104         platform_set_drvdata(pdev, hi655x_clk);
105
106         ret = devm_clk_hw_register(&pdev->dev, &hi655x_clk->clk_hw);
107         if (ret)
108                 return ret;
109
110         return of_clk_add_hw_provider(parent->of_node, of_clk_hw_simple_get,
111                                      &hi655x_clk->clk_hw);
112 }
113
114 static struct platform_driver hi655x_clk_driver = {
115         .probe =  hi655x_clk_probe,
116         .driver         = {
117                 .name   = "hi655x-clk",
118         },
119 };
120
121 module_platform_driver(hi655x_clk_driver);
122
123 MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs");
124 MODULE_AUTHOR("Daniel Lezcano <daniel.lezcano@linaro.org>");
125 MODULE_LICENSE("GPL");
126 MODULE_ALIAS("platform:hi655x-clk");