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92a72297 | 1 | // SPDX-License-Identifier: GPL-2.0 |
89d463ea GU |
2 | /* |
3 | * Simple Power-Managed Bus Driver | |
4 | * | |
5 | * Copyright (C) 2014-2015 Glider bvba | |
6 | * | |
7 | * This file is subject to the terms and conditions of the GNU General Public | |
8 | * License. See the file "COPYING" in the main directory of this archive | |
9 | * for more details. | |
10 | */ | |
11 | ||
c4583930 | 12 | #include <linux/clk.h> |
89d463ea | 13 | #include <linux/module.h> |
53c5ae63 RH |
14 | #include <linux/of.h> |
15 | #include <linux/of_device.h> | |
89d463ea GU |
16 | #include <linux/of_platform.h> |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/pm_runtime.h> | |
19 | ||
c4583930 LY |
20 | struct simple_pm_bus { |
21 | struct clk_bulk_data *clks; | |
22 | int num_clks; | |
23 | }; | |
24 | ||
89d463ea GU |
25 | static int simple_pm_bus_probe(struct platform_device *pdev) |
26 | { | |
98e96cf8 SK |
27 | const struct device *dev = &pdev->dev; |
28 | const struct of_dev_auxdata *lookup = dev_get_platdata(dev); | |
29 | struct device_node *np = dev->of_node; | |
30 | const struct of_device_id *match; | |
c4583930 | 31 | struct simple_pm_bus *bus; |
98e96cf8 SK |
32 | |
33 | /* | |
34 | * Allow user to use driver_override to bind this driver to a | |
35 | * transparent bus device which has a different compatible string | |
36 | * that's not listed in simple_pm_bus_of_match. We don't want to do any | |
37 | * of the simple-pm-bus tasks for these devices, so return early. | |
38 | */ | |
39 | if (pdev->driver_override) | |
40 | return 0; | |
41 | ||
42 | match = of_match_device(dev->driver->of_match_table, dev); | |
43 | /* | |
44 | * These are transparent bus devices (not simple-pm-bus matches) that | |
45 | * have their child nodes populated automatically. So, don't need to | |
46 | * do anything more. We only match with the device if this driver is | |
47 | * the most specific match because we don't want to incorrectly bind to | |
48 | * a device that has a more specific driver. | |
49 | */ | |
50 | if (match && match->data) { | |
51 | if (of_property_match_string(np, "compatible", match->compatible) == 0) | |
52 | return 0; | |
53 | else | |
54 | return -ENODEV; | |
55 | } | |
89d463ea | 56 | |
c4583930 LY |
57 | bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); |
58 | if (!bus) | |
59 | return -ENOMEM; | |
60 | ||
61 | bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks); | |
62 | if (bus->num_clks < 0) | |
63 | return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n"); | |
64 | ||
65 | dev_set_drvdata(&pdev->dev, bus); | |
66 | ||
89d463ea GU |
67 | dev_dbg(&pdev->dev, "%s\n", __func__); |
68 | ||
69 | pm_runtime_enable(&pdev->dev); | |
70 | ||
71 | if (np) | |
eda080ea | 72 | of_platform_populate(np, NULL, lookup, &pdev->dev); |
89d463ea GU |
73 | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static int simple_pm_bus_remove(struct platform_device *pdev) | |
78 | { | |
98e96cf8 SK |
79 | const void *data = of_device_get_match_data(&pdev->dev); |
80 | ||
81 | if (pdev->driver_override || data) | |
82 | return 0; | |
83 | ||
89d463ea GU |
84 | dev_dbg(&pdev->dev, "%s\n", __func__); |
85 | ||
86 | pm_runtime_disable(&pdev->dev); | |
87 | return 0; | |
88 | } | |
89 | ||
c4583930 LY |
90 | static int simple_pm_bus_runtime_suspend(struct device *dev) |
91 | { | |
92 | struct simple_pm_bus *bus = dev_get_drvdata(dev); | |
93 | ||
94 | clk_bulk_disable_unprepare(bus->num_clks, bus->clks); | |
95 | ||
96 | return 0; | |
97 | } | |
98 | ||
99 | static int simple_pm_bus_runtime_resume(struct device *dev) | |
100 | { | |
101 | struct simple_pm_bus *bus = dev_get_drvdata(dev); | |
102 | int ret; | |
103 | ||
104 | ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks); | |
105 | if (ret) { | |
106 | dev_err(dev, "failed to enable clocks: %d\n", ret); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | static const struct dev_pm_ops simple_pm_bus_pm_ops = { | |
114 | RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL) | |
115 | NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) | |
116 | }; | |
117 | ||
98e96cf8 SK |
118 | #define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */ |
119 | ||
89d463ea GU |
120 | static const struct of_device_id simple_pm_bus_of_match[] = { |
121 | { .compatible = "simple-pm-bus", }, | |
98e96cf8 SK |
122 | { .compatible = "simple-bus", .data = ONLY_BUS }, |
123 | { .compatible = "simple-mfd", .data = ONLY_BUS }, | |
124 | { .compatible = "isa", .data = ONLY_BUS }, | |
125 | { .compatible = "arm,amba-bus", .data = ONLY_BUS }, | |
89d463ea GU |
126 | { /* sentinel */ } |
127 | }; | |
128 | MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match); | |
129 | ||
130 | static struct platform_driver simple_pm_bus_driver = { | |
131 | .probe = simple_pm_bus_probe, | |
132 | .remove = simple_pm_bus_remove, | |
133 | .driver = { | |
134 | .name = "simple-pm-bus", | |
135 | .of_match_table = simple_pm_bus_of_match, | |
c4583930 | 136 | .pm = pm_ptr(&simple_pm_bus_pm_ops), |
89d463ea GU |
137 | }, |
138 | }; | |
139 | ||
140 | module_platform_driver(simple_pm_bus_driver); | |
141 | ||
142 | MODULE_DESCRIPTION("Simple Power-Managed Bus Driver"); | |
143 | MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>"); |