2 * Simple Power-Managed Bus Driver
4 * Copyright (C) 2014-2015 Glider bvba
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
11 #include <linux/clk.h>
12 #include <linux/module.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
17 struct simple_pm_bus {
18 struct clk_bulk_data *clks;
22 static int simple_pm_bus_probe(struct platform_device *pdev)
24 const struct device *dev = &pdev->dev;
25 const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
26 struct device_node *np = dev->of_node;
27 const struct of_device_id *match;
28 struct simple_pm_bus *bus;
31 * Allow user to use driver_override to bind this driver to a
32 * transparent bus device which has a different compatible string
33 * that's not listed in simple_pm_bus_of_match. We don't want to do any
34 * of the simple-pm-bus tasks for these devices, so return early.
36 if (pdev->driver_override)
39 match = of_match_device(dev->driver->of_match_table, dev);
41 * These are transparent bus devices (not simple-pm-bus matches) that
42 * have their child nodes populated automatically. So, don't need to
43 * do anything more. We only match with the device if this driver is
44 * the most specific match because we don't want to incorrectly bind to
45 * a device that has a more specific driver.
47 if (match && match->data) {
48 if (of_property_match_string(np, "compatible", match->compatible) == 0)
54 bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
58 bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks);
59 if (bus->num_clks < 0)
60 return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");
62 dev_set_drvdata(&pdev->dev, bus);
64 dev_dbg(&pdev->dev, "%s\n", __func__);
66 pm_runtime_enable(&pdev->dev);
69 of_platform_populate(np, NULL, lookup, &pdev->dev);
74 static int simple_pm_bus_remove(struct platform_device *pdev)
76 const void *data = of_device_get_match_data(&pdev->dev);
78 if (pdev->driver_override || data)
81 dev_dbg(&pdev->dev, "%s\n", __func__);
83 pm_runtime_disable(&pdev->dev);
87 static int simple_pm_bus_runtime_suspend(struct device *dev)
89 struct simple_pm_bus *bus = dev_get_drvdata(dev);
91 clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
96 static int simple_pm_bus_runtime_resume(struct device *dev)
98 struct simple_pm_bus *bus = dev_get_drvdata(dev);
101 ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
103 dev_err(dev, "failed to enable clocks: %d\n", ret);
110 static const struct dev_pm_ops simple_pm_bus_pm_ops = {
111 RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)
112 NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
115 #define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */
117 static const struct of_device_id simple_pm_bus_of_match[] = {
118 { .compatible = "simple-pm-bus", },
119 { .compatible = "simple-bus", .data = ONLY_BUS },
120 { .compatible = "simple-mfd", .data = ONLY_BUS },
121 { .compatible = "isa", .data = ONLY_BUS },
122 { .compatible = "arm,amba-bus", .data = ONLY_BUS },
125 MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);
127 static struct platform_driver simple_pm_bus_driver = {
128 .probe = simple_pm_bus_probe,
129 .remove = simple_pm_bus_remove,
131 .name = "simple-pm-bus",
132 .of_match_table = simple_pm_bus_of_match,
133 .pm = pm_ptr(&simple_pm_bus_pm_ops),
137 module_platform_driver(simple_pm_bus_driver);
139 MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
140 MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
141 MODULE_LICENSE("GPL v2");