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/*
* Simple Power-Managed Bus Driver
*
* Copyright (C) 2014-2015 Glider bvba
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
struct simple_pm_bus {
struct clk_bulk_data *clks;
int num_clks;
};
static int simple_pm_bus_probe(struct platform_device *pdev)
{
const struct device *dev = &pdev->dev;
const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
struct device_node *np = dev->of_node;
const struct of_device_id *match;
struct simple_pm_bus *bus;
/*
* Allow user to use driver_override to bind this driver to a
* transparent bus device which has a different compatible string
* that's not listed in simple_pm_bus_of_match. We don't want to do any
* of the simple-pm-bus tasks for these devices, so return early.
*/
if (pdev->driver_override)
return 0;
match = of_match_device(dev->driver->of_match_table, dev);
/*
* These are transparent bus devices (not simple-pm-bus matches) that
* have their child nodes populated automatically. So, don't need to
* do anything more. We only match with the device if this driver is
* the most specific match because we don't want to incorrectly bind to
* a device that has a more specific driver.
*/
if (match && match->data) {
if (of_property_match_string(np, "compatible", match->compatible) == 0)
return 0;
else
return -ENODEV;
}
bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
bus->num_clks = devm_clk_bulk_get_all(&pdev->dev, &bus->clks);
if (bus->num_clks < 0)
return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");
dev_set_drvdata(&pdev->dev, bus);
dev_dbg(&pdev->dev, "%s\n", __func__);
pm_runtime_enable(&pdev->dev);
if (np)
of_platform_populate(np, NULL, lookup, &pdev->dev);
return 0;
}
static int simple_pm_bus_remove(struct platform_device *pdev)
{
const void *data = of_device_get_match_data(&pdev->dev);
if (pdev->driver_override || data)
return 0;
dev_dbg(&pdev->dev, "%s\n", __func__);
pm_runtime_disable(&pdev->dev);
return 0;
}
static int simple_pm_bus_runtime_suspend(struct device *dev)
{
struct simple_pm_bus *bus = dev_get_drvdata(dev);
clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
return 0;
}
static int simple_pm_bus_runtime_resume(struct device *dev)
{
struct simple_pm_bus *bus = dev_get_drvdata(dev);
int ret;
ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);
if (ret) {
dev_err(dev, "failed to enable clocks: %d\n", ret);
return ret;
}
return 0;
}
static const struct dev_pm_ops simple_pm_bus_pm_ops = {
RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)
NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
};
#define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */
static const struct of_device_id simple_pm_bus_of_match[] = {
{ .compatible = "simple-pm-bus", },
{ .compatible = "simple-bus", .data = ONLY_BUS },
{ .compatible = "simple-mfd", .data = ONLY_BUS },
{ .compatible = "isa", .data = ONLY_BUS },
{ .compatible = "arm,amba-bus", .data = ONLY_BUS },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);
static struct platform_driver simple_pm_bus_driver = {
.probe = simple_pm_bus_probe,
.remove = simple_pm_bus_remove,
.driver = {
.name = "simple-pm-bus",
.of_match_table = simple_pm_bus_of_match,
.pm = pm_ptr(&simple_pm_bus_pm_ops),
},
};
module_platform_driver(simple_pm_bus_driver);
MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_LICENSE("GPL v2");
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