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