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1// SPDX-License-Identifier: GPL-2.02/*3 * Simple Power-Managed Bus Driver4 *5 * Copyright (C) 2014-2015 Glider bvba6 *7 * This file is subject to the terms and conditions of the GNU General Public8 * License. See the file "COPYING" in the main directory of this archive9 * for more details.10 */11 12#include <linux/clk.h>13#include <linux/module.h>14#include <linux/of.h>15#include <linux/of_device.h>16#include <linux/of_platform.h>17#include <linux/platform_device.h>18#include <linux/pm_runtime.h>19 20struct simple_pm_bus {21 struct clk_bulk_data *clks;22 int num_clks;23};24 25static int simple_pm_bus_probe(struct platform_device *pdev)26{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;31 struct simple_pm_bus *bus;32 33 /*34 * Allow user to use driver_override to bind this driver to a35 * transparent bus device which has a different compatible string36 * that's not listed in simple_pm_bus_of_match. We don't want to do any37 * 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) that45 * have their child nodes populated automatically. So, don't need to46 * do anything more. We only match with the device if this driver is47 * the most specific match because we don't want to incorrectly bind to48 * 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 else54 return -ENODEV;55 }56 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 67 dev_dbg(&pdev->dev, "%s\n", __func__);68 69 pm_runtime_enable(&pdev->dev);70 71 if (np)72 of_platform_populate(np, NULL, lookup, &pdev->dev);73 74 return 0;75}76 77static void simple_pm_bus_remove(struct platform_device *pdev)78{79 const void *data = of_device_get_match_data(&pdev->dev);80 81 if (pdev->driver_override || data)82 return;83 84 dev_dbg(&pdev->dev, "%s\n", __func__);85 86 pm_runtime_disable(&pdev->dev);87}88 89static int simple_pm_bus_runtime_suspend(struct device *dev)90{91 struct simple_pm_bus *bus = dev_get_drvdata(dev);92 93 clk_bulk_disable_unprepare(bus->num_clks, bus->clks);94 95 return 0;96}97 98static int simple_pm_bus_runtime_resume(struct device *dev)99{100 struct simple_pm_bus *bus = dev_get_drvdata(dev);101 int ret;102 103 ret = clk_bulk_prepare_enable(bus->num_clks, bus->clks);104 if (ret) {105 dev_err(dev, "failed to enable clocks: %d\n", ret);106 return ret;107 }108 109 return 0;110}111 112static const struct dev_pm_ops simple_pm_bus_pm_ops = {113 RUNTIME_PM_OPS(simple_pm_bus_runtime_suspend, simple_pm_bus_runtime_resume, NULL)114 NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)115};116 117#define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */118 119static const struct of_device_id simple_pm_bus_of_match[] = {120 { .compatible = "simple-pm-bus", },121 { .compatible = "simple-bus", .data = ONLY_BUS },122 { .compatible = "simple-mfd", .data = ONLY_BUS },123 { .compatible = "isa", .data = ONLY_BUS },124 { .compatible = "arm,amba-bus", .data = ONLY_BUS },125 { /* sentinel */ }126};127MODULE_DEVICE_TABLE(of, simple_pm_bus_of_match);128 129static struct platform_driver simple_pm_bus_driver = {130 .probe = simple_pm_bus_probe,131 .remove_new = simple_pm_bus_remove,132 .driver = {133 .name = "simple-pm-bus",134 .of_match_table = simple_pm_bus_of_match,135 .pm = pm_ptr(&simple_pm_bus_pm_ops),136 },137};138 139module_platform_driver(simple_pm_bus_driver);140 141MODULE_DESCRIPTION("Simple Power-Managed Bus Driver");142MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");143