diff options
Diffstat (limited to 'drivers/bus/simple-pm-bus.c')
| -rw-r--r-- | drivers/bus/simple-pm-bus.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/bus/simple-pm-bus.c b/drivers/bus/simple-pm-bus.c new file mode 100644 index 0000000000..aafcc481de --- /dev/null +++ b/drivers/bus/simple-pm-bus.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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.h> +#include <linux/of_device.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>"); |