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OpenCloudOS-Kernel/drivers/bus/simple-pm-bus.c

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drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
/*
* 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/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
static int simple_pm_bus_probe(struct platform_device *pdev)
{
drivers: bus: simple-pm-bus: Add support for probing simple bus only devices fw_devlink could end up creating device links for bus only devices. However, bus only devices don't get probed and can block probe() or sync_state() [1] call backs of other devices. To avoid this, probe these devices using the simple-pm-bus driver. However, there are instances of devices that are not simple buses (they get probed by their specific drivers) that also list the "simple-bus" (or other bus only compatible strings) in their compatible property to automatically populate their child devices. We still want these devices to get probed by their specific drivers. So, we make sure this driver only probes devices that are only buses. [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") Cc: stable <stable@vger.kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Tested-by: Saravana Kannan <saravanak@google.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210929000735.585237-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-29 08:07:33 +08:00
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;
/*
* 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;
}
drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
dev_dbg(&pdev->dev, "%s\n", __func__);
pm_runtime_enable(&pdev->dev);
if (np)
drivers: bus: simple-pm-bus: Fix compatibility with simple-bus for auxdata After converting am335x to probe devices with simple-pm-bus I noticed that we are not passing auxdata for of_platform_populate() like we do with simple-bus. While device tree using SoCs should no longer need platform data, there are still quite a few drivers that still need it as can be seen with git grep OF_DEV_AUXDATA. We want to have simple-pm-bus be usable as a replacement for simple-bus also for cases where OF_DEV_AUXDATA is still needed. Let's fix the issue by passing auxdata as platform data to simple-pm-bus. That way the SoCs needing this can pass the auxdata with OF_DEV_AUXDATA. And let's pass the auxdata for omaps to fix the issue for am335x. As an alternative solution, adding simple-pm-bus handling directly to drivers/of/platform.c was considered, but we would still need simple-pm-bus device driver. So passing auxdata as platform data seems like the simplest solution. Fixes: 5a230524f879 ("ARM: dts: Use simple-pm-bus for genpd for am3 l4_wkup") Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Tony Lindgren <tony@atomide.com>
2021-01-15 16:47:17 +08:00
of_platform_populate(np, NULL, lookup, &pdev->dev);
drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
return 0;
}
static int simple_pm_bus_remove(struct platform_device *pdev)
{
drivers: bus: simple-pm-bus: Add support for probing simple bus only devices fw_devlink could end up creating device links for bus only devices. However, bus only devices don't get probed and can block probe() or sync_state() [1] call backs of other devices. To avoid this, probe these devices using the simple-pm-bus driver. However, there are instances of devices that are not simple buses (they get probed by their specific drivers) that also list the "simple-bus" (or other bus only compatible strings) in their compatible property to automatically populate their child devices. We still want these devices to get probed by their specific drivers. So, we make sure this driver only probes devices that are only buses. [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") Cc: stable <stable@vger.kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Tested-by: Saravana Kannan <saravanak@google.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210929000735.585237-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-29 08:07:33 +08:00
const void *data = of_device_get_match_data(&pdev->dev);
if (pdev->driver_override || data)
return 0;
drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
dev_dbg(&pdev->dev, "%s\n", __func__);
pm_runtime_disable(&pdev->dev);
return 0;
}
drivers: bus: simple-pm-bus: Add support for probing simple bus only devices fw_devlink could end up creating device links for bus only devices. However, bus only devices don't get probed and can block probe() or sync_state() [1] call backs of other devices. To avoid this, probe these devices using the simple-pm-bus driver. However, there are instances of devices that are not simple buses (they get probed by their specific drivers) that also list the "simple-bus" (or other bus only compatible strings) in their compatible property to automatically populate their child devices. We still want these devices to get probed by their specific drivers. So, we make sure this driver only probes devices that are only buses. [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") Cc: stable <stable@vger.kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Tested-by: Saravana Kannan <saravanak@google.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210929000735.585237-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-29 08:07:33 +08:00
#define ONLY_BUS ((void *) 1) /* Match if the device is only a bus. */
drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
static const struct of_device_id simple_pm_bus_of_match[] = {
{ .compatible = "simple-pm-bus", },
drivers: bus: simple-pm-bus: Add support for probing simple bus only devices fw_devlink could end up creating device links for bus only devices. However, bus only devices don't get probed and can block probe() or sync_state() [1] call backs of other devices. To avoid this, probe these devices using the simple-pm-bus driver. However, there are instances of devices that are not simple buses (they get probed by their specific drivers) that also list the "simple-bus" (or other bus only compatible strings) in their compatible property to automatically populate their child devices. We still want these devices to get probed by their specific drivers. So, we make sure this driver only probes devices that are only buses. [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") Cc: stable <stable@vger.kernel.org> Cc: Rob Herring <robh+dt@kernel.org> Tested-by: Saravana Kannan <saravanak@google.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210929000735.585237-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-29 08:07:33 +08:00
{ .compatible = "simple-bus", .data = ONLY_BUS },
{ .compatible = "simple-mfd", .data = ONLY_BUS },
{ .compatible = "isa", .data = ONLY_BUS },
{ .compatible = "arm,amba-bus", .data = ONLY_BUS },
drivers: bus: Add Simple Power-Managed Bus Driver Add a driver for transparent busses that don't need a real driver, but where the bus controller is part of a PM domain, or under the control of a functional clock. Typically, the bus controller's PM domain and/or clock must be enabled for child devices connected to the bus (either on-SoC or externally) to function. Hence the sole purpose of this driver is to enable its clock and PM domain (if exist(s)), which are specified in the DT and managed from platform and PM domain code, and to probe for child devices. Due to the child-parent relationship with devices connected to the bus, PM domain and clock state transitions are handled in the correct order. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2015-02-05 18:11:28 +08:00
{ /* 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,
},
};
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");