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linux/drivers/bus/tegra-aconnect.c

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bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
/*
* Tegra ACONNECT Bus Driver
*
* Copyright (C) 2016, NVIDIA CORPORATION. All rights reserved.
*
* 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>
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
struct tegra_aconnect {
struct clk *ape_clk;
struct clk *apb2ape_clk;
};
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
static int tegra_aconnect_probe(struct platform_device *pdev)
{
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
struct tegra_aconnect *aconnect;
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
if (!pdev->dev.of_node)
return -EINVAL;
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
aconnect = devm_kzalloc(&pdev->dev, sizeof(struct tegra_aconnect),
GFP_KERNEL);
if (!aconnect)
return -ENOMEM;
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
aconnect->ape_clk = devm_clk_get(&pdev->dev, "ape");
if (IS_ERR(aconnect->ape_clk)) {
dev_err(&pdev->dev, "Can't retrieve ape clock\n");
return PTR_ERR(aconnect->ape_clk);
}
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
aconnect->apb2ape_clk = devm_clk_get(&pdev->dev, "apb2ape");
if (IS_ERR(aconnect->apb2ape_clk)) {
dev_err(&pdev->dev, "Can't retrieve apb2ape clock\n");
return PTR_ERR(aconnect->apb2ape_clk);
}
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
dev_set_drvdata(&pdev->dev, aconnect);
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
pm_runtime_enable(&pdev->dev);
of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");
return 0;
}
bus: tegra-aconnect: Convert to platform remove callback returning void The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Link: https://lore.kernel.org/r/20231109202830.4124591-9-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-11-09 20:28:38 +00:00
static void tegra_aconnect_remove(struct platform_device *pdev)
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
{
pm_runtime_disable(&pdev->dev);
}
static int tegra_aconnect_runtime_resume(struct device *dev)
{
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
int ret;
ret = clk_prepare_enable(aconnect->ape_clk);
if (ret) {
dev_err(dev, "ape clk_enable failed: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(aconnect->apb2ape_clk);
if (ret) {
clk_disable_unprepare(aconnect->ape_clk);
dev_err(dev, "apb2ape clk_enable failed: %d\n", ret);
return ret;
}
return 0;
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
}
static int tegra_aconnect_runtime_suspend(struct device *dev)
{
bus: tegra-aconnect: use devm_clk_*() helpers aconnect bus driver is using pm_clk_*() interface for managing clocks. With this, clocks seem to be always ON. This happens on Tegra devices which use BPMP co-processor to manage clock resources, where clocks are enabled during prepare phase. This is necessary because calls to BPMP are always blocking. When pm_clk_*() interface is used on such Tegra devices, clock prepare count is not balanced till driver remove() gets executed and hence clocks are seen ON always. Thus this patch replaces pm_clk_*() with devm_clk_*() framework. Suggested-by: Mohan Kumar D <mkumard@nvidia.com> Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com> Signed-off-by: Sameer Pujar <spujar@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:58 +00:00
struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
clk_disable_unprepare(aconnect->ape_clk);
clk_disable_unprepare(aconnect->apb2ape_clk);
return 0;
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
}
static const struct dev_pm_ops tegra_aconnect_pm_ops = {
SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
tegra_aconnect_runtime_resume, NULL)
bus: tegra-aconnect: add system sleep callbacks pm_runtime_force_suspend() and pm_runtime_force_resume() are used as system sleep noirq suspend and resume callbacks. If the driver is active till late suspend, where runtime PM cannot run, force suspend is essential for the device. This makes sure that the device is put into low power state during system wide PM transitions to sleep states. Signed-off-by: Sameer Pujar <spujar@nvidia.com> Acked-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2019-03-13 04:41:59 +00:00
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
};
static const struct of_device_id tegra_aconnect_of_match[] = {
{ .compatible = "nvidia,tegra210-aconnect", },
{ }
};
MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);
static struct platform_driver tegra_aconnect_driver = {
.probe = tegra_aconnect_probe,
bus: tegra-aconnect: Convert to platform remove callback returning void The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Link: https://lore.kernel.org/r/20231109202830.4124591-9-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-11-09 20:28:38 +00:00
.remove_new = tegra_aconnect_remove,
bus: Add support for Tegra ACONNECT Add a bus driver for the Tegra ACONNECT which is used to interface to various devices within the Audio Processing Engine (APE). The purpose of the bus driver is to register child devices that are accessed via the ACONNECT bus and through the device parent child relationship, ensure that the appropriate power domain and clocks are enabled for the ACONNECT when any of the child devices are active. Hence, the ACONNECT driver simply enables runtime-pm for the ACONNECT device so that when a child device is resumed, it will enable the power-domain and clocks associated with the ACONNECT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-06-17 12:40:32 +00:00
.driver = {
.name = "tegra-aconnect",
.of_match_table = tegra_aconnect_of_match,
.pm = &tegra_aconnect_pm_ops,
},
};
module_platform_driver(tegra_aconnect_driver);
MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
MODULE_LICENSE("GPL v2");
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