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authorJon Hunter <jonathanh@nvidia.com>2016-06-17 13:40:32 +0100
committerThierry Reding <treding@nvidia.com>2016-07-01 16:35:43 +0200
commit46a88534afb596eb4d9de07ddde778d0e9aa0e3a (patch)
tree4f20528a8c3ccb44194dde98eaf6027f5d01934c /drivers/bus
parent894b68e1941fa572a97dc059865e5669ecaa3b4a (diff)
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>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/Kconfig13
-rw-r--r--drivers/bus/Makefile1
-rw-r--r--drivers/bus/tegra-aconnect.c112
3 files changed, 126 insertions, 0 deletions
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index c5a7de9bc783..3b205e212337 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -132,6 +132,19 @@ config SUNXI_RSB
with various RSB based devices, such as AXP223, AXP8XX PMICs,
and AC100/AC200 ICs.
+# TODO: This uses pm_clk_*() symbols that aren't exported in v4.7 and hence
+# the driver will fail to build as a module. However there are patches to
+# address that queued for v4.8, so this can be turned into a tristate symbol
+# after v4.8-rc1.
+config TEGRA_ACONNECT
+ bool "Tegra ACONNECT Bus Driver"
+ depends on ARCH_TEGRA_210_SOC
+ depends on OF && PM
+ select PM_CLK
+ help
+ Driver for the Tegra ACONNECT bus which is used to interface with
+ the devices inside the Audio Processing Engine (APE) for Tegra210.
+
config UNIPHIER_SYSTEM_BUS
tristate "UniPhier System Bus driver"
depends on ARCH_UNIPHIER && OF
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index ccff007ee7e8..ac84cc4348e3 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -17,5 +17,6 @@ obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o
obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o
obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o
obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
+obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o
obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
diff --git a/drivers/bus/tegra-aconnect.c b/drivers/bus/tegra-aconnect.c
new file mode 100644
index 000000000000..7e4104b74fa8
--- /dev/null
+++ b/drivers/bus/tegra-aconnect.c
@@ -0,0 +1,112 @@
+/*
+ * 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_clock.h>
+#include <linux/pm_runtime.h>
+
+static int tegra_aconnect_add_clock(struct device *dev, char *name)
+{
+ struct clk *clk;
+ int ret;
+
+ clk = clk_get(dev, name);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "%s clock not found\n", name);
+ return PTR_ERR(clk);
+ }
+
+ ret = pm_clk_add_clk(dev, clk);
+ if (ret)
+ clk_put(clk);
+
+ return ret;
+}
+
+static int tegra_aconnect_probe(struct platform_device *pdev)
+{
+ int ret;
+
+ if (!pdev->dev.of_node)
+ return -EINVAL;
+
+ ret = pm_clk_create(&pdev->dev);
+ if (ret)
+ return ret;
+
+ ret = tegra_aconnect_add_clock(&pdev->dev, "ape");
+ if (ret)
+ goto clk_destroy;
+
+ ret = tegra_aconnect_add_clock(&pdev->dev, "apb2ape");
+ if (ret)
+ goto clk_destroy;
+
+ 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;
+
+clk_destroy:
+ pm_clk_destroy(&pdev->dev);
+
+ return ret;
+}
+
+static int tegra_aconnect_remove(struct platform_device *pdev)
+{
+ pm_runtime_disable(&pdev->dev);
+
+ pm_clk_destroy(&pdev->dev);
+
+ return 0;
+}
+
+static int tegra_aconnect_runtime_resume(struct device *dev)
+{
+ return pm_clk_resume(dev);
+}
+
+static int tegra_aconnect_runtime_suspend(struct device *dev)
+{
+ return pm_clk_suspend(dev);
+}
+
+static const struct dev_pm_ops tegra_aconnect_pm_ops = {
+ SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
+ tegra_aconnect_runtime_resume, NULL)
+};
+
+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,
+ .remove = tegra_aconnect_remove,
+ .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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