Merge tag 'tegra-for-4.8-bus' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/drivers

bus: NVIDIA Tegra ACONNECT support

Adds support for the Tegra ACONNECT bus that's used to access the APE
(audio processing engine) on Tegra X1.

* tag 'tegra-for-4.8-bus' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  bus: Add support for Tegra ACONNECT
  dt-bindings: bus: Add documentation for Tegra210 ACONNECT

Signed-off-by: Olof Johansson <olof@lixom.net>

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");