From 894b68e1941fa572a97dc059865e5669ecaa3b4a Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Fri, 17 Jun 2016 13:40:31 +0100 Subject: [PATCH 1/2] dt-bindings: bus: Add documentation for Tegra210 ACONNECT Add binding documentation for the Tegra ACONNECT bus that is part of the Audio Processing Engine (APE) on Tegra210. The ACONNECT bus is used to access devices within the APE subsystem. The APE is located in a separate power domain and so accesses made to the ACONNECT require the power domain to be enabled as well as some platform specific clocks. Signed-off-by: Jon Hunter Acked-by: Rob Herring Signed-off-by: Thierry Reding --- .../bindings/bus/nvidia,tegra210-aconnect.txt | 45 +++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt diff --git a/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt b/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt new file mode 100644 index 000000000000..7ff13be1750b --- /dev/null +++ b/Documentation/devicetree/bindings/bus/nvidia,tegra210-aconnect.txt @@ -0,0 +1,45 @@ +NVIDIA Tegra ACONNECT Bus + +The Tegra ACONNECT bus is an AXI switch which is used to connnect various +components inside the Audio Processing Engine (APE). All CPU accesses to +the APE subsystem go through the ACONNECT via an APB to AXI wrapper. + +Required properties: +- compatible: Must be "nvidia,tegra210-aconnect". +- clocks: Must contain the entries for the APE clock (TEGRA210_CLK_APE), + and APE interface clock (TEGRA210_CLK_APB2APE). +- clock-names: Must contain the names "ape" and "apb2ape" for the corresponding + 'clocks' entries. +- power-domains: Must contain a phandle that points to the audio powergate + (namely 'aud') for Tegra210. +- #address-cells: The number of cells used to represent physical base addresses + in the aconnect address space. Should be 1. +- #size-cells: The number of cells used to represent the size of an address + range in the aconnect address space. Should be 1. +- ranges: Mapping of the aconnect address space to the CPU address space. + +All devices accessed via the ACONNNECT are described by child-nodes. + +Example: + + aconnect@702c0000 { + compatible = "nvidia,tegra210-aconnect"; + clocks = <&tegra_car TEGRA210_CLK_APE>, + <&tegra_car TEGRA210_CLK_APB2APE>; + clock-names = "ape", "apb2ape"; + power-domains = <&pd_audio>; + + #address-cells = <1>; + #size-cells = <1>; + ranges = <0x702c0000 0x0 0x702c0000 0x00040000>; + + status = "disabled"; + + child1 { + ... + }; + + child2 { + ... + }; + }; From 46a88534afb596eb4d9de07ddde778d0e9aa0e3a Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Fri, 17 Jun 2016 13:40:32 +0100 Subject: [PATCH 2/2] 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 Signed-off-by: Thierry Reding --- drivers/bus/Kconfig | 13 ++++ drivers/bus/Makefile | 1 + drivers/bus/tegra-aconnect.c | 112 +++++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+) create mode 100644 drivers/bus/tegra-aconnect.c 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 +#include +#include +#include +#include +#include + +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 "); +MODULE_LICENSE("GPL v2");