On Fri, Dec 17, 2010 at 02:41:26PM -0700, Stephen Warren wrote:
CCing in Liam and not cutting any text.
> The DAS (Digital Audio Switch) is a mux/crossbar which sits between
> the DACs (Digital Audio Controllers) and the DAPs (Digital Audio
Someone wasn't having their best day ever when they named the digital
audio controller, were they? :P
Reading this it's essentially just exporting point to point switches
within the DAS block. This really feels like it ought to be represented
as a CODEC driver to give runtime flexibility to userspace to control
the mux - it looks like the AP part of the system streams data into this
block which then has very flexible switching on to the externally
connected audio devices.
> Ports). Audio data may be routed between DACs and DAPs in various
> combinations as required by board design/application.
>
> Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
> ---
> sound/soc/tegra/Makefile | 5 +
> sound/soc/tegra/tegra_das.c | 264 +++++++++++++++++++++++++++++++++++++++++++
> sound/soc/tegra/tegra_das.h | 119 +++++++++++++++++++
> 3 files changed, 388 insertions(+), 0 deletions(-)
> create mode 100644 sound/soc/tegra/tegra_das.c
> create mode 100644 sound/soc/tegra/tegra_das.h
>
> diff --git a/sound/soc/tegra/Makefile b/sound/soc/tegra/Makefile
> index e69de29..ea6b8bb 100644
> --- a/sound/soc/tegra/Makefile
> +++ b/sound/soc/tegra/Makefile
> @@ -0,0 +1,5 @@
> +# Tegra platform Support
> +snd-soc-tegra-das-objs := tegra_das.o
> +
> +obj-$(CONFIG_SND_TEGRA_SOC) += snd-soc-tegra-das.o
> +
> diff --git a/sound/soc/tegra/tegra_das.c b/sound/soc/tegra/tegra_das.c
> new file mode 100644
> index 0000000..ec9920a
> --- /dev/null
> +++ b/sound/soc/tegra/tegra_das.c
> @@ -0,0 +1,264 @@
> +/*
> + * tegra_das.c - Tegra DAS driver
> + *
> + * Author: Stephen Warren <swarren@xxxxxxxxxx>
> + * Copyright (C) 2010 - NVIDIA, Inc.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/debugfs.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/seq_file.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +
> +#include <mach/iomap.h>
> +
> +#include "tegra_das.h"
> +
> +#define DRV_NAME "tegra-das"
> +
> +static struct tegra_das *das;
> +
> +static inline void tegra_das_write(u32 reg, u32 val)
> +{
> + __raw_writel(val, das->regs + reg);
> +}
> +
> +static inline u32 tegra_das_read(u32 reg)
> +{
> + return __raw_readl(das->regs + reg);
> +}
> +
> +int tegra_das_configure_dap_for_dac(int dap, int dac)
> +{
> + u32 addr;
> + u32 reg;
> +
> + if (!das)
> + return -ENODEV;
> +
> + addr = TEGRA_DAS_DAP_CTRL_SEL +
> + (dap * TEGRA_DAS_DAP_CTRL_SEL_STRIDE);
> + reg = dac << TEGRA_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P;
> +
> + tegra_das_write(addr, reg);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tegra_das_configure_dap_for_dac);
ASoC core is all EXPORT_SYMBOL_GPL(). While this doesn't link directly
to it it'd still be better to be consistent.
It also feels like you might want a name more like _connect for clarity?
> +int tegra_das_configure_dap_for_dap(int dap, int otherdap, int master,
> + int sdata1rx, int sdata2rx)
> +{
> + u32 addr;
> + u32 reg;
> +
> + if (!das)
> + return -ENODEV;
> +
> + addr = TEGRA_DAS_DAP_CTRL_SEL +
> + (dap * TEGRA_DAS_DAP_CTRL_SEL_STRIDE);
> + reg = otherdap << TEGRA_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P |
> + !!sdata2rx << TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_P |
> + !!sdata1rx << TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_P |
> + !!master << TEGRA_DAS_DAP_CTRL_SEL_DAP_MS_SEL_P;
> +
> + tegra_das_write(addr, reg);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tegra_das_configure_dap_for_dap);
> +
> +int tegra_das_configure_dac(int dac, int dap)
The others are all configure_foo_for_bar...
> +{
> + u32 addr;
> + u32 reg;
> +
> + if (!das)
> + return -ENODEV;
> +
> + addr = TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL +
> + (dac * TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE);
> + reg = dap << TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P |
> + dap << TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P |
> + dap << TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P;
> +
> + tegra_das_write(addr, reg);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tegra_das_configure_dac);
> +
> +#ifdef CONFIG_DEBUG_FS
> +static int tegra_das_show(struct seq_file *s, void *unused)
> +{
> + int i;
> + u32 addr;
> + u32 reg;
> +
> + for (i = 0; i < TEGRA_DAS_DAP_CTRL_SEL_COUNT; i++) {
> + addr = TEGRA_DAS_DAP_CTRL_SEL +
> + (i * TEGRA_DAS_DAP_CTRL_SEL_STRIDE);
> + reg = tegra_das_read(addr);
> + seq_printf(s, "TEGRA_DAS_DAP_CTRL_SEL[%d] = %08x\n", i, reg);
> + }
> +
> + for (i = 0; i < TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_COUNT; i++) {
> + addr = TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL +
> + (i * TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE);
> + reg = tegra_das_read(addr);
> + seq_printf(s, "TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL[%d] = %08x\n",
> + i, reg);
> + }
> +
> + return 0;
> +}
> +
> +static int tegra_das_debug_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, tegra_das_show, inode->i_private);
> +}
> +
> +static const struct file_operations tegra_das_debug_fops = {
> + .open = tegra_das_debug_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = single_release,
> +};
> +
> +static void tegra_das_debug_add(struct tegra_das *das)
> +{
> + das->debug = debugfs_create_file(DRV_NAME, S_IRUGO, NULL, das,
> + &tegra_das_debug_fops);
I'd expect this to live under the ASoC structure in debugfs, not that it
really matters.
> +}
> +
> +static void tegra_das_debug_remove(struct tegra_das *das)
> +{
> + if (das->debug)
> + debugfs_remove(das->debug);
> +}
> +#else
> +static inline void tegra_das_debug_add(struct tegra_das *das)
> +{
> +}
> +
> +static inline void tegra_das_debug_remove(struct tegra_das *das)
> +{
> +}
> +#endif
> +
> +static int __devinit tegra_das_probe(struct platform_device *pdev)
> +{
> + struct resource *res, *region;
> + int ret = 0;
> +
> + if (das)
> + return -ENODEV;
> +
> + das = kzalloc(sizeof(struct tegra_das), GFP_KERNEL);
> + if (!das) {
> + dev_err(&pdev->dev, "Can't allocate tegra_das\n");
> + ret = -ENOMEM;
> + goto exit;
> + }
> + das->dev = &pdev->dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "No memory resource\n");
> + ret = -ENODEV;
> + goto err_free;
> + }
> +
> + region = request_mem_region(res->start, resource_size(res),
> + pdev->name);
> + if (!region) {
> + dev_err(&pdev->dev, "Memory region already claimed\n");
> + ret = -EBUSY;
> + goto err_free;
> + }
> +
> + das->regs = ioremap(res->start, resource_size(res));
> + if (!das->regs) {
> + dev_err(&pdev->dev, "ioremap failed\n");
> + ret = -ENOMEM;
> + goto err_release;
> + }
> +
> + tegra_das_debug_add(das);
> +
> + platform_set_drvdata(pdev, das);
> +
> + return 0;
> +
> +err_release:
> + release_mem_region(res->start, resource_size(res));
> +err_free:
> + kfree(das);
> + das = 0;
> +exit:
> + return ret;
> +}
> +
> +static int __devexit tegra_das_remove(struct platform_device *pdev)
> +{
> + struct resource *res;
> +
> + if (!das)
> + return -ENODEV;
> +
> + platform_set_drvdata(pdev, NULL);
> +
> + tegra_das_debug_remove(das);
> +
> + iounmap(das->regs);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + release_mem_region(res->start, resource_size(res));
> +
> + kfree(das);
> + das = 0;
> +
> + return 0;
> +}
> +
> +static struct platform_driver tegra_das_driver = {
> + .probe = tegra_das_probe,
> + .remove = __devexit_p(tegra_das_remove),
> + .driver = {
> + .name = DRV_NAME,
> + },
> +};
> +
> +static int __init tegra_das_modinit(void)
> +{
> + return platform_driver_register(&tegra_das_driver);
> +}
> +module_init(tegra_das_modinit);
> +
> +static void __exit tegra_das_modexit(void)
> +{
> + platform_driver_unregister(&tegra_das_driver);
> +}
> +module_exit(tegra_das_modexit);
> +
> +MODULE_AUTHOR("Stephen Warren <swarren@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Tegra DAS driver");
> +MODULE_LICENSE("GPL");
> diff --git a/sound/soc/tegra/tegra_das.h b/sound/soc/tegra/tegra_das.h
> new file mode 100644
> index 0000000..98c0a60
> --- /dev/null
> +++ b/sound/soc/tegra/tegra_das.h
> @@ -0,0 +1,119 @@
> +/*
> + * tegra_das.h - Definitions for Tegra DAS driver
> + *
> + * Author: Stephen Warren <swarren@xxxxxxxxxx>
> + * Copyright (C) 2010 - NVIDIA, Inc.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#ifndef __TEGRA_DAS_H__
> +#define __TEGRA_DAS_H__
> +
> +/* Register TEGRA_DAS_DAP_CTRL_SEL */
> +#define TEGRA_DAS_DAP_CTRL_SEL 0x00
> +#define TEGRA_DAS_DAP_CTRL_SEL_COUNT 5
> +#define TEGRA_DAS_DAP_CTRL_SEL_STRIDE 4
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_MS_SEL_P 31
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_MS_SEL_S 1
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_P 30
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_S 1
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_P 29
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_S 1
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P 0
> +#define TEGRA_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_S 5
> +
> +/* Values for field TEGRA_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL */
> +#define TEGRA_DAS_DAP_SEL_DAC1 0
> +#define TEGRA_DAS_DAP_SEL_DAC2 1
> +#define TEGRA_DAS_DAP_SEL_DAC3 2
> +#define TEGRA_DAS_DAP_SEL_DAP1 16
> +#define TEGRA_DAS_DAP_SEL_DAP2 17
> +#define TEGRA_DAS_DAP_SEL_DAP3 18
> +#define TEGRA_DAS_DAP_SEL_DAP4 19
> +#define TEGRA_DAS_DAP_SEL_DAP5 20
> +
> +/* Register TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL */
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL 0x40
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_COUNT 3
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE 4
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P 28
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_S 4
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P 24
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_S 4
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P 0
> +#define TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_S 4
> +
> +/*
> + * Values for:
> + * TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL
> + * TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL
> + * TEGRA_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL
> + */
> +#define TEGRA_DAS_DAC_SEL_DAP1 0
> +#define TEGRA_DAS_DAC_SEL_DAP2 1
> +#define TEGRA_DAS_DAC_SEL_DAP3 2
> +#define TEGRA_DAS_DAC_SEL_DAP4 3
> +#define TEGRA_DAS_DAC_SEL_DAP5 4
> +
> +struct tegra_das {
> + struct device *dev;
> + void __iomem *regs;
> + struct dentry *debug;
> +};
> +
> +/*
> + * Terminology:
> + * DAS: Digital audio switch (HW module controlled by this driver)
> + * DAP: Digital audio port (port/pins on Tegra device)
> + * DAC: Digital audio controller (e.g. I2S or AC97 controller elsewhere)
> + *
> + * The Tegra DAS is a mux/cross-bar which can connect each DAP to a specific
> + * DAC, or another DAP. When DAPs are connected, one must be the master and
> + * one the slave. Each DAC allows selection of a specific DAP for input, to
> + * cater for the case where N DAPs are connected to 1 DAC for broadcast
> + * output.
> + *
> + * This driver is dumb; no attempt is made to ensure that a valid routing
> + * configuration is programmed.
> + */
> +
> +/*
> + * Configure a DAP to connect to a DAC
> + * dap: DAP ID to configure: 0..4
> + * dac: DAC to connect to: TEGRA_DAS_DAP_SEL_DAC*
> + */
> +extern int tegra_das_configure_dap_for_dac(int dap, int dac);
> +
> +/*
> + * Configure a DAP to connect to another DAP
> + * dap: DAP ID to configure: 0..4
> + * otherdap: DAP to connect to: TEGRA_DAS_DAP_SEL_DAP*
> + * master: Is this DAP the master (1) or slave (0)
> + * sdata1rx: Is this DAP's SDATA1 pin RX (1) or TX (0)
> + * sdata2rx: Is this DAP's SDATA2 pin RX (1) or TX (0)
> + */
> +extern int tegra_das_configure_dap_for_dap(int dap, int otherdap, int master,
> + int sdata1rx, int sdata2rx);
> +
> +/*
> + * Configure a DAC to receive input from a DAP
> + * dac: DAC ID to configure: 0..3
> + * dap: DAP to receive input from: TEGRA_DAS_DAC_SEL_DAP*
> + */
> +extern int tegra_das_configure_dac(int dac, int dap);
> +
> +#endif
> --
> 1.7.0.4
> nvpublic
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