Commit 0eb6048f authored by Fabio Estevam's avatar Fabio Estevam Committed by Mark Brown

ASoC: fsl_ssi: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: default avatarFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 783ec5e9
/*
* Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
*
* Author: Timur Tabi <timur@freescale.com>
*
* Copyright 2007-2010 Freescale Semiconductor, Inc.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*
*
* Some notes why imx-pcm-fiq is used instead of DMA on some boards:
*
* The i.MX SSI core has some nasty limitations in AC97 mode. While most
* sane processor vendors have a FIFO per AC97 slot, the i.MX has only
* one FIFO which combines all valid receive slots. We cannot even select
* which slots we want to receive. The WM9712 with which this driver
* was developed with always sends GPIO status data in slot 12 which
* we receive in our (PCM-) data stream. The only chance we have is to
* manually skip this data in the FIQ handler. With sampling rates different
* from 48000Hz not every frame has valid receive data, so the ratio
* between pcm data and GPIO status data changes. Our FIQ handler is not
* able to handle this, hence this driver only works with 48000Hz sampling
* rate.
* Reading and writing AC97 registers is another challenge. The core
* provides us status bits when the read register is updated with *another*
* value. When we read the same register two times (and the register still
* contains the same value) these status bits are not set. We work
* around this by not polling these bits but only wait a fixed delay.
*/
// SPDX-License-Identifier: GPL-2.0
//
// Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
//
// Author: Timur Tabi <timur@freescale.com>
//
// Copyright 2007-2010 Freescale Semiconductor, Inc.
//
// Some notes why imx-pcm-fiq is used instead of DMA on some boards:
//
// The i.MX SSI core has some nasty limitations in AC97 mode. While most
// sane processor vendors have a FIFO per AC97 slot, the i.MX has only
// one FIFO which combines all valid receive slots. We cannot even select
// which slots we want to receive. The WM9712 with which this driver
// was developed with always sends GPIO status data in slot 12 which
// we receive in our (PCM-) data stream. The only chance we have is to
// manually skip this data in the FIQ handler. With sampling rates different
// from 48000Hz not every frame has valid receive data, so the ratio
// between pcm data and GPIO status data changes. Our FIQ handler is not
// able to handle this, hence this driver only works with 48000Hz sampling
// rate.
// Reading and writing AC97 registers is another challenge. The core
// provides us status bits when the read register is updated with *another*
// value. When we read the same register two times (and the register still
// contains the same value) these status bits are not set. We work
// around this by not polling these bits but only wait a fixed delay.
#include <linux/init.h>
#include <linux/io.h>
......
/* SPDX-License-Identifier: GPL-2.0 */
/*
* fsl_ssi.h - ALSA SSI interface for the Freescale MPC8610 and i.MX SoC
*
* Author: Timur Tabi <timur@freescale.com>
*
* Copyright 2007-2008 Freescale Semiconductor, Inc. This file is licensed
* under the terms of the GNU General Public License version 2. This
* program is licensed "as is" without any warranty of any kind, whether
* express or implied.
* Copyright 2007-2008 Freescale Semiconductor, Inc.
*/
#ifndef _MPC8610_I2S_H
......
/*
* Freescale SSI ALSA SoC Digital Audio Interface (DAI) debugging functions
*
* Copyright 2014 Markus Pargmann <mpa@pengutronix.de>, Pengutronix
*
* Splitted from fsl_ssi.c
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
// SPDX-License-Identifier: GPL-2.0
//
// Freescale SSI ALSA SoC Digital Audio Interface (DAI) debugging functions
//
// Copyright 2014 Markus Pargmann <mpa@pengutronix.de>, Pengutronix
//
// Split from fsl_ssi.c
#include <linux/debugfs.h>
#include <linux/device.h>
......
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