Merge branch 'origin' into for-linus

Conflicts:
	MAINTAINERS

56 files changed, 17102 insertions, 301 deletions

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 10d3fcffe91..82b34893e5b 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -47,6 +47,8 @@ source "drivers/staging/slicoss/Kconfig"
 
 source "drivers/staging/go7007/Kconfig"
 
+source "drivers/staging/cx25821/Kconfig"
+
 source "drivers/staging/usbip/Kconfig"
 
 source "drivers/staging/winbond/Kconfig"
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index c30093bae62..b1cad0d9ba7 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_STAGING)		+= staging.o
 obj-$(CONFIG_ET131X)		+= et131x/
 obj-$(CONFIG_SLICOSS)		+= slicoss/
 obj-$(CONFIG_VIDEO_GO7007)	+= go7007/
+obj-$(CONFIG_VIDEO_CX25821)	+= cx25821/
 obj-$(CONFIG_USB_IP_COMMON)	+= usbip/
 obj-$(CONFIG_W35UND)		+= winbond/
 obj-$(CONFIG_PRISM2_USB)	+= wlan-ng/
diff --git a/drivers/staging/cx25821/Kconfig b/drivers/staging/cx25821/Kconfig
new file mode 100644
index 00000000000..df7756a95fa
--- /dev/null
+++ b/drivers/staging/cx25821/Kconfig
@@ -0,0 +1,34 @@
+config VIDEO_CX25821
+	tristate "Conexant cx25821 support"
+	depends on DVB_CORE && VIDEO_DEV && PCI && I2C && INPUT
+	select I2C_ALGOBIT
+	select VIDEO_BTCX
+	select VIDEO_TVEEPROM
+	select VIDEO_IR
+	select VIDEOBUF_DVB
+	select VIDEOBUF_DMA_SG
+	select VIDEO_CX25840
+	select VIDEO_CX2341X
+	---help---
+	  This is a video4linux driver for Conexant 25821 based
+	  TV cards.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cx25821
+
+config VIDEO_CX25821_ALSA
+	tristate "Conexant 25821 DMA audio support"
+	depends on VIDEO_CX25821 && SND && EXPERIMENTAL
+	select SND_PCM
+	---help---
+	  This is a video4linux driver for direct (DMA) audio on
+	  Conexant 25821 based capture cards using ALSA.
+
+	  It only works with boards with function 01 enabled.
+	  To check if your board supports, use lspci -n.
+	  If supported, you should see 14f1:8801 or 14f1:8811
+	  PCI device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cx25821-alsa.
+
diff --git a/drivers/staging/cx25821/Makefile b/drivers/staging/cx25821/Makefile
new file mode 100644
index 00000000000..10f87f05d8e
--- /dev/null
+++ b/drivers/staging/cx25821/Makefile
@@ -0,0 +1,14 @@
+cx25821-objs	:= cx25821-core.o cx25821-cards.o cx25821-i2c.o cx25821-gpio.o 				\
+				cx25821-medusa-video.o cx25821-video.o cx25821-video0.o cx25821-video1.o    \
+				cx25821-video2.o cx25821-video3.o cx25821-video4.o cx25821-video5.o         \
+				cx25821-video6.o cx25821-video7.o cx25821-vidups9.o cx25821-vidups10.o      \
+				cx25821-audups11.o cx25821-video-upstream.o cx25821-video-upstream-ch2.o 	\
+				cx25821-audio-upstream.o cx25821-videoioctl.o
+
+obj-$(CONFIG_VIDEO_CX25821) += cx25821.o
+obj-$(CONFIG_VIDEO_CX25821_ALSA) += cx25821-alsa.o
+
+EXTRA_CFLAGS += -Idrivers/media/video
+EXTRA_CFLAGS += -Idrivers/media/common/tuners
+EXTRA_CFLAGS += -Idrivers/media/dvb/dvb-core
+EXTRA_CFLAGS += -Idrivers/media/dvb/frontends
diff --git a/drivers/staging/cx25821/README b/drivers/staging/cx25821/README
new file mode 100644
index 00000000000..a9ba50b9888
--- /dev/null
+++ b/drivers/staging/cx25821/README
@@ -0,0 +1,6 @@
+Todo:
+	- checkpatch.pl cleanups
+	- sparse cleanups
+
+Please send patches to linux-media@vger.kernel.org
+
diff --git a/drivers/staging/cx25821/cx25821-alsa.c b/drivers/staging/cx25821/cx25821-alsa.c
new file mode 100644
index 00000000000..e0eef12759e
--- /dev/null
+++ b/drivers/staging/cx25821/cx25821-alsa.c
@@ -0,0 +1,789 @@
+/*
+ *  Driver for the Conexant CX25821 PCIe bridge
+ *
+ *  Copyright (C) 2009 Conexant Systems Inc.
+ *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
+ *	Based on SAA713x ALSA driver and CX88 driver
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, version 2
+ *
+ *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/vmalloc.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+
+#include <asm/delay.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/control.h>
+#include <sound/initval.h>
+#include <sound/tlv.h>
+
+#include "cx25821.h"
+#include "cx25821-reg.h"
+
+#define AUDIO_SRAM_CHANNEL	SRAM_CH08
+
+#define dprintk(level,fmt, arg...)	if (debug >= level) \
+	printk(KERN_INFO "%s/1: " fmt, chip->dev->name , ## arg)
+
+#define dprintk_core(level,fmt, arg...)	if (debug >= level) \
+	printk(KERN_DEBUG "%s/1: " fmt, chip->dev->name , ## arg)
+
+/****************************************************************************
+	Data type declarations - Can be moded to a header file later
+ ****************************************************************************/
+
+static struct snd_card *snd_cx25821_cards[SNDRV_CARDS];
+static int devno;
+
+struct cx25821_audio_dev {
+	struct cx25821_dev *dev;
+	struct cx25821_dmaqueue q;
+
+	/* pci i/o */
+	struct pci_dev *pci;
+
+	/* audio controls */
+	int irq;
+
+	struct snd_card *card;
+
+	unsigned long iobase;
+	spinlock_t reg_lock;
+	atomic_t count;
+
+	unsigned int dma_size;
+	unsigned int period_size;
+	unsigned int num_periods;
+
+	struct videobuf_dmabuf *dma_risc;
+
+	struct cx25821_buffer *buf;
+
+	struct snd_pcm_substream *substream;
+};
+typedef struct cx25821_audio_dev snd_cx25821_card_t;
+
+
+/****************************************************************************
+			Module global static vars
+ ****************************************************************************/
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
+static int enable[SNDRV_CARDS] = { 1,[1 ... (SNDRV_CARDS - 1)] = 1 };
+
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable cx25821 soundcard. default enabled.");
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for cx25821 capture interface(s).");
+
+/****************************************************************************
+				Module macros
+ ****************************************************************************/
+
+MODULE_DESCRIPTION("ALSA driver module for cx25821 based capture cards");
+MODULE_AUTHOR("Hiep Huynh");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("{{Conexant,25821}");	//"{{Conexant,23881},"
+
+static unsigned int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "enable debug messages");
+
+/****************************************************************************
+			Module specific funtions
+ ****************************************************************************/
+/* Constants taken from cx88-reg.h */
+#define AUD_INT_DN_RISCI1       (1 <<  0)
+#define AUD_INT_UP_RISCI1       (1 <<  1)
+#define AUD_INT_RDS_DN_RISCI1   (1 <<  2)
+#define AUD_INT_DN_RISCI2       (1 <<  4)	/* yes, 3 is skipped */
+#define AUD_INT_UP_RISCI2       (1 <<  5)
+#define AUD_INT_RDS_DN_RISCI2   (1 <<  6)
+#define AUD_INT_DN_SYNC         (1 << 12)
+#define AUD_INT_UP_SYNC         (1 << 13)
+#define AUD_INT_RDS_DN_SYNC     (1 << 14)
+#define AUD_INT_OPC_ERR         (1 << 16)
+#define AUD_INT_BER_IRQ         (1 << 20)
+#define AUD_INT_MCHG_IRQ        (1 << 21)
+#define GP_COUNT_CONTROL_RESET	0x3
+
+#define PCI_MSK_AUD_EXT   (1 <<  4)
+#define PCI_MSK_AUD_INT   (1 <<  3)
+/*
+ * BOARD Specific: Sets audio DMA
+ */
+
+static int _cx25821_start_audio_dma(snd_cx25821_card_t * chip)
+{
+	struct cx25821_buffer *buf = chip->buf;
+	struct cx25821_dev *dev = chip->dev;
+	struct sram_channel *audio_ch =
+	    &cx25821_sram_channels[AUDIO_SRAM_CHANNEL];
+	u32 tmp = 0;
+
+	// enable output on the GPIO 0 for the MCLK ADC (Audio)
+	cx25821_set_gpiopin_direction(chip->dev, 0, 0);
+
+	/* Make sure RISC/FIFO are off before changing FIFO/RISC settings */
+	cx_clear(AUD_INT_DMA_CTL,
+		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
+
+	/* setup fifo + format - out channel */
+	cx25821_sram_channel_setup_audio(chip->dev, audio_ch, buf->bpl,
+					 buf->risc.dma);
+
+	/* sets bpl size */
+	cx_write(AUD_A_LNGTH, buf->bpl);
+
+	/* reset counter */
+	cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);	//GP_COUNT_CONTROL_RESET = 0x3
+	atomic_set(&chip->count, 0);
+
+	//Set the input mode to 16-bit
+	tmp = cx_read(AUD_A_CFG);
+	cx_write(AUD_A_CFG,
+		 tmp | FLD_AUD_DST_PK_MODE | FLD_AUD_DST_ENABLE |
+		 FLD_AUD_CLK_ENABLE);
+
+	//printk(KERN_INFO "DEBUG: Start audio DMA, %d B/line, cmds_start(0x%x)= %d lines/FIFO, %d periods, %d "
+	//      "byte buffer\n", buf->bpl, audio_ch->cmds_start, cx_read(audio_ch->cmds_start + 12)>>1,
+	//      chip->num_periods, buf->bpl * chip->num_periods);
+
+	/* Enables corresponding bits at AUD_INT_STAT */
+	cx_write(AUD_A_INT_MSK,
+		 FLD_AUD_DST_RISCI1 | FLD_AUD_DST_OF | FLD_AUD_DST_SYNC |
+		 FLD_AUD_DST_OPC_ERR);
+
+	/* Clean any pending interrupt bits already set */
+	cx_write(AUD_A_INT_STAT, ~0);
+
+	/* enable audio irqs */
+	cx_set(PCI_INT_MSK, chip->dev->pci_irqmask | PCI_MSK_AUD_INT);
+
+	// Turn on audio downstream fifo and risc enable 0x101
+	tmp = cx_read(AUD_INT_DMA_CTL);
+	cx_set(AUD_INT_DMA_CTL,
+	       tmp | (FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN));
+
+	mdelay(100);
+	return 0;
+}
+
+/*
+ * BOARD Specific: Resets audio DMA
+ */
+static int _cx25821_stop_audio_dma(snd_cx25821_card_t * chip)
+{
+	struct cx25821_dev *dev = chip->dev;
+
+	/* stop dma */
+	cx_clear(AUD_INT_DMA_CTL,
+		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
+
+	/* disable irqs */
+	cx_clear(PCI_INT_MSK, PCI_MSK_AUD_INT);
+	cx_clear(AUD_A_INT_MSK,
+		 AUD_INT_OPC_ERR | AUD_INT_DN_SYNC | AUD_INT_DN_RISCI2 |
+		 AUD_INT_DN_RISCI1);
+
+	return 0;
+}
+
+#define MAX_IRQ_LOOP 50
+
+/*
+ * BOARD Specific: IRQ dma bits
+ */
+static char *cx25821_aud_irqs[32] = {
+	"dn_risci1", "up_risci1", "rds_dn_risc1",	/* 0-2 */
+	NULL,			/* reserved */
+	"dn_risci2", "up_risci2", "rds_dn_risc2",	/* 4-6 */
+	NULL,			/* reserved */
+	"dnf_of", "upf_uf", "rds_dnf_uf",	/* 8-10 */
+	NULL,			/* reserved */
+	"dn_sync", "up_sync", "rds_dn_sync",	/* 12-14 */
+	NULL,			/* reserved */
+	"opc_err", "par_err", "rip_err",	/* 16-18 */
+	"pci_abort", "ber_irq", "mchg_irq"	/* 19-21 */
+};
+
+/*
+ * BOARD Specific: Threats IRQ audio specific calls
+ */
+static void cx25821_aud_irq(snd_cx25821_card_t * chip, u32 status, u32 mask)
+{
+	struct cx25821_dev *dev = chip->dev;
+
+	if (0 == (status & mask)) {
+		return;
+	}
+
+	cx_write(AUD_A_INT_STAT, status);
+	if (debug > 1 || (status & mask & ~0xff))
+		cx25821_print_irqbits(dev->name, "irq aud",
+				      cx25821_aud_irqs,
+				      ARRAY_SIZE(cx25821_aud_irqs), status,
+				      mask);
+
+	/* risc op code error */
+	if (status & AUD_INT_OPC_ERR) {
+		printk(KERN_WARNING "WARNING %s/1: Audio risc op code error\n",
+		       dev->name);
+
+		cx_clear(AUD_INT_DMA_CTL,
+			 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
+		cx25821_sram_channel_dump_audio(dev,
+						&cx25821_sram_channels
+						[AUDIO_SRAM_CHANNEL]);
+	}
+	if (status & AUD_INT_DN_SYNC) {
+		printk(KERN_WARNING "WARNING %s: Downstream sync error!\n",
+		       dev->name);
+		cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
+		return;
+	}
+
+	/* risc1 downstream */
+	if (status & AUD_INT_DN_RISCI1) {
+		atomic_set(&chip->count, cx_read(AUD_A_GPCNT));
+		snd_pcm_period_elapsed(chip->substream);
+	}
+}
+
+/*
+ * BOARD Specific: Handles IRQ calls
+ */
+static irqreturn_t cx25821_irq(int irq, void *dev_id)
+{
+	snd_cx25821_card_t *chip = dev_id;
+	struct cx25821_dev *dev = chip->dev;
+	u32 status, pci_status;
+	u32 audint_status, audint_mask;
+	int loop, handled = 0;
+	int audint_count = 0;
+
+	audint_status = cx_read(AUD_A_INT_STAT);
+	audint_mask = cx_read(AUD_A_INT_MSK);
+	audint_count = cx_read(AUD_A_GPCNT);
+	status = cx_read(PCI_INT_STAT);
+
+	for (loop = 0; loop < 1; loop++) {
+		status = cx_read(PCI_INT_STAT);
+		if (0 == status) {
+			status = cx_read(PCI_INT_STAT);
+			audint_status = cx_read(AUD_A_INT_STAT);
+			audint_mask = cx_read(AUD_A_INT_MSK);
+
+			if (status) {
+				handled = 1;
+				cx_write(PCI_INT_STAT, status);
+
+				cx25821_aud_irq(chip, audint_status,
+						audint_mask);
+				break;
+			} else
+				goto out;
+		}
+
+		handled = 1;
+		cx_write(PCI_INT_STAT, status);
+
+		cx25821_aud_irq(chip, audint_status, audint_mask);
+	}
+
+	pci_status = cx_read(PCI_INT_STAT);
+
+	if (handled)
+		cx_write(PCI_INT_STAT, pci_status);
+
+      out:
+	return IRQ_RETVAL(handled);
+}
+
+static int dsp_buffer_free(snd_cx25821_card_t * chip)
+{
+	BUG_ON(!chip->dma_size);
+
+	dprintk(2, "Freeing buffer\n");
+	videobuf_sg_dma_unmap(&chip->pci->dev, chip->dma_risc);
+	videobuf_dma_free(chip->dma_risc);
+	btcx_riscmem_free(chip->pci, &chip->buf->risc);
+	kfree(chip->buf);
+
+	chip->dma_risc = NULL;
+	chip->dma_size = 0;
+
+	return 0;
+}
+
+/****************************************************************************
+				ALSA PCM Interface
+ ****************************************************************************/
+
+/*
+ * Digital hardware definition
+ */
+#define DEFAULT_FIFO_SIZE	384
+static struct snd_pcm_hardware snd_cx25821_digital_hw = {
+	.info = SNDRV_PCM_INFO_MMAP |
+	    SNDRV_PCM_INFO_INTERLEAVED |
+	    SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID,
+	.formats = SNDRV_PCM_FMTBIT_S16_LE,
+
+	.rates = SNDRV_PCM_RATE_48000,
+	.rate_min = 48000,
+	.rate_max = 48000,
+	.channels_min = 2,
+	.channels_max = 2,
+	/* Analog audio output will be full of clicks and pops if there
+	   are not exactly four lines in the SRAM FIFO buffer.  */
+	.period_bytes_min = DEFAULT_FIFO_SIZE / 3,
+	.period_bytes_max = DEFAULT_FIFO_SIZE / 3,
+	.periods_min = 1,
+	.periods_max = AUDIO_LINE_SIZE,
+	.buffer_bytes_max = (AUDIO_LINE_SIZE * AUDIO_LINE_SIZE),	//128*128 = 16384 = 1024 * 16
+};
+
+/*
+ * audio pcm capture open callback
+ */
+static int snd_cx25821_pcm_open(struct snd_pcm_substream *substream)
+{
+	snd_cx25821_card_t *chip = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+	unsigned int bpl = 0;
+
+	if (!chip) {
+		printk(KERN_ERR "DEBUG: cx25821 can't find device struct."
+		       " Can't proceed with open\n");
+		return -ENODEV;
+	}
+
+	err =
+	    snd_pcm_hw_constraint_pow2(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS);
+	if (err < 0)
+		goto _error;
+
+	chip->substream = substream;
+
+	runtime->hw = snd_cx25821_digital_hw;
+
+	if (cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size !=
+	    DEFAULT_FIFO_SIZE) {
+		bpl = cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size / 3;	//since there are 3 audio Clusters
+		bpl &= ~7;	/* must be multiple of 8 */
+
+		if (bpl > AUDIO_LINE_SIZE) {
+			bpl = AUDIO_LINE_SIZE;
+		}
+		runtime->hw.period_bytes_min = bpl;
+		runtime->hw.period_bytes_max = bpl;
+	}
+
+	return 0;
+      _error:
+	dprintk(1, "Error opening PCM!\n");
+	return err;
+}
+
+/*
+ * audio close callback
+ */
+static int snd_cx25821_close(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+/*
+ * hw_params callback
+ */
+static int snd_cx25821_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *hw_params)
+{
+	snd_cx25821_card_t *chip = snd_pcm_substream_chip(substream);
+	struct videobuf_dmabuf *dma;
+
+	struct cx25821_buffer *buf;
+	int ret;
+
+	if (substream->runtime->dma_area) {
+		dsp_buffer_free(chip);
+		substream->runtime->dma_area = NULL;
+	}
+
+	chip->period_size = params_period_bytes(hw_params);
+	chip->num_periods = params_periods(hw_params);
+	chip->dma_size = chip->period_size * params_periods(hw_params);
+
+	BUG_ON(!chip->dma_size);
+	BUG_ON(chip->num_periods & (chip->num_periods - 1));
+
+	buf = videobuf_sg_alloc(sizeof(*buf));
+	if (NULL == buf)
+		return -ENOMEM;
+
+	if (chip->period_size > AUDIO_LINE_SIZE) {
+		chip->period_size = AUDIO_LINE_SIZE;
+	}
+
+	buf->vb.memory = V4L2_MEMORY_MMAP;
+	buf->vb.field = V4L2_FIELD_NONE;
+	buf->vb.width = chip->period_size;
+	buf->bpl = chip->period_size;
+	buf->vb.height = chip->num_periods;
+	buf->vb.size = chip->dma_size;
+
+	dma = videobuf_to_dma(&buf->vb);
+	videobuf_dma_init(dma);
+
+	ret = videobuf_dma_init_kernel(dma, PCI_DMA_FROMDEVICE,
+				       (PAGE_ALIGN(buf->vb.size) >>
+					PAGE_SHIFT));
+	if (ret < 0)
+		goto error;
+
+	ret = videobuf_sg_dma_map(&chip->pci->dev, dma);
+	if (ret < 0)
+		goto error;
+
+	ret =
+	    cx25821_risc_databuffer_audio(chip->pci, &buf->risc, dma->sglist,
+					  buf->vb.width, buf->vb.height, 1);
+	if (ret < 0) {
+		printk(KERN_INFO
+		       "DEBUG: ERROR after cx25821_risc_databuffer_audio() \n");
+		goto error;
+	}
+
+	/* Loop back to start of program */
+	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
+	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
+	buf->risc.jmp[2] = cpu_to_le32(0);	/* bits 63-32 */
+
+	buf->vb.state = VIDEOBUF_PREPARED;
+
+	chip->buf = buf;
+	chip->dma_risc = dma;
+
+	substream->runtime->dma_area = chip->dma_risc->vmalloc;
+	substream->runtime->dma_bytes = chip->dma_size;
+	substream->runtime->dma_addr = 0;
+
+	return 0;
+
+      error:
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * hw free callback
+ */
+static int snd_cx25821_hw_free(struct snd_pcm_substream *substream)
+{
+	snd_cx25821_card_t *chip = snd_pcm_substream_chip(substream);
+
+	if (substream->runtime->dma_area) {
+		dsp_buffer_free(chip);
+		substream->runtime->dma_area = NULL;
+	}
+
+	return 0;
+}
+
+/*
+ * prepare callback
+ */
+static int snd_cx25821_prepare(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+/*
+ * trigger callback
+ */
+static int snd_cx25821_card_trigger(struct snd_pcm_substream *substream,
+				    int cmd)
+{
+	snd_cx25821_card_t *chip = snd_pcm_substream_chip(substream);
+	int err = 0;
+
+	/* Local interrupts are already disabled by ALSA */
+	spin_lock(&chip->reg_lock);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		err = _cx25821_start_audio_dma(chip);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		err = _cx25821_stop_audio_dma(chip);
+		break;
+	default:
+		err