ASoC: fsl_asrc: Add ASRC ASoC CPU DAI and platform drivers

The Asynchronous Sample Rate Converter (ASRC) converts the sampling rate of a
signal associated with an input clock into a signal associated with a different
output clock. The driver currently works as a Front End of DPCM with other Back
Ends DAI links such as ESAI<->CS42888 and SSI<->WM8962 and SAI. It converts the
original sample rate to a common rate supported by Back Ends for playback while
converts the common rate of Back Ends to a desired rate for capture. It has 3
pairs to support three different substreams within totally 10 channels.
Signed-off-by: NNicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: NVarka Bhadram <varkabhadram@gmail.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/sound/fsl,asrc.txt

+Freescale Asynchronous Sample Rate Converter (ASRC) Controller
+
+The Asynchronous Sample Rate Converter (ASRC) converts the sampling rate of a
+signal associated with an input clock into a signal associated with a different
+output clock. The driver currently works as a Front End of DPCM with other Back
+Ends Audio controller such as ESAI, SSI and SAI. It has three pairs to support
+three substreams within totally 10 channels.
+
+Required properties:
+
+  - compatible		: Contains "fsl,imx35-asrc" or "fsl,imx53-asrc".
+
+  - reg			: Offset and length of the register set for the device.
+
+  - interrupts		: Contains the spdif interrupt.
+
+  - dmas		: Generic dma devicetree binding as described in
+			  Documentation/devicetree/bindings/dma/dma.txt.
+
+  - dma-names		: Contains "rxa", "rxb", "rxc", "txa", "txb" and "txc".
+
+  - clocks		: Contains an entry for each entry in clock-names.
+
+  - clock-names		: Contains the following entries
+	"mem"		  Peripheral access clock to access registers.
+	"ipg"		  Peripheral clock to driver module.
+	"asrck_<0-f>"	  Clock sources for input and output clock.
+
+   - big-endian		: If this property is absent, the little endian mode
+			  will be in use as default. Otherwise, the big endian
+			  mode will be in use for all the device registers.
+
+   - fsl,asrc-rate	: Defines a mutual sample rate used by DPCM Back Ends.
+
+   - fsl,asrc-width	: Defines a mutual sample width used by DPCM Back Ends.
+
+Example:
+
+asrc: asrc@02034000 {
+	compatible = "fsl,imx53-asrc";
+	reg = <0x02034000 0x4000>;
+	interrupts = <0 50 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&clks 107>, <&clks 107>, <&clks 0>,
+	       <&clks 0>, <&clks 0>, <&clks 0>, <&clks 0>,
+	       <&clks 0>, <&clks 0>, <&clks 0>, <&clks 0>,
+	       <&clks 0>, <&clks 0>, <&clks 0>, <&clks 0>,
+	       <&clks 107>, <&clks 0>, <&clks 0>;
+	clock-names = "mem", "ipg", "asrck0",
+		"asrck_1", "asrck_2", "asrck_3", "asrck_4",
+		"asrck_5", "asrck_6", "asrck_7", "asrck_8",
+		"asrck_9", "asrck_a", "asrck_b", "asrck_c",
+		"asrck_d", "asrck_e", "asrck_f";
+	dmas = <&sdma 17 23 1>, <&sdma 18 23 1>, <&sdma 19 23 1>,
+	     <&sdma 20 23 1>, <&sdma 21 23 1>, <&sdma 22 23 1>;
+	dma-names = "rxa", "rxb", "rxc",
+		"txa", "txb", "txc";
+	fsl,asrc-rate  = <48000>;
+	fsl,asrc-width = <16>;
+	status = "okay";
+};

sound/soc/fsl/Kconfig

@@ -2,6 +2,15 @@ menu "SoC Audio for Freescale CPUs"
 
 comment "Common SoC Audio options for Freescale CPUs:"
 
+config SND_SOC_FSL_ASRC
+	tristate "Asynchronous Sample Rate Converter (ASRC) module support"
+	select REGMAP_MMIO
+	help
+	  Say Y if you want to add Asynchronous Sample Rate Converter (ASRC)
+	  support for the Freescale CPUs.
+	  This option is only useful for out-of-tree drivers since
+	  in-tree drivers select it automatically.
+
 config SND_SOC_FSL_SAI
 	tristate "Synchronous Audio Interface (SAI) module support"
 	select REGMAP_MMIO

sound/soc/fsl/Makefile

@@ -11,6 +11,7 @@ snd-soc-p1022-rdk-objs := p1022_rdk.o
 obj-$(CONFIG_SND_SOC_P1022_RDK) += snd-soc-p1022-rdk.o
 
 # Freescale SSI/DMA/SAI/SPDIF Support
+snd-soc-fsl-asrc-objs := fsl_asrc.o fsl_asrc_dma.o
 snd-soc-fsl-sai-objs := fsl_sai.o
 snd-soc-fsl-ssi-y := fsl_ssi.o
 snd-soc-fsl-ssi-$(CONFIG_DEBUG_FS) += fsl_ssi_dbg.o
@@ -18,6 +19,7 @@ snd-soc-fsl-spdif-objs := fsl_spdif.o
 snd-soc-fsl-esai-objs := fsl_esai.o
 snd-soc-fsl-utils-objs := fsl_utils.o
 snd-soc-fsl-dma-objs := fsl_dma.o
+obj-$(CONFIG_SND_SOC_FSL_ASRC) += snd-soc-fsl-asrc.o
 obj-$(CONFIG_SND_SOC_FSL_SAI) += snd-soc-fsl-sai.o
 obj-$(CONFIG_SND_SOC_FSL_SSI) += snd-soc-fsl-ssi.o
 obj-$(CONFIG_SND_SOC_FSL_SPDIF) += snd-soc-fsl-spdif.o

sound/soc/fsl/fsl_asrc.h

+/*
+ * fsl_asrc.h - Freescale ASRC ALSA SoC header file
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * Author: Nicolin Chen <nicoleotsuka@gmail.com>
+ *
+ * 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.
+ */
+
+#ifndef _FSL_ASRC_H
+#define _FSL_ASRC_H
+
+#define IN	0
+#define OUT	1
+
+#define ASRC_DMA_BUFFER_NUM		2
+#define ASRC_INPUTFIFO_THRESHOLD	32
+#define ASRC_OUTPUTFIFO_THRESHOLD	32
+#define ASRC_FIFO_THRESHOLD_MIN		0
+#define ASRC_FIFO_THRESHOLD_MAX		63
+#define ASRC_DMA_BUFFER_SIZE		(1024 * 48 * 4)
+#define ASRC_MAX_BUFFER_SIZE		(1024 * 48)
+#define ASRC_OUTPUT_LAST_SAMPLE		8
+
+#define IDEAL_RATIO_RATE		1000000
+
+#define REG_ASRCTR			0x00
+#define REG_ASRIER			0x04
+#define REG_ASRCNCR			0x0C
+#define REG_ASRCFG			0x10
+#define REG_ASRCSR			0x14
+
+#define REG_ASRCDR1			0x18
+#define REG_ASRCDR2			0x1C
+#define REG_ASRCDR(i)			((i < 2) ? REG_ASRCDR1 : REG_ASRCDR2)
+
+#define REG_ASRSTR			0x20
+#define REG_ASRRA			0x24
+#define REG_ASRRB			0x28
+#define REG_ASRRC			0x2C
+#define REG_ASRPM1			0x40
+#define REG_ASRPM2			0x44
+#define REG_ASRPM3			0x48
+#define REG_ASRPM4			0x4C
+#define REG_ASRPM5			0x50
+#define REG_ASRTFR1			0x54
+#define REG_ASRCCR			0x5C
+
+#define REG_ASRDIA			0x60
+#define REG_ASRDOA			0x64
+#define REG_ASRDIB			0x68
+#define REG_ASRDOB			0x6C
+#define REG_ASRDIC			0x70
+#define REG_ASRDOC			0x74
+#define REG_ASRDI(i)			(REG_ASRDIA + (i << 3))
+#define REG_ASRDO(i)			(REG_ASRDOA + (i << 3))
+#define REG_ASRDx(x, i)			(x == IN ? REG_ASRDI(i) : REG_ASRDO(i))
+
+#define REG_ASRIDRHA			0x80
+#define REG_ASRIDRLA			0x84
+#define REG_ASRIDRHB			0x88
+#define REG_ASRIDRLB			0x8C
+#define REG_ASRIDRHC			0x90
+#define REG_ASRIDRLC			0x94
+#define REG_ASRIDRH(i)			(REG_ASRIDRHA + (i << 3))
+#define REG_ASRIDRL(i)			(REG_ASRIDRLA + (i << 3))
+
+#define REG_ASR76K			0x98
+#define REG_ASR56K			0x9C
+
+#define REG_ASRMCRA			0xA0
+#define REG_ASRFSTA			0xA4
+#define REG_ASRMCRB			0xA8
+#define REG_ASRFSTB			0xAC
+#define REG_ASRMCRC			0xB0
+#define REG_ASRFSTC			0xB4
+#define REG_ASRMCR(i)			(REG_ASRMCRA + (i << 3))
+#define REG_ASRFST(i)			(REG_ASRFSTA + (i << 3))
+
+#define REG_ASRMCR1A			0xC0
+#define REG_ASRMCR1B			0xC4
+#define REG_ASRMCR1C			0xC8
+#define REG_ASRMCR1(i)			(REG_ASRMCR1A + (i << 2))
+
+
+/* REG0 0x00 REG_ASRCTR */
+#define ASRCTR_ATSi_SHIFT(i)		(20 + i)
+#define ASRCTR_ATSi_MASK(i)		(1 << ASRCTR_ATSi_SHIFT(i))
+#define ASRCTR_ATS(i)			(1 << ASRCTR_ATSi_SHIFT(i))
+#define ASRCTR_USRi_SHIFT(i)		(14 + (i << 1))
+#define ASRCTR_USRi_MASK(i)		(1 << ASRCTR_USRi_SHIFT(i))
+#define ASRCTR_USR(i)			(1 << ASRCTR_USRi_SHIFT(i))
+#define ASRCTR_IDRi_SHIFT(i)		(13 + (i << 1))
+#define ASRCTR_IDRi_MASK(i)		(1 << ASRCTR_IDRi_SHIFT(i))
+#define ASRCTR_IDR(i)			(1 << ASRCTR_IDRi_SHIFT(i))
+#define ASRCTR_SRST_SHIFT		4
+#define ASRCTR_SRST_MASK		(1 << ASRCTR_SRST_SHIFT)
+#define ASRCTR_SRST			(1 << ASRCTR_SRST_SHIFT)
+#define ASRCTR_ASRCEi_SHIFT(i)		(1 + i)
+#define ASRCTR_ASRCEi_MASK(i)		(1 << ASRCTR_ASRCEi_SHIFT(i))
+#define ASRCTR_ASRCE(i)			(1 << ASRCTR_ASRCEi_SHIFT(i))
+#define ASRCTR_ASRCEi_ALL_MASK		(0x7 << ASRCTR_ASRCEi_SHIFT(0))
+#define ASRCTR_ASRCEN_SHIFT		0
+#define ASRCTR_ASRCEN_MASK		(1 << ASRCTR_ASRCEN_SHIFT)
+#define ASRCTR_ASRCEN			(1 << ASRCTR_ASRCEN_SHIFT)
+
+/* REG1 0x04 REG_ASRIER */
+#define ASRIER_AFPWE_SHIFT		7
+#define ASRIER_AFPWE_MASK		(1 << ASRIER_AFPWE_SHIFT)
+#define ASRIER_AFPWE			(1 << ASRIER_AFPWE_SHIFT)
+#define ASRIER_AOLIE_SHIFT		6
+#define ASRIER_AOLIE_MASK		(1 << ASRIER_AOLIE_SHIFT)
+#define ASRIER_AOLIE			(1 << ASRIER_AOLIE_SHIFT)
+#define ASRIER_ADOEi_SHIFT(i)		(3 + i)
+#define ASRIER_ADOEi_MASK(i)		(1 << ASRIER_ADOEi_SHIFT(i))
+#define ASRIER_ADOE(i)			(1 << ASRIER_ADOEi_SHIFT(i))
+#define ASRIER_ADIEi_SHIFT(i)		(0 + i)
+#define ASRIER_ADIEi_MASK(i)		(1 << ASRIER_ADIEi_SHIFT(i))
+#define ASRIER_ADIE(i)			(1 << ASRIER_ADIEi_SHIFT(i))
+
+/* REG2 0x0C REG_ASRCNCR */
+#define ASRCNCR_ANCi_SHIFT(i, b)	(b * i)
+#define ASRCNCR_ANCi_MASK(i, b)		(((1 << b) - 1) << ASRCNCR_ANCi_SHIFT(i, b))
+#define ASRCNCR_ANCi(i, v, b)		((v << ASRCNCR_ANCi_SHIFT(i, b)) & ASRCNCR_ANCi_MASK(i, b))
+
+/* REG3 0x10 REG_ASRCFG */
+#define ASRCFG_INIRQi_SHIFT(i)		(21 + i)
+#define ASRCFG_INIRQi_MASK(i)		(1 << ASRCFG_INIRQi_SHIFT(i))
+#define ASRCFG_INIRQi			(1 << ASRCFG_INIRQi_SHIFT(i))
+#define ASRCFG_NDPRi_SHIFT(i)		(18 + i)
+#define ASRCFG_NDPRi_MASK(i)		(1 << ASRCFG_NDPRi_SHIFT(i))
+#define ASRCFG_NDPRi			(1 << ASRCFG_NDPRi_SHIFT(i))
+#define ASRCFG_POSTMODi_SHIFT(i)	(8 + (i << 2))
+#define ASRCFG_POSTMODi_WIDTH		2
+#define ASRCFG_POSTMODi_MASK(i)		(((1 << ASRCFG_POSTMODi_WIDTH) - 1) << ASRCFG_POSTMODi_SHIFT(i))
+#define ASRCFG_POSTMOD(i, v)		((v) << ASRCFG_POSTMODi_SHIFT(i))
+#define ASRCFG_POSTMODi_UP(i)		(0 << ASRCFG_POSTMODi_SHIFT(i))
+#define ASRCFG_POSTMODi_DCON(i)		(1 << ASRCFG_POSTMODi_SHIFT(i))
+#define ASRCFG_POSTMODi_DOWN(i)		(2 << ASRCFG_POSTMODi_SHIFT(i))
+#define ASRCFG_PREMODi_SHIFT(i)		(6 + (i << 2))
+#define ASRCFG_PREMODi_WIDTH		2
+#define ASRCFG_PREMODi_MASK(i)		(((1 << ASRCFG_PREMODi_WIDTH) - 1) << ASRCFG_PREMODi_SHIFT(i))
+#define ASRCFG_PREMOD(i, v)		((v) << ASRCFG_PREMODi_SHIFT(i))
+#define ASRCFG_PREMODi_UP(i)		(0 << ASRCFG_PREMODi_SHIFT(i))
+#define ASRCFG_PREMODi_DCON(i)		(1 << ASRCFG_PREMODi_SHIFT(i))
+#define ASRCFG_PREMODi_DOWN(i)		(2 << ASRCFG_PREMODi_SHIFT(i))
+#define ASRCFG_PREMODi_BYPASS(i)	(3 << ASRCFG_PREMODi_SHIFT(i))
+
+/* REG4 0x14 REG_ASRCSR */
+#define ASRCSR_AxCSi_WIDTH		4
+#define ASRCSR_AxCSi_MASK		((1 << ASRCSR_AxCSi_WIDTH) - 1)
+#define ASRCSR_AOCSi_SHIFT(i)		(12 + (i << 2))
+#define ASRCSR_AOCSi_MASK(i)		(((1 << ASRCSR_AxCSi_WIDTH) - 1) << ASRCSR_AOCSi_SHIFT(i))
+#define ASRCSR_AOCS(i, v)		((v) << ASRCSR_AOCSi_SHIFT(i))
+#define ASRCSR_AICSi_SHIFT(i)		(i << 2)
+#define ASRCSR_AICSi_MASK(i)		(((1 << ASRCSR_AxCSi_WIDTH) - 1) << ASRCSR_AICSi_SHIFT(i))
+#define ASRCSR_AICS(i, v)		((v) << ASRCSR_AICSi_SHIFT(i))
+
+/* REG5&6 0x18 & 0x1C REG_ASRCDR1 & ASRCDR2 */
+#define ASRCDRi_AxCPi_WIDTH		3
+#define ASRCDRi_AICPi_SHIFT(i)		(0 + (i % 2) * 6)
+#define ASRCDRi_AICPi_MASK(i)		(((1 << ASRCDRi_AxCPi_WIDTH) - 1) << ASRCDRi_AICPi_SHIFT(i))
+#define ASRCDRi_AICP(i, v)		((v) << ASRCDRi_AICPi_SHIFT(i))
+#define ASRCDRi_AICDi_SHIFT(i)		(3 + (i % 2) * 6)
+#define ASRCDRi_AICDi_MASK(i)		(((1 << ASRCDRi_AxCPi_WIDTH) - 1) << ASRCDRi_AICDi_SHIFT(i))
+#define ASRCDRi_AICD(i, v)		((v) << ASRCDRi_AICDi_SHIFT(i))
+#define ASRCDRi_AOCPi_SHIFT(i)		((i < 2) ? 12 + i * 6 : 6)
+#define ASRCDRi_AOCPi_MASK(i)		(((1 << ASRCDRi_AxCPi_WIDTH) - 1) << ASRCDRi_AOCPi_SHIFT(i))
+#define ASRCDRi_AOCP(i, v)		((v) << ASRCDRi_AOCPi_SHIFT(i))
+#define ASRCDRi_AOCDi_SHIFT(i)		((i < 2) ? 15 + i * 6 : 9)
+#define ASRCDRi_AOCDi_MASK(i)		(((1 << ASRCDRi_AxCPi_WIDTH) - 1) << ASRCDRi_AOCDi_SHIFT(i))
+#define ASRCDRi_AOCD(i, v)		((v) << ASRCDRi_AOCDi_SHIFT(i))
+
+/* REG7 0x20 REG_ASRSTR */
+#define ASRSTR_DSLCNT_SHIFT		21
+#define ASRSTR_DSLCNT_MASK		(1 << ASRSTR_DSLCNT_SHIFT)
+#define ASRSTR_DSLCNT			(1 << ASRSTR_DSLCNT_SHIFT)
+#define ASRSTR_ATQOL_SHIFT		20
+#define ASRSTR_ATQOL_MASK		(1 << ASRSTR_ATQOL_SHIFT)
+#define ASRSTR_ATQOL			(1 << ASRSTR_ATQOL_SHIFT)
+#define ASRSTR_AOOLi_SHIFT(i)		(17 + i)
+#define ASRSTR_AOOLi_MASK(i)		(1 << ASRSTR_AOOLi_SHIFT(i))
+#define ASRSTR_AOOL(i)			(1 << ASRSTR_AOOLi_SHIFT(i))
+#define ASRSTR_AIOLi_SHIFT(i)		(14 + i)
+#define ASRSTR_AIOLi_MASK(i)		(1 << ASRSTR_AIOLi_SHIFT(i))
+#define ASRSTR_AIOL(i)			(1 << ASRSTR_AIOLi_SHIFT(i))
+#define ASRSTR_AODOi_SHIFT(i)		(11 + i)
+#define ASRSTR_AODOi_MASK(i)		(1 << ASRSTR_AODOi_SHIFT(i))
+#define ASRSTR_AODO(i)			(1 << ASRSTR_AODOi_SHIFT(i))
+#define ASRSTR_AIDUi_SHIFT(i)		(8 + i)
+#define ASRSTR_AIDUi_MASK(i)		(1 << ASRSTR_AIDUi_SHIFT(i))
+#define ASRSTR_AIDU(i)			(1 << ASRSTR_AIDUi_SHIFT(i))
+#define ASRSTR_FPWT_SHIFT		7
+#define ASRSTR_FPWT_MASK		(1 << ASRSTR_FPWT_SHIFT)
+#define ASRSTR_FPWT			(1 << ASRSTR_FPWT_SHIFT)
+#define ASRSTR_AOLE_SHIFT		6
+#define ASRSTR_AOLE_MASK		(1 << ASRSTR_AOLE_SHIFT)
+#define ASRSTR_AOLE			(1 << ASRSTR_AOLE_SHIFT)
+#define ASRSTR_AODEi_SHIFT(i)		(3 + i)
+#define ASRSTR_AODFi_MASK(i)		(1 << ASRSTR_AODEi_SHIFT(i))
+#define ASRSTR_AODF(i)			(1 << ASRSTR_AODEi_SHIFT(i))
+#define ASRSTR_AIDEi_SHIFT(i)		(0 + i)
+#define ASRSTR_AIDEi_MASK(i)		(1 << ASRSTR_AIDEi_SHIFT(i))
+#define ASRSTR_AIDE(i)			(1 << ASRSTR_AIDEi_SHIFT(i))
+
+/* REG10 0x54 REG_ASRTFR1 */
+#define ASRTFR1_TF_BASE_WIDTH		7
+#define ASRTFR1_TF_BASE_SHIFT		6
+#define ASRTFR1_TF_BASE_MASK		(((1 << ASRTFR1_TF_BASE_WIDTH) - 1) << ASRTFR1_TF_BASE_SHIFT)
+#define ASRTFR1_TF_BASE(i)		((i) << ASRTFR1_TF_BASE_SHIFT)
+
+/*
+ * REG22 0xA0 REG_ASRMCRA
+ * REG24 0xA8 REG_ASRMCRB
+ * REG26 0xB0 REG_ASRMCRC
+ */
+#define ASRMCRi_ZEROBUFi_SHIFT		23
+#define ASRMCRi_ZEROBUFi_MASK		(1 << ASRMCRi_ZEROBUFi_SHIFT)
+#define ASRMCRi_ZEROBUFi		(1 << ASRMCRi_ZEROBUFi_SHIFT)
+#define ASRMCRi_EXTTHRSHi_SHIFT		22
+#define ASRMCRi_EXTTHRSHi_MASK		(1 << ASRMCRi_EXTTHRSHi_SHIFT)
+#define ASRMCRi_EXTTHRSHi		(1 << ASRMCRi_EXTTHRSHi_SHIFT)
+#define ASRMCRi_BUFSTALLi_SHIFT		21
+#define ASRMCRi_BUFSTALLi_MASK		(1 << ASRMCRi_BUFSTALLi_SHIFT)
+#define ASRMCRi_BUFSTALLi		(1 << ASRMCRi_BUFSTALLi_SHIFT)
+#define ASRMCRi_BYPASSPOLYi_SHIFT	20
+#define ASRMCRi_BYPASSPOLYi_MASK	(1 << ASRMCRi_BYPASSPOLYi_SHIFT)
+#define ASRMCRi_BYPASSPOLYi		(1 << ASRMCRi_BYPASSPOLYi_SHIFT)
+#define ASRMCRi_OUTFIFO_THRESHOLD_WIDTH	6
+#define ASRMCRi_OUTFIFO_THRESHOLD_SHIFT	12
+#define ASRMCRi_OUTFIFO_THRESHOLD_MASK	(((1 << ASRMCRi_OUTFIFO_THRESHOLD_WIDTH) - 1) << ASRMCRi_OUTFIFO_THRESHOLD_SHIFT)
+#define ASRMCRi_OUTFIFO_THRESHOLD(v)	(((v) << ASRMCRi_OUTFIFO_THRESHOLD_SHIFT) & ASRMCRi_OUTFIFO_THRESHOLD_MASK)
+#define ASRMCRi_RSYNIFi_SHIFT		11
+#define ASRMCRi_RSYNIFi_MASK		(1 << ASRMCRi_RSYNIFi_SHIFT)
+#define ASRMCRi_RSYNIFi			(1 << ASRMCRi_RSYNIFi_SHIFT)
+#define ASRMCRi_RSYNOFi_SHIFT		10
+#define ASRMCRi_RSYNOFi_MASK		(1 << ASRMCRi_RSYNOFi_SHIFT)
+#define ASRMCRi_RSYNOFi			(1 << ASRMCRi_RSYNOFi_SHIFT)
+#define ASRMCRi_INFIFO_THRESHOLD_WIDTH	6
+#define ASRMCRi_INFIFO_THRESHOLD_SHIFT	0
+#define ASRMCRi_INFIFO_THRESHOLD_MASK	(((1 << ASRMCRi_INFIFO_THRESHOLD_WIDTH) - 1) << ASRMCRi_INFIFO_THRESHOLD_SHIFT)
+#define ASRMCRi_INFIFO_THRESHOLD(v)	(((v) << ASRMCRi_INFIFO_THRESHOLD_SHIFT) & ASRMCRi_INFIFO_THRESHOLD_MASK)
+
+/*
+ * REG23 0xA4 REG_ASRFSTA
+ * REG25 0xAC REG_ASRFSTB
+ * REG27 0xB4 REG_ASRFSTC
+ */
+#define ASRFSTi_OAFi_SHIFT		23
+#define ASRFSTi_OAFi_MASK		(1 << ASRFSTi_OAFi_SHIFT)
+#define ASRFSTi_OAFi			(1 << ASRFSTi_OAFi_SHIFT)
+#define ASRFSTi_OUTPUT_FIFO_WIDTH	7
+#define ASRFSTi_OUTPUT_FIFO_SHIFT	12
+#define ASRFSTi_OUTPUT_FIFO_MASK	(((1 << ASRFSTi_OUTPUT_FIFO_WIDTH) - 1) << ASRFSTi_OUTPUT_FIFO_SHIFT)
+#define ASRFSTi_IAEi_SHIFT		11
+#define ASRFSTi_IAEi_MASK		(1 << ASRFSTi_OAFi_SHIFT)
+#define ASRFSTi_IAEi			(1 << ASRFSTi_OAFi_SHIFT)
+#define ASRFSTi_INPUT_FIFO_WIDTH	7
+#define ASRFSTi_INPUT_FIFO_SHIFT	0
+#define ASRFSTi_INPUT_FIFO_MASK		((1 << ASRFSTi_INPUT_FIFO_WIDTH) - 1)
+
+/* REG28 0xC0 & 0xC4 & 0xC8 REG_ASRMCR1i */
+#define ASRMCR1i_IWD_WIDTH		3
+#define ASRMCR1i_IWD_SHIFT		9
+#define ASRMCR1i_IWD_MASK		(((1 << ASRMCR1i_IWD_WIDTH) - 1) << ASRMCR1i_IWD_SHIFT)
+#define ASRMCR1i_IWD(v)			((v) << ASRMCR1i_IWD_SHIFT)
+#define ASRMCR1i_IMSB_SHIFT		8
+#define ASRMCR1i_IMSB_MASK		(1 << ASRMCR1i_IMSB_SHIFT)
+#define ASRMCR1i_IMSB_MSB		(1 << ASRMCR1i_IMSB_SHIFT)
+#define ASRMCR1i_IMSB_LSB		(0 << ASRMCR1i_IMSB_SHIFT)
+#define ASRMCR1i_OMSB_SHIFT		2
+#define ASRMCR1i_OMSB_MASK		(1 << ASRMCR1i_OMSB_SHIFT)
+#define ASRMCR1i_OMSB_MSB		(1 << ASRMCR1i_OMSB_SHIFT)
+#define ASRMCR1i_OMSB_LSB		(0 << ASRMCR1i_OMSB_SHIFT)
+#define ASRMCR1i_OSGN_SHIFT		1
+#define ASRMCR1i_OSGN_MASK		(1 << ASRMCR1i_OSGN_SHIFT)
+#define ASRMCR1i_OSGN			(1 << ASRMCR1i_OSGN_SHIFT)
+#define ASRMCR1i_OW16_SHIFT		0
+#define ASRMCR1i_OW16_MASK		(1 << ASRMCR1i_OW16_SHIFT)
+#define ASRMCR1i_OW16(v)		((v) << ASRMCR1i_OW16_SHIFT)
+
+
+enum asrc_pair_index {
+	ASRC_INVALID_PAIR = -1,
+	ASRC_PAIR_A = 0,
+	ASRC_PAIR_B = 1,
+	ASRC_PAIR_C = 2,
+};
+
+#define ASRC_PAIR_MAX_NUM	(ASRC_PAIR_C + 1)
+
+enum asrc_inclk {
+	INCLK_NONE = 0x03,
+	INCLK_ESAI_RX = 0x00,
+	INCLK_SSI1_RX = 0x01,
+	INCLK_SSI2_RX = 0x02,
+	INCLK_SSI3_RX = 0x07,
+	INCLK_SPDIF_RX = 0x04,
+	INCLK_MLB_CLK = 0x05,
+	INCLK_PAD = 0x06,
+	INCLK_ESAI_TX = 0x08,
+	INCLK_SSI1_TX = 0x09,
+	INCLK_SSI2_TX = 0x0a,
+	INCLK_SSI3_TX = 0x0b,
+	INCLK_SPDIF_TX = 0x0c,
+	INCLK_ASRCK1_CLK = 0x0f,
+};
+
+enum asrc_outclk {
+	OUTCLK_NONE = 0x03,
+	OUTCLK_ESAI_TX = 0x00,
+	OUTCLK_SSI1_TX = 0x01,
+	OUTCLK_SSI2_TX = 0x02,
+	OUTCLK_SSI3_TX = 0x07,
+	OUTCLK_SPDIF_TX = 0x04,
+	OUTCLK_MLB_CLK = 0x05,
+	OUTCLK_PAD = 0x06,
+	OUTCLK_ESAI_RX = 0x08,
+	OUTCLK_SSI1_RX = 0x09,
+	OUTCLK_SSI2_RX = 0x0a,
+	OUTCLK_SSI3_RX = 0x0b,
+	OUTCLK_SPDIF_RX = 0x0c,
+	OUTCLK_ASRCK1_CLK = 0x0f,
+};
+
+#define ASRC_CLK_MAX_NUM	16
+
+enum asrc_word_width {
+	ASRC_WIDTH_24_BIT = 0,
+	ASRC_WIDTH_16_BIT = 1,
+	ASRC_WIDTH_8_BIT = 2,
+};
+
+struct asrc_config {
+	enum asrc_pair_index pair;
+	unsigned int channel_num;
+	unsigned int buffer_num;
+	unsigned int dma_buffer_size;
+	unsigned int input_sample_rate;
+	unsigned int output_sample_rate;
+	enum asrc_word_width input_word_width;
+	enum asrc_word_width output_word_width;
+	enum asrc_inclk inclk;
+	enum asrc_outclk outclk;
+};
+
+struct asrc_req {
+	unsigned int chn_num;
+	enum asrc_pair_index index;
+};
+
+struct asrc_querybuf {
+	unsigned int buffer_index;
+	unsigned int input_length;
+	unsigned int output_length;
+	unsigned long input_offset;
+	unsigned long output_offset;
+};
+
+struct asrc_convert_buffer {
+	void *input_buffer_vaddr;
+	void *output_buffer_vaddr;
+	unsigned int input_buffer_length;
+	unsigned int output_buffer_length;
+};
+
+struct asrc_status_flags {
+	enum asrc_pair_index index;
+	unsigned int overload_error;
+};
+
+enum asrc_error_status {
+	ASRC_TASK_Q_OVERLOAD		= 0x01,
+	ASRC_OUTPUT_TASK_OVERLOAD	= 0x02,
+	ASRC_INPUT_TASK_OVERLOAD	= 0x04,
+	ASRC_OUTPUT_BUFFER_OVERFLOW	= 0x08,
+	ASRC_INPUT_BUFFER_UNDERRUN	= 0x10,
+};
+
+struct dma_block {
+	dma_addr_t dma_paddr;
+	void *dma_vaddr;
+	unsigned int length;
+};
+
+/**
+ * fsl_asrc_pair: ASRC Pair private data
+ *
+ * @asrc_priv: pointer to its parent module
+ * @config: configuration profile
+ * @error: error record
+ * @index: pair index (ASRC_PAIR_A, ASRC_PAIR_B, ASRC_PAIR_C)
+ * @channels: occupied channel number
+ * @desc: input and output dma descriptors
+ * @dma_chan: inputer and output DMA channels
+ * @dma_data: private dma data
+ * @pos: hardware pointer position
+ * @private: pair private area
+ */
+struct fsl_asrc_pair {
+	struct fsl_asrc *asrc_priv;
+	struct asrc_config *config;
+	unsigned int error;
+
+	enum asrc_pair_index index;
+	unsigned int channels;
+
+	struct dma_async_tx_descriptor *desc[2];
+	struct dma_chan *dma_chan[2];
+	struct imx_dma_data dma_data;
+	unsigned int pos;
+
+	void *private;
+};
+
+/**
+ * fsl_asrc_pair: ASRC private data
+ *
+ * @dma_params_rx: DMA parameters for receive channel
+ * @dma_params_tx: DMA parameters for transmit channel
+ * @pdev: platform device pointer
+ * @regmap: regmap handler
+ * @paddr: physical address to the base address of registers
+ * @mem_clk: clock source to access register
+ * @ipg_clk: clock source to drive peripheral
+ * @asrck_clk: clock sources to driver ASRC internal logic
+ * @lock: spin lock for resource protection
+ * @pair: pair pointers
+ * @channel_bits: width of ASRCNCR register for each pair
+ * @channel_avail: non-occupied channel numbers
+ * @asrc_rate: default sample rate for ASoC Back-Ends
+ * @asrc_width: default sample width for ASoC Back-Ends
+ * @name: driver name
+ */
+struct fsl_asrc {
+	struct snd_dmaengine_dai_dma_data dma_params_rx;
+	struct snd_dmaengine_dai_dma_data dma_params_tx;
+	struct platform_device *pdev;
+	struct regmap *regmap;
+	unsigned long paddr;
+	struct clk *mem_clk;
+	struct clk *ipg_clk;
+	struct clk *asrck_clk[ASRC_CLK_MAX_NUM];
+	spinlock_t lock;
+
+	struct fsl_asrc_pair *pair[ASRC_PAIR_MAX_NUM];
+	unsigned int channel_bits;
+	unsigned int channel_avail;
+
+	int asrc_rate;
+	int asrc_width;
+
+	char name[32];
+};
+
+extern struct snd_soc_platform_driver fsl_asrc_platform;
+struct dma_chan *fsl_asrc_get_dma_channel(struct fsl_asrc_pair *pair, bool dir);
+#endif /* _FSL_ASRC_H */

sound/soc/fsl/fsl_asrc_dma.c

+/*
+ * Freescale ASRC ALSA SoC Platform (DMA) driver
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * Author: Nicolin Chen <nicoleotsuka@gmail.com>
+ *
+ * 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.
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/platform_data/dma-imx.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+
+#include "fsl_asrc.h"
+
+#define FSL_ASRC_DMABUF_SIZE	(256 * 1024)
+
+static struct snd_pcm_hardware snd_imx_hardware = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_RESUME,
+	.buffer_bytes_max = FSL_ASRC_DMABUF_SIZE,
+	.period_bytes_min = 128,
+	.period_bytes_max = 65535, /* Limited by SDMA engine */
+	.periods_min = 2,
+	.periods_max = 255,
+	.fifo_size = 0,
+};
+
+static bool filter(struct dma_chan *chan, void *param)
+{
+	if (!imx_dma_is_general_purpose(chan))
+		return false;
+
+	chan->private = param;
+
+	return true;
+}
+
+static void fsl_asrc_dma_complete(void *arg)
+{
+	struct snd_pcm_substream *substream = arg;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	pair->pos += snd_pcm_lib_period_bytes(substream);
+	if (pair->pos >= snd_pcm_lib_buffer_bytes(substream))
+		pair->pos = 0;
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static int fsl_asrc_dma_prepare_and_submit(struct snd_pcm_substream *substream)
+{
+	u8 dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? OUT : IN;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct device *dev = rtd->platform->dev;
+	unsigned long flags = DMA_CTRL_ACK;
+
+	/* Prepare and submit Front-End DMA channel */
+	if (!substream->runtime->no_period_wakeup)
+		flags |= DMA_PREP_INTERRUPT;
+
+	pair->pos = 0;
+	pair->desc[!dir] = dmaengine_prep_dma_cyclic(
+			pair->dma_chan[!dir], runtime->dma_addr,
+			snd_pcm_lib_buffer_bytes(substream),
+			snd_pcm_lib_period_bytes(substream),
+			dir == OUT ? DMA_TO_DEVICE : DMA_FROM_DEVICE, flags);
+	if (!pair->desc[!dir]) {
+		dev_err(dev, "failed to prepare slave DMA for Front-End\n");
+		return -ENOMEM;
+	}
+
+	pair->desc[!dir]->callback = fsl_asrc_dma_complete;
+	pair->desc[!dir]->callback_param = substream;
+
+	dmaengine_submit(pair->desc[!dir]);
+
+	/* Prepare and submit Back-End DMA channel */
+	pair->desc[dir] = dmaengine_prep_dma_cyclic(
+			pair->dma_chan[dir], 0xffff, 64, 64, DMA_DEV_TO_DEV, 0);
+	if (!pair->desc[dir]) {
+		dev_err(dev, "failed to prepare slave DMA for Back-End\n");
+		return -ENOMEM;
+	}
+
+	dmaengine_submit(pair->desc[dir]);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	int ret;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		ret = fsl_asrc_dma_prepare_and_submit(substream);
+		if (ret)
+			return ret;
+		dma_async_issue_pending(pair->dma_chan[IN]);
+		dma_async_issue_pending(pair->dma_chan[OUT]);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		dmaengine_terminate_all(pair->dma_chan[OUT]);
+		dmaengine_terminate_all(pair->dma_chan[IN]);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int fsl_asrc_dma_hw_params(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params *params)
+{
+	enum dma_slave_buswidth buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
+	struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct fsl_asrc *asrc_priv = pair->asrc_priv;
+	struct dma_slave_config config_fe, config_be;
+	enum asrc_pair_index index = pair->index;
+	struct device *dev = rtd->platform->dev;
+	int stream = substream->stream;
+	struct imx_dma_data *tmp_data;
+	struct snd_soc_dpcm *dpcm;
+	struct dma_chan *tmp_chan;
+	struct device *dev_be;
+	u8 dir = tx ? OUT : IN;
+	dma_cap_mask_t mask;
+	int ret;
+
+	/* Fetch the Back-End dma_data from DPCM */
+	list_for_each_entry(dpcm, &rtd->dpcm[stream].be_clients, list_be) {
+		struct snd_soc_pcm_runtime *be = dpcm->be;
+		struct snd_pcm_substream *substream_be;
+		struct snd_soc_dai *dai = be->cpu_dai;
+
+		if (dpcm->fe != rtd)
+			continue;
+
+		substream_be = snd_soc_dpcm_get_substream(be, stream);
+		dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
+		dev_be = dai->dev;
+		break;
+	}
+
+	if (!dma_params_be) {
+		dev_err(dev, "failed to get the substream of Back-End\n");
+		return -EINVAL;
+	}
+
+	/* Override dma_data of the Front-End and config its dmaengine */
+	dma_params_fe = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
+	dma_params_fe->addr = asrc_priv->paddr + REG_ASRDx(!dir, index);
+	dma_params_fe->maxburst = dma_params_be->maxburst;
+
+	pair->dma_chan[!dir] = fsl_asrc_get_dma_channel(pair, !dir);
+	if (!pair->dma_chan[!dir]) {
+		dev_err(dev, "failed to request DMA channel\n");
+		return -EINVAL;
+	}
+
+	memset(&config_fe, 0, sizeof(config_fe));
+	ret = snd_dmaengine_pcm_prepare_slave_config(substream, params, &config_fe);
+	if (ret) {
+		dev_err(dev, "failed to prepare DMA config for Front-End\n");
+		return ret;
+	}
+
+	ret = dmaengine_slave_config(pair->dma_chan[!dir], &config_fe);
+	if (ret) {
+		dev_err(dev, "failed to config DMA channel for Front-End\n");
+		return ret;
+	}
+
+	/* Request and config DMA channel for Back-End */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_CYCLIC, mask);
+
+	/* Get DMA request of Back-End */
+	tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+	tmp_data = tmp_chan->private;
+	pair->dma_data.dma_request = tmp_data->dma_request;
+	dma_release_channel(tmp_chan);
+
+	/* Get DMA request of Front-End */
+	tmp_chan = fsl_asrc_get_dma_channel(pair, dir);
+	tmp_data = tmp_chan->private;
+	pair->dma_data.dma_request2 = tmp_data->dma_request;
+	pair->dma_data.peripheral_type = tmp_data->peripheral_type;
+	pair->dma_data.priority = tmp_data->priority;
+	dma_release_channel(tmp_chan);
+
+	pair->dma_chan[dir] = dma_request_channel(mask, filter, &pair->dma_data);
+	if (!pair->dma_chan[dir]) {
+		dev_err(dev, "failed to request DMA channel for Back-End\n");
+		return -EINVAL;
+	}
+
+	if (asrc_priv->asrc_width == 16)
+		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	else
+		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	config_be.direction = DMA_DEV_TO_DEV;
+	config_be.src_addr_width = buswidth;
+	config_be.src_maxburst = dma_params_be->maxburst;
+	config_be.dst_addr_width = buswidth;
+	config_be.dst_maxburst = dma_params_be->maxburst;
+
+	if (tx) {
+		config_be.src_addr = asrc_priv->paddr + REG_ASRDO(index);
+		config_be.dst_addr = dma_params_be->addr;
+	} else {
+		config_be.dst_addr = asrc_priv->paddr + REG_ASRDI(index);
+		config_be.src_addr = dma_params_be->addr;
+	}
+
+	ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
+	if (ret) {
+		dev_err(dev, "failed to config DMA channel for Back-End\n");
+		return ret;
+	}
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	snd_pcm_set_runtime_buffer(substream, NULL);
+
+	if (pair->dma_chan[IN])
+		dma_release_channel(pair->dma_chan[IN]);
+
+	if (pair->dma_chan[OUT])
+		dma_release_channel(pair->dma_chan[OUT]);
+
+	pair->dma_chan[IN] = NULL;
+	pair->dma_chan[OUT] = NULL;
+
+	return 0;
+}
+
+static int fsl_asrc_dma_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct device *dev = rtd->platform->dev;
+	struct fsl_asrc *asrc_priv = dev_get_drvdata(dev);
+	struct fsl_asrc_pair *pair;
+
+	pair = kzalloc(sizeof(struct fsl_asrc_pair), GFP_KERNEL);
+	if (!pair) {
+		dev_err(dev, "failed to allocate pair\n");
+		return -ENOMEM;
+	}
+
+	pair->asrc_priv = asrc_priv;
+
+	runtime->private_data = pair;
+
+	snd_pcm_hw_constraint_integer(substream->runtime,
+				      SNDRV_PCM_HW_PARAM_PERIODS);
+	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
+
+	return 0;
+}
+
+static int fsl_asrc_dma_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+	struct fsl_asrc *asrc_priv = pair->asrc_priv;
+
+	if (pair && asrc_priv->pair[pair->index] == pair)
+		asrc_priv->pair[pair->index] = NULL;
+
+	kfree(pair);
+
+	return 0;
+}
+
+static snd_pcm_uframes_t fsl_asrc_dma_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct fsl_asrc_pair *pair = runtime->private_data;
+
+	return bytes_to_frames(substream->runtime, pair->pos);
+}
+
+static struct snd_pcm_ops fsl_asrc_dma_pcm_ops = {
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= fsl_asrc_dma_hw_params,
+	.hw_free	= fsl_asrc_dma_hw_free,
+	.trigger	= fsl_asrc_dma_trigger,
+	.open		= fsl_asrc_dma_startup,
+	.close		= fsl_asrc_dma_shutdown,
+	.pointer	= fsl_asrc_dma_pcm_pointer,
+};
+
+static int fsl_asrc_dma_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_card *card = rtd->card->snd_card;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm *pcm = rtd->pcm;
+	int ret, i;
+
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(card->dev, "failed to set DMA mask\n");
+		return ret;
+	}
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_LAST; i++) {
+		substream = pcm->streams[i].substream;
+		if (!substream)
+			continue;
+
+		ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
+				FSL_ASRC_DMABUF_SIZE, &substream->dma_buffer);
+		if (ret) {
+			dev_err(card->dev, "failed to allocate DMA buffer\n");
+			goto err;
+		}
+	}
+
+	return 0;
+
+err:
+	if (--i == 0 && pcm->streams[i].substream)
+		snd_dma_free_pages(&pcm->streams[i].substream->dma_buffer);
+
+	return ret;
+}
+
+static void fsl_asrc_dma_pcm_free(struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	int i;
+
+	for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_LAST; i++) {
+		substream = pcm->streams[i].substream;
+		if (!substream)
+			continue;
+
+		snd_dma_free_pages(&substream->dma_buffer);
+		substream->dma_buffer.area = NULL;
+		substream->dma_buffer.addr = 0;
+	}
+}
+
+struct snd_soc_platform_driver fsl_asrc_platform = {
+	.ops		= &fsl_asrc_dma_pcm_ops,
+	.pcm_new	= fsl_asrc_dma_pcm_new,
+	.pcm_free	= fsl_asrc_dma_pcm_free,
+};
+EXPORT_SYMBOL_GPL(fsl_asrc_platform);