sound/soc/meson/axg-fifo.c - linux - Git at Google

 // SPDX-License-Identifier: (GPL-2.0 OR MIT)
 //
 // Copyright (c) 2018 BayLibre, SAS.
 // Author: Jerome Brunet <jbrunet@baylibre.com>

 #include <linux/clk.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/soc-dai.h>

 #include "axg-fifo.h"

 /*
  * This file implements the platform operations common to the playback and
  * capture frontend DAI. The logic behind this two types of fifo is very
  * similar but some difference exist.
  * These differences are handled in the respective DAI drivers
  */

 static struct snd_pcm_hardware axg_fifo_hw = {
 	.info = (SNDRV_PCM_INFO_INTERLEAVED |
 		 SNDRV_PCM_INFO_MMAP |
 		 SNDRV_PCM_INFO_MMAP_VALID |
 		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
 		 SNDRV_PCM_INFO_PAUSE |
 		 SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),
 	.formats = AXG_FIFO_FORMATS,
 	.rate_min = 5512,
 	.rate_max = 192000,
 	.channels_min = 1,
 	.channels_max = AXG_FIFO_CH_MAX,
 	.period_bytes_min = AXG_FIFO_BURST,
 	.period_bytes_max = UINT_MAX,
 	.periods_min = 2,
 	.periods_max = UINT_MAX,

 	/* No real justification for this */
 	.buffer_bytes_max = 1 * 1024 * 1024,
 };

 static struct snd_soc_dai *axg_fifo_dai(struct snd_pcm_substream *ss)
 {
 	struct snd_soc_pcm_runtime *rtd = ss->private_data;

 	return asoc_rtd_to_cpu(rtd, 0);
 }

 static struct axg_fifo *axg_fifo_data(struct snd_pcm_substream *ss)
 {
 	struct snd_soc_dai *dai = axg_fifo_dai(ss);

 	return snd_soc_dai_get_drvdata(dai);
 }

 static struct device *axg_fifo_dev(struct snd_pcm_substream *ss)
 {
 	struct snd_soc_dai *dai = axg_fifo_dai(ss);

 	return dai->dev;
 }

 static void __dma_enable(struct axg_fifo *fifo,  bool enable)
 {
 	regmap_update_bits(fifo->map, FIFO_CTRL0, CTRL0_DMA_EN,
 			   enable ? CTRL0_DMA_EN : 0);
 }

 int axg_fifo_pcm_trigger(struct snd_soc_component *component,
 			 struct snd_pcm_substream *ss, int cmd)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		__dma_enable(fifo, true);
 		break;
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_STOP:
 		__dma_enable(fifo, false);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_trigger);

 snd_pcm_uframes_t axg_fifo_pcm_pointer(struct snd_soc_component *component,
 				       struct snd_pcm_substream *ss)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	struct snd_pcm_runtime *runtime = ss->runtime;
 	unsigned int addr;

 	regmap_read(fifo->map, FIFO_STATUS2, &addr);

 	return bytes_to_frames(runtime, addr - (unsigned int)runtime->dma_addr);
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_pointer);

 int axg_fifo_pcm_hw_params(struct snd_soc_component *component,
 			   struct snd_pcm_substream *ss,
 			   struct snd_pcm_hw_params *params)
 {
 	struct snd_pcm_runtime *runtime = ss->runtime;
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	unsigned int burst_num, period, threshold, irq_en;
 	dma_addr_t end_ptr;

 	period = params_period_bytes(params);

 	/* Setup dma memory pointers */
 	end_ptr = runtime->dma_addr + runtime->dma_bytes - AXG_FIFO_BURST;
 	regmap_write(fifo->map, FIFO_START_ADDR, runtime->dma_addr);
 	regmap_write(fifo->map, FIFO_FINISH_ADDR, end_ptr);

 	/* Setup interrupt periodicity */
 	burst_num = period / AXG_FIFO_BURST;
 	regmap_write(fifo->map, FIFO_INT_ADDR, burst_num);

 	/*
 	 * Start the fifo request on the smallest of the following:
 	 * - Half the fifo size
 	 * - Half the period size
 	 */
 	threshold = min(period / 2, fifo->depth / 2);

 	/*
 	 * With the threshold in bytes, register value is:
 	 * V = (threshold / burst) - 1
 	 */
 	threshold /= AXG_FIFO_BURST;
 	regmap_field_write(fifo->field_threshold,
 			   threshold ? threshold - 1 : 0);

 	/* Enable irq if necessary  */
 	irq_en = runtime->no_period_wakeup ? 0 : FIFO_INT_COUNT_REPEAT;
 	regmap_update_bits(fifo->map, FIFO_CTRL0,
 			   CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT),
 			   CTRL0_INT_EN(irq_en));

 	return 0;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_params);

 int g12a_fifo_pcm_hw_params(struct snd_soc_component *component,
 			    struct snd_pcm_substream *ss,
 			    struct snd_pcm_hw_params *params)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	struct snd_pcm_runtime *runtime = ss->runtime;
 	int ret;

 	ret = axg_fifo_pcm_hw_params(component, ss, params);
 	if (ret)
 		return ret;

 	/* Set the initial memory address of the DMA */
 	regmap_write(fifo->map, FIFO_INIT_ADDR, runtime->dma_addr);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(g12a_fifo_pcm_hw_params);

 int axg_fifo_pcm_hw_free(struct snd_soc_component *component,
 			 struct snd_pcm_substream *ss)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);

 	/* Disable the block count irq */
 	regmap_update_bits(fifo->map, FIFO_CTRL0,
 			   CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT), 0);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_free);

 static void axg_fifo_ack_irq(struct axg_fifo *fifo, u8 mask)
 {
 	regmap_update_bits(fifo->map, FIFO_CTRL1,
 			   CTRL1_INT_CLR(FIFO_INT_MASK),
 			   CTRL1_INT_CLR(mask));

 	/* Clear must also be cleared */
 	regmap_update_bits(fifo->map, FIFO_CTRL1,
 			   CTRL1_INT_CLR(FIFO_INT_MASK),
 			   0);
 }

 static irqreturn_t axg_fifo_pcm_irq_block(int irq, void *dev_id)
 {
 	struct snd_pcm_substream *ss = dev_id;
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	unsigned int status;

 	regmap_read(fifo->map, FIFO_STATUS1, &status);

 	status = STATUS1_INT_STS(status) & FIFO_INT_MASK;
 	if (status & FIFO_INT_COUNT_REPEAT)
 		snd_pcm_period_elapsed(ss);
 	else
 		dev_dbg(axg_fifo_dev(ss), "unexpected irq - STS 0x%02x\n",
 			status);

 	/* Ack irqs */
 	axg_fifo_ack_irq(fifo, status);

 	return IRQ_RETVAL(status);
 }

 int axg_fifo_pcm_open(struct snd_soc_component *component,
 		      struct snd_pcm_substream *ss)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	struct device *dev = axg_fifo_dev(ss);
 	int ret;

 	snd_soc_set_runtime_hwparams(ss, &axg_fifo_hw);

 	/*
 	 * Make sure the buffer and period size are multiple of the FIFO
 	 * burst
 	 */
 	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
 					 SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
 					 AXG_FIFO_BURST);
 	if (ret)
 		return ret;

 	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
 					 SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
 					 AXG_FIFO_BURST);
 	if (ret)
 		return ret;

 	ret = request_irq(fifo->irq, axg_fifo_pcm_irq_block, 0,
 			  dev_name(dev), ss);
 	if (ret)
 		return ret;

 	/* Enable pclk to access registers and clock the fifo ip */
 	ret = clk_prepare_enable(fifo->pclk);
 	if (ret)
 		goto free_irq;

 	/* Setup status2 so it reports the memory pointer */
 	regmap_update_bits(fifo->map, FIFO_CTRL1,
 			   CTRL1_STATUS2_SEL_MASK,
 			   CTRL1_STATUS2_SEL(STATUS2_SEL_DDR_READ));

 	/* Make sure the dma is initially disabled */
 	__dma_enable(fifo, false);

 	/* Disable irqs until params are ready */
 	regmap_update_bits(fifo->map, FIFO_CTRL0,
 			   CTRL0_INT_EN(FIFO_INT_MASK), 0);

 	/* Clear any pending interrupt */
 	axg_fifo_ack_irq(fifo, FIFO_INT_MASK);

 	/* Take memory arbitror out of reset */
 	ret = reset_control_deassert(fifo->arb);
 	if (ret)
 		goto free_clk;

 	return 0;

 free_clk:
 	clk_disable_unprepare(fifo->pclk);
 free_irq:
 	free_irq(fifo->irq, ss);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_open);

 int axg_fifo_pcm_close(struct snd_soc_component *component,
 		       struct snd_pcm_substream *ss)
 {
 	struct axg_fifo *fifo = axg_fifo_data(ss);
 	int ret;

 	/* Put the memory arbitror back in reset */
 	ret = reset_control_assert(fifo->arb);

 	/* Disable fifo ip and register access */
 	clk_disable_unprepare(fifo->pclk);

 	/* remove IRQ */
 	free_irq(fifo->irq, ss);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_close);

 int axg_fifo_pcm_new(struct snd_soc_pcm_runtime *rtd, unsigned int type)
 {
 	struct snd_card *card = rtd->card->snd_card;
 	size_t size = axg_fifo_hw.buffer_bytes_max;

 	snd_pcm_set_managed_buffer(rtd->pcm->streams[type].substream,
 				   SNDRV_DMA_TYPE_DEV, card->dev,
 				   size, size);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(axg_fifo_pcm_new);

 static const struct regmap_config axg_fifo_regmap_cfg = {
 	.reg_bits	= 32,
 	.val_bits	= 32,
 	.reg_stride	= 4,
 	.max_register	= FIFO_CTRL2,
 };

 int axg_fifo_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct axg_fifo_match_data *data;
 	struct axg_fifo *fifo;
 	void __iomem *regs;
 	int ret;

 	data = of_device_get_match_data(dev);
 	if (!data) {
 		dev_err(dev, "failed to match device\n");
 		return -ENODEV;
 	}

 	fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL);
 	if (!fifo)
 		return -ENOMEM;
 	platform_set_drvdata(pdev, fifo);

 	regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);

 	fifo->map = devm_regmap_init_mmio(dev, regs, &axg_fifo_regmap_cfg);
 	if (IS_ERR(fifo->map)) {
 		dev_err(dev, "failed to init regmap: %ld\n",
 			PTR_ERR(fifo->map));
 		return PTR_ERR(fifo->map);
 	}

 	fifo->pclk = devm_clk_get(dev, NULL);
 	if (IS_ERR(fifo->pclk)) {
 		if (PTR_ERR(fifo->pclk) != -EPROBE_DEFER)
 			dev_err(dev, "failed to get pclk: %ld\n",
 				PTR_ERR(fifo->pclk));
 		return PTR_ERR(fifo->pclk);
 	}

 	fifo->arb = devm_reset_control_get_exclusive(dev, NULL);
 	if (IS_ERR(fifo->arb)) {
 		if (PTR_ERR(fifo->arb) != -EPROBE_DEFER)
 			dev_err(dev, "failed to get arb reset: %ld\n",
 				PTR_ERR(fifo->arb));
 		return PTR_ERR(fifo->arb);
 	}

 	fifo->irq = of_irq_get(dev->of_node, 0);
 	if (fifo->irq <= 0) {
 		dev_err(dev, "failed to get irq: %d\n", fifo->irq);
 		return fifo->irq;
 	}

 	fifo->field_threshold =
 		devm_regmap_field_alloc(dev, fifo->map, data->field_threshold);
 	if (IS_ERR(fifo->field_threshold))
 		return PTR_ERR(fifo->field_threshold);

 	ret = of_property_read_u32(dev->of_node, "amlogic,fifo-depth",
 				   &fifo->depth);
 	if (ret) {
 		/* Error out for anything but a missing property */
 		if (ret != -EINVAL)
 			return ret;
 		/*
 		 * If the property is missing, it might be because of an old
 		 * DT. In such case, assume the smallest known fifo depth
 		 */
 		fifo->depth = 256;
 		dev_warn(dev, "fifo depth not found, assume %u bytes\n",
 			 fifo->depth);
 	}

 	return devm_snd_soc_register_component(dev, data->component_drv,
 					       data->dai_drv, 1);
 }
 EXPORT_SYMBOL_GPL(axg_fifo_probe);

 MODULE_DESCRIPTION("Amlogic AXG/G12A fifo driver");
 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: (GPL-2.0 OR MIT)
	//
	// Copyright (c) 2018 BayLibre, SAS.
	// Author: Jerome Brunet <jbrunet@baylibre.com>

	#include <linux/clk.h>
	#include <linux/of_irq.h>
	#include <linux/of_platform.h>
	#include <linux/module.h>
	#include <linux/regmap.h>
	#include <linux/reset.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include <sound/soc-dai.h>

	#include "axg-fifo.h"

	/*
	* This file implements the platform operations common to the playback and
	* capture frontend DAI. The logic behind this two types of fifo is very
	* similar but some difference exist.
	* These differences are handled in the respective DAI drivers
	*/

	static struct snd_pcm_hardware axg_fifo_hw = {
	.info = (SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \|
	SNDRV_PCM_INFO_PAUSE \|
	SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),
	.formats = AXG_FIFO_FORMATS,
	.rate_min = 5512,
	.rate_max = 192000,
	.channels_min = 1,
	.channels_max = AXG_FIFO_CH_MAX,
	.period_bytes_min = AXG_FIFO_BURST,
	.period_bytes_max = UINT_MAX,
	.periods_min = 2,
	.periods_max = UINT_MAX,

	/* No real justification for this */
	.buffer_bytes_max = 1 * 1024 * 1024,
	};

	static struct snd_soc_dai axg_fifo_dai(struct snd_pcm_substream ss)
	{
	struct snd_soc_pcm_runtime *rtd = ss->private_data;

	return asoc_rtd_to_cpu(rtd, 0);
	}

	static struct axg_fifo axg_fifo_data(struct snd_pcm_substream ss)
	{
	struct snd_soc_dai *dai = axg_fifo_dai(ss);

	return snd_soc_dai_get_drvdata(dai);
	}

	static struct device axg_fifo_dev(struct snd_pcm_substream ss)
	{
	struct snd_soc_dai *dai = axg_fifo_dai(ss);

	return dai->dev;
	}

	static void __dma_enable(struct axg_fifo *fifo, bool enable)
	{
	regmap_update_bits(fifo->map, FIFO_CTRL0, CTRL0_DMA_EN,
	enable ? CTRL0_DMA_EN : 0);
	}

	int axg_fifo_pcm_trigger(struct snd_soc_component *component,
	struct snd_pcm_substream *ss, int cmd)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	__dma_enable(fifo, true);
	break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	case SNDRV_PCM_TRIGGER_STOP:
	__dma_enable(fifo, false);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_trigger);

	snd_pcm_uframes_t axg_fifo_pcm_pointer(struct snd_soc_component *component,
	struct snd_pcm_substream *ss)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);
	struct snd_pcm_runtime *runtime = ss->runtime;
	unsigned int addr;

	regmap_read(fifo->map, FIFO_STATUS2, &addr);

	return bytes_to_frames(runtime, addr - (unsigned int)runtime->dma_addr);
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_pointer);

	int axg_fifo_pcm_hw_params(struct snd_soc_component *component,
	struct snd_pcm_substream *ss,
	struct snd_pcm_hw_params *params)
	{
	struct snd_pcm_runtime *runtime = ss->runtime;
	struct axg_fifo *fifo = axg_fifo_data(ss);
	unsigned int burst_num, period, threshold, irq_en;
	dma_addr_t end_ptr;

	period = params_period_bytes(params);

	/* Setup dma memory pointers */
	end_ptr = runtime->dma_addr + runtime->dma_bytes - AXG_FIFO_BURST;
	regmap_write(fifo->map, FIFO_START_ADDR, runtime->dma_addr);
	regmap_write(fifo->map, FIFO_FINISH_ADDR, end_ptr);

	/* Setup interrupt periodicity */
	burst_num = period / AXG_FIFO_BURST;
	regmap_write(fifo->map, FIFO_INT_ADDR, burst_num);

	/*
	* Start the fifo request on the smallest of the following:
	* - Half the fifo size
	* - Half the period size
	*/
	threshold = min(period / 2, fifo->depth / 2);

	/*
	* With the threshold in bytes, register value is:
	* V = (threshold / burst) - 1
	*/
	threshold /= AXG_FIFO_BURST;
	regmap_field_write(fifo->field_threshold,
	threshold ? threshold - 1 : 0);

	/* Enable irq if necessary */
	irq_en = runtime->no_period_wakeup ? 0 : FIFO_INT_COUNT_REPEAT;
	regmap_update_bits(fifo->map, FIFO_CTRL0,
	CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT),
	CTRL0_INT_EN(irq_en));

	return 0;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_params);

	int g12a_fifo_pcm_hw_params(struct snd_soc_component *component,
	struct snd_pcm_substream *ss,
	struct snd_pcm_hw_params *params)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);
	struct snd_pcm_runtime *runtime = ss->runtime;
	int ret;

	ret = axg_fifo_pcm_hw_params(component, ss, params);
	if (ret)
	return ret;

	/* Set the initial memory address of the DMA */
	regmap_write(fifo->map, FIFO_INIT_ADDR, runtime->dma_addr);

	return 0;
	}
	EXPORT_SYMBOL_GPL(g12a_fifo_pcm_hw_params);

	int axg_fifo_pcm_hw_free(struct snd_soc_component *component,
	struct snd_pcm_substream *ss)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);

	/* Disable the block count irq */
	regmap_update_bits(fifo->map, FIFO_CTRL0,
	CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT), 0);

	return 0;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_hw_free);

	static void axg_fifo_ack_irq(struct axg_fifo *fifo, u8 mask)
	{
	regmap_update_bits(fifo->map, FIFO_CTRL1,
	CTRL1_INT_CLR(FIFO_INT_MASK),
	CTRL1_INT_CLR(mask));

	/* Clear must also be cleared */
	regmap_update_bits(fifo->map, FIFO_CTRL1,
	CTRL1_INT_CLR(FIFO_INT_MASK),
	0);
	}

	static irqreturn_t axg_fifo_pcm_irq_block(int irq, void *dev_id)
	{
	struct snd_pcm_substream *ss = dev_id;
	struct axg_fifo *fifo = axg_fifo_data(ss);
	unsigned int status;

	regmap_read(fifo->map, FIFO_STATUS1, &status);

	status = STATUS1_INT_STS(status) & FIFO_INT_MASK;
	if (status & FIFO_INT_COUNT_REPEAT)
	snd_pcm_period_elapsed(ss);
	else
	dev_dbg(axg_fifo_dev(ss), "unexpected irq - STS 0x%02x\n",
	status);

	/* Ack irqs */
	axg_fifo_ack_irq(fifo, status);

	return IRQ_RETVAL(status);
	}

	int axg_fifo_pcm_open(struct snd_soc_component *component,
	struct snd_pcm_substream *ss)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);
	struct device *dev = axg_fifo_dev(ss);
	int ret;

	snd_soc_set_runtime_hwparams(ss, &axg_fifo_hw);

	/*
	* Make sure the buffer and period size are multiple of the FIFO
	* burst
	*/
	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
	SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
	AXG_FIFO_BURST);
	if (ret)
	return ret;

	ret = snd_pcm_hw_constraint_step(ss->runtime, 0,
	SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
	AXG_FIFO_BURST);
	if (ret)
	return ret;

	ret = request_irq(fifo->irq, axg_fifo_pcm_irq_block, 0,
	dev_name(dev), ss);
	if (ret)
	return ret;

	/* Enable pclk to access registers and clock the fifo ip */
	ret = clk_prepare_enable(fifo->pclk);
	if (ret)
	goto free_irq;

	/* Setup status2 so it reports the memory pointer */
	regmap_update_bits(fifo->map, FIFO_CTRL1,
	CTRL1_STATUS2_SEL_MASK,
	CTRL1_STATUS2_SEL(STATUS2_SEL_DDR_READ));

	/* Make sure the dma is initially disabled */
	__dma_enable(fifo, false);

	/* Disable irqs until params are ready */
	regmap_update_bits(fifo->map, FIFO_CTRL0,
	CTRL0_INT_EN(FIFO_INT_MASK), 0);

	/* Clear any pending interrupt */
	axg_fifo_ack_irq(fifo, FIFO_INT_MASK);

	/* Take memory arbitror out of reset */
	ret = reset_control_deassert(fifo->arb);
	if (ret)
	goto free_clk;

	return 0;

	free_clk:
	clk_disable_unprepare(fifo->pclk);
	free_irq:
	free_irq(fifo->irq, ss);
	return ret;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_open);

	int axg_fifo_pcm_close(struct snd_soc_component *component,
	struct snd_pcm_substream *ss)
	{
	struct axg_fifo *fifo = axg_fifo_data(ss);
	int ret;

	/* Put the memory arbitror back in reset */
	ret = reset_control_assert(fifo->arb);

	/* Disable fifo ip and register access */
	clk_disable_unprepare(fifo->pclk);

	/* remove IRQ */
	free_irq(fifo->irq, ss);

	return ret;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_close);

	int axg_fifo_pcm_new(struct snd_soc_pcm_runtime *rtd, unsigned int type)
	{
	struct snd_card *card = rtd->card->snd_card;
	size_t size = axg_fifo_hw.buffer_bytes_max;

	snd_pcm_set_managed_buffer(rtd->pcm->streams[type].substream,
	SNDRV_DMA_TYPE_DEV, card->dev,
	size, size);
	return 0;
	}
	EXPORT_SYMBOL_GPL(axg_fifo_pcm_new);

	static const struct regmap_config axg_fifo_regmap_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.max_register = FIFO_CTRL2,
	};

	int axg_fifo_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	const struct axg_fifo_match_data *data;
	struct axg_fifo *fifo;
	void __iomem *regs;
	int ret;

	data = of_device_get_match_data(dev);
	if (!data) {
	dev_err(dev, "failed to match device\n");
	return -ENODEV;
	}

	fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL);
	if (!fifo)
	return -ENOMEM;
	platform_set_drvdata(pdev, fifo);

	regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(regs))
	return PTR_ERR(regs);

	fifo->map = devm_regmap_init_mmio(dev, regs, &axg_fifo_regmap_cfg);
	if (IS_ERR(fifo->map)) {
	dev_err(dev, "failed to init regmap: %ld\n",
	PTR_ERR(fifo->map));
	return PTR_ERR(fifo->map);
	}

	fifo->pclk = devm_clk_get(dev, NULL);
	if (IS_ERR(fifo->pclk)) {
	if (PTR_ERR(fifo->pclk) != -EPROBE_DEFER)
	dev_err(dev, "failed to get pclk: %ld\n",
	PTR_ERR(fifo->pclk));
	return PTR_ERR(fifo->pclk);
	}

	fifo->arb = devm_reset_control_get_exclusive(dev, NULL);
	if (IS_ERR(fifo->arb)) {
	if (PTR_ERR(fifo->arb) != -EPROBE_DEFER)
	dev_err(dev, "failed to get arb reset: %ld\n",
	PTR_ERR(fifo->arb));
	return PTR_ERR(fifo->arb);
	}

	fifo->irq = of_irq_get(dev->of_node, 0);
	if (fifo->irq <= 0) {
	dev_err(dev, "failed to get irq: %d\n", fifo->irq);
	return fifo->irq;
	}

	fifo->field_threshold =
	devm_regmap_field_alloc(dev, fifo->map, data->field_threshold);
	if (IS_ERR(fifo->field_threshold))
	return PTR_ERR(fifo->field_threshold);

	ret = of_property_read_u32(dev->of_node, "amlogic,fifo-depth",
	&fifo->depth);
	if (ret) {
	/* Error out for anything but a missing property */
	if (ret != -EINVAL)
	return ret;
	/*
	* If the property is missing, it might be because of an old
	* DT. In such case, assume the smallest known fifo depth
	*/
	fifo->depth = 256;
	dev_warn(dev, "fifo depth not found, assume %u bytes\n",
	fifo->depth);
	}

	return devm_snd_soc_register_component(dev, data->component_drv,
	data->dai_drv, 1);
	}
	EXPORT_SYMBOL_GPL(axg_fifo_probe);

	MODULE_DESCRIPTION("Amlogic AXG/G12A fifo driver");
	MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
	MODULE_LICENSE("GPL v2");