text: /**
   * Freescale P1022DS ALSA SoC Machine driver
   *
   * Author: Timur Tabi <timur@freescale.com>
   *
   * Copyright 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.
   */
  
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/of_device.h>
  #include <linux/slab.h>
  #include <sound/soc.h>
  #include <asm/fsl_guts.h>
  
  #include "fsl_dma.h"
  #include "fsl_ssi.h"
  
  /* P1022-specific PMUXCR and DMUXCR bit definitions */
  
  #define CCSR_GUTS_PMUXCR_UART0_I2C1_MASK	0x0001c000
  #define CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI	0x00010000
  #define CCSR_GUTS_PMUXCR_UART0_I2C1_SSI		0x00018000
  
  #define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK	0x00000c00
  #define CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI	0x00000000
  
  #define CCSR_GUTS_DMUXCR_PAD	1	/* DMA controller/channel set to pad */
  #define CCSR_GUTS_DMUXCR_SSI	2	/* DMA controller/channel set to SSI */
  
  /*
   * Set the DMACR register in the GUTS
   *
   * The DMACR register determines the source of initiated transfers for each
   * channel on each DMA controller.  Rather than have a bunch of repetitive
   * macros for the bit patterns, we just have a function that calculates
   * them.
   *
   * guts: Pointer to GUTS structure
   * co: The DMA controller (0 or 1)
   * ch: The channel on the DMA controller (0, 1, 2, or 3)
   * device: The device to set as the target (CCSR_GUTS_DMUXCR_xxx)
   */
  static inline void guts_set_dmuxcr(struct ccsr_guts_85xx __iomem *guts,
  	unsigned int co, unsigned int ch, unsigned int device)
  {
  	unsigned int shift = 16 + (8 * (1 - co) + 2 * (3 - ch));
  
  	clrsetbits_be32(&guts->dmuxcr, 3 << shift, device << shift);
  }
  
  /* There's only one global utilities register */
  static phys_addr_t guts_phys;
  
  #define DAI_NAME_SIZE	32
  
  /**
   * machine_data: machine-specific ASoC device data
   *
   * This structure contains data for a single sound platform device on an
   * P1022 DS.  Some of the data is taken from the device tree.
   */
  struct machine_data {
  	struct snd_soc_dai_link dai[2];
  	struct snd_soc_card card;
  	unsigned int dai_format;
  	unsigned int codec_clk_direction;
  	unsigned int cpu_clk_direction;
  	unsigned int clk_frequency;
  	unsigned int ssi_id;		/* 0 = SSI1, 1 = SSI2, etc */
  	unsigned int dma_id[2];		/* 0 = DMA1, 1 = DMA2, etc */
  	unsigned int dma_channel_id[2]; /* 0 = ch 0, 1 = ch 1, etc*/
  	char codec_name[DAI_NAME_SIZE];
  	char platform_name[2][DAI_NAME_SIZE]; /* One for each DMA channel */
  };
  
  /**
   * p1022_ds_machine_probe: initialize the board
   *
   * This function is used to initialize the board-specific hardware.
   *
   * Here we program the DMACR and PMUXCR registers.
   */
  static int p1022_ds_machine_probe(struct snd_soc_card *card)
  {
  	struct machine_data *mdata =
  		container_of(card, struct machine_data, card);
  	struct ccsr_guts_85xx __iomem *guts;
  
  	guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
  	if (!guts) {
  		dev_err(card->dev, "could not map global utilities\n");
  		return -ENOMEM;
  	}
  
  	/* Enable SSI Tx signal */
  	clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK,
  			CCSR_GUTS_PMUXCR_UART0_I2C1_UART0_SSI);
  
  	/* Enable SSI Rx signal */
  	clrsetbits_be32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK,
  			CCSR_GUTS_PMUXCR_SSI_DMA_TDM_SSI);
  
  	/* Enable DMA Channel for SSI */
  	guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0],
  			CCSR_GUTS_DMUXCR_SSI);
  
  	guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1],
  			CCSR_GUTS_DMUXCR_SSI);
  
  	iounmap(guts);
  
  	return 0;
  }
  
  /**
   * p1022_ds_startup: program the board with various hardware parameters
   *
   * This function takes board-specific information, like clock frequencies
   * and serial data formats, and passes that information to the codec and
   * transport drivers.
   */
  static int p1022_ds_startup(struct snd_pcm_substream *substream)
  {
  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
  	struct machine_data *mdata =
  		container_of(rtd->card, struct machine_data, card);
  	struct device *dev = rtd->card->dev;
  	int ret = 0;
  
  	/* Tell the codec driver what the serial protocol is. */
  	ret = snd_soc_dai_set_fmt(rtd->codec_dai, mdata->dai_format);
  	if (ret < 0) {
  		dev_err(dev, "could not set codec driver audio format\n");
  		return ret;
  	}
  
  	/*
  	 * Tell the codec driver what the MCLK frequency is, and whether it's
  	 * a slave or master.
  	 */
  	ret = snd_soc_dai_set_sysclk(rtd->codec_dai, 0, mdata->clk_frequency,
  				     mdata->codec_clk_direction);
  	if (ret < 0) {
  		dev_err(dev, "could not set codec driver clock params\n");
  		return ret;
  	}
  
  	return 0;
  }
  
  /**
   * p1022_ds_machine_remove: Remove the sound device
   *
   * This function is called to remove the sound device for one SSI.  We
   * de-program the DMACR and PMUXCR register.
   */
  static int p1022_ds_machine_remove(struct snd_soc_card *card)
  {
  	struct machine_data *mdata =
  		container_of(card, struct machine_data, card);
  	struct ccsr_guts_85xx __iomem *guts;
  
  	guts = ioremap(guts_phys, sizeof(struct ccsr_guts_85xx));
  	if (!guts) {
  		dev_err(card->dev, "could not map global utilities\n");
  		return -ENOMEM;
  	}
  
  	/* Restore the signal routing */
  	clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_UART0_I2C1_MASK);
  	clrbits32(&guts->pmuxcr, CCSR_GUTS_PMUXCR_SSI_DMA_TDM_MASK);
  	guts_set_dmuxcr(guts, mdata->dma_id[0], mdata->dma_channel_id[0], 0);
  	guts_set_dmuxcr(guts, mdata->dma_id[1], mdata->dma_channel_id[1], 0);
  
  	iounmap(guts);
  
  	return 0;
  }
  
  /**
   * p1022_ds_ops: ASoC machine driver operations
   */
  static struct snd_soc_ops p1022_ds_ops = {
  	.startup = p1022_ds_startup,
  };
  
  /**
   * get_node_by_phandle_name - get a node by its phandle name
   *
   * This function takes a node, the name of a property in that node, and a
   * compatible string.  Assuming the property is a phandle to another node,
   * it returns that node, (optionally) if that node is compatible.
   *
   * If the property is not a phandle, or the node it points to is not compatible
   * with the specific string, then NULL is returned.
   */
  static struct device_node *get_node_by_phandle_name(struct device_node *np,
  	const char *name, const char *compatible)
  {
  	np = of_parse_phandle(np, name, 0);
  	if (!np)
  		return NULL;
  
  	if (!of_device_is_compatible(np, compatible)) {
  		of_node_put(np);
  		return NULL;
  	}
  
  	return np;
  }
  
  /**
   * get_parent_cell_index -- return the cell-index of the parent of a node
   *
   * Return the value of the cell-index property of the parent of the given
   * node.  This is used for DMA channel nodes that need to know the DMA ID
   * of the controller they are on.
   */
  static int get_parent_cell_index(struct device_node *np)
  {
  	struct device_node *parent = of_get_parent(np);
  	const u32 *iprop;
  	int ret = -1;
  
  	if (!parent)
  		return -1;
  
  	iprop = of_get_property(parent, "cell-index", NULL);
  	if (iprop)
  		ret = *iprop;
  
  	of_node_put(parent);
  
  	return ret;
  }
  
  /**
   * codec_node_dev_name - determine the dev_name for a codec node
   *
   * This function determines the dev_name for an I2C node.  This is the name
   * that would be returned by dev_name() if this device_node were part of a
   * 'struct device'  It's ugly and hackish, but it works.
   *
   * The dev_name for such devices include the bus number and I2C address. For
   * example, "cs4270-codec.0-004f".
   */
  static int codec_node_dev_name(struct device_node *np, char *buf, size_t len)
  {
  	const u32 *iprop;
  	int bus, addr;
  	char temp[DAI_NAME_SIZE];
  
  	of_modalias_node(np, temp, DAI_NAME_SIZE);
  
  	iprop = of_get_property(np, "reg", NULL);
  	if (!iprop)
  		return -EINVAL;
  
  	addr = *iprop;
  
  	bus = get_parent_cell_index(np);
  	if (bus < 0)
  		return bus;
  
  	snprintf(buf, len, "%s-codec.%u-%04x", temp, bus, addr);
  
  	return 0;
  }
  
  static int get_dma_channel(struct device_node *ssi_np,
  			   const char *compatible,
  			   struct snd_soc_dai_link *dai,
  			   unsigned int *dma_channel_id,
  			   unsigned int *dma_id)
  {
  	struct resource res;
  	struct device_node *dma_channel_np;
  	const u32 *iprop;
  	int ret;
  
  	dma_channel_np = get_node_by_phandle_name(ssi_np, compatible,
  						  "fsl,ssi-dma-channel");
  	if (!dma_channel_np)
  		return -EINVAL;
  
  	/* Determine the dev_name for the device_node.  This code mimics the
  	 * behavior of of_device_make_bus_id(). We need this because ASoC uses
  	 * the dev_name() of the device to match the platform (DMA) device with
  	 * the CPU (SSI) device.  It's all ugly and hackish, but it works (for
  	 * now).
  	 *
  	 * dai->platform name should already point to an allocated buffer.
  	 */
  	ret = of_address_to_resource(dma_channel_np, 0, &res);
  	if (ret)
  		return ret;
  	snprintf((char *)dai->platform_name, DAI_NAME_SIZE, "%llx.%s",
  		 (unsigned long long) res.start, dma_channel_np->name);
  
  	iprop = of_get_property(dma_channel_np, "cell-index", NULL);
  	if (!iprop) {
  		of_node_put(dma_channel_np);
  		return -EINVAL;
  	}
  
  	*dma_channel_id = *iprop;
  	*dma_id = get_parent_cell_index(dma_channel_np);
  	of_node_put(dma_channel_np);
  
  	return 0;
  }
  
  /**
   * p1022_ds_probe: platform probe function for the machine driver
   *
   * Although this is a machine driver, the SSI node is the "master" node with
   * respect to audio hardware connections.  Therefore, we create a new ASoC
   * device for each new SSI node that has a codec attached.
   */
  static int p1022_ds_probe(struct platform_device *pdev)
  {
  	struct device *dev = pdev->dev.parent;
  	/* ssi_pdev is the platform device for the SSI node that probed us */
  	struct platform_device *ssi_pdev =
  		container_of(dev, struct platform_device, dev);
  	struct device_node *np = ssi_pdev->dev.of_node;
  	struct device_node *codec_np = NULL;
  	struct platform_device *sound_device = NULL;
  	struct machine_data *mdata;
  	int ret = -ENODEV;
  	const char *sprop;
  	const u32 *iprop;
  
  	/* Find the codec node for this SSI. */
  	codec_np = of_parse_phandle(np, "codec-handle", 0);
  	if (!codec_np) {
  		dev_err(dev, "could not find codec node\n");
  		return -EINVAL;
  	}
  
  	mdata = kzalloc(sizeof(struct machine_data), GFP_KERNEL);
  	if (!mdata) {
  		ret = -ENOMEM;
  		goto error_put;
  	}
  
  	mdata->dai[0].cpu_dai_name = dev_name(&ssi_pdev->dev);
  	mdata->dai[0].ops = &p1022_ds_ops;
  
  	/* Determine the codec name, it will be used as the codec DAI name */
  	ret = codec_node_dev_name(codec_np, mdata->codec_name, DAI_NAME_SIZE);
  	if (ret) {
  		dev_err(&pdev->dev, "invalid codec node %s\n",
  			codec_np->full_name);
  		ret = -EINVAL;
  		goto error;
  	}
  	mdata->dai[0].codec_name = mdata->codec_name;
  
  	/* We register two DAIs per SSI, one for playback and the other for
  	 * capture.  We support codecs that have separate DAIs for both playback
  	 * and capture.
  	 */
  	memcpy(&mdata->dai[1], &mdata->dai[0], sizeof(struct snd_soc_dai_link));
  
  	/* The DAI names from the codec (snd_soc_dai_driver.name) */
  	mdata->dai[0].codec_dai_name = "wm8776-hifi-playback";
  	mdata->dai[1].codec_dai_name = "wm8776-hifi-capture";
  
  	/* Get the device ID */
  	iprop = of_get_property(np, "cell-index", NULL);
  	if (!iprop) {
  		dev_err(&pdev->dev, "cell-index property not found\n");
  		ret = -EINVAL;
  		goto error;
  	}
  	mdata->ssi_id = *iprop;
  
  	/* Get the serial format and clock direction. */
  	sprop = of_get_property(np, "fsl,mode", NULL);
  	if (!sprop) {
  		dev_err(&pdev->dev, "fsl,mode property not found\n");
  		ret = -EINVAL;
  		goto error;
  	}
  
  	if (strcasecmp(sprop, "i2s-slave") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_I2S;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
  
  		/* In i2s-slave mode, the codec has its own clock source, so we
  		 * need to get the frequency from the device tree and pass it to
  		 * the codec driver.
  		 */
  		iprop = of_get_property(codec_np, "clock-frequency", NULL);
  		if (!iprop || !*iprop) {
  			dev_err(&pdev->dev, "codec bus-frequency "
  				"property is missing or invalid\n");
  			ret = -EINVAL;
  			goto error;
  		}
  		mdata->clk_frequency = *iprop;
  	} else if (strcasecmp(sprop, "i2s-master") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_I2S;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
  	} else if (strcasecmp(sprop, "lj-slave") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
  	} else if (strcasecmp(sprop, "lj-master") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_LEFT_J;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
  	} else if (strcasecmp(sprop, "rj-slave") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
  	} else if (strcasecmp(sprop, "rj-master") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_RIGHT_J;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
  	} else if (strcasecmp(sprop, "ac97-slave") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_AC97;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_OUT;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_IN;
  	} else if (strcasecmp(sprop, "ac97-master") == 0) {
  		mdata->dai_format = SND_SOC_DAIFMT_AC97;
  		mdata->codec_clk_direction = SND_SOC_CLOCK_IN;
  		mdata->cpu_clk_direction = SND_SOC_CLOCK_OUT;
  	} else {
  		dev_err(&pdev->dev,
  			"unrecognized fsl,mode property '%s'\n", sprop);
  		ret = -EINVAL;
  		goto error;
  	}
  
  	if (!mdata->clk_frequency) {
  		dev_err(&pdev->dev, "unknown clock frequency\n");
  		ret = -EINVAL;
  		goto error;
  	}
  
  	/* Find the playback DMA channel to use. */
  	mdata->dai[0].platform_name = mdata->platform_name[0];
  	ret = get_dma_channel(np, "fsl,playback-dma", &mdata->dai[0],
  			      &mdata->dma_channel_id[0],
  			      &mdata->dma_id[0]);
  	if (ret) {
  		dev_err(&pdev->dev, "missing/invalid playback DMA phandle\n");
  		goto error;
  	}
  
  	/* Find the capture DMA channel to use. */
  	mdata->dai[1].platform_name = mdata->platform_name[1];
  	ret = get_dma_channel(np, "fsl,capture-dma", &mdata->dai[1],
  			      &mdata->dma_channel_id[1],
  			      &mdata->dma_id[1]);
  	if (ret) {
  		dev_err(&pdev->dev, "missing/invalid capture DMA phandle\n");
  		goto error;
  	}
  
  	/* Initialize our DAI data structure.  */
  	mdata->dai[0].stream_name = "playback";
  	mdata->dai[1].stream_name = "capture";
  	mdata->dai[0].name = mdata->dai[0].stream_name;
  	mdata->dai[1].name = mdata->dai[1].stream_name;
  
  	mdata->card.probe = p1022_ds_machine_probe;
  	mdata->card.remove = p1022_ds_machine_remove;
  	mdata->card.name = pdev->name; /* The platform driver name */
  	mdata->card.num_links = 2;
  	mdata->card.dai_link = mdata->dai;
  
  	/* Allocate a new audio platform device structure */
  	sound_device = platform_device_alloc("soc-audio", -1);
  	if (!sound_device) {
  		dev_err(&pdev->dev, "platform device alloc failed\n");
  		ret = -ENOMEM;
  		goto error;
  	}
  
  	/* Associate the card data with the sound device */
  	platform_set_drvdata(sound_device, &mdata->card);
  
  	/* Register with ASoC */
  	ret = platform_device_add(sound_device);
  	if (ret) {
  		dev_err(&pdev->dev, "platform device add failed\n");
  		goto error;
  	}
  	dev_set_drvdata(&pdev->dev, sound_device);
  
  	of_node_put(codec_np);
  
  	return 0;
  
  error:
  	if (sound_device)
  		platform_device_unregister(sound_device);
  
  	kfree(mdata);
  error_put:
  	of_node_put(codec_np);
  	return ret;
  }
  
  /**
   * p1022_ds_remove: remove the platform device
   *
   * This function is called when the platform device is removed.
   */
  static int __devexit p1022_ds_remove(struct platform_device *pdev)
  {
  	struct platform_device *sound_device = dev_get_drvdata(&pdev->dev);
  	struct snd_soc_card *card = platform_get_drvdata(sound_device);
  	struct machine_data *mdata =
  		container_of(card, struct machine_data, card);
  
  	platform_device_unregister(sound_device);
  
  	kfree(mdata);
  	sound_device->dev.platform_data = NULL;
  
  	dev_set_drvdata(&pdev->dev, NULL);
  
  	return 0;
  }
  
  static struct platform_driver p1022_ds_driver = {
  	.probe = p1022_ds_probe,
  	.remove = __devexit_p(p1022_ds_remove),
  	.driver = {
  		/* The name must match the 'model' property in the device tree,
  		 * in lowercase letters, but only the part after that last
  		 * comma.  This is because some model properties have a "fsl,"
  		 * prefix.
  		 */
  		.name = "snd-soc-p1022",
  		.owner = THIS_MODULE,
  	},
  };
  
  /**
   * p1022_ds_init: machine driver initialization.
   *
   * This function is called when this module is loaded.
   */
  static int __init p1022_ds_init(void)
  {
  	struct device_node *guts_np;
  	struct resource res;
  
  	pr_info("Freescale P1022 DS ALSA SoC machine driver\n");
  
  	/* Get the physical address of the global utilities registers */
  	guts_np = of_find_compatible_node(NULL, NULL, "fsl,p1022-guts");
  	if (of_address_to_resource(guts_np, 0, &res)) {
  		pr_err("p1022-ds: missing/invalid global utilities node\n");
  		return -EINVAL;
  	}
  	guts_phys = res.start;
  	of_node_put(guts_np);
  
  	return platform_driver_register(&p1022_ds_driver);
  }
  
  /**
   * p1022_ds_exit: machine driver exit
   *
   * This function is called when this driver is unloaded.
   */
  static void __exit p1022_ds_exit(void)
  {
  	platform_driver_unregister(&p1022_ds_driver);
  }
  
  module_init(p1022_ds_init);
  module_exit(p1022_ds_exit);
  
  MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
  MODULE_DESCRIPTION("Freescale P1022 DS ALSA SoC machine driver");
  MODULE_LICENSE("GPL v2");
  