Re: [alsa-devel] [PATCH 2/3] ALSA SoC: Add mpc5200-psc I2S driver

On Tue, 2008-07-01 at 17:53 -0600, Grant Likely wrote:

From: Grant Likely grant.likely@secretlab.ca

This is an I2S bus driver for the MPC5200 PSC device. It is probably will not be merged as-is because it uses v1 of the ASoC API, but I want to get it out there for comments.

Looks good, just minor comments.

---

sound/soc/fsl/Kconfig | 6 sound/soc/fsl/Makefile | 2 sound/soc/fsl/mpc5200_psc_i2s.c | 899 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 907 insertions(+), 0 deletions(-)

diff --git a/sound/soc/fsl/Kconfig b/sound/soc/fsl/Kconfig index 257101f..5daa8d3 100644 --- a/sound/soc/fsl/Kconfig +++ b/sound/soc/fsl/Kconfig @@ -17,4 +17,10 @@ config SND_SOC_MPC8610_HPCD help Say Y if you want to enable audio on the Freescale MPC8610 HPCD.

+config SND_SOC_MPC5200_I2S

• bool "Freescale MPC5200 PSC in I2S mode driver"

Is this built-in only ?

• depends on SND_SOC && PPC_MPC52xx
• help

•  Say Y here to support the MPC5200 PSCs in I2S mode.
  

endmenu diff --git a/sound/soc/fsl/Makefile b/sound/soc/fsl/Makefile index 62f680a..98729a1 100644 --- a/sound/soc/fsl/Makefile +++ b/sound/soc/fsl/Makefile @@ -4,3 +4,5 @@ obj-$(CONFIG_SND_SOC_MPC8610_HPCD) += mpc8610_hpcd.o # MPC8610 Platform Support obj-$(CONFIG_SND_SOC_MPC8610) += fsl_ssi.o fsl_dma.o

+obj-$(CONFIG_SND_SOC_MPC5200_I2S) += mpc5200_psc_i2s.o

diff --git a/sound/soc/fsl/mpc5200_psc_i2s.c b/sound/soc/fsl/mpc5200_psc_i2s.c new file mode 100644 index 0000000..81d0933 --- /dev/null +++ b/sound/soc/fsl/mpc5200_psc_i2s.c @@ -0,0 +1,899 @@ +/*

• • Freescale MPC5200 PSC in I2S mode
• • ALSA SoC Digital Audio Interface (DAI) driver
• • Copyright (C) 2008 Secret Lab Technologies Ltd.
• */

+#include <linux/init.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/delay.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/dma-mapping.h>

+#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/initval.h> +#include <sound/soc.h> +#include <sound/soc-of.h>

+#include <sysdev/bestcomm/bestcomm.h> +#include <sysdev/bestcomm/gen_bd.h> +#include <asm/mpc52xx_psc.h>

+MODULE_AUTHOR("Grant Likely grant.likely@secretlab.ca"); +MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver"); +MODULE_LICENSE("GPL");

+/**

• • PSC_I2S_RATES: sample rates supported by the I2S
• • This driver currently only supports the PSC running in I2S slave mode,
• • which means the codec determines the sample rate. Therefore, we tell
• • ALSA that we support all rates and let the codec driver decide what rates
• • are really supported.
• */

+#define PSC_I2S_RATES (SNDRV_PCM_RATE_5512 | SNDRV_PCM_RATE_8000_192000 | \

• 	SNDRV_PCM_RATE_CONTINUOUS)
  

+/**

• • PSC_I2S_FORMATS: audio formats supported by the PSC I2S mode
• */

+#define PSC_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \

• 	 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S24_BE | \
  

• 	 SNDRV_PCM_FMTBIT_S32_BE)
  

+/**

• • psc_i2s_stream - Data specific to a single stream (playback or capture)
• • @active: flag indicating if the stream is active
• • @psc_i2s: pointer back to parent psc_i2s data structure
• • @bcom_task: bestcomm task structure
• • @irq: irq number for bestcomm task
• • @period_start: physical address of start of DMA region
• • @period_end: physical address of end of DMA region
• • @period_next_pt: physical address of next DMA buffer to enqueue
• • @period_bytes: size of DMA period in bytes
• */

+struct psc_i2s_stream {

• int active;
• struct psc_i2s *psc_i2s;
• struct bcom_task *bcom_task;
• int irq;
• struct snd_pcm_substream *stream;
• dma_addr_t period_start;
• dma_addr_t period_end;
• dma_addr_t period_next_pt;
• dma_addr_t period_current_pt;
• int period_bytes;

+};

+/**

• • psc_i2s - Private driver data
• • @name: short name for this device ("PSC0", "PSC1", etc)
• • @psc_regs: pointer to the PSC's registers
• • @fifo_regs: pointer to the PSC's FIFO registers
• • @irq: IRQ of this PSC
• • @dev: struct device pointer
• • @playback: the number of playback streams opened
• • @capture: the number of capture streams opened
• • @dai: the CPU DAI for this device
• • @playback_stream: Playback stream context data
• • @capture_stream: Capture stream context data
• */

+struct psc_i2s {

• char name[32];
• struct mpc52xx_psc __iomem *psc_regs;
• struct mpc52xx_psc_fifo __iomem *fifo_regs;
• unsigned int irq;
• struct device *dev;
• struct snd_soc_cpu_dai dai;
• spinlock_t lock;
• /* per-stream data */
• struct psc_i2s_stream playback_stream;
• struct psc_i2s_stream capture_stream;
• /* Statistics */
• struct {

• int overrun_count;
  

• int underrun_count;
  

• } stats;

+};

+/*

• • Interrupt handlers
• */

+static irqreturn_t psc_i2s_status_irq(int irq, void *_psc_i2s) +{

• struct psc_i2s *psc_i2s = _psc_i2s;
• struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
• u16 imr;
• u16 isr;
• isr = in_be16(&regs->mpc52xx_psc_isr);
• imr = in_be16(&regs->mpc52xx_psc_imr);
• /* Playback underrun error */
• if (isr & imr & MPC52xx_PSC_IMR_TXEMP)

• psc_i2s->stats.underrun_count++;
  

• /* Capture overrun error */
• if (isr & imr & MPC52xx_PSC_IMR_ORERR)

• psc_i2s->stats.overrun_count++;
  

• out_8(&regs->command, 4 << 4); /* reset the error status */
• return IRQ_HANDLED;

+}

+/**

• • psc_i2s_bcom_enqueue_next_buffer - Enqueue another audio buffer
• • @s: pointer to stream private data structure
• • Enqueues another audio period buffer into the bestcomm queue.
• • Note: The routine must only be called when there is space available in
• • the queue. Otherwise the enqueue will fail and the audio ring buffer
• • will get out of sync
• */

+static void psc_i2s_bcom_enqueue_next_buffer(struct psc_i2s_stream *s) +{

• struct bcom_bd *bd;
• /* Prepare and enqueue the next buffer descriptor */
• bd = bcom_prepare_next_buffer(s->bcom_task);
• bd->status = s->period_bytes;
• bd->data[0] = s->period_next_pt;
• bcom_submit_next_buffer(s->bcom_task, NULL);
• /* Update for next period */
• s->period_next_pt += s->period_bytes;
• if (s->period_next_pt >= s->period_end)

• s->period_next_pt = s->period_start;
  

+}

+/* Bestcomm DMA irq handler */ +static irqreturn_t psc_i2s_bcom_irq(int irq, void *_psc_i2s_stream) +{

• struct psc_i2s_stream *s = _psc_i2s_stream;
• //spin_lock(&s->psc_i2s->lock);
• /* For each finished period, dequeue the completed period buffer

• * and enqueue a new one in it's place. */
  

• while (bcom_buffer_done(s->bcom_task)) {

• bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
  

• s->period_current_pt += s->period_bytes;
  

• if (s->period_current_pt >= s->period_end)
  

• 	s->period_current_pt = s->period_start;
  

• psc_i2s_bcom_enqueue_next_buffer(s);
  

• bcom_enable(s->bcom_task);
  

• }
• //spin_unlock(&s->psc_i2s->lock);
• /* If the stream is active, then also inform the PCM middle layer

• * of the period finished event. */
  

• if (s->active)

• snd_pcm_period_elapsed(s->stream);
  

• return IRQ_HANDLED;

+}

+/**

• • psc_i2s_startup: create a new substream
• • This is the first function called when a stream is opened.
• • If this is the first stream open, then grab the IRQ and program most of
• • the PSC registers.
• */

+static int psc_i2s_startup(struct snd_pcm_substream *substream) +{

• int playback_irq, capture_irq, rc;
• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
• struct mpc52xx_psc_fifo __iomem *fiforegs = psc_i2s->fifo_regs;
• dev_dbg(psc_i2s->dev, "psc_i2s_startup(substream=%p)\n", substream);
• /* Disable all interrupts and reset the PSC */
• out_be16(&regs->mpc52xx_psc_imr, 0);
• out_8(&regs->command, 3 << 4); /* reset transmitter */
• out_8(&regs->command, 2 << 4); /* reset receiver */
• out_8(&regs->command, 1 << 4); /* reset mode */
• out_8(&regs->command, 4 << 4); /* reset error */
• /* Default to CODEC8 mode */
• out_be32(&regs->sicr,

•  MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
  

•  MPC52xx_PSC_SICR_CLKPOL | MPC52xx_PSC_SICR_SIM_CODEC_8);
  

• /* First write: RxRdy (FIFO Alarm) generates receive FIFO interrupt */
• /* Second write to mode: register Normal mode for non loopback */
• out_8(&regs->mode, 0);
• out_8(&regs->mode, 0);
• /* Set the TX and RX fifo alarm thresholds */
• out_be16(&fiforegs->rfalarm, 0x100); /* set RFALARM level */
• out_8(&fiforegs->rfcntl, 0x4); /* set RFGRAN level (bytes) */
• out_be16(&fiforegs->tfalarm, 0x100); /* set TFALARM level */
• out_8(&fiforegs->tfcntl, 0x7); /* set TFGRAN level (bytes*4) */
• /* Setup the IRQs */
• playback_irq = bcom_get_task_irq(psc_i2s->playback_stream.bcom_task);
• capture_irq = bcom_get_task_irq(psc_i2s->capture_stream.bcom_task);
• rc = request_irq(psc_i2s->irq, &psc_i2s_status_irq, IRQF_SHARED,

• 	 "psc-i2s-status", psc_i2s);
  

• rc |= request_irq(capture_irq, &psc_i2s_bcom_irq, IRQF_SHARED,

• 	  "psc-i2s-capture", &psc_i2s->capture_stream);
  

• rc |= request_irq(playback_irq, &psc_i2s_bcom_irq, IRQF_SHARED,

• 	  "psc-i2s-playback", &psc_i2s->playback_stream);
  

• if (rc) {

• free_irq(psc_i2s->irq, psc_i2s);
  

• free_irq(capture_irq, &psc_i2s->capture_stream);
  

• free_irq(playback_irq, &psc_i2s->playback_stream);
  

• return -ENODEV;
  

• }
• return 0;

+}

+static int psc_i2s_hw_params(struct snd_pcm_substream *substream,

• 		 struct snd_pcm_hw_params *params)
  

+{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• u32 sicr;
• dev_dbg(psc_i2s->dev, "%s(substream=%p) p_size=%i p_bytes=%i"

• " periods=%i buffer_size=%i  buffer_bytes=%i\n",
  

• __FUNCTION__, substream, params_period_size(params),
  

• params_period_bytes(params), params_periods(params),
  

• params_buffer_size(params), params_buffer_bytes(params));
  

• sicr = MPC52xx_PSC_SICR_DTS1 |

•       MPC52xx_PSC_SICR_I2S | MPC52xx_PSC_SICR_CLKPOL;
  

• switch (params_format(params)) {

• case SNDRV_PCM_FORMAT_S8:
  

• sicr |= MPC52xx_PSC_SICR_SIM_CODEC_8;
  

• break;
  

• case SNDRV_PCM_FORMAT_S16_BE:
  

• sicr |= MPC52xx_PSC_SICR_SIM_CODEC_16;
  

• break;
  

• case SNDRV_PCM_FORMAT_S24_BE:
  

• sicr |= MPC52xx_PSC_SICR_SIM_CODEC_24;
  

• break;
  

• case SNDRV_PCM_FORMAT_S32_BE:
  

• sicr |= MPC52xx_PSC_SICR_SIM_CODEC_32;
  

• break;
  

• default:
  

• dev_dbg(psc_i2s->dev, "invalid format\n");
  

• return -EINVAL;
  

• }

case should have the same indent level as switch.

• out_be32(&psc_i2s->psc_regs->sicr, sicr);
• //rc = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
• //if (rc) {
• // dev_err(psc_i2s->dev, "could not allocate dma buffer\n");
• // return rc;
• //}
• snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
• return 0;

+}

+static int psc_i2s_hw_free(struct snd_pcm_substream *substream) +{

• //return snd_pcm_lib_free_pages(substream);
• snd_pcm_set_runtime_buffer(substream, NULL);
• return 0;

+}

+/**

• • psc_i2s_trigger: start and stop the DMA transfer.
• • This function is called by ALSA to start, stop, pause, and resume the DMA
• • transfer of data.
• */

+static int psc_i2s_trigger(struct snd_pcm_substream *substream, int cmd) +{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• struct snd_pcm_runtime *runtime = substream->runtime;
• struct psc_i2s_stream *s;
• struct mpc52xx_psc __iomem *regs = psc_i2s->psc_regs;
• u16 imr;
• u8 psc_cmd;
• long flags;
• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)

• s = &psc_i2s->capture_stream;
  

• else

• s = &psc_i2s->playback_stream;
  

• dev_dbg(psc_i2s->dev, "psc_i2s_trigger(substream=%p, cmd=%i)"

• " stream_id=%i\n",
  

• substream, cmd, substream->pstr->stream);
  

• switch (cmd) {

• case SNDRV_PCM_TRIGGER_START:
  

ditto re case indent.

• s->period_bytes = frames_to_bytes(runtime,
  

• 				  runtime->period_size);
  

• s->period_start = virt_to_phys(runtime->dma_area);
  

• s->period_end = s->period_start +
  

• 		(s->period_bytes * runtime->periods);
  

• s->period_next_pt = s->period_start;
  

• s->period_current_pt = s->period_start;
  

• s->active = 1;
  

• /* First; reset everything */
  

• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
  

• 	out_8(&regs->command, MPC52xx_PSC_RST_RX);
  

• 	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
  

• } else {
  

• 	out_8(&regs->command, MPC52xx_PSC_RST_TX);
  

• 	out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
  

• }
  

• /* Next, fill up the bestcomm bd queue and enable DMA.
  

•  * This will begin filling the PSC's fifo. */
  

• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
  

• 	bcom_gen_bd_rx_reset(s->bcom_task);
  

• else
  

• 	bcom_gen_bd_tx_reset(s->bcom_task);
  

• while (!bcom_queue_full(s->bcom_task))
  

• 	psc_i2s_bcom_enqueue_next_buffer(s);
  

• bcom_enable(s->bcom_task);
  

• /* Update interrupt enable settings.  This must be done
  

•  * before the PSC is enabled so that TX underrun events
  

•  * are not missed. */
  

• imr = 0;
  

• if (psc_i2s->playback_stream.active)
  

• 	imr |= MPC52xx_PSC_IMR_TXEMP;
  

• if (psc_i2s->capture_stream.active)
  

• 	imr |= MPC52xx_PSC_IMR_ORERR;
  

• out_be16(&regs->isr_imr.imr, imr);
  

• /* Due to errata in the i2s mode; need to line up enabling
  

•  * the transmitter with a transition on the frame sync
  

•  * line */
  

• spin_lock_irqsave(&psc_i2s->lock, flags);
  

• /* first make sure it is low */
  

• while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) != 0);
  

• /* then wait for the transition to high */
  

• while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) == 0);
  

We should be able to exit both while loops if the conditions are not met within a certain time limit.

• /* Finally, enable the PSC.
  

•  * Receiver must always be enabled; even when we only want
  

•  * transmit.  (see 15.3.2.3 of MPC5200B User's Guide) */
  

• psc_cmd = MPC52xx_PSC_RX_ENABLE;
  

• if (substream->pstr->stream == SNDRV_PCM_STREAM_PLAYBACK)
  

• 	psc_cmd |= MPC52xx_PSC_TX_ENABLE;
  

• out_8(&regs->command, psc_cmd);
  

• spin_unlock_irqrestore(&psc_i2s->lock, flags);
  

• break;
  

• case SNDRV_PCM_TRIGGER_STOP:
  

• /* Turn off the PSC */
  

• s->active = 0;
  

• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
  

• 	if (!psc_i2s->playback_stream.active) {
  

• 		out_8(&regs->command, 2 << 4);	/* reset rx */
  

• 		out_8(&regs->command, 3 << 4);	/* reset tx */
  

• 		out_8(&regs->command, 4 << 4);	/* reset err */
  

• 	}
  

• } else {
  

• 	out_8(&regs->command, 3 << 4);	/* reset tx */
  

• 	out_8(&regs->command, 4 << 4);	/* reset err */
  

• 	if (!psc_i2s->capture_stream.active)
  

• 		out_8(&regs->command, 2 << 4);	/* reset rx */
  

• }
  

• bcom_disable(s->bcom_task);
  

• while (!bcom_queue_empty(s->bcom_task))
  

• 	bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
  

• break;
  

• default:
  

• dev_dbg(psc_i2s->dev, "invalid command\n");
  

• return -EINVAL;
  

• }
• /* Update interrupt enable settings */
• imr = 0;
• if (psc_i2s->playback_stream.active) imr |= MPC52xx_PSC_IMR_TXEMP;
• if (psc_i2s->capture_stream.active) imr |= MPC52xx_PSC_IMR_ORERR;
• out_be16(&regs->isr_imr.imr, imr);
• return 0;

+}

+/**

• • psc_i2s_shutdown: shutdown the data transfer on a stream
• • Shutdown the PSC if there are no other substreams open.
• */

+static void psc_i2s_shutdown(struct snd_pcm_substream *substream) +{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• dev_dbg(psc_i2s->dev, "psc_i2s_shutdown(substream=%p)\n", substream);
• /*

• * If this is the last active substream, disable the PSC and release
  

• * the IRQ.
  

• */
  

• if (!psc_i2s->playback_stream.active &&

•    !psc_i2s->capture_stream.active) {
  

• /* TODO: shut off channels */
  

• free_irq(psc_i2s->irq, psc_i2s);
  

• free_irq(bcom_get_task_irq(psc_i2s->capture_stream.bcom_task),
  

• 	 &psc_i2s->capture_stream);
  

• free_irq(bcom_get_task_irq(psc_i2s->playback_stream.bcom_task),
  

• 	 &psc_i2s->playback_stream);
  

• }

+}

+/**

• • psc_i2s_set_sysclk: set the clock frequency and direction
• • This function is called by the machine driver to tell us what the clock
• • frequency and direction are.
• • Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
• • and we don't care about the frequency. Return an error if the direction
• • is not SND_SOC_CLOCK_IN.
• • @clk_id: reserved, should be zero
• • @freq: the frequency of the given clock ID, currently ignored
• • @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
• */

+static int psc_i2s_set_sysclk(struct snd_soc_cpu_dai *cpu_dai,

• 	      int clk_id, unsigned int freq, int dir)
  

+{

• struct psc_i2s *psc_i2s = cpu_dai->private_data;
• dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",

• 		cpu_dai, dir);
  

• return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;

+}

+/**

• • psc_i2s_set_fmt: set the serial format.
• • This function is called by the machine driver to tell us what serial
• • format to use.
• • This driver only supports I2S mode. Return an error if the format is
• • not SND_SOC_DAIFMT_I2S.
• • @format: one of SND_SOC_DAIFMT_xxx
• */

+static int psc_i2s_set_fmt(struct snd_soc_cpu_dai *cpu_dai, unsigned int format) +{

• struct psc_i2s *psc_i2s = cpu_dai->private_data;
• dev_dbg(psc_i2s->dev, "psc_i2s_set_fmt(cpu_dai=%p, format=%i)\n",

• 		cpu_dai, format);
  

• return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;

+}

+/* ---------------------------------------------------------------------

• • ALSA SoC Bindings
• • • Digital Audio Interface (DAI) template
• • • create/destroy dai hooks
• */

+/**

• • psc_i2s_dai_template: template CPU Digital Audio Interface
• */

+static struct snd_soc_cpu_dai psc_i2s_dai_template = {

• .type = SND_SOC_DAI_I2S,
• .playback = {

• .channels_min = 2,
  

• .channels_max = 2,
  

• .rates = PSC_I2S_RATES,
  

• .formats = PSC_I2S_FORMATS,
  

• },
• .capture = {

• .channels_min = 2,
  

• .channels_max = 2,
  

• .rates = PSC_I2S_RATES,
  

• .formats = PSC_I2S_FORMATS,
  

• },
• .ops = {

• .startup = psc_i2s_startup,
  

• .hw_params = psc_i2s_hw_params,
  

• .hw_free = psc_i2s_hw_free,
  

• .shutdown = psc_i2s_shutdown,
  

• .trigger = psc_i2s_trigger,
  

• },
• .dai_ops = {

• .set_sysclk = psc_i2s_set_sysclk,
  

• .set_fmt = psc_i2s_set_fmt,
  

• },

+};

+/* ---------------------------------------------------------------------

• • The PSC I2S 'ASoC platform' driver
• • Can be referenced by an 'ASoC machine' driver
• • This driver only deals with the audio bus; it doesn't have any
• • interaction with the attached codec
• */

+static const struct snd_pcm_hardware psc_i2s_pcm_hardware = {

• .info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |

• SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER,
  

• .formats = SNDRV_PCM_FMTBIT_S8 |SNDRV_PCM_FMTBIT_S16_BE |

•    SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
  

• .rate_min = 8000,
• .rate_max = 48000,
• .channels_min = 2,
• .channels_max = 2,
• .period_bytes_max = 1024 * 1024,
• .period_bytes_min = 32,
• .period_bytes_max = 1024 * 1024,
• .periods_min = 2,
• .periods_max = 256,
• .buffer_bytes_max = 2 * 1024 * 1024,
• .fifo_size = 0,

+};

Fwiw, I usually separate out the DMA from I2S so it can be used by AC97, PCM interfaces etc. If your hardware only has I2S the it's not required.

+static unsigned int psc_i2s_fixed_rates[] = {

• 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000,

+};

+static struct snd_pcm_hw_constraint_list psc_i2s_constraints_rates = {

• .count = ARRAY_SIZE(psc_i2s_fixed_rates),
• .list = psc_i2s_fixed_rates,
• .mask = 0,

+};

+static int psc_i2s_pcm_open(struct snd_pcm_substream *substream) +{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• struct psc_i2s_stream *s;
• int rc;
• dev_dbg(psc_i2s->dev, "psc_i2s_pcm_open(substream=%p)\n", substream);
• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)

• s = &psc_i2s->capture_stream;
  

• else

• s = &psc_i2s->playback_stream;
  

• snd_soc_set_runtime_hwparams(substream, &psc_i2s_pcm_hardware);
• rc = snd_pcm_hw_constraint_integer(substream->runtime,

• 			   SNDRV_PCM_HW_PARAM_PERIODS);
  

• if (rc < 0) {

• dev_err(psc_i2s->dev, "invalid buffer size\n");
  

• return rc;
  

• }
• rc = snd_pcm_hw_constraint_list(substream->runtime, 0,

• 			SNDRV_PCM_HW_PARAM_RATE,
  

• 			&psc_i2s_constraints_rates);
  

• if (rc < 0) {

• dev_err(psc_i2s->dev, "invalid rate\n");
  

• return rc;
  

• }
• s->stream = substream;
• return 0;

+}

+static int psc_i2s_pcm_close(struct snd_pcm_substream * substream) +{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• struct psc_i2s_stream *s;
• dev_dbg(psc_i2s->dev, "psc_i2s_pcm_close(substream=%p)\n", substream);
• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)

• s = &psc_i2s->capture_stream;
  

• else

• s = &psc_i2s->playback_stream;
  

• s->stream = NULL;
• return 0;

+}

+static snd_pcm_uframes_t +psc_i2s_pcm_pointer(struct snd_pcm_substream *substream) +{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
• struct psc_i2s_stream *s;
• dma_addr_t count;
• if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)

• s = &psc_i2s->capture_stream;
  

• else

• s = &psc_i2s->playback_stream;
  

• /*FIXME: count = s->sdma->bd[s->sdma->outdex].data - s->period_start;*/
• count = s->period_current_pt - s->period_start;
• return bytes_to_frames(substream->runtime, count);

+}

+static struct snd_pcm_ops psc_i2s_pcm_ops = {

• .open = psc_i2s_pcm_open,
• .close = psc_i2s_pcm_close,
• .ioctl = snd_pcm_lib_ioctl,
• .pointer = psc_i2s_pcm_pointer,

+};

+static u64 psc_i2s_pcm_dmamask = 0xffffffff; +static int psc_i2s_pcm_new(struct snd_card *card, struct snd_soc_codec_dai *dai,

• 	   struct snd_pcm *pcm)
  

+{

• struct snd_soc_pcm_runtime *rtd = pcm->private_data;
• size_t size = psc_i2s_pcm_hardware.buffer_bytes_max;
• int rc = 0;
• dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_new(card=%p, dai=%p, pcm=%p)\n",

• card, dai, pcm);
  

• if (!card->dev->dma_mask)

• card->dev->dma_mask = &psc_i2s_pcm_dmamask;
  

• if (!card->dev->coherent_dma_mask)

• card->dev->coherent_dma_mask = 0xffffffff;
  

• rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,

• 		 &pcm->streams[0].substream->dma_buffer);
  

• if (rc) {

• dev_err(card->dev, "Cannot alloc playback DMA buffer\n");
  

• return -ENOMEM;
  

• }
• rc = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev, size,

• 		 &pcm->streams[1].substream->dma_buffer);
  

• if (rc) {

• snd_dma_free_pages(&pcm->streams[0].substream->dma_buffer);
  

• dev_err(card->dev, "Can't allocate capture DMA buffer\n");
  

• return -ENOMEM;
  

• }
• return 0;

+}

+static void psc_i2s_pcm_free(struct snd_pcm *pcm) +{

• struct snd_soc_pcm_runtime *rtd = pcm->private_data;
• struct snd_pcm_substream *substream;
• int stream;
• dev_dbg(rtd->socdev->dev, "psc_i2s_pcm_free(pcm=%p)\n", pcm);
• for (stream = 0; stream < 2; stream++) {

• substream = pcm->streams[stream].substream;
  

• if (substream) {
  

• 	snd_dma_free_pages(&substream->dma_buffer);
  

• 	substream->dma_buffer.area = NULL;
  

• 	substream->dma_buffer.addr = 0;
  

• }
  

• }

+}

+struct snd_soc_platform psc_i2s_pcm_soc_platform = {

• .name = "mpc5200-psc-audio",
• .pcm_ops = &psc_i2s_pcm_ops,
• .pcm_new = &psc_i2s_pcm_new,
• .pcm_free = &psc_i2s_pcm_free,

+};

+/* ---------------------------------------------------------------------

• • Sysfs attributes for debugging
• */

+static ssize_t psc_i2s_status_show(struct device *dev,

• 	   struct device_attribute *attr, char *buf)
  

+{

• struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
• return sprintf(buf, "status=%.4x sicr=%.8x rfnum=%i rfstat=0x%.4x tfnum=%i tfstat=0x%.4x\n",

• 	in_be16(&psc_i2s->psc_regs->sr_csr.status),
  

• 	in_be32(&psc_i2s->psc_regs->sicr),
  

• 	in_be16(&psc_i2s->fifo_regs->rfnum) & 0x1ff,
  

• 	in_be16(&psc_i2s->fifo_regs->rfstat),
  

• 	in_be16(&psc_i2s->fifo_regs->tfnum) & 0x1ff,
  

• 	in_be16(&psc_i2s->fifo_regs->tfstat));
  

+}

+static int * psc_i2s_get_stat_attr(struct psc_i2s *psc_i2s,

• 		   const char *name)
  

+{

• if (strcmp(name, "playback_underrun") == 0)

• return &psc_i2s->stats.underrun_count;
  

• if (strcmp(name, "capture_overrun") == 0)

• return &psc_i2s->stats.overrun_count;
  

• return NULL;

+}

+static ssize_t psc_i2s_stat_show(struct device *dev,

• 		 struct device_attribute *attr, char *buf)
  

+{

• struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
• int *attrib;
• attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
• if (!attrib)

• return 0;
  

• return sprintf(buf, "%i\n", *attrib);

+}

+static ssize_t psc_i2s_stat_store(struct device *dev,

• 		  struct device_attribute *attr,
  

• 		  const char *buf,
  

• 		  size_t count)
  

+{

• struct psc_i2s *psc_i2s = dev_get_drvdata(dev);
• int *attrib;
• attrib = psc_i2s_get_stat_attr(psc_i2s, attr->attr.name);
• if (!attrib)

• return 0;
  

• *attrib = simple_strtoul(buf, NULL, 0);
• return count;

+}

+DEVICE_ATTR(status, 0644, psc_i2s_status_show, NULL); +DEVICE_ATTR(playback_underrun, 0644, psc_i2s_stat_show,psc_i2s_stat_store); +DEVICE_ATTR(capture_overrun, 0644, psc_i2s_stat_show, psc_i2s_stat_store);

+/* ---------------------------------------------------------------------

• • OF platform bus binding code:
• • • Probe/remove operations
• • • OF device match table
• */

+static int __devinit psc_i2s_of_probe(struct of_device *op,

• 		      const struct of_device_id *match)
  

+{

• phys_addr_t fifo;
• struct psc_i2s *psc_i2s;
• struct resource res;
• int size, psc_id, irq, rc;
• const __be32 *prop;
• void __iomem *regs;
• dev_dbg(&op->dev, "probing psc i2s device\n");
• /* Get the PSC ID */
• prop = of_get_property(op->node, "cell-index", &size);
• if (!prop || size < sizeof *prop)

• return -ENODEV;
  

• psc_id = be32_to_cpu(*prop);
• /* Fetch the registers and IRQ of the PSC */
• irq = irq_of_parse_and_map(op->node, 0);
• if (of_address_to_resource(op->node, 0, &res)) {

• dev_err(&op->dev, "Missing reg property\n");
  

• return -ENODEV;
  

• }
• regs = ioremap(res.start, 1 + res.end - res.start);
• if (!regs) {

• dev_err(&op->dev, "Could not map registers\n");
  

• return -ENODEV;
  

• }
• /* Allocate and initialize the driver private data */
• psc_i2s = kzalloc(sizeof *psc_i2s, GFP_KERNEL);
• if (!psc_i2s) {

• iounmap(regs);
  

• return -ENOMEM;
  

• }
• spin_lock_init(&psc_i2s->lock);
• psc_i2s->irq = irq;
• psc_i2s->psc_regs = regs;
• psc_i2s->fifo_regs = regs + sizeof *psc_i2s->psc_regs;
• psc_i2s->dev = &op->dev;
• psc_i2s->playback_stream.psc_i2s = psc_i2s;
• psc_i2s->capture_stream.psc_i2s = psc_i2s;
• snprintf(psc_i2s->name, sizeof psc_i2s->name, "PSC%u", psc_id+1);
• /* Fill out the CPU DAI structure */
• memcpy(&psc_i2s->dai, &psc_i2s_dai_template, sizeof psc_i2s->dai);
• psc_i2s->dai.private_data = psc_i2s;
• psc_i2s->dai.name = psc_i2s->name;
• psc_i2s->dai.id = psc_id;
• /* Find the address of the fifo data registers and setup the

• * DMA tasks */
  

• fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
• psc_i2s->capture_stream.bcom_task =

• bcom_psc_gen_bd_rx_init(psc_id, 10, fifo, 512);
  

• psc_i2s->playback_stream.bcom_task =

• bcom_psc_gen_bd_tx_init(psc_id, 10, fifo);
  

• if (!psc_i2s->capture_stream.bcom_task ||

•    !psc_i2s->playback_stream.bcom_task) {
  

• dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
  

• iounmap(regs);
  

• kfree(psc_i2s);
  

• return -ENODEV;
  

• }
• /* Save what we've done so it can be found again later */
• dev_set_drvdata(&op->dev, psc_i2s);
• /* Register the SYSFS files */
• rc = device_create_file(psc_i2s->dev, &dev_attr_status);
• rc = device_create_file(psc_i2s->dev, &dev_attr_capture_overrun);
• rc = device_create_file(psc_i2s->dev, &dev_attr_playback_underrun);
• if (rc)

• dev_info(psc_i2s->dev, "error creating sysfs files\n");
  

• /* Tell the ASoC OF helpers about it */
• of_snd_soc_register_platform(&psc_i2s_pcm_soc_platform, op->node,

• 		     &psc_i2s->dai);
  

• return 0;

+}

+static int __devexit psc_i2s_of_remove(struct of_device *op) +{

• struct psc_i2s *psc_i2s = dev_get_drvdata(&op->dev);
• dev_dbg(&op->dev, "psc_i2s_remove()\n");
• bcom_gen_bd_rx_release(psc_i2s->capture_stream.bcom_task);
• bcom_gen_bd_tx_release(psc_i2s->playback_stream.bcom_task);
• iounmap(psc_i2s->psc_regs);
• iounmap(psc_i2s->fifo_regs);
• kfree(psc_i2s);
• dev_set_drvdata(&op->dev, NULL);
• return 0;

+}

+/* Match table for of_platform binding */ +static struct of_device_id psc_i2s_match[] __devinitdata = {

• { .compatible = "fsl,mpc5200-psc-i2s", },
• {}

+}; +MODULE_DEVICE_TABLE(of, psc_i2s_match);

+static struct of_platform_driver psc_i2s_driver = {

• .match_table = psc_i2s_match,
• .probe = psc_i2s_of_probe,
• .remove = __devexit_p(psc_i2s_of_remove),
• .driver = {

• .name = "mpc5200-psc-i2s",
  

• .owner = THIS_MODULE,
  

• },

+};

+/* ---------------------------------------------------------------------

• • Module setup and teardown; simply register the of_platform driver
• • for the PSC in I2S mode.
• */

+static int __init psc_i2s_init(void) +{

• return of_register_platform_driver(&psc_i2s_driver);

+} +module_init(psc_i2s_init);

+static void __exit psc_i2s_exit(void) +{

• of_unregister_platform_driver(&psc_i2s_driver);

+} +module_exit(psc_i2s_exit);

---

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