--- /dev/null
+/*
+ * DesignWare HDMI audio driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Written and tested against the Designware HDMI Tx found in iMX6.
+ */
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <drm/bridge/dw_hdmi.h>
+
+#include <sound/asoundef.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_iec958.h>
+
+#include "dw_hdmi-audio.h"
+
+#define DRIVER_NAME "dw-hdmi-ahb-audio"
+
+/* Provide some bits rather than bit offsets */
+enum {
+ HDMI_AHB_DMA_CONF0_SW_FIFO_RST = BIT(7),
+ HDMI_AHB_DMA_CONF0_EN_HLOCK = BIT(3),
+ HDMI_AHB_DMA_START_START = BIT(0),
+ HDMI_AHB_DMA_STOP_STOP = BIT(0),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR = BIT(5),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST = BIT(4),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY = BIT(3),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE = BIT(2),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL =
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_ERROR |
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_LOST |
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_RETRY |
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE |
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFFULL |
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0_BUFFEMPTY,
+ HDMI_IH_AHBDMAAUD_STAT0_ERROR = BIT(5),
+ HDMI_IH_AHBDMAAUD_STAT0_LOST = BIT(4),
+ HDMI_IH_AHBDMAAUD_STAT0_RETRY = BIT(3),
+ HDMI_IH_AHBDMAAUD_STAT0_DONE = BIT(2),
+ HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL = BIT(1),
+ HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY = BIT(0),
+ HDMI_IH_AHBDMAAUD_STAT0_ALL =
+ HDMI_IH_AHBDMAAUD_STAT0_ERROR |
+ HDMI_IH_AHBDMAAUD_STAT0_LOST |
+ HDMI_IH_AHBDMAAUD_STAT0_RETRY |
+ HDMI_IH_AHBDMAAUD_STAT0_DONE |
+ HDMI_IH_AHBDMAAUD_STAT0_BUFFFULL |
+ HDMI_IH_AHBDMAAUD_STAT0_BUFFEMPTY,
+ HDMI_AHB_DMA_CONF0_INCR16 = 2 << 1,
+ HDMI_AHB_DMA_CONF0_INCR8 = 1 << 1,
+ HDMI_AHB_DMA_CONF0_INCR4 = 0,
+ HDMI_AHB_DMA_CONF0_BURST_MODE = BIT(0),
+ HDMI_AHB_DMA_MASK_DONE = BIT(7),
+ HDMI_REVISION_ID = 0x0001,
+ HDMI_IH_AHBDMAAUD_STAT0 = 0x0109,
+ HDMI_IH_MUTE_AHBDMAAUD_STAT0 = 0x0189,
+ HDMI_AHB_DMA_CONF0 = 0x3600,
+ HDMI_AHB_DMA_START = 0x3601,
+ HDMI_AHB_DMA_STOP = 0x3602,
+ HDMI_AHB_DMA_THRSLD = 0x3603,
+ HDMI_AHB_DMA_STRADDR0 = 0x3604,
+ HDMI_AHB_DMA_STPADDR0 = 0x3608,
+ HDMI_AHB_DMA_MASK = 0x3614,
+ HDMI_AHB_DMA_POL = 0x3615,
+ HDMI_AHB_DMA_CONF1 = 0x3616,
+ HDMI_AHB_DMA_BUFFPOL = 0x361a,
+};
+
+struct snd_dw_hdmi {
+ struct snd_card *card;
+ struct snd_pcm *pcm;
+ spinlock_t lock;
+ struct dw_hdmi_audio_data data;
+ struct snd_pcm_substream *substream;
+ void (*reformat)(struct snd_dw_hdmi *, size_t, size_t);
+ void *buf_src;
+ void *buf_dst;
+ dma_addr_t buf_addr;
+ unsigned buf_offset;
+ unsigned buf_period;
+ unsigned buf_size;
+ unsigned channels;
+ u8 revision;
+ u8 iec_offset;
+ u8 cs[192][8];
+};
+
+static void dw_hdmi_writel(u32 val, void __iomem *ptr)
+{
+ writeb_relaxed(val, ptr);
+ writeb_relaxed(val >> 8, ptr + 1);
+ writeb_relaxed(val >> 16, ptr + 2);
+ writeb_relaxed(val >> 24, ptr + 3);
+}
+
+/*
+ * Convert to hardware format: The userspace buffer contains IEC958 samples,
+ * with the PCUV bits in bits 31..28 and audio samples in bits 27..4. We
+ * need these to be in bits 27..24, with the IEC B bit in bit 28, and audio
+ * samples in 23..0.
+ *
+ * Default preamble in bits 3..0: 8 = block start, 4 = even 2 = odd
+ *
+ * Ideally, we could do with having the data properly formatted in userspace.
+ */
+static void dw_hdmi_reformat_iec958(struct snd_dw_hdmi *dw,
+ size_t offset, size_t bytes)
+{
+ u32 *src = dw->buf_src + offset;
+ u32 *dst = dw->buf_dst + offset;
+ u32 *end = dw->buf_src + offset + bytes;
+
+ do {
+ u32 b, sample = *src++;
+
+ b = (sample & 8) << (28 - 3);
+
+ sample >>= 4;
+
+ *dst++ = sample | b;
+ } while (src < end);
+}
+
+static u32 parity(u32 sample)
+{
+ sample ^= sample >> 16;
+ sample ^= sample >> 8;
+ sample ^= sample >> 4;
+ sample ^= sample >> 2;
+ sample ^= sample >> 1;
+ return (sample & 1) << 27;
+}
+
+static void dw_hdmi_reformat_s24(struct snd_dw_hdmi *dw,
+ size_t offset, size_t bytes)
+{
+ u32 *src = dw->buf_src + offset;
+ u32 *dst = dw->buf_dst + offset;
+ u32 *end = dw->buf_src + offset + bytes;
+
+ do {
+ unsigned i;
+ u8 *cs;
+
+ cs = dw->cs[dw->iec_offset++];
+ if (dw->iec_offset >= 192)
+ dw->iec_offset = 0;
+
+ i = dw->channels;
+ do {
+ u32 sample = *src++;
+
+ sample &= ~0xff000000;
+ sample |= *cs++ << 24;
+ sample |= parity(sample & ~0xf8000000);
+
+ *dst++ = sample;
+ } while (--i);
+ } while (src < end);
+}
+
+static void dw_hdmi_create_cs(struct snd_dw_hdmi *dw,
+ struct snd_pcm_runtime *runtime)
+{
+ u8 cs[4];
+ unsigned ch, i, j;
+
+ snd_pcm_create_iec958_consumer(runtime, cs, sizeof(cs));
+
+ memset(dw->cs, 0, sizeof(dw->cs));
+
+ for (ch = 0; ch < 8; ch++) {
+ cs[2] &= ~IEC958_AES2_CON_CHANNEL;
+ cs[2] |= (ch + 1) << 4;
+
+ for (i = 0; i < ARRAY_SIZE(cs); i++) {
+ unsigned c = cs[i];
+
+ for (j = 0; j < 8; j++, c >>= 1)
+ dw->cs[i * 8 + j][ch] = (c & 1) << 2;
+ }
+ }
+ dw->cs[0][0] |= BIT(4);
+}
+
+static void dw_hdmi_start_dma(struct snd_dw_hdmi *dw)
+{
+ void __iomem *base = dw->data.base;
+ unsigned offset = dw->buf_offset;
+ unsigned period = dw->buf_period;
+ u32 start, stop;
+
+ dw->reformat(dw, offset, period);
+
+ /* Clear all irqs before enabling irqs and starting DMA */
+ writeb_relaxed(HDMI_IH_AHBDMAAUD_STAT0_ALL,
+ base + HDMI_IH_AHBDMAAUD_STAT0);
+
+ start = dw->buf_addr + offset;
+ stop = start + period - 1;
+
+ /* Setup the hardware start/stop addresses */
+ dw_hdmi_writel(start, base + HDMI_AHB_DMA_STRADDR0);
+ dw_hdmi_writel(stop, base + HDMI_AHB_DMA_STPADDR0);
+
+ writeb_relaxed((u8)~HDMI_AHB_DMA_MASK_DONE, base + HDMI_AHB_DMA_MASK);
+ writeb(HDMI_AHB_DMA_START_START, base + HDMI_AHB_DMA_START);
+
+ offset += period;
+ if (offset >= dw->buf_size)
+ offset = 0;
+ dw->buf_offset = offset;
+}
+
+static void dw_hdmi_stop_dma(struct snd_dw_hdmi *dw)
+{
+ /* Disable interrupts before disabling DMA */
+ writeb_relaxed(~0, dw->data.base + HDMI_AHB_DMA_MASK);
+ writeb_relaxed(HDMI_AHB_DMA_STOP_STOP, dw->data.base + HDMI_AHB_DMA_STOP);
+}
+
+static irqreturn_t snd_dw_hdmi_irq(int irq, void *data)
+{
+ struct snd_dw_hdmi *dw = data;
+ struct snd_pcm_substream *substream;
+ unsigned stat;
+
+ stat = readb_relaxed(dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
+ if (!stat)
+ return IRQ_NONE;
+
+ writeb_relaxed(stat, dw->data.base + HDMI_IH_AHBDMAAUD_STAT0);
+
+ substream = dw->substream;
+ if (stat & HDMI_IH_AHBDMAAUD_STAT0_DONE && substream) {
+ snd_pcm_period_elapsed(substream);
+
+ spin_lock(&dw->lock);
+ if (dw->substream)
+ dw_hdmi_start_dma(dw);
+ spin_unlock(&dw->lock);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct snd_pcm_hardware dw_hdmi_hw = {
+ .info = SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_BLOCK_TRANSFER |
+ SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_MMAP_VALID,
+ .formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE |
+ SNDRV_PCM_FMTBIT_S24_LE,
+ .rates = SNDRV_PCM_RATE_32000 |
+ SNDRV_PCM_RATE_44100 |
+ SNDRV_PCM_RATE_48000 |
+ SNDRV_PCM_RATE_88200 |
+ SNDRV_PCM_RATE_96000 |
+ SNDRV_PCM_RATE_176400 |
+ SNDRV_PCM_RATE_192000,
+ .channels_min = 2,
+ .channels_max = 8,
+ .buffer_bytes_max = 64 * 1024,
+ .period_bytes_min = 256,
+ .period_bytes_max = 8192, /* ERR004323: must limit to 8k */
+ .periods_min = 2,
+ .periods_max = 16,
+ .fifo_size = 0,
+};
+
+static int dw_hdmi_open(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_dw_hdmi *dw = substream->private_data;
+ void __iomem *base = dw->data.base;
+ int ret;
+
+ runtime->hw = dw_hdmi_hw;
+
+ ret = snd_pcm_limit_hw_rates(runtime);
+ if (ret < 0)
+ return ret;
+
+ ret = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+ if (ret < 0)
+ return ret;
+
+ /* Clear FIFO */
+ writeb_relaxed(HDMI_AHB_DMA_CONF0_SW_FIFO_RST,
+ base + HDMI_AHB_DMA_CONF0);
+
+ /* Configure interrupt polarities */
+ writeb_relaxed(~0, base + HDMI_AHB_DMA_POL);
+ writeb_relaxed(~0, base + HDMI_AHB_DMA_BUFFPOL);
+
+ /* Keep interrupts masked, and clear any pending */
+ writeb_relaxed(~0, base + HDMI_AHB_DMA_MASK);
+ writeb_relaxed(~0, base + HDMI_IH_AHBDMAAUD_STAT0);
+
+ ret = request_irq(dw->data.irq, snd_dw_hdmi_irq, IRQF_SHARED,
+ "dw-hdmi-audio", dw);
+ if (ret)
+ return ret;
+
+ /* Un-mute done interrupt */
+ writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL &
+ ~HDMI_IH_MUTE_AHBDMAAUD_STAT0_DONE,
+ base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+ return 0;
+}
+
+static int dw_hdmi_close(struct snd_pcm_substream *substream)
+{
+ struct snd_dw_hdmi *dw = substream->private_data;
+
+ /* Mute all interrupts */
+ writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+ dw->data.base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+
+ free_irq(dw->data.irq, dw);
+
+ return 0;
+}
+
+static int dw_hdmi_hw_free(struct snd_pcm_substream *substream)
+{
+ return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int dw_hdmi_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ return snd_pcm_lib_alloc_vmalloc_buffer(substream,
+ params_buffer_bytes(params));
+}
+
+static int dw_hdmi_prepare(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_dw_hdmi *dw = substream->private_data;
+ u8 threshold, conf0, conf1;
+
+ /* Setup as per 3.0.5 FSL 4.1.0 BSP */
+ switch (dw->revision) {
+ case 0x0a:
+ conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
+ HDMI_AHB_DMA_CONF0_INCR4;
+ if (runtime->channels == 2)
+ threshold = 126;
+ else
+ threshold = 124;
+ break;
+ case 0x1a:
+ conf0 = HDMI_AHB_DMA_CONF0_BURST_MODE |
+ HDMI_AHB_DMA_CONF0_INCR8;
+ threshold = 128;
+ break;
+ default:
+ /* NOTREACHED */
+ return -EINVAL;
+ }
+
+ dw_hdmi_set_sample_rate(dw->data.hdmi, runtime->rate);
+
+ /* Minimum number of bytes in the fifo. */
+ runtime->hw.fifo_size = threshold * 32;
+
+ conf0 |= HDMI_AHB_DMA_CONF0_EN_HLOCK;
+ conf1 = (1 << runtime->channels) - 1;
+
+ writeb_relaxed(threshold, dw->data.base + HDMI_AHB_DMA_THRSLD);
+ writeb_relaxed(conf0, dw->data.base + HDMI_AHB_DMA_CONF0);
+ writeb_relaxed(conf1, dw->data.base + HDMI_AHB_DMA_CONF1);
+
+ switch (runtime->format) {
+ case SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE:
+ dw->reformat = dw_hdmi_reformat_iec958;
+ break;
+ case SNDRV_PCM_FORMAT_S24_LE:
+ dw_hdmi_create_cs(dw, runtime);
+ dw->reformat = dw_hdmi_reformat_s24;
+ break;
+ }
+ dw->iec_offset = 0;
+ dw->channels = runtime->channels;
+ dw->buf_src = runtime->dma_area;
+ dw->buf_dst = substream->dma_buffer.area;
+ dw->buf_addr = substream->dma_buffer.addr;
+ dw->buf_period = snd_pcm_lib_period_bytes(substream);
+ dw->buf_size = snd_pcm_lib_buffer_bytes(substream);
+
+ return 0;
+}
+
+static int dw_hdmi_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+ struct snd_dw_hdmi *dw = substream->private_data;
+ unsigned long flags;
+ int ret = 0;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ spin_lock_irqsave(&dw->lock, flags);
+ dw->buf_offset = 0;
+ dw->substream = substream;
+ dw_hdmi_start_dma(dw);
+ dw_hdmi_audio_enable(dw->data.hdmi);
+ spin_unlock_irqrestore(&dw->lock, flags);
+ substream->runtime->delay = substream->runtime->period_size;
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ spin_lock_irqsave(&dw->lock, flags);
+ dw->substream = NULL;
+ dw_hdmi_stop_dma(dw);
+ dw_hdmi_audio_disable(dw->data.hdmi);
+ spin_unlock_irqrestore(&dw->lock, flags);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static snd_pcm_uframes_t dw_hdmi_pointer(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_dw_hdmi *dw = substream->private_data;
+
+ /*
+ * We are unable to report the exact hardware position as
+ * reading the 32-bit DMA position using 8-bit reads is racy.
+ */
+ return bytes_to_frames(runtime, dw->buf_offset);
+}
+
+static struct snd_pcm_ops snd_dw_hdmi_ops = {
+ .open = dw_hdmi_open,
+ .close = dw_hdmi_close,
+ .ioctl = snd_pcm_lib_ioctl,
+ .hw_params = dw_hdmi_hw_params,
+ .hw_free = dw_hdmi_hw_free,
+ .prepare = dw_hdmi_prepare,
+ .trigger = dw_hdmi_trigger,
+ .pointer = dw_hdmi_pointer,
+ .page = snd_pcm_lib_get_vmalloc_page,
+};
+
+static int snd_dw_hdmi_probe(struct platform_device *pdev)
+{
+ const struct dw_hdmi_audio_data *data = pdev->dev.platform_data;
+ struct device *dev = pdev->dev.parent;
+ struct snd_dw_hdmi *dw;
+ struct snd_card *card;
+ struct snd_pcm *pcm;
+ unsigned revision;
+ int ret;
+
+ writeb_relaxed(HDMI_IH_MUTE_AHBDMAAUD_STAT0_ALL,
+ data->base + HDMI_IH_MUTE_AHBDMAAUD_STAT0);
+ revision = readb_relaxed(data->base + HDMI_REVISION_ID);
+ if (revision != 0x0a && revision != 0x1a) {
+ dev_err(dev, "dw-hdmi-audio: unknown revision 0x%02x\n",
+ revision);
+ return -ENXIO;
+ }
+
+ ret = snd_card_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+ THIS_MODULE, sizeof(struct snd_dw_hdmi), &card);
+ if (ret < 0)
+ return ret;
+
+ strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
+ strlcpy(card->shortname, "DW-HDMI", sizeof(card->shortname));
+ snprintf(card->longname, sizeof(card->longname),
+ "%s rev 0x%02x, irq %d", card->shortname, revision,
+ data->irq);
+
+ dw = card->private_data;
+ dw->card = card;
+ dw->data = *data;
+ dw->revision = revision;
+
+ spin_lock_init(&dw->lock);
+
+ ret = snd_pcm_new(card, "DW HDMI", 0, 1, 0, &pcm);
+ if (ret < 0)
+ goto err;
+
+ dw->pcm = pcm;
+ pcm->private_data = dw;
+ strlcpy(pcm->name, DRIVER_NAME, sizeof(pcm->name));
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_dw_hdmi_ops);
+
+ snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
+ dev, 64 * 1024, 64 * 1024);
+
+ ret = snd_card_register(card);
+ if (ret < 0)
+ goto err;
+
+ platform_set_drvdata(pdev, dw);
+
+ return 0;
+
+err:
+ snd_card_free(card);
+ return ret;
+}
+
+static int snd_dw_hdmi_remove(struct platform_device *pdev)
+{
+ struct snd_dw_hdmi *dw = platform_get_drvdata(pdev);
+
+ snd_card_free(dw->card);
+
+ return 0;
+}
+
+#if defined(CONFIG_PM_SLEEP) && defined(IS_NOT_BROKEN)
+/*
+ * This code is fine, but requires implementation in the dw_hdmi_trigger()
+ * method which is currently missing as I have no way to test this.
+ */
+static int snd_dw_hdmi_suspend(struct device *dev)
+{
+ struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
+
+ snd_power_change_state(dw->card, SNDRV_CTL_POWER_D3cold);
+ snd_pcm_suspend_all(dw->pcm);
+
+ return 0;
+}
+
+static int snd_dw_hdmi_resume(struct device *dev)
+{
+ struct snd_dw_hdmi *dw = dev_get_drvdata(dev);
+
+ snd_power_change_state(dw->card, SNDRV_CTL_POWER_D0);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(snd_dw_hdmi_pm, snd_dw_hdmi_suspend,
+ snd_dw_hdmi_resume);
+#define PM_OPS &snd_dw_hdmi_pm
+#else
+#define PM_OPS NULL
+#endif
+
+static struct platform_driver snd_dw_hdmi_driver = {
+ .probe = snd_dw_hdmi_probe,
+ .remove = snd_dw_hdmi_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .pm = PM_OPS,
+ },
+};
+
+module_platform_driver(snd_dw_hdmi_driver);
+
+MODULE_AUTHOR("Russell King <rmk+kernel@arm.linux.org.uk>");
+MODULE_DESCRIPTION("Synopsis Designware HDMI AHB ALSA interface");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);