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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /sound/hda/hdac_controller.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'sound/hda/hdac_controller.c')
-rw-r--r--sound/hda/hdac_controller.c620
1 files changed, 620 insertions, 0 deletions
diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
new file mode 100644
index 000000000..a65e8c0c6
--- /dev/null
+++ b/sound/hda/hdac_controller.c
@@ -0,0 +1,620 @@
+/*
+ * HD-audio controller helpers
+ */
+
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <sound/core.h>
+#include <sound/hdaudio.h>
+#include <sound/hda_register.h>
+
+/* clear CORB read pointer properly */
+static void azx_clear_corbrp(struct hdac_bus *bus)
+{
+ int timeout;
+
+ for (timeout = 1000; timeout > 0; timeout--) {
+ if (snd_hdac_chip_readw(bus, CORBRP) & AZX_CORBRP_RST)
+ break;
+ udelay(1);
+ }
+ if (timeout <= 0)
+ dev_err(bus->dev, "CORB reset timeout#1, CORBRP = %d\n",
+ snd_hdac_chip_readw(bus, CORBRP));
+
+ snd_hdac_chip_writew(bus, CORBRP, 0);
+ for (timeout = 1000; timeout > 0; timeout--) {
+ if (snd_hdac_chip_readw(bus, CORBRP) == 0)
+ break;
+ udelay(1);
+ }
+ if (timeout <= 0)
+ dev_err(bus->dev, "CORB reset timeout#2, CORBRP = %d\n",
+ snd_hdac_chip_readw(bus, CORBRP));
+}
+
+/**
+ * snd_hdac_bus_init_cmd_io - set up CORB/RIRB buffers
+ * @bus: HD-audio core bus
+ */
+void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
+{
+ WARN_ON_ONCE(!bus->rb.area);
+
+ spin_lock_irq(&bus->reg_lock);
+ /* CORB set up */
+ bus->corb.addr = bus->rb.addr;
+ bus->corb.buf = (__le32 *)bus->rb.area;
+ snd_hdac_chip_writel(bus, CORBLBASE, (u32)bus->corb.addr);
+ snd_hdac_chip_writel(bus, CORBUBASE, upper_32_bits(bus->corb.addr));
+
+ /* set the corb size to 256 entries (ULI requires explicitly) */
+ snd_hdac_chip_writeb(bus, CORBSIZE, 0x02);
+ /* set the corb write pointer to 0 */
+ snd_hdac_chip_writew(bus, CORBWP, 0);
+
+ /* reset the corb hw read pointer */
+ snd_hdac_chip_writew(bus, CORBRP, AZX_CORBRP_RST);
+ if (!bus->corbrp_self_clear)
+ azx_clear_corbrp(bus);
+
+ /* enable corb dma */
+ snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
+
+ /* RIRB set up */
+ bus->rirb.addr = bus->rb.addr + 2048;
+ bus->rirb.buf = (__le32 *)(bus->rb.area + 2048);
+ bus->rirb.wp = bus->rirb.rp = 0;
+ memset(bus->rirb.cmds, 0, sizeof(bus->rirb.cmds));
+ snd_hdac_chip_writel(bus, RIRBLBASE, (u32)bus->rirb.addr);
+ snd_hdac_chip_writel(bus, RIRBUBASE, upper_32_bits(bus->rirb.addr));
+
+ /* set the rirb size to 256 entries (ULI requires explicitly) */
+ snd_hdac_chip_writeb(bus, RIRBSIZE, 0x02);
+ /* reset the rirb hw write pointer */
+ snd_hdac_chip_writew(bus, RIRBWP, AZX_RIRBWP_RST);
+ /* set N=1, get RIRB response interrupt for new entry */
+ snd_hdac_chip_writew(bus, RINTCNT, 1);
+ /* enable rirb dma and response irq */
+ snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);
+ spin_unlock_irq(&bus->reg_lock);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
+
+/* wait for cmd dmas till they are stopped */
+static void hdac_wait_for_cmd_dmas(struct hdac_bus *bus)
+{
+ unsigned long timeout;
+
+ timeout = jiffies + msecs_to_jiffies(100);
+ while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
+ && time_before(jiffies, timeout))
+ udelay(10);
+
+ timeout = jiffies + msecs_to_jiffies(100);
+ while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
+ && time_before(jiffies, timeout))
+ udelay(10);
+}
+
+/**
+ * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
+ * @bus: HD-audio core bus
+ */
+void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
+{
+ spin_lock_irq(&bus->reg_lock);
+ /* disable ringbuffer DMAs */
+ snd_hdac_chip_writeb(bus, RIRBCTL, 0);
+ snd_hdac_chip_writeb(bus, CORBCTL, 0);
+ spin_unlock_irq(&bus->reg_lock);
+
+ hdac_wait_for_cmd_dmas(bus);
+
+ spin_lock_irq(&bus->reg_lock);
+ /* disable unsolicited responses */
+ snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
+ spin_unlock_irq(&bus->reg_lock);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_cmd_io);
+
+static unsigned int azx_command_addr(u32 cmd)
+{
+ unsigned int addr = cmd >> 28;
+
+ if (snd_BUG_ON(addr >= HDA_MAX_CODECS))
+ addr = 0;
+ return addr;
+}
+
+/**
+ * snd_hdac_bus_send_cmd - send a command verb via CORB
+ * @bus: HD-audio core bus
+ * @val: encoded verb value to send
+ *
+ * Returns zero for success or a negative error code.
+ */
+int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
+{
+ unsigned int addr = azx_command_addr(val);
+ unsigned int wp, rp;
+
+ spin_lock_irq(&bus->reg_lock);
+
+ bus->last_cmd[azx_command_addr(val)] = val;
+
+ /* add command to corb */
+ wp = snd_hdac_chip_readw(bus, CORBWP);
+ if (wp == 0xffff) {
+ /* something wrong, controller likely turned to D3 */
+ spin_unlock_irq(&bus->reg_lock);
+ return -EIO;
+ }
+ wp++;
+ wp %= AZX_MAX_CORB_ENTRIES;
+
+ rp = snd_hdac_chip_readw(bus, CORBRP);
+ if (wp == rp) {
+ /* oops, it's full */
+ spin_unlock_irq(&bus->reg_lock);
+ return -EAGAIN;
+ }
+
+ bus->rirb.cmds[addr]++;
+ bus->corb.buf[wp] = cpu_to_le32(val);
+ snd_hdac_chip_writew(bus, CORBWP, wp);
+
+ spin_unlock_irq(&bus->reg_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
+
+#define AZX_RIRB_EX_UNSOL_EV (1<<4)
+
+/**
+ * snd_hdac_bus_update_rirb - retrieve RIRB entries
+ * @bus: HD-audio core bus
+ *
+ * Usually called from interrupt handler.
+ */
+void snd_hdac_bus_update_rirb(struct hdac_bus *bus)
+{
+ unsigned int rp, wp;
+ unsigned int addr;
+ u32 res, res_ex;
+
+ wp = snd_hdac_chip_readw(bus, RIRBWP);
+ if (wp == 0xffff) {
+ /* something wrong, controller likely turned to D3 */
+ return;
+ }
+
+ if (wp == bus->rirb.wp)
+ return;
+ bus->rirb.wp = wp;
+
+ while (bus->rirb.rp != wp) {
+ bus->rirb.rp++;
+ bus->rirb.rp %= AZX_MAX_RIRB_ENTRIES;
+
+ rp = bus->rirb.rp << 1; /* an RIRB entry is 8-bytes */
+ res_ex = le32_to_cpu(bus->rirb.buf[rp + 1]);
+ res = le32_to_cpu(bus->rirb.buf[rp]);
+ addr = res_ex & 0xf;
+ if (addr >= HDA_MAX_CODECS) {
+ dev_err(bus->dev,
+ "spurious response %#x:%#x, rp = %d, wp = %d",
+ res, res_ex, bus->rirb.rp, wp);
+ snd_BUG();
+ } else if (res_ex & AZX_RIRB_EX_UNSOL_EV)
+ snd_hdac_bus_queue_event(bus, res, res_ex);
+ else if (bus->rirb.cmds[addr]) {
+ bus->rirb.res[addr] = res;
+ bus->rirb.cmds[addr]--;
+ } else {
+ dev_err_ratelimited(bus->dev,
+ "spurious response %#x:%#x, last cmd=%#08x\n",
+ res, res_ex, bus->last_cmd[addr]);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_update_rirb);
+
+/**
+ * snd_hdac_bus_get_response - receive a response via RIRB
+ * @bus: HD-audio core bus
+ * @addr: codec address
+ * @res: pointer to store the value, NULL when not needed
+ *
+ * Returns zero if a value is read, or a negative error code.
+ */
+int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
+ unsigned int *res)
+{
+ unsigned long timeout;
+ unsigned long loopcounter;
+
+ timeout = jiffies + msecs_to_jiffies(1000);
+
+ for (loopcounter = 0;; loopcounter++) {
+ spin_lock_irq(&bus->reg_lock);
+ if (!bus->rirb.cmds[addr]) {
+ if (res)
+ *res = bus->rirb.res[addr]; /* the last value */
+ spin_unlock_irq(&bus->reg_lock);
+ return 0;
+ }
+ spin_unlock_irq(&bus->reg_lock);
+ if (time_after(jiffies, timeout))
+ break;
+ if (loopcounter > 3000)
+ msleep(2); /* temporary workaround */
+ else {
+ udelay(10);
+ cond_resched();
+ }
+ }
+
+ return -EIO;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);
+
+#define HDAC_MAX_CAPS 10
+/**
+ * snd_hdac_bus_parse_capabilities - parse capability structure
+ * @bus: the pointer to bus object
+ *
+ * Returns 0 if successful, or a negative error code.
+ */
+int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
+{
+ unsigned int cur_cap;
+ unsigned int offset;
+ unsigned int counter = 0;
+
+ offset = snd_hdac_chip_readw(bus, LLCH);
+
+ /* Lets walk the linked capabilities list */
+ do {
+ cur_cap = _snd_hdac_chip_readl(bus, offset);
+
+ dev_dbg(bus->dev, "Capability version: 0x%x\n",
+ (cur_cap & AZX_CAP_HDR_VER_MASK) >> AZX_CAP_HDR_VER_OFF);
+
+ dev_dbg(bus->dev, "HDA capability ID: 0x%x\n",
+ (cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF);
+
+ if (cur_cap == -1) {
+ dev_dbg(bus->dev, "Invalid capability reg read\n");
+ break;
+ }
+
+ switch ((cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF) {
+ case AZX_ML_CAP_ID:
+ dev_dbg(bus->dev, "Found ML capability\n");
+ bus->mlcap = bus->remap_addr + offset;
+ break;
+
+ case AZX_GTS_CAP_ID:
+ dev_dbg(bus->dev, "Found GTS capability offset=%x\n", offset);
+ bus->gtscap = bus->remap_addr + offset;
+ break;
+
+ case AZX_PP_CAP_ID:
+ /* PP capability found, the Audio DSP is present */
+ dev_dbg(bus->dev, "Found PP capability offset=%x\n", offset);
+ bus->ppcap = bus->remap_addr + offset;
+ break;
+
+ case AZX_SPB_CAP_ID:
+ /* SPIB capability found, handler function */
+ dev_dbg(bus->dev, "Found SPB capability\n");
+ bus->spbcap = bus->remap_addr + offset;
+ break;
+
+ case AZX_DRSM_CAP_ID:
+ /* DMA resume capability found, handler function */
+ dev_dbg(bus->dev, "Found DRSM capability\n");
+ bus->drsmcap = bus->remap_addr + offset;
+ break;
+
+ default:
+ dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
+ cur_cap = 0;
+ break;
+ }
+
+ counter++;
+
+ if (counter > HDAC_MAX_CAPS) {
+ dev_err(bus->dev, "We exceeded HDAC capabilities!!!\n");
+ break;
+ }
+
+ /* read the offset of next capability */
+ offset = cur_cap & AZX_CAP_HDR_NXT_PTR_MASK;
+
+ } while (offset);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_parse_capabilities);
+
+/*
+ * Lowlevel interface
+ */
+
+/**
+ * snd_hdac_bus_enter_link_reset - enter link reset
+ * @bus: HD-audio core bus
+ *
+ * Enter to the link reset state.
+ */
+void snd_hdac_bus_enter_link_reset(struct hdac_bus *bus)
+{
+ unsigned long timeout;
+
+ /* reset controller */
+ snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_RESET, 0);
+
+ timeout = jiffies + msecs_to_jiffies(100);
+ while ((snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET) &&
+ time_before(jiffies, timeout))
+ usleep_range(500, 1000);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_enter_link_reset);
+
+/**
+ * snd_hdac_bus_exit_link_reset - exit link reset
+ * @bus: HD-audio core bus
+ *
+ * Exit from the link reset state.
+ */
+void snd_hdac_bus_exit_link_reset(struct hdac_bus *bus)
+{
+ unsigned long timeout;
+
+ snd_hdac_chip_updateb(bus, GCTL, 0, AZX_GCTL_RESET);
+
+ timeout = jiffies + msecs_to_jiffies(100);
+ while (!snd_hdac_chip_readb(bus, GCTL) && time_before(jiffies, timeout))
+ usleep_range(500, 1000);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_exit_link_reset);
+
+/* reset codec link */
+int snd_hdac_bus_reset_link(struct hdac_bus *bus, bool full_reset)
+{
+ if (!full_reset)
+ goto skip_reset;
+
+ /* clear STATESTS if not in reset */
+ if (snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET)
+ snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
+
+ /* reset controller */
+ snd_hdac_bus_enter_link_reset(bus);
+
+ /* delay for >= 100us for codec PLL to settle per spec
+ * Rev 0.9 section 5.5.1
+ */
+ usleep_range(500, 1000);
+
+ /* Bring controller out of reset */
+ snd_hdac_bus_exit_link_reset(bus);
+
+ /* Brent Chartrand said to wait >= 540us for codecs to initialize */
+ usleep_range(1000, 1200);
+
+ skip_reset:
+ /* check to see if controller is ready */
+ if (!snd_hdac_chip_readb(bus, GCTL)) {
+ dev_dbg(bus->dev, "controller not ready!\n");
+ return -EBUSY;
+ }
+
+ /* Accept unsolicited responses */
+ snd_hdac_chip_updatel(bus, GCTL, 0, AZX_GCTL_UNSOL);
+
+ /* detect codecs */
+ if (!bus->codec_mask) {
+ bus->codec_mask = snd_hdac_chip_readw(bus, STATESTS);
+ dev_dbg(bus->dev, "codec_mask = 0x%lx\n", bus->codec_mask);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_reset_link);
+
+/* enable interrupts */
+static void azx_int_enable(struct hdac_bus *bus)
+{
+ /* enable controller CIE and GIE */
+ snd_hdac_chip_updatel(bus, INTCTL, 0, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN);
+}
+
+/* disable interrupts */
+static void azx_int_disable(struct hdac_bus *bus)
+{
+ struct hdac_stream *azx_dev;
+
+ /* disable interrupts in stream descriptor */
+ list_for_each_entry(azx_dev, &bus->stream_list, list)
+ snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_INT_MASK, 0);
+
+ /* disable SIE for all streams */
+ snd_hdac_chip_writeb(bus, INTCTL, 0);
+
+ /* disable controller CIE and GIE */
+ snd_hdac_chip_updatel(bus, INTCTL, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN, 0);
+}
+
+/* clear interrupts */
+static void azx_int_clear(struct hdac_bus *bus)
+{
+ struct hdac_stream *azx_dev;
+
+ /* clear stream status */
+ list_for_each_entry(azx_dev, &bus->stream_list, list)
+ snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
+
+ /* clear STATESTS */
+ snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
+
+ /* clear rirb status */
+ snd_hdac_chip_writeb(bus, RIRBSTS, RIRB_INT_MASK);
+
+ /* clear int status */
+ snd_hdac_chip_writel(bus, INTSTS, AZX_INT_CTRL_EN | AZX_INT_ALL_STREAM);
+}
+
+/**
+ * snd_hdac_bus_init_chip - reset and start the controller registers
+ * @bus: HD-audio core bus
+ * @full_reset: Do full reset
+ */
+bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset)
+{
+ if (bus->chip_init)
+ return false;
+
+ /* reset controller */
+ snd_hdac_bus_reset_link(bus, full_reset);
+
+ /* clear interrupts */
+ azx_int_clear(bus);
+
+ /* initialize the codec command I/O */
+ snd_hdac_bus_init_cmd_io(bus);
+
+ /* enable interrupts after CORB/RIRB buffers are initialized above */
+ azx_int_enable(bus);
+
+ /* program the position buffer */
+ if (bus->use_posbuf && bus->posbuf.addr) {
+ snd_hdac_chip_writel(bus, DPLBASE, (u32)bus->posbuf.addr);
+ snd_hdac_chip_writel(bus, DPUBASE, upper_32_bits(bus->posbuf.addr));
+ }
+
+ bus->chip_init = true;
+ return true;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_init_chip);
+
+/**
+ * snd_hdac_bus_stop_chip - disable the whole IRQ and I/Os
+ * @bus: HD-audio core bus
+ */
+void snd_hdac_bus_stop_chip(struct hdac_bus *bus)
+{
+ if (!bus->chip_init)
+ return;
+
+ /* disable interrupts */
+ azx_int_disable(bus);
+ azx_int_clear(bus);
+
+ /* disable CORB/RIRB */
+ snd_hdac_bus_stop_cmd_io(bus);
+
+ /* disable position buffer */
+ if (bus->posbuf.addr) {
+ snd_hdac_chip_writel(bus, DPLBASE, 0);
+ snd_hdac_chip_writel(bus, DPUBASE, 0);
+ }
+
+ bus->chip_init = false;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_chip);
+
+/**
+ * snd_hdac_bus_handle_stream_irq - interrupt handler for streams
+ * @bus: HD-audio core bus
+ * @status: INTSTS register value
+ * @ask: callback to be called for woken streams
+ *
+ * Returns the bits of handled streams, or zero if no stream is handled.
+ */
+int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
+ void (*ack)(struct hdac_bus *,
+ struct hdac_stream *))
+{
+ struct hdac_stream *azx_dev;
+ u8 sd_status;
+ int handled = 0;
+
+ list_for_each_entry(azx_dev, &bus->stream_list, list) {
+ if (status & azx_dev->sd_int_sta_mask) {
+ sd_status = snd_hdac_stream_readb(azx_dev, SD_STS);
+ snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
+ handled |= 1 << azx_dev->index;
+ if (!azx_dev->substream || !azx_dev->running ||
+ !(sd_status & SD_INT_COMPLETE))
+ continue;
+ if (ack)
+ ack(bus, azx_dev);
+ }
+ }
+ return handled;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_handle_stream_irq);
+
+/**
+ * snd_hdac_bus_alloc_stream_pages - allocate BDL and other buffers
+ * @bus: HD-audio core bus
+ *
+ * Call this after assigning the all streams.
+ * Returns zero for success, or a negative error code.
+ */
+int snd_hdac_bus_alloc_stream_pages(struct hdac_bus *bus)
+{
+ struct hdac_stream *s;
+ int num_streams = 0;
+ int err;
+
+ list_for_each_entry(s, &bus->stream_list, list) {
+ /* allocate memory for the BDL for each stream */
+ err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
+ BDL_SIZE, &s->bdl);
+ num_streams++;
+ if (err < 0)
+ return -ENOMEM;
+ }
+
+ if (WARN_ON(!num_streams))
+ return -EINVAL;
+ /* allocate memory for the position buffer */
+ err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
+ num_streams * 8, &bus->posbuf);
+ if (err < 0)
+ return -ENOMEM;
+ list_for_each_entry(s, &bus->stream_list, list)
+ s->posbuf = (__le32 *)(bus->posbuf.area + s->index * 8);
+
+ /* single page (at least 4096 bytes) must suffice for both ringbuffes */
+ return bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
+ PAGE_SIZE, &bus->rb);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_alloc_stream_pages);
+
+/**
+ * snd_hdac_bus_free_stream_pages - release BDL and other buffers
+ * @bus: HD-audio core bus
+ */
+void snd_hdac_bus_free_stream_pages(struct hdac_bus *bus)
+{
+ struct hdac_stream *s;
+
+ list_for_each_entry(s, &bus->stream_list, list) {
+ if (s->bdl.area)
+ bus->io_ops->dma_free_pages(bus, &s->bdl);
+ }
+
+ if (bus->rb.area)
+ bus->io_ops->dma_free_pages(bus, &bus->rb);
+ if (bus->posbuf.area)
+ bus->io_ops->dma_free_pages(bus, &bus->posbuf);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_free_stream_pages);