1 files changed, 662 insertions, 0 deletions

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
new file mode 100644
index 000000000..9a60bfdb3
--- /dev/null
+++ b/sound/hda/hdac_controller.c
@@ -0,0 +1,662 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+#include "local.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);
+	/* Accept unsolicited responses */
+	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, AZX_GCTL_UNSOL);
+	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.
+ * The caller needs bus->reg_lock spinlock before calling this.
+ */
+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]--;
+			if (!bus->rirb.cmds[addr] &&
+			    waitqueue_active(&bus->rirb_wq))
+				wake_up(&bus->rirb_wq);
+		} 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;
+	wait_queue_entry_t wait;
+	bool warned = false;
+
+	init_wait_entry(&wait, 0);
+	timeout = jiffies + msecs_to_jiffies(1000);
+
+	for (loopcounter = 0;; loopcounter++) {
+		spin_lock_irq(&bus->reg_lock);
+		if (!bus->polling_mode)
+			prepare_to_wait(&bus->rirb_wq, &wait,
+					TASK_UNINTERRUPTIBLE);
+		if (bus->polling_mode)
+			snd_hdac_bus_update_rirb(bus);
+		if (!bus->rirb.cmds[addr]) {
+			if (res)
+				*res = bus->rirb.res[addr]; /* the last value */
+			if (!bus->polling_mode)
+				finish_wait(&bus->rirb_wq, &wait);
+			spin_unlock_irq(&bus->reg_lock);
+			return 0;
+		}
+		spin_unlock_irq(&bus->reg_lock);
+		if (time_after(jiffies, timeout))
+			break;
+#define LOOP_COUNT_MAX	3000
+		if (!bus->polling_mode) {
+			schedule_timeout(msecs_to_jiffies(2));
+		} else if (bus->needs_damn_long_delay ||
+			   loopcounter > LOOP_COUNT_MAX) {
+			if (loopcounter > LOOP_COUNT_MAX && !warned) {
+				dev_dbg_ratelimited(bus->dev,
+						    "too slow response, last cmd=%#08x\n",
+						    bus->last_cmd[addr]);
+				warned = true;
+			}
+			msleep(2); /* temporary workaround */
+		} else {
+			udelay(10);
+			cond_resched();
+		}
+	}
+
+	if (!bus->polling_mode)
+		finish_wait(&bus->rirb_wq, &wait);
+
+	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, AZX_GCTL_RESET, 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;
+	}
+
+	/* 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,
+			      AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN,
+			      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 & disable controller CIE and GIE */
+	snd_hdac_chip_writel(bus, INTCTL, 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
+ * @ack: 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 dma_type = bus->dma_type ? bus->dma_type : SNDRV_DMA_TYPE_DEV;
+	int err;
+
+	list_for_each_entry(s, &bus->stream_list, list) {
+		/* allocate memory for the BDL for each stream */
+		err = snd_dma_alloc_pages(dma_type, bus->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 = snd_dma_alloc_pages(dma_type, bus->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 snd_dma_alloc_pages(dma_type, bus->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)
+			snd_dma_free_pages(&s->bdl);
+	}
+
+	if (bus->rb.area)
+		snd_dma_free_pages(&bus->rb);
+	if (bus->posbuf.area)
+		snd_dma_free_pages(&bus->posbuf);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_free_stream_pages);
+
+/**
+ * snd_hdac_bus_link_power - power up/down codec link
+ * @codec: HD-audio device
+ * @enable: whether to power-up the link
+ */
+void snd_hdac_bus_link_power(struct hdac_device *codec, bool enable)
+{
+	if (enable)
+		set_bit(codec->addr, &codec->bus->codec_powered);
+	else
+		clear_bit(codec->addr, &codec->bus->codec_powered);
+}
+EXPORT_SYMBOL_GPL(snd_hdac_bus_link_power);