sound/hda/hdac_controller.c - kernel/msm-5.4 - Gitiles

 // 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>

 /* 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.
  */
 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->polling_mode)
 			snd_hdac_bus_update_rirb(bus);
 		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, 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 */
 	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 */
 	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);
	// 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>

	/* 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.
	*/
	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->polling_mode)
	snd_hdac_bus_update_rirb(bus);
	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, 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 */
	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 */
	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);