Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 1437 insertions, 0 deletions

diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
new file mode 100644
index 000000000..c1f62e91b
--- /dev/null
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -0,0 +1,1437 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * u_audio.c -- interface to USB gadget "ALSA sound card" utilities
+ *
+ * Copyright (C) 2016
+ * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
+ *
+ * Sound card implementation was cut-and-pasted with changes
+ * from f_uac2.c and has:
+ *    Copyright (C) 2011
+ *    Yadwinder Singh (yadi.brar01@gmail.com)
+ *    Jaswinder Singh (jaswinder.singh@linaro.org)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+#include <linux/usb/audio.h>
+
+#include "u_audio.h"
+
+#define BUFF_SIZE_MAX	(PAGE_SIZE * 16)
+#define PRD_SIZE_MAX	PAGE_SIZE
+#define MIN_PERIODS	4
+
+enum {
+	UAC_FBACK_CTRL,
+	UAC_P_PITCH_CTRL,
+	UAC_MUTE_CTRL,
+	UAC_VOLUME_CTRL,
+	UAC_RATE_CTRL,
+};
+
+/* Runtime data params for one stream */
+struct uac_rtd_params {
+	struct snd_uac_chip *uac; /* parent chip */
+	bool ep_enabled; /* if the ep is enabled */
+
+	struct snd_pcm_substream *ss;
+
+	/* Ring buffer */
+	ssize_t hw_ptr;
+
+	void *rbuf;
+
+	unsigned int pitch;	/* Stream pitch ratio to 1000000 */
+	unsigned int max_psize;	/* MaxPacketSize of endpoint */
+
+	struct usb_request **reqs;
+
+	struct usb_request *req_fback; /* Feedback endpoint request */
+	bool fb_ep_enabled; /* if the ep is enabled */
+
+  /* Volume/Mute controls and their state */
+  int fu_id; /* Feature Unit ID */
+  struct snd_kcontrol *snd_kctl_volume;
+  struct snd_kcontrol *snd_kctl_mute;
+  s16 volume_min, volume_max, volume_res;
+  s16 volume;
+  int mute;
+
+	struct snd_kcontrol *snd_kctl_rate; /* read-only current rate */
+	int srate; /* selected samplerate */
+	int active; /* playback/capture running */
+
+  spinlock_t lock; /* lock for control transfers */
+
+};
+
+struct snd_uac_chip {
+	struct g_audio *audio_dev;
+
+	struct uac_rtd_params p_prm;
+	struct uac_rtd_params c_prm;
+
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+
+	/* pre-calculated values for playback iso completion */
+	unsigned long long p_residue_mil;
+	unsigned int p_interval;
+	unsigned int p_framesize;
+};
+
+static const struct snd_pcm_hardware uac_pcm_hardware = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER
+		 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
+		 | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
+	.rates = SNDRV_PCM_RATE_CONTINUOUS,
+	.periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX,
+	.buffer_bytes_max = BUFF_SIZE_MAX,
+	.period_bytes_max = PRD_SIZE_MAX,
+	.periods_min = MIN_PERIODS,
+};
+
+static void u_audio_set_fback_frequency(enum usb_device_speed speed,
+					struct usb_ep *out_ep,
+					unsigned long long freq,
+					unsigned int pitch,
+					void *buf)
+{
+	u32 ff = 0;
+	const struct usb_endpoint_descriptor *ep_desc;
+
+	/*
+	 * Because the pitch base is 1000000, the final divider here
+	 * will be 1000 * 1000000 = 1953125 << 9
+	 *
+	 * Instead of dealing with big numbers lets fold this 9 left shift
+	 */
+
+	if (speed == USB_SPEED_FULL) {
+		/*
+		 * Full-speed feedback endpoints report frequency
+		 * in samples/frame
+		 * Format is encoded in Q10.10 left-justified in the 24 bits,
+		 * so that it has a Q10.14 format.
+		 *
+		 * ff = (freq << 14) / 1000
+		 */
+		freq <<= 5;
+	} else {
+		/*
+		 * High-speed feedback endpoints report frequency
+		 * in samples/microframe.
+		 * Format is encoded in Q12.13 fitted into four bytes so that
+		 * the binary point is located between the second and the third
+		 * byte fromat (that is Q16.16)
+		 *
+		 * ff = (freq << 16) / 8000
+		 *
+		 * Win10 and OSX UAC2 drivers require number of samples per packet
+		 * in order to honor the feedback value.
+		 * Linux snd-usb-audio detects the applied bit-shift automatically.
+		 */
+		ep_desc = out_ep->desc;
+		freq <<= 4 + (ep_desc->bInterval - 1);
+	}
+
+	ff = DIV_ROUND_CLOSEST_ULL((freq * pitch), 1953125);
+
+	*(__le32 *)buf = cpu_to_le32(ff);
+}
+
+static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	unsigned int pending;
+	unsigned int hw_ptr;
+	int status = req->status;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	struct uac_rtd_params *prm = req->context;
+	struct snd_uac_chip *uac = prm->uac;
+	unsigned int frames, p_pktsize;
+	unsigned long long pitched_rate_mil, p_pktsize_residue_mil,
+			residue_frames_mil, div_result;
+
+	/* i/f shutting down */
+	if (!prm->ep_enabled) {
+		usb_ep_free_request(ep, req);
+		return;
+	}
+
+	if (req->status == -ESHUTDOWN)
+		return;
+
+	/*
+	 * We can't really do much about bad xfers.
+	 * Afterall, the ISOCH xfers could fail legitimately.
+	 */
+	if (status)
+		pr_debug("%s: iso_complete status(%d) %d/%d\n",
+			__func__, status, req->actual, req->length);
+
+	substream = prm->ss;
+
+	/* Do nothing if ALSA isn't active */
+	if (!substream)
+		goto exit;
+
+	snd_pcm_stream_lock(substream);
+
+	runtime = substream->runtime;
+	if (!runtime || !snd_pcm_running(substream)) {
+		snd_pcm_stream_unlock(substream);
+		goto exit;
+	}
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		/*
+		 * For each IN packet, take the quotient of the current data
+		 * rate and the endpoint's interval as the base packet size.
+		 * If there is a residue from this division, add it to the
+		 * residue accumulator.
+		 */
+		unsigned long long p_interval_mil = uac->p_interval * 1000000ULL;
+
+		pitched_rate_mil = (unsigned long long) prm->srate * prm->pitch;
+		div_result = pitched_rate_mil;
+		do_div(div_result, uac->p_interval);
+		do_div(div_result, 1000000);
+		frames = (unsigned int) div_result;
+
+		pr_debug("p_srate %d, pitch %d, interval_mil %llu, frames %d\n",
+				prm->srate, prm->pitch, p_interval_mil, frames);
+
+		p_pktsize = min_t(unsigned int,
+					uac->p_framesize * frames,
+					ep->maxpacket);
+
+		if (p_pktsize < ep->maxpacket) {
+			residue_frames_mil = pitched_rate_mil - frames * p_interval_mil;
+			p_pktsize_residue_mil = uac->p_framesize * residue_frames_mil;
+		} else
+			p_pktsize_residue_mil = 0;
+
+		req->length = p_pktsize;
+		uac->p_residue_mil += p_pktsize_residue_mil;
+
+		/*
+		 * Whenever there are more bytes in the accumulator p_residue_mil than we
+		 * need to add one more sample frame, increase this packet's
+		 * size and decrease the accumulator.
+		 */
+		div_result = uac->p_residue_mil;
+		do_div(div_result, uac->p_interval);
+		do_div(div_result, 1000000);
+		if ((unsigned int) div_result >= uac->p_framesize) {
+			req->length += uac->p_framesize;
+			uac->p_residue_mil -= uac->p_framesize * p_interval_mil;
+			pr_debug("increased req length to %d\n", req->length);
+		}
+		pr_debug("remains uac->p_residue_mil %llu\n", uac->p_residue_mil);
+
+		req->actual = req->length;
+	}
+
+	hw_ptr = prm->hw_ptr;
+
+	/* Pack USB load in ALSA ring buffer */
+	pending = runtime->dma_bytes - hw_ptr;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		if (unlikely(pending < req->actual)) {
+			memcpy(req->buf, runtime->dma_area + hw_ptr, pending);
+			memcpy(req->buf + pending, runtime->dma_area,
+			       req->actual - pending);
+		} else {
+			memcpy(req->buf, runtime->dma_area + hw_ptr,
+			       req->actual);
+		}
+	} else {
+		if (unlikely(pending < req->actual)) {
+			memcpy(runtime->dma_area + hw_ptr, req->buf, pending);
+			memcpy(runtime->dma_area, req->buf + pending,
+			       req->actual - pending);
+		} else {
+			memcpy(runtime->dma_area + hw_ptr, req->buf,
+			       req->actual);
+		}
+	}
+
+	/* update hw_ptr after data is copied to memory */
+	prm->hw_ptr = (hw_ptr + req->actual) % runtime->dma_bytes;
+	hw_ptr = prm->hw_ptr;
+	snd_pcm_stream_unlock(substream);
+
+	if ((hw_ptr % snd_pcm_lib_period_bytes(substream)) < req->actual)
+		snd_pcm_period_elapsed(substream);
+
+exit:
+	if (usb_ep_queue(ep, req, GFP_ATOMIC))
+		dev_err(uac->card->dev, "%d Error!\n", __LINE__);
+}
+
+static void u_audio_iso_fback_complete(struct usb_ep *ep,
+				       struct usb_request *req)
+{
+	struct uac_rtd_params *prm = req->context;
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	int status = req->status;
+
+	/* i/f shutting down */
+	if (!prm->fb_ep_enabled) {
+		kfree(req->buf);
+		usb_ep_free_request(ep, req);
+		return;
+	}
+
+	if (req->status == -ESHUTDOWN)
+		return;
+
+	/*
+	 * We can't really do much about bad xfers.
+	 * Afterall, the ISOCH xfers could fail legitimately.
+	 */
+	if (status)
+		pr_debug("%s: iso_complete status(%d) %d/%d\n",
+			__func__, status, req->actual, req->length);
+
+	u_audio_set_fback_frequency(audio_dev->gadget->speed, audio_dev->out_ep,
+				    prm->srate, prm->pitch,
+				    req->buf);
+
+	if (usb_ep_queue(ep, req, GFP_ATOMIC))
+		dev_err(uac->card->dev, "%d Error!\n", __LINE__);
+}
+
+static int uac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
+	struct uac_rtd_params *prm;
+	struct g_audio *audio_dev;
+	struct uac_params *params;
+	int err = 0;
+
+	audio_dev = uac->audio_dev;
+	params = &audio_dev->params;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	/* Reset */
+	prm->hw_ptr = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		prm->ss = substream;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		prm->ss = NULL;
+		break;
+	default:
+		err = -EINVAL;
+	}
+
+	/* Clear buffer after Play stops */
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss)
+		memset(prm->rbuf, 0, prm->max_psize * params->req_number);
+
+	return err;
+}
+
+static snd_pcm_uframes_t uac_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
+	struct uac_rtd_params *prm;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	return bytes_to_frames(substream->runtime, prm->hw_ptr);
+}
+
+static u64 uac_ssize_to_fmt(int ssize)
+{
+	u64 ret;
+
+	switch (ssize) {
+	case 3:
+		ret = SNDRV_PCM_FMTBIT_S24_3LE;
+		break;
+	case 4:
+		ret = SNDRV_PCM_FMTBIT_S32_LE;
+		break;
+	default:
+		ret = SNDRV_PCM_FMTBIT_S16_LE;
+		break;
+	}
+
+	return ret;
+}
+
+static int uac_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct g_audio *audio_dev;
+	struct uac_params *params;
+	struct uac_rtd_params *prm;
+	int p_ssize, c_ssize;
+	int p_chmask, c_chmask;
+
+	audio_dev = uac->audio_dev;
+	params = &audio_dev->params;
+	p_ssize = params->p_ssize;
+	c_ssize = params->c_ssize;
+	p_chmask = params->p_chmask;
+	c_chmask = params->c_chmask;
+	uac->p_residue_mil = 0;
+
+	runtime->hw = uac_pcm_hardware;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		runtime->hw.formats = uac_ssize_to_fmt(p_ssize);
+		runtime->hw.channels_min = num_channels(p_chmask);
+		prm = &uac->p_prm;
+	} else {
+		runtime->hw.formats = uac_ssize_to_fmt(c_ssize);
+		runtime->hw.channels_min = num_channels(c_chmask);
+		prm = &uac->c_prm;
+	}
+
+	runtime->hw.period_bytes_min = 2 * prm->max_psize
+					/ runtime->hw.periods_min;
+	runtime->hw.rate_min = prm->srate;
+	runtime->hw.rate_max = runtime->hw.rate_min;
+	runtime->hw.channels_max = runtime->hw.channels_min;
+
+	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+
+	return 0;
+}
+
+/* ALSA cries without these function pointers */
+static int uac_pcm_null(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+static const struct snd_pcm_ops uac_pcm_ops = {
+	.open = uac_pcm_open,
+	.close = uac_pcm_null,
+	.trigger = uac_pcm_trigger,
+	.pointer = uac_pcm_pointer,
+	.prepare = uac_pcm_null,
+};
+
+static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep)
+{
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev;
+	struct uac_params *params;
+	int i;
+
+	if (!prm->ep_enabled)
+		return;
+
+	audio_dev = uac->audio_dev;
+	params = &audio_dev->params;
+
+	for (i = 0; i < params->req_number; i++) {
+		if (prm->reqs[i]) {
+			if (usb_ep_dequeue(ep, prm->reqs[i]))
+				usb_ep_free_request(ep, prm->reqs[i]);
+			/*
+			 * If usb_ep_dequeue() cannot successfully dequeue the
+			 * request, the request will be freed by the completion
+			 * callback.
+			 */
+
+			prm->reqs[i] = NULL;
+		}
+	}
+
+	prm->ep_enabled = false;
+
+	if (usb_ep_disable(ep))
+		dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
+}
+
+static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep)
+{
+	struct snd_uac_chip *uac = prm->uac;
+
+	if (!prm->fb_ep_enabled)
+		return;
+
+	if (prm->req_fback) {
+		if (usb_ep_dequeue(ep, prm->req_fback)) {
+			kfree(prm->req_fback->buf);
+			usb_ep_free_request(ep, prm->req_fback);
+		}
+		prm->req_fback = NULL;
+	}
+
+	prm->fb_ep_enabled = false;
+
+	if (usb_ep_disable(ep))
+		dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
+}
+
+static void set_active(struct uac_rtd_params *prm, bool active)
+{
+	// notifying through the Rate ctrl
+	struct snd_kcontrol *kctl = prm->snd_kctl_rate;
+	unsigned long flags;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	if (prm->active != active) {
+		prm->active = active;
+		snd_ctl_notify(prm->uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
+				&kctl->id);
+	}
+	spin_unlock_irqrestore(&prm->lock, flags);
+}
+
+int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate)
+{
+	struct uac_params *params = &audio_dev->params;
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	int i;
+	unsigned long flags;
+
+	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
+	prm = &uac->c_prm;
+	for (i = 0; i < UAC_MAX_RATES; i++) {
+		if (params->c_srates[i] == srate) {
+			spin_lock_irqsave(&prm->lock, flags);
+			prm->srate = srate;
+			spin_unlock_irqrestore(&prm->lock, flags);
+			return 0;
+		}
+		if (params->c_srates[i] == 0)
+			break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_capture_srate);
+
+int u_audio_get_capture_srate(struct g_audio *audio_dev, u32 *val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+
+	prm = &uac->c_prm;
+	spin_lock_irqsave(&prm->lock, flags);
+	*val = prm->srate;
+	spin_unlock_irqrestore(&prm->lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_capture_srate);
+
+int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate)
+{
+	struct uac_params *params = &audio_dev->params;
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	int i;
+	unsigned long flags;
+
+	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
+	prm = &uac->p_prm;
+	for (i = 0; i < UAC_MAX_RATES; i++) {
+		if (params->p_srates[i] == srate) {
+			spin_lock_irqsave(&prm->lock, flags);
+			prm->srate = srate;
+			spin_unlock_irqrestore(&prm->lock, flags);
+			return 0;
+		}
+		if (params->p_srates[i] == 0)
+			break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_playback_srate);
+
+int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+
+	prm = &uac->p_prm;
+	spin_lock_irqsave(&prm->lock, flags);
+	*val = prm->srate;
+	spin_unlock_irqrestore(&prm->lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_playback_srate);
+
+int u_audio_start_capture(struct g_audio *audio_dev)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct usb_gadget *gadget = audio_dev->gadget;
+	struct device *dev = &gadget->dev;
+	struct usb_request *req, *req_fback;
+	struct usb_ep *ep, *ep_fback;
+	struct uac_rtd_params *prm;
+	struct uac_params *params = &audio_dev->params;
+	int req_len, i;
+
+	prm = &uac->c_prm;
+	dev_dbg(dev, "start capture with rate %d\n", prm->srate);
+	ep = audio_dev->out_ep;
+	config_ep_by_speed(gadget, &audio_dev->func, ep);
+	req_len = ep->maxpacket;
+
+	prm->ep_enabled = true;
+	usb_ep_enable(ep);
+
+	for (i = 0; i < params->req_number; i++) {
+		if (!prm->reqs[i]) {
+			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
+			if (req == NULL)
+				return -ENOMEM;
+
+			prm->reqs[i] = req;
+
+			req->zero = 0;
+			req->context = prm;
+			req->length = req_len;
+			req->complete = u_audio_iso_complete;
+			req->buf = prm->rbuf + i * ep->maxpacket;
+		}
+
+		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
+			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+	}
+
+	set_active(&uac->c_prm, true);
+
+	ep_fback = audio_dev->in_ep_fback;
+	if (!ep_fback)
+		return 0;
+
+	/* Setup feedback endpoint */
+	config_ep_by_speed(gadget, &audio_dev->func, ep_fback);
+	prm->fb_ep_enabled = true;
+	usb_ep_enable(ep_fback);
+	req_len = ep_fback->maxpacket;
+
+	req_fback = usb_ep_alloc_request(ep_fback, GFP_ATOMIC);
+	if (req_fback == NULL)
+		return -ENOMEM;
+
+	prm->req_fback = req_fback;
+	req_fback->zero = 0;
+	req_fback->context = prm;
+	req_fback->length = req_len;
+	req_fback->complete = u_audio_iso_fback_complete;
+
+	req_fback->buf = kzalloc(req_len, GFP_ATOMIC);
+	if (!req_fback->buf)
+		return -ENOMEM;
+
+	/*
+	 * Configure the feedback endpoint's reported frequency.
+	 * Always start with original frequency since its deviation can't
+	 * be meauserd at start of playback
+	 */
+	prm->pitch = 1000000;
+	u_audio_set_fback_frequency(audio_dev->gadget->speed, ep,
+				    prm->srate, prm->pitch,
+				    req_fback->buf);
+
+	if (usb_ep_queue(ep_fback, req_fback, GFP_ATOMIC))
+		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_start_capture);
+
+void u_audio_stop_capture(struct g_audio *audio_dev)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+
+	set_active(&uac->c_prm, false);
+	if (audio_dev->in_ep_fback)
+		free_ep_fback(&uac->c_prm, audio_dev->in_ep_fback);
+	free_ep(&uac->c_prm, audio_dev->out_ep);
+}
+EXPORT_SYMBOL_GPL(u_audio_stop_capture);
+
+int u_audio_start_playback(struct g_audio *audio_dev)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct usb_gadget *gadget = audio_dev->gadget;
+	struct device *dev = &gadget->dev;
+	struct usb_request *req;
+	struct usb_ep *ep;
+	struct uac_rtd_params *prm;
+	struct uac_params *params = &audio_dev->params;
+	unsigned int factor;
+	const struct usb_endpoint_descriptor *ep_desc;
+	int req_len, i;
+	unsigned int p_pktsize;
+
+	prm = &uac->p_prm;
+	dev_dbg(dev, "start playback with rate %d\n", prm->srate);
+	ep = audio_dev->in_ep;
+	config_ep_by_speed(gadget, &audio_dev->func, ep);
+
+	ep_desc = ep->desc;
+	/*
+	 * Always start with original frequency
+	 */
+	prm->pitch = 1000000;
+
+	/* pre-calculate the playback endpoint's interval */
+	if (gadget->speed == USB_SPEED_FULL)
+		factor = 1000;
+	else
+		factor = 8000;
+
+	/* pre-compute some values for iso_complete() */
+	uac->p_framesize = params->p_ssize *
+			    num_channels(params->p_chmask);
+	uac->p_interval = factor / (1 << (ep_desc->bInterval - 1));
+	p_pktsize = min_t(unsigned int,
+				uac->p_framesize *
+					(prm->srate / uac->p_interval),
+				ep->maxpacket);
+
+	req_len = p_pktsize;
+	uac->p_residue_mil = 0;
+
+	prm->ep_enabled = true;
+	usb_ep_enable(ep);
+
+	for (i = 0; i < params->req_number; i++) {
+		if (!prm->reqs[i]) {
+			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
+			if (req == NULL)
+				return -ENOMEM;
+
+			prm->reqs[i] = req;
+
+			req->zero = 0;
+			req->context = prm;
+			req->length = req_len;
+			req->complete = u_audio_iso_complete;
+			req->buf = prm->rbuf + i * ep->maxpacket;
+		}
+
+		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
+			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
+	}
+
+	set_active(&uac->p_prm, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_start_playback);
+
+void u_audio_stop_playback(struct g_audio *audio_dev)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+
+	set_active(&uac->p_prm, false);
+	free_ep(&uac->p_prm, audio_dev->in_ep);
+}
+EXPORT_SYMBOL_GPL(u_audio_stop_playback);
+
+void u_audio_suspend(struct g_audio *audio_dev)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+
+	set_active(&uac->p_prm, false);
+	set_active(&uac->c_prm, false);
+}
+EXPORT_SYMBOL_GPL(u_audio_suspend);
+
+int u_audio_get_volume(struct g_audio *audio_dev, int playback, s16 *val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+
+	if (playback)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	*val = prm->volume;
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_volume);
+
+int u_audio_set_volume(struct g_audio *audio_dev, int playback, s16 val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+	int change = 0;
+
+	if (playback)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	val = clamp(val, prm->volume_min, prm->volume_max);
+	if (prm->volume != val) {
+		prm->volume = val;
+		change = 1;
+	}
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	if (change)
+		snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
+				&prm->snd_kctl_volume->id);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_volume);
+
+int u_audio_get_mute(struct g_audio *audio_dev, int playback, int *val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+
+	if (playback)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	*val = prm->mute;
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_mute);
+
+int u_audio_set_mute(struct g_audio *audio_dev, int playback, int val)
+{
+	struct snd_uac_chip *uac = audio_dev->uac;
+	struct uac_rtd_params *prm;
+	unsigned long flags;
+	int change = 0;
+	int mute;
+
+	if (playback)
+		prm = &uac->p_prm;
+	else
+		prm = &uac->c_prm;
+
+	mute = val ? 1 : 0;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	if (prm->mute != mute) {
+		prm->mute = mute;
+		change = 1;
+	}
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	if (change)
+		snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
+			       &prm->snd_kctl_mute->id);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_mute);
+
+
+static int u_audio_pitch_info(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_info *uinfo)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	struct uac_params *params = &audio_dev->params;
+	unsigned int pitch_min, pitch_max;
+
+	pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
+	pitch_max = (1000 + params->fb_max) * 1000;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+	uinfo->value.integer.min = pitch_min;
+	uinfo->value.integer.max = pitch_max;
+	uinfo->value.integer.step = 1;
+	return 0;
+}
+
+static int u_audio_pitch_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+
+	ucontrol->value.integer.value[0] = prm->pitch;
+
+	return 0;
+}
+
+static int u_audio_pitch_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	struct uac_params *params = &audio_dev->params;
+	unsigned int val;
+	unsigned int pitch_min, pitch_max;
+	int change = 0;
+
+	pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
+	pitch_max = (1000 + params->fb_max) * 1000;
+
+	val = ucontrol->value.integer.value[0];
+
+	if (val < pitch_min)
+		val = pitch_min;
+	if (val > pitch_max)
+		val = pitch_max;
+
+	if (prm->pitch != val) {
+		prm->pitch = val;
+		change = 1;
+	}
+
+	return change;
+}
+
+static int u_audio_mute_info(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	uinfo->value.integer.step = 1;
+
+	return 0;
+}
+
+static int u_audio_mute_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	unsigned long flags;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	ucontrol->value.integer.value[0] = !prm->mute;
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	return 0;
+}
+
+static int u_audio_mute_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	unsigned int val;
+	unsigned long flags;
+	int change = 0;
+
+	val = !ucontrol->value.integer.value[0];
+
+	spin_lock_irqsave(&prm->lock, flags);
+	if (val != prm->mute) {
+		prm->mute = val;
+		change = 1;
+	}
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	if (change && audio_dev->notify)
+		audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_MUTE);
+
+	return change;
+}
+
+/*
+ * TLV callback for mixer volume controls
+ */
+static int u_audio_volume_tlv(struct snd_kcontrol *kcontrol, int op_flag,
+			 unsigned int size, unsigned int __user *_tlv)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
+
+	if (size < sizeof(scale))
+		return -ENOMEM;
+
+	/* UAC volume resolution is 1/256 dB, TLV is 1/100 dB */
+	scale[2] = (prm->volume_min * 100) / 256;
+	scale[3] = (prm->volume_max * 100) / 256;
+	if (copy_to_user(_tlv, scale, sizeof(scale)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int u_audio_volume_info(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_info *uinfo)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max =
+		(prm->volume_max - prm->volume_min + prm->volume_res - 1)
+		/ prm->volume_res;
+	uinfo->value.integer.step = 1;
+
+	return 0;
+}
+
+static int u_audio_volume_get(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	unsigned long flags;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	ucontrol->value.integer.value[0] =
+			(prm->volume - prm->volume_min) / prm->volume_res;
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	return 0;
+}
+
+static int u_audio_volume_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	unsigned int val;
+	s16 volume;
+	unsigned long flags;
+	int change = 0;
+
+	val = ucontrol->value.integer.value[0];
+
+	spin_lock_irqsave(&prm->lock, flags);
+	volume = (val * prm->volume_res) + prm->volume_min;
+	volume = clamp(volume, prm->volume_min, prm->volume_max);
+	if (volume != prm->volume) {
+		prm->volume = volume;
+		change = 1;
+	}
+	spin_unlock_irqrestore(&prm->lock, flags);
+
+	if (change && audio_dev->notify)
+		audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_VOLUME);
+
+	return change;
+}
+
+static int get_max_srate(const int *srates)
+{
+	int i, max_srate = 0;
+
+	for (i = 0; i < UAC_MAX_RATES; i++) {
+		if (srates[i] == 0)
+			break;
+		if (srates[i] > max_srate)
+			max_srate = srates[i];
+	}
+	return max_srate;
+}
+
+static int get_min_srate(const int *srates)
+{
+	int i, min_srate = INT_MAX;
+
+	for (i = 0; i < UAC_MAX_RATES; i++) {
+		if (srates[i] == 0)
+			break;
+		if (srates[i] < min_srate)
+			min_srate = srates[i];
+	}
+	return min_srate;
+}
+
+static int u_audio_rate_info(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_info *uinfo)
+{
+	const int *srates;
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	struct snd_uac_chip *uac = prm->uac;
+	struct g_audio *audio_dev = uac->audio_dev;
+	struct uac_params *params = &audio_dev->params;
+
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+
+	if (prm == &uac->c_prm)
+		srates = params->c_srates;
+	else
+		srates = params->p_srates;
+	uinfo->value.integer.min = get_min_srate(srates);
+	uinfo->value.integer.max = get_max_srate(srates);
+	return 0;
+}
+
+static int u_audio_rate_get(struct snd_kcontrol *kcontrol,
+						 struct snd_ctl_elem_value *ucontrol)
+{
+	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+	unsigned long flags;
+
+	spin_lock_irqsave(&prm->lock, flags);
+	if (prm->active)
+		ucontrol->value.integer.value[0] = prm->srate;
+	else
+		/* not active: reporting zero rate */
+		ucontrol->value.integer.value[0] = 0;
+	spin_unlock_irqrestore(&prm->lock, flags);
+	return 0;
+}
+
+static struct snd_kcontrol_new u_audio_controls[]  = {
+  [UAC_FBACK_CTRL] {
+    .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
+    .name =         "Capture Pitch 1000000",
+    .info =         u_audio_pitch_info,
+    .get =          u_audio_pitch_get,
+    .put =          u_audio_pitch_put,
+  },
+	[UAC_P_PITCH_CTRL] {
+		.iface =        SNDRV_CTL_ELEM_IFACE_PCM,
+		.name =         "Playback Pitch 1000000",
+		.info =         u_audio_pitch_info,
+		.get =          u_audio_pitch_get,
+		.put =          u_audio_pitch_put,
+	},
+  [UAC_MUTE_CTRL] {
+		.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name =		"", /* will be filled later */
+		.info =		u_audio_mute_info,
+		.get =		u_audio_mute_get,
+		.put =		u_audio_mute_put,
+	},
+	[UAC_VOLUME_CTRL] {
+		.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name =		"", /* will be filled later */
+		.info =		u_audio_volume_info,
+		.get =		u_audio_volume_get,
+		.put =		u_audio_volume_put,
+	},
+	[UAC_RATE_CTRL] {
+		.iface =	SNDRV_CTL_ELEM_IFACE_PCM,
+		.name =		"", /* will be filled later */
+		.access =	SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
+		.info =		u_audio_rate_info,
+		.get =		u_audio_rate_get,
+	},
+};
+
+int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
+					const char *card_name)
+{
+	struct snd_uac_chip *uac;
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	struct snd_kcontrol *kctl;
+	struct uac_params *params;
+	int p_chmask, c_chmask;
+	int i, err;
+
+	if (!g_audio)
+		return -EINVAL;
+
+	uac = kzalloc(sizeof(*uac), GFP_KERNEL);
+	if (!uac)
+		return -ENOMEM;
+	g_audio->uac = uac;
+	uac->audio_dev = g_audio;
+
+	params = &g_audio->params;
+	p_chmask = params->p_chmask;
+	c_chmask = params->c_chmask;
+
+	if (c_chmask) {
+		struct uac_rtd_params *prm = &uac->c_prm;
+
+		spin_lock_init(&prm->lock);
+		uac->c_prm.uac = uac;
+		prm->max_psize = g_audio->out_ep_maxpsize;
+		prm->srate = params->c_srates[0];
+
+		prm->reqs = kcalloc(params->req_number,
+				    sizeof(struct usb_request *),
+				    GFP_KERNEL);
+		if (!prm->reqs) {
+			err = -ENOMEM;
+			goto fail;
+		}
+
+		prm->rbuf = kcalloc(params->req_number, prm->max_psize,
+				GFP_KERNEL);
+		if (!prm->rbuf) {
+			prm->max_psize = 0;
+			err = -ENOMEM;
+			goto fail;
+		}
+	}
+
+	if (p_chmask) {
+		struct uac_rtd_params *prm = &uac->p_prm;
+
+		spin_lock_init(&prm->lock);
+		uac->p_prm.uac = uac;
+		prm->max_psize = g_audio->in_ep_maxpsize;
+		prm->srate = params->p_srates[0];
+
+		prm->reqs = kcalloc(params->req_number,
+				    sizeof(struct usb_request *),
+				    GFP_KERNEL);
+		if (!prm->reqs) {
+			err = -ENOMEM;
+			goto fail;
+		}
+
+		prm->rbuf = kcalloc(params->req_number, prm->max_psize,
+				GFP_KERNEL);
+		if (!prm->rbuf) {
+			prm->max_psize = 0;
+			err = -ENOMEM;
+			goto fail;
+		}
+	}
+
+	/* Choose any slot, with no id */
+	err = snd_card_new(&g_audio->gadget->dev,
+			-1, NULL, THIS_MODULE, 0, &card);
+	if (err < 0)
+		goto fail;
+
+	uac->card = card;
+
+	/*
+	 * Create first PCM device
+	 * Create a substream only for non-zero channel streams
+	 */
+	err = snd_pcm_new(uac->card, pcm_name, 0,
+			       p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
+	if (err < 0)
+		goto snd_fail;
+
+	strscpy(pcm->name, pcm_name, sizeof(pcm->name));
+	pcm->private_data = uac;
+	uac->pcm = pcm;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac_pcm_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac_pcm_ops);
+
+	/*
+	 * Create mixer and controls
+	 * Create only if it's required on USB side
+	 */
+	if ((c_chmask && g_audio->in_ep_fback)
+			|| (p_chmask && params->p_fu.id)
+			|| (c_chmask && params->c_fu.id))
+		strscpy(card->mixername, card_name, sizeof(card->driver));
+
+	if (c_chmask && g_audio->in_ep_fback) {
+		kctl = snd_ctl_new1(&u_audio_controls[UAC_FBACK_CTRL],
+				    &uac->c_prm);
+		if (!kctl) {
+			err = -ENOMEM;
+			goto snd_fail;
+		}
+
+		kctl->id.device = pcm->device;
+		kctl->id.subdevice = 0;
+
+		err = snd_ctl_add(card, kctl);
+		if (err < 0)
+			goto snd_fail;
+	}
+
+	if (p_chmask) {
+		kctl = snd_ctl_new1(&u_audio_controls[UAC_P_PITCH_CTRL],
+				    &uac->p_prm);
+		if (!kctl) {
+			err = -ENOMEM;
+			goto snd_fail;
+		}
+
+		kctl->id.device = pcm->device;
+		kctl->id.subdevice = 0;
+
+		err = snd_ctl_add(card, kctl);
+		if (err < 0)
+			goto snd_fail;
+	}
+
+	for (i = 0; i <= SNDRV_PCM_STREAM_LAST; i++) {
+		struct uac_rtd_params *prm;
+		struct uac_fu_params *fu;
+		char ctrl_name[24];
+		char *direction;
+
+		if (!pcm->streams[i].substream_count)
+			continue;
+
+		if (i == SNDRV_PCM_STREAM_PLAYBACK) {
+			prm = &uac->p_prm;
+			fu = &params->p_fu;
+			direction = "Playback";
+		} else {
+			prm = &uac->c_prm;
+			fu = &params->c_fu;
+			direction = "Capture";
+		}
+
+		prm->fu_id = fu->id;
+
+		if (fu->mute_present) {
+			snprintf(ctrl_name, sizeof(ctrl_name),
+					"PCM %s Switch", direction);
+
+			u_audio_controls[UAC_MUTE_CTRL].name = ctrl_name;
+
+			kctl = snd_ctl_new1(&u_audio_controls[UAC_MUTE_CTRL],
+					    prm);
+			if (!kctl) {
+				err = -ENOMEM;
+				goto snd_fail;
+			}
+
+			kctl->id.device = pcm->device;
+			kctl->id.subdevice = 0;
+
+			err = snd_ctl_add(card, kctl);
+			if (err < 0)
+				goto snd_fail;
+			prm->snd_kctl_mute = kctl;
+			prm->mute = 0;
+		}
+
+		if (fu->volume_present) {
+			snprintf(ctrl_name, sizeof(ctrl_name),
+					"PCM %s Volume", direction);
+
+			u_audio_controls[UAC_VOLUME_CTRL].name = ctrl_name;
+
+			kctl = snd_ctl_new1(&u_audio_controls[UAC_VOLUME_CTRL],
+					    prm);
+			if (!kctl) {
+				err = -ENOMEM;
+				goto snd_fail;
+			}
+
+			kctl->id.device = pcm->device;
+			kctl->id.subdevice = 0;
+
+
+			kctl->tlv.c = u_audio_volume_tlv;
+			kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+					SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
+
+			err = snd_ctl_add(card, kctl);
+			if (err < 0)
+				goto snd_fail;
+			prm->snd_kctl_volume = kctl;
+			prm->volume = fu->volume_max;
+			prm->volume_max = fu->volume_max;
+			prm->volume_min = fu->volume_min;
+			prm->volume_res = fu->volume_res;
+		}
+
+		/* Add rate control */
+		snprintf(ctrl_name, sizeof(ctrl_name),
+				"%s Rate", direction);
+		u_audio_controls[UAC_RATE_CTRL].name = ctrl_name;
+
+		kctl = snd_ctl_new1(&u_audio_controls[UAC_RATE_CTRL], prm);
+		if (!kctl) {
+			err = -ENOMEM;
+			goto snd_fail;
+		}
+
+		kctl->id.device = pcm->device;
+		kctl->id.subdevice = 0;
+
+		err = snd_ctl_add(card, kctl);
+		if (err < 0)
+			goto snd_fail;
+		prm->snd_kctl_rate = kctl;
+	}
+
+	strscpy(card->driver, card_name, sizeof(card->driver));
+	strscpy(card->shortname, card_name, sizeof(card->shortname));
+	sprintf(card->longname, "%s %i", card_name, card->dev->id);
+
+	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+				       NULL, 0, BUFF_SIZE_MAX);
+
+	err = snd_card_register(card);
+
+	if (!err)
+		return 0;
+
+snd_fail:
+	snd_card_free(card);
+fail:
+	kfree(uac->p_prm.reqs);
+	kfree(uac->c_prm.reqs);
+	kfree(uac->p_prm.rbuf);
+	kfree(uac->c_prm.rbuf);
+	kfree(uac);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(g_audio_setup);
+
+void g_audio_cleanup(struct g_audio *g_audio)
+{
+	struct snd_uac_chip *uac;
+	struct snd_card *card;
+
+	if (!g_audio || !g_audio->uac)
+		return;
+
+	uac = g_audio->uac;
+	card = uac->card;
+	if (card)
+		snd_card_free(card);
+
+	kfree(uac->p_prm.reqs);
+	kfree(uac->c_prm.reqs);
+	kfree(uac->p_prm.rbuf);
+	kfree(uac->c_prm.rbuf);
+	kfree(uac);
+}
+EXPORT_SYMBOL_GPL(g_audio_cleanup);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("USB gadget \"ALSA sound card\" utilities");
+MODULE_AUTHOR("Ruslan Bilovol");