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, 796 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_tis_i2c_cr50.c b/drivers/char/tpm/tpm_tis_i2c_cr50.c
new file mode 100644
index 000000000..77cea5b31
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_i2c_cr50.c
@@ -0,0 +1,796 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 Google Inc.
+ *
+ * Based on Infineon TPM driver by Peter Huewe.
+ *
+ * cr50 is a firmware for H1 secure modules that requires special
+ * handling for the I2C interface.
+ *
+ * - Use an interrupt for transaction status instead of hardcoded delays.
+ * - Must use write+wait+read read protocol.
+ * - All 4 bytes of status register must be read/written at once.
+ * - Burst count max is 63 bytes, and burst count behaves slightly differently
+ *   than other I2C TPMs.
+ * - When reading from FIFO the full burstcnt must be read instead of just
+ *   reading header and determining the remainder.
+ */
+
+#include <linux/acpi.h>
+#include <linux/completion.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "tpm_tis_core.h"
+
+#define TPM_CR50_MAX_BUFSIZE		64
+#define TPM_CR50_TIMEOUT_SHORT_MS	2		/* Short timeout during transactions */
+#define TPM_CR50_TIMEOUT_NOIRQ_MS	20		/* Timeout for TPM ready without IRQ */
+#define TPM_CR50_I2C_DID_VID		0x00281ae0L	/* Device and vendor ID reg value */
+#define TPM_TI50_I2C_DID_VID		0x504a6666L	/* Device and vendor ID reg value */
+#define TPM_CR50_I2C_MAX_RETRIES	3		/* Max retries due to I2C errors */
+#define TPM_CR50_I2C_RETRY_DELAY_LO	55		/* Min usecs between retries on I2C */
+#define TPM_CR50_I2C_RETRY_DELAY_HI	65		/* Max usecs between retries on I2C */
+
+#define TPM_I2C_ACCESS(l)	(0x0000 | ((l) << 4))
+#define TPM_I2C_STS(l)		(0x0001 | ((l) << 4))
+#define TPM_I2C_DATA_FIFO(l)	(0x0005 | ((l) << 4))
+#define TPM_I2C_DID_VID(l)	(0x0006 | ((l) << 4))
+
+/**
+ * struct tpm_i2c_cr50_priv_data - Driver private data.
+ * @irq:	Irq number used for this chip.
+ *		If irq <= 0, then a fixed timeout is used instead of waiting for irq.
+ * @tpm_ready:	Struct used by irq handler to signal R/W readiness.
+ * @buf:	Buffer used for i2c writes, with i2c address prepended to content.
+ *
+ * Private driver struct used by kernel threads and interrupt context.
+ */
+struct tpm_i2c_cr50_priv_data {
+	int irq;
+	struct completion tpm_ready;
+	u8 buf[TPM_CR50_MAX_BUFSIZE];
+};
+
+/**
+ * tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
+ * @dummy:	Unused parameter.
+ * @tpm_info:	TPM chip information.
+ *
+ * The cr50 interrupt handler signals waiting threads that the
+ * interrupt has been asserted. It does not do any interrupt triggered
+ * processing but is instead used to avoid fixed delays.
+ *
+ * Return:
+ *	IRQ_HANDLED signifies irq was handled by this device.
+ */
+static irqreturn_t tpm_cr50_i2c_int_handler(int dummy, void *tpm_info)
+{
+	struct tpm_chip *chip = tpm_info;
+	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
+
+	complete(&priv->tpm_ready);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * tpm_cr50_i2c_wait_tpm_ready() - Wait for tpm to signal ready.
+ * @chip: A TPM chip.
+ *
+ * Wait for completion interrupt if available, otherwise use a fixed
+ * delay for the TPM to be ready.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_wait_tpm_ready(struct tpm_chip *chip)
+{
+	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
+
+	/* Use a safe fixed delay if interrupt is not supported */
+	if (priv->irq <= 0) {
+		msleep(TPM_CR50_TIMEOUT_NOIRQ_MS);
+		return 0;
+	}
+
+	/* Wait for interrupt to indicate TPM is ready to respond */
+	if (!wait_for_completion_timeout(&priv->tpm_ready,
+					 msecs_to_jiffies(chip->timeout_a))) {
+		dev_warn(&chip->dev, "Timeout waiting for TPM ready\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/**
+ * tpm_cr50_i2c_enable_tpm_irq() - Enable TPM irq.
+ * @chip: A TPM chip.
+ */
+static void tpm_cr50_i2c_enable_tpm_irq(struct tpm_chip *chip)
+{
+	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
+
+	if (priv->irq > 0) {
+		reinit_completion(&priv->tpm_ready);
+		enable_irq(priv->irq);
+	}
+}
+
+/**
+ * tpm_cr50_i2c_disable_tpm_irq() - Disable TPM irq.
+ * @chip: A TPM chip.
+ */
+static void tpm_cr50_i2c_disable_tpm_irq(struct tpm_chip *chip)
+{
+	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
+
+	if (priv->irq > 0)
+		disable_irq(priv->irq);
+}
+
+/**
+ * tpm_cr50_i2c_transfer_message() - Transfer a message over i2c.
+ * @dev:	Device information.
+ * @adapter:	I2C adapter.
+ * @msg:	Message to transfer.
+ *
+ * Call unlocked i2c transfer routine with the provided parameters and
+ * retry in case of bus errors.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_transfer_message(struct device *dev,
+					 struct i2c_adapter *adapter,
+					 struct i2c_msg *msg)
+{
+	unsigned int try;
+	int rc;
+
+	for (try = 0; try < TPM_CR50_I2C_MAX_RETRIES; try++) {
+		rc = __i2c_transfer(adapter, msg, 1);
+		if (rc == 1)
+			return 0; /* Successfully transferred the message */
+		if (try)
+			dev_warn(dev, "i2c transfer failed (attempt %d/%d): %d\n",
+				 try + 1, TPM_CR50_I2C_MAX_RETRIES, rc);
+		usleep_range(TPM_CR50_I2C_RETRY_DELAY_LO, TPM_CR50_I2C_RETRY_DELAY_HI);
+	}
+
+	/* No i2c message transferred */
+	return -EIO;
+}
+
+/**
+ * tpm_cr50_i2c_read() - Read from TPM register.
+ * @chip:	A TPM chip.
+ * @addr:	Register address to read from.
+ * @buffer:	Read destination, provided by caller.
+ * @len:	Number of bytes to read.
+ *
+ * Sends the register address byte to the TPM, then waits until TPM
+ * is ready via interrupt signal or timeout expiration, then 'len'
+ * bytes are read from TPM response into the provided 'buffer'.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t len)
+{
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
+	struct i2c_msg msg_reg_addr = {
+		.addr = client->addr,
+		.len = 1,
+		.buf = &addr
+	};
+	struct i2c_msg msg_response = {
+		.addr = client->addr,
+		.flags = I2C_M_RD,
+		.len = len,
+		.buf = buffer
+	};
+	int rc;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	/* Prepare for completion interrupt */
+	tpm_cr50_i2c_enable_tpm_irq(chip);
+
+	/* Send the register address byte to the TPM */
+	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);
+	if (rc < 0)
+		goto out;
+
+	/* Wait for TPM to be ready with response data */
+	rc = tpm_cr50_i2c_wait_tpm_ready(chip);
+	if (rc < 0)
+		goto out;
+
+	/* Read response data from the TPM */
+	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);
+
+out:
+	tpm_cr50_i2c_disable_tpm_irq(chip);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	if (rc < 0)
+		return rc;
+
+	return 0;
+}
+
+/**
+ * tpm_cr50_i2c_write()- Write to TPM register.
+ * @chip:	A TPM chip.
+ * @addr:	Register address to write to.
+ * @buffer:	Data to write.
+ * @len:	Number of bytes to write.
+ *
+ * The provided address is prepended to the data in 'buffer', the
+ * cobined address+data is sent to the TPM, then wait for TPM to
+ * indicate it is done writing.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_write(struct tpm_chip *chip, u8 addr, u8 *buffer,
+			      size_t len)
+{
+	struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
+	struct i2c_client *client = to_i2c_client(chip->dev.parent);
+	struct i2c_msg msg = {
+		.addr = client->addr,
+		.len = len + 1,
+		.buf = priv->buf
+	};
+	int rc;
+
+	if (len > TPM_CR50_MAX_BUFSIZE - 1)
+		return -EINVAL;
+
+	/* Prepend the 'register address' to the buffer */
+	priv->buf[0] = addr;
+	memcpy(priv->buf + 1, buffer, len);
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	/* Prepare for completion interrupt */
+	tpm_cr50_i2c_enable_tpm_irq(chip);
+
+	/* Send write request buffer with address */
+	rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);
+	if (rc < 0)
+		goto out;
+
+	/* Wait for TPM to be ready, ignore timeout */
+	tpm_cr50_i2c_wait_tpm_ready(chip);
+
+out:
+	tpm_cr50_i2c_disable_tpm_irq(chip);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	if (rc < 0)
+		return rc;
+
+	return 0;
+}
+
+/**
+ * tpm_cr50_check_locality() - Verify TPM locality 0 is active.
+ * @chip: A TPM chip.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_check_locality(struct tpm_chip *chip)
+{
+	u8 mask = TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY;
+	u8 buf;
+	int rc;
+
+	rc = tpm_cr50_i2c_read(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));
+	if (rc < 0)
+		return rc;
+
+	if ((buf & mask) == mask)
+		return 0;
+
+	return -EIO;
+}
+
+/**
+ * tpm_cr50_release_locality() - Release TPM locality.
+ * @chip:	A TPM chip.
+ * @force:	Flag to force release if set.
+ */
+static void tpm_cr50_release_locality(struct tpm_chip *chip, bool force)
+{
+	u8 mask = TPM_ACCESS_VALID | TPM_ACCESS_REQUEST_PENDING;
+	u8 addr = TPM_I2C_ACCESS(0);
+	u8 buf;
+
+	if (tpm_cr50_i2c_read(chip, addr, &buf, sizeof(buf)) < 0)
+		return;
+
+	if (force || (buf & mask) == mask) {
+		buf = TPM_ACCESS_ACTIVE_LOCALITY;
+		tpm_cr50_i2c_write(chip, addr, &buf, sizeof(buf));
+	}
+}
+
+/**
+ * tpm_cr50_request_locality() - Request TPM locality 0.
+ * @chip: A TPM chip.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_request_locality(struct tpm_chip *chip)
+{
+	u8 buf = TPM_ACCESS_REQUEST_USE;
+	unsigned long stop;
+	int rc;
+
+	if (!tpm_cr50_check_locality(chip))
+		return 0;
+
+	rc = tpm_cr50_i2c_write(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));
+	if (rc < 0)
+		return rc;
+
+	stop = jiffies + chip->timeout_a;
+	do {
+		if (!tpm_cr50_check_locality(chip))
+			return 0;
+
+		msleep(TPM_CR50_TIMEOUT_SHORT_MS);
+	} while (time_before(jiffies, stop));
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * tpm_cr50_i2c_tis_status() - Read cr50 tis status.
+ * @chip: A TPM chip.
+ *
+ * cr50 requires all 4 bytes of status register to be read.
+ *
+ * Return:
+ *	TPM status byte.
+ */
+static u8 tpm_cr50_i2c_tis_status(struct tpm_chip *chip)
+{
+	u8 buf[4];
+
+	if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0)
+		return 0;
+
+	return buf[0];
+}
+
+/**
+ * tpm_cr50_i2c_tis_set_ready() - Set status register to ready.
+ * @chip: A TPM chip.
+ *
+ * cr50 requires all 4 bytes of status register to be written.
+ */
+static void tpm_cr50_i2c_tis_set_ready(struct tpm_chip *chip)
+{
+	u8 buf[4] = { TPM_STS_COMMAND_READY };
+
+	tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), buf, sizeof(buf));
+	msleep(TPM_CR50_TIMEOUT_SHORT_MS);
+}
+
+/**
+ * tpm_cr50_i2c_get_burst_and_status() - Get burst count and status.
+ * @chip:	A TPM chip.
+ * @mask:	Status mask.
+ * @burst:	Return value for burst.
+ * @status:	Return value for status.
+ *
+ * cr50 uses bytes 3:2 of status register for burst count and
+ * all 4 bytes must be read.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_get_burst_and_status(struct tpm_chip *chip, u8 mask,
+					     size_t *burst, u32 *status)
+{
+	unsigned long stop;
+	u8 buf[4];
+
+	*status = 0;
+
+	/* wait for burstcount */
+	stop = jiffies + chip->timeout_b;
+
+	do {
+		if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0) {
+			msleep(TPM_CR50_TIMEOUT_SHORT_MS);
+			continue;
+		}
+
+		*status = *buf;
+		*burst = le16_to_cpup((__le16 *)(buf + 1));
+
+		if ((*status & mask) == mask &&
+		    *burst > 0 && *burst <= TPM_CR50_MAX_BUFSIZE - 1)
+			return 0;
+
+		msleep(TPM_CR50_TIMEOUT_SHORT_MS);
+	} while (time_before(jiffies, stop));
+
+	dev_err(&chip->dev, "Timeout reading burst and status\n");
+	return -ETIMEDOUT;
+}
+
+/**
+ * tpm_cr50_i2c_tis_recv() - TPM reception callback.
+ * @chip:	A TPM chip.
+ * @buf:	Reception buffer.
+ * @buf_len:	Buffer length to read.
+ *
+ * Return:
+ * - >= 0:	Number of read bytes.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
+{
+
+	u8 mask = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
+	size_t burstcnt, cur, len, expected;
+	u8 addr = TPM_I2C_DATA_FIFO(0);
+	u32 status;
+	int rc;
+
+	if (buf_len < TPM_HEADER_SIZE)
+		return -EINVAL;
+
+	rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
+	if (rc < 0)
+		goto out_err;
+
+	if (burstcnt > buf_len || burstcnt < TPM_HEADER_SIZE) {
+		dev_err(&chip->dev,
+			"Unexpected burstcnt: %zu (max=%zu, min=%d)\n",
+			burstcnt, buf_len, TPM_HEADER_SIZE);
+		rc = -EIO;
+		goto out_err;
+	}
+
+	/* Read first chunk of burstcnt bytes */
+	rc = tpm_cr50_i2c_read(chip, addr, buf, burstcnt);
+	if (rc < 0) {
+		dev_err(&chip->dev, "Read of first chunk failed\n");
+		goto out_err;
+	}
+
+	/* Determine expected data in the return buffer */
+	expected = be32_to_cpup((__be32 *)(buf + 2));
+	if (expected > buf_len) {
+		dev_err(&chip->dev, "Buffer too small to receive i2c data\n");
+		rc = -E2BIG;
+		goto out_err;
+	}
+
+	/* Now read the rest of the data */
+	cur = burstcnt;
+	while (cur < expected) {
+		/* Read updated burst count and check status */
+		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
+		if (rc < 0)
+			goto out_err;
+
+		len = min_t(size_t, burstcnt, expected - cur);
+		rc = tpm_cr50_i2c_read(chip, addr, buf + cur, len);
+		if (rc < 0) {
+			dev_err(&chip->dev, "Read failed\n");
+			goto out_err;
+		}
+
+		cur += len;
+	}
+
+	/* Ensure TPM is done reading data */
+	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);
+	if (rc < 0)
+		goto out_err;
+	if (status & TPM_STS_DATA_AVAIL) {
+		dev_err(&chip->dev, "Data still available\n");
+		rc = -EIO;
+		goto out_err;
+	}
+
+	tpm_cr50_release_locality(chip, false);
+	return cur;
+
+out_err:
+	/* Abort current transaction if still pending */
+	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
+		tpm_cr50_i2c_tis_set_ready(chip);
+
+	tpm_cr50_release_locality(chip, false);
+	return rc;
+}
+
+/**
+ * tpm_cr50_i2c_tis_send() - TPM transmission callback.
+ * @chip:	A TPM chip.
+ * @buf:	Buffer to send.
+ * @len:	Buffer length.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+	size_t burstcnt, limit, sent = 0;
+	u8 tpm_go[4] = { TPM_STS_GO };
+	unsigned long stop;
+	u32 status;
+	int rc;
+
+	rc = tpm_cr50_request_locality(chip);
+	if (rc < 0)
+		return rc;
+
+	/* Wait until TPM is ready for a command */
+	stop = jiffies + chip->timeout_b;
+	while (!(tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)) {
+		if (time_after(jiffies, stop)) {
+			rc = -ETIMEDOUT;
+			goto out_err;
+		}
+
+		tpm_cr50_i2c_tis_set_ready(chip);
+	}
+
+	while (len > 0) {
+		u8 mask = TPM_STS_VALID;
+
+		/* Wait for data if this is not the first chunk */
+		if (sent > 0)
+			mask |= TPM_STS_DATA_EXPECT;
+
+		/* Read burst count and check status */
+		rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
+		if (rc < 0)
+			goto out_err;
+
+		/*
+		 * Use burstcnt - 1 to account for the address byte
+		 * that is inserted by tpm_cr50_i2c_write()
+		 */
+		limit = min_t(size_t, burstcnt - 1, len);
+		rc = tpm_cr50_i2c_write(chip, TPM_I2C_DATA_FIFO(0), &buf[sent], limit);
+		if (rc < 0) {
+			dev_err(&chip->dev, "Write failed\n");
+			goto out_err;
+		}
+
+		sent += limit;
+		len -= limit;
+	}
+
+	/* Ensure TPM is not expecting more data */
+	rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);
+	if (rc < 0)
+		goto out_err;
+	if (status & TPM_STS_DATA_EXPECT) {
+		dev_err(&chip->dev, "Data still expected\n");
+		rc = -EIO;
+		goto out_err;
+	}
+
+	/* Start the TPM command */
+	rc = tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), tpm_go,
+				sizeof(tpm_go));
+	if (rc < 0) {
+		dev_err(&chip->dev, "Start command failed\n");
+		goto out_err;
+	}
+	return 0;
+
+out_err:
+	/* Abort current transaction if still pending */
+	if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
+		tpm_cr50_i2c_tis_set_ready(chip);
+
+	tpm_cr50_release_locality(chip, false);
+	return rc;
+}
+
+/**
+ * tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
+ * @chip:	A TPM chip.
+ * @status:	Status given by the cancel callback.
+ *
+ * Return:
+ *	True if command is ready, False otherwise.
+ */
+static bool tpm_cr50_i2c_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	return status == TPM_STS_COMMAND_READY;
+}
+
+static bool tpm_cr50_i2c_is_firmware_power_managed(struct device *dev)
+{
+	u8 val;
+	int ret;
+
+	/* This flag should default true when the device property is not present */
+	ret = device_property_read_u8(dev, "firmware-power-managed", &val);
+	if (ret)
+		return true;
+
+	return val;
+}
+
+static const struct tpm_class_ops cr50_i2c = {
+	.flags = TPM_OPS_AUTO_STARTUP,
+	.status = &tpm_cr50_i2c_tis_status,
+	.recv = &tpm_cr50_i2c_tis_recv,
+	.send = &tpm_cr50_i2c_tis_send,
+	.cancel = &tpm_cr50_i2c_tis_set_ready,
+	.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+	.req_canceled = &tpm_cr50_i2c_req_canceled,
+};
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id cr50_i2c_acpi_id[] = {
+	{ "GOOG0005", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, cr50_i2c_acpi_id);
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_cr50_i2c_match[] = {
+	{ .compatible = "google,cr50", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_cr50_i2c_match);
+#endif
+
+/**
+ * tpm_cr50_i2c_probe() - Driver probe function.
+ * @client:	I2C client information.
+ * @id:		I2C device id.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static int tpm_cr50_i2c_probe(struct i2c_client *client)
+{
+	struct tpm_i2c_cr50_priv_data *priv;
+	struct device *dev = &client->dev;
+	struct tpm_chip *chip;
+	u32 vendor;
+	u8 buf[4];
+	int rc;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return -ENODEV;
+
+	chip = tpmm_chip_alloc(dev, &cr50_i2c);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* cr50 is a TPM 2.0 chip */
+	chip->flags |= TPM_CHIP_FLAG_TPM2;
+	if (tpm_cr50_i2c_is_firmware_power_managed(dev))
+		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED;
+
+	/* Default timeouts */
+	chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+	chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
+	chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+	chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+
+	dev_set_drvdata(&chip->dev, priv);
+	init_completion(&priv->tpm_ready);
+
+	if (client->irq > 0) {
+		rc = devm_request_irq(dev, client->irq, tpm_cr50_i2c_int_handler,
+				      IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
+				      IRQF_NO_AUTOEN,
+				      dev->driver->name, chip);
+		if (rc < 0) {
+			dev_err(dev, "Failed to probe IRQ %d\n", client->irq);
+			return rc;
+		}
+
+		priv->irq = client->irq;
+	} else {
+		dev_warn(dev, "No IRQ, will use %ums delay for TPM ready\n",
+			 TPM_CR50_TIMEOUT_NOIRQ_MS);
+	}
+
+	rc = tpm_cr50_request_locality(chip);
+	if (rc < 0) {
+		dev_err(dev, "Could not request locality\n");
+		return rc;
+	}
+
+	/* Read four bytes from DID_VID register */
+	rc = tpm_cr50_i2c_read(chip, TPM_I2C_DID_VID(0), buf, sizeof(buf));
+	if (rc < 0) {
+		dev_err(dev, "Could not read vendor id\n");
+		tpm_cr50_release_locality(chip, true);
+		return rc;
+	}
+
+	vendor = le32_to_cpup((__le32 *)buf);
+	if (vendor != TPM_CR50_I2C_DID_VID && vendor != TPM_TI50_I2C_DID_VID) {
+		dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor);
+		tpm_cr50_release_locality(chip, true);
+		return -ENODEV;
+	}
+
+	dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n",
+		 vendor == TPM_TI50_I2C_DID_VID ? "ti50" : "cr50",
+		 client->addr, client->irq, vendor >> 16);
+	return tpm_chip_register(chip);
+}
+
+/**
+ * tpm_cr50_i2c_remove() - Driver remove function.
+ * @client: I2C client information.
+ *
+ * Return:
+ * - 0:		Success.
+ * - -errno:	A POSIX error code.
+ */
+static void tpm_cr50_i2c_remove(struct i2c_client *client)
+{
+	struct tpm_chip *chip = i2c_get_clientdata(client);
+	struct device *dev = &client->dev;
+
+	if (!chip) {
+		dev_crit(dev, "Could not get client data at remove, memory corruption ahead\n");
+		return;
+	}
+
+	tpm_chip_unregister(chip);
+	tpm_cr50_release_locality(chip, true);
+}
+
+static SIMPLE_DEV_PM_OPS(cr50_i2c_pm, tpm_pm_suspend, tpm_pm_resume);
+
+static struct i2c_driver cr50_i2c_driver = {
+	.probe_new = tpm_cr50_i2c_probe,
+	.remove = tpm_cr50_i2c_remove,
+	.driver = {
+		.name = "cr50_i2c",
+		.pm = &cr50_i2c_pm,
+		.acpi_match_table = ACPI_PTR(cr50_i2c_acpi_id),
+		.of_match_table = of_match_ptr(of_cr50_i2c_match),
+	},
+};
+
+module_i2c_driver(cr50_i2c_driver);
+
+MODULE_DESCRIPTION("cr50 TPM I2C Driver");
+MODULE_LICENSE("GPL");