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, 1946 insertions, 0 deletions

diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c
new file mode 100644
index 000000000..c2d279222
--- /dev/null
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -0,0 +1,1946 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * dvb_ca.c: generic DVB functions for EN50221 CAM interfaces
+ *
+ * Copyright (C) 2004 Andrew de Quincey
+ *
+ * Parts of this file were based on sources as follows:
+ *
+ * Copyright (C) 2003 Ralph Metzler <rjkm@metzlerbros.de>
+ *
+ * based on code:
+ *
+ * Copyright (C) 1999-2002 Ralph  Metzler
+ *                       & Marcus Metzler for convergence integrated media GmbH
+ */
+
+#define pr_fmt(fmt) "dvb_ca_en50221: " fmt
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/nospec.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/sched/signal.h>
+#include <linux/kthread.h>
+
+#include <media/dvb_ca_en50221.h>
+#include <media/dvb_ringbuffer.h>
+
+static int dvb_ca_en50221_debug;
+
+module_param_named(cam_debug, dvb_ca_en50221_debug, int, 0644);
+MODULE_PARM_DESC(cam_debug, "enable verbose debug messages");
+
+#define dprintk(fmt, arg...) do {					\
+	if (dvb_ca_en50221_debug)					\
+		printk(KERN_DEBUG pr_fmt("%s: " fmt), __func__, ##arg);\
+} while (0)
+
+#define INIT_TIMEOUT_SECS 10
+
+#define HOST_LINK_BUF_SIZE 0x200
+
+#define RX_BUFFER_SIZE 65535
+
+#define MAX_RX_PACKETS_PER_ITERATION 10
+
+#define CTRLIF_DATA      0
+#define CTRLIF_COMMAND   1
+#define CTRLIF_STATUS    1
+#define CTRLIF_SIZE_LOW  2
+#define CTRLIF_SIZE_HIGH 3
+
+#define CMDREG_HC        1	/* Host control */
+#define CMDREG_SW        2	/* Size write */
+#define CMDREG_SR        4	/* Size read */
+#define CMDREG_RS        8	/* Reset interface */
+#define CMDREG_FRIE   0x40	/* Enable FR interrupt */
+#define CMDREG_DAIE   0x80	/* Enable DA interrupt */
+#define IRQEN (CMDREG_DAIE)
+
+#define STATUSREG_RE     1	/* read error */
+#define STATUSREG_WE     2	/* write error */
+#define STATUSREG_FR  0x40	/* module free */
+#define STATUSREG_DA  0x80	/* data available */
+
+#define DVB_CA_SLOTSTATE_NONE           0
+#define DVB_CA_SLOTSTATE_UNINITIALISED  1
+#define DVB_CA_SLOTSTATE_RUNNING        2
+#define DVB_CA_SLOTSTATE_INVALID        3
+#define DVB_CA_SLOTSTATE_WAITREADY      4
+#define DVB_CA_SLOTSTATE_VALIDATE       5
+#define DVB_CA_SLOTSTATE_WAITFR         6
+#define DVB_CA_SLOTSTATE_LINKINIT       7
+
+/* Information on a CA slot */
+struct dvb_ca_slot {
+	/* current state of the CAM */
+	int slot_state;
+
+	/* mutex used for serializing access to one CI slot */
+	struct mutex slot_lock;
+
+	/* Number of CAMCHANGES that have occurred since last processing */
+	atomic_t camchange_count;
+
+	/* Type of last CAMCHANGE */
+	int camchange_type;
+
+	/* base address of CAM config */
+	u32 config_base;
+
+	/* value to write into Config Control register */
+	u8 config_option;
+
+	/* if 1, the CAM supports DA IRQs */
+	u8 da_irq_supported:1;
+
+	/* size of the buffer to use when talking to the CAM */
+	int link_buf_size;
+
+	/* buffer for incoming packets */
+	struct dvb_ringbuffer rx_buffer;
+
+	/* timer used during various states of the slot */
+	unsigned long timeout;
+};
+
+/* Private CA-interface information */
+struct dvb_ca_private {
+	struct kref refcount;
+
+	/* pointer back to the public data structure */
+	struct dvb_ca_en50221 *pub;
+
+	/* the DVB device */
+	struct dvb_device *dvbdev;
+
+	/* Flags describing the interface (DVB_CA_FLAG_*) */
+	u32 flags;
+
+	/* number of slots supported by this CA interface */
+	unsigned int slot_count;
+
+	/* information on each slot */
+	struct dvb_ca_slot *slot_info;
+
+	/* wait queues for read() and write() operations */
+	wait_queue_head_t wait_queue;
+
+	/* PID of the monitoring thread */
+	struct task_struct *thread;
+
+	/* Flag indicating if the CA device is open */
+	unsigned int open:1;
+
+	/* Flag indicating the thread should wake up now */
+	unsigned int wakeup:1;
+
+	/* Delay the main thread should use */
+	unsigned long delay;
+
+	/*
+	 * Slot to start looking for data to read from in the next user-space
+	 * read operation
+	 */
+	int next_read_slot;
+
+	/* mutex serializing ioctls */
+	struct mutex ioctl_mutex;
+};
+
+static void dvb_ca_private_free(struct dvb_ca_private *ca)
+{
+	unsigned int i;
+
+	dvb_device_put(ca->dvbdev);
+	for (i = 0; i < ca->slot_count; i++)
+		vfree(ca->slot_info[i].rx_buffer.data);
+
+	kfree(ca->slot_info);
+	kfree(ca);
+}
+
+static void dvb_ca_private_release(struct kref *ref)
+{
+	struct dvb_ca_private *ca;
+
+	ca = container_of(ref, struct dvb_ca_private, refcount);
+	dvb_ca_private_free(ca);
+}
+
+static void dvb_ca_private_get(struct dvb_ca_private *ca)
+{
+	kref_get(&ca->refcount);
+}
+
+static void dvb_ca_private_put(struct dvb_ca_private *ca)
+{
+	kref_put(&ca->refcount, dvb_ca_private_release);
+}
+
+static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca);
+static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
+				    u8 *ebuf, int ecount);
+static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
+				     u8 *ebuf, int ecount);
+
+/**
+ * findstr - Safely find needle in haystack.
+ *
+ * @haystack: Buffer to look in.
+ * @hlen: Number of bytes in haystack.
+ * @needle: Buffer to find.
+ * @nlen: Number of bytes in needle.
+ * return: Pointer into haystack needle was found at, or NULL if not found.
+ */
+static char *findstr(char *haystack, int hlen, char *needle, int nlen)
+{
+	int i;
+
+	if (hlen < nlen)
+		return NULL;
+
+	for (i = 0; i <= hlen - nlen; i++) {
+		if (!strncmp(haystack + i, needle, nlen))
+			return haystack + i;
+	}
+
+	return NULL;
+}
+
+/* ************************************************************************** */
+/* EN50221 physical interface functions */
+
+/*
+ * dvb_ca_en50221_check_camstatus - Check CAM status.
+ */
+static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private *ca, int slot)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int slot_status;
+	int cam_present_now;
+	int cam_changed;
+
+	/* IRQ mode */
+	if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
+		return (atomic_read(&sl->camchange_count) != 0);
+
+	/* poll mode */
+	slot_status = ca->pub->poll_slot_status(ca->pub, slot, ca->open);
+
+	cam_present_now = (slot_status & DVB_CA_EN50221_POLL_CAM_PRESENT) ? 1 : 0;
+	cam_changed = (slot_status & DVB_CA_EN50221_POLL_CAM_CHANGED) ? 1 : 0;
+	if (!cam_changed) {
+		int cam_present_old = (sl->slot_state != DVB_CA_SLOTSTATE_NONE);
+
+		cam_changed = (cam_present_now != cam_present_old);
+	}
+
+	if (cam_changed) {
+		if (!cam_present_now)
+			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
+		else
+			sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
+		atomic_set(&sl->camchange_count, 1);
+	} else {
+		if ((sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
+		    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
+			/* move to validate state if reset is completed */
+			sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+		}
+	}
+
+	return cam_changed;
+}
+
+/**
+ * dvb_ca_en50221_wait_if_status - Wait for flags to become set on the STATUS
+ *	 register on a CAM interface, checking for errors and timeout.
+ *
+ * @ca: CA instance.
+ * @slot: Slot on interface.
+ * @waitfor: Flags to wait for.
+ * @timeout_hz: Timeout in milliseconds.
+ *
+ * return: 0 on success, nonzero on error.
+ */
+static int dvb_ca_en50221_wait_if_status(struct dvb_ca_private *ca, int slot,
+					 u8 waitfor, int timeout_hz)
+{
+	unsigned long timeout;
+	unsigned long start;
+
+	dprintk("%s\n", __func__);
+
+	/* loop until timeout elapsed */
+	start = jiffies;
+	timeout = jiffies + timeout_hz;
+	while (1) {
+		int res;
+
+		/* read the status and check for error */
+		res = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+		if (res < 0)
+			return -EIO;
+
+		/* if we got the flags, it was successful! */
+		if (res & waitfor) {
+			dprintk("%s succeeded timeout:%lu\n",
+				__func__, jiffies - start);
+			return 0;
+		}
+
+		/* check for timeout */
+		if (time_after(jiffies, timeout))
+			break;
+
+		/* wait for a bit */
+		usleep_range(1000, 1100);
+	}
+
+	dprintk("%s failed timeout:%lu\n", __func__, jiffies - start);
+
+	/* if we get here, we've timed out */
+	return -ETIMEDOUT;
+}
+
+/**
+ * dvb_ca_en50221_link_init - Initialise the link layer connection to a CAM.
+ *
+ * @ca: CA instance.
+ * @slot: Slot id.
+ *
+ * return: 0 on success, nonzero on failure.
+ */
+static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int ret;
+	int buf_size;
+	u8 buf[2];
+
+	dprintk("%s\n", __func__);
+
+	/* we'll be determining these during this function */
+	sl->da_irq_supported = 0;
+
+	/*
+	 * set the host link buffer size temporarily. it will be overwritten
+	 * with the real negotiated size later.
+	 */
+	sl->link_buf_size = 2;
+
+	/* read the buffer size from the CAM */
+	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
+					 IRQEN | CMDREG_SR);
+	if (ret)
+		return ret;
+	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ);
+	if (ret)
+		return ret;
+	ret = dvb_ca_en50221_read_data(ca, slot, buf, 2);
+	if (ret != 2)
+		return -EIO;
+	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
+	if (ret)
+		return ret;
+
+	/*
+	 * store it, and choose the minimum of our buffer and the CAM's buffer
+	 * size
+	 */
+	buf_size = (buf[0] << 8) | buf[1];
+	if (buf_size > HOST_LINK_BUF_SIZE)
+		buf_size = HOST_LINK_BUF_SIZE;
+	sl->link_buf_size = buf_size;
+	buf[0] = buf_size >> 8;
+	buf[1] = buf_size & 0xff;
+	dprintk("Chosen link buffer size of %i\n", buf_size);
+
+	/* write the buffer size to the CAM */
+	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
+					 IRQEN | CMDREG_SW);
+	if (ret)
+		return ret;
+	ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10);
+	if (ret)
+		return ret;
+	ret = dvb_ca_en50221_write_data(ca, slot, buf, 2);
+	if (ret != 2)
+		return -EIO;
+	ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
+	if (ret)
+		return ret;
+
+	/* success */
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_read_tuple - Read a tuple from attribute memory.
+ *
+ * @ca: CA instance.
+ * @slot: Slot id.
+ * @address: Address to read from. Updated.
+ * @tuple_type: Tuple id byte. Updated.
+ * @tuple_length: Tuple length. Updated.
+ * @tuple: Dest buffer for tuple (must be 256 bytes). Updated.
+ *
+ * return: 0 on success, nonzero on error.
+ */
+static int dvb_ca_en50221_read_tuple(struct dvb_ca_private *ca, int slot,
+				     int *address, int *tuple_type,
+				     int *tuple_length, u8 *tuple)
+{
+	int i;
+	int _tuple_type;
+	int _tuple_length;
+	int _address = *address;
+
+	/* grab the next tuple length and type */
+	_tuple_type = ca->pub->read_attribute_mem(ca->pub, slot, _address);
+	if (_tuple_type < 0)
+		return _tuple_type;
+	if (_tuple_type == 0xff) {
+		dprintk("END OF CHAIN TUPLE type:0x%x\n", _tuple_type);
+		*address += 2;
+		*tuple_type = _tuple_type;
+		*tuple_length = 0;
+		return 0;
+	}
+	_tuple_length = ca->pub->read_attribute_mem(ca->pub, slot,
+						    _address + 2);
+	if (_tuple_length < 0)
+		return _tuple_length;
+	_address += 4;
+
+	dprintk("TUPLE type:0x%x length:%i\n", _tuple_type, _tuple_length);
+
+	/* read in the whole tuple */
+	for (i = 0; i < _tuple_length; i++) {
+		tuple[i] = ca->pub->read_attribute_mem(ca->pub, slot,
+						       _address + (i * 2));
+		dprintk("  0x%02x: 0x%02x %c\n",
+			i, tuple[i] & 0xff,
+			((tuple[i] > 31) && (tuple[i] < 127)) ? tuple[i] : '.');
+	}
+	_address += (_tuple_length * 2);
+
+	/* success */
+	*tuple_type = _tuple_type;
+	*tuple_length = _tuple_length;
+	*address = _address;
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_parse_attributes - Parse attribute memory of a CAM module,
+ *	extracting Config register, and checking it is a DVB CAM module.
+ *
+ * @ca: CA instance.
+ * @slot: Slot id.
+ *
+ * return: 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private *ca, int slot)
+{
+	struct dvb_ca_slot *sl;
+	int address = 0;
+	int tuple_length;
+	int tuple_type;
+	u8 tuple[257];
+	char *dvb_str;
+	int rasz;
+	int status;
+	int got_cftableentry = 0;
+	int end_chain = 0;
+	int i;
+	u16 manfid = 0;
+	u16 devid = 0;
+
+	/* CISTPL_DEVICE_0A */
+	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
+					   &tuple_length, tuple);
+	if (status < 0)
+		return status;
+	if (tuple_type != 0x1D)
+		return -EINVAL;
+
+	/* CISTPL_DEVICE_0C */
+	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
+					   &tuple_length, tuple);
+	if (status < 0)
+		return status;
+	if (tuple_type != 0x1C)
+		return -EINVAL;
+
+	/* CISTPL_VERS_1 */
+	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
+					   &tuple_length, tuple);
+	if (status < 0)
+		return status;
+	if (tuple_type != 0x15)
+		return -EINVAL;
+
+	/* CISTPL_MANFID */
+	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
+					   &tuple_length, tuple);
+	if (status < 0)
+		return status;
+	if (tuple_type != 0x20)
+		return -EINVAL;
+	if (tuple_length != 4)
+		return -EINVAL;
+	manfid = (tuple[1] << 8) | tuple[0];
+	devid = (tuple[3] << 8) | tuple[2];
+
+	/* CISTPL_CONFIG */
+	status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tuple_type,
+					   &tuple_length, tuple);
+	if (status < 0)
+		return status;
+	if (tuple_type != 0x1A)
+		return -EINVAL;
+	if (tuple_length < 3)
+		return -EINVAL;
+
+	/* extract the configbase */
+	rasz = tuple[0] & 3;
+	if (tuple_length < (3 + rasz + 14))
+		return -EINVAL;
+	sl = &ca->slot_info[slot];
+	sl->config_base = 0;
+	for (i = 0; i < rasz + 1; i++)
+		sl->config_base |= (tuple[2 + i] << (8 * i));
+
+	/* check it contains the correct DVB string */
+	dvb_str = findstr((char *)tuple, tuple_length, "DVB_CI_V", 8);
+	if (!dvb_str)
+		return -EINVAL;
+	if (tuple_length < ((dvb_str - (char *)tuple) + 12))
+		return -EINVAL;
+
+	/* is it a version we support? */
+	if (strncmp(dvb_str + 8, "1.00", 4)) {
+		pr_err("dvb_ca adapter %d: Unsupported DVB CAM module version %c%c%c%c\n",
+		       ca->dvbdev->adapter->num, dvb_str[8], dvb_str[9],
+		       dvb_str[10], dvb_str[11]);
+		return -EINVAL;
+	}
+
+	/* process the CFTABLE_ENTRY tuples, and any after those */
+	while ((!end_chain) && (address < 0x1000)) {
+		status = dvb_ca_en50221_read_tuple(ca, slot, &address,
+						   &tuple_type, &tuple_length,
+						   tuple);
+		if (status < 0)
+			return status;
+		switch (tuple_type) {
+		case 0x1B:	/* CISTPL_CFTABLE_ENTRY */
+			if (tuple_length < (2 + 11 + 17))
+				break;
+
+			/* if we've already parsed one, just use it */
+			if (got_cftableentry)
+				break;
+
+			/* get the config option */
+			sl->config_option = tuple[0] & 0x3f;
+
+			/* OK, check it contains the correct strings */
+			if (!findstr((char *)tuple, tuple_length,
+				     "DVB_HOST", 8) ||
+			    !findstr((char *)tuple, tuple_length,
+				     "DVB_CI_MODULE", 13))
+				break;
+
+			got_cftableentry = 1;
+			break;
+
+		case 0x14:	/* CISTPL_NO_LINK */
+			break;
+
+		case 0xFF:	/* CISTPL_END */
+			end_chain = 1;
+			break;
+
+		default:	/* Unknown tuple type - just skip this tuple */
+			dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n",
+				tuple_type, tuple_length);
+			break;
+		}
+	}
+
+	if ((address > 0x1000) || (!got_cftableentry))
+		return -EINVAL;
+
+	dprintk("Valid DVB CAM detected MANID:%x DEVID:%x CONFIGBASE:0x%x CONFIGOPTION:0x%x\n",
+		manfid, devid, sl->config_base, sl->config_option);
+
+	/* success! */
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_set_configoption - Set CAM's configoption correctly.
+ *
+ * @ca: CA instance.
+ * @slot: Slot containing the CAM.
+ */
+static int dvb_ca_en50221_set_configoption(struct dvb_ca_private *ca, int slot)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int configoption;
+
+	dprintk("%s\n", __func__);
+
+	/* set the config option */
+	ca->pub->write_attribute_mem(ca->pub, slot, sl->config_base,
+				     sl->config_option);
+
+	/* check it */
+	configoption = ca->pub->read_attribute_mem(ca->pub, slot,
+						   sl->config_base);
+	dprintk("Set configoption 0x%x, read configoption 0x%x\n",
+		sl->config_option, configoption & 0x3f);
+
+	/* fine! */
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_read_data - This function talks to an EN50221 CAM control
+ *	interface. It reads a buffer of data from the CAM. The data can either
+ *	be stored in a supplied buffer, or automatically be added to the slot's
+ *	rx_buffer.
+ *
+ * @ca: CA instance.
+ * @slot: Slot to read from.
+ * @ebuf: If non-NULL, the data will be written to this buffer. If NULL,
+ *	  the data will be added into the buffering system as a normal
+ *	  fragment.
+ * @ecount: Size of ebuf. Ignored if ebuf is NULL.
+ *
+ * return: Number of bytes read, or < 0 on error
+ */
+static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot,
+				    u8 *ebuf, int ecount)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int bytes_read;
+	int status;
+	u8 buf[HOST_LINK_BUF_SIZE];
+	int i;
+
+	dprintk("%s\n", __func__);
+
+	/* check if we have space for a link buf in the rx_buffer */
+	if (!ebuf) {
+		int buf_free;
+
+		if (!sl->rx_buffer.data) {
+			status = -EIO;
+			goto exit;
+		}
+		buf_free = dvb_ringbuffer_free(&sl->rx_buffer);
+
+		if (buf_free < (sl->link_buf_size +
+				DVB_RINGBUFFER_PKTHDRSIZE)) {
+			status = -EAGAIN;
+			goto exit;
+		}
+	}
+
+	if (ca->pub->read_data &&
+	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT)) {
+		if (!ebuf)
+			status = ca->pub->read_data(ca->pub, slot, buf,
+						    sizeof(buf));
+		else
+			status = ca->pub->read_data(ca->pub, slot, buf, ecount);
+		if (status < 0)
+			return status;
+		bytes_read =  status;
+		if (status == 0)
+			goto exit;
+	} else {
+		/* check if there is data available */
+		status = ca->pub->read_cam_control(ca->pub, slot,
+						   CTRLIF_STATUS);
+		if (status < 0)
+			goto exit;
+		if (!(status & STATUSREG_DA)) {
+			/* no data */
+			status = 0;
+			goto exit;
+		}
+
+		/* read the amount of data */
+		status = ca->pub->read_cam_control(ca->pub, slot,
+						   CTRLIF_SIZE_HIGH);
+		if (status < 0)
+			goto exit;
+		bytes_read = status << 8;
+		status = ca->pub->read_cam_control(ca->pub, slot,
+						   CTRLIF_SIZE_LOW);
+		if (status < 0)
+			goto exit;
+		bytes_read |= status;
+
+		/* check it will fit */
+		if (!ebuf) {
+			if (bytes_read > sl->link_buf_size) {
+				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the link buffer size (%i > %i)!\n",
+				       ca->dvbdev->adapter->num, bytes_read,
+				       sl->link_buf_size);
+				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+				status = -EIO;
+				goto exit;
+			}
+			if (bytes_read < 2) {
+				pr_err("dvb_ca adapter %d: CAM sent a buffer that was less than 2 bytes!\n",
+				       ca->dvbdev->adapter->num);
+				sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+				status = -EIO;
+				goto exit;
+			}
+		} else {
+			if (bytes_read > ecount) {
+				pr_err("dvb_ca adapter %d: CAM tried to send a buffer larger than the ecount size!\n",
+				       ca->dvbdev->adapter->num);
+				status = -EIO;
+				goto exit;
+			}
+		}
+
+		/* fill the buffer */
+		for (i = 0; i < bytes_read; i++) {
+			/* read byte and check */
+			status = ca->pub->read_cam_control(ca->pub, slot,
+							   CTRLIF_DATA);
+			if (status < 0)
+				goto exit;
+
+			/* OK, store it in the buffer */
+			buf[i] = status;
+		}
+
+		/* check for read error (RE should now be 0) */
+		status = ca->pub->read_cam_control(ca->pub, slot,
+						   CTRLIF_STATUS);
+		if (status < 0)
+			goto exit;
+		if (status & STATUSREG_RE) {
+			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+			status = -EIO;
+			goto exit;
+		}
+	}
+
+	/*
+	 * OK, add it to the receive buffer, or copy into external buffer if
+	 * supplied
+	 */
+	if (!ebuf) {
+		if (!sl->rx_buffer.data) {
+			status = -EIO;
+			goto exit;
+		}
+		dvb_ringbuffer_pkt_write(&sl->rx_buffer, buf, bytes_read);
+	} else {
+		memcpy(ebuf, buf, bytes_read);
+	}
+
+	dprintk("Received CA packet for slot %i connection id 0x%x last_frag:%i size:0x%x\n", slot,
+		buf[0], (buf[1] & 0x80) == 0, bytes_read);
+
+	/* wake up readers when a last_fragment is received */
+	if ((buf[1] & 0x80) == 0x00)
+		wake_up_interruptible(&ca->wait_queue);
+
+	status = bytes_read;
+
+exit:
+	return status;
+}
+
+/**
+ * dvb_ca_en50221_write_data - This function talks to an EN50221 CAM control
+ *				interface. It writes a buffer of data to a CAM.
+ *
+ * @ca: CA instance.
+ * @slot: Slot to write to.
+ * @buf: The data in this buffer is treated as a complete link-level packet to
+ *	 be written.
+ * @bytes_write: Size of ebuf.
+ *
+ * return: Number of bytes written, or < 0 on error.
+ */
+static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot,
+				     u8 *buf, int bytes_write)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int status;
+	int i;
+
+	dprintk("%s\n", __func__);
+
+	/* sanity check */
+	if (bytes_write > sl->link_buf_size)
+		return -EINVAL;
+
+	if (ca->pub->write_data &&
+	    (sl->slot_state != DVB_CA_SLOTSTATE_LINKINIT))
+		return ca->pub->write_data(ca->pub, slot, buf, bytes_write);
+
+	/*
+	 * it is possible we are dealing with a single buffer implementation,
+	 * thus if there is data available for read or if there is even a read
+	 * already in progress, we do nothing but awake the kernel thread to
+	 * process the data if necessary.
+	 */
+	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+	if (status < 0)
+		goto exitnowrite;
+	if (status & (STATUSREG_DA | STATUSREG_RE)) {
+		if (status & STATUSREG_DA)
+			dvb_ca_en50221_thread_wakeup(ca);
+
+		status = -EAGAIN;
+		goto exitnowrite;
+	}
+
+	/* OK, set HC bit */
+	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
+					    IRQEN | CMDREG_HC);
+	if (status)
+		goto exit;
+
+	/* check if interface is still free */
+	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+	if (status < 0)
+		goto exit;
+	if (!(status & STATUSREG_FR)) {
+		/* it wasn't free => try again later */
+		status = -EAGAIN;
+		goto exit;
+	}
+
+	/*
+	 * It may need some time for the CAM to settle down, or there might
+	 * be a race condition between the CAM, writing HC and our last
+	 * check for DA. This happens, if the CAM asserts DA, just after
+	 * checking DA before we are setting HC. In this case it might be
+	 * a bug in the CAM to keep the FR bit, the lower layer/HW
+	 * communication requires a longer timeout or the CAM needs more
+	 * time internally. But this happens in reality!
+	 * We need to read the status from the HW again and do the same
+	 * we did for the previous check for DA
+	 */
+	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+	if (status < 0)
+		goto exit;
+
+	if (status & (STATUSREG_DA | STATUSREG_RE)) {
+		if (status & STATUSREG_DA)
+			dvb_ca_en50221_thread_wakeup(ca);
+
+		status = -EAGAIN;
+		goto exit;
+	}
+
+	/* send the amount of data */
+	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH,
+					    bytes_write >> 8);
+	if (status)
+		goto exit;
+	status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW,
+					    bytes_write & 0xff);
+	if (status)
+		goto exit;
+
+	/* send the buffer */
+	for (i = 0; i < bytes_write; i++) {
+		status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA,
+						    buf[i]);
+		if (status)
+			goto exit;
+	}
+
+	/* check for write error (WE should now be 0) */
+	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+	if (status < 0)
+		goto exit;
+	if (status & STATUSREG_WE) {
+		sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+		status = -EIO;
+		goto exit;
+	}
+	status = bytes_write;
+
+	dprintk("Wrote CA packet for slot %i, connection id 0x%x last_frag:%i size:0x%x\n", slot,
+		buf[0], (buf[1] & 0x80) == 0, bytes_write);
+
+exit:
+	ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN);
+
+exitnowrite:
+	return status;
+}
+
+/* ************************************************************************** */
+/* EN50221 higher level functions */
+
+/**
+ * dvb_ca_en50221_slot_shutdown - A CAM has been removed => shut it down.
+ *
+ * @ca: CA instance.
+ * @slot: Slot to shut down.
+ */
+static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private *ca, int slot)
+{
+	dprintk("%s\n", __func__);
+
+	ca->pub->slot_shutdown(ca->pub, slot);
+	ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
+
+	/*
+	 * need to wake up all processes to check if they're now trying to
+	 * write to a defunct CAM
+	 */
+	wake_up_interruptible(&ca->wait_queue);
+
+	dprintk("Slot %i shutdown\n", slot);
+
+	/* success */
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_camchange_irq - A CAMCHANGE IRQ has occurred.
+ *
+ * @pubca: CA instance.
+ * @slot: Slot concerned.
+ * @change_type: One of the DVB_CA_CAMCHANGE_* values.
+ */
+void dvb_ca_en50221_camchange_irq(struct dvb_ca_en50221 *pubca, int slot,
+				  int change_type)
+{
+	struct dvb_ca_private *ca = pubca->private;
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+
+	dprintk("CAMCHANGE IRQ slot:%i change_type:%i\n", slot, change_type);
+
+	switch (change_type) {
+	case DVB_CA_EN50221_CAMCHANGE_REMOVED:
+	case DVB_CA_EN50221_CAMCHANGE_INSERTED:
+		break;
+
+	default:
+		return;
+	}
+
+	sl->camchange_type = change_type;
+	atomic_inc(&sl->camchange_count);
+	dvb_ca_en50221_thread_wakeup(ca);
+}
+EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);
+
+/**
+ * dvb_ca_en50221_camready_irq - A CAMREADY IRQ has occurred.
+ *
+ * @pubca: CA instance.
+ * @slot: Slot concerned.
+ */
+void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 *pubca, int slot)
+{
+	struct dvb_ca_private *ca = pubca->private;
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+
+	dprintk("CAMREADY IRQ slot:%i\n", slot);
+
+	if (sl->slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
+		sl->slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+		dvb_ca_en50221_thread_wakeup(ca);
+	}
+}
+EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);
+
+/**
+ * dvb_ca_en50221_frda_irq - An FR or DA IRQ has occurred.
+ *
+ * @pubca: CA instance.
+ * @slot: Slot concerned.
+ */
+void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
+{
+	struct dvb_ca_private *ca = pubca->private;
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int flags;
+
+	dprintk("FR/DA IRQ slot:%i\n", slot);
+
+	switch (sl->slot_state) {
+	case DVB_CA_SLOTSTATE_LINKINIT:
+		flags = ca->pub->read_cam_control(pubca, slot, CTRLIF_STATUS);
+		if (flags & STATUSREG_DA) {
+			dprintk("CAM supports DA IRQ\n");
+			sl->da_irq_supported = 1;
+		}
+		break;
+
+	case DVB_CA_SLOTSTATE_RUNNING:
+		if (ca->open)
+			dvb_ca_en50221_thread_wakeup(ca);
+		break;
+	}
+}
+EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);
+
+/* ************************************************************************** */
+/* EN50221 thread functions */
+
+/**
+ * dvb_ca_en50221_thread_wakeup - Wake up the DVB CA thread
+ *
+ * @ca: CA instance.
+ */
+static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca)
+{
+	dprintk("%s\n", __func__);
+
+	ca->wakeup = 1;
+	mb();
+	wake_up_process(ca->thread);
+}
+
+/**
+ * dvb_ca_en50221_thread_update_delay - Update the delay used by the thread.
+ *
+ * @ca: CA instance.
+ */
+static void dvb_ca_en50221_thread_update_delay(struct dvb_ca_private *ca)
+{
+	int delay;
+	int curdelay = 100000000;
+	int slot;
+
+	/*
+	 * Beware of too high polling frequency, because one polling
+	 * call might take several hundred milliseconds until timeout!
+	 */
+	for (slot = 0; slot < ca->slot_count; slot++) {
+		struct dvb_ca_slot *sl = &ca->slot_info[slot];
+
+		switch (sl->slot_state) {
+		default:
+		case DVB_CA_SLOTSTATE_NONE:
+			delay = HZ * 60;  /* 60s */
+			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
+				delay = HZ * 5;  /* 5s */
+			break;
+		case DVB_CA_SLOTSTATE_INVALID:
+			delay = HZ * 60;  /* 60s */
+			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
+				delay = HZ / 10;  /* 100ms */
+			break;
+
+		case DVB_CA_SLOTSTATE_UNINITIALISED:
+		case DVB_CA_SLOTSTATE_WAITREADY:
+		case DVB_CA_SLOTSTATE_VALIDATE:
+		case DVB_CA_SLOTSTATE_WAITFR:
+		case DVB_CA_SLOTSTATE_LINKINIT:
+			delay = HZ / 10;  /* 100ms */
+			break;
+
+		case DVB_CA_SLOTSTATE_RUNNING:
+			delay = HZ * 60;  /* 60s */
+			if (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE))
+				delay = HZ / 10;  /* 100ms */
+			if (ca->open) {
+				if ((!sl->da_irq_supported) ||
+				    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA)))
+					delay = HZ / 10;  /* 100ms */
+			}
+			break;
+		}
+
+		if (delay < curdelay)
+			curdelay = delay;
+	}
+
+	ca->delay = curdelay;
+}
+
+/**
+ * dvb_ca_en50221_poll_cam_gone - Poll if the CAM is gone.
+ *
+ * @ca: CA instance.
+ * @slot: Slot to process.
+ * return:: 0 .. no change
+ *          1 .. CAM state changed
+ */
+
+static int dvb_ca_en50221_poll_cam_gone(struct dvb_ca_private *ca, int slot)
+{
+	int changed = 0;
+	int status;
+
+	/*
+	 * we need this extra check for annoying interfaces like the
+	 * budget-av
+	 */
+	if ((!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)) &&
+	    (ca->pub->poll_slot_status)) {
+		status = ca->pub->poll_slot_status(ca->pub, slot, 0);
+		if (!(status &
+			DVB_CA_EN50221_POLL_CAM_PRESENT)) {
+			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
+			dvb_ca_en50221_thread_update_delay(ca);
+			changed = 1;
+		}
+	}
+	return changed;
+}
+
+/**
+ * dvb_ca_en50221_thread_state_machine - Thread state machine for one CA slot
+ *	to perform the data transfer.
+ *
+ * @ca: CA instance.
+ * @slot: Slot to process.
+ */
+static void dvb_ca_en50221_thread_state_machine(struct dvb_ca_private *ca,
+						int slot)
+{
+	struct dvb_ca_slot *sl = &ca->slot_info[slot];
+	int flags;
+	int pktcount;
+	void *rxbuf;
+
+	mutex_lock(&sl->slot_lock);
+
+	/* check the cam status + deal with CAMCHANGEs */
+	while (dvb_ca_en50221_check_camstatus(ca, slot)) {
+		/* clear down an old CI slot if necessary */
+		if (sl->slot_state != DVB_CA_SLOTSTATE_NONE)
+			dvb_ca_en50221_slot_shutdown(ca, slot);
+
+		/* if a CAM is NOW present, initialise it */
+		if (sl->camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED)
+			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
+
+		/* we've handled one CAMCHANGE */
+		dvb_ca_en50221_thread_update_delay(ca);
+		atomic_dec(&sl->camchange_count);
+	}
+
+	/* CAM state machine */
+	switch (sl->slot_state) {
+	case DVB_CA_SLOTSTATE_NONE:
+	case DVB_CA_SLOTSTATE_INVALID:
+		/* no action needed */
+		break;
+
+	case DVB_CA_SLOTSTATE_UNINITIALISED:
+		sl->slot_state = DVB_CA_SLOTSTATE_WAITREADY;
+		ca->pub->slot_reset(ca->pub, slot);
+		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+		break;
+
+	case DVB_CA_SLOTSTATE_WAITREADY:
+		if (time_after(jiffies, sl->timeout)) {
+			pr_err("dvb_ca adaptor %d: PC card did not respond :(\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+		/*
+		 * no other action needed; will automatically change state when
+		 * ready
+		 */
+		break;
+
+	case DVB_CA_SLOTSTATE_VALIDATE:
+		if (dvb_ca_en50221_parse_attributes(ca, slot) != 0) {
+			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
+				break;
+
+			pr_err("dvb_ca adapter %d: Invalid PC card inserted :(\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+		if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
+			pr_err("dvb_ca adapter %d: Unable to initialise CAM :(\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+		if (ca->pub->write_cam_control(ca->pub, slot,
+					       CTRLIF_COMMAND,
+					       CMDREG_RS) != 0) {
+			pr_err("dvb_ca adapter %d: Unable to reset CAM IF\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+		dprintk("DVB CAM validated successfully\n");
+
+		sl->timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+		sl->slot_state = DVB_CA_SLOTSTATE_WAITFR;
+		ca->wakeup = 1;
+		break;
+
+	case DVB_CA_SLOTSTATE_WAITFR:
+		if (time_after(jiffies, sl->timeout)) {
+			pr_err("dvb_ca adapter %d: DVB CAM did not respond :(\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+
+		flags = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+		if (flags & STATUSREG_FR) {
+			sl->slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+			ca->wakeup = 1;
+		}
+		break;
+
+	case DVB_CA_SLOTSTATE_LINKINIT:
+		if (dvb_ca_en50221_link_init(ca, slot) != 0) {
+			if (dvb_ca_en50221_poll_cam_gone(ca, slot))
+				break;
+
+			pr_err("dvb_ca adapter %d: DVB CAM link initialisation failed :(\n",
+			       ca->dvbdev->adapter->num);
+			sl->slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
+			dvb_ca_en50221_thread_update_delay(ca);
+			break;
+		}
+
+		if (!sl->rx_buffer.data) {
+			rxbuf = vmalloc(RX_BUFFER_SIZE);
+			if (!rxbuf) {
+				pr_err("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n",
+				       ca->dvbdev->adapter->num);
+				sl->slot_state = DVB_CA_SLOTSTATE_INVALID;
+				dvb_ca_en50221_thread_update_delay(ca);
+				break;
+			}
+			dvb_ringbuffer_init(&sl->rx_buffer, rxbuf,
+					    RX_BUFFER_SIZE);
+		}
+
+		ca->pub->slot_ts_enable(ca->pub, slot);
+		sl->slot_state = DVB_CA_SLOTSTATE_RUNNING;
+		dvb_ca_en50221_thread_update_delay(ca);
+		pr_info("dvb_ca adapter %d: DVB CAM detected and initialised successfully\n",
+			ca->dvbdev->adapter->num);
+		break;
+
+	case DVB_CA_SLOTSTATE_RUNNING:
+		if (!ca->open)
+			break;
+
+		/* poll slots for data */
+		pktcount = 0;
+		while (dvb_ca_en50221_read_data(ca, slot, NULL, 0) > 0) {
+			if (!ca->open)
+				break;
+
+			/*
+			 * if a CAMCHANGE occurred at some point, do not do any
+			 * more processing of this slot
+			 */
+			if (dvb_ca_en50221_check_camstatus(ca, slot)) {
+				/*
+				 * we don't want to sleep on the next iteration
+				 * so we can handle the cam change
+				 */
+				ca->wakeup = 1;
+				break;
+			}
+
+			/* check if we've hit our limit this time */
+			if (++pktcount >= MAX_RX_PACKETS_PER_ITERATION) {
+				/*
+				 * don't sleep; there is likely to be more data
+				 * to read
+				 */
+				ca->wakeup = 1;
+				break;
+			}
+		}
+		break;
+	}
+
+	mutex_unlock(&sl->slot_lock);
+}
+
+/*
+ * Kernel thread which monitors CA slots for CAM changes, and performs data
+ * transfers.
+ */
+static int dvb_ca_en50221_thread(void *data)
+{
+	struct dvb_ca_private *ca = data;
+	int slot;
+
+	dprintk("%s\n", __func__);
+
+	/* choose the correct initial delay */
+	dvb_ca_en50221_thread_update_delay(ca);
+
+	/* main loop */
+	while (!kthread_should_stop()) {
+		/* sleep for a bit */
+		if (!ca->wakeup) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(ca->delay);
+			if (kthread_should_stop())
+				return 0;
+		}
+		ca->wakeup = 0;
+
+		/* go through all the slots processing them */
+		for (slot = 0; slot < ca->slot_count; slot++)
+			dvb_ca_en50221_thread_state_machine(ca, slot);
+	}
+
+	return 0;
+}
+
+/* ************************************************************************** */
+/* EN50221 IO interface functions */
+
+/**
+ * dvb_ca_en50221_io_do_ioctl - Real ioctl implementation.
+ *
+ * @file: File concerned.
+ * @cmd: IOCTL command.
+ * @parg: Associated argument.
+ *
+ * NOTE: CA_SEND_MSG/CA_GET_MSG ioctls have userspace buffers passed to them.
+ *
+ * return: 0 on success, <0 on error.
+ */
+static int dvb_ca_en50221_io_do_ioctl(struct file *file,
+				      unsigned int cmd, void *parg)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	int err = 0;
+	int slot;
+
+	dprintk("%s\n", __func__);
+
+	if (mutex_lock_interruptible(&ca->ioctl_mutex))
+		return -ERESTARTSYS;
+
+	switch (cmd) {
+	case CA_RESET:
+		for (slot = 0; slot < ca->slot_count; slot++) {
+			struct dvb_ca_slot *sl = &ca->slot_info[slot];
+
+			mutex_lock(&sl->slot_lock);
+			if (sl->slot_state != DVB_CA_SLOTSTATE_NONE) {
+				dvb_ca_en50221_slot_shutdown(ca, slot);
+				if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE)
+					dvb_ca_en50221_camchange_irq(ca->pub,
+								     slot,
+								     DVB_CA_EN50221_CAMCHANGE_INSERTED);
+			}
+			mutex_unlock(&sl->slot_lock);
+		}
+		ca->next_read_slot = 0;
+		dvb_ca_en50221_thread_wakeup(ca);
+		break;
+
+	case CA_GET_CAP: {
+		struct ca_caps *caps = parg;
+
+		caps->slot_num = ca->slot_count;
+		caps->slot_type = CA_CI_LINK;
+		caps->descr_num = 0;
+		caps->descr_type = 0;
+		break;
+	}
+
+	case CA_GET_SLOT_INFO: {
+		struct ca_slot_info *info = parg;
+		struct dvb_ca_slot *sl;
+
+		slot = info->num;
+		if ((slot >= ca->slot_count) || (slot < 0)) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+		slot = array_index_nospec(slot, ca->slot_count);
+
+		info->type = CA_CI_LINK;
+		info->flags = 0;
+		sl = &ca->slot_info[slot];
+		if ((sl->slot_state != DVB_CA_SLOTSTATE_NONE) &&
+		    (sl->slot_state != DVB_CA_SLOTSTATE_INVALID)) {
+			info->flags = CA_CI_MODULE_PRESENT;
+		}
+		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING)
+			info->flags |= CA_CI_MODULE_READY;
+		break;
+	}
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+out_unlock:
+	mutex_unlock(&ca->ioctl_mutex);
+	return err;
+}
+
+/**
+ * dvb_ca_en50221_io_ioctl - Wrapper for ioctl implementation.
+ *
+ * @file: File concerned.
+ * @cmd: IOCTL command.
+ * @arg: Associated argument.
+ *
+ * return: 0 on success, <0 on error.
+ */
+static long dvb_ca_en50221_io_ioctl(struct file *file,
+				    unsigned int cmd, unsigned long arg)
+{
+	return dvb_usercopy(file, cmd, arg, dvb_ca_en50221_io_do_ioctl);
+}
+
+/**
+ * dvb_ca_en50221_io_write - Implementation of write() syscall.
+ *
+ * @file: File structure.
+ * @buf: Source buffer.
+ * @count: Size of source buffer.
+ * @ppos: Position in file (ignored).
+ *
+ * return: Number of bytes read, or <0 on error.
+ */
+static ssize_t dvb_ca_en50221_io_write(struct file *file,
+				       const char __user *buf, size_t count,
+				       loff_t *ppos)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	struct dvb_ca_slot *sl;
+	u8 slot, connection_id;
+	int status;
+	u8 fragbuf[HOST_LINK_BUF_SIZE];
+	int fragpos = 0;
+	int fraglen;
+	unsigned long timeout;
+	int written;
+
+	dprintk("%s\n", __func__);
+
+	/*
+	 * Incoming packet has a 2 byte header.
+	 * hdr[0] = slot_id, hdr[1] = connection_id
+	 */
+	if (count < 2)
+		return -EINVAL;
+
+	/* extract slot & connection id */
+	if (copy_from_user(&slot, buf, 1))
+		return -EFAULT;
+	if (copy_from_user(&connection_id, buf + 1, 1))
+		return -EFAULT;
+	buf += 2;
+	count -= 2;
+
+	if (slot >= ca->slot_count)
+		return -EINVAL;
+	slot = array_index_nospec(slot, ca->slot_count);
+	sl = &ca->slot_info[slot];
+
+	/* check if the slot is actually running */
+	if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
+		return -EINVAL;
+
+	/* fragment the packets & store in the buffer */
+	while (fragpos < count) {
+		fraglen = sl->link_buf_size - 2;
+		if (fraglen < 0)
+			break;
+		if (fraglen > HOST_LINK_BUF_SIZE - 2)
+			fraglen = HOST_LINK_BUF_SIZE - 2;
+		if ((count - fragpos) < fraglen)
+			fraglen = count - fragpos;
+
+		fragbuf[0] = connection_id;
+		fragbuf[1] = ((fragpos + fraglen) < count) ? 0x80 : 0x00;
+		status = copy_from_user(fragbuf + 2, buf + fragpos, fraglen);
+		if (status) {
+			status = -EFAULT;
+			goto exit;
+		}
+
+		timeout = jiffies + HZ / 2;
+		written = 0;
+		while (!time_after(jiffies, timeout)) {
+			/*
+			 * check the CAM hasn't been removed/reset in the
+			 * meantime
+			 */
+			if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING) {
+				status = -EIO;
+				goto exit;
+			}
+
+			mutex_lock(&sl->slot_lock);
+			status = dvb_ca_en50221_write_data(ca, slot, fragbuf,
+							   fraglen + 2);
+			mutex_unlock(&sl->slot_lock);
+			if (status == (fraglen + 2)) {
+				written = 1;
+				break;
+			}
+			if (status != -EAGAIN)
+				goto exit;
+
+			usleep_range(1000, 1100);
+		}
+		if (!written) {
+			status = -EIO;
+			goto exit;
+		}
+
+		fragpos += fraglen;
+	}
+	status = count + 2;
+
+exit:
+	return status;
+}
+
+/*
+ * Condition for waking up in dvb_ca_en50221_io_read_condition
+ */
+static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
+					    int *result, int *_slot)
+{
+	int slot;
+	int slot_count = 0;
+	int idx;
+	size_t fraglen;
+	int connection_id = -1;
+	int found = 0;
+	u8 hdr[2];
+
+	slot = ca->next_read_slot;
+	while ((slot_count < ca->slot_count) && (!found)) {
+		struct dvb_ca_slot *sl = &ca->slot_info[slot];
+
+		if (sl->slot_state != DVB_CA_SLOTSTATE_RUNNING)
+			goto nextslot;
+
+		if (!sl->rx_buffer.data)
+			return 0;
+
+		idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
+		while (idx != -1) {
+			dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
+			if (connection_id == -1)
+				connection_id = hdr[0];
+			if ((hdr[0] == connection_id) &&
+			    ((hdr[1] & 0x80) == 0)) {
+				*_slot = slot;
+				found = 1;
+				break;
+			}
+
+			idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx,
+						      &fraglen);
+		}
+
+nextslot:
+		slot = (slot + 1) % ca->slot_count;
+		slot_count++;
+	}
+
+	ca->next_read_slot = slot;
+	return found;
+}
+
+/**
+ * dvb_ca_en50221_io_read - Implementation of read() syscall.
+ *
+ * @file: File structure.
+ * @buf: Destination buffer.
+ * @count: Size of destination buffer.
+ * @ppos: Position in file (ignored).
+ *
+ * return: Number of bytes read, or <0 on error.
+ */
+static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user *buf,
+				      size_t count, loff_t *ppos)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	struct dvb_ca_slot *sl;
+	int status;
+	int result = 0;
+	u8 hdr[2];
+	int slot;
+	int connection_id = -1;
+	size_t idx, idx2;
+	int last_fragment = 0;
+	size_t fraglen;
+	int pktlen;
+	int dispose = 0;
+
+	dprintk("%s\n", __func__);
+
+	/*
+	 * Outgoing packet has a 2 byte header.
+	 * hdr[0] = slot_id, hdr[1] = connection_id
+	 */
+	if (count < 2)
+		return -EINVAL;
+
+	/* wait for some data */
+	status = dvb_ca_en50221_io_read_condition(ca, &result, &slot);
+	if (status == 0) {
+		/* if we're in nonblocking mode, exit immediately */
+		if (file->f_flags & O_NONBLOCK)
+			return -EWOULDBLOCK;
+
+		/* wait for some data */
+		status = wait_event_interruptible(ca->wait_queue,
+						  dvb_ca_en50221_io_read_condition
+						  (ca, &result, &slot));
+	}
+	if ((status < 0) || (result < 0)) {
+		if (result)
+			return result;
+		return status;
+	}
+
+	sl = &ca->slot_info[slot];
+	idx = dvb_ringbuffer_pkt_next(&sl->rx_buffer, -1, &fraglen);
+	pktlen = 2;
+	do {
+		if (idx == -1) {
+			pr_err("dvb_ca adapter %d: BUG: read packet ended before last_fragment encountered\n",
+			       ca->dvbdev->adapter->num);
+			status = -EIO;
+			goto exit;
+		}
+
+		dvb_ringbuffer_pkt_read(&sl->rx_buffer, idx, 0, hdr, 2);
+		if (connection_id == -1)
+			connection_id = hdr[0];
+		if (hdr[0] == connection_id) {
+			if (pktlen < count) {
+				if ((pktlen + fraglen - 2) > count)
+					fraglen = count - pktlen;
+				else
+					fraglen -= 2;
+
+				status =
+				   dvb_ringbuffer_pkt_read_user(&sl->rx_buffer,
+								idx, 2,
+								buf + pktlen,
+								fraglen);
+				if (status < 0)
+					goto exit;
+
+				pktlen += fraglen;
+			}
+
+			if ((hdr[1] & 0x80) == 0)
+				last_fragment = 1;
+			dispose = 1;
+		}
+
+		idx2 = dvb_ringbuffer_pkt_next(&sl->rx_buffer, idx, &fraglen);
+		if (dispose)
+			dvb_ringbuffer_pkt_dispose(&sl->rx_buffer, idx);
+		idx = idx2;
+		dispose = 0;
+	} while (!last_fragment);
+
+	hdr[0] = slot;
+	hdr[1] = connection_id;
+	status = copy_to_user(buf, hdr, 2);
+	if (status) {
+		status = -EFAULT;
+		goto exit;
+	}
+	status = pktlen;
+
+exit:
+	return status;
+}
+
+/**
+ * dvb_ca_en50221_io_open - Implementation of file open syscall.
+ *
+ * @inode: Inode concerned.
+ * @file: File concerned.
+ *
+ * return: 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	int err;
+	int i;
+
+	dprintk("%s\n", __func__);
+
+	if (!try_module_get(ca->pub->owner))
+		return -EIO;
+
+	err = dvb_generic_open(inode, file);
+	if (err < 0) {
+		module_put(ca->pub->owner);
+		return err;
+	}
+
+	for (i = 0; i < ca->slot_count; i++) {
+		struct dvb_ca_slot *sl = &ca->slot_info[i];
+
+		if (sl->slot_state == DVB_CA_SLOTSTATE_RUNNING) {
+			if (!sl->rx_buffer.data) {
+				/*
+				 * it is safe to call this here without locks
+				 * because ca->open == 0. Data is not read in
+				 * this case
+				 */
+				dvb_ringbuffer_flush(&sl->rx_buffer);
+			}
+		}
+	}
+
+	ca->open = 1;
+	dvb_ca_en50221_thread_update_delay(ca);
+	dvb_ca_en50221_thread_wakeup(ca);
+
+	dvb_ca_private_get(ca);
+
+	return 0;
+}
+
+/**
+ * dvb_ca_en50221_io_release - Implementation of file close syscall.
+ *
+ * @inode: Inode concerned.
+ * @file: File concerned.
+ *
+ * return: 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_io_release(struct inode *inode, struct file *file)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	int err;
+
+	dprintk("%s\n", __func__);
+
+	/* mark the CA device as closed */
+	ca->open = 0;
+	dvb_ca_en50221_thread_update_delay(ca);
+
+	err = dvb_generic_release(inode, file);
+
+	module_put(ca->pub->owner);
+
+	dvb_ca_private_put(ca);
+
+	return err;
+}
+
+/**
+ * dvb_ca_en50221_io_poll - Implementation of poll() syscall.
+ *
+ * @file: File concerned.
+ * @wait: poll wait table.
+ *
+ * return: Standard poll mask.
+ */
+static __poll_t dvb_ca_en50221_io_poll(struct file *file, poll_table *wait)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_ca_private *ca = dvbdev->priv;
+	__poll_t mask = 0;
+	int slot;
+	int result = 0;
+
+	dprintk("%s\n", __func__);
+
+	poll_wait(file, &ca->wait_queue, wait);
+
+	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
+		mask |= EPOLLIN;
+
+	/* if there is something, return now */
+	if (mask)
+		return mask;
+
+	if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1)
+		mask |= EPOLLIN;
+
+	return mask;
+}
+
+static const struct file_operations dvb_ca_fops = {
+	.owner = THIS_MODULE,
+	.read = dvb_ca_en50221_io_read,
+	.write = dvb_ca_en50221_io_write,
+	.unlocked_ioctl = dvb_ca_en50221_io_ioctl,
+	.open = dvb_ca_en50221_io_open,
+	.release = dvb_ca_en50221_io_release,
+	.poll = dvb_ca_en50221_io_poll,
+	.llseek = noop_llseek,
+};
+
+static const struct dvb_device dvbdev_ca = {
+	.priv = NULL,
+	.users = 1,
+	.readers = 1,
+	.writers = 1,
+#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
+	.name = "dvb-ca-en50221",
+#endif
+	.fops = &dvb_ca_fops,
+};
+
+/* ************************************************************************** */
+/* Initialisation/shutdown functions */
+
+/**
+ * dvb_ca_en50221_init - Initialise a new DVB CA EN50221 interface device.
+ *
+ * @dvb_adapter: DVB adapter to attach the new CA device to.
+ * @pubca: The dvb_ca instance.
+ * @flags: Flags describing the CA device (DVB_CA_FLAG_*).
+ * @slot_count: Number of slots supported.
+ *
+ * return: 0 on success, nonzero on failure
+ */
+int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
+			struct dvb_ca_en50221 *pubca, int flags, int slot_count)
+{
+	int ret;
+	struct dvb_ca_private *ca = NULL;
+	int i;
+
+	dprintk("%s\n", __func__);
+
+	if (slot_count < 1)
+		return -EINVAL;
+
+	/* initialise the system data */
+	ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+	if (!ca) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	kref_init(&ca->refcount);
+	ca->pub = pubca;
+	ca->flags = flags;
+	ca->slot_count = slot_count;
+	ca->slot_info = kcalloc(slot_count, sizeof(struct dvb_ca_slot),
+				GFP_KERNEL);
+	if (!ca->slot_info) {
+		ret = -ENOMEM;
+		goto free_ca;
+	}
+	init_waitqueue_head(&ca->wait_queue);
+	ca->open = 0;
+	ca->wakeup = 0;
+	ca->next_read_slot = 0;
+	pubca->private = ca;
+
+	/* register the DVB device */
+	ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca,
+				  DVB_DEVICE_CA, 0);
+	if (ret)
+		goto free_slot_info;
+
+	/* now initialise each slot */
+	for (i = 0; i < slot_count; i++) {
+		struct dvb_ca_slot *sl = &ca->slot_info[i];
+
+		memset(sl, 0, sizeof(struct dvb_ca_slot));
+		sl->slot_state = DVB_CA_SLOTSTATE_NONE;
+		atomic_set(&sl->camchange_count, 0);
+		sl->camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
+		mutex_init(&sl->slot_lock);
+	}
+
+	mutex_init(&ca->ioctl_mutex);
+
+	if (signal_pending(current)) {
+		ret = -EINTR;
+		goto unregister_device;
+	}
+	mb();
+
+	/* create a kthread for monitoring this CA device */
+	ca->thread = kthread_run(dvb_ca_en50221_thread, ca, "kdvb-ca-%i:%i",
+				 ca->dvbdev->adapter->num, ca->dvbdev->id);
+	if (IS_ERR(ca->thread)) {
+		ret = PTR_ERR(ca->thread);
+		pr_err("dvb_ca_init: failed to start kernel_thread (%d)\n",
+		       ret);
+		goto unregister_device;
+	}
+	return 0;
+
+unregister_device:
+	dvb_unregister_device(ca->dvbdev);
+free_slot_info:
+	kfree(ca->slot_info);
+free_ca:
+	kfree(ca);
+exit:
+	pubca->private = NULL;
+	return ret;
+}
+EXPORT_SYMBOL(dvb_ca_en50221_init);
+
+/**
+ * dvb_ca_en50221_release - Release a DVB CA EN50221 interface device.
+ *
+ * @pubca: The associated dvb_ca instance.
+ */
+void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
+{
+	struct dvb_ca_private *ca = pubca->private;
+	int i;
+
+	dprintk("%s\n", __func__);
+
+	/* shutdown the thread if there was one */
+	kthread_stop(ca->thread);
+
+	for (i = 0; i < ca->slot_count; i++)
+		dvb_ca_en50221_slot_shutdown(ca, i);
+
+	dvb_remove_device(ca->dvbdev);
+	dvb_ca_private_put(ca);
+	pubca->private = NULL;
+}
+EXPORT_SYMBOL(dvb_ca_en50221_release);