[media] dvb: move the dvb core one level up

just like the V4L2 core, move the DVB core to drivers/media, as the
intention is to get rid of both "video" and "dvb" directories.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 1753 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 000000000000..9be65a3b931f
--- /dev/null
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -0,0 +1,1753 @@
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * Or, point your browser to http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/kthread.h>
+
+#include "dvb_ca_en50221.h"
+#include "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 if (dvb_ca_en50221_debug) printk
+
+#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 STATUSREG_TXERR (STATUSREG_RE|STATUSREG_WE)	/* general transfer error */
+
+
+#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 {
+
+	/* 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;
+};
+
+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);
+
+
+/**
+ * Safely find needle in haystack.
+ *
+ * @param haystack Buffer to look in.
+ * @param hlen Number of bytes in haystack.
+ * @param needle Buffer to find.
+ * @param 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 */
+
+
+/**
+ * Check CAM status.
+ */
+static int dvb_ca_en50221_check_camstatus(struct dvb_ca_private *ca, int 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(&ca->slot_info[slot].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 = (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE);
+		cam_changed = (cam_present_now != cam_present_old);
+	}
+
+	if (cam_changed) {
+		if (!cam_present_now) {
+			ca->slot_info[slot].camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED;
+		} else {
+			ca->slot_info[slot].camchange_type = DVB_CA_EN50221_CAMCHANGE_INSERTED;
+		}
+		atomic_set(&ca->slot_info[slot].camchange_count, 1);
+	} else {
+		if ((ca->slot_info[slot].slot_state == DVB_CA_SLOTSTATE_WAITREADY) &&
+		    (slot_status & DVB_CA_EN50221_POLL_CAM_READY)) {
+			// move to validate state if reset is completed
+			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+		}
+	}
+
+	return cam_changed;
+}
+
+
+/**
+ * Wait for flags to become set on the STATUS register on a CAM interface,
+ * checking for errors and timeout.
+ *
+ * @param ca CA instance.
+ * @param slot Slot on interface.
+ * @param waitfor Flags to wait for.
+ * @param timeout_ms 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) {
+		/* read the status and check for error */
+		int 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 */
+		msleep(1);
+	}
+
+	dprintk("%s failed timeout:%lu\n", __func__, jiffies - start);
+
+	/* if we get here, we've timed out */
+	return -ETIMEDOUT;
+}
+
+
+/**
+ * Initialise the link layer connection to a CAM.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ *
+ * @return 0 on success, nonzero on failure.
+ */
+static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot)
+{
+	int ret;
+	int buf_size;
+	u8 buf[2];
+
+	dprintk("%s\n", __func__);
+
+	/* we'll be determining these during this function */
+	ca->slot_info[slot].da_irq_supported = 0;
+
+	/* set the host link buffer size temporarily. it will be overwritten with the
+	 * real negotiated size later. */
+	ca->slot_info[slot].link_buf_size = 2;
+
+	/* read the buffer size from the CAM */
+	if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN | CMDREG_SR)) != 0)
+		return ret;
+	if ((ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_DA, HZ / 10)) != 0)
+		return ret;
+	if ((ret = dvb_ca_en50221_read_data(ca, slot, buf, 2)) != 2)
+		return -EIO;
+	if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN)) != 0)
+		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;
+	ca->slot_info[slot].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 */
+	if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN | CMDREG_SW)) != 0)
+		return ret;
+	if ((ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10)) != 0)
+		return ret;
+	if ((ret = dvb_ca_en50221_write_data(ca, slot, buf, 2)) != 2)
+		return -EIO;
+	if ((ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN)) != 0)
+		return ret;
+
+	/* success */
+	return 0;
+}
+
+/**
+ * Read a tuple from attribute memory.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ * @param address Address to read from. Updated.
+ * @param tupleType Tuple id byte. Updated.
+ * @param tupleLength Tuple length. Updated.
+ * @param 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 *tupleType, int *tupleLength, u8 * tuple)
+{
+	int i;
+	int _tupleType;
+	int _tupleLength;
+	int _address = *address;
+
+	/* grab the next tuple length and type */
+	if ((_tupleType = ca->pub->read_attribute_mem(ca->pub, slot, _address)) < 0)
+		return _tupleType;
+	if (_tupleType == 0xff) {
+		dprintk("END OF CHAIN TUPLE type:0x%x\n", _tupleType);
+		*address += 2;
+		*tupleType = _tupleType;
+		*tupleLength = 0;
+		return 0;
+	}
+	if ((_tupleLength = ca->pub->read_attribute_mem(ca->pub, slot, _address + 2)) < 0)
+		return _tupleLength;
+	_address += 4;
+
+	dprintk("TUPLE type:0x%x length:%i\n", _tupleType, _tupleLength);
+
+	/* read in the whole tuple */
+	for (i = 0; i < _tupleLength; 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 += (_tupleLength * 2);
+
+	// success
+	*tupleType = _tupleType;
+	*tupleLength = _tupleLength;
+	*address = _address;
+	return 0;
+}
+
+
+/**
+ * Parse attribute memory of a CAM module, extracting Config register, and checking
+ * it is a DVB CAM module.
+ *
+ * @param ca CA instance.
+ * @param slot Slot id.
+ *
+ * @return 0 on success, <0 on failure.
+ */
+static int dvb_ca_en50221_parse_attributes(struct dvb_ca_private *ca, int slot)
+{
+	int address = 0;
+	int tupleLength;
+	int tupleType;
+	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
+	if ((status =
+	     dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0)
+		return status;
+	if (tupleType != 0x1D)
+		return -EINVAL;
+
+
+
+	// CISTPL_DEVICE_0C
+	if ((status =
+	     dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0)
+		return status;
+	if (tupleType != 0x1C)
+		return -EINVAL;
+
+
+
+	// CISTPL_VERS_1
+	if ((status =
+	     dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType, &tupleLength, tuple)) < 0)
+		return status;
+	if (tupleType != 0x15)
+		return -EINVAL;
+
+
+
+	// CISTPL_MANFID
+	if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType,
+						&tupleLength, tuple)) < 0)
+		return status;
+	if (tupleType != 0x20)
+		return -EINVAL;
+	if (tupleLength != 4)
+		return -EINVAL;
+	manfid = (tuple[1] << 8) | tuple[0];
+	devid = (tuple[3] << 8) | tuple[2];
+
+
+
+	// CISTPL_CONFIG
+	if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType,
+						&tupleLength, tuple)) < 0)
+		return status;
+	if (tupleType != 0x1A)
+		return -EINVAL;
+	if (tupleLength < 3)
+		return -EINVAL;
+
+	/* extract the configbase */
+	rasz = tuple[0] & 3;
+	if (tupleLength < (3 + rasz + 14))
+		return -EINVAL;
+	ca->slot_info[slot].config_base = 0;
+	for (i = 0; i < rasz + 1; i++) {
+		ca->slot_info[slot].config_base |= (tuple[2 + i] << (8 * i));
+	}
+
+	/* check it contains the correct DVB string */
+	dvb_str = findstr((char *)tuple, tupleLength, "DVB_CI_V", 8);
+	if (dvb_str == NULL)
+		return -EINVAL;
+	if (tupleLength < ((dvb_str - (char *) tuple) + 12))
+		return -EINVAL;
+
+	/* is it a version we support? */
+	if (strncmp(dvb_str + 8, "1.00", 4)) {
+		printk("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)) {
+		if ((status = dvb_ca_en50221_read_tuple(ca, slot, &address, &tupleType,
+							&tupleLength, tuple)) < 0)
+			return status;
+		switch (tupleType) {
+		case 0x1B:	// CISTPL_CFTABLE_ENTRY
+			if (tupleLength < (2 + 11 + 17))
+				break;
+
+			/* if we've already parsed one, just use it */
+			if (got_cftableentry)
+				break;
+
+			/* get the config option */
+			ca->slot_info[slot].config_option = tuple[0] & 0x3f;
+
+			/* OK, check it contains the correct strings */
+			if ((findstr((char *)tuple, tupleLength, "DVB_HOST", 8) == NULL) ||
+			    (findstr((char *)tuple, tupleLength, "DVB_CI_MODULE", 13) == NULL))
+				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 and move to the next one */
+			dprintk("dvb_ca: Skipping unknown tuple type:0x%x length:0x%x\n", tupleType,
+				tupleLength);
+			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, ca->slot_info[slot].config_base, ca->slot_info[slot].config_option);
+
+	// success!
+	return 0;
+}
+
+
+/**
+ * Set CAM's configoption correctly.
+ *
+ * @param ca CA instance.
+ * @param slot Slot containing the CAM.
+ */
+static int dvb_ca_en50221_set_configoption(struct dvb_ca_private *ca, int slot)
+{
+	int configoption;
+
+	dprintk("%s\n", __func__);
+
+	/* set the config option */
+	ca->pub->write_attribute_mem(ca->pub, slot,
+				     ca->slot_info[slot].config_base,
+				     ca->slot_info[slot].config_option);
+
+	/* check it */
+	configoption = ca->pub->read_attribute_mem(ca->pub, slot, ca->slot_info[slot].config_base);
+	dprintk("Set configoption 0x%x, read configoption 0x%x\n",
+		ca->slot_info[slot].config_option, configoption & 0x3f);
+
+	/* fine! */
+	return 0;
+
+}
+
+
+/**
+ * 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.
+ *
+ * @param ca CA instance.
+ * @param slot Slot to read from.
+ * @param 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.
+ * @param 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)
+{
+	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 == NULL) {
+		int buf_free;
+
+		if (ca->slot_info[slot].rx_buffer.data == NULL) {
+			status = -EIO;
+			goto exit;
+		}
+		buf_free = dvb_ringbuffer_free(&ca->slot_info[slot].rx_buffer);
+
+		if (buf_free < (ca->slot_info[slot].link_buf_size + DVB_RINGBUFFER_PKTHDRSIZE)) {
+			status = -EAGAIN;
+			goto exit;
+		}
+	}
+
+	/* check if there is data available */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0)
+		goto exit;
+	if (!(status & STATUSREG_DA)) {
+		/* no data */
+		status = 0;
+		goto exit;
+	}
+
+	/* read the amount of data */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH)) < 0)
+		goto exit;
+	bytes_read = status << 8;
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW)) < 0)
+		goto exit;
+	bytes_read |= status;
+
+	/* check it will fit */
+	if (ebuf == NULL) {
+		if (bytes_read > ca->slot_info[slot].link_buf_size) {
+			printk("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, ca->slot_info[slot].link_buf_size);
+			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+			status = -EIO;
+			goto exit;
+		}
+		if (bytes_read < 2) {
+			printk("dvb_ca adapter %d: CAM sent a buffer that was less than 2 bytes!\n",
+			       ca->dvbdev->adapter->num);
+			ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+			status = -EIO;
+			goto exit;
+		}
+	} else {
+		if (bytes_read > ecount) {
+			printk("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 */
+		if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_DATA)) < 0)
+			goto exit;
+
+		/* OK, store it in the buffer */
+		buf[i] = status;
+	}
+
+	/* check for read error (RE should now be 0) */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0)
+		goto exit;
+	if (status & STATUSREG_RE) {
+		ca->slot_info[slot].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 == NULL) {
+		if (ca->slot_info[slot].rx_buffer.data == NULL) {
+			status = -EIO;
+			goto exit;
+		}
+		dvb_ringbuffer_pkt_write(&ca->slot_info[slot].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;
+}
+
+
+/**
+ * This function talks to an EN50221 CAM control interface. It writes a buffer of data
+ * to a CAM.
+ *
+ * @param ca CA instance.
+ * @param slot Slot to write to.
+ * @param ebuf The data in this buffer is treated as a complete link-level packet to
+ * be written.
+ * @param count 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)
+{
+	int status;
+	int i;
+
+	dprintk("%s\n", __func__);
+
+
+	/* sanity check */
+	if (bytes_write > ca->slot_info[slot].link_buf_size)
+		return -EINVAL;
+
+	/* 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. */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_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 */
+	if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND,
+						 IRQEN | CMDREG_HC)) != 0)
+		goto exit;
+
+	/* check if interface is still free */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0)
+		goto exit;
+	if (!(status & STATUSREG_FR)) {
+		/* it wasn't free => try again later */
+		status = -EAGAIN;
+		goto exit;
+	}
+
+	/* send the amount of data */
+	if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH, bytes_write >> 8)) != 0)
+		goto exit;
+	if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_LOW,
+						 bytes_write & 0xff)) != 0)
+		goto exit;
+
+	/* send the buffer */
+	for (i = 0; i < bytes_write; i++) {
+		if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_DATA, buf[i])) != 0)
+			goto exit;
+	}
+
+	/* check for write error (WE should now be 0) */
+	if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0)
+		goto exit;
+	if (status & STATUSREG_WE) {
+		ca->slot_info[slot].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;
+}
+EXPORT_SYMBOL(dvb_ca_en50221_camchange_irq);
+
+
+
+/* ******************************************************************************** */
+/* EN50221 higher level functions */
+
+
+/**
+ * A CAM has been removed => shut it down.
+ *
+ * @param ca CA instance.
+ * @param 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;
+}
+EXPORT_SYMBOL(dvb_ca_en50221_camready_irq);
+
+
+/**
+ * A CAMCHANGE IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ * @param 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;
+
+	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;
+	}
+
+	ca->slot_info[slot].camchange_type = change_type;
+	atomic_inc(&ca->slot_info[slot].camchange_count);
+	dvb_ca_en50221_thread_wakeup(ca);
+}
+EXPORT_SYMBOL(dvb_ca_en50221_frda_irq);
+
+
+/**
+ * A CAMREADY IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_camready_irq(struct dvb_ca_en50221 *pubca, int slot)
+{
+	struct dvb_ca_private *ca = pubca->private;
+
+	dprintk("CAMREADY IRQ slot:%i\n", slot);
+
+	if (ca->slot_info[slot].slot_state == DVB_CA_SLOTSTATE_WAITREADY) {
+		ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_VALIDATE;
+		dvb_ca_en50221_thread_wakeup(ca);
+	}
+}
+
+
+/**
+ * An FR or DA IRQ has occurred.
+ *
+ * @param ca CA instance.
+ * @param slot Slot concerned.
+ */
+void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
+{
+	struct dvb_ca_private *ca = pubca->private;
+	int flags;
+
+	dprintk("FR/DA IRQ slot:%i\n", slot);
+
+	switch (ca->slot_info[slot].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");
+			ca->slot_info[slot].da_irq_supported = 1;
+		}
+		break;
+
+	case DVB_CA_SLOTSTATE_RUNNING:
+		if (ca->open)
+			dvb_ca_en50221_thread_wakeup(ca);
+		break;
+	}
+}
+
+
+
+/* ******************************************************************************** */
+/* EN50221 thread functions */
+
+/**
+ * Wake up the DVB CA thread
+ *
+ * @param 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);
+}
+
+/**
+ * Update the delay used by the thread.
+ *
+ * @param 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++) {
+		switch (ca->slot_info[slot].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 ((!ca->slot_info[slot].da_irq_supported) ||
+				    (!(ca->flags & DVB_CA_EN50221_FLAG_IRQ_DA)))
+					delay = HZ / 10;  /* 100ms */
+			}
+			break;
+		}
+
+		if (delay < curdelay)
+			curdelay = delay;
+	}
+
+	ca->delay = curdelay;
+}
+
+
+
+/**
+ * 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;
+	int flags;
+	int status;
+	int pktcount;
+	void *rxbuf;
+
+	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++) {
+
+			mutex_lock(&ca->slot_info[slot].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 (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE)
+					dvb_ca_en50221_slot_shutdown(ca, slot);
+
+				/* if a CAM is NOW present, initialise it */
+				if (ca->slot_info[slot].camchange_type == DVB_CA_EN50221_CAMCHANGE_INSERTED) {
+					ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_UNINITIALISED;
+				}
+
+				/* we've handled one CAMCHANGE */
+				dvb_ca_en50221_thread_update_delay(ca);
+				atomic_dec(&ca->slot_info[slot].camchange_count);
+			}
+
+			// CAM state machine
+			switch (ca->slot_info[slot].slot_state) {
+			case DVB_CA_SLOTSTATE_NONE:
+			case DVB_CA_SLOTSTATE_INVALID:
+				// no action needed
+				break;
+
+			case DVB_CA_SLOTSTATE_UNINITIALISED:
+				ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_WAITREADY;
+				ca->pub->slot_reset(ca->pub, slot);
+				ca->slot_info[slot].timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+				break;
+
+			case DVB_CA_SLOTSTATE_WAITREADY:
+				if (time_after(jiffies, ca->slot_info[slot].timeout)) {
+					printk("dvb_ca adaptor %d: PC card did not respond :(\n",
+					       ca->dvbdev->adapter->num);
+					ca->slot_info[slot].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) {
+					/* 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);
+							break;
+						}
+					}
+
+					printk("dvb_ca adapter %d: Invalid PC card inserted :(\n",
+					       ca->dvbdev->adapter->num);
+					ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+					dvb_ca_en50221_thread_update_delay(ca);
+					break;
+				}
+				if (dvb_ca_en50221_set_configoption(ca, slot) != 0) {
+					printk("dvb_ca adapter %d: Unable to initialise CAM :(\n",
+					       ca->dvbdev->adapter->num);
+					ca->slot_info[slot].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) {
+					printk("dvb_ca adapter %d: Unable to reset CAM IF\n",
+					       ca->dvbdev->adapter->num);
+					ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+					dvb_ca_en50221_thread_update_delay(ca);
+					break;
+				}
+				dprintk("DVB CAM validated successfully\n");
+
+				ca->slot_info[slot].timeout = jiffies + (INIT_TIMEOUT_SECS * HZ);
+				ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_WAITFR;
+				ca->wakeup = 1;
+				break;
+
+			case DVB_CA_SLOTSTATE_WAITFR:
+				if (time_after(jiffies, ca->slot_info[slot].timeout)) {
+					printk("dvb_ca adapter %d: DVB CAM did not respond :(\n",
+					       ca->dvbdev->adapter->num);
+					ca->slot_info[slot].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) {
+					ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_LINKINIT;
+					ca->wakeup = 1;
+				}
+				break;
+
+			case DVB_CA_SLOTSTATE_LINKINIT:
+				if (dvb_ca_en50221_link_init(ca, slot) != 0) {
+					/* 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);
+							break;
+						}
+					}
+
+					printk("dvb_ca adapter %d: DVB CAM link initialisation failed :(\n", ca->dvbdev->adapter->num);
+					ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
+					dvb_ca_en50221_thread_update_delay(ca);
+					brea