dvb_ca_en50221.c

Linux dvb-ci apifor use as an example

/*
 * 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 <[e-mail]>
 *
 * 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/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/sched.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;

	/* 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 */
	pid_t thread_pid;

	/* Wait queue used when shutting thread down */
	wait_queue_head_t thread_queue;

	/* Flag indicating when thread should exit */
	unsigned int exit:1;

	/* 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 u8 *findstr(u8 * haystack, int hlen, u8 * 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", __FUNCTION__);

	/* 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", __FUNCTION__, 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", __FUNCTION__, 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", __FUNCTION__);

	/* 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(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(tuple, tupleLength, "DVB_HOST", 8) == NULL) ||
			    (findstr(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", __FUNCTION__);

	/* 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;