pvrusb2-i2c-core.c

V4l driver for DVB HD

/*
 *
 *  $Id$
 *
 *  Copyright (C) 2005 Mike Isely <[e-mail]>
 *
 *  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
 *
 *  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
 *
 */

#include "compat.h"
#include "pvrusb2-i2c-core.h"
#include "pvrusb2-hdw-internal.h"
#include "pvrusb2-debug.h"

#define trace_i2c(...) pvr2_trace(PVR2_TRACE_I2C,__VA_ARGS__)

/*

  This module attempts to implement a compliant I2C adapter for the pvrusb2
  device.  By doing this we can then make use of existing functionality in
  V4L (e.g. tuner.c) rather than rolling our own.

*/

static unsigned int i2c_scan = 0;
module_param(i2c_scan, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");

static int pvr2_i2c_write(struct pvr2_hdw *hdw, /* Context */
			  u8 i2c_addr,      /* I2C address we're talking to */
			  u8 *data,         /* Data to write */
			  u16 length)       /* Size of data to write */
{
	/* Return value - default 0 means success */
	int ret;

#if 0
	trace_i2c("pvr2_i2c_write");
#endif

	if (!data) length = 0;
	if (length > (sizeof(hdw->cmd_buffer) - 3)) {
		pvr2_trace(PVR2_TRACE_ERROR_LEGS,
			   "Killing an I2C write to %u that is too large"
			   " (desired=%u limit=%u)",
			   i2c_addr,
			   length,(unsigned int)(sizeof(hdw->cmd_buffer) - 3));
		return -ENOTSUPP;
	}

	LOCK_TAKE(hdw->ctl_lock);

	/* Clear the command buffer (likely to be paranoia) */
	memset(hdw->cmd_buffer, 0, sizeof(hdw->cmd_buffer));

	/* Set up command buffer for an I2C write */
	hdw->cmd_buffer[0] = 0x08;      /* write prefix */
	hdw->cmd_buffer[1] = i2c_addr;  /* i2c addr of chip */
	hdw->cmd_buffer[2] = length;    /* length of what follows */
	if (length) memcpy(hdw->cmd_buffer + 3, data, length);

	/* Do the operation */
	ret = pvr2_send_request(hdw,
				hdw->cmd_buffer,
				length + 3,
				hdw->cmd_buffer,
				1);
	if (!ret) {
		if (hdw->cmd_buffer[0] != 8) {
			ret = -EIO;
			if (hdw->cmd_buffer[0] != 7) {
				trace_i2c("unexpected status"
					  " from i2_write[%d]: %d",
					  i2c_addr,hdw->cmd_buffer[0]);
			}
		}
	}
#if 0
	trace_i2c("i2c_write(0x%x) len=%d ret=%d stat=%d",i2c_addr,length,ret,
		  hdw->cmd_buffer[0]);
#endif

	LOCK_GIVE(hdw->ctl_lock);

	return ret;
}

static int pvr2_i2c_read(struct pvr2_hdw *hdw, /* Context */
			 u8 i2c_addr,       /* I2C address we're talking to */
			 u8 *data,          /* Data to write */
			 u16 dlen,          /* Size of data to write */
			 u8 *res,           /* Where to put data we read */
			 u16 rlen)          /* Amount of data to read */
{
	/* Return value - default 0 means success */
	int ret;

#if 0
	trace_i2c("pvr2_i2c_read");
#endif

	if (!data) dlen = 0;
	if (dlen > (sizeof(hdw->cmd_buffer) - 4)) return -ENOTSUPP;
	if (res && (rlen > (sizeof(hdw->cmd_buffer) - 1))) return -ENOTSUPP;

	LOCK_TAKE(hdw->ctl_lock);

	/* Clear the command buffer (likely to be paranoia) */
	memset(hdw->cmd_buffer, 0, sizeof(hdw->cmd_buffer));

	/* Set up command buffer for an I2C write followed by a read */
	hdw->cmd_buffer[0] = 0x09;  /* read prefix */
	hdw->cmd_buffer[1] = dlen;  /* arg length */
	hdw->cmd_buffer[2] = rlen;  /* answer length. Device will send one
				       more byte (status). */
	hdw->cmd_buffer[3] = i2c_addr;  /* i2c addr of chip */
	if (dlen) memcpy(hdw->cmd_buffer + 4, data, dlen);

	/* Do the operation */
	ret = pvr2_send_request(hdw,
				hdw->cmd_buffer,
				4 + dlen,
				hdw->cmd_buffer,
				rlen + 1);
	if (!ret) {
		if (hdw->cmd_buffer[0] != 8) {
			ret = -EIO;
			if (hdw->cmd_buffer[0] != 7) {
				trace_i2c("unexpected status"
					  " from i2_read[%d]: %d",
					  i2c_addr,hdw->cmd_buffer[0]);
			}
		}
	}

#if 0
	trace_i2c("i2c_read(0x%x) wlen=%d rlen=%d ret=%d stat=%d",
		  i2c_addr,dlen,rlen,ret,hdw->cmd_buffer[0]);
#endif
	/* Copy back the result */
	if (res && rlen) {
		if (ret) {
			/* Error, just blank out the return buffer */
			memset(res, 0, rlen);
		} else {
			memcpy(res, hdw->cmd_buffer + 1, rlen);
		}
	}

	LOCK_GIVE(hdw->ctl_lock);

	return ret;
}

/* This is a very, very limited I2C adapter implementation.  We can only
   support what we actually know will work on the device... */
static int pvr2_i2c_xfer(struct i2c_adapter *i2c_adap,
			 struct i2c_msg msgs[],
			 int num)
{
	int ret = -ENOTSUPP;
	struct pvr2_hdw *hdw = (struct pvr2_hdw *)(i2c_adap->algo_data);

	if ((msgs[0].flags & I2C_M_NOSTART)) {
		trace_i2c("i2c refusing I2C_M_NOSTART");
		goto done;
	}

	if (num == 1) {
		if (msgs[0].flags & I2C_M_RD) {
			/* Simple read */
			u16 tcnt,bcnt,offs;
			if (!msgs[0].len) {
				/* Length == 0 read.  This is a probe. */
				if (pvr2_i2c_read(hdw,msgs[0].addr,
						  0,0,0,0)) {
					ret = -EIO;
					goto done;
				}
				ret = 1;
				goto done;
			}
			/* If the read is short enough we'll do the whole
			   thing atomically.  Otherwise we have no choice
			   but to break apart the reads. */
			tcnt = msgs[0].len;
			offs = 0;
			while (tcnt) {
				bcnt = tcnt;
				if (bcnt > sizeof(hdw->cmd_buffer)-1) {
					bcnt = sizeof(hdw->cmd_buffer)-1;
				}
				if (pvr2_i2c_read(hdw,msgs[0].addr,
						  0,0,
						  msgs[0].buf+offs,bcnt)) {
					ret = -EIO;
					goto done;
				}
				offs += bcnt;
				tcnt -= bcnt;
			}
			ret = 1;
			goto done;
		} else {
			/* Simple write */
			ret = 1;
			if (pvr2_i2c_write(hdw,msgs[0].addr,
					   msgs[0].buf,msgs[0].len)) {
				ret = -EIO;
			}
			goto done;
		}
	} else if (num == 2) {
		if ((!((msgs[0].flags & I2C_M_RD))) &&
		    (msgs[1].flags & I2C_M_RD)) {
			u16 tcnt,bcnt,wcnt,offs;
			/* Write followed by atomic read.  If the read
			   portion is short enough we'll do the whole thing
			   atomically.  Otherwise we have no choice but to
			   break apart the reads. */
			tcnt = msgs[1].len;
			wcnt = msgs[0].len;
			offs = 0;
			while (tcnt || wcnt) {
				bcnt = tcnt;
				if (bcnt > sizeof(hdw->cmd_buffer)-1) {
					bcnt = sizeof(hdw->cmd_buffer)-1;
				}
				if (pvr2_i2c_read(hdw,msgs[0].addr,
						  msgs[0].buf,wcnt,
						  msgs[1].buf+offs,bcnt)) {
					ret = -EIO;
					goto done;
				}
				offs += bcnt;
				tcnt -= bcnt;
				wcnt = 0;
			}
			ret = 2;
			goto done;
		} else {
			trace_i2c("i2c refusing complex transfer"
				  " read0=%d read1=%d",
				  (msgs[0].flags & I2C_M_RD),
				  (msgs[1].flags & I2C_M_RD));
		}
	} else {
		trace_i2c("i2c refusing %d phase transfer",num);
	}

 done:
	if (pvrusb2_debug & PVR2_TRACE_I2C_TRAF) {
		unsigned int idx,offs,cnt;
		for (idx = 0; idx < num; idx++) {
			cnt = msgs[idx].len;
			printk(KERN_INFO
			       "pvrusb2 i2c xfer %u/%u:"
			       " addr=0x%x len=%d %s%s",
			       idx+1,num,
			       msgs[idx].addr,
			       cnt,
			       (msgs[idx].flags & I2C_M_RD ?
				"read" : "write"),
			       (msgs[idx].flags & I2C_M_NOSTART ?
				" nostart" : ""));
			if ((ret > 0) || !(msgs[idx].flags & I2C_M_RD)) {
				if (cnt > 8) cnt = 8;
				printk(" [");
				for (offs = 0; offs < (cnt>8?8:cnt); offs++) {
					if (offs) printk(" ");
					printk("%02x",msgs[idx].buf[offs]);
				}
				if (offs < cnt) printk(" ...");
				printk("]");
			}
			if (idx+1 == num) {
				printk(" result=%d",ret);
			}
			printk("\n");
		}
		if (!num) {
			printk(KERN_INFO
			       "pvrusb2 i2c xfer null transfer result=%d\n",
			       ret);
		}
	}
	return ret;
}

static int pvr2_i2c_control(struct i2c_adapter *adapter,
			    unsigned int cmd, unsigned long arg)
{
	return 0;
}

static u32 pvr2_i2c_functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA;
}

static int pvr2_i2c_core_singleton(struct i2c_client *cp,
				   unsigned int cmd,void *arg)
{
	int stat;
	if (!cp) return -EINVAL;
	if (!(cp->driver)) return -EINVAL;
	if (!(cp->driver->command)) return -EINVAL;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16)
	if (!try_module_get(cp->driver->owner)) return -EAGAIN;
#else
	if (!try_module_get(cp->driver->driver.owner)) return -EAGAIN;
#endif
	stat = cp->driver->command(cp,cmd,arg);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,16)
	module_put(cp->driver->owner);
#else
	module_put(cp->driver->driver.owner);
#endif
	return stat;
}

int pvr2_i2c_client_cmd(struct pvr2_i2c_client *cp,unsigned int cmd,void *arg)
{
	int stat;
	if (pvrusb2_debug & PVR2_TRACE_I2C_CMD) {
		char buf[100];
		unsigned int cnt;
		cnt = pvr2_i2c_client_describe(cp,PVR2_I2C_DETAIL_DEBUG,
					       buf,sizeof(buf));
		pvr2_trace(PVR2_TRACE_I2C_CMD,
			   "i2c COMMAND (code=%u 0x%x) to %.*s",
			   cmd,cmd,cnt,buf);
	}
	stat = pvr2_i2c_core_singleton(cp->client,cmd,arg);
	if (pvrusb2_debug & PVR2_TRACE_I2C_CMD) {
		char buf[100];
		unsigned int cnt;
		cnt = pvr2_i2c_client_describe(cp,PVR2_I2C_DETAIL_DEBUG,
					       buf,sizeof(buf));
		pvr2_trace(PVR2_TRACE_I2C_CMD,
			   "i2c COMMAND to %.*s (ret=%d)",cnt,buf,stat);
	}
	return stat;
}

int pvr2_i2c_core_cmd(struct pvr2_hdw *hdw,unsigned int cmd,void *arg)
{
	struct list_head *item,*nc;
	struct pvr2_i2c_client *cp;
	int stat = -EINVAL;

	if (!hdw) return stat;

	mutex_lock(&hdw->i2c_list_lock);
	list_for_each_safe(item,nc,&hdw->i2c_clients) {
		cp = list_entry(item,struct pvr2_i2c_client,list);
		if (!cp->recv_enable) continue;
		mutex_unlock(&hdw->i2c_list_lock);
		stat = pvr2_i2c_client_cmd(cp,cmd,arg);
		mutex_lock(&hdw->i2c_list_lock);
	}
	mutex_unlock(&hdw->i2c_list_lock);
	return stat;
}


static int handler_check(struct pvr2_i2c_client *cp)
{
	struct pvr2_i2c_handler *hp = cp->handler;
	if (!hp) return 0;
	if (!hp->func_table->check) return 0;
	return hp->func_table->check(hp->func_data) != 0;
}

#define BUFSIZE 500

void pvr2_i2c_core_sync(struct pvr2_hdw *hdw)
{
	unsigned long msk;
	unsigned int idx;
	struct list_head *item,*nc;
	struct pvr2_i2c_client *cp;

	if (!hdw->i2c_linked) return;
	if (!(hdw->i2c_pend_types & PVR2_I2C_PEND_ALL)) {
		return;