WebSVN - shark - Blame - Rev 569 - /shark/trunk/drivers/cm7326/saa7146

Rev	Author	Line No.	Line
425	giacomo	1	#include <linux/version.h>
		2	#include <media/saa7146_vv.h>
		3
		4	/* helper function */
		5	static void my_wait(struct saa7146_dev *dev, long ms)
		6	{
		7	set_current_state(TASK_INTERRUPTIBLE);
		8	schedule_timeout((((ms+10)/10)*HZ)/1000);
		9	}
		10
		11	u32 saa7146_i2c_func(struct i2c_adapter *adapter)
		12	{
		13	//fm DEB_I2C(("'%s'.\n", adapter->name));
		14
		15	return I2C_FUNC_I2C
		16	\| I2C_FUNC_SMBUS_QUICK
		17	\| I2C_FUNC_SMBUS_READ_BYTE \| I2C_FUNC_SMBUS_WRITE_BYTE
		18	\| I2C_FUNC_SMBUS_READ_BYTE_DATA \| I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
		19	}
		20
		21	/* this function returns the status-register of our i2c-device */
		22	static inline u32 saa7146_i2c_status(struct saa7146_dev *dev)
		23	{
		24	u32 iicsta = saa7146_read(dev, I2C_STATUS);
		25	/*
		26	DEB_I2C(("status: 0x%08x\n",iicsta));
		27	*/
		28	return iicsta;
		29	}
		30
		31	/* this function runs through the i2c-messages and prepares the data to be
		32	sent through the saa7146. have a look at the specifications p. 122 ff
		33	to understand this. it returns the number of u32s to send, or -1
		34	in case of an error. */
		35	static int saa7146_i2c_msg_prepare(const struct i2c_msg m[], int num, u32 *op)
		36	{
		37	int h1, h2;
		38	int i, j, addr;
		39	int mem = 0, op_count = 0;
		40
		41	/* first determine size of needed memory */
		42	for(i = 0; i < num; i++) {
		43	mem += m[i].len + 1;
		44	}
		45
		46	/* worst case: we need one u32 for three bytes to be send
		47	plus one extra byte to address the device */
		48	mem = 1 + ((mem-1) / 3);
		49
		50	/* we assume that op points to a memory of at least SAA7146_I2C_MEM bytes
		51	size. if we exceed this limit... */
		52	if ( (4*mem) > SAA7146_I2C_MEM ) {
		53	//fm DEB_I2C(("cannot prepare i2c-message.\n"));
		54	return -ENOMEM;
		55	}
		56
		57	/* be careful: clear out the i2c-mem first */
		58	memset(op,0,sizeof(u32)*mem);
		59
		60	/* loop through all messages */
		61	for(i = 0; i < num; i++) {
		62
		63	/* insert the address of the i2c-slave.
		64	note: we get 7 bit i2c-addresses,
		65	so we have to perform a translation */
		66	addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0);
		67	h1 = op_count/3; h2 = op_count%3;
		68	op[h1] \|= ( (u8)addr << ((3-h2)*8));
		69	op[h1] \|= (SAA7146_I2C_START << ((3-h2)*2));
		70	op_count++;
		71
		72	/* loop through all bytes of message i */
		73	for(j = 0; j < m[i].len; j++) {
		74	/* insert the data bytes */
		75	h1 = op_count/3; h2 = op_count%3;
		76	op[h1] \|= ( (u32)((u8)m[i].buf[j]) << ((3-h2)*8));
		77	op[h1] \|= ( SAA7146_I2C_CONT << ((3-h2)*2));
		78	op_count++;
		79	}
		80
		81	}
		82
		83	/* have a look at the last byte inserted:
		84	if it was: ...CONT change it to ...STOP */
		85	h1 = (op_count-1)/3; h2 = (op_count-1)%3;
		86	if ( SAA7146_I2C_CONT == (0x3 & (op[h1] >> ((3-h2)*2))) ) {
		87	op[h1] &= ~(0x2 << ((3-h2)*2));
		88	op[h1] \|= (SAA7146_I2C_STOP << ((3-h2)*2));
		89	}
		90
		91	/* return the number of u32s to send */
		92	return mem;
		93	}
		94
		95	/* this functions loops through all i2c-messages. normally, it should determine
		96	which bytes were read through the adapter and write them back to the corresponding
		97	i2c-message. but instead, we simply write back all bytes.
		98	fixme: this could be improved. */
		99	static int saa7146_i2c_msg_cleanup(const struct i2c_msg m[], int num, u32 *op)
		100	{
		101	int i, j;
		102	int op_count = 0;
		103
		104	/* loop through all messages */
		105	for(i = 0; i < num; i++) {
		106
		107	op_count++;
		108
		109	/* loop throgh all bytes of message i */
		110	for(j = 0; j < m[i].len; j++) {
		111	/* write back all bytes that could have been read */
		112	m[i].buf[j] = (op[op_count/3] >> ((3-(op_count%3))*8));
		113	op_count++;
		114	}
		115	}
		116
		117	return 0;
		118	}
		119
		120	/* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */
		121	static int saa7146_i2c_reset(struct saa7146_dev *dev)
		122	{
		123	/* get current status */
		124	u32 status = saa7146_i2c_status(dev);
		125
		126	/* clear registers for sure */
		127	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		128	saa7146_write(dev, I2C_TRANSFER, 0);
		129
		130	/* check if any operation is still in progress */
		131	if ( 0 != ( status & SAA7146_I2C_BUSY) ) {
		132
		133	/* yes, kill ongoing operation */
		134	DEB_I2C(("busy_state detected.\n"));
		135
		136	/* set "ABORT-OPERATION"-bit (bit 7)*/
		137	saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate \| MASK_07));
		138	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		139	my_wait(dev,SAA7146_I2C_DELAY);
		140
		141	/* clear all error-bits pending; this is needed because p.123, note 1 */
		142	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		143	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		144	my_wait(dev,SAA7146_I2C_DELAY);
		145	}
		146
		147	/* check if any error is (still) present. (this can be necessary because p.123, note 1) */
		148	status = saa7146_i2c_status(dev);
		149
		150	if ( dev->i2c_bitrate != status ) {
		151
		152	DEB_I2C(("error_state detected. status:0x%08x\n",status));
		153
		154	/* Repeat the abort operation. This seems to be necessary
		155	after serious protocol errors caused by e.g. the SAA7740 */
		156	saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate \| MASK_07));
		157	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		158	my_wait(dev,SAA7146_I2C_DELAY);
		159
		160	/* clear all error-bits pending */
		161	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		162	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		163	my_wait(dev,SAA7146_I2C_DELAY);
		164
		165	/* the data sheet says it might be necessary to clear the status
		166	twice after an abort */
		167	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		168	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		169	my_wait(dev,SAA7146_I2C_DELAY);
		170	}
		171
		172	/* if any error is still present, a fatal error has occured ... */
		173	status = saa7146_i2c_status(dev);
		174	if ( dev->i2c_bitrate != status ) {
		175	DEB_I2C(("fatal error. status:0x%08x\n",status));
		176	return -1;
		177	}
		178
		179	return 0;
		180	}
		181
		182	/* this functions writes out the data-byte 'dword' to the i2c-device.
		183	it returns 0 if ok, -1 if the transfer failed, -2 if the transfer
		184	failed badly (e.g. address error) */
		185	static int saa7146_i2c_writeout(struct saa7146_dev dev, u32 dword, int short_delay)
		186	{
		187	u32 status = 0, mc2 = 0;
		188	int trial = 0;
		189	unsigned long timeout;
		190
		191	/* write out i2c-command */
		192	DEB_I2C(("before: 0x%08x (status: 0x%08x), %d\n",*dword,saa7146_read(dev, I2C_STATUS), dev->i2c_op));
		193
		194	if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
		195
		196	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		197	saa7146_write(dev, I2C_TRANSFER, *dword);
		198
		199	dev->i2c_op = 1;
		200	IER_ENABLE(dev, MASK_16\|MASK_17);
		201	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		202
		203	wait_event_interruptible(dev->i2c_wq, dev->i2c_op == 0);
		204	if (signal_pending (current)) {
		205	/* a signal arrived */
		206	return -ERESTARTSYS;
		207	}
		208	status = saa7146_read(dev, I2C_STATUS);
		209	} else {
		210	saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
		211	saa7146_write(dev, I2C_TRANSFER, *dword);
		212	saa7146_write(dev, MC2, (MASK_00 \| MASK_16));
		213
		214	/* do not poll for i2c-status before upload is complete */
		215	timeout = jiffies + HZ/100 + 1; /* 10ms */
		216	while(1) {
		217	mc2 = (saa7146_read(dev, MC2) & 0x1);
		218	if( 0 != mc2 ) {
		219	break;
		220	}
		221	if (time_after(jiffies,timeout)) {
		222	printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for MC2\n");
		223	return -EIO;
		224	}
		225	}
		226	/* wait until we get a transfer done or error */
		227	timeout = jiffies + HZ/100 + 1; /* 10ms */
		228	while(1) {
		229	/**
		230	* first read usually delivers bogus results...
		231	*/
		232	saa7146_i2c_status(dev);
		233	status = saa7146_i2c_status(dev);
		234	if ((status & 0x3) != 1)
		235	break;
		236	if (time_after(jiffies,timeout)) {
		237	/* this is normal when probing the bus
		238	* (no answer from nonexisistant device...)
		239	*/
		240	DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n"));
		241	return -EIO;
		242	}
		243	if ((++trial < 20) && short_delay)
		244	udelay(10);
		245	else
		246	my_wait(dev,1);
		247	}
		248	}
		249
		250	/* give a detailed status report */
		251	if ( 0 != (status & SAA7146_I2C_ERR)) {
		252
		253	if( 0 != (status & SAA7146_I2C_SPERR) ) {
		254	DEB_I2C(("error due to invalid start/stop condition.\n"));
		255	}
		256	if( 0 != (status & SAA7146_I2C_DTERR) ) {
		257	DEB_I2C(("error in data transmission.\n"));
		258	}
		259	if( 0 != (status & SAA7146_I2C_DRERR) ) {
		260	DEB_I2C(("error when receiving data.\n"));
		261	}
		262	if( 0 != (status & SAA7146_I2C_AL) ) {
		263	DEB_I2C(("error because arbitration lost.\n"));
		264	}
		265
		266	/* we handle address-errors here */
		267	if( 0 != (status & SAA7146_I2C_APERR) ) {
		268	DEB_I2C(("error in address phase.\n"));
		269	return -EREMOTEIO;
		270	}
		271
		272	return -EIO;
		273	}
		274
		275	/* read back data, just in case we were reading ... */
		276	*dword = saa7146_read(dev, I2C_TRANSFER);
		277
		278	DEB_I2C(("after: 0x%08x\n",*dword));
		279	return 0;
		280	}
		281
		282	int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg msgs[], int num, int retries)
		283	{
		284	int i = 0, count = 0;
		285	u32* buffer = dev->d_i2c.cpu_addr;
		286	int err = 0;
		287	int address_err = 0;
		288	int short_delay = 0;
		289
		290	if (down_interruptible (&dev->i2c_lock))
		291	return -ERESTARTSYS;
		292
		293	for(i=0;i<num;i++) {
		294	DEB_I2C(("msg:%d/%d\n",i+1,num));
		295	}
		296
		297	/* prepare the message(s), get number of u32s to transfer */
		298	count = saa7146_i2c_msg_prepare(msgs, num, buffer);
		299	if ( 0 > count ) {
		300	err = -1;
		301	goto out;
		302	}
		303
		304	if ( count > 3 \|\| 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) )
		305	short_delay = 1;
		306
		307	do {
		308	/* reset the i2c-device if necessary */
		309	err = saa7146_i2c_reset(dev);
		310	if ( 0 > err ) {
		311	DEB_I2C(("could not reset i2c-device.\n"));
		312	goto out;
		313	}
		314
		315	/* write out the u32s one after another */
		316	for(i = 0; i < count; i++) {
		317	err = saa7146_i2c_writeout(dev, &buffer[i], short_delay);
		318	if ( 0 != err) {
		319	/* this one is unsatisfying: some i2c slaves on some
		320	dvb cards don't acknowledge correctly, so the saa7146
		321	thinks that an address error occured. in that case, the
		322	transaction should be retrying, even if an address error
		323	occured. analog saa7146 based cards extensively rely on
		324	i2c address probing, however, and address errors indicate that a
		325	device is really not there. retrying in that case
		326	increases the time the device needs to probe greatly, so
		327	it should be avoided. because of the fact, that only
		328	analog based cards use irq based i2c transactions (for dvb
		329	cards, this screwes up other interrupt sources), we bail out
		330	completely for analog cards after an address error and trust
		331	the saa7146 address error detection. */
		332	if ( -EREMOTEIO == err ) {
		333	if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
		334	goto out;
		335	}
		336	address_err++;
		337	}
		338	DEB_I2C(("error while sending message(s). starting again.\n"));
		339	break;
		340	}
		341	}
		342	if( 0 == err ) {
		343	err = num;
		344	break;
		345	}
		346
		347	/* delay a bit before retrying */
		348	my_wait(dev, 10);
		349
		350	} while (err != num && retries--);
		351
		352	/* if every retry had an address error, exit right away */
		353	if (address_err == retries) {
		354	goto out;
		355	}
		356
		357	/* if any things had to be read, get the results */
		358	if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) {
		359	DEB_I2C(("could not cleanup i2c-message.\n"));
		360	err = -1;
		361	goto out;
		362	}
		363
		364	/* return the number of delivered messages */
		365	DEB_I2C(("transmission successful. (msg:%d).\n",err));
		366	out:
		367	/* another bug in revision 0: the i2c-registers get uploaded randomly by other
		368	uploads, so we better clear them out before continueing */
		369	if( 0 == dev->revision ) {
		370	u32 zero = 0;
		371	saa7146_i2c_reset(dev);
		372	if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) {
		373	INFO(("revision 0 error. this should never happen.\n"));
		374	}
		375	}
		376
		377	up(&dev->i2c_lock);
		378	return err;
		379	}
		380
		381	/* utility functions */
		382	static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg msg[], int num)
		383	{
		384	struct saa7146_dev* dev = i2c_get_adapdata(adapter);
		385
		386	/* use helper function to transfer data */
		387	return saa7146_i2c_transfer(dev, msg, num, adapter->retries);
		388	}
		389
		390
		391	/*****************************************************************************/
		392	/* i2c-adapter helper functions */
		393	#include <linux/i2c-id.h>
		394
		395	/* exported algorithm data */
		396	static struct i2c_algorithm saa7146_algo = {
		397	.name = "saa7146 i2c algorithm",
		398	.id = I2C_ALGO_SAA7146,
		399	.master_xfer = saa7146_i2c_xfer,
		400	.functionality = saa7146_i2c_func,
		401	};
		402
		403	int saa7146_i2c_adapter_prepare(struct saa7146_dev dev, struct i2c_adapter i2c_adapter, u32 bitrate)
		404	{
		405	DEB_EE(("bitrate: 0x%08x\n",bitrate));
		406
		407	/* enable i2c-port pins */
		408	saa7146_write(dev, MC1, (MASK_08 \| MASK_24));
		409
		410	dev->i2c_bitrate = bitrate;
		411	saa7146_i2c_reset(dev);
		412
		413	if( NULL != i2c_adapter ) {
		414	memset(i2c_adapter,0,sizeof(struct i2c_adapter));
		415	strcpy(i2c_adapter->name, dev->name);
		416	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
		417	i2c_adapter->data = dev;
		418	#else
		419	i2c_set_adapdata(i2c_adapter,dev);
		420	#endif
		421	i2c_adapter->algo = &saa7146_algo;
		422	i2c_adapter->algo_data = NULL;
		423	i2c_adapter->id = I2C_ALGO_SAA7146;
		424	i2c_adapter->timeout = SAA7146_I2C_TIMEOUT;
		425	i2c_adapter->retries = SAA7146_I2C_RETRIES;
		426	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
		427	#else
		428	i2c_adapter->class = I2C_ADAP_CLASS_TV_ANALOG;
		429	#endif
		430	}
		431
		432	return 0;
		433	}

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(root)/shark/trunk/drivers/cm7326/saa7146_i2c.c - Rev 569