Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 573 insertions, 0 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
new file mode 100644
index 000000000000..fb5b732238ed
--- /dev/null
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -0,0 +1,573 @@
+/* ------------------------------------------------------------------------- */
+/* i2c-algo-bit.c i2c driver algorithms for bit-shift adapters		     */
+/* ------------------------------------------------------------------------- */
+/*   Copyright (C) 1995-2000 Simon G. Vogl
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
+/* ------------------------------------------------------------------------- */
+
+/* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki
+   <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
+
+/* ----- global defines ----------------------------------------------- */
+#define DEB(x) if (i2c_debug>=1) x;
+#define DEB2(x) if (i2c_debug>=2) x;
+#define DEBSTAT(x) if (i2c_debug>=3) x; /* print several statistical values*/
+#define DEBPROTO(x) if (i2c_debug>=9) { x; }
+ 	/* debug the protocol by showing transferred bits */
+
+
+/* ----- global variables ---------------------------------------------	*/
+
+/* module parameters:
+ */
+static int i2c_debug;
+static int bit_test;	/* see if the line-setting functions work	*/
+
+/* --- setting states on the bus with the right timing: ---------------	*/
+
+#define setsda(adap,val) adap->setsda(adap->data, val)
+#define setscl(adap,val) adap->setscl(adap->data, val)
+#define getsda(adap) adap->getsda(adap->data)
+#define getscl(adap) adap->getscl(adap->data)
+
+static inline void sdalo(struct i2c_algo_bit_data *adap)
+{
+	setsda(adap,0);
+	udelay(adap->udelay);
+}
+
+static inline void sdahi(struct i2c_algo_bit_data *adap)
+{
+	setsda(adap,1);
+	udelay(adap->udelay);
+}
+
+static inline void scllo(struct i2c_algo_bit_data *adap)
+{
+	setscl(adap,0);
+	udelay(adap->udelay);
+}
+
+/*
+ * Raise scl line, and do checking for delays. This is necessary for slower
+ * devices.
+ */
+static inline int sclhi(struct i2c_algo_bit_data *adap)
+{
+	unsigned long start;
+
+	setscl(adap,1);
+
+	/* Not all adapters have scl sense line... */
+	if (adap->getscl == NULL ) {
+		udelay(adap->udelay);
+		return 0;
+	}
+
+	start=jiffies;
+	while (! getscl(adap) ) {	
+ 		/* the hw knows how to read the clock line,
+ 		 * so we wait until it actually gets high.
+ 		 * This is safer as some chips may hold it low
+ 		 * while they are processing data internally. 
+ 		 */
+		if (time_after_eq(jiffies, start+adap->timeout)) {
+			return -ETIMEDOUT;
+		}
+		cond_resched();
+	}
+	DEBSTAT(printk(KERN_DEBUG "needed %ld jiffies\n", jiffies-start));
+	udelay(adap->udelay);
+	return 0;
+} 
+
+
+/* --- other auxiliary functions --------------------------------------	*/
+static void i2c_start(struct i2c_algo_bit_data *adap) 
+{
+	/* assert: scl, sda are high */
+	DEBPROTO(printk("S "));
+	sdalo(adap);
+	scllo(adap);
+}
+
+static void i2c_repstart(struct i2c_algo_bit_data *adap) 
+{
+	/* scl, sda may not be high */
+	DEBPROTO(printk(" Sr "));
+	setsda(adap,1);
+	sclhi(adap);
+	udelay(adap->udelay);
+	
+	sdalo(adap);
+	scllo(adap);
+}
+
+
+static void i2c_stop(struct i2c_algo_bit_data *adap) 
+{
+	DEBPROTO(printk("P\n"));
+	/* assert: scl is low */
+	sdalo(adap);
+	sclhi(adap); 
+	sdahi(adap);
+}
+
+
+
+/* send a byte without start cond., look for arbitration, 
+   check ackn. from slave */
+/* returns:
+ * 1 if the device acknowledged
+ * 0 if the device did not ack
+ * -ETIMEDOUT if an error occurred (while raising the scl line)
+ */
+static int i2c_outb(struct i2c_adapter *i2c_adap, char c)
+{
+	int i;
+	int sb;
+	int ack;
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+
+	/* assert: scl is low */
+	for ( i=7 ; i>=0 ; i-- ) {
+		sb = c & ( 1 << i );
+		setsda(adap,sb);
+		udelay(adap->udelay);
+		DEBPROTO(printk(KERN_DEBUG "%d",sb!=0));
+		if (sclhi(adap)<0) { /* timed out */
+			sdahi(adap); /* we don't want to block the net */
+			DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x, timeout at bit #%d\n", c&0xff, i));
+			return -ETIMEDOUT;
+		};
+		/* do arbitration here: 
+		 * if ( sb && ! getsda(adap) ) -> ouch! Get out of here.
+		 */
+		setscl(adap, 0 );
+		udelay(adap->udelay);
+	}
+	sdahi(adap);
+	if (sclhi(adap)<0){ /* timeout */
+	    DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x, timeout at ack\n", c&0xff));
+	    return -ETIMEDOUT;
+	};
+	/* read ack: SDA should be pulled down by slave */
+	ack=getsda(adap);	/* ack: sda is pulled low ->success.	 */
+	DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x , getsda() = %d\n", c & 0xff, ack));
+
+	DEBPROTO( printk(KERN_DEBUG "[%2.2x]",c&0xff) );
+	DEBPROTO(if (0==ack){ printk(KERN_DEBUG " A ");} else printk(KERN_DEBUG " NA ") );
+	scllo(adap);
+	return 0==ack;		/* return 1 if device acked	 */
+	/* assert: scl is low (sda undef) */
+}
+
+
+static int i2c_inb(struct i2c_adapter *i2c_adap) 
+{
+	/* read byte via i2c port, without start/stop sequence	*/
+	/* acknowledge is sent in i2c_read.			*/
+	int i;
+	unsigned char indata=0;
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+
+	/* assert: scl is low */
+	sdahi(adap);
+	for (i=0;i<8;i++) {
+		if (sclhi(adap)<0) { /* timeout */
+			DEB2(printk(KERN_DEBUG " i2c_inb: timeout at bit #%d\n", 7-i));
+			return -ETIMEDOUT;
+		};
+		indata *= 2;
+		if ( getsda(adap) ) 
+			indata |= 0x01;
+		scllo(adap);
+	}
+	/* assert: scl is low */
+	DEB2(printk(KERN_DEBUG "i2c_inb: 0x%02x\n", indata & 0xff));
+
+	DEBPROTO(printk(KERN_DEBUG " 0x%02x", indata & 0xff));
+	return (int) (indata & 0xff);
+}
+
+/*
+ * Sanity check for the adapter hardware - check the reaction of
+ * the bus lines only if it seems to be idle.
+ */
+static int test_bus(struct i2c_algo_bit_data *adap, char* name) {
+	int scl,sda;
+
+	if (adap->getscl==NULL)
+		printk(KERN_INFO "i2c-algo-bit.o: Testing SDA only, "
+			"SCL is not readable.\n");
+
+	sda=getsda(adap);
+	scl=(adap->getscl==NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (0) scl=%d, sda=%d\n",scl,sda);
+	if (!scl || !sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: %s seems to be busy.\n", name);
+		goto bailout;
+	}
+
+	sdalo(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl==NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (1) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 != sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck high!\n");
+		goto bailout;
+	}
+	if ( 0 == scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low "
+			"while pulling SDA low!\n");
+		goto bailout;
+	}		
+
+	sdahi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl==NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (2) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 == sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck low!\n");
+		goto bailout;
+	}
+	if ( 0 == scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low "
+			"while pulling SDA high!\n");
+		goto bailout;
+	}
+
+	scllo(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl==NULL?0:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (3) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 != scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck high!\n");
+		goto bailout;
+	}
+	if ( 0 == sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low "
+			"while pulling SCL low!\n");
+		goto bailout;
+	}
+	
+	sclhi(adap);
+	sda=getsda(adap);
+	scl=(adap->getscl==NULL?1:getscl(adap));
+	printk(KERN_DEBUG "i2c-algo-bit.o: (4) scl=%d, sda=%d\n",scl,sda);
+	if ( 0 == scl ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck low!\n");
+		goto bailout;
+	}
+	if ( 0 == sda ) {
+		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low "
+			"while pulling SCL high!\n");
+		goto bailout;
+	}
+	printk(KERN_INFO "i2c-algo-bit.o: %s passed test.\n",name);
+	return 0;
+bailout:
+	sdahi(adap);
+	sclhi(adap);
+	return -ENODEV;
+}
+
+/* ----- Utility functions
+ */
+
+/* try_address tries to contact a chip for a number of
+ * times before it gives up.
+ * return values:
+ * 1 chip answered
+ * 0 chip did not answer
+ * -x transmission error
+ */
+static inline int try_address(struct i2c_adapter *i2c_adap,
+		       unsigned char addr, int retries)
+{
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+	int i,ret = -1;
+	for (i=0;i<=retries;i++) {
+		ret = i2c_outb(i2c_adap,addr);
+		if (ret==1)
+			break;	/* success! */
+		i2c_stop(adap);
+		udelay(5/*adap->udelay*/);
+		if (i==retries)  /* no success */
+			break;
+		i2c_start(adap);
+		udelay(adap->udelay);
+	}
+	DEB2(if (i)
+	     printk(KERN_DEBUG "i2c-algo-bit.o: Used %d tries to %s client at 0x%02x : %s\n",
+		    i+1, addr & 1 ? "read" : "write", addr>>1,
+		    ret==1 ? "success" : ret==0 ? "no ack" : "failed, timeout?" )
+	    );
+	return ret;
+}
+
+static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
+{
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+	char c;
+	const char *temp = msg->buf;
+	int count = msg->len;
+	unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; 
+	int retval;
+	int wrcount=0;
+
+	while (count > 0) {
+		c = *temp;
+		DEB2(dev_dbg(&i2c_adap->dev, "sendbytes: writing %2.2X\n", c&0xff));
+		retval = i2c_outb(i2c_adap,c);
+		if ((retval>0) || (nak_ok && (retval==0)))  { /* ok or ignored NAK */
+			count--; 
+			temp++;
+			wrcount++;
+		} else { /* arbitration or no acknowledge */
+			dev_err(&i2c_adap->dev, "sendbytes: error - bailout.\n");
+			i2c_stop(adap);
+			return (retval<0)? retval : -EFAULT;
+			        /* got a better one ?? */
+		}
+#if 0
+		/* from asm/delay.h */
+		__delay(adap->mdelay * (loops_per_sec / 1000) );
+#endif
+	}
+	return wrcount;
+}
+
+static inline int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
+{
+	int inval;
+	int rdcount=0;   	/* counts bytes read */
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+	char *temp = msg->buf;
+	int count = msg->len;
+
+	while (count > 0) {
+		inval = i2c_inb(i2c_adap);
+/*printk("%#02x ",inval); if ( ! (count % 16) ) printk("\n"); */
+		if (inval>=0) {
+			*temp = inval;
+			rdcount++;
+		} else {   /* read timed out */
+			printk(KERN_ERR "i2c-algo-bit.o: readbytes: i2c_inb timed out.\n");
+			break;
+		}
+
+		temp++;
+		count--;
+
+		if (msg->flags & I2C_M_NO_RD_ACK)
+			continue;
+
+		if ( count > 0 ) {		/* send ack */
+			sdalo(adap);
+			DEBPROTO(printk(" Am "));
+		} else {
+			sdahi(adap);	/* neg. ack on last byte */
+			DEBPROTO(printk(" NAm "));
+		}
+		if (sclhi(adap)<0) {	/* timeout */
+			sdahi(adap);
+			printk(KERN_ERR "i2c-algo-bit.o: readbytes: Timeout at ack\n");
+			return -ETIMEDOUT;
+		};
+		scllo(adap);
+		sdahi(adap);
+	}
+	return rdcount;
+}
+
+/* doAddress initiates the transfer by generating the start condition (in
+ * try_address) and transmits the address in the necessary format to handle
+ * reads, writes as well as 10bit-addresses.
+ * returns:
+ *  0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set
+ * -x an error occurred (like: -EREMOTEIO if the device did not answer, or
+ *	-ETIMEDOUT, for example if the lines are stuck...) 
+ */
+static inline int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) 
+{
+	unsigned short flags = msg->flags;
+	unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK;
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+
+	unsigned char addr;
+	int ret, retries;
+
+	retries = nak_ok ? 0 : i2c_adap->retries;
+	
+	if ( (flags & I2C_M_TEN)  ) { 
+		/* a ten bit address */
+		addr = 0xf0 | (( msg->addr >> 7) & 0x03);
+		DEB2(printk(KERN_DEBUG "addr0: %d\n",addr));
+		/* try extended address code...*/
+		ret = try_address(i2c_adap, addr, retries);
+		if ((ret != 1) && !nak_ok)  {
+			printk(KERN_ERR "died at extended address code.\n");
+			return -EREMOTEIO;
+		}
+		/* the remaining 8 bit address */
+		ret = i2c_outb(i2c_adap,msg->addr & 0x7f);
+		if ((ret != 1) && !nak_ok) {
+			/* the chip did not ack / xmission error occurred */
+			printk(KERN_ERR "died at 2nd address code.\n");
+			return -EREMOTEIO;
+		}
+		if ( flags & I2C_M_RD ) {
+			i2c_repstart(adap);
+			/* okay, now switch into reading mode */
+			addr |= 0x01;
+			ret = try_address(i2c_adap, addr, retries);
+			if ((ret!=1) && !nak_ok) {
+				printk(KERN_ERR "died at extended address code.\n");
+				return -EREMOTEIO;
+			}
+		}
+	} else {		/* normal 7bit address	*/
+		addr = ( msg->addr << 1 );
+		if (flags & I2C_M_RD )
+			addr |= 1;
+		if (flags & I2C_M_REV_DIR_ADDR )
+			addr ^= 1;
+		ret = try_address(i2c_adap, addr, retries);
+		if ((ret!=1) && !nak_ok)
+			return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+static int bit_xfer(struct i2c_adapter *i2c_adap,
+		    struct i2c_msg msgs[], int num)
+{
+	struct i2c_msg *pmsg;
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+	
+	int i,ret;
+	unsigned short nak_ok;
+
+	i2c_start(adap);
+	for (i=0;i<num;i++) {
+		pmsg = &msgs[i];
+		nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; 
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			if (i) {
+				i2c_repstart(adap);
+			}
+			ret = bit_doAddress(i2c_adap, pmsg);
+			if ((ret != 0) && !nak_ok) {
+			    DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: NAK from device addr %2.2x msg #%d\n"
+					,msgs[i].addr,i));
+			    return (ret<0) ? ret : -EREMOTEIO;
+			}
+		}
+		if (pmsg->flags & I2C_M_RD ) {
+			/* read bytes into buffer*/
+			ret = readbytes(i2c_adap, pmsg);
+			DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: read %d bytes.\n",ret));
+			if (ret < pmsg->len ) {
+				return (ret<0)? ret : -EREMOTEIO;
+			}
+		} else {
+			/* write bytes from buffer */
+			ret = sendbytes(i2c_adap, pmsg);
+			DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: wrote %d bytes.\n",ret));
+			if (ret < pmsg->len ) {
+				return (ret<0) ? ret : -EREMOTEIO;
+			}
+		}
+	}
+	i2c_stop(adap);
+	return num;
+}
+
+static u32 bit_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 
+	       I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+
+/* -----exported algorithm data: -------------------------------------	*/
+
+static struct i2c_algorithm i2c_bit_algo = {
+	.name		= "Bit-shift algorithm",
+	.id		= I2C_ALGO_BIT,
+	.master_xfer	= bit_xfer,
+	.functionality	= bit_func,
+};
+
+/* 
+ * registering functions to load algorithms at runtime 
+ */
+int i2c_bit_add_bus(struct i2c_adapter *adap)
+{
+	struct i2c_algo_bit_data *bit_adap = adap->algo_data;
+
+	if (bit_test) {
+		int ret = test_bus(bit_adap, adap->name);
+		if (ret<0)
+			return -ENODEV;
+	}
+
+	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
+
+	/* register new adapter to i2c module... */
+
+	adap->id |= i2c_bit_algo.id;
+	adap->algo = &i2c_bit_algo;
+
+	adap->timeout = 100;	/* default values, should	*/
+	adap->retries = 3;	/* be replaced by defines	*/
+
+	i2c_add_adapter(adap);
+	return 0;
+}
+
+
+int i2c_bit_del_bus(struct i2c_adapter *adap)
+{
+	return i2c_del_adapter(adap);
+}
+
+EXPORT_SYMBOL(i2c_bit_add_bus);
+EXPORT_SYMBOL(i2c_bit_del_bus);
+
+MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C-Bus bit-banging algorithm");
+MODULE_LICENSE("GPL");
+
+module_param(bit_test, bool, 0);
+module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
+
+MODULE_PARM_DESC(bit_test, "Test the lines of the bus to see if it is stuck");
+MODULE_PARM_DESC(i2c_debug,
+		 "debug level - 0 off; 1 normal; 2,3 more verbose; 9 bit-protocol");