patch-2.3.34 linux/drivers/i2c/i2c-algo-pcf.c

• Lines: 608
• Date: Thu Dec 16 13:59:38 1999
• Orig file: v2.3.33/linux/drivers/i2c/i2c-algo-pcf.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.33/linux/drivers/i2c/i2c-algo-pcf.c linux/drivers/i2c/i2c-algo-pcf.c
@@ -0,0 +1,607 @@
+
+/* ------------------------------------------------------------------------- */
+/* i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters		     */
+/* ------------------------------------------------------------------------- */
+/*   Copyright (C) 1995-97 Simon G. Vogl
+                   1998-99 Hans Berglund
+
+    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 Kyösti Mälkki <kmalkki@cc.hut.fi> and even
+   Frodo Looijaard <frodol@dds.nl> */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/malloc.h>
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= 0x020135
+#include <linux/init.h>
+#else
+#define __init 
+#endif
+
+#if LINUX_VERSION_CODE >= 0x020100
+#  include <asm/uaccess.h>
+#else
+#  include <asm/segment.h>
+#endif
+
+
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+
+/* 2.0.0 kernel compatibility */
+#if LINUX_VERSION_CODE < 0x020100
+#define MODULE_AUTHOR(noone)
+#define MODULE_DESCRIPTION(none)
+#define MODULE_PARM(no,param)
+#define MODULE_PARM_DESC(no,description)
+#define EXPORT_SYMBOL(noexport)
+#define EXPORT_NO_SYMBOLS
+#endif
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-pcf.h>
+#include "i2c-pcf8584.h"
+
+/* ----- global defines ----------------------------------------------- */
+#define DEB(x) if (i2c_debug>=1) x
+#define DEB2(x) if (i2c_debug>=2) x
+#define DEB3(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 */
+#define DEF_TIMEOUT 16
+
+/* debugging - slow down transfer to have a look at the data .. 	*/
+/* I use this with two leds&resistors, each one connected to sda,scl 	*/
+/* respectively. This makes sure that the algorithm works. Some chips   */
+/* might not like this, as they have an internal timeout of some mils	*/
+/*
+#if LINUX_VERSION_CODE >= 0x02016e
+#define SLO_IO      jif=jiffies;while(jiffies<=jif+i2c_table[minor].veryslow)\
+                        if (need_resched) schedule();
+#else
+#define SLO_IO      jif=jiffies;while(jiffies<=jif+i2c_table[minor].veryslow)\
+			if (need_resched) schedule();
+#endif
+*/
+
+
+/* ----- global variables ---------------------------------------------	*/
+
+#ifdef SLO_IO
+	int jif;
+#endif
+
+/* module parameters:
+ */
+static int i2c_debug=1;
+static int pcf_test=0;	/* see if the line-setting functions work	*/
+static int pcf_scan=0;	/* have a look at what's hanging 'round		*/
+
+/* --- setting states on the bus with the right timing: ---------------	*/
+
+#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
+#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
+#define get_own(adap) adap->getown(adap->data)
+#define get_clock(adap) adap->getclock(adap->data)
+#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
+#define i2c_inb(adap) adap->getpcf(adap->data, 0)
+
+
+/* --- other auxiliary functions --------------------------------------	*/
+
+#if LINUX_VERSION_CODE < 0x02017f
+static void schedule_timeout(int j)
+{
+	current->state   = TASK_INTERRUPTIBLE;
+	current->timeout = jiffies + j;
+	schedule();
+}
+#endif
+
+
+static void i2c_start(struct i2c_algo_pcf_data *adap) 
+{
+   DEBPROTO(printk("S "));
+   set_pcf(adap, 1, I2C_PCF_START);
+}
+
+static void i2c_repstart(struct i2c_algo_pcf_data *adap) 
+{
+   DEBPROTO(printk(" Sr "));
+   set_pcf(adap, 1, I2C_PCF_REPSTART);
+}
+
+
+static void i2c_stop(struct i2c_algo_pcf_data *adap) 
+{
+   DEBPROTO(printk("P\n"));
+   set_pcf(adap, 1, I2C_PCF_STOP);
+}
+
+
+static int wait_for_bb(struct i2c_algo_pcf_data *adap) {
+
+   int timeout = DEF_TIMEOUT;
+   int status;
+
+   status = get_pcf(adap, 1);
+   while (timeout-- && !(status & I2C_PCF_BB)) {
+      udelay(1000); /* How much is this? */
+      status = get_pcf(adap, 1);
+   }
+   if (timeout<=0)
+      printk("Timeout waiting for Bus Busy\n");
+     /*
+      set_pcf(adap, 1, I2C_PCF_STOP);
+   */
+   return(timeout<=0);
+}
+
+
+static inline void pcf_sleep(unsigned long timeout)
+{
+	schedule_timeout( timeout * HZ);
+}
+
+
+static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {
+
+   int timeout = DEF_TIMEOUT;
+
+   *status = get_pcf(adap, 1);
+   while (timeout-- && (*status & I2C_PCF_PIN)) {
+      adap->waitforpin();
+      *status = get_pcf(adap, 1);
+   }
+   if (timeout <= 0)
+      return(-1);
+   else
+      return(0);
+}
+
+
+/* 
+ * This should perform the 'PCF8584 initialization sequence' as described
+ * in the Philips IC12 data book (1995, Aug 29).
+ * There should be a 30 clock cycle wait after reset, I assume this
+ * has been fulfilled.
+ * There should be a delay at the end equal to the longest I2C message
+ * to synchronize the BB-bit (in multimaster systems). How long is
+ * this? I assume 1 second is always long enough.
+ */
+static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
+{
+
+	/* S1=0x80: S0 selected, serial interface off			*/
+	set_pcf(adap, 1, I2C_PCF_PIN);
+
+	/* load own address in S0, effective address is (own << 1)	*/
+	i2c_outb(adap, get_own(adap));
+
+	/* S1=0xA0, next byte in S2					*/
+	set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
+
+	/* load clock register S2					*/
+	i2c_outb(adap, get_clock(adap));
+
+	/* Enable serial interface, idle, S0 selected			*/
+	set_pcf(adap, 1, I2C_PCF_IDLE);
+
+	DEB2(printk("i2c-algo-pcf.o: irq: Initialized 8584.\n"));
+	return 0;
+}
+
+
+/*
+ * 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_pcf_data *adap, char *name) {
+#if 0
+	int scl,sda;
+	sda=getsda(adap);
+	if (adap->getscl==NULL) {
+		printk("i2c-algo-pcf.o: Warning: Adapter can't read from clock line - skipping test.\n");
+		return 0;		
+	}
+	scl=getscl(adap);
+	printk("i2c-algo-pcf.o: Adapter: %s scl: %d  sda: %d -- testing...\n",
+	name,getscl(adap),getsda(adap));
+	if (!scl || !sda ) {
+		printk("i2c-algo-pcf.o: %s seems to be busy.\n",adap->name);
+		goto bailout;
+	}
+	sdalo(adap);
+	printk("i2c-algo-pcf.o:1 scl: %d  sda: %d \n",getscl(adap),getsda(adap));
+	if ( 0 != getsda(adap) ) {
+		printk("i2c-algo-pcf.o: %s SDA stuck high!\n",name);
+		sdahi(adap);
+		goto bailout;
+	}
+	if ( 0 == getscl(adap) ) {
+		printk("i2c-algo-pcf.o: %s SCL unexpected low while pulling SDA low!\n",
+			name);
+		goto bailout;
+	}		
+	sdahi(adap);
+	printk("i2c-algo-pcf.o:2 scl: %d  sda: %d \n",getscl(adap),getsda(adap));
+	if ( 0 == getsda(adap) ) {
+		printk("i2c-algo-pcf.o: %s SDA stuck low!\n",name);
+		sdahi(adap);
+		goto bailout;
+	}
+	if ( 0 == getscl(adap) ) {
+		printk("i2c-algo-pcf.o: %s SCL unexpected low while SDA high!\n",adap->name);
+	goto bailout;
+	}
+	scllo(adap);
+	printk("i2c-algo-pcf.o:3 scl: %d  sda: %d \n",getscl(adap),getsda(adap));
+	if ( 0 != getscl(adap) ) {
+		printk("i2c-algo-pcf.o: %s SCL stuck high!\n",name);
+		sclhi(adap);
+		goto bailout;
+	}
+	if ( 0 == getsda(adap) ) {
+		printk("i2c-algo-pcf.o: %s SDA unexpected low while pulling SCL low!\n",
+			name);
+		goto bailout;
+	}
+	sclhi(adap);
+	printk("i2c-algo-pcf.o:4 scl: %d  sda: %d \n",getscl(adap),getsda(adap));
+	if ( 0 == getscl(adap) ) {
+		printk("i2c-algo-pcf.o: %s SCL stuck low!\n",name);
+		sclhi(adap);
+		goto bailout;
+	}
+	if ( 0 == getsda(adap) ) {
+		printk("i2c-algo-pcf.o: %s SDA unexpected low while SCL high!\n",
+			name);
+		goto bailout;
+	}
+	printk("i2c-algo-pcf.o: %s passed test.\n",name);
+	return 0;
+bailout:
+	sdahi(adap);
+	sclhi(adap);
+	return -ENODEV;
+#endif
+	return (0);
+}
+
+/* ----- Utility functions
+ */
+
+static inline int try_address(struct i2c_algo_pcf_data *adap,
+		       unsigned char addr, int retries)
+{
+   int i, status, ret = -1;
+   for (i=0;i<retries;i++) {
+      i2c_outb(adap, addr);
+      i2c_start(adap);
+      status = get_pcf(adap, 1);
+      if (wait_for_pin(adap, &status) >= 0) {
+	 if ((status && I2C_PCF_LRB) == 0) { 
+	    i2c_stop(adap);
+	    break;	/* success! */
+	 }
+      }
+      i2c_stop(adap);
+      udelay(adap->udelay);
+   }
+   DEB2(if (i) printk("i2c-algo-pcf.o: needed %d retries for %d\n",i,addr));
+   return ret;
+}
+
+
+static int pcf_sendbytes(struct i2c_adapter *i2c_adap,const char *buf, int count)
+{
+   struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+   int wrcount, status, timeout;
+
+   for (wrcount=0; wrcount<count; ++wrcount) {
+      DEB2(printk("i2c-algo-pcf.o: %s i2c_write: writing %2.2X\n",
+		  i2c_adap->name, buf[wrcount]&0xff));
+      i2c_outb(adap, buf[wrcount]);
+      timeout = wait_for_pin(adap, &status);
+      if (timeout) {
+	 printk("i2c-algo-pcf.o: %s i2c_write: error - timeout.\n",
+		i2c_adap->name);
+	 i2c_stop(adap);
+	 return -EREMOTEIO; /* got a better one ?? */
+      }
+      if (status & I2C_PCF_LRB) {
+	 printk("i2c-algo-pcf.o: %s i2c_write: error - no ack.\n",
+		i2c_adap->name);
+	 i2c_stop(adap);
+	 return -EREMOTEIO; /* got a better one ?? */
+      }
+   }
+   return (wrcount);
+}
+
+
+static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
+{
+   int rdcount=0, i, status, timeout, dummy=1;
+   struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+ 
+   for (i=0; i<count-1; ++i) {
+      buf[rdcount] =  i2c_inb(adap);
+      if (dummy) {
+	 dummy = 0;
+      }
+      else
+	 rdcount++;
+      timeout = wait_for_pin(adap, &status);
+      if (timeout) {
+	 printk("i2c-algo-pcf.o: i2c_read: i2c_inb timed out.\n");
+	 return (-1);
+      }
+      if (status & I2C_PCF_LRB) {
+	 printk("i2c-algo-pcf.o: i2c_read: i2c_inb, No ack.\n");
+	 return (-1);
+      }
+   }
+   set_pcf(adap, 1, I2C_PCF_ESO);
+   buf[rdcount] = i2c_inb(adap);
+   if (dummy) {
+      dummy = 0;
+   }
+   else
+      rdcount++;
+   timeout = wait_for_pin(adap, &status);
+   if (timeout) {
+      printk("i2c-algo-pcf.o: i2c_read: i2c_inb timed out.\n");
+      return (-1);
+   }
+   return (rdcount);
+}
+
+
+static inline int pcf_doAddress(struct i2c_algo_pcf_data *adap, struct i2c_msg *msg,
+			 int retries) 
+{
+	unsigned short flags = msg->flags;
+	unsigned char addr;
+	int ret;
+	if ( (flags & I2C_M_TEN)  ) { 
+		/* a ten bit address */
+                addr = 0xf0 | (( msg->addr >> 7) & 0x03);
+		DEB2(printk("addr0: %d\n",addr));
+		/* try extended address code...*/
+		ret = try_address(adap, addr, retries);
+		if (ret!=1) {
+			printk("died at extended address code.\n");
+			return -EREMOTEIO;
+		}
+		/* the remaining 8 bit address */
+		i2c_outb(adap,msg->addr & 0x7f);
+/* Status check comes here */
+		if (ret != 1) {
+			printk("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(adap, addr, retries);
+			if (ret!=1) {
+				printk("died at extended address code.\n");
+				return -EREMOTEIO;
+			}
+		}
+	} else {		/* normal 7bit address	*/
+		addr = ( msg->addr << 1 );
+		if (flags & I2C_M_RD )
+			addr |= 1;
+		i2c_outb(adap, addr);
+	}
+	return 0;
+}
+
+static int pcf_xfer(struct i2c_adapter *i2c_adap,
+		    struct i2c_msg msgs[], 
+		    int num)
+{
+   struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+   struct i2c_msg *pmsg;
+   int i, ret, timeout, status;
+
+   timeout = wait_for_bb(adap);
+   if (timeout) {
+      DEB2(printk("i2c-algo-pcf.o: Timeout waiting for BB in pcf_xfer\n");)
+      return -EIO;
+   }
+   pmsg = &msgs[0];
+   ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
+   i2c_start(adap);
+
+   for (i=0; i<num; i++) {
+      DEB3(printk("i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
+		  i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
+      timeout = wait_for_pin(adap, &status);
+      if (timeout) {
+	 DEB2(printk("i2c-algo-pcf.o: Timeout waiting for PIN(1) in pcf_xfer\n");)
+	 i2c_stop(adap);
+	 return (-EREMOTEIO);
+      }
+      if (status & I2C_PCF_LRB) {
+	 i2c_stop(adap);
+	 DEB2(printk("i2c-algo-pcf.o: NAK from device adr %#2x msg #%d\n"
+			       ,msgs[i].addr,i));
+	 return -EREMOTEIO;
+      }
+      if (pmsg->flags & I2C_M_RD ) {
+	 /* read bytes into buffer*/
+	 ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len);
+	 DEB2(printk("i2c-algo-pcf.o: read %d bytes.\n",ret));
+      } else {
+	 /* write bytes from buffer */
+	 ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len);
+	 DEB2(printk("i2c-algo-pcf.o: wrote %d bytes.\n",ret));
+      }
+      if (i == (num-1)) {
+	 i2c_stop(adap);	 
+      }
+      else {
+	 i2c_repstart(adap);
+      }
+      if (pmsg->flags & I2C_M_RD ) {
+	 pmsg->buf[pmsg->len-1] =  i2c_inb(adap);
+      }
+      if (i != (num-1)) {
+	 pmsg = &msgs[0];
+	 ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
+	 timeout = wait_for_pin(adap, &status);
+	 if (timeout) {
+	    DEB2(printk("i2c-algo-pcf.o: Timeout waiting for PIN(2) in pcf_xfer\n");)
+	    return (-EREMOTEIO);
+	 }
+	 if (status & I2C_PCF_LRB) {
+	    i2c_stop(adap);
+	    DEB2(printk("i2c-algo-pcf.o: No LRB(2) in pcf_xfer\n");)
+	    return (-EREMOTEIO);
+	 }
+      }
+   }
+   return (num);
+}
+
+
+static int algo_control(struct i2c_adapter *adapter, 
+	unsigned int cmd, unsigned long arg)
+{
+	return 0;
+}
+
+static u32 pcf_func(struct i2c_adapter *adap)
+{
+        return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
+}
+
+/* -----exported algorithm data: -------------------------------------	*/
+
+static struct i2c_algorithm pcf_algo = {
+	"PCF8584 algorithm",
+	I2C_ALGO_PCF,
+	pcf_xfer,
+	NULL,
+	NULL,				/* slave_xmit		*/
+	NULL,				/* slave_recv		*/
+	algo_control,			/* ioctl		*/
+	pcf_func,                       /* functionality        */
+};
+
+/* 
+ * registering functions to load algorithms at runtime 
+ */
+int i2c_pcf_add_bus(struct i2c_adapter *adap)
+{
+	int i, status;
+	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
+
+	if (pcf_test) {
+		int ret = test_bus(pcf_adap, adap->name);
+		if (ret<0)
+			return -ENODEV;
+	}
+
+	DEB2(printk("i2c-algo-pcf.o: hw routines for %s registered.\n",adap->name));
+
+	/* register new adapter to i2c module... */
+
+	adap->id |= pcf_algo.id;
+	adap->algo = &pcf_algo;
+
+	adap->timeout = 100;	/* default values, should	*/
+	adap->retries = 3;		/* be replaced by defines	*/
+
+#ifdef MODULE
+	MOD_INC_USE_COUNT;
+#endif
+
+	i2c_add_adapter(adap);
+	pcf_init_8584(pcf_adap);
+
+	/* scan bus */
+	if (pcf_scan) {
+	   printk(KERN_INFO " i2c-algo-pcf.o: scanning bus %s.\n", adap->name);
+	   for (i = 0x00; i < 0xff; i+=2) {
+	      i2c_outb(pcf_adap, i);
+	      i2c_start(pcf_adap);
+	      if ((wait_for_pin(pcf_adap, &status) >= 0) && 
+		  ((status && I2C_PCF_LRB) == 0)) { 
+		 printk("(%02x)",i>>1); 
+	      } else {
+		 printk("."); 
+	      }
+	      i2c_stop(pcf_adap);
+	      udelay(pcf_adap->udelay);
+	   }
+	   printk("\n");
+	}
+	return 0;
+}
+
+
+int i2c_pcf_del_bus(struct i2c_adapter *adap)
+{
+	i2c_del_adapter(adap);
+	DEB2(printk("i2c-algo-pcf.o: adapter unregistered: %s\n",adap->name));
+
+#ifdef MODULE
+	MOD_DEC_USE_COUNT;
+#endif
+	return 0;
+}
+
+int __init i2c_algo_pcf_init (void)
+{
+        printk("i2c-algo-pcf.o: i2c pcf8584 algorithm module\n");
+	return 0;
+}
+
+
+EXPORT_SYMBOL(i2c_pcf_add_bus);
+EXPORT_SYMBOL(i2c_pcf_del_bus);
+
+#ifdef MODULE
+MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
+MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
+
+MODULE_PARM(pcf_test, "i");
+MODULE_PARM(pcf_scan, "i");
+MODULE_PARM(i2c_debug,"i");
+
+MODULE_PARM_DESC(pcf_test, "Test if the I2C bus is available");
+MODULE_PARM_DESC(pcf_scan, "Scan for active chips on the bus");
+MODULE_PARM_DESC(i2c_debug,"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
+
+
+int init_module(void) 
+{
+	return i2c_algo_pcf_init();
+}
+
+void cleanup_module(void) 
+{
+}
+#endif