1 files changed, 507 insertions, 0 deletions

diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
new file mode 100644
index 000000000000..8d087dac32af
--- /dev/null
+++ b/drivers/i2c/algos/i2c-algo-pcf.c
@@ -0,0 +1,507 @@
+/* ------------------------------------------------------------------------- */
+/* i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters                 */
+/* ------------------------------------------------------------------------- */
+/*   Copyright (C) 1995-1997 Simon G. Vogl
+                   1998-2000 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 
+   Frodo Looijaard <frodol@dds.nl> ,and also from Martin Bailey
+   <mbailey@littlefeet-inc.com> */
+
+/* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
+   messages, proper stop/repstart signaling during receive,
+   added detect code */
+
+#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/i2c.h>
+#include <linux/i2c-algo-pcf.h>
+#include "i2c-algo-pcf.h"
+
+
+#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
+
+/* module parameters:
+ */
+static int i2c_debug;
+
+/* --- 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 -------------------------------------- */
+
+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);
+#ifndef STUB_I2C
+        while (timeout-- && !(status & I2C_PCF_BB)) {
+                udelay(100); /* wait for 100 us */
+                status = get_pcf(adap, 1);
+        }
+#endif
+        if (timeout <= 0) {
+                printk(KERN_ERR "Timeout waiting for Bus Busy\n");
+        }
+        
+        return (timeout<=0);
+}
+
+
+static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {
+
+        int timeout = DEF_TIMEOUT;
+
+        *status = get_pcf(adap, 1);
+#ifndef STUB_I2C
+        while (timeout-- && (*status & I2C_PCF_PIN)) {
+                adap->waitforpin();
+                *status = get_pcf(adap, 1);
+        }
+        if (*status & I2C_PCF_LAB) {
+                DEB2(printk(KERN_INFO 
+                        "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
+                         *status));
+                /* Cleanup from LAB-- reset and enable ESO.
+                 * This resets the PCF8584; since we've lost the bus, no
+                 * further attempts should be made by callers to clean up 
+                 * (no i2c_stop() etc.)
+                 */
+                set_pcf(adap, 1, I2C_PCF_PIN);
+                set_pcf(adap, 1, I2C_PCF_ESO);
+                /* TODO: we should pause for a time period sufficient for any
+                 * running I2C transaction to complete-- the arbitration
+                 * logic won't work properly until the next START is seen.
+                 */
+                DEB2(printk(KERN_INFO 
+                        "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n", 
+                        get_pcf(adap,1)));
+                return(-EINTR);
+        }
+#endif
+        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.
+ *
+ * vdovikin: added detect code for PCF8584
+ */
+static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
+{
+        unsigned char temp;
+
+        DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n", get_pcf(adap, 1)));
+
+        /* S1=0x80: S0 selected, serial interface off */
+        set_pcf(adap, 1, I2C_PCF_PIN);
+        /* check to see S1 now used as R/W ctrl -
+           PCF8584 does that when ESO is zero */
+        if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
+                return -ENXIO; /* definetly not PCF8584 */
+        }
+
+        /* load own address in S0, effective address is (own << 1)      */
+        i2c_outb(adap, get_own(adap));
+        /* check it's really written */
+        if ((temp = i2c_inb(adap)) != get_own(adap)) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
+                return -ENXIO;
+        }
+
+        /* S1=0xA0, next byte in S2                                     */
+        set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
+        /* check to see S2 now selected */
+        if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
+                return -ENXIO;
+        }
+
+        /* load clock register S2                                       */
+        i2c_outb(adap, get_clock(adap));
+        /* check it's really written, the only 5 lowest bits does matter */
+        if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
+                return -ENXIO;
+        }
+
+        /* Enable serial interface, idle, S0 selected                   */
+        set_pcf(adap, 1, I2C_PCF_IDLE);
+
+        /* check to see PCF is really idled and we can access status register */
+        if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
+                return -ENXIO;
+        }
+        
+        printk(KERN_DEBUG "i2c-algo-pcf.o: deteted and initialized PCF8584.\n");
+
+        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;
+        int wfp;
+        for (i=0;i<retries;i++) {
+                i2c_outb(adap, addr);
+                i2c_start(adap);
+                status = get_pcf(adap, 1);
+                if ((wfp = wait_for_pin(adap, &status)) >= 0) {
+                        if ((status & I2C_PCF_LRB) == 0) { 
+                                i2c_stop(adap);
+                                break;  /* success! */
+                        }
+                }
+                if (wfp == -EINTR) {
+                        /* arbitration lost */
+                        udelay(adap->udelay);
+                        return -EINTR;
+                }
+                i2c_stop(adap);
+                udelay(adap->udelay);
+        }
+        DEB2(if (i) printk(KERN_DEBUG "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, int last)
+{
+        struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+        int wrcount, status, timeout;
+    
+        for (wrcount=0; wrcount<count; ++wrcount) {
+                DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
+                                buf[wrcount]&0xff));
+                i2c_outb(adap, buf[wrcount]);
+                timeout = wait_for_pin(adap, &status);
+                if (timeout) {
+                        if (timeout == -EINTR) {
+                                /* arbitration lost */
+                                return -EINTR;
+                        }
+                        i2c_stop(adap);
+                        dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
+                        return -EREMOTEIO; /* got a better one ?? */
+                }
+#ifndef STUB_I2C
+                if (status & I2C_PCF_LRB) {
+                        i2c_stop(adap);
+                        dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
+                        return -EREMOTEIO; /* got a better one ?? */
+                }
+#endif
+        }
+        if (last) {
+                i2c_stop(adap);
+        }
+        else {
+                i2c_repstart(adap);
+        }
+
+        return (wrcount);
+}
+
+
+static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
+                         int count, int last)
+{
+        int i, status;
+        struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
+        int wfp;
+
+        /* increment number of bytes to read by one -- read dummy byte */
+        for (i = 0; i <= count; i++) {
+
+                if ((wfp = wait_for_pin(adap, &status))) {
+                        if (wfp == -EINTR) {
+                                /* arbitration lost */
+                                return -EINTR;
+                        }
+                        i2c_stop(adap);
+                        dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
+                        return (-1);
+                }
+
+#ifndef STUB_I2C
+                if ((status & I2C_PCF_LRB) && (i != count)) {
+                        i2c_stop(adap);
+                        dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
+                        return (-1);
+                }
+#endif
+                
+                if (i == count - 1) {
+                        set_pcf(adap, 1, I2C_PCF_ESO);
+                } else 
+                if (i == count) {
+                        if (last) {
+                                i2c_stop(adap);
+                        } else {
+                                i2c_repstart(adap);
+                        }
+                };
+
+                if (i) {
+                        buf[i - 1] = i2c_inb(adap);
+                } else {
+                        i2c_inb(adap); /* dummy read */
+                }
+        }
+
+        return (i - 1);
+}
+
+
+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(KERN_DEBUG "addr0: %d\n",addr));
+                /* try extended address code...*/
+                ret = try_address(adap, addr, retries);
+                if (ret!=1) {
+                        printk(KERN_ERR "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(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(adap, addr, retries);
+                        if (ret!=1) {
+                                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;
+                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;
+        int ret=0, timeout, status;
+    
+
+        /* Check for bus busy */
+        timeout = wait_for_bb(adap);
+        if (timeout) {
+                DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
+                            "Timeout waiting for BB in pcf_xfer\n");)
+                return -EIO;
+        }
+        
+        for (i = 0;ret >= 0 && i < num; i++) {
+                pmsg = &msgs[i];
+
+                DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
+                     pmsg->flags & I2C_M_RD ? "read" : "write",
+                     pmsg->len, pmsg->addr, i + 1, num);)
+    
+                ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
+
+                /* Send START */
+                if (i == 0) {
+                        i2c_start(adap); 
+                }
+    
+                /* Wait for PIN (pending interrupt NOT) */
+                timeout = wait_for_pin(adap, &status);
+                if (timeout) {
+                        if (timeout == -EINTR) {
+                                /* arbitration lost */
+                                return (-EINTR);
+                        }
+                        i2c_stop(adap);
+                        DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
+                                    "for PIN(1) in pcf_xfer\n");)
+                        return (-EREMOTEIO);
+                }
+    
+#ifndef STUB_I2C
+                /* Check LRB (last rcvd bit - slave ack) */
+                if (status & I2C_PCF_LRB) {
+                        i2c_stop(adap);
+                        DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
+                        return (-EREMOTEIO);
+                }
+#endif
+    
+                DEB3(printk(KERN_DEBUG "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);)
+    
+                /* Read */
+                if (pmsg->flags & I2C_M_RD) {
+                        /* read bytes into buffer*/
+                        ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
+                                            (i + 1 == num));
+        
+                        if (ret != pmsg->len) {
+                                DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
+                                            "only read %d bytes.\n",ret));
+                        } else {
+                                DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
+                        }
+                } else { /* Write */
+                        ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
+                                            (i + 1 == num));
+        
+                        if (ret != pmsg->len) {
+                                DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
+                                            "only wrote %d bytes.\n",ret));
+                        } else {
+                                DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
+                        }
+                }
+        }
+
+        return (i);
+}
+
+static u32 pcf_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 pcf_algo = {
+        .name           = "PCF8584 algorithm",
+        .id             = I2C_ALGO_PCF,
+        .master_xfer    = pcf_xfer,
+        .functionality  = pcf_func,
+};
+
+/* 
+ * registering functions to load algorithms at runtime 
+ */
+int i2c_pcf_add_bus(struct i2c_adapter *adap)
+{
+        struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
+        int rval;
+
+        DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
+
+        /* 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       */
+
+        rval = pcf_init_8584(pcf_adap);
+        if (!rval)
+                i2c_add_adapter(adap);
+        return rval;
+}
+
+
+int i2c_pcf_del_bus(struct i2c_adapter *adap)
+{
+        return i2c_del_adapter(adap);
+}
+
+EXPORT_SYMBOL(i2c_pcf_add_bus);
+EXPORT_SYMBOL(i2c_pcf_del_bus);
+
+MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
+MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
+MODULE_LICENSE("GPL");
+
+module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(i2c_debug,
+        "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");