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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pcf.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-pcf.c261
1 files changed, 121 insertions, 140 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
index 3e01992230b..7ce75775ec7 100644
--- a/drivers/i2c/algos/i2c-algo-pcf.c
+++ b/drivers/i2c/algos/i2c-algo-pcf.c
@@ -1,31 +1,30 @@
-/* ------------------------------------------------------------------------- */
-/* 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 */
+/*
+ * 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>
@@ -38,17 +37,18 @@
#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 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:
+/*
+ * module parameters:
*/
static int i2c_debug;
-/* --- setting states on the bus with the right timing: --------------- */
+/* 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)
@@ -57,22 +57,21 @@ static int i2c_debug;
#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
#define i2c_inb(adap) adap->getpcf(adap->data, 0)
-/* --- other auxiliary functions -------------------------------------- */
+/* other auxiliary functions */
-static void i2c_start(struct i2c_algo_pcf_data *adap)
+static void i2c_start(struct i2c_algo_pcf_data *adap)
{
- DEBPROTO(printk("S "));
+ DEBPROTO(printk(KERN_DEBUG "S "));
set_pcf(adap, 1, I2C_PCF_START);
}
-static void i2c_repstart(struct i2c_algo_pcf_data *adap)
+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)
+static void i2c_stop(struct i2c_algo_pcf_data *adap)
{
DEBPROTO(printk("P\n"));
set_pcf(adap, 1, I2C_PCF_STOP);
@@ -82,17 +81,17 @@ static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
{
DEB2(printk(KERN_INFO
"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
- *status));
-
- /* Cleanup from LAB -- reset and enable ESO.
+ *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);
-
- /* We pause for a time period sufficient for any running
+ /*
+ * We 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.
* It is assumed the bus driver or client has set a proper value.
@@ -108,48 +107,50 @@ static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status)
get_pcf(adap, 1)));
}
-static int wait_for_bb(struct i2c_algo_pcf_data *adap) {
+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)) {
+
+ while (!(status & I2C_PCF_BB) && --timeout) {
udelay(100); /* wait for 100 us */
status = get_pcf(adap, 1);
}
-#endif
- if (timeout <= 0) {
+
+ if (timeout == 0) {
printk(KERN_ERR "Timeout waiting for Bus Busy\n");
+ return -ETIMEDOUT;
}
-
- return (timeout<=0);
-}
+ return 0;
+}
-static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {
+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)) {
+
+ while ((*status & I2C_PCF_PIN) && --timeout) {
adap->waitforpin(adap->data);
*status = get_pcf(adap, 1);
}
if (*status & I2C_PCF_LAB) {
handle_lab(adap, status);
- return(-EINTR);
+ return -EINTR;
}
-#endif
- if (timeout <= 0)
- return(-1);
- else
- return(0);
+
+ if (timeout == 0)
+ return -ETIMEDOUT;
+
+ 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
@@ -164,18 +165,21 @@ 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)));
+ 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 */
+ /*
+ * 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) */
+ /* 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)) {
@@ -183,7 +187,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
return -ENXIO;
}
- /* S1=0xA0, next byte in S2 */
+ /* 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) {
@@ -191,7 +195,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
return -ENXIO;
}
- /* load clock register S2 */
+ /* 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)) {
@@ -199,7 +203,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
return -ENXIO;
}
- /* Enable serial interface, idle, S0 selected */
+ /* 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 */
@@ -207,57 +211,47 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
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: detected and initialized PCF8584.\n");
return 0;
}
-
-/* ----- Utility functions
- */
-
static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
- int count, int last)
+ 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));
+ buf[wrcount] & 0xff));
i2c_outb(adap, buf[wrcount]);
timeout = wait_for_pin(adap, &status);
if (timeout) {
- if (timeout == -EINTR) {
- /* arbitration lost */
- return -EINTR;
- }
+ if (timeout == -EINTR)
+ return -EINTR; /* arbitration lost */
+
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) {
+ if (last)
i2c_stop(adap);
- }
- else {
+ else
i2c_repstart(adap);
- }
- return (wrcount);
+ return wrcount;
}
-
static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
- int count, int last)
+ int count, int last)
{
int i, status;
struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
@@ -267,42 +261,36 @@ static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
for (i = 0; i <= count; i++) {
if ((wfp = wait_for_pin(adap, &status))) {
- if (wfp == -EINTR) {
- /* arbitration lost */
- return -EINTR;
- }
+ if (wfp == -EINTR)
+ return -EINTR; /* arbitration lost */
+
i2c_stop(adap);
dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
- return (-1);
+ 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);
+ return -1;
}
-#endif
-
+
if (i == count - 1) {
set_pcf(adap, 1, I2C_PCF_ESO);
- } else
- if (i == count) {
- if (last) {
+ } else if (i == count) {
+ if (last)
i2c_stop(adap);
- } else {
+ else
i2c_repstart(adap);
- }
- };
+ }
- if (i) {
+ if (i)
buf[i - 1] = i2c_inb(adap);
- } else {
+ else
i2c_inb(adap); /* dummy read */
- }
}
- return (i - 1);
+ return i - 1;
}
@@ -323,14 +311,14 @@ static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
}
static int pcf_xfer(struct i2c_adapter *i2c_adap,
- struct i2c_msg *msgs,
+ 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;
-
+
if (adap->xfer_begin)
adap->xfer_begin(adap->data);
@@ -338,25 +326,24 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
timeout = wait_for_bb(adap);
if (timeout) {
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
- "Timeout waiting for BB in pcf_xfer\n");)
+ "Timeout waiting for BB in pcf_xfer\n");)
i = -EIO;
goto out;
}
-
+
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);)
-
+ pmsg->len, pmsg->addr, i + 1, num);)
+
ret = pcf_doAddress(adap, pmsg);
/* Send START */
- if (i == 0) {
- i2c_start(adap);
- }
-
+ if (i == 0)
+ i2c_start(adap);
+
/* Wait for PIN (pending interrupt NOT) */
timeout = wait_for_pin(adap, &status);
if (timeout) {
@@ -371,8 +358,7 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
i = -EREMOTEIO;
goto out;
}
-
-#ifndef STUB_I2C
+
/* Check LRB (last rcvd bit - slave ack) */
if (status & I2C_PCF_LRB) {
i2c_stop(adap);
@@ -380,27 +366,24 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
i = -EREMOTEIO;
goto out;
}
-#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));
-
+ (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 */
+ } else {
ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
- (i + 1 == num));
-
+ (i + 1 == num));
+
if (ret != pmsg->len) {
DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
"only wrote %d bytes.\n",ret));
@@ -413,24 +396,23 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap,
out:
if (adap->xfer_end)
adap->xfer_end(adap->data);
- return (i);
+ return i;
}
static u32 pcf_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_PROTOCOL_MANGLING;
}
-/* -----exported algorithm data: ------------------------------------- */
-
+/* exported algorithm data: */
static const struct i2c_algorithm pcf_algo = {
.master_xfer = pcf_xfer,
.functionality = pcf_func,
};
-/*
- * registering functions to load algorithms at runtime
+/*
+ * registering functions to load algorithms at runtime
*/
int i2c_pcf_add_bus(struct i2c_adapter *adap)
{
@@ -441,7 +423,6 @@ int i2c_pcf_add_bus(struct i2c_adapter *adap)
/* register new adapter to i2c module... */
adap->algo = &pcf_algo;
- adap->timeout = 100;
if ((rval = pcf_init_8584(pcf_adap)))
return rval;
@@ -458,4 +439,4 @@ 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");
+ "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-01 06:07:17 +0000