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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-bit.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c110
1 files changed, 71 insertions, 39 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index e25e13980af..65ef9664d5d 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -15,17 +15,16 @@
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.
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ MA 02110-1301 USA.
* ------------------------------------------------------------------------- */
/* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki
- <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */
+ <kmalkki@cc.hut.fi> and Jean Delvare <jdelvare@suse.de> */
#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>
@@ -48,8 +47,8 @@
/* ----- global variables --------------------------------------------- */
static int bit_test; /* see if the line-setting functions work */
-module_param(bit_test, bool, 0);
-MODULE_PARM_DESC(bit_test, "Test the lines of the bus to see if it is stuck");
+module_param(bit_test, int, S_IRUGO);
+MODULE_PARM_DESC(bit_test, "lines testing - 0 off; 1 report; 2 fail if stuck");
#ifdef DEBUG
static int i2c_debug = 1;
@@ -104,9 +103,15 @@ static int sclhi(struct i2c_algo_bit_data *adap)
* chips may hold it low ("clock stretching") while they
* are processing data internally.
*/
- if (time_after(jiffies, start + adap->timeout))
+ if (time_after(jiffies, start + adap->timeout)) {
+ /* Test one last time, as we may have been preempted
+ * between last check and timeout test.
+ */
+ if (getscl(adap))
+ break;
return -ETIMEDOUT;
- cond_resched();
+ }
+ cpu_relax();
}
#ifdef DEBUG
if (jiffies != start && i2c_debug >= 3)
@@ -233,9 +238,17 @@ static int i2c_inb(struct i2c_adapter *i2c_adap)
* 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)
+static int test_bus(struct i2c_adapter *i2c_adap)
{
- int scl, sda;
+ struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+ const char *name = i2c_adap->name;
+ int scl, sda, ret;
+
+ if (adap->pre_xfer) {
+ ret = adap->pre_xfer(i2c_adap);
+ if (ret < 0)
+ return -ENODEV;
+ }
if (adap->getscl == NULL)
pr_info("%s: Testing SDA only, SCL is not readable\n", name);
@@ -243,7 +256,9 @@ static int test_bus(struct i2c_algo_bit_data *adap, char *name)
sda = getsda(adap);
scl = (adap->getscl == NULL) ? 1 : getscl(adap);
if (!scl || !sda) {
- printk(KERN_WARNING "%s: bus seems to be busy\n", name);
+ printk(KERN_WARNING
+ "%s: bus seems to be busy (scl=%d, sda=%d)\n",
+ name, scl, sda);
goto bailout;
}
@@ -298,11 +313,19 @@ static int test_bus(struct i2c_algo_bit_data *adap, char *name)
"while pulling SCL high!\n", name);
goto bailout;
}
+
+ if (adap->post_xfer)
+ adap->post_xfer(i2c_adap);
+
pr_info("%s: Test OK\n", name);
return 0;
bailout:
sdahi(adap);
sclhi(adap);
+
+ if (adap->post_xfer)
+ adap->post_xfer(i2c_adap);
+
return -ENODEV;
}
@@ -426,7 +449,7 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
acknak(i2c_adap, 0);
dev_err(&i2c_adap->dev, "readbytes: invalid "
"block length (%d)\n", inval);
- return -EREMOTEIO;
+ return -EPROTO;
}
/* The original count value accounts for the extra
bytes, that is, either 1 for a regular transaction,
@@ -455,7 +478,7 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
* 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
+ * -x an error occurred (like: -ENXIO if the device did not answer, or
* -ETIMEDOUT, for example if the lines are stuck...)
*/
static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
@@ -471,21 +494,21 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
if (flags & I2C_M_TEN) {
/* a ten bit address */
- addr = 0xf0 | ((msg->addr >> 7) & 0x03);
+ addr = 0xf0 | ((msg->addr >> 7) & 0x06);
bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr);
/* try extended address code...*/
ret = try_address(i2c_adap, addr, retries);
if ((ret != 1) && !nak_ok) {
dev_err(&i2c_adap->dev,
"died at extended address code\n");
- return -EREMOTEIO;
+ return -ENXIO;
}
/* the remaining 8 bit address */
- ret = i2c_outb(i2c_adap, msg->addr & 0x7f);
+ ret = i2c_outb(i2c_adap, msg->addr & 0xff);
if ((ret != 1) && !nak_ok) {
/* the chip did not ack / xmission error occurred */
dev_err(&i2c_adap->dev, "died at 2nd address code\n");
- return -EREMOTEIO;
+ return -ENXIO;
}
if (flags & I2C_M_RD) {
bit_dbg(3, &i2c_adap->dev, "emitting repeated "
@@ -497,7 +520,7 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
if ((ret != 1) && !nak_ok) {
dev_err(&i2c_adap->dev,
"died at repeated address code\n");
- return -EREMOTEIO;
+ return -EIO;
}
}
} else { /* normal 7bit address */
@@ -522,6 +545,12 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
int i, ret;
unsigned short nak_ok;
+ if (adap->pre_xfer) {
+ ret = adap->pre_xfer(i2c_adap);
+ if (ret < 0)
+ return ret;
+ }
+
bit_dbg(3, &i2c_adap->dev, "emitting start condition\n");
i2c_start(adap);
for (i = 0; i < num; i++) {
@@ -549,7 +578,7 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
ret, ret == 1 ? "" : "s");
if (ret < pmsg->len) {
if (ret >= 0)
- ret = -EREMOTEIO;
+ ret = -EIO;
goto bailout;
}
} else {
@@ -560,7 +589,7 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
ret, ret == 1 ? "" : "s");
if (ret < pmsg->len) {
if (ret >= 0)
- ret = -EREMOTEIO;
+ ret = -EIO;
goto bailout;
}
}
@@ -570,12 +599,15 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
bailout:
bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n");
i2c_stop(adap);
+
+ if (adap->post_xfer)
+ adap->post_xfer(i2c_adap);
return ret;
}
static u32 bit_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
@@ -584,21 +616,24 @@ static u32 bit_func(struct i2c_adapter *adap)
/* -----exported algorithm data: ------------------------------------- */
-static const struct i2c_algorithm i2c_bit_algo = {
+const struct i2c_algorithm i2c_bit_algo = {
.master_xfer = bit_xfer,
.functionality = bit_func,
};
+EXPORT_SYMBOL(i2c_bit_algo);
/*
* registering functions to load algorithms at runtime
*/
-static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
+static int __i2c_bit_add_bus(struct i2c_adapter *adap,
+ int (*add_adapter)(struct i2c_adapter *))
{
struct i2c_algo_bit_data *bit_adap = adap->algo_data;
+ int ret;
if (bit_test) {
- int ret = test_bus(bit_adap, adap->name);
- if (ret < 0)
+ ret = test_bus(adap);
+ if (bit_test >= 2 && ret < 0)
return -ENODEV;
}
@@ -606,30 +641,27 @@ static int i2c_bit_prepare_bus(struct i2c_adapter *adap)
adap->algo = &i2c_bit_algo;
adap->retries = 3;
+ ret = add_adapter(adap);
+ if (ret < 0)
+ return ret;
+
+ /* Complain if SCL can't be read */
+ if (bit_adap->getscl == NULL) {
+ dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n");
+ dev_warn(&adap->dev, "Bus may be unreliable\n");
+ }
return 0;
}
int i2c_bit_add_bus(struct i2c_adapter *adap)
{
- int err;
-
- err = i2c_bit_prepare_bus(adap);
- if (err)
- return err;
-
- return i2c_add_adapter(adap);
+ return __i2c_bit_add_bus(adap, i2c_add_adapter);
}
EXPORT_SYMBOL(i2c_bit_add_bus);
int i2c_bit_add_numbered_bus(struct i2c_adapter *adap)
{
- int err;
-
- err = i2c_bit_prepare_bus(adap);
- if (err)
- return err;
-
- return i2c_add_numbered_adapter(adap);
+ return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter);
}
EXPORT_SYMBOL(i2c_bit_add_numbered_bus);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 06:47:53 +0000