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-rw-r--r--cpukit/dev/i2c/i2c-bus.c45
1 files changed, 40 insertions, 5 deletions
diff --git a/cpukit/dev/i2c/i2c-bus.c b/cpukit/dev/i2c/i2c-bus.c
index 472222c4ab..618a817b1a 100644
--- a/cpukit/dev/i2c/i2c-bus.c
+++ b/cpukit/dev/i2c/i2c-bus.c
@@ -31,6 +31,11 @@
#include <stdlib.h>
#include <string.h>
+int i2c_bus_try_obtain(i2c_bus *bus)
+{
+ return rtems_recursive_mutex_try_lock(&bus->mutex);
+}
+
void i2c_bus_obtain(i2c_bus *bus)
{
rtems_recursive_mutex_lock(&bus->mutex);
@@ -41,7 +46,12 @@ void i2c_bus_release(i2c_bus *bus)
rtems_recursive_mutex_unlock(&bus->mutex);
}
-int i2c_bus_transfer(i2c_bus *bus, i2c_msg *msgs, uint32_t msg_count)
+int i2c_bus_do_transfer(
+ i2c_bus *bus,
+ i2c_msg *msgs,
+ uint32_t msg_count,
+ uint32_t flags
+)
{
int err;
uint32_t i;
@@ -63,13 +73,24 @@ int i2c_bus_transfer(i2c_bus *bus, i2c_msg *msgs, uint32_t msg_count)
}
}
- i2c_bus_obtain(bus);
+ if ((flags & I2C_BUS_NOBLOCK) != 0) {
+ if (i2c_bus_try_obtain(bus) != 0) {
+ return -EAGAIN;
+ }
+ } else {
+ i2c_bus_obtain(bus);
+ }
err = (*bus->transfer)(bus, msgs, msg_count);
i2c_bus_release(bus);
return err;
}
+int i2c_bus_transfer(i2c_bus *bus, i2c_msg *msgs, uint32_t msg_count)
+{
+ return i2c_bus_do_transfer(bus, msgs, msg_count, 0);
+}
+
static ssize_t i2c_bus_read(
rtems_libio_t *iop,
void *buffer,
@@ -84,12 +105,17 @@ static ssize_t i2c_bus_read(
.buf = buffer
};
int err;
+ unsigned flags = 0;
if (bus->ten_bit_address) {
msg.flags |= I2C_M_TEN;
}
- err = i2c_bus_transfer(bus, &msg, 1);
+ if (rtems_libio_iop_is_no_delay(iop)) {
+ flags |= I2C_BUS_NOBLOCK;
+ }
+
+ err = i2c_bus_do_transfer(bus, &msg, 1, flags);
if (err == 0) {
return msg.len;
} else {
@@ -111,12 +137,17 @@ static ssize_t i2c_bus_write(
.buf = RTEMS_DECONST(void *, buffer)
};
int err;
+ unsigned flags = 0;
if (bus->ten_bit_address) {
msg.flags |= I2C_M_TEN;
}
- err = i2c_bus_transfer(bus, &msg, 1);
+ if (rtems_libio_iop_is_no_delay(iop)) {
+ flags |= I2C_BUS_NOBLOCK;
+ }
+
+ err = i2c_bus_do_transfer(bus, &msg, 1, flags);
if (err == 0) {
return msg.len;
} else {
@@ -133,12 +164,16 @@ static int i2c_bus_ioctl(
i2c_bus *bus = IMFS_generic_get_context_by_iop(iop);
i2c_rdwr_ioctl_data *rdwr;
int err;
+ unsigned flags = 0;
switch (command) {
case I2C_RDWR:
rdwr = arg;
if (rdwr->nmsgs > 0) {
- err = i2c_bus_transfer(bus, rdwr->msgs, rdwr->nmsgs);
+ if (rtems_libio_iop_is_no_delay(iop)) {
+ flags |= I2C_BUS_NOBLOCK;
+ }
+ err = i2c_bus_do_transfer(bus, rdwr->msgs, rdwr->nmsgs, flags);
} else {
err = 0;
}