#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/smp_lock.h>
#include <linux/spi/spi.h>
#include <linux/spi/spidev.h>
mutex_lock(&spidev->buf_lock);
status = spidev_sync_read(spidev, count);
- if (status == 0) {
+ if (status > 0) {
unsigned long missing;
- missing = copy_to_user(buf, spidev->buffer, count);
- if (count && missing == count)
+ missing = copy_to_user(buf, spidev->buffer, status);
+ if (missing == status)
status = -EFAULT;
else
- status = count - missing;
+ status = status - missing;
}
mutex_unlock(&spidev->buf_lock);
missing = copy_from_user(spidev->buffer, buf, count);
if (missing == 0) {
status = spidev_sync_write(spidev, count);
- if (status == 0)
- status = count;
} else
status = -EFAULT;
mutex_unlock(&spidev->buf_lock);
* We walk the array of user-provided transfers, using each one
* to initialize a kernel version of the same transfer.
*/
- mutex_lock(&spidev->buf_lock);
buf = spidev->buffer;
total = 0;
for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
status = total;
done:
- mutex_unlock(&spidev->buf_lock);
kfree(k_xfers);
return status;
}
-static int
-spidev_ioctl(struct inode *inode, struct file *filp,
- unsigned int cmd, unsigned long arg)
+static long
+spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
int err = 0;
int retval = 0;
if (spi == NULL)
return -ESHUTDOWN;
+ /* use the buffer lock here for triple duty:
+ * - prevent I/O (from us) so calling spi_setup() is safe;
+ * - prevent concurrent SPI_IOC_WR_* from morphing
+ * data fields while SPI_IOC_RD_* reads them;
+ * - SPI_IOC_MESSAGE needs the buffer locked "normally".
+ */
+ mutex_lock(&spidev->buf_lock);
+
switch (cmd) {
/* read requests */
case SPI_IOC_RD_MODE:
kfree(ioc);
break;
}
+
+ mutex_unlock(&spidev->buf_lock);
spi_dev_put(spi);
return retval;
}
struct spidev_data *spidev;
int status = -ENXIO;
+ lock_kernel();
mutex_lock(&device_list_lock);
list_for_each_entry(spidev, &device_list, device_entry) {
pr_debug("spidev: nothing for minor %d\n", iminor(inode));
mutex_unlock(&device_list_lock);
+ unlock_kernel();
return status;
}
*/
.write = spidev_write,
.read = spidev_read,
- .ioctl = spidev_ioctl,
+ .unlocked_ioctl = spidev_ioctl,
.open = spidev_open,
.release = spidev_release,
};
struct device *dev;
spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
- dev = device_create(spidev_class, &spi->dev, spidev->devt,
+ dev = device_create_drvdata(spidev_class, &spi->dev,
+ spidev->devt, spidev,
"spidev%d.%d",
spi->master->bus_num, spi->chip_select);
status = IS_ERR(dev) ? PTR_ERR(dev) : 0;
}
if (status == 0) {
set_bit(minor, minors);
- spi_set_drvdata(spi, spidev);
list_add(&spidev->device_entry, &device_list);
}
mutex_unlock(&device_list_lock);