Am Freitag, den 04.05.2018, 08:00 -0500 schrieb David R. Bild :
>
> +config USB_XAPEA00X
> + tristate "Xaptum ENF Access card support (XAP-EA-00x)"
> + depends on USB_SUPPORT && SPI && TCG_TPM
You'd have to know how the device internally works. It would be better
to select SPI.
> +static int xapea00x_br_bulk_write(struct xapea00x_device *dev,
> + struct xapea00x_br_bulk_command *header,
> + const void *data, int len)
> +{
> + u8 *buf;
> + unsigned int pipe;
> + int buf_len, actual_len, retval;
> +
> + buf_len = sizeof(struct xapea00x_br_bulk_command) + len;
> + buf = kzalloc(buf_len, GFP_KERNEL);
> + if (!buf) {
> + retval = -ENOMEM;
> + goto out;
> + }
> +
> + memcpy(buf, header, sizeof(struct xapea00x_br_bulk_command));
> + memcpy(buf + sizeof(struct xapea00x_br_bulk_command), data, len);
> +
> + pipe = usb_sndbulkpipe(dev->udev, dev->bulk_out->bEndpointAddress);
> + retval = usb_bulk_msg(dev->udev, pipe, buf, buf_len, &actual_len,
> + XAPEA00X_BR_USB_TIMEOUT);
> + if (retval)
> + goto free_buf;
WTF?
> +free_buf:
> + kzfree(buf);
> +
> +out:
> + return retval;
> +}
> +
[..]
> +static int xapea00x_spi_setup(struct spi_device *spi)
> +{
> + struct xapea00x_device *dev;
> + int retval;
> +
> + dev = spi_master_get_devdata(spi->master);
> +
> + mutex_lock(&dev->usb_mutex);
> + if (!dev->interface) {
> + retval = -ENODEV;
> + goto out;
> + }
> +
> + /* Verify that this is the TPM device */
> + if (spi->chip_select != 0) {
> + retval = -EINVAL;
> + goto err;
> + }
> +
> + /*
> + * Disable auto chip select for the TPM channel.
> + * Must be done after setting the SPI parameters.
> + */
> + retval = xapea00x_br_disable_cs(dev, 0);
> + if (retval)
> + goto err;
> +
> + /* De-assert chip select for the TPM channel. */
> + retval = xapea00x_br_deassert_cs(dev, 0);
> + if (retval)
> + goto err;
> +
> + goto out;
> +
> +err:
> + dev_err(&dev->interface->dev,
> + "configuring SPI channel failed with %d\n", retval);
That could be a simple 'if' statement.
> +
> +out:
> + mutex_unlock(&dev->usb_mutex);
> + return retval;
> +}
> +
>
[..]
> +/**
> + * xapea00x_spi_probe - Register and configure the SPI master.
> + * @dev: the device whose SPI master to register
> + *
> + * Return: If successful, 0. Otherwise a negative error number.
> + */
> +static int xapea00x_spi_probe(struct xapea00x_device *dev)
> +{
> + struct spi_master *spi_master;
> + int retval;
> +
> + spi_master = spi_alloc_master(&dev->interface->dev, sizeof(void *));
> + if (!spi_master) {
> + retval = -ENOMEM;
> + goto err_out;
> + }
> +
> + spi_master_set_devdata(spi_master, dev);
> +
> + spi_master->min_speed_hz = 93 * 1000 + 800; /* 93.9kHz */
> + spi_master->max_speed_hz = 12 * 1000 * 1000; /* 12 MHz */
> +
> + spi_master->bus_num = -1; /* dynamically assigned */
> + spi_master->num_chipselect = 1;
> + spi_master->mode_bits = SPI_MODE_0;
> +
> + spi_master->flags = 0;
> + spi_master->setup = xapea00x_spi_setup;
> + spi_master->transfer_one_message = xapea00x_spi_transfer_one_message;
> +
> + retval = spi_register_master(spi_master);
> +
> + if (retval)
> + goto free_spi;
> +
> + dev->spi_master = spi_master;
Race condition.
> +
> + return 0;
> +
> +free_spi:
> + spi_master_put(spi_master);
> + dev->spi_master = NULL;
> +
> +err_out:
> + return retval;
> +}
> +
> +struct xapea00x_async_probe {
> + struct work_struct work;
> + struct xapea00x_device *dev;
> +};
> +
> +#define work_to_probe(w) container_of(w, struct xapea00x_async_probe, work)
> +
> +/**
> + * xapea00x_init_async_probe - initialize an async probe with the
> + * specified values.
> + * @probe: pointer to the async_probe to initialize
> + * @dev: pointer to the device to probe
> + * @f: pointer to the probe function
> + */
> +static void xapea00x_init_async_probe(struct xapea00x_async_probe *probe,
> + struct xapea00x_device *dev,
> + void (*f)(struct work_struct *work))
> +{
> + INIT_WORK(&probe->work, f);
> + probe->dev = dev;
> +
> + kref_get(&dev->kref);
> + spi_master_get(dev->spi_master);
> +}
> +
> +/**
> + * xapea00x_cleanup_async_probe - clean up the internals of the async
> + * probe. Call this method after the probe has completed.
> + *
> + * The caller is responsible for freeing the probe itself, if
> + * dynamically allocated.
> + *
> + * @probe: pointer to the async_probe to clean up
> + */
> +static void xapea00x_cleanup_async_probe(struct xapea00x_async_probe *probe)
> +{
> + spi_master_put(probe->dev->spi_master);
> + kref_put(&probe->dev->kref, xapea00x_delete);
> +}
> +
> +static struct spi_board_info tpm_board_info = {
> + .modalias = XAPEA00X_TPM_MODALIAS,
> + .max_speed_hz = 43 * 1000 * 1000, // Hz
Are you hardcoding HZ ?
> + .chip_select = 0,
> + .mode = SPI_MODE_0
> +};
Regards
Oliver
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