On Sat, Sep 5, 2020 at 7:34 PM Artur Rojek <contact@xxxxxxxxxxxxxx> wrote:
>
> Add a driver for joystick devices connected to ADC controllers
> supporting the Industrial I/O subsystem.
...
> +static int adc_joystick_handle(const void *data, void *private)
> +{
> + struct adc_joystick *joy = private;
> + enum iio_endian endianness;
> + int bytes, msb, val, idx, i;
> + bool sign;
> +
> + bytes = joy->chans[0].channel->scan_type.storagebits >> 3;
> +
> + for (i = 0; i < joy->num_chans; ++i) {
> + idx = joy->chans[i].channel->scan_index;
> + endianness = joy->chans[i].channel->scan_type.endianness;
> + msb = joy->chans[i].channel->scan_type.realbits - 1;
> + sign = (tolower(joy->chans[i].channel->scan_type.sign) == 's');
Redundant parentheses.
> + switch (bytes) {
> + case 1:
> + val = ((const u8 *)data)[idx];
> + break;
> + case 2:
> + if (endianness == IIO_BE)
> + val = be16_to_cpu(((const __be16 *)data)[idx]);
> + else if (endianness == IIO_LE)
> + val = le16_to_cpu(((const __le16 *)data)[idx]);
> + else /* IIO_CPU */
> + val = ((const u16 *)data)[idx];
> + break;
Hmm... I don't like explicit castings to restricted types. On top of
that is it guaranteed that pointer to data will be aligned?
As a solution for the first two I would recommend to use
get_unaligned_be16() / get_unaligned_le16().
The last one is an interesting case and if data can be unaligned needs
to be fixed.
> + default:
> + return -EINVAL;
> + }
> +
> + val >>= joy->chans[i].channel->scan_type.shift;
> + if (sign)
> + val = sign_extend32(val, msb);
> + else
> + val &= GENMASK(msb, 0);
It includes msb. Is it expected?
> + input_report_abs(joy->input, joy->axes[i].code, val);
> + }
> +
> + input_sync(joy->input);
> +
> + return 0;
> +}
...
> +static int adc_joystick_open(struct input_dev *dev)
> +static void adc_joystick_close(struct input_dev *dev)
Just wondering if this is protected against object lifetime cases.
...
> +err:
err_fwnode_put: ?
> + fwnode_handle_put(child);
> + return ret;
...
> + /* Count how many channels we got. NULL terminated. */
> + for (i = 0; joy->chans[i].indio_dev; ++i) {
> + bits = joy->chans[i].channel->scan_type.storagebits;
> + if (!bits || (bits > 16)) {
> + dev_err(dev, "Unsupported channel storage size\n");
> + return -EINVAL;
-ERANGE?
> + }
> + if (bits != joy->chans[0].channel->scan_type.storagebits) {
> + dev_err(dev, "Channels must have equal storage size\n");
> + return -EINVAL;
> + }
> + }
--
With Best Regards,
Andy Shevchenko
