On Sun, 7 May 2023 16:56:55 +0200 Mehdi Djait <mehdi.djait.k@xxxxxxxxx> wrote: > Hello Jonathan, > > On Sat, May 06, 2023 at 05:46:51PM +0100, Jonathan Cameron wrote: > > On Fri, 5 May 2023 20:11:33 +0200 > > Mehdi Djait <mehdi.djait.k@xxxxxxxxx> wrote: > > > > > Hello Jonathan, > > > > > > On Mon, May 01, 2023 at 03:56:45PM +0100, Jonathan Cameron wrote: > > > > On Tue, 25 Apr 2023 00:22:27 +0200 > > > > Mehdi Djait <mehdi.djait.k@xxxxxxxxx> wrote: > > > > > > > > > Kionix KX132-1211 is a tri-axis 16-bit accelerometer that can support > > > > > ranges from ±2G to ±16G, digital output through I²C/SPI. > > > > > Add support for basic accelerometer features such as reading acceleration > > > > > via IIO using raw reads, triggered buffer (data-ready), or the WMI IRQ. > > > > > > > > > > Datasheet: https://kionixfs.azureedge.net/en/document/KX132-1211-Technical-Reference-Manual-Rev-5.0.pdf > > > > > Signed-off-by: Mehdi Djait <mehdi.djait.k@xxxxxxxxx> > > > > > > > > Two tiny things inline. > > > > > > > > > +static int kx132_get_fifo_bytes(struct kx022a_data *data) > > > > > +{ > > > > > + struct device *dev = regmap_get_device(data->regmap); > > > > > + __le16 buf_status; > > > > > + int ret, fifo_bytes; > > > > > + > > > > > + ret = regmap_bulk_read(data->regmap, data->chip_info->buf_status1, > > > > > + &buf_status, sizeof(buf_status)); > > > > > + if (ret) { > > > > > + dev_err(dev, "Error reading buffer status\n"); > > > > > + return ret; > > > > > + } > > > > > + > > > > > + fifo_bytes = le16_to_cpu(buf_status); > > > > > + fifo_bytes &= data->chip_info->buf_smp_lvl_mask; > > > > > > > > Slight preference for FIELD_GET() as it saves me checking the mask includes > > > > lowest bits. > > > > > > This will mean I have the remove the chip_info member buf_smp_lvl_mask > > > and use KX132_MASK_BUF_SMP_LVL directly because otherwise the > > > __builtin_constant_p function will cause an error when building. > > > Check: https://elixir.bootlin.com/linux/latest/source/include/linux/bitfield.h#L65 > > > > > > I can change it to FIELD_GET() if you want to. > > > > Good point. You could use le16_get_bits() though which I'm fairly sure will take > > a variable just fine. > > > > I don't think it will work. > > From the commit log introducing the {type}_get_bits to <linux/bitfield.h> > " Field specification must be a constant; __builtin_constant_p() doesn't > have to be true for it, but compiler must be able to evaluate it at > build time. If it cannot or if the value does not encode any bitfield, > the build will fail. " > > Actually Geert Uytterhoeven tried to solve excatly this issue, but it > seems that the patch was not accepted. > Check: https://lore.kernel.org/linux-iio/3a54a6703879d10f08cf0275a2a69297ebd2b1d4.1637592133.git.geert+renesas@xxxxxxxxx/ > > > So which solution would be the best: > > 1. Use directly KX132_MASK_BUF_SMP_LVL, the only reason I was trying to > avoid this was to make this function generic enough for other chip > variants > > 2. Copy the field_get() definition from drivers/clk/at91 or from the commit > of Geert and use it in this driver > > 3. leave it as it is ? This fine. Sorry for the diversion to nowhere! Jonathan > > 4. another solution ? > > > > > > > > > > > > > > > > > + > > > > > + return fifo_bytes; > > > > > +} > > > > > + > > > > > static int __kx022a_fifo_flush(struct iio_dev *idev, unsigned int samples, > > > > > bool irq) > > > > > { > > > > > @@ -1036,6 +1157,32 @@ const struct kx022a_chip_info kx022a_chip_info = { > > > > > }; > > > > > EXPORT_SYMBOL_NS_GPL(kx022a_chip_info, IIO_KX022A); > > > > > > > > > > +const struct kx022a_chip_info kx132_chip_info = { > > > > > + .name = "kx132-1211", > > > > > + .regmap_config = &kx132_regmap_config, > > > > > + .channels = kx132_channels, > > > > > + .num_channels = ARRAY_SIZE(kx132_channels), > > > > > + .fifo_length = KX132_FIFO_LENGTH, > > > > > + .who = KX132_REG_WHO, > > > > > + .id = KX132_ID, > > > > > + .cntl = KX132_REG_CNTL, > > > > > + .cntl2 = KX132_REG_CNTL2, > > > > > + .odcntl = KX132_REG_ODCNTL, > > > > > + .buf_cntl1 = KX132_REG_BUF_CNTL1, > > > > > + .buf_cntl2 = KX132_REG_BUF_CNTL2, > > > > > + .buf_clear = KX132_REG_BUF_CLEAR, > > > > > + .buf_status1 = KX132_REG_BUF_STATUS_1, > > > > > + .buf_smp_lvl_mask = KX132_MASK_BUF_SMP_LVL, > > > > > > > > There are some things in here (typically where the define isn't used > > > > anywhere else) where I think it would be easier to follow if the > > > > value was listed here. Masks and IDs for example. > > > > > > > > > > After removing buf_smp_lvl_mask, which members will be easier to understand (besides id) ? > > > > I haven't gone through them. Length seems an obvious one. It's a number not a magic value. > > Register addresses might also be simpler if they aren't used elsewhere. > > > > Not really about understanding just about a define that adds nothing if all we do is > > assign it to a variable of the same name. > > Do you have a strong opinion about this ? > > I would really prefer to leave it like this, for the following reasons: > > 1. If I directly use values here, I have to do it also in the previous > patch where I introduce the chip_info for the kx022a -> this means I > will have defines in the h file which are not used at all -> the defines should > be deleted -> the patch will get unnecessarily bigger. I received > multiple comments about removing unnecessary changes and reducing of the > patch size when possible. > > 2. Consistency: having all the defines in one place really seems to be > better for understanding IMO. I find the mix of values and defines in > the chip-info a bit confusing, e.g., I will use the direct value for > KX132_REG_CNTL but not for KX132_REG_CNTL2 because KX132_REG_CNTL2 is > referenced in a regmap_range. > > -- > Kind Regards > Mehdi Djait
