Hi Siddharth, Adding some comments inline. If what Jonathan suggested + what I suggest bellow is still insufficient to avoid those lots of shifting to make up a write command, then probably not worth it to change those as Jonathan said. On 03/14, Siddharth Menon wrote: > Refactor code to use the FIELD_PREP macro for setting bit fields > instead of manual bit manipulation. > > Suggested-by: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx> > Signed-off-by: Siddharth Menon <simeddon@xxxxxxxxx> > --- > drivers/staging/iio/frequency/ad9832.c | 39 ++++++++++++++------------ > 1 file changed, 21 insertions(+), 18 deletions(-) > > diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c > index 140ee4f9c137..bbde1f0e84ff 100644 > --- a/drivers/staging/iio/frequency/ad9832.c > +++ b/drivers/staging/iio/frequency/ad9832.c > @@ -70,6 +70,9 @@ > #define AD9832_FREQ_BITS 32 > #define AD9832_PHASE_BITS 12 > #define RES_MASK(bits) ((1 << (bits)) - 1) > +#define DATA_MASK 0xFF > +#define CMD_MASK (0xF << CMD_SHIFT) > +#define ADD_MASK (0xF << ADD_SHIFT) We could have masks for each part of the write command. For example, #define CMD_MASK GENMASK(15, 12) #define ADD_MASK GENMASK(11, 8) #define DATA_MASK GENMASK(7, 0) > > /** > * struct ad9832_state - driver instance specific data > @@ -139,18 +142,18 @@ static int ad9832_write_frequency(struct ad9832_state *st, > > regval = ad9832_calc_freqreg(clk_freq, fout); > > - st->freq_data[0] = cpu_to_be16((AD9832_CMD_FRE8BITSW << CMD_SHIFT) | > - (addr << ADD_SHIFT) | > - ((regval >> 24) & 0xFF)); > - st->freq_data[1] = cpu_to_be16((AD9832_CMD_FRE16BITSW << CMD_SHIFT) | > - ((addr - 1) << ADD_SHIFT) | > - ((regval >> 16) & 0xFF)); > - st->freq_data[2] = cpu_to_be16((AD9832_CMD_FRE8BITSW << CMD_SHIFT) | > - ((addr - 2) << ADD_SHIFT) | > - ((regval >> 8) & 0xFF)); > - st->freq_data[3] = cpu_to_be16((AD9832_CMD_FRE16BITSW << CMD_SHIFT) | > - ((addr - 3) << ADD_SHIFT) | > - ((regval >> 0) & 0xFF)); > + st->freq_data[0] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE8BITSW) | > + FIELD_PREP(ADD_MASK, addr) | > + FIELD_PREP(DATA_MASK, (regval >> 24) & 0xFF)); Then we can use FIELD_PREP() in combination with the masks. Example, st->freq_data[0] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE8BITSW) | FIELD_PREP(ADD_MASK, addr) | FIELD_PREP(DATA_MASK, (regval >> 24)); > + st->freq_data[1] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE16BITSW) | > + FIELD_PREP(ADD_MASK, (addr - 1)) | > + FIELD_PREP(DATA_MASK, (regval >> 16) & 0xFF)); > + st->freq_data[2] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE8BITSW) | > + FIELD_PREP(ADD_MASK, (addr - 2)) | > + FIELD_PREP(DATA_MASK, (regval >> 8) & 0xFF)); > + st->freq_data[3] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE16BITSW) | > + FIELD_PREP(ADD_MASK, (addr - 3)) | > + FIELD_PREP(DATA_MASK, (regval >> 0) & 0xFF)); If able to make regval an array as Jonathan suggested, the above may become something like for (i = 0; i < ARRAY_SIZE(st->freq_data); i++) st->freq_data[i] = cpu_to_be16(FIELD_PREP(CMD_MASK, AD9832_CMD_FRE8BITSW) | FIELD_PREP(ADD_MASK, addr) | FIELD_PREP(DATA_MASK, (regval[i]))); Note the command alternates between AD9832_CMD_FRE8BITSW and AD9832_CMD_FRE16BITSW so maybe also put the command constants into an array or use some ternary operation like i % 2 == 0 ? AD9832_CMD_FRE8BITSW : AD9832_CMD_FRE16BITS.
