Re: [PATCH 5/6] Staging: iio: impedance-analyzer: Prefer using the BIT macro

[Julia Lawall]

On Thu, 10 Sep 2015, Shraddha Barke wrote:

>
>
> On Thu, 10 Sep 2015, Julia Lawall wrote:
>
> > On Thu, 10 Sep 2015, Shraddha Barke wrote:
> >
> > > This patch replaces bit shifting on 1 with the BIT(x) macro
> > > as it's extensively used by other function in this driver.
> > >
> > > This was done with coccinelle:
> > > @@ int g; @@
> > >
> > > -(1 << g)
> > > +BIT(g)
> >
> > This doesn't look like a good idea here, since there is a mixture of uses
> > of BIT and other things for similar values.
> >
> Yes I'll send a new patch series dropping the cases of mixed uses of BIT.
> I hope Greg will ignore these patches.
> I found some instances of this issue in lustre file system.Should I go
> ahead with fixing those too?

That could be fine.

julia

>
> Thanks,
>
> Shraddha
>
>
> > julia
> >
> > > Signed-off-by: Shraddha Barke <shraddha.6596@xxxxxxxxx>
> > > ---
> > >  drivers/staging/iio/impedance-analyzer/ad5933.c | 22
> > > +++++++++++-----------
> > >  1 file changed, 11 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c
> > > b/drivers/staging/iio/impedance-analyzer/ad5933.c
> > > index c18109c..48acad0 100644
> > > --- a/drivers/staging/iio/impedance-analyzer/ad5933.c
> > > +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
> > > @@ -39,7 +39,7 @@
> > >  #define AD5933_REG_IMAG_DATA		0x96	/* R, 2 bytes*/
> > >
> > >  /* AD5933_REG_CONTROL_HB Bits */
> > > -#define AD5933_CTRL_INIT_START_FREQ	(0x1 << 4)
> > > +#define AD5933_CTRL_INIT_START_FREQ	BIT(4)
> > >  #define AD5933_CTRL_START_SWEEP		(0x2 << 4)
> > >  #define AD5933_CTRL_INC_FREQ		(0x3 << 4)
> > >  #define AD5933_CTRL_REPEAT_FREQ		(0x4 << 4)
> > > @@ -48,23 +48,23 @@
> > >  #define AD5933_CTRL_STANDBY		(0xB << 4)
> > >
> > >  #define AD5933_CTRL_RANGE_2000mVpp	(0x0 << 1)
> > > -#define AD5933_CTRL_RANGE_200mVpp	(0x1 << 1)
> > > +#define AD5933_CTRL_RANGE_200mVpp	BIT(1)
> > >  #define AD5933_CTRL_RANGE_400mVpp	(0x2 << 1)
> > >  #define AD5933_CTRL_RANGE_1000mVpp	(0x3 << 1)
> > >  #define AD5933_CTRL_RANGE(x)		((x) << 1)
> > >
> > > -#define AD5933_CTRL_PGA_GAIN_1		(0x1 << 0)
> > > +#define AD5933_CTRL_PGA_GAIN_1		BIT(0)
> > >  #define AD5933_CTRL_PGA_GAIN_5		(0x0 << 0)
> > >
> > >  /* AD5933_REG_CONTROL_LB Bits */
> > > -#define AD5933_CTRL_RESET		(0x1 << 4)
> > > +#define AD5933_CTRL_RESET		BIT(4)
> > >  #define AD5933_CTRL_INT_SYSCLK		(0x0 << 3)
> > > -#define AD5933_CTRL_EXT_SYSCLK		(0x1 << 3)
> > > +#define AD5933_CTRL_EXT_SYSCLK		BIT(3)
> > >
> > >  /* AD5933_REG_STATUS Bits */
> > > -#define AD5933_STAT_TEMP_VALID		(0x1 << 0)
> > > -#define AD5933_STAT_DATA_VALID		(0x1 << 1)
> > > -#define AD5933_STAT_SWEEP_DONE		(0x1 << 2)
> > > +#define AD5933_STAT_TEMP_VALID		BIT(0)
> > > +#define AD5933_STAT_DATA_VALID		BIT(1)
> > > +#define AD5933_STAT_SWEEP_DONE		BIT(2)
> > >
> > >  /* I2C Block Commands */
> > >  #define AD5933_I2C_BLOCK_WRITE		0xA0
> > > @@ -222,7 +222,7 @@ static int ad5933_set_freq(struct ad5933_state *st,
> > >  		u8 d8[4];
> > >  	} dat;
> > >
> > > -	freqreg = (u64) freq * (u64) (1 << 27);
> > > +	freqreg = (u64) freq * (u64) BIT(27);
> > >  	do_div(freqreg, st->mclk_hz / 4);
> > >
> > >  	switch (reg) {
> > > @@ -308,7 +308,7 @@ static ssize_t ad5933_show_frequency(struct device
> > > *dev,
> > >  	freqreg = be32_to_cpu(dat.d32) & 0xFFFFFF;
> > >
> > >  	freqreg = (u64) freqreg * (u64) (st->mclk_hz / 4);
> > > -	do_div(freqreg, 1 << 27);
> > > +	do_div(freqreg, BIT(27));
> > >
> > >  	return sprintf(buf, "%d\n", (int) freqreg);
> > >  }
> > > @@ -437,7 +437,7 @@ static ssize_t ad5933_store(struct device *dev,
> > >
> > >  		/* 2x, 4x handling, see datasheet */
> > >  		if (val > 511)
> > > -			val = (val >> 1) | (1 << 9);
> > > +			val = (val >> 1) | BIT(9);
> > >  		else if (val > 1022)
> > >  			val = (val >> 2) | (3 << 9);
> > >
> > > --
> > > 2.1.4
> > >
> > >
> >
>
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