Re: [PATCH 13/13] drivers/media/tuners/e4000.c: use macros fori2c_msg initialization

[Julia Lawall]

On Sun, 7 Oct 2012, walter harms wrote:

> Am 07.10.2012 17:38, schrieb Julia Lawall:
> > From: Julia Lawall <Julia.Lawall@xxxxxxx>
> >
> > Introduce use of I2c_MSG_READ/WRITE/OP, for readability.
> >
> > In the second i2c_msg structure, a length expressed as an explicit constant
> > is also re-expressed as the size of the buffer, reg.
> >
> > A simplified version of the semantic patch that makes this change is as
> > follows: (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @@
> > expression a,b,c;
> > identifier x;
> > @@
> >
> > struct i2c_msg x =
> > - {.addr = a, .buf = b, .len = c, .flags = I2C_M_RD}
> > + I2C_MSG_READ(a,b,c)
> >  ;
> >
> > @@
> > expression a,b,c;
> > identifier x;
> > @@
> >
> > struct i2c_msg x =
> > - {.addr = a, .buf = b, .len = c, .flags = 0}
> > + I2C_MSG_WRITE(a,b,c)
> >  ;
> >
> > @@
> > expression a,b,c,d;
> > identifier x;
> > @@
> >
> > struct i2c_msg x =
> > - {.addr = a, .buf = b, .len = c, .flags = d}
> > + I2C_MSG_OP(a,b,c,d)
> >  ;
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>
> >
> > ---
> >  drivers/media/tuners/e4000.c |   20 +++-----------------
> >  1 file changed, 3 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/media/tuners/e4000.c b/drivers/media/tuners/e4000.c
> > index 1b33ed3..8f182fc 100644
> > --- a/drivers/media/tuners/e4000.c
> > +++ b/drivers/media/tuners/e4000.c
> > @@ -26,12 +26,7 @@ static int e4000_wr_regs(struct e4000_priv *priv, u8 reg, u8 *val, int len)
> >  	int ret;
> >  	u8 buf[1 + len];
> >  	struct i2c_msg msg[1] = {
> > -		{
> > -			.addr = priv->cfg->i2c_addr,
> > -			.flags = 0,
> > -			.len = sizeof(buf),
> > -			.buf = buf,
> > -		}
> > +		I2C_MSG_WRITE(priv->cfg->i2c_addr, buf, sizeof(buf))
> >  	};
>
> Any reason why struct i2c_msg is an array ?

I assumed that it looked more harmonious with the other uses of 
i2c_transfer, which takes as arguments an array and the number of 
elements.

But there are some files that instead use i2c_transfer(priv->i2c, &msg, 1).
I can change them all to do that if that is preferred.  But maybe I 
will wait a little bit to see if there are other issues to address at 
the same time.

thanks,
julia

> re,
> wh
>
> >  	buf[0] = reg;
> > @@ -54,17 +49,8 @@ static int e4000_rd_regs(struct e4000_priv *priv, u8 reg, u8 *val, int len)
> >  	int ret;
> >  	u8 buf[len];
> >  	struct i2c_msg msg[2] = {
> > -		{
> > -			.addr = priv->cfg->i2c_addr,
> > -			.flags = 0,
> > -			.len = 1,
> > -			.buf = &reg,
> > -		}, {
> > -			.addr = priv->cfg->i2c_addr,
> > -			.flags = I2C_M_RD,
> > -			.len = sizeof(buf),
> > -			.buf = buf,
> > -		}
> > +		I2C_MSG_WRITE(priv->cfg->i2c_addr, &reg, sizeof(reg)),
> > +		I2C_MSG_READ(priv->cfg->i2c_addr, buf, sizeof(buf))
> >  	};
> >
> >  	ret = i2c_transfer(priv->i2c, msg, 2);
> >
> > --
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