Re: [PATCH 12/13] drivers/media/tuners/max2165.c: use macros for i2c_msg initialization

Ryan Mallon
2012-10-07T22:14:31Z

On 08/10/12 02:38, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@lip6.fr>
>
> Introduce use of I2c_MSG_READ/WRITE/OP, for readability.
>
> A length expressed as an explicit constant is also re-expressed as the size
> of the buffer, when this is possible.
>
> The second case is simplified to use simple variables rather than arrays.
> The variable b0 is dropped completely, and the variable reg that it
> contains is used instead. The variable b1 is replaced by a u8-typed
> variable named buf (the name used earlier in the file). The uses of b1 are
> then adjusted accordingly.
>
> 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@lip6.fr>
>
> ---
>
> drivers/media/tuners/max2165.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/tuners/max2165.c b/drivers/media/tuners/max2165.c
> index ba84936..6638617 100644
> --- a/drivers/media/tuners/max2165.c
> +++ b/drivers/media/tuners/max2165.c
> @@ -47,7 +47,7 @@ static int max2165_write_reg(struct max2165_priv *priv, u8 reg, u8 data)
> {
> int ret;
> u8 buf[] = { reg, data };
> - struct i2c_msg msg = { .flags = 0, .buf = buf, .len = 2 };
> + struct i2c_msg msg = I2C_MSG_WRITE(0, buf, sizeof(buf));
>
> msg.addr = priv->config->i2c_address;
>
> @@ -68,11 +68,10 @@ static int max2165_read_reg(struct max2165_priv *priv, u8 reg, u8 *p_data)
> int ret;
> u8 dev_addr = priv->config->i2c_address;
>
> - u8 b0[] = { reg };
> - u8 b1[] = { 0 };
> + u8 buf;
> struct i2c_msg msg[] = {
> - { .addr = dev_addr, .flags = 0, .buf = b0, .len = 1 },
> - { .addr = dev_addr, .flags = I2C_M_RD, .buf = b1, .len = 1 },
> + I2C_MSG_WRITE(dev_addr, &reg, sizeof(reg)),
> + I2C_MSG_READ(dev_addr, &buf, sizeof(buf)),
> };

Not sure if the array changes should be done here or as a separate
patch. Some of the other patches also have cases where single index
arrays (both buffers and messages) could be converted. Should either
convert all or none of them. I think its probably best to do as a
separate series on top of this though.

~Ryan

>
> ret = i2c_transfer(priv->i2c, msg, 2);
> @@ -81,10 +80,10 @@ static int max2165_read_reg(struct max2165_priv *priv, u8 reg, u8 *p_data)
> return -EIO;
> }
>
> - *p_data = b1[0];
> + *p_data = buf;
> if (debug >= 2)
> dprintk("%s: reg=0x%02X, data=0x%02X\n",
> - __func__, reg, b1[0]);
> + __func__, reg, buf);
> return 0;
> }
>
>