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

Julia Lawall
2012-10-07T15:39:27Z

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)),
};

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;
}