[07/12] i2c: rk3x: account for const type of of_device_id.data

Message ID 1514899688-27844-8-git-send-email-Julia.Lawall@lip6.fr
State Accepted
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Series
  • account for const type of of_device_id.data
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Commit Message

Julia Lawall Jan. 2, 2018, 1:28 p.m.
This driver creates a number of const structures that it stores in
the data field of an of_device_id array.

The data field of an of_device_id structure has type const void *, so
there is no need for a const-discarding cast when putting const values
into such a structure.

Furthermore, adding const to the declaration of the location that
receives a const value from such a field ensures that the compiler
will continue to check that the value is not modified.  The
const-discarding cast on the extraction from the data field is thus
no longer needed.

Done using Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/i2c/busses/i2c-rk3x.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Comments

Wolfram Sang Jan. 15, 2018, 6:24 p.m. | #1
On Tue, Jan 02, 2018 at 02:28:03PM +0100, Julia Lawall wrote:
> This driver creates a number of const structures that it stores in
> the data field of an of_device_id array.
> 
> The data field of an of_device_id structure has type const void *, so
> there is no need for a const-discarding cast when putting const values
> into such a structure.
> 
> Furthermore, adding const to the declaration of the location that
> receives a const value from such a field ensures that the compiler
> will continue to check that the value is not modified.  The
> const-discarding cast on the extraction from the data field is thus
> no longer needed.
> 
> Done using Coccinelle.
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Heiko, you okay with the patch?

> 
> ---
>  drivers/i2c/busses/i2c-rk3x.c |   16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff -u -p a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
> --- a/drivers/i2c/busses/i2c-rk3x.c
> +++ b/drivers/i2c/busses/i2c-rk3x.c
> @@ -194,7 +194,7 @@ struct rk3x_i2c_soc_data {
>  struct rk3x_i2c {
>  	struct i2c_adapter adap;
>  	struct device *dev;
> -	struct rk3x_i2c_soc_data *soc_data;
> +	const struct rk3x_i2c_soc_data *soc_data;
>  
>  	/* Hardware resources */
>  	void __iomem *regs;
> @@ -1164,27 +1164,27 @@ static const struct rk3x_i2c_soc_data rk
>  static const struct of_device_id rk3x_i2c_match[] = {
>  	{
>  		.compatible = "rockchip,rv1108-i2c",
> -		.data = (void *)&rv1108_soc_data
> +		.data = &rv1108_soc_data
>  	},
>  	{
>  		.compatible = "rockchip,rk3066-i2c",
> -		.data = (void *)&rk3066_soc_data
> +		.data = &rk3066_soc_data
>  	},
>  	{
>  		.compatible = "rockchip,rk3188-i2c",
> -		.data = (void *)&rk3188_soc_data
> +		.data = &rk3188_soc_data
>  	},
>  	{
>  		.compatible = "rockchip,rk3228-i2c",
> -		.data = (void *)&rk3228_soc_data
> +		.data = &rk3228_soc_data
>  	},
>  	{
>  		.compatible = "rockchip,rk3288-i2c",
> -		.data = (void *)&rk3288_soc_data
> +		.data = &rk3288_soc_data
>  	},
>  	{
>  		.compatible = "rockchip,rk3399-i2c",
> -		.data = (void *)&rk3399_soc_data
> +		.data = &rk3399_soc_data
>  	},
>  	{},
>  };
> @@ -1207,7 +1207,7 @@ static int rk3x_i2c_probe(struct platfor
>  		return -ENOMEM;
>  
>  	match = of_match_node(rk3x_i2c_match, np);
> -	i2c->soc_data = (struct rk3x_i2c_soc_data *)match->data;
> +	i2c->soc_data = match->data;
>  
>  	/* use common interface to get I2C timing properties */
>  	i2c_parse_fw_timings(&pdev->dev, &i2c->t, true);
>
Heiko Stübner Jan. 17, 2018, 11 a.m. | #2
Am Montag, 15. Januar 2018, 19:24:56 CET schrieb Wolfram Sang:
> On Tue, Jan 02, 2018 at 02:28:03PM +0100, Julia Lawall wrote:
> > This driver creates a number of const structures that it stores in
> > the data field of an of_device_id array.
> > 
> > The data field of an of_device_id structure has type const void *, so
> > there is no need for a const-discarding cast when putting const values
> > into such a structure.
> > 
> > Furthermore, adding const to the declaration of the location that
> > receives a const value from such a field ensures that the compiler
> > will continue to check that the value is not modified.  The
> > const-discarding cast on the extraction from the data field is thus
> > no longer needed.
> > 
> > Done using Coccinelle.
> > 
> > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> Heiko, you okay with the patch?

Looks good to me and does not seem to contain any changes related
to actual functionality, so
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Wolfram Sang Jan. 17, 2018, 11:12 p.m. | #3
On Tue, Jan 02, 2018 at 02:28:03PM +0100, Julia Lawall wrote:
> This driver creates a number of const structures that it stores in
> the data field of an of_device_id array.
> 
> The data field of an of_device_id structure has type const void *, so
> there is no need for a const-discarding cast when putting const values
> into such a structure.
> 
> Furthermore, adding const to the declaration of the location that
> receives a const value from such a field ensures that the compiler
> will continue to check that the value is not modified.  The
> const-discarding cast on the extraction from the data field is thus
> no longer needed.
> 
> Done using Coccinelle.
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> 

Applied to for-next, thanks!

Patch

diff -u -p a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -194,7 +194,7 @@  struct rk3x_i2c_soc_data {
 struct rk3x_i2c {
 	struct i2c_adapter adap;
 	struct device *dev;
-	struct rk3x_i2c_soc_data *soc_data;
+	const struct rk3x_i2c_soc_data *soc_data;
 
 	/* Hardware resources */
 	void __iomem *regs;
@@ -1164,27 +1164,27 @@  static const struct rk3x_i2c_soc_data rk
 static const struct of_device_id rk3x_i2c_match[] = {
 	{
 		.compatible = "rockchip,rv1108-i2c",
-		.data = (void *)&rv1108_soc_data
+		.data = &rv1108_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3066-i2c",
-		.data = (void *)&rk3066_soc_data
+		.data = &rk3066_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3188-i2c",
-		.data = (void *)&rk3188_soc_data
+		.data = &rk3188_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3228-i2c",
-		.data = (void *)&rk3228_soc_data
+		.data = &rk3228_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3288-i2c",
-		.data = (void *)&rk3288_soc_data
+		.data = &rk3288_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3399-i2c",
-		.data = (void *)&rk3399_soc_data
+		.data = &rk3399_soc_data
 	},
 	{},
 };
@@ -1207,7 +1207,7 @@  static int rk3x_i2c_probe(struct platfor
 		return -ENOMEM;
 
 	match = of_match_node(rk3x_i2c_match, np);
-	i2c->soc_data = (struct rk3x_i2c_soc_data *)match->data;
+	i2c->soc_data = match->data;
 
 	/* use common interface to get I2C timing properties */
 	i2c_parse_fw_timings(&pdev->dev, &i2c->t, true);