The whole struct/function declarations in this header are surrounded
by #ifdef.
As far as I understood, the motivation of this is probably to break
the build earlier if a driver misses to select or depend on correct
CONFIG options in Kconfig.
Since commit 94bed2a9c4ae ("Add -Werror-implicit-function-declaration")
no one cannot call functions that have not been declared.
So, I see some benefit in doing this in the cost of uglier headers.
In reality, it would not be so easy to catch missed 'select' or
'depends on' because GPIOLIB, GPIOLIB_IRQCHIP etc. are already selected
by someone else eventually. So, this kind of error, if any, will be
caught by randconfig bots.
In summary, I am not a big fan of cluttered #ifdef nesting, and this
does not matter for normal developers. The code readability wins.
Signed-off-by: Masahiro Yamada <[email protected]>
---
Changes in v2:
- rebase
include/linux/gpio/driver.h | 27 ++++++++-------------------
1 file changed, 8 insertions(+), 19 deletions(-)
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 6a0e420915a3..f28f534f451a 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -20,9 +20,6 @@ struct module;
enum gpiod_flags;
enum gpio_lookup_flags;
-#ifdef CONFIG_GPIOLIB
-
-#ifdef CONFIG_GPIOLIB_IRQCHIP
/**
* struct gpio_irq_chip - GPIO interrupt controller
*/
@@ -161,7 +158,6 @@ struct gpio_irq_chip {
*/
void (*irq_disable)(struct irq_data *data);
};
-#endif /* CONFIG_GPIOLIB_IRQCHIP */
/**
* struct gpio_chip - abstract a GPIO controller
@@ -441,16 +437,12 @@ bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
/* get driver data */
void *gpiochip_get_data(struct gpio_chip *chip);
-struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
-
struct bgpio_pdata {
const char *label;
int base;
int ngpio;
};
-#if IS_ENABLED(CONFIG_GPIO_GENERIC)
-
int bgpio_init(struct gpio_chip *gc, struct device *dev,
unsigned long sz, void __iomem *dat, void __iomem *set,
void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
@@ -463,10 +455,6 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
#define BGPIOF_READ_OUTPUT_REG_SET BIT(4) /* reg_set stores output value */
#define BGPIOF_NO_OUTPUT BIT(5) /* only input */
-#endif /* CONFIG_GPIO_GENERIC */
-
-#ifdef CONFIG_GPIOLIB_IRQCHIP
-
int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq);
void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
@@ -555,15 +543,11 @@ static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
}
#endif /* CONFIG_LOCKDEP */
-#endif /* CONFIG_GPIOLIB_IRQCHIP */
-
int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
unsigned long config);
-#ifdef CONFIG_PINCTRL
-
/**
* struct gpio_pin_range - pin range controlled by a gpio chip
* @node: list for maintaining set of pin ranges, used internally
@@ -576,6 +560,8 @@ struct gpio_pin_range {
struct pinctrl_gpio_range range;
};
+#ifdef CONFIG_PINCTRL
+
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins);
@@ -586,8 +572,6 @@ void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
#else /* ! CONFIG_PINCTRL */
-struct pinctrl_dev;
-
static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
@@ -619,6 +603,11 @@ void gpiochip_free_own_desc(struct gpio_desc *desc);
void devprop_gpiochip_set_names(struct gpio_chip *chip,
const struct fwnode_handle *fwnode);
+
+#ifdef CONFIG_GPIOLIB
+
+struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
+
#else /* CONFIG_GPIOLIB */
static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
@@ -630,4 +619,4 @@ static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
#endif /* CONFIG_GPIOLIB */
-#endif
+#endif /* __LINUX_GPIO_DRIVER_H */
--
2.17.1
wt., 30 lip 2019 o 07:44 Masahiro Yamada
<[email protected]> napisał(a):
>
> The whole struct/function declarations in this header are surrounded
> by #ifdef.
>
> As far as I understood, the motivation of this is probably to break
> the build earlier if a driver misses to select or depend on correct
> CONFIG options in Kconfig.
>
> Since commit 94bed2a9c4ae ("Add -Werror-implicit-function-declaration")
> no one cannot call functions that have not been declared.
>
> So, I see some benefit in doing this in the cost of uglier headers.
>
> In reality, it would not be so easy to catch missed 'select' or
> 'depends on' because GPIOLIB, GPIOLIB_IRQCHIP etc. are already selected
> by someone else eventually. So, this kind of error, if any, will be
> caught by randconfig bots.
>
> In summary, I am not a big fan of cluttered #ifdef nesting, and this
> does not matter for normal developers. The code readability wins.
>
> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> Changes in v2:
> - rebase
>
> include/linux/gpio/driver.h | 27 ++++++++-------------------
> 1 file changed, 8 insertions(+), 19 deletions(-)
>
> diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
> index 6a0e420915a3..f28f534f451a 100644
> --- a/include/linux/gpio/driver.h
> +++ b/include/linux/gpio/driver.h
> @@ -20,9 +20,6 @@ struct module;
> enum gpiod_flags;
> enum gpio_lookup_flags;
>
> -#ifdef CONFIG_GPIOLIB
> -
> -#ifdef CONFIG_GPIOLIB_IRQCHIP
> /**
> * struct gpio_irq_chip - GPIO interrupt controller
> */
> @@ -161,7 +158,6 @@ struct gpio_irq_chip {
> */
> void (*irq_disable)(struct irq_data *data);
> };
> -#endif /* CONFIG_GPIOLIB_IRQCHIP */
>
> /**
> * struct gpio_chip - abstract a GPIO controller
> @@ -441,16 +437,12 @@ bool gpiochip_line_is_valid(const struct gpio_chip *chip, unsigned int offset);
> /* get driver data */
> void *gpiochip_get_data(struct gpio_chip *chip);
>
> -struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
> -
> struct bgpio_pdata {
> const char *label;
> int base;
> int ngpio;
> };
>
> -#if IS_ENABLED(CONFIG_GPIO_GENERIC)
> -
> int bgpio_init(struct gpio_chip *gc, struct device *dev,
> unsigned long sz, void __iomem *dat, void __iomem *set,
> void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
> @@ -463,10 +455,6 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
> #define BGPIOF_READ_OUTPUT_REG_SET BIT(4) /* reg_set stores output value */
> #define BGPIOF_NO_OUTPUT BIT(5) /* only input */
>
> -#endif /* CONFIG_GPIO_GENERIC */
> -
> -#ifdef CONFIG_GPIOLIB_IRQCHIP
> -
> int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
> irq_hw_number_t hwirq);
> void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq);
> @@ -555,15 +543,11 @@ static inline int gpiochip_irqchip_add_nested(struct gpio_chip *gpiochip,
> }
> #endif /* CONFIG_LOCKDEP */
>
> -#endif /* CONFIG_GPIOLIB_IRQCHIP */
> -
> int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset);
> void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset);
> int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
> unsigned long config);
>
> -#ifdef CONFIG_PINCTRL
> -
> /**
> * struct gpio_pin_range - pin range controlled by a gpio chip
> * @node: list for maintaining set of pin ranges, used internally
> @@ -576,6 +560,8 @@ struct gpio_pin_range {
> struct pinctrl_gpio_range range;
> };
>
> +#ifdef CONFIG_PINCTRL
> +
> int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
> unsigned int gpio_offset, unsigned int pin_offset,
> unsigned int npins);
> @@ -586,8 +572,6 @@ void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
>
> #else /* ! CONFIG_PINCTRL */
>
> -struct pinctrl_dev;
> -
> static inline int
> gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
> unsigned int gpio_offset, unsigned int pin_offset,
> @@ -619,6 +603,11 @@ void gpiochip_free_own_desc(struct gpio_desc *desc);
> void devprop_gpiochip_set_names(struct gpio_chip *chip,
> const struct fwnode_handle *fwnode);
>
> +
> +#ifdef CONFIG_GPIOLIB
> +
> +struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
> +
> #else /* CONFIG_GPIOLIB */
>
> static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> @@ -630,4 +619,4 @@ static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
>
> #endif /* CONFIG_GPIOLIB */
>
> -#endif
> +#endif /* __LINUX_GPIO_DRIVER_H */
> --
> 2.17.1
>
Patch applied, thanks!
Bartosz