diff mbox series

[v2,5/6] pwm: lpss: Add pwm_lpss_probe() stub

Message ID 20221108142226.63161-6-andriy.shevchenko@linux.intel.com
State New
Headers
Series pinctrl: intel: Enable PWM optional feature |

Commit Message

Andy Shevchenko Nov. 8, 2022, 2:22 p.m. UTC 
  In case the PWM LPSS module is not provided, allow users to be
compiled with a help of a pwm_lpss_probe() stub.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 include/linux/platform_data/x86/pwm-lpss.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Uwe Kleine-König Nov. 10, 2022, 7:38 a.m. UTC | #1 
On Tue, Nov 08, 2022 at 04:22:25PM +0200, Andy Shevchenko wrote:
> In case the PWM LPSS module is not provided, allow users to be
> compiled with a help of a pwm_lpss_probe() stub.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
>  include/linux/platform_data/x86/pwm-lpss.h | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/include/linux/platform_data/x86/pwm-lpss.h b/include/linux/platform_data/x86/pwm-lpss.h
> index 296bd837ddbb..c868b396ed2c 100644
> --- a/include/linux/platform_data/x86/pwm-lpss.h
> +++ b/include/linux/platform_data/x86/pwm-lpss.h
> @@ -4,6 +4,8 @@
>  #ifndef __PLATFORM_DATA_X86_PWM_LPSS_H
>  #define __PLATFORM_DATA_X86_PWM_LPSS_H
>  
> +#include <linux/err.h>
> +#include <linux/kconfig.h>
>  #include <linux/types.h>
>  
>  struct device;
> @@ -27,7 +29,16 @@ struct pwm_lpss_boardinfo {
>  	bool other_devices_aml_touches_pwm_regs;
>  };
>  
> +#if IS_REACHABLE(CONFIG_PWM_LPSS)
>  struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
>  				     const struct pwm_lpss_boardinfo *info);
> +#else
> +static inline
> +struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
> +				     const struct pwm_lpss_boardinfo *info)
> +{
> +	return ERR_PTR(-ENODEV);

Would it be more consistent to return the same value as the pwmchip_add
stub does?

Best regards
Uwe
Andy Shevchenko Nov. 10, 2022, 10:01 a.m. UTC | #2 
On Thu, Nov 10, 2022 at 9:38 AM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
> On Tue, Nov 08, 2022 at 04:22:25PM +0200, Andy Shevchenko wrote:
> > In case the PWM LPSS module is not provided, allow users to be
> > compiled with a help of a pwm_lpss_probe() stub.

...

> > +static inline
> > +struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
> > +                                  const struct pwm_lpss_boardinfo *info)
> > +{
> > +     return ERR_PTR(-ENODEV);
>
> Would it be more consistent to return the same value as the pwmchip_add
> stub does?

Then I will lose the ability to distinguish between absent driver (or
device) and actual error during the probing of it. Any suggestions on
how to do that better?
Andy Shevchenko Nov. 11, 2022, 1:57 p.m. UTC | #3 
On Thu, Nov 10, 2022 at 12:01:50PM +0200, Andy Shevchenko wrote:
> On Thu, Nov 10, 2022 at 9:38 AM Uwe Kleine-König
> <u.kleine-koenig@pengutronix.de> wrote:
> > On Tue, Nov 08, 2022 at 04:22:25PM +0200, Andy Shevchenko wrote:
> > > In case the PWM LPSS module is not provided, allow users to be
> > > compiled with a help of a pwm_lpss_probe() stub.

...

> > > +static inline
> > > +struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
> > > +                                  const struct pwm_lpss_boardinfo *info)
> > > +{
> > > +     return ERR_PTR(-ENODEV);
> >
> > Would it be more consistent to return the same value as the pwmchip_add
> > stub does?
> 
> Then I will lose the ability to distinguish between absent driver (or
> device) and actual error during the probing of it. Any suggestions on
> how to do that better?

Independently on the above, I think that _probe() != _chip_add() semantically
and having the same, and we know weird, return code doesn't make it anyhow
better. I believe that -ENODEV is the best fit here.

That said, I leave it as is for v3 and we may continue discussing it there.
diff mbox series

Patch

diff --git a/include/linux/platform_data/x86/pwm-lpss.h b/include/linux/platform_data/x86/pwm-lpss.h
index 296bd837ddbb..c868b396ed2c 100644
--- a/include/linux/platform_data/x86/pwm-lpss.h
+++ b/include/linux/platform_data/x86/pwm-lpss.h
@@ -4,6 +4,8 @@ 
 #ifndef __PLATFORM_DATA_X86_PWM_LPSS_H
 #define __PLATFORM_DATA_X86_PWM_LPSS_H
 
+#include <linux/err.h>
+#include <linux/kconfig.h>
 #include <linux/types.h>
 
 struct device;
@@ -27,7 +29,16 @@  struct pwm_lpss_boardinfo {
 	bool other_devices_aml_touches_pwm_regs;
 };
 
+#if IS_REACHABLE(CONFIG_PWM_LPSS)
 struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
 				     const struct pwm_lpss_boardinfo *info);
+#else
+static inline
+struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, void __iomem *base,
+				     const struct pwm_lpss_boardinfo *info)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif	/* CONFIG_PWM_LPSS */
 
 #endif	/* __PLATFORM_DATA_X86_PWM_LPSS_H */