linux-kernel - Re: [PATCH 1/2] serial: mctrl_gpio: add a new API to enable / disable wake

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Date:   Fri, 4 Feb 2022 16:41:58 +0100
From:   Erwan LE RAY <erwan.leray@...s.st.com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
CC:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        Gerald Baeza <gerald.baeza@...com>,
        Valentin Caron <valentin.caron@...s.st.com>,
        "linux-serial@...r.kernel.org" <linux-serial@...r.kernel.org>,
        "linux-stm32@...md-mailman.stormreply.com" 
        <linux-stm32@...md-mailman.stormreply.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] serial: mctrl_gpio: add a new API to enable / disable
 wake_irq

Hi Andy,

On 2/4/22 10:07 AM, Andy Shevchenko wrote:
> 
> 
> On Thursday, February 3, 2022, Erwan Le Ray <erwan.leray@...s.st.com 
> <mailto:erwan.leray@...s.st.com>> wrote:
> 
>     Add a new API to enable / disable wake_irq in order to enable gpio
>     irqs as
>     wakeup irqs for the uart port.
> 
>     Signed-off-by: Erwan Le Ray <erwan.leray@...s.st.com
>     <mailto:erwan.leray@...s.st.com>>
> 
>     diff --git a/drivers/tty/serial/serial_mctrl_gpio.c
>     b/drivers/tty/serial/serial_mctrl_gpio.c
>     index c41d8911ce95..1663b3afc3a0 100644
>     --- a/drivers/tty/serial/serial_mctrl_gpio.c
>     +++ b/drivers/tty/serial/serial_mctrl_gpio.c
>     @@ -299,4 +299,42 @@ void mctrl_gpio_disable_ms(struct mctrl_gpios
>     *gpios)
>       }
>       EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
> 
>     +void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
>     +{
>     +       enum mctrl_gpio_idx i;
>     +
>     +       if (!gpios)
>     +               return;
>     +
>     +       if (!gpios->mctrl_on)
>     +               return;
>     +
>     +       for (i = 0; i < UART_GPIO_MAX; ++i) {
>     +               if (!gpios->irq[i])
>     +                       continue;
> 
> 
> 
> Why not simply
> 
>    if (gpios[])
>      enable_irq_...
> 
> ?
> 
> And same for disabling.
> 
>     +
>     +               enable_irq_wake(gpios->irq[i]);
>     +       }
>     +}
>     +EXPORT_SYMBOL_GPL(mctrl_gpio_enable_irq_wake);
>     +
>     +void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios)
>     +{
>     +       enum mctrl_gpio_idx i;
>     +
>     +       if (!gpios)
>     +               return;
>     +
>     +       if (!gpios->mctrl_on)
>     +               return;
>     +
>     +       for (i = 0; i < UART_GPIO_MAX; ++i) {
>     +               if (!gpios->irq[i])
>     +                       continue;
>     +
>     +               disable_irq_wake(gpios->irq[i]);
>     +       }
>     +}
>     +EXPORT_SYMBOL_GPL(mctrl_gpio_disable_irq_wake);
>     +
>       MODULE_LICENSE("GPL");
>     diff --git a/drivers/tty/serial/serial_mctrl_gpio.h
>     b/drivers/tty/serial/serial_mctrl_gpio.h
>     index b134a0ffc894..fc76910fb105 100644
>     --- a/drivers/tty/serial/serial_mctrl_gpio.h
>     +++ b/drivers/tty/serial/serial_mctrl_gpio.h
>     @@ -91,6 +91,16 @@ void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
>        */
>       void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
> 
>     +/*
>     + * Enable gpio wakeup interrupts to enable wake up source.
>     + */
>     +void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios);
>     +
>     +/*
>     + * Disable gpio wakeup interrupts to enable wake up source.
>     + */
>     +void mctrl_gpio_disable_irq_wake(struct mctrl_gpios *gpios);
>     +
>       #else /* GPIOLIB */
> 
>       static inline
>     @@ -142,6 +152,14 @@ static inline void mctrl_gpio_disable_ms(struct
>     mctrl_gpios *gpios)
>       {
>       }
> 
>     +static inline void mctrl_gpio_enable_irq_wake(struct mctrl_gpios
>     *gpios)
>     +{
>     +}
>     +
>     +static inline void mctrl_gpio_disable_irq_wake(struct mctrl_gpios
>     *gpios)
>     +{
>     +}
>     +
>       #endif /* GPIOLIB */
> 
>       #endif
>     -- 
>     2.17.1
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Thanks for your review.
I fully agree with your comment, but I wrote this code like it is to 
keep the same structure than all the other ops of serial_mcrtrl_gpio 
driver. I preferred keeping an homogeneous code in the driver rather 
than breaking the driver homogeneity with the addition of an optimized code.

Greg, can you please indicate which solution you recommend ?

Cheers, Erwan.