[PATCH v2] gpio: dwapb: Add support for a bus clock

[PATCH v2] gpio: dwapb: Add support for a bus clock

[Phil Edworthy]

Enable an optional bus clock provided by DT.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
---
v2:
 - Fix include order.
 - Use a clock name.
 - Check errors from clk_prepare_enable()
 - Add calls to enable/disable the clock in PM
---
 drivers/gpio/gpio-dwapb.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index b0704a8..226977f 100644
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -8,8 +8,9 @@
  * All enquiries to support@picochip.com
  */
 #include <linux/acpi.h>
-#include <linux/gpio/driver.h>
+#include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/gpio/driver.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -98,6 +99,7 @@ struct dwapb_gpio {
 	struct irq_domain	*domain;
 	unsigned int		flags;
 	struct reset_control	*rst;
+	struct clk		*clk;
 };
 
 static inline u32 gpio_reg_v2_convert(unsigned int offset)
@@ -670,6 +672,16 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(gpio->regs))
 		return PTR_ERR(gpio->regs);
 
+	/* Optional bus clock */
+	gpio->clk = devm_clk_get(&pdev->dev, "bus");
+	if (!IS_ERR(gpio->clk)) {
+		err = clk_prepare_enable(gpio->clk);
+		if (err) {
+			dev_info(&pdev->dev, "Cannot enable clock\n");
+			return err;
+		}
+	}
+
 	gpio->flags = 0;
 	if (dev->of_node) {
 		const struct of_device_id *of_devid;
@@ -712,6 +724,7 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
 	dwapb_gpio_unregister(gpio);
 	dwapb_irq_teardown(gpio);
 	reset_control_assert(gpio->rst);
+	clk_disable_unprepare(gpio->clk);
 
 	return 0;
 }
@@ -757,6 +770,8 @@ static int dwapb_gpio_suspend(struct device *dev)
 	}
 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
+	clk_disable_unprepare(gpio->clk);
+
 	return 0;
 }
 
@@ -768,6 +783,9 @@ static int dwapb_gpio_resume(struct device *dev)
 	unsigned long flags;
 	int i;
 
+	if (!IS_ERR(gpio->clk))
+		clk_prepare_enable(gpio->clk);
+
 	spin_lock_irqsave(&gc->bgpio_lock, flags);
 	for (i = 0; i < gpio->nr_ports; i++) {
 		unsigned int offset;
-- 
2.7.4

Re: [PATCH v2] gpio: dwapb: Add support for a bus clock

[Andy Shevchenko]

On Mon, Mar 12, 2018 at 8:30 PM, Phil Edworthy
<phil.edworthy@renesas.com> wrote:
> Enable an optional bus clock provided by DT.

FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

(Assuming it has been tested on clock-less cases)

> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
> ---
> v2:
>  - Fix include order.
>  - Use a clock name.
>  - Check errors from clk_prepare_enable()
>  - Add calls to enable/disable the clock in PM
> ---
>  drivers/gpio/gpio-dwapb.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index b0704a8..226977f 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -8,8 +8,9 @@
>   * All enquiries to support@picochip.com
>   */
>  #include <linux/acpi.h>
> -#include <linux/gpio/driver.h>
> +#include <linux/clk.h>
>  #include <linux/err.h>
> +#include <linux/gpio/driver.h>
>  #include <linux/init.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
> @@ -98,6 +99,7 @@ struct dwapb_gpio {
>         struct irq_domain       *domain;
>         unsigned int            flags;
>         struct reset_control    *rst;
> +       struct clk              *clk;
>  };
>
>  static inline u32 gpio_reg_v2_convert(unsigned int offset)
> @@ -670,6 +672,16 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
>         if (IS_ERR(gpio->regs))
>                 return PTR_ERR(gpio->regs);
>
> +       /* Optional bus clock */
> +       gpio->clk = devm_clk_get(&pdev->dev, "bus");
> +       if (!IS_ERR(gpio->clk)) {
> +               err = clk_prepare_enable(gpio->clk);
> +               if (err) {
> +                       dev_info(&pdev->dev, "Cannot enable clock\n");
> +                       return err;
> +               }
> +       }
> +
>         gpio->flags = 0;
>         if (dev->of_node) {
>                 const struct of_device_id *of_devid;
> @@ -712,6 +724,7 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
>         dwapb_gpio_unregister(gpio);
>         dwapb_irq_teardown(gpio);
>         reset_control_assert(gpio->rst);
> +       clk_disable_unprepare(gpio->clk);
>
>         return 0;
>  }
> @@ -757,6 +770,8 @@ static int dwapb_gpio_suspend(struct device *dev)
>         }
>         spin_unlock_irqrestore(&gc->bgpio_lock, flags);
>
> +       clk_disable_unprepare(gpio->clk);
> +
>         return 0;
>  }
>
> @@ -768,6 +783,9 @@ static int dwapb_gpio_resume(struct device *dev)
>         unsigned long flags;
>         int i;
>
> +       if (!IS_ERR(gpio->clk))
> +               clk_prepare_enable(gpio->clk);
> +
>         spin_lock_irqsave(&gc->bgpio_lock, flags);
>         for (i = 0; i < gpio->nr_ports; i++) {
>                 unsigned int offset;
> --
> 2.7.4
>



-- 
With Best Regards,
Andy Shevchenko

RE: [PATCH v2] gpio: dwapb: Add support for a bus clock

[Phil Edworthy]

Hi Andy,

On 13 March 2018 16:36, Andy Shevchenko wrote:
> On Mon, Mar 12, 2018 at 8:30 PM, Phil Edworthy
> <phil.edworthy@renesas.com> wrote:
> > Enable an optional bus clock provided by DT.
> 
> FWIW,
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Thanks!
 
> (Assuming it has been tested on clock-less cases)
I hacked together a test where the bus clock for the device I have
is always on, and the clock for this driver is not present in the DTB.
Whilst not ideal, it does test the clock-less case.

Thanks
Phil
 
> > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
> > ---
> > v2:
> >  - Fix include order.
> >  - Use a clock name.
> >  - Check errors from clk_prepare_enable()
> >  - Add calls to enable/disable the clock in PM
> > ---
> >  drivers/gpio/gpio-dwapb.c | 20 +++++++++++++++++++-
> >  1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> > index b0704a8..226977f 100644
> > --- a/drivers/gpio/gpio-dwapb.c
> > +++ b/drivers/gpio/gpio-dwapb.c
> > @@ -8,8 +8,9 @@
> >   * All enquiries to support@picochip.com
> >   */
> >  #include <linux/acpi.h>
> > -#include <linux/gpio/driver.h>
> > +#include <linux/clk.h>
> >  #include <linux/err.h>
> > +#include <linux/gpio/driver.h>
> >  #include <linux/init.h>
> >  #include <linux/interrupt.h>
> >  #include <linux/io.h>
> > @@ -98,6 +99,7 @@ struct dwapb_gpio {
> >         struct irq_domain       *domain;
> >         unsigned int            flags;
> >         struct reset_control    *rst;
> > +       struct clk              *clk;
> >  };
> >
> >  static inline u32 gpio_reg_v2_convert(unsigned int offset) @@ -670,6
> > +672,16 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
> >         if (IS_ERR(gpio->regs))
> >                 return PTR_ERR(gpio->regs);
> >
> > +       /* Optional bus clock */
> > +       gpio->clk = devm_clk_get(&pdev->dev, "bus");
> > +       if (!IS_ERR(gpio->clk)) {
> > +               err = clk_prepare_enable(gpio->clk);
> > +               if (err) {
> > +                       dev_info(&pdev->dev, "Cannot enable clock\n");
> > +                       return err;
> > +               }
> > +       }
> > +
> >         gpio->flags = 0;
> >         if (dev->of_node) {
> >                 const struct of_device_id *of_devid; @@ -712,6 +724,7
> > @@ static int dwapb_gpio_remove(struct platform_device *pdev)
> >         dwapb_gpio_unregister(gpio);
> >         dwapb_irq_teardown(gpio);
> >         reset_control_assert(gpio->rst);
> > +       clk_disable_unprepare(gpio->clk);
> >
> >         return 0;
> >  }
> > @@ -757,6 +770,8 @@ static int dwapb_gpio_suspend(struct device *dev)
> >         }
> >         spin_unlock_irqrestore(&gc->bgpio_lock, flags);
> >
> > +       clk_disable_unprepare(gpio->clk);
> > +
> >         return 0;
> >  }
> >
> > @@ -768,6 +783,9 @@ static int dwapb_gpio_resume(struct device *dev)
> >         unsigned long flags;
> >         int i;
> >
> > +       if (!IS_ERR(gpio->clk))
> > +               clk_prepare_enable(gpio->clk);
> > +
> >         spin_lock_irqsave(&gc->bgpio_lock, flags);
> >         for (i = 0; i < gpio->nr_ports; i++) {
> >                 unsigned int offset;
> > --
> > 2.7.4
> >
> 
> 
> 
> --
> With Best Regards,
> Andy Shevchenko

Re: [PATCH v2] gpio: dwapb: Add support for a bus clock

[Linus Walleij]

On Mon, Mar 12, 2018 at 7:30 PM, Phil Edworthy
<phil.edworthy@renesas.com> wrote:

> Enable an optional bus clock provided by DT.
>
> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
> ---
> v2:
>  - Fix include order.
>  - Use a clock name.
>  - Check errors from clk_prepare_enable()
>  - Add calls to enable/disable the clock in PM

Patch applied with Andy's review tag.

Yours,
Linus Walleij