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

From: Phil Edworthy
Date: Tue Mar 13 2018 - 12:45:00 EST


Hi Andy,

On 13 March 2018 16:36, Andy Shevchenko wrote:
> On Mon, Mar 12, 2018 at 8:30 PM, Phil Edworthy
> <phil.edworthy@xxxxxxxxxxx> wrote:
> > Enable an optional bus clock provided by DT.
>
> FWIW,
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
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@xxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxx
> > */
> > #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