wt., 12 lut 2019 o 11:06 Uwe Kleine-König
<u.kleine-koe...@pengutronix.de> napisał(a):
>
> On Tue, Feb 12, 2019 at 10:19:20AM +0100, Bartosz Golaszewski wrote:
> > wt., 12 lut 2019 o 10:10 Marc Zyngier <marc.zyng...@arm.com> napisał(a):
> > >
> > > On 29/01/2019 08:44, Bartosz Golaszewski wrote:
> > > > From: Bartosz Golaszewski <bgolaszew...@baylibre.com>
> > > >
> > > > Provide a more specialized variant of irq_sim_fire() that allows to
> > > > specify the type of the fired interrupt. The type is stored in the
> > > > dummy irq context struct via the set_type callback.
> > > >
> > > > Signed-off-by: Bartosz Golaszewski <bgolaszew...@baylibre.com>
> > > > ---
> > > > include/linux/irq_sim.h | 9 ++++++++-
> > > > kernel/irq/irq_sim.c | 26 ++++++++++++++++++++++----
> > > > 2 files changed, 30 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h
> > > > index b96c2f752320..647a6c8ffb31 100644
> > > > --- a/include/linux/irq_sim.h
> > > > +++ b/include/linux/irq_sim.h
> > > > @@ -23,6 +23,7 @@ struct irq_sim_work_ctx {
> > > >
> > > > struct irq_sim_irq_ctx {
> > > > bool enabled;
> > > > + unsigned int type;
> > > > };
> > > >
> > > > struct irq_sim {
> > > > @@ -37,7 +38,13 @@ int irq_sim_init(struct irq_sim *sim, unsigned int
> > > > num_irqs);
> > > > int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
> > > > unsigned int num_irqs);
> > > > void irq_sim_fini(struct irq_sim *sim);
> > > > -void irq_sim_fire(struct irq_sim *sim, unsigned int offset);
> > > > +void irq_sim_fire_type(struct irq_sim *sim,
> > > > + unsigned int offset, unsigned int type);
> > > > int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset);
> > > >
> > > > +static inline void irq_sim_fire(struct irq_sim *sim, unsigned int
> > > > offset)
> > > > +{
> > > > + irq_sim_fire_type(sim, offset, IRQ_TYPE_DEFAULT);
> > > > +}
> > > > +
> > > > #endif /* _LINUX_IRQ_SIM_H */
> > > > diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
> > > > index 2bcdbab1bc5a..e3160b5e59b8 100644
> > > > --- a/kernel/irq/irq_sim.c
> > > > +++ b/kernel/irq/irq_sim.c
> > > > @@ -25,6 +25,15 @@ static void irq_sim_irqunmask(struct irq_data *data)
> > > > irq_ctx->enabled = true;
> > > > }
> > > >
> > > > +static int irq_sim_set_type(struct irq_data *data, unsigned int type)
> > > > +{
> > > > + struct irq_sim_irq_ctx *irq_ctx =
> > > > irq_data_get_irq_chip_data(data);
> > > > +
> > > > + irq_ctx->type = type;
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > static void irq_sim_handle_irq(struct irq_work *work)
> > > > {
> > > > struct irq_sim_work_ctx *work_ctx;
> > > > @@ -107,6 +116,7 @@ int irq_sim_init(struct irq_sim *sim, unsigned int
> > > > num_irqs)
> > > > sim->chip.name = "irq_sim";
> > > > sim->chip.irq_mask = irq_sim_irqmask;
> > > > sim->chip.irq_unmask = irq_sim_irqunmask;
> > > > + sim->chip.irq_set_type = irq_sim_set_type;
> > > >
> > > > sim->work_ctx.pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
> > > > if (!sim->work_ctx.pending) {
> > > > @@ -192,21 +202,29 @@ irq_sim_get_ctx(struct irq_sim *sim, unsigned int
> > > > offset)
> > > > }
> > > >
> > > > /**
> > > > - * irq_sim_fire - Enqueue an interrupt.
> > > > + * irq_sim_fire_type - Enqueue an interrupt.
> > > > *
> > > > * @sim: The interrupt simulator object.
> > > > * @offset: Offset of the simulated interrupt which should be
> > > > fired.
> > > > + * @type: Type of the fired interrupt. Must be one of the following:
> > > > + * IRQ_TYPE_EDGE_RISING, IRQ_TYPE_EDGE_FALLING,
> > > > + * IRQ_TYPE_EDGE_BOTH, IRQ_TYPE_LEVEL_HIGH,
> > > > + * IRQ_TYPE_LEVEL_LOW, IRQ_TYPE_DEFAULT
> > > > */
> > > > -void irq_sim_fire(struct irq_sim *sim, unsigned int offset)
> > > > +void irq_sim_fire_type(struct irq_sim *sim,
> > > > + unsigned int offset, unsigned int type)
> > > > {
> > > > struct irq_sim_irq_ctx *ctx = irq_sim_get_ctx(sim, offset);
> > > >
> > > > - if (ctx->enabled) {
> > > > + /* Only care about relevant flags. */
> > > > + type &= IRQ_TYPE_SENSE_MASK;
> > > > +
> > > > + if (ctx->enabled && (ctx->type & type)) {
> > >
> > > I wonder how realistic this is, given that you do not track the release
> > > of a level. In short, mo matter what the type is, you treat everything
> > > as edge.
> > >
> > > What is the point of this?
> > >
> >
> > When userspace wants to monitor GPIO line interrupts, the GPIO
> > framework requests a threaded interrupt with IRQF_TRIGGER_FALLING,
> > IRQF_TRIGGER_RISING or both.
>
> I think the background of the question was: Why is there no support for
> level sensitive irqs?
>
> The userspace API has this limitation (also for no good reason I think).
>
Fair point. We also need support for programmable pull-up/down
resistors as it's something many users request. It's just a matter of
someone getting down to doing it. :)
Bart
