Tero Kristo <t-kristo@xxxxxx> writes:
> PRCM interrupt handler will now parse registered pads to see whether there
> is an active wakeup event. If this is the case, the corresponding interrupt
> will be triggered. This can be used for example with UART driver to register
> PAD wakeup event for the UART RX pin, and when this happens, UART interrupt
> will be triggered.
>
> Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
> ---
> arch/arm/mach-omap2/prcm.c | 50 ++++++++++++++++++++++++++++++++
> arch/arm/plat-omap/include/plat/prcm.h | 1 +
> 2 files changed, 51 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/prcm.c b/arch/arm/mach-omap2/prcm.c
> index 362c59c..cc92064 100644
> --- a/arch/arm/mach-omap2/prcm.c
> +++ b/arch/arm/mach-omap2/prcm.c
> @@ -53,6 +53,15 @@ static struct omap_prcm_irq *omap_prcm_irqs;
> /* Number of entries in omap_prcm_irqs */
> static int omap_prcm_irqs_nr;
>
> +/* PAD handlers list */
> +struct pad_def {
> + u32 pad;
> + unsigned int irq;
> + struct list_head node;
> +};
> +
> +static LIST_HEAD(pad_handler_list);
> +
> /* Pointers to either OMAP3 or OMAP4 specific functions */
> static void (*omap_prcm_mask_event)(unsigned event);
> static void (*omap_prcm_unmask_event)(unsigned event);
> @@ -84,6 +93,25 @@ static struct irq_chip prcm_irq_chip = {
> .irq_unmask = prcm_irq_unmask,
> };
>
> +
> +/*
> + * Handler for PAD irqs, called from PRCM interrupt handler
> + */
> +static void omap_prcm_handle_pad_irqs(void)
> +{
> + struct pad_def *def;
> + u16 val = 0;
minor: insert blank line between variables and code
> + list_for_each_entry(def, &pad_handler_list, node) {
> + /* Read padconf value based on cpu type */
> + if (cpu_is_omap34xx())
> + val = omap_ctrl_readw(def->pad);
We need to avoid cpu_is_* checks in driver code.
What we'll need is another control-module API for reading a padconf, and
the SoC-specific implementation can be managed by the control module code.
> + /* if pad wakeupevent is active, fire registered IRQ */
> + if (val & OMAP3_PADCONF_WAKEUPEVENT0)
Does this need to be masked with the wakeup enable? IOW, is it possible
to find an pad with a masked wakeup event? Might be worth double
checking the TRM on that one, but masking with the enable would not hurt
here.
> + generic_handle_irq(def->irq);
Nice, I wish I thought of that! I was trying to figure out how to SW
trigger a hard IRQ, but this is much better and doesn't rely on any
hardware feature. Sometimes the simplest solution is the best. :)
> + }
> +}
> +
> /*
> * PRCM Interrupt Handler
> *
> @@ -106,6 +134,9 @@ static void prcm_irq_handler(unsigned int irq, struct irq_desc *desc)
> unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG];
> struct irq_chip *chip = irq_desc_get_chip(desc);
>
> + /* Handle PAD events first, we don't want to ack them before parse */
> + omap_prcm_handle_pad_irqs();
> +
Handling here is fine, but it's not terribly clear on first read where
the events are eventually cleared.
I see now that they are cleared upon entry into the idle path, but I
think it would help readability if they were cleared after this handler
runs.
> /*
> * Loop until all pending irqs are handled, since
> * generic_handle_irq(), called by prcm_irq_handle_virtirqs()
> @@ -153,6 +184,25 @@ int omap_prcm_event_to_irq(const char *name)
> }
>
> /*
> + * Register interrupt handler for a given pad. When the PRCM interrupt
> + * handler detects wakeupevent on the corresponding pad, the IRQ will
> + * be triggered.
This comment needs a minor change: technically, it's not the IRQ that is
triggered but the ISR for that IRQ will be called.
The same change should be made in the changelog.
> + */
> +int omap_prcm_register_pad_irq(u32 pad, unsigned int irq)
> +{
> + struct pad_def *def;
> +
> + def = kmalloc(sizeof(struct pad_def), GFP_ATOMIC);
> + if (!def)
> + return -ENOMEM;
> +
> + def->pad = pad;
> + def->irq = irq;
> + list_add(&def->node, &pad_handler_list);
> + return 0;
> +}
This wants an unregister counterpart.
> +/*
> * Prepare the array of PRCM events corresponding to the current SoC,
> * and set-up the chained interrupt handler mechanism.
> */
> diff --git a/arch/arm/plat-omap/include/plat/prcm.h b/arch/arm/plat-omap/include/plat/prcm.h
> index 5785555..789eb17 100644
> --- a/arch/arm/plat-omap/include/plat/prcm.h
> +++ b/arch/arm/plat-omap/include/plat/prcm.h
> @@ -72,6 +72,7 @@ void omap4_prcm_pending_events(unsigned long *pending);
> int omap_prcm_event_to_irq(const char *name);
> int omap_prcm_irq_init(void);
> void omap_prcm_irq_cleanup(void);
> +int omap_prcm_register_pad_irq(u32 pad, unsigned int irq);
> u32 omap_prcm_get_reset_sources(void);
> int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, u8 idlest,
> const char *name);
Kevin
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