From: Bartosz Golaszewski <[email protected]> Provide a helper allowing users to register a notifier block with a simulator. For now the only event we're notifying about is a change in type configuration.
This is required by the gpio-mockup module which wants to track the state of GPIO lines and simulate rising and falling edge interrupts. Signed-off-by: Bartosz Golaszewski <[email protected]> --- include/linux/irq_sim.h | 22 ++++++++++++++++++---- kernel/irq/irq_sim.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+), 4 deletions(-) diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h index 4500d453a63e..e076693d0af7 100644 --- a/include/linux/irq_sim.h +++ b/include/linux/irq_sim.h @@ -8,12 +8,21 @@ #include <linux/irq_work.h> #include <linux/device.h> +#include <linux/notifier.h> /* * Provides a framework for allocating simulated interrupts which can be * requested like normal irqs and enqueued from process context. */ +#define IRQ_SIM_TYPE_CHANGED 1 + +/* Passed to notifier callbacks when type changes. */ +struct irq_sim_irq_type { + unsigned int offset; + unsigned int type; +}; + struct irq_sim_work_ctx { struct irq_work work; unsigned long *pending; @@ -22,13 +31,16 @@ struct irq_sim_work_ctx { struct irq_sim_irq_ctx { int irqnum; bool enabled; + struct irq_sim *parent; + struct irq_sim_irq_type type; }; struct irq_sim { - struct irq_sim_work_ctx work_ctx; - int irq_base; - unsigned int irq_count; - struct irq_sim_irq_ctx *irqs; + struct irq_sim_work_ctx work_ctx; + int irq_base; + unsigned int irq_count; + struct irq_sim_irq_ctx *irqs; + struct atomic_notifier_head notifier; }; int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs); @@ -37,5 +49,7 @@ int devm_irq_sim_init(struct device *dev, struct irq_sim *sim, void irq_sim_fini(struct irq_sim *sim); void irq_sim_fire(struct irq_sim *sim, unsigned int offset); int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset); +int irq_sim_notifier_register(struct irq_sim *sim, + struct notifier_block *nb); #endif /* _LINUX_IRQ_SIM_H */ diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c index 98a20e1594ce..a55641e78125 100644 --- a/kernel/irq/irq_sim.c +++ b/kernel/irq/irq_sim.c @@ -25,10 +25,34 @@ 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); + struct irq_sim *sim = irq_ctx->parent; + int rv; + + /* Only support rising and falling edge types. */ + if (type & ~IRQ_TYPE_EDGE_BOTH) + return -EINVAL; + + irq_ctx->type.type = type; + + rv = atomic_notifier_call_chain(&sim->notifier, + IRQ_SIM_TYPE_CHANGED, + &irq_ctx->type); + if (rv < 0) { + pr_err("%s: error calling the type notifier chain\n", __func__); + return rv; + } + + return 0; +} + static struct irq_chip irq_sim_irqchip = { .name = "irq_sim", .irq_mask = irq_sim_irqmask, .irq_unmask = irq_sim_irqunmask, + .irq_set_type = irq_sim_set_type, }; static void irq_sim_handle_irq(struct irq_work *work) @@ -83,7 +107,9 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) for (i = 0; i < num_irqs; i++) { sim->irqs[i].irqnum = sim->irq_base + i; + sim->irqs[i].parent = sim; sim->irqs[i].enabled = false; + sim->irqs[i].type.offset = i; irq_set_chip(sim->irq_base + i, &irq_sim_irqchip); irq_set_chip_data(sim->irq_base + i, &sim->irqs[i]); irq_set_handler(sim->irq_base + i, &handle_simple_irq); @@ -91,6 +117,7 @@ int irq_sim_init(struct irq_sim *sim, unsigned int num_irqs) IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); } + ATOMIC_INIT_NOTIFIER_HEAD(&sim->notifier); init_irq_work(&sim->work_ctx.work, irq_sim_handle_irq); sim->irq_count = num_irqs; @@ -180,3 +207,16 @@ int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset) return sim->irqs[offset].irqnum; } EXPORT_SYMBOL_GPL(irq_sim_irqnum); + +/** + * irq_sim_notifier_register - Subscribe for interrupt simulator events. + * + * @sim: The interrupt simulator object. + * @nb: Notifier block. + */ +int irq_sim_notifier_register(struct irq_sim *sim, + struct notifier_block *nb) +{ + return atomic_notifier_chain_register(&sim->notifier, nb); +} +EXPORT_SYMBOL_GPL(irq_sim_notifier_register); -- 2.20.1
