u-boot/drivers/misc/irq_sandbox.c
Simon Glass 025543554c dm: irq: Add support for requesting interrupts
At present driver model supports the IRQ uclass but there is no way to
request a particular interrupt for a driver.

Add a mechanism, similar to clock and reset, to read the interrupts
required by a device from the device tree and to request those interrupts.

U-Boot itself does not have interrupt-driven handlers, so just provide a
means to read and clear an interrupt. This can be useful to handle
peripherals which must use an interrupt to determine when data is
available, for example.

Bring over the basic binding file as well, from Linux v5.4. Note that the
older binding is not supported in U-Boot; the newer 'special form' must be
used.

Add a simple test of the new functionality.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-07 22:46:32 +08:00

96 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Sandbox driver for interrupts
*
* Copyright 2019 Google LLC
*/
#include <common.h>
#include <dm.h>
#include <irq.h>
#include <asm/test.h>
/**
* struct sandbox_irq_priv - private data for this driver
*
* @count: Counts the number calls to the read_and_clear() method
* @pending: true if an interrupt is pending, else false
*/
struct sandbox_irq_priv {
int count;
bool pending;
};
static int sandbox_set_polarity(struct udevice *dev, uint irq, bool active_low)
{
if (irq > 10)
return -EINVAL;
return 0;
}
static int sandbox_route_pmc_gpio_gpe(struct udevice *dev, uint pmc_gpe_num)
{
if (pmc_gpe_num > 10)
return -ENOENT;
return pmc_gpe_num + 1;
}
static int sandbox_snapshot_polarities(struct udevice *dev)
{
return 0;
}
static int sandbox_restore_polarities(struct udevice *dev)
{
return 0;
}
static int sandbox_irq_read_and_clear(struct irq *irq)
{
struct sandbox_irq_priv *priv = dev_get_priv(irq->dev);
if (irq->id != SANDBOX_IRQN_PEND)
return -EINVAL;
priv->count++;
if (priv->pending) {
priv->pending = false;
return 1;
}
if (!(priv->count % 3))
priv->pending = true;
return 0;
}
static int sandbox_irq_of_xlate(struct irq *irq,
struct ofnode_phandle_args *args)
{
irq->id = args->args[0];
return 0;
}
static const struct irq_ops sandbox_irq_ops = {
.route_pmc_gpio_gpe = sandbox_route_pmc_gpio_gpe,
.set_polarity = sandbox_set_polarity,
.snapshot_polarities = sandbox_snapshot_polarities,
.restore_polarities = sandbox_restore_polarities,
.read_and_clear = sandbox_irq_read_and_clear,
.of_xlate = sandbox_irq_of_xlate,
};
static const struct udevice_id sandbox_irq_ids[] = {
{ .compatible = "sandbox,irq", SANDBOX_IRQT_BASE },
{ }
};
U_BOOT_DRIVER(sandbox_irq_drv) = {
.name = "sandbox_irq",
.id = UCLASS_IRQ,
.of_match = sandbox_irq_ids,
.ops = &sandbox_irq_ops,
.priv_auto_alloc_size = sizeof(struct sandbox_irq_priv),
};