From: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
Currently the in-band alerts for SoundWire peripherals can only
be communicated to the driver through the interrupt_callback
function. This however is slightly inconvient for devices that wish to
share IRQ handling code between SoundWire and I2C/SPI, the later would
normally register an IRQ handler with the IRQ subsystem. However there
is no reason the SoundWire in-band IRQs can not also be communicated
as an actual IRQ to the driver.
Add support for SoundWire peripherals to register a normal IRQ handler
to receive SoundWire in-band alerts, allowing code to be shared across
control buses. Note that we allow users to use both the
interrupt_callback and the IRQ handler, this is useful for devices which
must clear additional chip specific SoundWire registers that are not a
part of the normal IRQ flow, or the SoundWire specification.
Signed-off-by: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
---
Changes since v1:
- Update commit message
Thanks,
Charles
drivers/soundwire/bus.c | 31 +++++++++++++++++++++++++++++++
drivers/soundwire/bus_type.c | 12 ++++++++++++
include/linux/soundwire/sdw.h | 9 +++++++++
3 files changed, 52 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 1ea6a64f8c4a5..30cd03757aafe 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -3,6 +3,7 @@
#include <linux/acpi.h>
#include <linux/delay.h>
+#include <linux/irq.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_runtime.h>
#include <linux/soundwire/sdw_registers.h>
@@ -25,6 +26,23 @@ static int sdw_get_id(struct sdw_bus *bus)
return 0;
}
+static int sdw_irq_map(struct irq_domain *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct sdw_bus *bus = h->host_data;
+
+ irq_set_chip_data(virq, bus);
+ irq_set_chip(virq, &bus->irq_chip);
+ irq_set_nested_thread(virq, 1);
+ irq_set_noprobe(virq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops sdw_domain_ops = {
+ .map = sdw_irq_map,
+};
+
/**
* sdw_bus_master_add() - add a bus Master instance
* @bus: bus instance
@@ -142,6 +160,13 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
bus->params.curr_bank = SDW_BANK0;
bus->params.next_bank = SDW_BANK1;
+ bus->irq_chip.name = dev_name(bus->dev);
+ bus->domain = irq_domain_add_linear(NULL, SDW_MAX_DEVICES, &sdw_domain_ops, bus);
+ if (!bus->domain) {
+ dev_err(bus->dev, "Failed to add IRQ domain\n");
+ return -EINVAL;
+ }
+
return 0;
}
EXPORT_SYMBOL(sdw_bus_master_add);
@@ -178,6 +203,9 @@ static int sdw_delete_slave(struct device *dev, void *data)
void sdw_bus_master_delete(struct sdw_bus *bus)
{
device_for_each_child(bus->dev, NULL, sdw_delete_slave);
+
+ irq_domain_remove(bus->domain);
+
sdw_master_device_del(bus);
sdw_bus_debugfs_exit(bus);
@@ -1711,6 +1739,9 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
struct device *dev = &slave->dev;
struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
+ if (slave->prop.use_domain_irq && slave->irq)
+ handle_nested_irq(slave->irq);
+
if (drv->ops && drv->ops->interrupt_callback) {
slave_intr.sdca_cascade = sdca_cascade;
slave_intr.control_port = clear;
diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
index 1f43ee848eac8..fafbc284e82da 100644
--- a/drivers/soundwire/bus_type.c
+++ b/drivers/soundwire/bus_type.c
@@ -122,6 +122,12 @@ static int sdw_drv_probe(struct device *dev)
if (drv->ops && drv->ops->read_prop)
drv->ops->read_prop(slave);
+ if (slave->prop.use_domain_irq) {
+ slave->irq = irq_create_mapping(slave->bus->domain, slave->dev_num);
+ if (!slave->irq)
+ dev_warn(dev, "Failed to map IRQ\n");
+ }
+
/* init the sysfs as we have properties now */
ret = sdw_slave_sysfs_init(slave);
if (ret < 0)
@@ -166,7 +172,13 @@ static int sdw_drv_remove(struct device *dev)
int ret = 0;
mutex_lock(&slave->sdw_dev_lock);
+
slave->probed = false;
+
+ if (slave->prop.use_domain_irq)
+ irq_dispose_mapping(irq_find_mapping(slave->bus->domain,
+ slave->dev_num));
+
mutex_unlock(&slave->sdw_dev_lock);
if (drv->remove)
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index ef645de13ae93..c3ab5e5f9cfa4 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -5,6 +5,8 @@
#define __SOUNDWIRE_H
#include <linux/bug.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
#include <linux/mod_devicetable.h>
#include <linux/bitfield.h>
@@ -369,6 +371,7 @@ struct sdw_dpn_prop {
* @clock_reg_supported: the Peripheral implements the clock base and scale
* registers introduced with the SoundWire 1.2 specification. SDCA devices
* do not need to set this boolean property as the registers are required.
+ * @use_domain_irq: call actual IRQ handler on slave, as well as callback
*/
struct sdw_slave_prop {
u32 mipi_revision;
@@ -393,6 +396,7 @@ struct sdw_slave_prop {
u8 scp_int1_mask;
u32 quirks;
bool clock_reg_supported;
+ bool use_domain_irq;
};
#define SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY BIT(0)
@@ -640,6 +644,7 @@ struct sdw_slave_ops {
* struct sdw_slave - SoundWire Slave
* @id: MIPI device ID
* @dev: Linux device
+ * @irq: IRQ number
* @status: Status reported by the Slave
* @bus: Bus handle
* @prop: Slave properties
@@ -669,6 +674,7 @@ struct sdw_slave_ops {
struct sdw_slave {
struct sdw_slave_id id;
struct device dev;
+ int irq;
enum sdw_slave_status status;
struct sdw_bus *bus;
struct sdw_slave_prop prop;
@@ -883,6 +889,7 @@ struct sdw_master_ops {
* is used to compute and program bus bandwidth, clock, frame shape,
* transport and port parameters
* @debugfs: Bus debugfs
+ * @domain: IRQ domain
* @defer_msg: Defer message
* @clk_stop_timeout: Clock stop timeout computed
* @bank_switch_timeout: Bank switch timeout computed
@@ -916,6 +923,8 @@ struct sdw_bus {
#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs;
#endif
+ struct irq_chip irq_chip;
+ struct irq_domain *domain;
struct sdw_defer defer_msg;
unsigned int clk_stop_timeout;
u32 bank_switch_timeout;
--
2.30.2
