Commit 12a95123 authored by Lucas Tanure's avatar Lucas Tanure Committed by Lee Jones
Browse files

soundwire: bus: Allow SoundWire peripherals to register IRQ handlers 



Currently the in-band alerts for SoundWire peripherals can only
be communicated to the driver through the interrupt_callback
function. This however is slightly inconvenient 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: default avatarLucas Tanure <tanureal@opensource.cirrus.com>
Reviewed-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: default avatarBard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230804104602.395892-2-ckeepax@opensource.cirrus.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 06c2afb8

drivers/soundwire/bus.c

+32 −0
Original line number Diff line number Diff line
@@ -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
@@ -151,6 +169,14 @@ 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_create_linear(fwnode, 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);
@@ -187,6 +213,9 @@ 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);
@@ -1725,6 +1754,9 @@ 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;

drivers/soundwire/bus_type.c

+12 −0
Original line number Diff line number Diff line
@@ -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)

include/linux/soundwire/sdw.h

+9 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 


#include <linux/bug.h>

#include <linux/lockdep_types.h>

#include <linux/irq.h>

#include <linux/irqdomain.h>

#include <linux/mod_devicetable.h>

#include <linux/bitfield.h>
@@ -370,6 +372,7 @@ 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;
@@ -394,6 +397,7 @@ 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)
@@ -641,6 +645,7 @@ 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
@@ -670,6 +675,7 @@ 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;
@@ -885,6 +891,7 @@ 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
@@ -920,6 +927,8 @@ 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;