From: Lucas Tanure tanureal@opensource.cirrus.com
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@opensource.cirrus.com Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com ---
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;