soundwire: mipi-disco: add new properties from 2.0 spec

The DisCo for SoundWire 2.0 spec adds support for new
'mipi-sdw-sdca-interrupt-register-list' and
'mipi-sdw-commit-register-supported'.

This patch only adds the definitions and property reads, but the use
of these properties will come at some point in the future when needed.

Note a slight conceptual disconnect between the MIPI DisCo definition
of a boolean property and the Linux implementation. The latter only
checks the presence of the property to set its value to 'true',
whereas the MIPI definitions allow for a property with a 'false'
value. This patch relies on a read_u8() even if the DisCo property is
defined as boolean.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

drivers/soundwire/mipi_disco.c

@@ -378,6 +378,19 @@ int sdw_slave_read_prop(struct sdw_slave *slave)
 	device_property_read_u32(dev, "mipi-sdw-sink-port-list",
 				 &prop->sink_ports);
 
+	device_property_read_u32(dev, "mipi-sdw-sdca-interrupt-register-list",
+				 &prop->sdca_interrupt_register_list);
+
+	/*
+	 * The specification defines the property value as boolean, but
+	 * the value can be defined as zero. This is not aligned the
+	 * implementation of device_property_read_bool() which only checks
+	 * the presence of the property.
+	 * Let's use read_u8 to work-around this conceptual disconnect.
+	 */
+	device_property_read_u8(dev, "mipi-sdw-commit-register-supported",
+				&prop->commit_register_supported);
+
 	/*
 	 * Read dp0 properties - we don't rely on the 'mipi-sdw-dp-0-supported'
 	 * property since the 'mipi-sdw-dp0-subproperties' property is logically

include/linux/soundwire/sdw.h

@@ -341,6 +341,9 @@ struct sdw_dpn_prop {
  * 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
+ * @sdca_interrupt_register_list: indicates which sets of SDCA interrupt status
+ * and masks are supported
+ * @commit_register_supported: is PCP_Commit register supported
  */
 struct sdw_slave_prop {
 	u32 mipi_revision;
@@ -366,6 +369,8 @@ struct sdw_slave_prop {
 	u32 quirks;
 	bool clock_reg_supported;
 	bool use_domain_irq;
+	u32 sdca_interrupt_register_list;
+	u8 commit_register_supported;
 };
 
 #define SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY	BIT(0)