On Fri, Oct 30, 2020 at 04:49:55AM +0800, Bard Liao wrote: > From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> > > The upcoming SDCA (SoundWire Device Class Audio) specification defines > a hierarchical encoding to interface with Class-defined capabilities. > > The specification is not yet accessible to the general public but this > information is released with explicit permission from the MIPI Board > to avoid delays with SDCA support on Linux platforms. > > A block of 64 MBytes of register addresses are allocated to SDCA > controls, starting at address 0x40000000. The 26 LSBs which identify > individual controls are set based on the following variables: > > - Function Number. An SCDA device can be split in up to 8 independent > Functions. Each of these Functions is described in the SDCA > specification, e.g. Smart Amplifier, Smart Microphone, Simple > Microphone, Jack codec, HID, etc. > > - Entity Number. Within each Function, an Entity is an identifiable > block. Up to 127 Entities are connected in a pre-defined > graph (similar to USB), with Entity0 reserved for Function-level > configurations. In contrast to USB, the SDCA spec pre-defines > Function Types, topologies, and allowed options, i.e. the degree of > freedom is not unlimited to limit the possibility of errors in > descriptors leading to software quirks. > > - Control Selector. Within each Entity, the SDCA specification defines > 48 controls such as Mute, Gain, AGC, etc, and 16 implementation > defined ones. Some Control Selectors might be used for low-level > platform setup, and other exposed to applications and users. Note > that the same Control Selector capability, e.g. Latency control, > might be located at different offsets in different entities, the > Control Selector mapping is Entity-specific. > > - Control Number. Some Control Selectors allow channel-specific values > to be set, with up to 64 channels allowed. This is mostly used for > volume control. > > - Current/Next values. Some Control Selectors are > 'Dual-Ranked'. Software may either update the Current value directly > for immediate effect. Alternatively, software may write into the > 'Next' values and update the SoundWire 1.2 'Commit Groups' register > to copy 'Next' values into 'Current' ones in a synchronized > manner. This is different from bank switching which is typically > used to change the bus configuration only. > > - MBQ. the Multi-Byte Quantity bit is used to provide atomic updates > when accessing more that one byte, for example a 16-bit volume > control would be updated consistently, the intermediate values > mixing old MSB with new LSB are not applied. > > These 6 parameters are used to build a 32-bit address to access the > desired Controls. Because of address range, paging is required, but > the most often used parameter values are placed in the lower 16 bits > of the address. This helps to keep the paging registers constant while > updating Controls for a specific Device/Function. > > Reviewed-by: Rander Wang <rander.wang@xxxxxxxxxxxxxxx> > Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx> > Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> > Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> > Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> > --- > Changelog: > > v2: > - add SDW_SDCA_MBQ_CTL > > v3: > - add SDW_SDCA_NEXT_CTL > > --- > include/linux/soundwire/sdw_registers.h | 32 +++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/include/linux/soundwire/sdw_registers.h b/include/linux/soundwire/sdw_registers.h > index f420e8059779..e14dff9a9c7f 100644 > --- a/include/linux/soundwire/sdw_registers.h > +++ b/include/linux/soundwire/sdw_registers.h > @@ -298,4 +298,36 @@ > #define SDW_CASC_PORT_MASK_INTSTAT3 1 > #define SDW_CASC_PORT_REG_OFFSET_INTSTAT3 2 > > +/* > + * v1.2 device - SDCA address mapping > + * > + * Spec definition > + * Bits Contents > + * 31 0 (required by addressing range) > + * 30:26 0b10000 (Control Prefix) > + * 25 0 (Reserved) > + * 24:22 Function Number [2:0] > + * 21 Entity[6] > + * 20:19 Control Selector[5:4] > + * 18 0 (Reserved) > + * 17:15 Control Number[5:3] > + * 14 Next > + * 13 MBQ > + * 12:7 Entity[5:0] > + * 6:3 Control Selector[3:0] > + * 2:0 Control Number[2:0] > + */ > + > +#define SDW_SDCA_CTL(fun, ent, ctl, ch) (BIT(30) | \ > + (((fun) & 0x7) << 22) | \ > + (((ent) & 0x40) << 15) | \ > + (((ent) & 0x3f) << 7) | \ > + (((ctl) & 0x30) << 15) | \ > + (((ctl) & 0x0f) << 3) | \ > + (((ch) & 0x38) << 12) | \ > + ((ch) & 0x07)) > + > +#define SDW_SDCA_MBQ_CTL(reg) ((reg) | BIT(13)) > +#define SDW_SDCA_NEXT_CTL(reg) ((reg) | BIT(14)) > + > #endif /* __SDW_REGISTERS_H */ No users of these macros?
