Re: [PATCH] ASoC: cs42xx8: Add SPI bus support for CS42448/CS42888 codec

[Charles Keepax <ckeepax@opensource.cirrus.com>]

On Tue, Jun 02, 2026 at 06:25:33AM +0000, Chancel Liu (OSS) wrote:
> > > The existing cs42xx8 driver only supported I2C control interface.
> > > Add SPI bus support for the Cirrus Logic CS42448/CS42888 Audio CODEC.
> > 
> > > + * The SPI frame is 3 bytes:
> > > + *   Byte 0: chip address [7:1] = 1001111, bit[0] = R/W (0=write,
> > 1=read)
> > > + *           Write: 0x9E,  Read: 0x9F
> > > + *   Byte 1: MAP - Memory Address Pointer
> > > + *           bit[7] = INCR (auto-increment for burst), bits[6:0] =
> > address
> > 
> > > + * We configure reg_bits=16 so that regmap treats the address field as
> > 2 bytes
> > > + * (big-endian). The chip address byte (0x9E/0x9F) is placed in the
> > high byte
> > > + * via write_flag_mask / read_flag_mask, and the MAP register address
> > occupies
> > > + * the low byte. This produces the correct 3-byte on-wire frame without
> > any
> > > + * custom bus implementation:
> > > + *
> > > + *   write: [0x9E, MAP_addr, data]
> > > + *   read:  [0x9F, MAP_addr] -> [data]
> > 
> > What about INCR?
> > 
> 
> Indeed. This patch doesn't handle INCR. I'll enable INCR after reworking
> on write_flag_mask/read_flag_mask.
> 

I don't think the driver does anything that reads/writes more
than a single register, so one could probably just set
use_single_read/write and punt on handling INCR for now.

> > > +static const struct of_device_id cs42xx8_of_match[] = {
> > > +	{ .compatible = "cirrus,cs42448", .data = &cs42448_data, },
> > > +	{ .compatible = "cirrus,cs42888", .data = &cs42888_data, },
> > > +	{ /* sentinel */ }
> > > +};
> > > +MODULE_DEVICE_TABLE(of, cs42xx8_of_match);
> > 
> > This should have an update to the bindings as well.

Thanks sorry missed that.

Thanks,
Charles