ASoC: cs42l42: Add SOFT_RESET_REBOOT register

The SOFT_RESET_REBOOT register is needed to recover CS42L42 state after
a Soundwire bus reset.

This is required to be set whenever there is severe/hard bus reset.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20230127165111.3010960-3-sbinding@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/cs42l42.h

@@ -34,6 +34,7 @@
 #define CS42L42_PAGE_24		0x2400
 #define CS42L42_PAGE_25		0x2500
 #define CS42L42_PAGE_26		0x2600
+#define CS42L42_PAGE_27		0x2700
 #define CS42L42_PAGE_28		0x2800
 #define CS42L42_PAGE_29		0x2900
 #define CS42L42_PAGE_2A		0x2A00
@@ -720,6 +721,10 @@
 
 #define CS42L42_SRC_SDOUT_FS		(CS42L42_PAGE_26 + 0x09)
 
+/* Page 0x27 DMA */
+#define CS42L42_SOFT_RESET_REBOOT	(CS42L42_PAGE_27 + 0x01)
+#define CS42L42_SFT_RST_REBOOT_MASK	BIT(1)
+
 /* Page 0x28 S/PDIF Registers */
 #define CS42L42_SPDIF_CTL1		(CS42L42_PAGE_28 + 0x01)
 #define CS42L42_SPDIF_CTL2		(CS42L42_PAGE_28 + 0x02)

sound/soc/codecs/cs42l42.c

@@ -293,6 +293,7 @@ bool cs42l42_readable_register(struct device *dev, unsigned int reg)
 	case CS42L42_SPDIF_SW_CTL1:
 	case CS42L42_SRC_SDIN_FS:
 	case CS42L42_SRC_SDOUT_FS:
+	case CS42L42_SOFT_RESET_REBOOT:
 	case CS42L42_SPDIF_CTL1:
 	case CS42L42_SPDIF_CTL2:
 	case CS42L42_SPDIF_CTL3:
@@ -358,6 +359,7 @@ bool cs42l42_volatile_register(struct device *dev, unsigned int reg)
 	case CS42L42_LOAD_DET_DONE:
 	case CS42L42_DET_STATUS1:
 	case CS42L42_DET_STATUS2:
+	case CS42L42_SOFT_RESET_REBOOT:
 		return true;
 	default:
 		return false;