[PATCH 3/3] mfd: cs42l43: Add support for new cs42l44 variant

From: Charles Keepax

Date: Wed Jul 08 2026 - 10:10:04 EST


The cs42l44 is a cost optimised variant of cs42l43b. Add basic support
for this new device.

Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/mfd/cs42l43-i2c.c | 2 ++
drivers/mfd/cs42l43-sdw.c | 1 +
drivers/mfd/cs42l43.c | 18 ++++++++++++------
include/linux/mfd/cs42l43-regs.h | 1 +
4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/cs42l43-i2c.c b/drivers/mfd/cs42l43-i2c.c
index bd9752d2cfc34..1af878c7a20b4 100644
--- a/drivers/mfd/cs42l43-i2c.c
+++ b/drivers/mfd/cs42l43-i2c.c
@@ -59,6 +59,7 @@ static int cs42l43_i2c_probe(struct i2c_client *i2c)
static const struct of_device_id cs42l43_of_match[] = {
{ .compatible = "cirrus,cs42l43", .data = (void *)CS42L43_DEVID_VAL },
{ .compatible = "cirrus,cs42l43b", .data = (void *)CS42L43B_DEVID_VAL },
+ { .compatible = "cirrus,cs42l44", .data = (void *)CS42L43B_DEVID_VAL },
{ }
};
MODULE_DEVICE_TABLE(of, cs42l43_of_match);
@@ -68,6 +69,7 @@ MODULE_DEVICE_TABLE(of, cs42l43_of_match);
static const struct acpi_device_id cs42l43_acpi_match[] = {
{ .id = "CSC4243", .driver_data = CS42L43_DEVID_VAL },
{ .id = "CSC2A3B", .driver_data = CS42L43B_DEVID_VAL },
+ { .id = "CSC4244", .driver_data = CS42L43B_DEVID_VAL },
{ }
};
MODULE_DEVICE_TABLE(acpi, cs42l43_acpi_match);
diff --git a/drivers/mfd/cs42l43-sdw.c b/drivers/mfd/cs42l43-sdw.c
index 6ccfdcd3f6698..81dd19df53685 100644
--- a/drivers/mfd/cs42l43-sdw.c
+++ b/drivers/mfd/cs42l43-sdw.c
@@ -184,6 +184,7 @@ static int cs42l43_sdw_probe(struct sdw_slave *sdw, const struct sdw_device_id *
static const struct sdw_device_id cs42l43_sdw_id[] = {
SDW_SLAVE_ENTRY(0x01FA, 0x4243, (void *)CS42L43_DEVID_VAL),
SDW_SLAVE_ENTRY(0x01FA, 0x2A3B, (void *)CS42L43B_DEVID_VAL),
+ SDW_SLAVE_ENTRY(0x01FA, 0x4244, (void *)CS42L43B_DEVID_VAL),
{ }
};
MODULE_DEVICE_TABLE(sdw, cs42l43_sdw_id);
diff --git a/drivers/mfd/cs42l43.c b/drivers/mfd/cs42l43.c
index 33479ddd539a6..d6027fa4de705 100644
--- a/drivers/mfd/cs42l43.c
+++ b/drivers/mfd/cs42l43.c
@@ -959,6 +959,7 @@ static void cs42l43_boot_work(struct work_struct *work)
{
struct cs42l43 *cs42l43 = container_of(work, struct cs42l43, boot_work);
unsigned int devid, revid, otp;
+ bool valid_id;
int ret;

ret = cs42l43_wait_for_attach(cs42l43);
@@ -973,19 +974,24 @@ static void cs42l43_boot_work(struct work_struct *work)

switch (devid) {
case CS42L43_DEVID_VAL:
+ valid_id = (cs42l43->variant_id == CS42L43_DEVID_VAL);
+ break;
case CS42L43B_DEVID_VAL:
- if (devid != cs42l43->variant_id) {
- dev_err(cs42l43->dev,
- "Device ID (0x%06x) does not match variant ID (0x%06lx)\n",
- devid, cs42l43->variant_id);
- goto err;
- }
+ case CS42L44_DEVID_VAL:
+ valid_id = (cs42l43->variant_id == CS42L43B_DEVID_VAL);
break;
default:
dev_err(cs42l43->dev, "Unrecognised devid: 0x%06x\n", devid);
goto err;
}

+ if (!valid_id) {
+ dev_err(cs42l43->dev,
+ "Device ID (0x%06x) does not match variant ID (0x%06lx)\n",
+ devid, cs42l43->variant_id);
+ goto err;
+ }
+
ret = regmap_read(cs42l43->regmap, CS42L43_REVID, &revid);
if (ret) {
dev_err(cs42l43->dev, "Failed to read rev: %d\n", ret);
diff --git a/include/linux/mfd/cs42l43-regs.h b/include/linux/mfd/cs42l43-regs.h
index 68831f113589d..4c00ceae8b461 100644
--- a/include/linux/mfd/cs42l43-regs.h
+++ b/include/linux/mfd/cs42l43-regs.h
@@ -1183,6 +1183,7 @@

/* CS42L43B VARIANT REGISTERS */
#define CS42L43B_DEVID_VAL 0x0042A43B
+#define CS42L44_DEVID_VAL 0x00042A44

#define CS42L43B_DECIM_VOL_CTRL_CH1_CH2 0x00008280
#define CS42L43B_DECIM_VOL_CTRL_CH3_CH4 0x00008284
--
2.47.3