[PATCH 01/11] ASoC: cs35l56: Read silicon ID during initialization and save it

Richard Fitzgerald
2025-10-16T10:43:07Z

Read the silicon ID from the amp during one-time cs35l56_hw_init()
and store it in struct cs35l56_base, instead of reading it from
registers every time it is needed.

Note that marking it non-volatile without a default in regmap isn't
a suitable alternative because this causes regcache_sync() to always
write the cached value out to the registers. This could trigger a bus
fault interrupt inside the amp, which we want to avoid.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
include/sound/cs35l56.h | 1 +
sound/soc/codecs/cs35l56-shared.c | 53 +++++++++++++++----------------
2 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h
index ab044ce2aa8b..ec9b1072d6be 100644
--- a/include/sound/cs35l56.h
+++ b/include/sound/cs35l56.h
@@ -309,6 +309,7 @@ struct cs35l56_base {
struct cs35l56_spi_payload *spi_payload_buf;
const struct cs35l56_fw_reg *fw_reg;
const struct cirrus_amp_cal_controls *calibration_controls;
+ u64 silicon_uid;
};

static inline bool cs35l56_is_otp_register(unsigned int reg)
diff --git a/sound/soc/codecs/cs35l56-shared.c b/sound/soc/codecs/cs35l56-shared.c
index 9e6b9ca2f354..1ecfc38d8eb4 100644
--- a/sound/soc/codecs/cs35l56-shared.c
+++ b/sound/soc/codecs/cs35l56-shared.c
@@ -853,7 +853,7 @@ struct cs35l56_pte {
} __packed;
static_assert((sizeof(struct cs35l56_pte) % sizeof(u32)) == 0);

-static int cs35l56_read_silicon_uid(struct cs35l56_base *cs35l56_base, u64 *uid)
+static int cs35l56_read_silicon_uid(struct cs35l56_base *cs35l56_base)
{
struct cs35l56_pte pte;
u64 unique_id;
@@ -870,14 +870,15 @@ static int cs35l56_read_silicon_uid(struct cs35l56_base *cs35l56_base, u64 *uid)
unique_id |= (u32)pte.x | ((u32)pte.y << 8) | ((u32)pte.wafer_id << 16) |
((u32)pte.dvs << 24);

- *uid = unique_id;
+ cs35l56_base->silicon_uid = unique_id;

return 0;
}

-static int cs35l63_read_silicon_uid(struct cs35l56_base *cs35l56_base, u64 *uid)
+static int cs35l63_read_silicon_uid(struct cs35l56_base *cs35l56_base)
{
u32 tmp[2];
+ u64 unique_id;
int ret;

ret = regmap_bulk_read(cs35l56_base->regmap, CS35L56_DIE_STS1, tmp, ARRAY_SIZE(tmp));
@@ -886,9 +887,11 @@ static int cs35l63_read_silicon_uid(struct cs35l56_base *cs35l56_base, u64 *uid)
return ret;
}

- *uid = tmp[1];
- *uid <<= 32;
- *uid |= tmp[0];
+ unique_id = tmp[1];
+ unique_id <<= 32;
+ unique_id |= tmp[0];
+
+ cs35l56_base->silicon_uid = unique_id;

return 0;
}
@@ -915,33 +918,14 @@ static const struct cirrus_amp_cal_controls cs35l63_calibration_controls = {

int cs35l56_get_calibration(struct cs35l56_base *cs35l56_base)
{
- u64 silicon_uid = 0;
int ret;

/* Driver can't apply calibration to a secured part, so skip */
if (cs35l56_base->secured)
return 0;

- switch (cs35l56_base->type) {
- case 0x54:
- case 0x56:
- case 0x57:
- ret = cs35l56_read_silicon_uid(cs35l56_base, &silicon_uid);
- break;
- case 0x63:
- ret = cs35l63_read_silicon_uid(cs35l56_base, &silicon_uid);
- break;
- default:
- ret = -ENODEV;
- break;
- }
-
- if (ret < 0)
- return ret;
-
- dev_dbg(cs35l56_base->dev, "UniqueID = %#llx\n", silicon_uid);
-
- ret = cs_amp_get_efi_calibration_data(cs35l56_base->dev, silicon_uid,
+ ret = cs_amp_get_efi_calibration_data(cs35l56_base->dev,
+ cs35l56_base->silicon_uid,
cs35l56_base->cal_index,
&cs35l56_base->cal_data);

@@ -1111,6 +1095,21 @@ int cs35l56_hw_init(struct cs35l56_base *cs35l56_base)
CS35L56_TEMP_ERR_EINT1_MASK,
0);

+ switch (cs35l56_base->type) {
+ case 0x54:
+ case 0x56:
+ case 0x57:
+ ret = cs35l56_read_silicon_uid(cs35l56_base);
+ break;
+ default:
+ ret = cs35l63_read_silicon_uid(cs35l56_base);
+ break;
+ }
+ if (ret)
+ return ret;
+
+ dev_dbg(cs35l56_base->dev, "SiliconID = %#llx\n", cs35l56_base->silicon_uid);
+
return 0;
}
EXPORT_SYMBOL_NS_GPL(cs35l56_hw_init, "SND_SOC_CS35L56_SHARED");
--
2.47.3