[PATCH 02/11] ASoC: cs-amp-lib: Add helpers for factory calibration

Richard Fitzgerald
2025-10-16T10:42:55Z

Add two helper functions for performing factory calibration.

cs_amp_read_cal_coeffs() reads the results of a calibration into a
struct cirrus_amp_cal_data. The calTime member is also filled in with
the current time (which is defined to be in Windows format).

cs_amp_write_ambient_temp() writes a given temperature value to the
firmware control for ambient temperature.

The cs_amp_cal_target_u64() has been moved into the header file so
that it can be used by the calling code and by KUnit tests.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
include/sound/cs-amp-lib.h | 11 +++
sound/soc/codecs/cs-amp-lib.c | 122 ++++++++++++++++++++++++++++++++--
2 files changed, 128 insertions(+), 5 deletions(-)

diff --git a/include/sound/cs-amp-lib.h b/include/sound/cs-amp-lib.h
index 43a87a39110c..e4df0736039a 100644
--- a/include/sound/cs-amp-lib.h
+++ b/include/sound/cs-amp-lib.h
@@ -47,10 +47,21 @@ struct cirrus_amp_cal_controls {
int cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
const struct cirrus_amp_cal_controls *controls,
const struct cirrus_amp_cal_data *data);
+int cs_amp_read_cal_coeffs(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ struct cirrus_amp_cal_data *data);
+int cs_amp_write_ambient_temp(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ u32 temp);
int cs_amp_get_efi_calibration_data(struct device *dev, u64 target_uid, int amp_index,
struct cirrus_amp_cal_data *out_data);
int cs_amp_get_vendor_spkid(struct device *dev);

+static inline u64 cs_amp_cal_target_u64(const struct cirrus_amp_cal_data *data)
+{
+ return ((u64)data->calTarget[1] << 32) | data->calTarget[0];
+}
+
struct cs_amp_test_hooks {
efi_status_t (*get_efi_variable)(efi_char16_t *name,
efi_guid_t *guid,
diff --git a/sound/soc/codecs/cs-amp-lib.c b/sound/soc/codecs/cs-amp-lib.c
index 8434d5196107..b2509c5c0690 100644
--- a/sound/soc/codecs/cs-amp-lib.c
+++ b/sound/soc/codecs/cs-amp-lib.c
@@ -10,9 +10,11 @@
#include <linux/dev_printk.h>
#include <linux/efi.h>
#include <linux/firmware/cirrus/cs_dsp.h>
+#include <linux/math64.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/slab.h>
+#include <linux/timekeeping.h>
#include <linux/types.h>
#include <sound/cs-amp-lib.h>

@@ -46,6 +48,16 @@ static const struct cs_amp_lib_cal_efivar {
},
};

+/* Offset from Unix time to Windows time (100ns since 1 Jan 1601) */
+#define UNIX_TIME_TO_WINDOWS_TIME_OFFSET 116444736000000000ULL
+
+static u64 cs_amp_time_now_in_windows_time(void)
+{
+ u64 time_in_100ns = div_u64(ktime_get_real_ns(), 100);
+
+ return time_in_100ns + UNIX_TIME_TO_WINDOWS_TIME_OFFSET;
+}
+
static int cs_amp_write_cal_coeff(struct cs_dsp *dsp,
const struct cirrus_amp_cal_controls *controls,
const char *ctl_name, u32 val)
@@ -73,6 +85,34 @@ static int cs_amp_write_cal_coeff(struct cs_dsp *dsp,
return -ENODEV;
}

+static int cs_amp_read_cal_coeff(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ const char *ctl_name, u32 *val)
+{
+ struct cs_dsp_coeff_ctl *cs_ctl;
+ __be32 beval;
+ int ret;
+
+ KUNIT_STATIC_STUB_REDIRECT(cs_amp_read_cal_coeff, dsp, controls, ctl_name, val);
+
+ if (!IS_REACHABLE(CONFIG_FW_CS_DSP))
+ return -ENODEV;
+
+ scoped_guard(mutex, &dsp->pwr_lock) {
+ cs_ctl = cs_dsp_get_ctl(dsp, ctl_name, controls->mem_region, controls->alg_id);
+ ret = cs_dsp_coeff_read_ctrl(cs_ctl, 0, &beval, sizeof(beval));
+ }
+
+ if (ret < 0) {
+ dev_err(dsp->dev, "Failed to write to '%s': %d\n", ctl_name, ret);
+ return ret;
+ }
+
+ *val = be32_to_cpu(beval);
+
+ return 0;
+}
+
static int _cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
const struct cirrus_amp_cal_controls *controls,
const struct cirrus_amp_cal_data *data)
@@ -106,6 +146,45 @@ static int _cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
return 0;
}

+static int _cs_amp_read_cal_coeffs(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ struct cirrus_amp_cal_data *data)
+{
+ u64 time;
+ u32 val;
+ int ret;
+
+ if (list_empty(&dsp->ctl_list)) {
+ dev_info(dsp->dev, "Calibration disabled due to missing firmware controls\n");
+ return -ENOENT;
+ }
+
+ ret = cs_amp_read_cal_coeff(dsp, controls, controls->ambient, &val);
+ if (ret)
+ return ret;
+
+ data->calAmbient = (s8)val;
+
+ ret = cs_amp_read_cal_coeff(dsp, controls, controls->calr, &val);
+ if (ret)
+ return ret;
+
+ data->calR = (u16)val;
+
+ ret = cs_amp_read_cal_coeff(dsp, controls, controls->status, &val);
+ if (ret)
+ return ret;
+
+ data->calStatus = (u8)val;
+
+ /* Fill in timestamp */
+ time = cs_amp_time_now_in_windows_time();
+ data->calTime[0] = (u32)time;
+ data->calTime[1] = (u32)(time >> 32);
+
+ return 0;
+}
+
/**
* cs_amp_write_cal_coeffs - Write calibration data to firmware controls.
* @dsp: Pointer to struct cs_dsp.
@@ -125,6 +204,44 @@ int cs_amp_write_cal_coeffs(struct cs_dsp *dsp,
}
EXPORT_SYMBOL_NS_GPL(cs_amp_write_cal_coeffs, "SND_SOC_CS_AMP_LIB");

+/**
+ * cs_amp_read_cal_coeffs - Read calibration data from firmware controls.
+ * @dsp: Pointer to struct cs_dsp.
+ * @controls: Pointer to definition of firmware controls to be read.
+ * @data: Pointer to calibration data where results will be written.
+ *
+ * Returns: 0 on success, else negative error value.
+ */
+int cs_amp_read_cal_coeffs(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ struct cirrus_amp_cal_data *data)
+{
+ if (IS_REACHABLE(CONFIG_FW_CS_DSP) || IS_ENABLED(CONFIG_SND_SOC_CS_AMP_LIB_TEST))
+ return _cs_amp_read_cal_coeffs(dsp, controls, data);
+ else
+ return -ENODEV;
+}
+EXPORT_SYMBOL_NS_GPL(cs_amp_read_cal_coeffs, "SND_SOC_CS_AMP_LIB");
+
+/**
+ * cs_amp_write_ambient_temp - write value to calibration ambient temperature
+ * @dsp: Pointer to struct cs_dsp.
+ * @controls: Pointer to definition of firmware controls to be read.
+ * @temp: Temperature in degrees celcius.
+ *
+ * Returns: 0 on success, else negative error value.
+ */
+int cs_amp_write_ambient_temp(struct cs_dsp *dsp,
+ const struct cirrus_amp_cal_controls *controls,
+ u32 temp)
+{
+ if (IS_REACHABLE(CONFIG_FW_CS_DSP) || IS_ENABLED(CONFIG_SND_SOC_CS_AMP_LIB_TEST))
+ return cs_amp_write_cal_coeff(dsp, controls, controls->ambient, temp);
+ else
+ return -ENODEV;
+}
+EXPORT_SYMBOL_NS_GPL(cs_amp_write_ambient_temp, "SND_SOC_CS_AMP_LIB");
+
static efi_status_t cs_amp_get_efi_variable(efi_char16_t *name,
efi_guid_t *guid,
unsigned long *size,
@@ -215,11 +332,6 @@ static struct cirrus_amp_efi_data *cs_amp_get_cal_efi_buffer(struct device *dev)
return ERR_PTR(ret);
}

-static u64 cs_amp_cal_target_u64(const struct cirrus_amp_cal_data *data)
-{
- return ((u64)data->calTarget[1] << 32) | data->calTarget[0];
-}
-
static int _cs_amp_get_efi_calibration_data(struct device *dev, u64 target_uid, int amp_index,
struct cirrus_amp_cal_data *out_data)
{
--
2.47.3