ALSA: hda/cs35l56: Create debugfs files for factory calibration

Create debugfs files that can be used to perform factory calibration.

During manufacture, the production line must perform a factory calibration
of the amps. This commit adds this functionality via debugfs files.

As this is only needed during manufacture, there is no need for this to be
available in a normal system so a Kconfig item has been added to enable
this. The new Kconfig option is inside a sub-menu because items do not
group and indent if the parent is invisible or there are multiple parent
dependencies. Anyway the sub-menu reduces the clutter.

cs35l56_hda_apply_calibration() has been changed to return an error code
that can be reported back through the debugfs write. The original call to
this function doesn't check the return code because in normal use it
doesn't matter whether this fails - the firmware will default to a safe
calibration for the platform. But tooling using the debugfs files might
want to know if there was an error.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251021105022.1013685-6-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/hda/codecs/side-codecs/Kconfig

@@ -88,6 +88,21 @@ config SND_HDA_SCODEC_CS35L56_SPI
 	  Say Y or M here to include CS35L56 amplifier support with
 	  SPI control.
 
+menu "CS35L56 driver options"
+	depends on SND_HDA_SCODEC_CS35L56
+
+config SND_HDA_SCODEC_CS35L56_CAL_DEBUGFS
+	bool "CS35L56 create debugfs for factory calibration"
+	default N
+	depends on DEBUG_FS
+	select SND_SOC_CS35L56_CAL_DEBUGFS_COMMON
+	help
+	  Create debugfs entries used during factory-line manufacture
+	  for factory calibration.
+
+	  If unsure select "N".
+endmenu
+
 config SND_HDA_SCODEC_TAS2781
 	tristate
 	select SND_HDA_GENERIC

sound/hda/codecs/side-codecs/cs35l56_hda.c

@@ -548,20 +548,24 @@ static void cs35l56_hda_release_firmware_files(const struct firmware *wmfw_firmw
 	kfree(coeff_filename);
 }
 
-static void cs35l56_hda_apply_calibration(struct cs35l56_hda *cs35l56)
+static int cs35l56_hda_apply_calibration(struct cs35l56_hda *cs35l56)
 {
 	int ret;
 
 	if (!cs35l56->base.cal_data_valid || cs35l56->base.secured)
-		return;
+		return -EACCES;
 
 	ret = cs_amp_write_cal_coeffs(&cs35l56->cs_dsp,
 				      &cs35l56_calibration_controls,
 				      &cs35l56->base.cal_data);
-	if (ret < 0)
+	if (ret < 0) {
 		dev_warn(cs35l56->base.dev, "Failed to write calibration: %d\n", ret);
-	else
-		dev_info(cs35l56->base.dev, "Calibration applied\n");
+		return ret;
+	}
+
+	dev_info(cs35l56->base.dev, "Calibration applied\n");
+
+	return 0;
 }
 
 static void cs35l56_hda_fw_load(struct cs35l56_hda *cs35l56)
@@ -669,7 +673,9 @@ static void cs35l56_hda_fw_load(struct cs35l56_hda *cs35l56)
 	if (ret)
 		dev_dbg(cs35l56->base.dev, "%s: cs_dsp_run ret %d\n", __func__, ret);
 
+	/* Don't need to check return code, it's not fatal if this fails */
 	cs35l56_hda_apply_calibration(cs35l56);
+
 	ret = cs35l56_mbox_send(&cs35l56->base, CS35L56_MBOX_CMD_AUDIO_REINIT);
 	if (ret)
 		cs_dsp_stop(&cs35l56->cs_dsp);
@@ -695,6 +701,100 @@ static void cs35l56_hda_dsp_work(struct work_struct *work)
 	cs35l56_hda_fw_load(cs35l56);
 }
 
+static ssize_t cs35l56_hda_debugfs_calibrate_write(struct file *file,
+						   const char __user *from,
+						   size_t count, loff_t *ppos)
+{
+	struct cs35l56_base *cs35l56_base = file->private_data;
+	ssize_t ret;
+
+	ret = pm_runtime_resume_and_get(cs35l56_base->dev);
+	if (ret)
+		return ret;
+
+	ret = cs35l56_calibrate_debugfs_write(cs35l56_base, from, count, ppos);
+	pm_runtime_autosuspend(cs35l56_base->dev);
+
+	return ret;
+}
+
+static ssize_t cs35l56_hda_debugfs_cal_temperature_write(struct file *file,
+							 const char __user *from,
+							 size_t count, loff_t *ppos)
+{
+	struct cs35l56_base *cs35l56_base = file->private_data;
+	ssize_t ret;
+
+	ret = pm_runtime_resume_and_get(cs35l56_base->dev);
+	if (ret)
+		return ret;
+
+	ret = cs35l56_cal_ambient_debugfs_write(cs35l56_base, from, count, ppos);
+	pm_runtime_autosuspend(cs35l56_base->dev);
+
+	return ret;
+}
+
+static ssize_t cs35l56_hda_debugfs_cal_data_read(struct file *file,
+						 char __user *to,
+						 size_t count, loff_t *ppos)
+{
+	struct cs35l56_base *cs35l56_base = file->private_data;
+	ssize_t ret;
+
+	ret = pm_runtime_resume_and_get(cs35l56_base->dev);
+	if (ret)
+		return ret;
+
+	ret = cs35l56_cal_data_debugfs_read(cs35l56_base, to, count, ppos);
+	pm_runtime_autosuspend(cs35l56_base->dev);
+
+	return ret;
+}
+
+static ssize_t cs35l56_hda_debugfs_cal_data_write(struct file *file,
+						  const char __user *from,
+						  size_t count, loff_t *ppos)
+{
+	struct cs35l56_base *cs35l56_base = file->private_data;
+	struct cs35l56_hda *cs35l56 = cs35l56_hda_from_base(cs35l56_base);
+	ssize_t ret;
+
+	ret = cs35l56_cal_data_debugfs_write(cs35l56_base, from, count, ppos);
+	if (ret == -ENODATA)
+		return count;	/* Ignore writes of empty cal blobs */
+
+	if (ret < 0)
+		return ret;
+
+	ret = pm_runtime_resume_and_get(cs35l56_base->dev);
+	if (ret)
+		return ret;
+
+	ret = cs35l56_hda_apply_calibration(cs35l56);
+	if (ret == 0)
+		cs35l56_mbox_send(cs35l56_base, CS35L56_MBOX_CMD_AUDIO_REINIT);
+	else
+		count = -EIO;
+
+	pm_runtime_autosuspend(cs35l56_base->dev);
+
+	return count;
+}
+
+static const struct cs35l56_cal_debugfs_fops cs35l56_hda_cal_debugfs_fops = {
+	.calibrate = {
+		.write = cs35l56_hda_debugfs_calibrate_write,
+	},
+	.cal_temperature = {
+		.write = cs35l56_hda_debugfs_cal_temperature_write,
+	},
+	.cal_data = {
+		.read = cs35l56_hda_debugfs_cal_data_read,
+		.write = cs35l56_hda_debugfs_cal_data_write,
+	},
+};
+
 static int cs35l56_hda_bind(struct device *dev, struct device *master, void *master_data)
 {
 	struct cs35l56_hda *cs35l56 = dev_get_drvdata(dev);
@@ -722,6 +822,9 @@ static int cs35l56_hda_bind(struct device *dev, struct device *master, void *mas
 	cs_dsp_init_debugfs(&cs35l56->cs_dsp, cs35l56->debugfs_root);
 #endif
 
+	if (IS_ENABLED(CONFIG_SND_HDA_SCODEC_CS35L56_CAL_DEBUGFS))
+		cs35l56_create_cal_debugfs(&cs35l56->base, &cs35l56_hda_cal_debugfs_fops);
+
 	dev_dbg(cs35l56->base.dev, "Bound\n");
 
 	return 0;
@@ -735,6 +838,7 @@ static void cs35l56_hda_unbind(struct device *dev, struct device *master, void *
 
 	cancel_work_sync(&cs35l56->dsp_work);
 
+	cs35l56_remove_cal_debugfs(&cs35l56->base);
 	cs35l56_hda_remove_controls(cs35l56);
 
 #if IS_ENABLED(CONFIG_SND_DEBUG)

sound/hda/codecs/side-codecs/cs35l56_hda.h

@@ -9,6 +9,7 @@
 #ifndef __CS35L56_HDA_H__
 #define __CS35L56_HDA_H__
 
+#include <linux/container_of.h>
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/firmware/cirrus/cs_dsp.h>
@@ -42,6 +43,11 @@ struct cs35l56_hda {
 #endif
 };
 
+static inline struct cs35l56_hda *cs35l56_hda_from_base(struct cs35l56_base *cs35l56_base)
+{
+	return container_of(cs35l56_base, struct cs35l56_hda, base);
+}
+
 extern const struct dev_pm_ops cs35l56_hda_pm_ops;
 
 int cs35l56_hda_common_probe(struct cs35l56_hda *cs35l56, int hid, int id);