Re: [PATCH v1 4/4] ASoC: tda7802: Add speaker-test sysfs

From: Cezary Rojewski
Date: Wed Jun 12 2019 - 14:01:29 EST


On 2019-06-11 19:49, Thomas Preston wrote:
Add speaker_test device attribute. When the speaker-test node is read
the hardware speaker test is started.

$ cat /sys/devices/.../device:00/speaker_test
04 04 04 04

Signed-off-by: Thomas Preston <thomas.preston@xxxxxxxxxxxxxxx>
Cc: Patrick Glaser <pglaser@xxxxxxxxx>
Cc: Rob Duncan <rduncan@xxxxxxxxx>
Cc: Nate Case <ncase@xxxxxxxxx>
---
sound/soc/codecs/tda7802.c | 172 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 172 insertions(+)

diff --git a/sound/soc/codecs/tda7802.c b/sound/soc/codecs/tda7802.c
index 62aae011d9f1..edfa752c0c9f 100644
--- a/sound/soc/codecs/tda7802.c
+++ b/sound/soc/codecs/tda7802.c
@@ -157,6 +157,7 @@ static const u8 IB3_FORMAT[4][4] = {
#define DUMP_NUM_REGS (DUMP_NUM_BLOCK * 2)
struct tda7802_priv {
+ struct mutex mutex;
struct i2c_client *i2c;
struct regmap *regmap;
struct regulator *enable_reg;
@@ -458,6 +459,159 @@ static struct snd_soc_dai_driver tda7802_dai_driver = {
.ops = &tda7802_dai_ops,
};
+/* The speaker test is triggered by reading a sysfs attribute file attached to
+ * the I2C device. The user space thread that's doing the reading is blocked
+ * until the test completes (or times out). We only permit one test to be in
+ * progress at a time.
+ */
+
+static int speaker_test_start(struct regmap *regmap)
+{
+ int err;
+
+ err = regmap_update_bits(regmap, TDA7802_IB5, IB5_AMPLIFIER_ON, 0);
+ if (err < 0) {
+ dev_err(regmap_get_device(regmap),
+ "Cannot disable amp for speaker test (%d)\n", err);
+ return err;
+ }
+
+ err = regmap_update_bits(regmap, TDA7802_IB4, IB4_DIAG_MODE_ENABLE, 0);
+ if (err < 0) {
+ dev_err(regmap_get_device(regmap),
+ "Cannot disable diag mode before speaker test (%d)\n",
+ err);
+ return err;
+ }
+
+ /* Seem to need at least a 15 ms delay here before the rising
+ * edge. Otherwise the diagnostics never complete (perhaps
+ * they never start).
+ */
+ msleep(20);
+
+ err = regmap_update_bits(regmap, TDA7802_IB4,
+ IB4_DIAG_MODE_ENABLE, IB4_DIAG_MODE_ENABLE);
+ if (err < 0) {
+ dev_err(regmap_get_device(regmap),
+ "Cannot enable diag mode for speaker test (%d)\n", err);
+ return err;
+ }
+
+ return 0;

You may want to follow path set by speaker_test_stop: replace "return 0" with "return err" and have only error msg found within preceding if-statement.

+}
+
+static int speaker_test_stop(struct regmap *regmap)
+{
+ int err;
+
+ err = regmap_update_bits(regmap, TDA7802_IB4, IB4_DIAG_MODE_ENABLE, 0);
+ if (err < 0)
+ dev_err(regmap_get_device(regmap),
+ "Cannot disable diag mode after speaker test (%d)\n",
+ err);
+ return err;
+}
+
+/* We poll the test completion bit, letting the current thread sleep
+ * until we're done. These values are not critical.
+ */
+#define SPEAKER_TEST_DONE_POLL_PERIOD_US 5000
+#define SPEAKER_TEST_DONE_TIMEOUT_US 5000000
+
+static int speaker_test_check(struct tda7802_priv *tda7802,
+ unsigned int *status)
+{
+ struct regmap *regmap = tda7802->regmap;
+ struct device *dev = &tda7802->i2c->dev;
+ int reg_err = 0, err = 0, i, amp_on;

Both reg_err and err are initialized unnecessarily.

+ unsigned int val;
+
+ reg_err = regulator_enable(tda7802->enable_reg);
+ if (reg_err < 0) {
+ dev_err(dev, "Could not enable (speaker-test).\n");
+ return reg_err;
+ }
+ msleep(ENABLE_DELAY_MS);
+
+ /* we should return amp on state when speaker-test is done */
+ err = regmap_read(regmap, TDA7802_IB5, &amp_on);
+ if (err < 0) {
+ dev_err(dev, "Could not read amp on state (speaker-test)\n");
+ goto speaker_test_disable;
+ }
+
+ for (i = 0; i < CHANNELS_PER_AMP; ++i)
+ status[i] = 0xff;
+
+ err = speaker_test_start(regmap);
+ if (err < 0)
+ goto speaker_test_restore;
+
+ /* Wait until DB0_STARTUP_DIAG_STATUS is set */
+ err = regmap_read_poll_timeout(regmap, TDA7802_DB0, val,
+ val & DB0_STARTUP_DIAG_STATUS,
+ SPEAKER_TEST_DONE_POLL_PERIOD_US,
+ SPEAKER_TEST_DONE_TIMEOUT_US);
+ if (err < 0) {
+ if (err == -ENODATA)
+ dev_err(dev,
+ "Speaker diagnostic test did not complete\n");
+ speaker_test_stop(regmap);
+ goto speaker_test_restore;
+ }
+
+ err = speaker_test_stop(regmap);
+ if (err < 0)
+ goto speaker_test_restore;

This sequence looks weird and as if it could be simplified but I might be just plain wrong. speaker_test_stop gets invoked whether or not regmap_read_poll_timeout fails, though only in "happy" path its return is account for. If it's not too much to ask, could you clarify?

+
+ for (i = 0; i < CHANNELS_PER_AMP; ++i) {
+ err = regmap_read(regmap, TDA7802_DB1 + i, status + i);
+ if (err < 0) {
+ dev_err(dev,
+ "Cannot get speaker %d status (%d)\n", i, err);
+ goto speaker_test_restore;
+ }
+ }
+
+speaker_test_restore:
+ err = regmap_update_bits(regmap, TDA7802_IB5, IB5_AMPLIFIER_ON,
+ amp_on);
+ if (err < 0)
+ dev_err(dev, "Could not restore amp on state (speaker-test)\n");
+
+speaker_test_disable:
+ reg_err = regulator_disable(tda7802->enable_reg);
+ if (reg_err < 0) {
+ dev_err(dev, "Could not disable (speaker-test).\n");
+ return reg_err;
+ }
+ return err;
+}
+
+static ssize_t speaker_test_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tda7802_priv *tda7802 = dev_get_drvdata(dev);
+ unsigned int channel_status[CHANNELS_PER_AMP];
+ char *str = buf;
+ int ret, i;
+
+ mutex_lock(&tda7802->mutex);
+ ret = speaker_test_check(tda7802, channel_status);
+ mutex_unlock(&tda7802->mutex);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < CHANNELS_PER_AMP; i++)
+ str += sprintf(str, "%02x ", channel_status[i]);
+ str += sprintf(str, "\n");
+
+ return str - buf;
+}
+
+static DEVICE_ATTR_RO(speaker_test);
+
static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -537,12 +691,28 @@ static int tda7802_probe(struct snd_soc_component *component)
dev_dbg(dev, "%s\n", __func__);
+ /* Device is ready, now we should create sysfs attributes.
+ * Rememer to cleanup
+ */
err = device_create_file(dev, &dev_attr_enable);
if (err < 0) {
dev_err(dev, "Could not create enable attr\n");
return err;
}
+ mutex_init(&tda7802->mutex);
+ err = device_create_file(dev, &dev_attr_speaker_test);
+ if (err < 0) {
+ dev_err(dev, "Could not create speaker_test attr\n");
+ goto cleanup_speaker_test;
+ }
+
+ return 0;
+
+cleanup_speaker_test:
+ mutex_destroy(&tda7802->mutex);
+ device_remove_file(&tda7802->i2c->dev, &dev_attr_enable);
+
return err;
}
@@ -550,6 +720,8 @@ static void tda7802_remove(struct snd_soc_component *component)
{
struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component);
+ device_remove_file(&tda7802->i2c->dev, &dev_attr_speaker_test);
+ mutex_destroy(&tda7802->mutex);
device_remove_file(&tda7802->i2c->dev, &dev_attr_enable);
}