Hi, Thanks for getting back to me so quickly. On 30/07/2019 13:41, Charles Keepax wrote: > On Tue, Jul 30, 2019 at 01:09:37PM +0100, Thomas Preston wrote: >> Add a debugfs device node which initiates the turn-on diagnostic routine >> feature of the TDA7802 amplifier. The four status registers (one per >> channel) are returned. >> >> Signed-off-by: Thomas Preston <thomas.preston@xxxxxxxxxxxxxxx> >> --- >> Changes since v1: >> - Rename speaker-test to (turn-on) diagnostics >> - Move turn-on diagnostic to debugfs as there is no standard ALSA >> interface for this kind of routine. >> >> sound/soc/codecs/tda7802.c | 186 ++++++++++++++++++++++++++++++++++++- >> 1 file changed, 185 insertions(+), 1 deletion(-) >> >> +static int tda7802_bulk_update(struct regmap *map, struct reg_update *update, >> + size_t update_count) >> +{ >> + int i, err; >> + >> + for (i = 0; i < update_count; i++) { >> + err = regmap_update_bits(map, update[i].reg, update[i].mask, >> + update[i].val); >> + if (err < 0) >> + return err; >> + } >> + >> + return i; >> +} > > This could probably be removed using regmap_multi_reg_write. > The problem is that I want to retain the state of the other bits in those registers. Maybe I should make a copy of the backed up state, set the bits I want to off-device, then either: 1. Write the changes with regmap_multi_reg_write 2. Write all six regs again (if my device doesn't support the multi_reg) >> +static int tda7802_probe(struct snd_soc_component *component) >> +{ >> + struct tda7802_priv *tda7802 = snd_soc_component_get_drvdata(component); >> + struct device *dev = &tda7802->i2c->dev; >> + int err; >> + >> + tda7802->debugfs = debugfs_create_dir(dev_name(dev), NULL); >> + if (IS_ERR_OR_NULL(tda7802->debugfs)) { >> + dev_info(dev, >> + "Failed to create debugfs node, err %ld\n", >> + PTR_ERR(tda7802->debugfs)); >> + return 0; >> + } >> + >> + mutex_init(&tda7802->diagnostic_mutex); >> + err = debugfs_create_file("diagnostic", 0444, tda7802->debugfs, tda7802, >> + &tda7802_diagnostic_fops); >> + if (err < 0) { >> + dev_err(dev, >> + "debugfs: Failed to create diagnostic node, err %d\n", >> + err); >> + goto cleanup_diagnostic; >> + } > > You shouldn't be failing the driver probe if debugfs fails, it > should be purely optional. > Got it, thanks.