| Message ID | 20190210154519.2506-1-ps.report@gmx.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,v1] tlv320aic32x4: delay i2c access by 1 ms after hardware reset | expand |
On Sun, Feb 10, 2019 at 04:45:19PM +0100, Peter Seiderer wrote: > @@ -972,6 +972,8 @@ static int aic32x4_component_probe(struct snd_soc_component *component) > gpio_set_value(aic32x4->rstn_gpio, 1); > } > > + mdelay(1); > + Perhaps only do this if we toggled the GPIO? If the device wasn't in reset then there's no need to wait.
Hello Mark, On Mon, 11 Feb 2019 15:04:25 +0000, Mark Brown <broonie@kernel.org> wrote: > On Sun, Feb 10, 2019 at 04:45:19PM +0100, Peter Seiderer wrote: > > > @@ -972,6 +972,8 @@ static int aic32x4_component_probe(struct snd_soc_component *component) > > gpio_set_value(aic32x4->rstn_gpio, 1); > > } > > > > + mdelay(1); > > + > > Perhaps only do this if we toggled the GPIO? If the device wasn't in > reset then there's no need to wait. You are absolutely right with this, will re-spin the patch with the suggested change, thanks for review... Regards, Peter
diff --git a/sound/soc/codecs/tlv320aic32x4.c b/sound/soc/codecs/tlv320aic32x4.c index e1bfba62fc08..b3beb0ca87c3 100644 --- a/sound/soc/codecs/tlv320aic32x4.c +++ b/sound/soc/codecs/tlv320aic32x4.c @@ -972,6 +972,8 @@ static int aic32x4_component_probe(struct snd_soc_component *component) gpio_set_value(aic32x4->rstn_gpio, 1); } + mdelay(1); + snd_soc_component_write(component, AIC32X4_RESET, 0x01); if (aic32x4->setup)
As stated in 'TLV320AIC3254 Application Reference Guide' ([1]): 3.2 Device Startup Lockout Times After the TLV320AIC3254 initializes through hardware reset at power-up or software reset, the internal registers initialize to default values. This initialization takes place within 1ms after pulling the RESET signal high. During this initialization phase, no register-read or register-write operation should be performed on ADC or DAC coefficient buffers. Also, no block within the codec should be powered up during the initialization phase. [1] http://www.ti.com/lit/an/slaa408a/slaa408a.pdf Signed-off-by: Peter Seiderer <ps.report@gmx.net> --- Note: This came up after the electronic departement took a deeper look at the i2c-bus/vcc/reset pins with a logic analyzer and the documentation because of a vcc/reset timing problem (now fixed on custom board). Not 100% sure if the 1 ms is needed (as restricted to ADC/DAC coefficent and codec block power up). --- sound/soc/codecs/tlv320aic32x4.c | 2 ++ 1 file changed, 2 insertions(+)