Hi Russell, On 22/02/2019 16.35, Russell King - ARM Linux admin wrote: > On Fri, Feb 22, 2019 at 03:47:14PM +0200, Peter Ujfalusi wrote: >> Hi, >> >> the original version was sent 14.04.2018: >> https://patchwork.kernel.org/patch/10344403/ >> >> Changes since then: >> - rebased on currentl drm/next >> >> The reset value of the register is 0, the soft reset does not reset this >> register and if other kernel changed this the audio is going to be >> distorted. >> >> It was observed when - accidentally - booted the kernel from eMMC on BBB >> which is 3.8.13-bone79 and it sets this register to 0x0a. After reboot and >> tda998x_reset() it remains 0x0a. > > Have you checked whether the input I2S stream is Philips or Left > Justified? This is controlled by the LSB two bits.
The am335x-boneblack-common.dtsi configures the link to i2s, which corresponds to Philips format (the default > > It appears that 3.8.13-bone79 configures the TDA998x for left- > justified, whereas re-setting these two bits to zero will configure > it for Philips. The chip reset value for the register is 0 and software reset will not reset it if it was modified. > Bits 3:2 control the data size, but I have no information what their > values correspond to. I can not find the register descriptions, can not tell what are the bits in there. > Can we nail down what is required for BBB and what it doesn't care > about. atm the REG_I2S_FORMAT register needs to be reset to 0. > and I think we should implement at least setting the I2S > register format from the hdmi_codec_daifmt data. Yes, that needs to be done for sure, but without data sheet with register descriptions I would not attempt to do that. > It would also be good to know what Fs value(s) BBB uses, and what > sample sizes you have tested. On BBB McASP is the clock master and as I recall I have tested 44.1, 48 KHz at least with 16 and 24 bits. >> >> Signed-off-by: Peter Ujfalusi <peter.ujfal...@ti.com> >> --- >> drivers/gpu/drm/i2c/tda998x_drv.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c >> b/drivers/gpu/drm/i2c/tda998x_drv.c >> index 7f34601bb515..72f93802d209 100644 >> --- a/drivers/gpu/drm/i2c/tda998x_drv.c >> +++ b/drivers/gpu/drm/i2c/tda998x_drv.c >> @@ -722,6 +722,9 @@ tda998x_reset(struct tda998x_priv *priv) >> >> /* Write the default value MUX register */ >> reg_write(priv, REG_MUX_VP_VIP_OUT, 0x24); >> + >> + /* Write the default to I2S_FORMAT register */ >> + reg_write(priv, REG_I2S_FORMAT, 0x00); >> } >> >> /* >> -- >> Peter >> >> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. >> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki >> >> > - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
