Re: [PATCH 2/2] ASoC: Adds support for TAS575x to the pcm512x driver

On Thu, Sep 07, 2023 at 06:12:05PM +0200, Joerg Schambacher wrote:

• if (pcm512x->tas_device) {
  

• 	/* set necessary PLL coeffs for amp
  

• 	 * according to spec only 2x and 4x MCLKs
  

• 	 * possible
  

• 	 */
  

• 	ret = regmap_write(pcm512x->regmap,
  

• 			   PCM512x_PLL_COEFF_0, 0x01);
  

• 	if (mck_rate > 25000000UL)
  

• 		ret = regmap_write(pcm512x->regmap,
  

• 				   PCM512x_PLL_COEFF_1, 0x02);
  

• 	else
  

• 		ret = regmap_write(pcm512x->regmap,
  

• 				   PCM512x_PLL_COEFF_1, 0x04);
  

I would name this quirk something a bit more specific - it seems likely that there might be future TASxxxx devices which need different quirks. If it's a limited range of MCLK multipliers perhaps something about how the PLL is limited, or just make the quirk data being to specify min/max for the multiplier?

• if (!pcm512x->tas_device) {
  

• 	ret = regmap_update_bits(pcm512x->regmap,
  

• 				 PCM512x_PLL_EN, PCM512x_PLLE, 0);
  

• } else {
  

• 	/* leave PLL enabled for amp clocking */
  

• 	ret = regmap_write(pcm512x->regmap,
  

• 			   PCM512x_PLL_EN, 0x01);
  

• 	dev_dbg(component->dev, "Enabling PLL for TAS575x\n");
  

• }
  

This is probably a separate quirk? I'm a bit concerned about what's turning the PLL off here...