Commit cc6d5a8c authored by Mark Brown's avatar Mark Brown
Browse files

ASoC: wm8994: VMID management improvements 



Raise the ramp time to 50ms to cover corner cases, use the startup bias
generator, explicitly reset the ramp circuit when complete and reorder
things all of which should improve performance somewhat for systems that
are sensitive to noise from VMID.

Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent d60d6c3b

sound/soc/codecs/wm8994.c

+14 −6
Original line number Diff line number Diff line
@@ -778,29 +778,37 @@ static void vmid_reference(struct snd_soc_codec *codec) 
		wm8994->vmid_refcount);



	if (wm8994->vmid_refcount == 1) {

		snd_soc_update_bits(codec, WM8994_ANTIPOP_1,

				    WM8994_LINEOUT_VMID_BUF_ENA |

				    WM8994_LINEOUT1_DISCH |

				    WM8994_LINEOUT2_DISCH,

				    WM8994_LINEOUT_VMID_BUF_ENA);



		/* Startup bias, VMID ramp & buffer */

		snd_soc_update_bits(codec, WM8994_ANTIPOP_2,

				    WM8994_BIAS_SRC |

				    WM8994_VMID_DISCH |

				    WM8994_STARTUP_BIAS_ENA |

				    WM8994_VMID_BUF_ENA |

				    WM8994_VMID_RAMP_MASK,

				    WM8994_BIAS_SRC |

				    WM8994_STARTUP_BIAS_ENA |

				    WM8994_VMID_BUF_ENA |

				    (0x3 << WM8994_VMID_RAMP_SHIFT));



		wm_hubs_vmid_ena(codec);



		/* Remove discharge for line out */

		snd_soc_update_bits(codec, WM8994_ANTIPOP_1,

				    WM8994_LINEOUT1_DISCH |

				    WM8994_LINEOUT2_DISCH, 0);



		/* Main bias enable, VMID=2x40k */

		snd_soc_update_bits(codec, WM8994_POWER_MANAGEMENT_1,

				    WM8994_BIAS_ENA |

				    WM8994_VMID_SEL_MASK,

				    WM8994_BIAS_ENA | 0x2);



		msleep(20);

		msleep(50);



		snd_soc_update_bits(codec, WM8994_ANTIPOP_2,

				    WM8994_VMID_RAMP_MASK | WM8994_BIAS_SRC,

				    0);

	}

}

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