drivers: audio: dmic_mcux: remove arbitrary mapping of pdm to dmic channel (1f69b91e) · Commits · Wenxi XU / zephyr

The dmic_mcux driver required a mapping of paired dmics to specify the same pdm number, and would arbitrarily assign the left channel of the pair to even dmic channel number and the right to an odd dmic channel number. Change this so that the pdm number in the mapping is used as the dmic channel number, and paired dmics are checked to specify consecutive pdm numbers (instead of the same pdm number). This allows users to control explicitly which dmic channel to use and whether that dmic channel is left or right, without this arbitrary indirect mapping. This is important in case they want a dmic that is wired to be right channel to be assigned to dmic channel 0, which is the only channel that supports hwvad. Signed-off-by:

Mike J. Chen <mjchen@google.com>

drivers/audio/dmic_mcux.c

+4 −11

Original line number	Diff line number	Diff line
		@@ -67,18 +67,11 @@ static uint8_t dmic_mcux_hw_chan(struct mcux_dmic_drv_data *drv_data,
		enum pdm_lr lr;
		uint8_t hw_chan;

		/* This function assigns hardware channel "n" to the left channel,
		* and hardware channel "n+1" to the right channel. This choice is
		* arbitrary, but must be followed throughout the driver.
		*/
		dmic_parse_channel_map(drv_data->chan_map_lo,
		drv_data->chan_map_hi,
		log_chan, &hw_chan, &lr);
		if (lr == PDM_CHAN_LEFT) {
		return hw_chan * 2;
		} else {
		return (hw_chan * 2) + 1;
		}

		return hw_chan;
		}

		static void dmic_mcux_activate_channels(struct mcux_dmic_drv_data *drv_data,
		@@ -501,9 +494,9 @@ static int dmic_mcux_configure(const struct device *dev,
		dmic_parse_channel_map(channel->req_chan_map_lo,
		channel->req_chan_map_hi,
		chan + 1, &hw_chan_1, &lr_1);
		/* Verify that paired channels use same hardware index */
		/* Verify that paired channels use consecutive hardware index */
		if ((lr_0 == lr_1) \|\|
		(hw_chan_0 != hw_chan_1)) {
		(hw_chan_1 != (hw_chan_0 + 1))) {
		return -EINVAL;
		}
		}

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