ASoC: rockchip: i2s-tdm: Use param rate if not provided by set_sysclk

Drivers will not always call set_sysclk() for all clocks, especially when
default mclk-fs can be used.
When that is the case, use the clock rate set in the params multiplied by the
default mclk-fs.

Fixes: 5323186 ("ASoC: rockchip: i2s_tdm: Re-add the set_sysclk callback")
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Reported-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patch.msgid.link/20260218201834.924358-1-detlev.casanova@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: cazou

sound/soc/rockchip/rockchip_i2s_tdm.c

@@ -22,6 +22,7 @@
 
 #define DRV_NAME "rockchip-i2s-tdm"
 
+#define DEFAULT_MCLK_FS				256
 #define CH_GRP_MAX				4  /* The max channel 8 / 2 */
 #define MULTIPLEX_CH_MAX			10
 
@@ -665,6 +666,15 @@ static int rockchip_i2s_tdm_hw_params(struct snd_pcm_substream *substream,
 			mclk_rate = i2s_tdm->mclk_rx_freq;
 		}
 
+		/*
+		 * When the dai/component driver doesn't need to set mclk-fs for a specific
+		 * clock, it can skip the call to set_sysclk() for that clock.
+		 * In that case, simply use the clock rate from the params and multiply it by
+		 * the default mclk-fs value.
+		 */
+		if (!mclk_rate)
+			mclk_rate = DEFAULT_MCLK_FS * params_rate(params);
+
 		err = clk_set_rate(mclk, mclk_rate);
 		if (err)
 			return err;