firmware: cs_dsp: Add pre_run callback

The code already has a post_run callback, add a matching pre_run
callback to the client_ops that is called before execution is started.
This callback provides a convenient place for the client code to
set DSP controls or hardware that requires configuration before
the DSP core actually starts execution. Note that placing this callback
before cs_dsp_coeff_sync_controls is important to ensure that any
control values are then correctly synced out to the chip.
Co-authored-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20211117132300.1290-4-ckeepax@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/firmware/cirrus/cs_dsp.c

@@ -2627,6 +2627,12 @@ int cs_dsp_run(struct cs_dsp *dsp)
 			goto err;
 	}
 
+	if (dsp->client_ops->pre_run) {
+		ret = dsp->client_ops->pre_run(dsp);
+		if (ret)
+			goto err;
+	}
+
 	/* Sync set controls */
 	ret = cs_dsp_coeff_sync_controls(dsp);
 	if (ret != 0)

include/linux/firmware/cirrus/cs_dsp.h

@@ -187,7 +187,8 @@ struct cs_dsp {
  * struct cs_dsp_client_ops - client callbacks
  * @control_add:	Called under the pwr_lock when a control is created
  * @control_remove:	Called under the pwr_lock when a control is destroyed
- * @post_run:		Called under the pwr_lock by cs_dsp_run()
+ * @pre_run:		Called under the pwr_lock by cs_dsp_run() before the core is started
+ * @post_run:		Called under the pwr_lock by cs_dsp_run() after the core is started
  * @post_stop:		Called under the pwr_lock by cs_dsp_stop()
  * @watchdog_expired:	Called when a watchdog expiry is detected
  *
@@ -197,6 +198,7 @@ struct cs_dsp {
 struct cs_dsp_client_ops {
 	int (*control_add)(struct cs_dsp_coeff_ctl *ctl);
 	void (*control_remove)(struct cs_dsp_coeff_ctl *ctl);
+	int (*pre_run)(struct cs_dsp *dsp);
 	int (*post_run)(struct cs_dsp *dsp);
 	void (*post_stop)(struct cs_dsp *dsp);
 	void (*watchdog_expired)(struct cs_dsp *dsp);