firmware: cs_dsp: Add pre_stop callback

The code already has a post_stop callback, add a matching pre_stop
callback to the client_ops that is called before execution is stopped.
This callback provides a convenient place for the client code to
communicate with the DSP before it is stopped.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220722094851.92521-1-ckeepax@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/firmware/cirrus/cs_dsp.c

@@ -2725,6 +2725,9 @@ void cs_dsp_stop(struct cs_dsp *dsp)
 
 	mutex_lock(&dsp->pwr_lock);
 
+	if (dsp->client_ops->pre_stop)
+		dsp->client_ops->pre_stop(dsp);
+
 	dsp->running = false;
 
 	if (dsp->ops->stop_core)

include/linux/firmware/cirrus/cs_dsp.h

@@ -189,7 +189,8 @@ struct cs_dsp {
  * @control_remove:	Called under the pwr_lock when a control is destroyed
  * @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()
+ * @pre_stop:		Called under the pwr_lock by cs_dsp_stop() before the core is stopped
+ * @post_stop:		Called under the pwr_lock by cs_dsp_stop() after the core is stopped
  * @watchdog_expired:	Called when a watchdog expiry is detected
  *
  * These callbacks give the cs_dsp client an opportunity to respond to events
@@ -200,6 +201,7 @@ struct cs_dsp_client_ops {
 	void (*control_remove)(struct cs_dsp_coeff_ctl *ctl);
 	int (*pre_run)(struct cs_dsp *dsp);
 	int (*post_run)(struct cs_dsp *dsp);
+	void (*pre_stop)(struct cs_dsp *dsp);
 	void (*post_stop)(struct cs_dsp *dsp);
 	void (*watchdog_expired)(struct cs_dsp *dsp);
 };