ASoC: wm_adsp: Support powering-up DSP without trying to load firmware

Add a flag to wm_adsp_power_up() that indicates whether it should attempt
to find and load firmware files.

This is to support DSPs that have built-in firmware that may already have
been patched (for example, by the BIOS). In that case the patch must not
be overwritten because that could corrupt the running firmware.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230815124826.5447-2-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs35l56.c

@@ -656,7 +656,7 @@ static void cs35l56_secure_patch(struct cs35l56_private *cs35l56)
 	int ret;
 
 	/* Use wm_adsp to load and apply the firmware patch and coefficient files */
-	ret = wm_adsp_power_up(&cs35l56->dsp);
+	ret = wm_adsp_power_up(&cs35l56->dsp, true);
 	if (ret)
 		dev_dbg(cs35l56->base.dev, "%s: wm_adsp_power_up ret %d\n", __func__, ret);
 	else
@@ -686,7 +686,7 @@ static void cs35l56_patch(struct cs35l56_private *cs35l56)
 		goto err;
 
 	/* Use wm_adsp to load and apply the firmware patch and coefficient files */
-	ret = wm_adsp_power_up(&cs35l56->dsp);
+	ret = wm_adsp_power_up(&cs35l56->dsp, true);
 	if (ret) {
 		dev_dbg(cs35l56->base.dev, "%s: wm_adsp_power_up ret %d\n", __func__, ret);
 		goto err;

sound/soc/codecs/wm_adsp.c

@@ -998,7 +998,7 @@ int wm_adsp2_preloader_put(struct snd_kcontrol *kcontrol,
 }
 EXPORT_SYMBOL_GPL(wm_adsp2_preloader_put);
 
-int wm_adsp_power_up(struct wm_adsp *dsp)
+int wm_adsp_power_up(struct wm_adsp *dsp, bool load_firmware)
 {
 	int ret = 0;
 	char *wmfw_filename = NULL;
@@ -1006,11 +1006,13 @@ int wm_adsp_power_up(struct wm_adsp *dsp)
 	char *coeff_filename = NULL;
 	const struct firmware *coeff_firmware = NULL;
 
-	ret = wm_adsp_request_firmware_files(dsp,
-					     &wmfw_firmware, &wmfw_filename,
-					     &coeff_firmware, &coeff_filename);
-	if (ret)
-		return ret;
+	if (load_firmware) {
+		ret = wm_adsp_request_firmware_files(dsp,
+						     &wmfw_firmware, &wmfw_filename,
+						     &coeff_firmware, &coeff_filename);
+		if (ret)
+			return ret;
+	}
 
 	ret = cs_dsp_power_up(&dsp->cs_dsp,
 			      wmfw_firmware, wmfw_filename,
@@ -1037,7 +1039,7 @@ static void wm_adsp_boot_work(struct work_struct *work)
 					   struct wm_adsp,
 					   boot_work);
 
-	wm_adsp_power_up(dsp);
+	wm_adsp_power_up(dsp, true);
 }
 
 int wm_adsp_early_event(struct snd_soc_dapm_widget *w,

sound/soc/codecs/wm_adsp.h

@@ -91,7 +91,7 @@ int wm_adsp1_event(struct snd_soc_dapm_widget *w,
 int wm_adsp_early_event(struct snd_soc_dapm_widget *w,
 			struct snd_kcontrol *kcontrol, int event);
 
-int wm_adsp_power_up(struct wm_adsp *dsp);
+int wm_adsp_power_up(struct wm_adsp *dsp, bool load_firmware);
 void wm_adsp_power_down(struct wm_adsp *dsp);
 
 irqreturn_t wm_adsp2_bus_error(int irq, void *data);