remoteproc: pru: Configure firmware based on client setup

Client device node property firmware-name is now used to configure
firmware for the PRU instances. The default firmware is also
restored once releasing the PRU resource.
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230106121046.886863-7-danishanwar@ti.comSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

drivers/remoteproc/pru_rproc.c

@@ -172,6 +172,23 @@ void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
 	spin_unlock_irqrestore(&pru->rmw_lock, flags);
 }
 
+/**
+ * pru_rproc_set_firmware() - set firmware for a PRU core
+ * @rproc: the rproc instance of the PRU
+ * @fw_name: the new firmware name, or NULL if default is desired
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+static int pru_rproc_set_firmware(struct rproc *rproc, const char *fw_name)
+{
+	struct pru_rproc *pru = rproc->priv;
+
+	if (!fw_name)
+		fw_name = pru->fw_name;
+
+	return rproc_set_firmware(rproc, fw_name);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
 	struct rproc *rproc;
@@ -224,6 +241,7 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	struct rproc *rproc;
 	struct pru_rproc *pru;
 	struct device *dev;
+	const char *fw_name;
 	int ret;
 
 	rproc = __pru_rproc_get(np, index);
@@ -249,11 +267,25 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	if (pru_id)
 		*pru_id = pru->id;
 
+	ret = of_property_read_string_index(np, "firmware-name", index,
+					    &fw_name);
+	if (!ret) {
+		ret = pru_rproc_set_firmware(rproc, fw_name);
+		if (ret) {
+			dev_err(dev, "failed to set firmware: %d\n", ret);
+			goto err;
+		}
+	}
+
 	return rproc;
 
 err_no_rproc_handle:
 	rproc_put(rproc);
 	return ERR_PTR(ret);
+
+err:
+	pru_rproc_put(rproc);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(pru_rproc_get);
 
@@ -273,6 +305,8 @@ void pru_rproc_put(struct rproc *rproc)
 
 	pru = rproc->priv;
 
+	pru_rproc_set_firmware(rproc, NULL);
+
 	mutex_lock(&pru->lock);
 
 	if (!pru->client_np) {