soc: ti: K2G: provide APIs to support driver probe deferral

This patch provide APIs to allow client drivers to support
probe deferral. On K2G SoC, devices can be probed only
after the ti_sci_pm_domains driver is probed and ready.
As drivers may get probed at different order, any driver
that depends on knav dma and qmss drivers, for example
netcp network driver, needs to defer probe until
knav devices are probed and ready to service. To do this,
add an API to query the device ready status from the knav
dma and qmss devices.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/soc/ti/knav_dma.c

@@ -134,6 +134,13 @@ struct knav_dma_chan {
 
 static struct knav_dma_pool_device *kdev;
 
+static bool device_ready;
+bool knav_dma_device_ready(void)
+{
+	return device_ready;
+}
+EXPORT_SYMBOL_GPL(knav_dma_device_ready);
+
 static bool check_config(struct knav_dma_chan *chan, struct knav_dma_cfg *cfg)
 {
 	if (!memcmp(&chan->cfg, cfg, sizeof(*cfg)))
@@ -773,6 +780,7 @@ static int knav_dma_probe(struct platform_device *pdev)
 	debugfs_create_file("knav_dma", S_IFREG | S_IRUGO, NULL, NULL,
 			    &knav_dma_debug_ops);
 
+	device_ready = true;
 	return ret;
 }
 

drivers/soc/ti/knav_qmss_queue.c

@@ -74,6 +74,13 @@ static DEFINE_MUTEX(knav_dev_lock);
  */
 const char *knav_acc_firmwares[] = {"ks2_qmss_pdsp_acc48.bin"};
 
+static bool device_ready;
+bool knav_qmss_device_ready(void)
+{
+	return device_ready;
+}
+EXPORT_SYMBOL_GPL(knav_qmss_device_ready);
+
 /**
  * knav_queue_notify: qmss queue notfier call
  *
@@ -1849,6 +1856,7 @@ static int knav_queue_probe(struct platform_device *pdev)
 
 	debugfs_create_file("qmss", S_IFREG | S_IRUGO, NULL, NULL,
 			    &knav_queue_debug_ops);
+	device_ready = true;
 	return 0;
 
 err: