soc: ti: k3-ringacc: Allow the driver to be built as module

The ring accelerator driver can be built as module since all depending
functions are exported.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Tested-by: Nicolas Frayer <nfrayer@baylibre.com>
Reviewed-by: Nicolas Frayer <nfrayer@baylibre.com>
Link: https://lore.kernel.org/r/20221029075356.7296-1-peter.ujfalusi@gmail.com

drivers/soc/ti/Kconfig

@@ -63,7 +63,7 @@ config TI_SCI_PM_DOMAINS
 	  rootfs may be available.
 
 config TI_K3_RINGACC
-	bool "K3 Ring accelerator Sub System"
+	tristate "K3 Ring accelerator Sub System"
 	depends on ARCH_K3 || COMPILE_TEST
 	depends on TI_SCI_INTA_IRQCHIP
 	help

drivers/soc/ti/k3-ringacc.c

@@ -7,7 +7,7 @@
 
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
-#include <linux/init.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
@@ -336,6 +336,9 @@ struct k3_ring *k3_ringacc_request_ring(struct k3_ringacc *ringacc,
 
 	mutex_lock(&ringacc->req_lock);
 
+	if (!try_module_get(ringacc->dev->driver->owner))
+		goto err_module_get;
+
 	if (id == K3_RINGACC_RING_ID_ANY) {
 		/* Request for any general purpose ring */
 		struct ti_sci_resource_desc *gp_rings =
@@ -380,6 +383,9 @@ struct k3_ring *k3_ringacc_request_ring(struct k3_ringacc *ringacc,
 	return &ringacc->rings[id];
 
 error:
+	module_put(ringacc->dev->driver->owner);
+
+err_module_get:
 	mutex_unlock(&ringacc->req_lock);
 	return NULL;
 }
@@ -616,6 +622,8 @@ int k3_ringacc_ring_free(struct k3_ring *ring)
 no_init:
 	clear_bit(ring->ring_id, ringacc->rings_inuse);
 
+	module_put(ringacc->dev->driver->owner);
+
 out:
 	mutex_unlock(&ringacc->req_lock);
 	return 0;
@@ -1450,6 +1458,7 @@ static const struct of_device_id k3_ringacc_of_match[] = {
 	{ .compatible = "ti,am654-navss-ringacc", .data = &k3_ringacc_data, },
 	{},
 };
+MODULE_DEVICE_TABLE(of, k3_ringacc_of_match);
 
 struct k3_ringacc *k3_ringacc_dmarings_init(struct platform_device *pdev,
 					    struct k3_ringacc_init_data *data)
@@ -1544,12 +1553,27 @@ static int k3_ringacc_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int k3_ringacc_remove(struct platform_device *pdev)
+{
+	struct k3_ringacc *ringacc = dev_get_drvdata(&pdev->dev);
+
+	mutex_lock(&k3_ringacc_list_lock);
+	list_del(&ringacc->list);
+	mutex_unlock(&k3_ringacc_list_lock);
+	return 0;
+}
+
 static struct platform_driver k3_ringacc_driver = {
 	.probe		= k3_ringacc_probe,
+	.remove		= k3_ringacc_remove,
 	.driver		= {
 		.name	= "k3-ringacc",
 		.of_match_table = k3_ringacc_of_match,
 		.suppress_bind_attrs = true,
 	},
 };
-builtin_platform_driver(k3_ringacc_driver);
+module_platform_driver(k3_ringacc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TI Ringacc driver for K3 SOCs");
+MODULE_AUTHOR("Grygorii Strashko <grygorii.strashko@ti.com>");