cdx: add cdx controller

CDX controller uses MCDI interface as a protocol to
communicate with the RPU firmware and registers the
detected CDX devices on the CDX bus. It also uses
RPMsg as the communication channel with the Firmware.

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Signed-off-by: Puneet Gupta <puneet.gupta@amd.com>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Signed-off-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230313132636.31850-6-nipun.gupta@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 188 insertions, 0 deletions

diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c
new file mode 100644
index 000000000000..fbebc8cdcbf8
--- /dev/null
+++ b/drivers/cdx/controller/cdx_controller.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CDX host controller driver for AMD versal-net platform.
+ *
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/cdx/cdx_bus.h>
+
+#include "../cdx.h"
+#include "mcdi_functions.h"
+#include "mcdi.h"
+
+static unsigned int cdx_mcdi_rpc_timeout(struct cdx_mcdi *cdx, unsigned int cmd)
+{
+	return MCDI_RPC_TIMEOUT;
+}
+
+static void cdx_mcdi_request(struct cdx_mcdi *cdx,
+			     const struct cdx_dword *hdr, size_t hdr_len,
+			     const struct cdx_dword *sdu, size_t sdu_len)
+{
+	/*
+	 * This will get updated by rpmsg APIs, with RPMSG introduction
+	 * in CDX controller as a transport layer.
+	 */
+}
+
+static const struct cdx_mcdi_ops mcdi_ops = {
+	.mcdi_rpc_timeout = cdx_mcdi_rpc_timeout,
+	.mcdi_request = cdx_mcdi_request,
+};
+
+static int cdx_scan_devices(struct cdx_controller *cdx)
+{
+	struct cdx_mcdi *cdx_mcdi = cdx->priv;
+	u8 bus_num, dev_num, num_cdx_bus;
+	int ret;
+
+	/* MCDI FW Read: Fetch the number of CDX buses on this controller */
+	ret = cdx_mcdi_get_num_buses(cdx_mcdi);
+	if (ret < 0) {
+		dev_err(cdx->dev,
+			"Get number of CDX buses failed: %d\n", ret);
+		return ret;
+	}
+	num_cdx_bus = (u8)ret;
+
+	for (bus_num = 0; bus_num < num_cdx_bus; bus_num++) {
+		u8 num_cdx_dev;
+
+		/* MCDI FW Read: Fetch the number of devices present */
+		ret = cdx_mcdi_get_num_devs(cdx_mcdi, bus_num);
+		if (ret < 0) {
+			dev_err(cdx->dev,
+				"Get devices on CDX bus %d failed: %d\n", bus_num, ret);
+			continue;
+		}
+		num_cdx_dev = (u8)ret;
+
+		for (dev_num = 0; dev_num < num_cdx_dev; dev_num++) {
+			struct cdx_dev_params dev_params;
+
+			/* MCDI FW: Get the device config */
+			ret = cdx_mcdi_get_dev_config(cdx_mcdi, bus_num,
+						      dev_num, &dev_params);
+			if (ret) {
+				dev_err(cdx->dev,
+					"CDX device config get failed for %d(bus):%d(dev), %d\n",
+					bus_num, dev_num, ret);
+				continue;
+			}
+			dev_params.cdx = cdx;
+
+			/* Add the device to the cdx bus */
+			ret = cdx_device_add(&dev_params);
+			if (ret) {
+				dev_err(cdx->dev, "registering cdx dev: %d failed: %d\n",
+					dev_num, ret);
+				continue;
+			}
+
+			dev_dbg(cdx->dev, "CDX dev: %d on cdx bus: %d created\n",
+				dev_num, bus_num);
+		}
+	}
+
+	return 0;
+}
+
+static struct cdx_ops cdx_ops = {
+	.scan		= cdx_scan_devices,
+};
+
+static int xlnx_cdx_probe(struct platform_device *pdev)
+{
+	struct cdx_controller *cdx;
+	struct cdx_mcdi *cdx_mcdi;
+	int ret;
+
+	cdx_mcdi = kzalloc(sizeof(*cdx_mcdi), GFP_KERNEL);
+	if (!cdx_mcdi)
+		return -ENOMEM;
+
+	/* Store the MCDI ops */
+	cdx_mcdi->mcdi_ops = &mcdi_ops;
+	/* MCDI FW: Initialize the FW path */
+	ret = cdx_mcdi_init(cdx_mcdi);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "MCDI Initialization failed\n");
+		goto mcdi_init_fail;
+	}
+
+	cdx = kzalloc(sizeof(*cdx), GFP_KERNEL);
+	if (!cdx) {
+		ret = -ENOMEM;
+		goto cdx_alloc_fail;
+	}
+	platform_set_drvdata(pdev, cdx);
+
+	cdx->dev = &pdev->dev;
+	cdx->priv = cdx_mcdi;
+	cdx->ops = &cdx_ops;
+
+	return 0;
+
+cdx_alloc_fail:
+	cdx_mcdi_finish(cdx_mcdi);
+mcdi_init_fail:
+	kfree(cdx_mcdi);
+
+	return ret;
+}
+
+static int xlnx_cdx_remove(struct platform_device *pdev)
+{
+	struct cdx_controller *cdx = platform_get_drvdata(pdev);
+	struct cdx_mcdi *cdx_mcdi = cdx->priv;
+
+	kfree(cdx);
+
+	cdx_mcdi_finish(cdx_mcdi);
+	kfree(cdx_mcdi);
+
+	return 0;
+}
+
+static const struct of_device_id cdx_match_table[] = {
+	{.compatible = "xlnx,versal-net-cdx",},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, cdx_match_table);
+
+static struct platform_driver cdx_pdriver = {
+	.driver = {
+		   .name = "cdx-controller",
+		   .pm = NULL,
+		   .of_match_table = cdx_match_table,
+		   },
+	.probe = xlnx_cdx_probe,
+	.remove = xlnx_cdx_remove,
+};
+
+static int __init cdx_controller_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&cdx_pdriver);
+	if (ret)
+		pr_err("platform_driver_register() failed: %d\n", ret);
+
+	return ret;
+}
+
+static void __exit cdx_controller_exit(void)
+{
+	platform_driver_unregister(&cdx_pdriver);
+}
+
+module_init(cdx_controller_init);
+module_exit(cdx_controller_exit);
+
+MODULE_AUTHOR("AMD Inc.");
+MODULE_DESCRIPTION("CDX controller for AMD devices");
+MODULE_LICENSE("GPL");