fpga: dfl: afu: add port ops support

This patch registers the port ops into the global list in the DFL
framework, and it allows other modules to use the port ops. And
This patch includes the implementation of the get_id and enable_set
ops too.
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fpga/dfl-afu-main.c

@@ -19,6 +19,83 @@
 
 #include "dfl.h"
 
+/**
+ * port_enable - enable a port
+ * @pdev: port platform device.
+ *
+ * Enable Port by clear the port soft reset bit, which is set by default.
+ * The User AFU is unable to respond to any MMIO access while in reset.
+ * port_enable function should only be used after port_disable
+ * function.
+ */
+static void port_enable(struct platform_device *pdev)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	void __iomem *base;
+	u64 v;
+
+	WARN_ON(!pdata->disable_count);
+
+	if (--pdata->disable_count != 0)
+		return;
+
+	base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER);
+
+	/* Clear port soft reset */
+	v = readq(base + PORT_HDR_CTRL);
+	v &= ~PORT_CTRL_SFTRST;
+	writeq(v, base + PORT_HDR_CTRL);
+}
+
+#define RST_POLL_INVL 10 /* us */
+#define RST_POLL_TIMEOUT 1000 /* us */
+
+/**
+ * port_disable - disable a port
+ * @pdev: port platform device.
+ *
+ * Disable Port by setting the port soft reset bit, it puts the port into
+ * reset.
+ */
+static int port_disable(struct platform_device *pdev)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	void __iomem *base;
+	u64 v;
+
+	if (pdata->disable_count++ != 0)
+		return 0;
+
+	base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER);
+
+	/* Set port soft reset */
+	v = readq(base + PORT_HDR_CTRL);
+	v |= PORT_CTRL_SFTRST;
+	writeq(v, base + PORT_HDR_CTRL);
+
+	/*
+	 * HW sets ack bit to 1 when all outstanding requests have been drained
+	 * on this port and minimum soft reset pulse width has elapsed.
+	 * Driver polls port_soft_reset_ack to determine if reset done by HW.
+	 */
+	if (readq_poll_timeout(base + PORT_HDR_CTRL, v, v & PORT_CTRL_SFTRST,
+			       RST_POLL_INVL, RST_POLL_TIMEOUT)) {
+		dev_err(&pdev->dev, "timeout, fail to reset device\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int port_get_id(struct platform_device *pdev)
+{
+	void __iomem *base;
+
+	base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER);
+
+	return FIELD_GET(PORT_CAP_PORT_NUM, readq(base + PORT_HDR_CAP));
+}
+
 static int port_hdr_init(struct platform_device *pdev,
 			 struct dfl_feature *feature)
 {
@@ -119,6 +196,28 @@ static const struct file_operations afu_fops = {
 	.unlocked_ioctl = afu_ioctl,
 };
 
+static int port_enable_set(struct platform_device *pdev, bool enable)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	int ret = 0;
+
+	mutex_lock(&pdata->lock);
+	if (enable)
+		port_enable(pdev);
+	else
+		ret = port_disable(pdev);
+	mutex_unlock(&pdata->lock);
+
+	return ret;
+}
+
+static struct dfl_fpga_port_ops afu_port_ops = {
+	.name = DFL_FPGA_FEATURE_DEV_PORT,
+	.owner = THIS_MODULE,
+	.get_id = port_get_id,
+	.enable_set = port_enable_set,
+};
+
 static int afu_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -154,7 +253,28 @@ static struct platform_driver afu_driver = {
 	.remove  = afu_remove,
 };
 
-module_platform_driver(afu_driver);
+static int __init afu_init(void)
+{
+	int ret;
+
+	dfl_fpga_port_ops_add(&afu_port_ops);
+
+	ret = platform_driver_register(&afu_driver);
+	if (ret)
+		dfl_fpga_port_ops_del(&afu_port_ops);
+
+	return ret;
+}
+
+static void __exit afu_exit(void)
+{
+	platform_driver_unregister(&afu_driver);
+
+	dfl_fpga_port_ops_del(&afu_port_ops);
+}
+
+module_init(afu_init);
+module_exit(afu_exit);
 
 MODULE_DESCRIPTION("FPGA Accelerated Function Unit driver");
 MODULE_AUTHOR("Intel Corporation");