Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/drivers/net/mdio/mdio-mux-mmioreg.c b/drivers/net/mdio/mdio-mux-mmioreg.c
new file mode 100644
index 0000000000..09af150ed7
--- /dev/null
+++ b/drivers/net/mdio/mdio-mux-mmioreg.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simple memory-mapped device MDIO MUX driver
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/mdio-mux.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+
+struct mdio_mux_mmioreg_state {
+	void *mux_handle;
+	phys_addr_t phys;
+	unsigned int iosize;
+	unsigned int mask;
+};
+
+/*
+ * MDIO multiplexing switch function
+ *
+ * This function is called by the mdio-mux layer when it thinks the mdio bus
+ * multiplexer needs to switch.
+ *
+ * 'current_child' is the current value of the mux register (masked via
+ * s->mask).
+ *
+ * 'desired_child' is the value of the 'reg' property of the target child MDIO
+ * node.
+ *
+ * The first time this function is called, current_child == -1.
+ *
+ * If current_child == desired_child, then the mux is already set to the
+ * correct bus.
+ */
+static int mdio_mux_mmioreg_switch_fn(int current_child, int desired_child,
+				      void *data)
+{
+	struct mdio_mux_mmioreg_state *s = data;
+
+	if (current_child ^ desired_child) {
+		void __iomem *p = ioremap(s->phys, s->iosize);
+		if (!p)
+			return -ENOMEM;
+
+		switch (s->iosize) {
+		case sizeof(uint8_t): {
+			uint8_t x, y;
+
+			x = ioread8(p);
+			y = (x & ~s->mask) | desired_child;
+			if (x != y) {
+				iowrite8((x & ~s->mask) | desired_child, p);
+				pr_debug("%s: %02x -> %02x\n", __func__, x, y);
+			}
+
+			break;
+		}
+		case sizeof(uint16_t): {
+			uint16_t x, y;
+
+			x = ioread16(p);
+			y = (x & ~s->mask) | desired_child;
+			if (x != y) {
+				iowrite16((x & ~s->mask) | desired_child, p);
+				pr_debug("%s: %04x -> %04x\n", __func__, x, y);
+			}
+
+			break;
+		}
+		case sizeof(uint32_t): {
+			uint32_t x, y;
+
+			x = ioread32(p);
+			y = (x & ~s->mask) | desired_child;
+			if (x != y) {
+				iowrite32((x & ~s->mask) | desired_child, p);
+				pr_debug("%s: %08x -> %08x\n", __func__, x, y);
+			}
+
+			break;
+		}
+		}
+
+		iounmap(p);
+	}
+
+	return 0;
+}
+
+static int mdio_mux_mmioreg_probe(struct platform_device *pdev)
+{
+	struct device_node *np2, *np = pdev->dev.of_node;
+	struct mdio_mux_mmioreg_state *s;
+	struct resource res;
+	const __be32 *iprop;
+	int len, ret;
+
+	dev_dbg(&pdev->dev, "probing node %pOF\n", np);
+
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		dev_err(&pdev->dev, "could not obtain memory map for node %pOF\n",
+			np);
+		return ret;
+	}
+	s->phys = res.start;
+
+	s->iosize = resource_size(&res);
+	if (s->iosize != sizeof(uint8_t) &&
+	    s->iosize != sizeof(uint16_t) &&
+	    s->iosize != sizeof(uint32_t)) {
+		dev_err(&pdev->dev, "only 8/16/32-bit registers are supported\n");
+		return -EINVAL;
+	}
+
+	iprop = of_get_property(np, "mux-mask", &len);
+	if (!iprop || len != sizeof(uint32_t)) {
+		dev_err(&pdev->dev, "missing or invalid mux-mask property\n");
+		return -ENODEV;
+	}
+	if (be32_to_cpup(iprop) >= BIT(s->iosize * 8)) {
+		dev_err(&pdev->dev, "only 8/16/32-bit registers are supported\n");
+		return -EINVAL;
+	}
+	s->mask = be32_to_cpup(iprop);
+
+	/*
+	 * Verify that the 'reg' property of each child MDIO bus does not
+	 * set any bits outside of the 'mask'.
+	 */
+	for_each_available_child_of_node(np, np2) {
+		u64 reg;
+
+		if (of_property_read_reg(np2, 0, &reg, NULL)) {
+			dev_err(&pdev->dev, "mdio-mux child node %pOF is "
+				"missing a 'reg' property\n", np2);
+			of_node_put(np2);
+			return -ENODEV;
+		}
+		if ((u32)reg & ~s->mask) {
+			dev_err(&pdev->dev, "mdio-mux child node %pOF has "
+				"a 'reg' value with unmasked bits\n",
+				np2);
+			of_node_put(np2);
+			return -ENODEV;
+		}
+	}
+
+	ret = mdio_mux_init(&pdev->dev, pdev->dev.of_node,
+			    mdio_mux_mmioreg_switch_fn,
+			    &s->mux_handle, s, NULL);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "failed to register mdio-mux bus %pOF\n", np);
+
+	pdev->dev.platform_data = s;
+
+	return 0;
+}
+
+static int mdio_mux_mmioreg_remove(struct platform_device *pdev)
+{
+	struct mdio_mux_mmioreg_state *s = dev_get_platdata(&pdev->dev);
+
+	mdio_mux_uninit(s->mux_handle);
+
+	return 0;
+}
+
+static const struct of_device_id mdio_mux_mmioreg_match[] = {
+	{
+		.compatible = "mdio-mux-mmioreg",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mdio_mux_mmioreg_match);
+
+static struct platform_driver mdio_mux_mmioreg_driver = {
+	.driver = {
+		.name		= "mdio-mux-mmioreg",
+		.of_match_table = mdio_mux_mmioreg_match,
+	},
+	.probe		= mdio_mux_mmioreg_probe,
+	.remove		= mdio_mux_mmioreg_remove,
+};
+
+module_platform_driver(mdio_mux_mmioreg_driver);
+
+MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
+MODULE_DESCRIPTION("Memory-mapped device MDIO MUX driver");
+MODULE_LICENSE("GPL v2");