Device tree aware EMAC driver

Based on BenH's earlier work, this is a new version of the EMAC driver
for the built-in ethernet found on PowerPC 4xx embedded CPUs.  The
same ASIC is also found in the Axon bridge chip.  This new version is
designed to work in the arch/powerpc tree, using the device tree to
probe the device, rather than the old and ugly arch/ppc OCP layer.

This driver is designed to sit alongside the old driver (that lies in
drivers/net/ibm_emac and this one in drivers/net/ibm_newemac).  The
old driver is left in place to support arch/ppc until arch/ppc itself
reaches its final demise (not too long now, with luck).

This driver still has a number of things that could do with cleaning
up, but I think they can be fixed up after merging.  Specifically:
	- Should be adjusted to properly use the dma mapping API.
Axon needs this.
	- Probe logic needs reworking, in conjuction with the general
probing code for of_platform devices.  The dependencies here between
EMAC, MAL, ZMII etc. make this complicated.  At present, it usually
works, because we initialize and register the sub-drivers before the
EMAC driver itself, and (being in driver code) runs after the devices
themselves have been instantiated from the device tree.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 323 insertions, 0 deletions

diff --git a/drivers/net/ibm_newemac/rgmii.c b/drivers/net/ibm_newemac/rgmii.c
new file mode 100644
index 0000000..bcd7fc6
--- /dev/null
+++ b/drivers/net/ibm_newemac/rgmii.c
@@ -0,0 +1,323 @@
+/*
+ * drivers/net/ibm_newemac/rgmii.c
+ *
+ * Driver for PowerPC 4xx on-chip ethernet controller, RGMII bridge support.
+ *
+ * Copyright (c) 2004, 2005 Zultys Technologies.
+ * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
+ *
+ * Based on original work by
+ * 	Matt Porter <mporter@kernel.crashing.org>
+ * 	Copyright 2004 MontaVista Software, Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/ethtool.h>
+#include <asm/io.h>
+
+#include "emac.h"
+#include "debug.h"
+
+// XXX FIXME: Axon seems to support a subset of the RGMII, we
+// thus need to take that into account and possibly change some
+// of the bit settings below that don't seem to quite match the
+// AXON spec
+
+/* RGMIIx_FER */
+#define RGMII_FER_MASK(idx)	(0x7 << ((idx) * 4))
+#define RGMII_FER_RTBI(idx)	(0x4 << ((idx) * 4))
+#define RGMII_FER_RGMII(idx)	(0x5 << ((idx) * 4))
+#define RGMII_FER_TBI(idx)	(0x6 << ((idx) * 4))
+#define RGMII_FER_GMII(idx)	(0x7 << ((idx) * 4))
+
+/* RGMIIx_SSR */
+#define RGMII_SSR_MASK(idx)	(0x7 << ((idx) * 8))
+#define RGMII_SSR_100(idx)	(0x2 << ((idx) * 8))
+#define RGMII_SSR_1000(idx)	(0x4 << ((idx) * 8))
+
+/* RGMII bridge supports only GMII/TBI and RGMII/RTBI PHYs */
+static inline int rgmii_valid_mode(int phy_mode)
+{
+	return  phy_mode == PHY_MODE_GMII ||
+		phy_mode == PHY_MODE_RGMII ||
+		phy_mode == PHY_MODE_TBI ||
+		phy_mode == PHY_MODE_RTBI;
+}
+
+static inline const char *rgmii_mode_name(int mode)
+{
+	switch (mode) {
+	case PHY_MODE_RGMII:
+		return "RGMII";
+	case PHY_MODE_TBI:
+		return "TBI";
+	case PHY_MODE_GMII:
+		return "GMII";
+	case PHY_MODE_RTBI:
+		return "RTBI";
+	default:
+		BUG();
+	}
+}
+
+static inline u32 rgmii_mode_mask(int mode, int input)
+{
+	switch (mode) {
+	case PHY_MODE_RGMII:
+		return RGMII_FER_RGMII(input);
+	case PHY_MODE_TBI:
+		return RGMII_FER_TBI(input);
+	case PHY_MODE_GMII:
+		return RGMII_FER_GMII(input);
+	case PHY_MODE_RTBI:
+		return RGMII_FER_RTBI(input);
+	default:
+		BUG();
+	}
+}
+
+int __devinit rgmii_attach(struct of_device *ofdev, int input, int mode)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct rgmii_regs *p = dev->base;
+
+	RGMII_DBG(dev, "attach(%d)" NL, input);
+
+	/* Check if we need to attach to a RGMII */
+	if (input < 0 || !rgmii_valid_mode(mode)) {
+		printk(KERN_ERR "%s: unsupported settings !\n",
+		       ofdev->node->full_name);
+		return -ENODEV;
+	}
+
+	mutex_lock(&dev->lock);
+
+	/* Enable this input */
+	out_be32(&p->fer, in_be32(&p->fer) | rgmii_mode_mask(mode, input));
+
+	printk(KERN_NOTICE "%s: input %d in %s mode\n",
+	       ofdev->node->full_name, input, rgmii_mode_name(mode));
+
+	++dev->users;
+
+	mutex_unlock(&dev->lock);
+
+	return 0;
+}
+
+void rgmii_set_speed(struct of_device *ofdev, int input, int speed)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct rgmii_regs *p = dev->base;
+	u32 ssr;
+
+	mutex_lock(&dev->lock);
+
+	ssr = in_be32(&p->ssr) & ~RGMII_SSR_MASK(input);
+
+	RGMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
+
+	if (speed == SPEED_1000)
+		ssr |= RGMII_SSR_1000(input);
+	else if (speed == SPEED_100)
+		ssr |= RGMII_SSR_100(input);
+
+	out_be32(&p->ssr, ssr);
+
+	mutex_unlock(&dev->lock);
+}
+
+void rgmii_get_mdio(struct of_device *ofdev, int input)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct rgmii_regs *p = dev->base;
+	u32 fer;
+
+	RGMII_DBG2(dev, "get_mdio(%d)" NL, input);
+
+	if (dev->type != RGMII_AXON)
+		return;
+
+	mutex_lock(&dev->lock);
+
+	fer = in_be32(&p->fer);
+	fer |= 0x00080000u >> input;
+	out_be32(&p->fer, fer);
+	(void)in_be32(&p->fer);
+
+	DBG2(dev, " fer = 0x%08x\n", fer);
+}
+
+void rgmii_put_mdio(struct of_device *ofdev, int input)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct rgmii_regs *p = dev->base;
+	u32 fer;
+
+	RGMII_DBG2(dev, "put_mdio(%d)" NL, input);
+
+	if (dev->type != RGMII_AXON)
+		return;
+
+	fer = in_be32(&p->fer);
+	fer &= ~(0x00080000u >> input);
+	out_be32(&p->fer, fer);
+	(void)in_be32(&p->fer);
+
+	DBG2(dev, " fer = 0x%08x\n", fer);
+
+	mutex_unlock(&dev->lock);
+}
+
+void __devexit rgmii_detach(struct of_device *ofdev, int input)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct rgmii_regs *p = dev->base;
+
+	mutex_lock(&dev->lock);
+
+	BUG_ON(!dev || dev->users == 0);
+
+	RGMII_DBG(dev, "detach(%d)" NL, input);
+
+	/* Disable this input */
+	out_be32(&p->fer, in_be32(&p->fer) & ~RGMII_FER_MASK(input));
+
+	--dev->users;
+
+	mutex_unlock(&dev->lock);
+}
+
+int rgmii_get_regs_len(struct of_device *ofdev)
+{
+	return sizeof(struct emac_ethtool_regs_subhdr) +
+		sizeof(struct rgmii_regs);
+}
+
+void *rgmii_dump_regs(struct of_device *ofdev, void *buf)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct emac_ethtool_regs_subhdr *hdr = buf;
+	struct rgmii_regs *regs = (struct rgmii_regs *)(hdr + 1);
+
+	hdr->version = 0;
+	hdr->index = 0; /* for now, are there chips with more than one
+			 * rgmii ? if yes, then we'll add a cell_index
+			 * like we do for emac
+			 */
+	memcpy_fromio(regs, dev->base, sizeof(struct rgmii_regs));
+	return regs + 1;
+}
+
+
+static int __devinit rgmii_probe(struct of_device *ofdev,
+				 const struct of_device_id *match)
+{
+	struct device_node *np = ofdev->node;
+	struct rgmii_instance *dev;
+	struct resource regs;
+	int rc;
+
+	rc = -ENOMEM;
+	dev = kzalloc(sizeof(struct rgmii_instance), GFP_KERNEL);
+	if (dev == NULL) {
+		printk(KERN_ERR "%s: could not allocate RGMII device!\n",
+		       np->full_name);
+		goto err_gone;
+	}
+
+	mutex_init(&dev->lock);
+	dev->ofdev = ofdev;
+
+	rc = -ENXIO;
+	if (of_address_to_resource(np, 0, &regs)) {
+		printk(KERN_ERR "%s: Can't get registers address\n",
+		       np->full_name);
+		goto err_free;
+	}
+
+	rc = -ENOMEM;
+	dev->base = (struct rgmii_regs *)ioremap(regs.start,
+						 sizeof(struct rgmii_regs));
+	if (dev->base == NULL) {
+		printk(KERN_ERR "%s: Can't map device registers!\n",
+		       np->full_name);
+		goto err_free;
+	}
+
+	/* Check for RGMII type */
+	if (device_is_compatible(ofdev->node, "ibm,rgmii-axon"))
+		dev->type = RGMII_AXON;
+	else
+		dev->type = RGMII_STANDARD;
+
+	DBG2(dev, " Boot FER = 0x%08x, SSR = 0x%08x\n",
+	     in_be32(&dev->base->fer), in_be32(&dev->base->ssr));
+
+	/* Disable all inputs by default */
+	out_be32(&dev->base->fer, 0);
+
+	printk(KERN_INFO
+	       "RGMII %s %s initialized\n",
+	       dev->type == RGMII_STANDARD ? "standard" : "axon",
+	       ofdev->node->full_name);
+
+	wmb();
+	dev_set_drvdata(&ofdev->dev, dev);
+
+	return 0;
+
+ err_free:
+	kfree(dev);
+ err_gone:
+	return rc;
+}
+
+static int __devexit rgmii_remove(struct of_device *ofdev)
+{
+	struct rgmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+
+	dev_set_drvdata(&ofdev->dev, NULL);
+
+	WARN_ON(dev->users != 0);
+
+	iounmap(dev->base);
+	kfree(dev);
+
+	return 0;
+}
+
+static struct of_device_id rgmii_match[] =
+{
+	{
+		.type		= "rgmii-interface",
+		.compatible	= "ibm,rgmii",
+	},
+	{
+		.type		= "emac-rgmii",
+	},
+	{},
+};
+
+static struct of_platform_driver rgmii_driver = {
+	.name = "emac-rgmii",
+	.match_table = rgmii_match,
+
+	.probe = rgmii_probe,
+	.remove = rgmii_remove,
+};
+
+int __init rgmii_init(void)
+{
+	return of_register_platform_driver(&rgmii_driver);
+}
+
+void rgmii_exit(void)
+{
+	of_unregister_platform_driver(&rgmii_driver);
+}