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, 322 insertions, 0 deletions

diff --git a/drivers/net/ibm_newemac/zmii.c b/drivers/net/ibm_newemac/zmii.c
new file mode 100644
index 000000000000..d06312901848
--- /dev/null
+++ b/drivers/net/ibm_newemac/zmii.c
@@ -0,0 +1,322 @@
+/*
+ * drivers/net/ibm_newemac/zmii.c
+ *
+ * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
+ *
+ * Copyright (c) 2004, 2005 Zultys Technologies.
+ * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
+ *
+ * Based on original work by
+ *      Armin Kuster <akuster@mvista.com>
+ * 	Copyright 2001 MontaVista Softare 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 "core.h"
+
+/* ZMIIx_FER */
+#define ZMII_FER_MDI(idx)	(0x80000000 >> ((idx) * 4))
+#define ZMII_FER_MDI_ALL	(ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
+				 ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
+
+#define ZMII_FER_SMII(idx)	(0x40000000 >> ((idx) * 4))
+#define ZMII_FER_RMII(idx)	(0x20000000 >> ((idx) * 4))
+#define ZMII_FER_MII(idx)	(0x10000000 >> ((idx) * 4))
+
+/* ZMIIx_SSR */
+#define ZMII_SSR_SCI(idx)	(0x40000000 >> ((idx) * 4))
+#define ZMII_SSR_FSS(idx)	(0x20000000 >> ((idx) * 4))
+#define ZMII_SSR_SP(idx)	(0x10000000 >> ((idx) * 4))
+
+/* ZMII only supports MII, RMII and SMII
+ * we also support autodetection for backward compatibility
+ */
+static inline int zmii_valid_mode(int mode)
+{
+	return  mode == PHY_MODE_MII ||
+		mode == PHY_MODE_RMII ||
+		mode == PHY_MODE_SMII ||
+		mode == PHY_MODE_NA;
+}
+
+static inline const char *zmii_mode_name(int mode)
+{
+	switch (mode) {
+	case PHY_MODE_MII:
+		return "MII";
+	case PHY_MODE_RMII:
+		return "RMII";
+	case PHY_MODE_SMII:
+		return "SMII";
+	default:
+		BUG();
+	}
+}
+
+static inline u32 zmii_mode_mask(int mode, int input)
+{
+	switch (mode) {
+	case PHY_MODE_MII:
+		return ZMII_FER_MII(input);
+	case PHY_MODE_RMII:
+		return ZMII_FER_RMII(input);
+	case PHY_MODE_SMII:
+		return ZMII_FER_SMII(input);
+	default:
+		return 0;
+	}
+}
+
+int __devinit zmii_attach(struct of_device *ofdev, int input, int *mode)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct zmii_regs *p = dev->base;
+
+	ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
+
+	if (!zmii_valid_mode(*mode))
+		/* Probably an EMAC connected to RGMII,
+		 * but it still may need ZMII for MDIO so
+		 * we don't fail here.
+		 */
+		return 0;
+
+	mutex_lock(&dev->lock);
+
+	/* Autodetect ZMII mode if not specified.
+	 * This is only for backward compatibility with the old driver.
+	 * Please, always specify PHY mode in your board port to avoid
+	 * any surprises.
+	 */
+	if (dev->mode == PHY_MODE_NA) {
+		if (*mode == PHY_MODE_NA) {
+			u32 r = dev->fer_save;
+
+			ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
+
+			if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
+				dev->mode = PHY_MODE_MII;
+			else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
+				dev->mode = PHY_MODE_RMII;
+			else
+				dev->mode = PHY_MODE_SMII;
+		} else
+			dev->mode = *mode;
+
+		printk(KERN_NOTICE "%s: bridge in %s mode\n",
+		       ofdev->node->full_name, zmii_mode_name(dev->mode));
+	} else {
+		/* All inputs must use the same mode */
+		if (*mode != PHY_MODE_NA && *mode != dev->mode) {
+			printk(KERN_ERR
+			       "%s: invalid mode %d specified for input %d\n",
+			       ofdev->node->full_name, *mode, input);
+			mutex_unlock(&dev->lock);
+			return -EINVAL;
+		}
+	}
+
+	/* Report back correct PHY mode,
+	 * it may be used during PHY initialization.
+	 */
+	*mode = dev->mode;
+
+	/* Enable this input */
+	out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
+	++dev->users;
+
+	mutex_unlock(&dev->lock);
+
+	return 0;
+}
+
+void zmii_get_mdio(struct of_device *ofdev, int input)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	u32 fer;
+
+	ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
+
+	mutex_lock(&dev->lock);
+
+	fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
+	out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
+}
+
+void zmii_put_mdio(struct of_device *ofdev, int input)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+
+	ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
+	mutex_unlock(&dev->lock);
+}
+
+
+void zmii_set_speed(struct of_device *ofdev, int input, int speed)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	u32 ssr;
+
+	mutex_lock(&dev->lock);
+
+	ssr = in_be32(&dev->base->ssr);
+
+	ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
+
+	if (speed == SPEED_100)
+		ssr |= ZMII_SSR_SP(input);
+	else
+		ssr &= ~ZMII_SSR_SP(input);
+
+	out_be32(&dev->base->ssr, ssr);
+
+	mutex_unlock(&dev->lock);
+}
+
+void __devexit zmii_detach(struct of_device *ofdev, int input)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+
+	BUG_ON(!dev || dev->users == 0);
+
+	mutex_lock(&dev->lock);
+
+	ZMII_DBG(dev, "detach(%d)" NL, input);
+
+	/* Disable this input */
+	out_be32(&dev->base->fer,
+		 in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
+
+	--dev->users;
+
+	mutex_unlock(&dev->lock);
+}
+
+int zmii_get_regs_len(struct of_device *ofdev)
+{
+	return sizeof(struct emac_ethtool_regs_subhdr) +
+		sizeof(struct zmii_regs);
+}
+
+void *zmii_dump_regs(struct of_device *ofdev, void *buf)
+{
+	struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
+	struct emac_ethtool_regs_subhdr *hdr = buf;
+	struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
+
+	hdr->version = 0;
+	hdr->index = 0; /* for now, are there chips with more than one
+			 * zmii ? if yes, then we'll add a cell_index
+			 * like we do for emac
+			 */
+	memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
+	return regs + 1;
+}
+
+static int __devinit zmii_probe(struct of_device *ofdev,
+				const struct of_device_id *match)
+{
+	struct device_node *np = ofdev->node;
+	struct zmii_instance *dev;
+	struct resource regs;
+	int rc;
+
+	rc = -ENOMEM;
+	dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
+	if (dev == NULL) {
+		printk(KERN_ERR "%s: could not allocate ZMII device!\n",
+		       np->full_name);
+		goto err_gone;
+	}
+
+	mutex_init(&dev->lock);
+	dev->ofdev = ofdev;
+	dev->mode = PHY_MODE_NA;
+
+	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 zmii_regs *)ioremap(regs.start,
+						sizeof(struct zmii_regs));
+	if (dev->base == NULL) {
+		printk(KERN_ERR "%s: Can't map device registers!\n",
+		       np->full_name);
+		goto err_free;
+	}
+
+	/* We may need FER value for autodetection later */
+	dev->fer_save = in_be32(&dev->base->fer);
+
+	/* Disable all inputs by default */
+	out_be32(&dev->base->fer, 0);
+
+	printk(KERN_INFO
+	       "ZMII %s initialized\n", ofdev->node->full_name);
+	wmb();
+	dev_set_drvdata(&ofdev->dev, dev);
+
+	return 0;
+
+ err_free:
+	kfree(dev);
+ err_gone:
+	return rc;
+}
+
+static int __devexit zmii_remove(struct of_device *ofdev)
+{
+	struct zmii_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 zmii_match[] =
+{
+	{
+		.compatible	= "ibm,zmii",
+	},
+	/* For backward compat with old DT */
+	{
+		.type		= "emac-zmii",
+	},
+	{},
+};
+
+static struct of_platform_driver zmii_driver = {
+	.name = "emac-zmii",
+	.match_table = zmii_match,
+
+	.probe = zmii_probe,
+	.remove = zmii_remove,
+};
+
+int __init zmii_init(void)
+{
+	return of_register_platform_driver(&zmii_driver);
+}
+
+void zmii_exit(void)
+{
+	of_unregister_platform_driver(&zmii_driver);
+}