net: dsa: realtek-smi: Add Realtek SMI driver

This adds a driver core for the Realtek SMI chips and a
subdriver for the RTL8366RB. I just added this chip simply
because it is all I can test.

The code is a massaged variant of the code that has been
sitting out-of-tree in OpenWRT for years in the absence of
a proper switch subsystem. This creates a DSA driver for it.
I have tried to credit the original authors wherever
possible.

The main changes I've done from the OpenWRT code:

- Added an IRQ chip inside the RTL8366RB switch to demux and
  handle the line state IRQs.

- Distributed the phy handling out to the PHY driver.

- Added some RTL8366RB code that was missing in the driver at
  the time, such as setting up "green ethernet" with a funny
  jam table and forcing MAC5 (the CPU port) into 1 GBit.

- Select jam table and add the default jam table from the
  vendor driver, also for ASIC "version 0" if need be.

- Do not store jam tables in the device tree, store them
  in the driver.

- Pick in the "initvals" jam tables from OpenWRT's driver
  and make those get selected per compatible for the
  whole system. It's apparently about electrical settings
  for this system and whatnot, not really configuration
  from device tree.

- Implemented LED control: beware of bugs because there are
  no LEDs on the device I am using!

We do not implement custom DSA tags. This is explained in
a comment in the driver as well: this "tagging protocol" is
not simply a few extra bytes tagged on to the ethernet
frame as DSA is used to. Instead, enabling the CPU tags
will make the switch start talking Realtek RRCP internally.
For example a simple ping will make this kind of packets
appear inside the switch:

0000   ff ff ff ff ff ff bc ae c5 6b a8 3d 88 99 a2 00
0010   08 06 00 01 08 00 06 04 00 01 bc ae c5 6b a8 3d
0020   a9 fe 01 01 00 00 00 00 00 00 a9 fe 01 02 00 00
0030   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

As you can see a custom "8899" tagged packet using the
protocol 0xa2. Norm RRCP appears to always have this
protocol set to 0x01 according to OpenRRCP. You can also
see that this is not a ping packet at all, instead the
switch is starting to talk network management issues
with the CPU port.

So for now custom "tagging" is disabled.

This was tested on the D-Link DIR-685 with initramfs and
OpenWRT userspaces and works fine on all the LAN ports
(lan0 .. lan3). The WAN port is yet not working.

Cc: Antti Seppälä <a.seppala@gmail.com>
Cc: Roman Yeryomin <roman@advem.lv>
Cc: Colin Leitner <colin.leitner@googlemail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 516 insertions, 0 deletions

diff --git a/drivers/net/dsa/rtl8366.c b/drivers/net/dsa/rtl8366.c
new file mode 100644
index 000000000000..58d8534f7ecb
--- /dev/null
+++ b/drivers/net/dsa/rtl8366.c
@@ -0,0 +1,516 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Realtek SMI library helpers for the RTL8366x variants
+ * RTL8366RB and RTL8366S
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2010 Antti Seppälä <a.seppala@gmail.com>
+ * Copyright (C) 2010 Roman Yeryomin <roman@advem.lv>
+ * Copyright (C) 2011 Colin Leitner <colin.leitner@googlemail.com>
+ */
+#include <linux/if_bridge.h>
+#include <net/dsa.h>
+
+#include "realtek-smi.h"
+
+int rtl8366_mc_is_used(struct realtek_smi *smi, int mc_index, int *used)
+{
+	int ret;
+	int i;
+
+	*used = 0;
+	for (i = 0; i < smi->num_ports; i++) {
+		int index = 0;
+
+		ret = smi->ops->get_mc_index(smi, i, &index);
+		if (ret)
+			return ret;
+
+		if (mc_index == index) {
+			*used = 1;
+			break;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_mc_is_used);
+
+int rtl8366_set_vlan(struct realtek_smi *smi, int vid, u32 member,
+		     u32 untag, u32 fid)
+{
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	/* Update the 4K table */
+	ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+	if (ret)
+		return ret;
+
+	vlan4k.member = member;
+	vlan4k.untag = untag;
+	vlan4k.fid = fid;
+	ret = smi->ops->set_vlan_4k(smi, &vlan4k);
+	if (ret)
+		return ret;
+
+	/* Try to find an existing MC entry for this VID */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		struct rtl8366_vlan_mc vlanmc;
+
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vid == vlanmc.vid) {
+			/* update the MC entry */
+			vlanmc.member = member;
+			vlanmc.untag = untag;
+			vlanmc.fid = fid;
+
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_set_vlan);
+
+int rtl8366_get_pvid(struct realtek_smi *smi, int port, int *val)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	int ret;
+	int index;
+
+	ret = smi->ops->get_mc_index(smi, port, &index);
+	if (ret)
+		return ret;
+
+	ret = smi->ops->get_vlan_mc(smi, index, &vlanmc);
+	if (ret)
+		return ret;
+
+	*val = vlanmc.vid;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_pvid);
+
+int rtl8366_set_pvid(struct realtek_smi *smi, unsigned int port,
+		     unsigned int vid)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	/* Try to find an existing MC entry for this VID */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vid == vlanmc.vid) {
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	/* We have no MC entry for this VID, try to find an empty one */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+
+		if (vlanmc.vid == 0 && vlanmc.member == 0) {
+			/* Update the entry from the 4K table */
+			ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+			if (ret)
+				return ret;
+
+			vlanmc.vid = vid;
+			vlanmc.member = vlan4k.member;
+			vlanmc.untag = vlan4k.untag;
+			vlanmc.fid = vlan4k.fid;
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	/* MC table is full, try to find an unused entry and replace it */
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		int used;
+
+		ret = rtl8366_mc_is_used(smi, i, &used);
+		if (ret)
+			return ret;
+
+		if (!used) {
+			/* Update the entry from the 4K table */
+			ret = smi->ops->get_vlan_4k(smi, vid, &vlan4k);
+			if (ret)
+				return ret;
+
+			vlanmc.vid = vid;
+			vlanmc.member = vlan4k.member;
+			vlanmc.untag = vlan4k.untag;
+			vlanmc.fid = vlan4k.fid;
+			ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			ret = smi->ops->set_mc_index(smi, port, i);
+			return ret;
+		}
+	}
+
+	dev_err(smi->dev,
+		"all VLAN member configurations are in use\n");
+
+	return -ENOSPC;
+}
+EXPORT_SYMBOL_GPL(rtl8366_set_pvid);
+
+int rtl8366_enable_vlan4k(struct realtek_smi *smi, bool enable)
+{
+	int ret;
+
+	/* To enable 4k VLAN, ordinary VLAN must be enabled first,
+	 * but if we disable 4k VLAN it is fine to leave ordinary
+	 * VLAN enabled.
+	 */
+	if (enable) {
+		/* Make sure VLAN is ON */
+		ret = smi->ops->enable_vlan(smi, true);
+		if (ret)
+			return ret;
+
+		smi->vlan_enabled = true;
+	}
+
+	ret = smi->ops->enable_vlan4k(smi, enable);
+	if (ret)
+		return ret;
+
+	smi->vlan4k_enabled = enable;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_enable_vlan4k);
+
+int rtl8366_enable_vlan(struct realtek_smi *smi, bool enable)
+{
+	int ret;
+
+	ret = smi->ops->enable_vlan(smi, enable);
+	if (ret)
+		return ret;
+
+	smi->vlan_enabled = enable;
+
+	/* If we turn VLAN off, make sure that we turn off
+	 * 4k VLAN as well, if that happened to be on.
+	 */
+	if (!enable) {
+		smi->vlan4k_enabled = false;
+		ret = smi->ops->enable_vlan4k(smi, false);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_enable_vlan);
+
+int rtl8366_reset_vlan(struct realtek_smi *smi)
+{
+	struct rtl8366_vlan_mc vlanmc;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+	int i;
+
+	rtl8366_enable_vlan(smi, false);
+	rtl8366_enable_vlan4k(smi, false);
+
+	/* Clear the 16 VLAN member configurations */
+	vlanmc.vid = 0;
+	vlanmc.priority = 0;
+	vlanmc.member = 0;
+	vlanmc.untag = 0;
+	vlanmc.fid = 0;
+	for (i = 0; i < smi->num_vlan_mc; i++) {
+		ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_reset_vlan);
+
+int rtl8366_init_vlan(struct realtek_smi *smi)
+{
+	int port;
+	int ret;
+
+	ret = rtl8366_reset_vlan(smi);
+	if (ret)
+		return ret;
+
+	/* Loop over the available ports, for each port, associate
+	 * it with the VLAN (port+1)
+	 */
+	for (port = 0; port < smi->num_ports; port++) {
+		u32 mask;
+
+		if (port == smi->cpu_port)
+			/* For the CPU port, make all ports members of this
+			 * VLAN.
+			 */
+			mask = GENMASK(smi->num_ports - 1, 0);
+		else
+			/* For all other ports, enable itself plus the
+			 * CPU port.
+			 */
+			mask = BIT(port) | BIT(smi->cpu_port);
+
+		/* For each port, set the port as member of VLAN (port+1)
+		 * and untagged, except for the CPU port: the CPU port (5) is
+		 * member of VLAN 6 and so are ALL the other ports as well.
+		 * Use filter 0 (no filter).
+		 */
+		dev_info(smi->dev, "VLAN%d port mask for port %d, %08x\n",
+			 (port + 1), port, mask);
+		ret = rtl8366_set_vlan(smi, (port + 1), mask, mask, 0);
+		if (ret)
+			return ret;
+
+		dev_info(smi->dev, "VLAN%d port %d, PVID set to %d\n",
+			 (port + 1), port, (port + 1));
+		ret = rtl8366_set_pvid(smi, port, (port + 1));
+		if (ret)
+			return ret;
+	}
+
+	return rtl8366_enable_vlan(smi, true);
+}
+EXPORT_SYMBOL_GPL(rtl8366_init_vlan);
+
+int rtl8366_vlan_filtering(struct dsa_switch *ds, int port, bool vlan_filtering)
+{
+	struct realtek_smi *smi = ds->priv;
+	struct rtl8366_vlan_4k vlan4k;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return -EINVAL;
+
+	dev_info(smi->dev, "%s filtering on port %d\n",
+		 vlan_filtering ? "enable" : "disable",
+		 port);
+
+	/* TODO:
+	 * The hardware support filter ID (FID) 0..7, I have no clue how to
+	 * support this in the driver when the callback only says on/off.
+	 */
+	ret = smi->ops->get_vlan_4k(smi, port, &vlan4k);
+	if (ret)
+		return ret;
+
+	/* Just set the filter to FID 1 for now then */
+	ret = rtl8366_set_vlan(smi, port,
+			       vlan4k.member,
+			       vlan4k.untag,
+			       1);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_filtering);
+
+int rtl8366_vlan_prepare(struct dsa_switch *ds, int port,
+			 const struct switchdev_obj_port_vlan *vlan)
+{
+	struct realtek_smi *smi = ds->priv;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return -EINVAL;
+
+	dev_info(smi->dev, "prepare VLANs %04x..%04x\n",
+		 vlan->vid_begin, vlan->vid_end);
+
+	/* Enable VLAN in the hardware
+	 * FIXME: what's with this 4k business?
+	 * Just rtl8366_enable_vlan() seems inconclusive.
+	 */
+	ret = rtl8366_enable_vlan4k(smi, true);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_prepare);
+
+void rtl8366_vlan_add(struct dsa_switch *ds, int port,
+		      const struct switchdev_obj_port_vlan *vlan)
+{
+	bool untagged = !!(vlan->flags & BRIDGE_VLAN_INFO_UNTAGGED);
+	bool pvid = !!(vlan->flags & BRIDGE_VLAN_INFO_PVID);
+	struct realtek_smi *smi = ds->priv;
+	u32 member = 0;
+	u32 untag = 0;
+	u16 vid;
+	int ret;
+
+	if (!smi->ops->is_vlan_valid(smi, port))
+		return;
+
+	dev_info(smi->dev, "add VLAN on port %d, %s, %s\n",
+		 port,
+		 untagged ? "untagged" : "tagged",
+		 pvid ? " PVID" : "no PVID");
+
+	if (dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port))
+		dev_err(smi->dev, "port is DSA or CPU port\n");
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		int pvid_val = 0;
+
+		dev_info(smi->dev, "add VLAN %04x\n", vid);
+		member |= BIT(port);
+
+		if (untagged)
+			untag |= BIT(port);
+
+		/* To ensure that we have a valid MC entry for this VLAN,
+		 * initialize the port VLAN ID here.
+		 */
+		ret = rtl8366_get_pvid(smi, port, &pvid_val);
+		if (ret < 0) {
+			dev_err(smi->dev, "could not lookup PVID for port %d\n",
+				port);
+			return;
+		}
+		if (pvid_val == 0) {
+			ret = rtl8366_set_pvid(smi, port, vid);
+			if (ret < 0)
+				return;
+		}
+	}
+
+	ret = rtl8366_set_vlan(smi, port, member, untag, 0);
+	if (ret)
+		dev_err(smi->dev,
+			"failed to set up VLAN %04x",
+			vid);
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_add);
+
+int rtl8366_vlan_del(struct dsa_switch *ds, int port,
+		     const struct switchdev_obj_port_vlan *vlan)
+{
+	struct realtek_smi *smi = ds->priv;
+	u16 vid;
+	int ret;
+
+	dev_info(smi->dev, "del VLAN on port %d\n", port);
+
+	for (vid = vlan->vid_begin; vid <= vlan->vid_end; ++vid) {
+		int i;
+
+		dev_info(smi->dev, "del VLAN %04x\n", vid);
+
+		for (i = 0; i < smi->num_vlan_mc; i++) {
+			struct rtl8366_vlan_mc vlanmc;
+
+			ret = smi->ops->get_vlan_mc(smi, i, &vlanmc);
+			if (ret)
+				return ret;
+
+			if (vid == vlanmc.vid) {
+				/* clear VLAN member configurations */
+				vlanmc.vid = 0;
+				vlanmc.priority = 0;
+				vlanmc.member = 0;
+				vlanmc.untag = 0;
+				vlanmc.fid = 0;
+
+				ret = smi->ops->set_vlan_mc(smi, i, &vlanmc);
+				if (ret) {
+					dev_err(smi->dev,
+						"failed to remove VLAN %04x\n",
+						vid);
+					return ret;
+				}
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtl8366_vlan_del);
+
+void rtl8366_get_strings(struct dsa_switch *ds, int port, u32 stringset,
+			 uint8_t *data)
+{
+	struct realtek_smi *smi = ds->priv;
+	struct rtl8366_mib_counter *mib;
+	int i;
+
+	if (port >= smi->num_ports)
+		return;
+
+	for (i = 0; i < smi->num_mib_counters; i++) {
+		mib = &smi->mib_counters[i];
+		strncpy(data + i * ETH_GSTRING_LEN,
+			mib->name, ETH_GSTRING_LEN);
+	}
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_strings);
+
+int rtl8366_get_sset_count(struct dsa_switch *ds, int port, int sset)
+{
+	struct realtek_smi *smi = ds->priv;
+
+	/* We only support SS_STATS */
+	if (sset != ETH_SS_STATS)
+		return 0;
+	if (port >= smi->num_ports)
+		return -EINVAL;
+
+	return smi->num_mib_counters;
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_sset_count);
+
+void rtl8366_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
+{
+	struct realtek_smi *smi = ds->priv;
+	int i;
+	int ret;
+
+	if (port >= smi->num_ports)
+		return;
+
+	for (i = 0; i < smi->num_mib_counters; i++) {
+		struct rtl8366_mib_counter *mib;
+		u64 mibvalue = 0;
+
+		mib = &smi->mib_counters[i];
+		ret = smi->ops->get_mib_counter(smi, port, mib, &mibvalue);
+		if (ret) {
+			dev_err(smi->dev, "error reading MIB counter %s\n",
+				mib->name);
+		}
+		data[i] = mibvalue;
+	}
+}
+EXPORT_SYMBOL_GPL(rtl8366_get_ethtool_stats);