phy: Add support for the NC-SI protocol

This introduces support for the NC-SI protocol, modelled as a phy driver
for other ethernet drivers to consume.

NC-SI (Network Controller Sideband Interface) is a protocol to manage a
sideband connection to a proper network interface, for example a BMC
(Baseboard Management Controller) sharing the NIC of the host system.
Probing and configuration occurs by communicating with the "remote" NIC
via NC-SI control frames (Ethernet header 0x88f8).

This implementation is roughly based on the upstream Linux
implementation[0], with a reduced feature set and an emphasis on getting
a link up as fast as possible rather than probing the full possible
topology of the bus.
The current phy model relies on the network being "up", sending NC-SI
command frames via net_send_packet() and receiving them from the
net_loop() loop (added in a following patch).

The ncsi-pkt.h header[1] is copied from the Linux kernel for consistent
field definitions.

[0]: https://github.com/torvalds/linux/tree/master/net/ncsi
[1]: https://github.com/torvalds/linux/blob/master/net/ncsi/ncsi-pkt.h

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

3 files changed, 902 insertions, 0 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index dceea15..d1f049e 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -267,4 +267,8 @@ config PHY_FIXED
 	  on, the link is always up with fixed speed and fixed duplex-setting.
 	  More information: doc/device-tree-bindings/net/fixed-link.txt
 
+config PHY_NCSI
+	bool "NC-SI based PHY"
+	depends on DM_ETH
+
 endif #PHYLIB
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 78955c5..1d81516 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -31,3 +31,4 @@ obj-$(CONFIG_PHY_XILINX_GMII2RGMII) += xilinx_gmii2rgmii.o
 obj-$(CONFIG_PHY_VITESSE) += vitesse.o
 obj-$(CONFIG_PHY_MSCC) += mscc.o
 obj-$(CONFIG_PHY_FIXED) += fixed.o
+obj-$(CONFIG_PHY_NCSI) += ncsi.o
diff --git a/drivers/net/phy/ncsi.c b/drivers/net/phy/ncsi.c
new file mode 100644
index 0000000..adc3ac0
--- /dev/null
+++ b/drivers/net/phy/ncsi.c
@@ -0,0 +1,897 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NC-SI protocol configuration
+ *
+ * Copyright (C) 2019, IBM Corporation.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <phy.h>
+#include <net/ncsi.h>
+#include <net/ncsi-pkt.h>
+#include <asm/unaligned.h>
+
+#define NCSI_PACKAGE_MAX 8
+#define NCSI_CHANNEL_MAX 31
+
+#define NCSI_PACKAGE_SHIFT      5
+#define NCSI_PACKAGE_INDEX(c)   (((c) >> NCSI_PACKAGE_SHIFT) & 0x7)
+#define NCSI_RESERVED_CHANNEL   0x1f
+#define NCSI_CHANNEL_INDEX(c)   ((c) & ((1 << NCSI_PACKAGE_SHIFT) - 1))
+#define NCSI_TO_CHANNEL(p, c)   (((p) << NCSI_PACKAGE_SHIFT) | (c))
+
+#define NCSI_PKT_REVISION       0x01
+
+#define NCSI_CAP_GENERIC_MASK	0x7f
+#define NCSI_CAP_BC_MASK	0x0f
+#define NCSI_CAP_MC_MASK	0x3f
+#define NCSI_CAP_AEN_MASK	0x07
+#define NCSI_CAP_VLAN_MASK	0x07
+
+static void ncsi_send_ebf(unsigned int np, unsigned int nc);
+static void ncsi_send_ae(unsigned int np, unsigned int nc);
+static void ncsi_send_gls(unsigned int np, unsigned int nc);
+static int ncsi_send_command(unsigned int np, unsigned int nc, unsigned int cmd,
+			     uchar *payload, int len, bool wait);
+
+struct ncsi_channel {
+	unsigned int	id;
+	bool		has_link;
+
+	/* capabilities */
+	u32 cap_generic;
+	u32 cap_bc;
+	u32 cap_mc;
+	u32 cap_buffer;
+	u32 cap_aen;
+	u32 cap_vlan;
+
+	/* version information */
+	struct {
+		u32 version;            /* Supported BCD encoded NCSI version */
+		u32 alpha2;             /* Supported BCD encoded NCSI version */
+		u8  fw_name[12];        /* Firmware name string               */
+		u32 fw_version;         /* Firmware version                   */
+		u16 pci_ids[4];         /* PCI identification                 */
+		u32 mf_id;              /* Manufacture ID                     */
+	} version;
+
+};
+
+struct ncsi_package {
+	unsigned int		id;
+	unsigned int		n_channels;
+	struct ncsi_channel	*channels;
+};
+
+struct ncsi {
+	enum {
+		NCSI_PROBE_PACKAGE_SP,
+		NCSI_PROBE_PACKAGE_DP,
+		NCSI_PROBE_CHANNEL_SP,
+		NCSI_PROBE_CHANNEL,
+		NCSI_CONFIG,
+	} state;
+
+	unsigned int	pending_requests;
+	unsigned int	requests[256];
+	unsigned int	last_request;
+
+	unsigned int	current_package;
+	unsigned int	current_channel;
+
+	unsigned int		n_packages;
+	struct ncsi_package	*packages;
+};
+
+struct ncsi *ncsi_priv;
+
+bool ncsi_active(void)
+{
+	unsigned int np, nc;
+
+	if (!ncsi_priv)
+		return false;
+
+	np = ncsi_priv->current_package;
+	nc = ncsi_priv->current_channel;
+
+	if (ncsi_priv->state != NCSI_CONFIG)
+		return false;
+
+	return np < NCSI_PACKAGE_MAX && nc < NCSI_CHANNEL_MAX &&
+		ncsi_priv->packages[np].channels[nc].has_link;
+}
+
+static unsigned int cmd_payload(int cmd)
+{
+	switch (cmd) {
+	case NCSI_PKT_CMD_CIS:
+		return 0;
+	case NCSI_PKT_CMD_SP:
+		return 4;
+	case NCSI_PKT_CMD_DP:
+		return 0;
+	case NCSI_PKT_CMD_EC:
+		return 0;
+	case NCSI_PKT_CMD_DC:
+		return 4;
+	case NCSI_PKT_CMD_RC:
+		return 4;
+	case NCSI_PKT_CMD_ECNT:
+		return 0;
+	case NCSI_PKT_CMD_DCNT:
+		return 0;
+	case NCSI_PKT_CMD_AE:
+		return 8;
+	case NCSI_PKT_CMD_SL:
+		return 8;
+	case NCSI_PKT_CMD_GLS:
+		return 0;
+	case NCSI_PKT_CMD_SVF:
+		return 8;
+	case NCSI_PKT_CMD_EV:
+		return 4;
+	case NCSI_PKT_CMD_DV:
+		return 0;
+	case NCSI_PKT_CMD_SMA:
+		return 8;
+	case NCSI_PKT_CMD_EBF:
+		return 4;
+	case NCSI_PKT_CMD_DBF:
+		return 0;
+	case NCSI_PKT_CMD_EGMF:
+		return 4;
+	case NCSI_PKT_CMD_DGMF:
+		return 0;
+	case NCSI_PKT_CMD_SNFC:
+		return 4;
+	case NCSI_PKT_CMD_GVI:
+		return 0;
+	case NCSI_PKT_CMD_GC:
+		return 0;
+	case NCSI_PKT_CMD_GP:
+		return 0;
+	case NCSI_PKT_CMD_GCPS:
+		return 0;
+	case NCSI_PKT_CMD_GNS:
+		return 0;
+	case NCSI_PKT_CMD_GNPTS:
+		return 0;
+	case NCSI_PKT_CMD_GPS:
+		return 0;
+	default:
+		printf("NCSI: Unknown command 0x%02x\n", cmd);
+		return 0;
+	}
+}
+
+static u32 ncsi_calculate_checksum(unsigned char *data, int len)
+{
+	u32 checksum = 0;
+	int i;
+
+	for (i = 0; i < len; i += 2)
+		checksum += (((u32)data[i] << 8) | data[i + 1]);
+
+	checksum = (~checksum + 1);
+	return checksum;
+}
+
+static int ncsi_validate_rsp(struct ncsi_rsp_pkt *pkt, int payload)
+{
+	struct ncsi_rsp_pkt_hdr *hdr = &pkt->rsp;
+	u32 checksum, c_offset;
+	__be32 pchecksum;
+
+	if (hdr->common.revision != 1) {
+		printf("NCSI: 0x%02x response has unsupported revision 0x%x\n",
+		       hdr->common.type, hdr->common.revision);
+		return -1;
+	}
+
+	if (hdr->code != 0) {
+		printf("NCSI: 0x%02x response returns error %d\n",
+		       hdr->common.type, __be16_to_cpu(hdr->code));
+		if (ntohs(hdr->reason) == 0x05)
+			printf("(Invalid command length)\n");
+		return -1;
+	}
+
+	if (ntohs(hdr->common.length) != payload) {
+		printf("NCSI: 0x%02x response has incorrect length %d\n",
+		       hdr->common.type, hdr->common.length);
+		return -1;
+	}
+
+	c_offset = sizeof(struct ncsi_rsp_pkt_hdr) + payload - sizeof(checksum);
+	pchecksum = get_unaligned_be32((void *)hdr + c_offset);
+	if (pchecksum != 0) {
+		checksum = ncsi_calculate_checksum((unsigned char *)hdr,
+						   c_offset);
+		if (pchecksum != checksum) {
+			printf("NCSI: 0x%02x response has invalid checksum\n",
+			       hdr->common.type);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static void ncsi_rsp_ec(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&pkt->rsp;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	if (ncsi_priv->packages[np].channels[nc].cap_aen != 0)
+		ncsi_send_ae(np, nc);
+	/* else, done */
+}
+
+static void ncsi_rsp_ecnt(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&pkt->rsp;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_EC, NULL, 0, true);
+}
+
+static void ncsi_rsp_ebf(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&pkt->rsp;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_ECNT, NULL, 0, true);
+}
+
+static void ncsi_rsp_sma(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&pkt->rsp;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	ncsi_send_ebf(np, nc);
+}
+
+static void ncsi_rsp_gc(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_gc_pkt *gc = (struct ncsi_rsp_gc_pkt *)pkt;
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&gc->rsp;
+	struct ncsi_channel *c;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	if (np >= ncsi_priv->n_packages ||
+	    nc >= ncsi_priv->packages[np].n_channels) {
+		printf("NCSI: Invalid package / channel (0x%02x, 0x%02x)\n",
+		       np, nc);
+		return;
+	}
+
+	c = &ncsi_priv->packages[np].channels[nc];
+	c->cap_generic = ntohl(gc->cap) & NCSI_CAP_GENERIC_MASK;
+	c->cap_bc = ntohl(gc->bc_cap) & NCSI_CAP_BC_MASK;
+	c->cap_mc = ntohl(gc->mc_cap) & NCSI_CAP_MC_MASK;
+	c->cap_aen = ntohl(gc->aen_cap) & NCSI_CAP_AEN_MASK;
+	c->cap_vlan = ntohl(gc->vlan_mode) & NCSI_CAP_VLAN_MASK;
+
+	/* End of probe for this channel */
+}
+
+static void ncsi_rsp_gvi(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_gvi_pkt *gvi = (struct ncsi_rsp_gvi_pkt *)pkt;
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&gvi->rsp;
+	struct ncsi_channel *c;
+	unsigned int np, nc, i;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	if (np >= ncsi_priv->n_packages ||
+	    nc >= ncsi_priv->packages[np].n_channels) {
+		printf("NCSI: Invalid package / channel (0x%02x, 0x%02x)\n",
+		       np, nc);
+		return;
+	}
+
+	c = &ncsi_priv->packages[np].channels[nc];
+	c->version.version = get_unaligned_be32(&gvi->ncsi_version);
+	c->version.alpha2 = gvi->alpha2;
+	memcpy(c->version.fw_name, gvi->fw_name, sizeof(c->version.fw_name));
+	c->version.fw_version = get_unaligned_be32(&gvi->fw_version);
+	for (i = 0; i < ARRAY_SIZE(c->version.pci_ids); i++)
+		c->version.pci_ids[i] = get_unaligned_be16(gvi->pci_ids + i);
+	c->version.mf_id = get_unaligned_be32(&gvi->mf_id);
+
+	if (ncsi_priv->state == NCSI_PROBE_CHANNEL)
+		ncsi_send_command(np, nc, NCSI_PKT_CMD_GC, NULL, 0, true);
+}
+
+static void ncsi_rsp_gls(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_gls_pkt *gls = (struct ncsi_rsp_gls_pkt *)pkt;
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)&gls->rsp;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	if (np >= ncsi_priv->n_packages ||
+	    nc >= ncsi_priv->packages[np].n_channels) {
+		printf("NCSI: Invalid package / channel (0x%02x, 0x%02x)\n",
+		       np, nc);
+		return;
+	}
+
+	ncsi_priv->packages[np].channels[nc].has_link =
+					!!(get_unaligned_be32(&gls->status));
+
+	if (ncsi_priv->state == NCSI_PROBE_CHANNEL)
+		ncsi_send_command(np, nc, NCSI_PKT_CMD_GVI, NULL, 0, true);
+}
+
+static void ncsi_rsp_cis(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)pkt;
+	struct ncsi_package *package;
+	unsigned int np, nc;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	nc = NCSI_CHANNEL_INDEX(rsp->common.channel);
+
+	if (np >= ncsi_priv->n_packages) {
+		printf("NCSI: Mystery package 0x%02x from CIS\n", np);
+		return;
+	}
+
+	package = &ncsi_priv->packages[np];
+
+	if (nc < package->n_channels) {
+		/*
+		 * This is fine in general but in the current design we
+		 * don't send CIS commands to known channels.
+		 */
+		debug("NCSI: Duplicate channel 0x%02x\n", nc);
+		return;
+	}
+
+	package->channels = realloc(package->channels,
+				    sizeof(struct ncsi_channel) *
+				    (package->n_channels + 1));
+	if (!package->channels) {
+		printf("NCSI: Could not allocate memory for new channel\n");
+		return;
+	}
+
+	debug("NCSI: New channel 0x%02x\n", nc);
+
+	package->channels[nc].id = nc;
+	package->channels[nc].has_link = false;
+	package->n_channels++;
+
+	ncsi_send_gls(np, nc);
+}
+
+static void ncsi_rsp_dp(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)pkt;
+	unsigned int np;
+
+	/* No action needed */
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+	if (np >= ncsi_priv->n_packages)
+		debug("NCSI: DP response from unknown package %d\n", np);
+}
+
+static void ncsi_rsp_sp(struct ncsi_rsp_pkt *pkt)
+{
+	struct ncsi_rsp_pkt_hdr *rsp = (struct ncsi_rsp_pkt_hdr *)pkt;
+	unsigned int np;
+
+	np = NCSI_PACKAGE_INDEX(rsp->common.channel);
+
+	if (np < ncsi_priv->n_packages) {
+		/* Already know about this package */
+		debug("NCSI: package 0x%02x selected\n", np);
+		return;
+	}
+
+	debug("NCSI: adding new package %d\n", np);
+
+	ncsi_priv->packages = realloc(ncsi_priv->packages,
+				      sizeof(struct ncsi_package) *
+				      (ncsi_priv->n_packages + 1));
+	if (!ncsi_priv->packages) {
+		printf("NCSI: could not allocate memory for new package\n");
+		return;
+	}
+
+	ncsi_priv->packages[np].id = np;
+	ncsi_priv->packages[np].n_channels = 0;
+	ncsi_priv->packages[np].channels = NULL;
+	ncsi_priv->n_packages++;
+}
+
+static void ncsi_update_state(struct ncsi_rsp_pkt_hdr *nh)
+{
+	bool timeout = !nh;
+	int np, nc;
+
+	switch (ncsi_priv->state) {
+	case NCSI_PROBE_PACKAGE_SP:
+		if (!timeout &&
+		    ncsi_priv->current_package + 1 < NCSI_PACKAGE_MAX) {
+			ncsi_priv->current_package++;
+		} else {
+			ncsi_priv->state = NCSI_PROBE_PACKAGE_DP;
+			ncsi_priv->current_package = 0;
+		}
+		return ncsi_probe_packages();
+	case NCSI_PROBE_PACKAGE_DP:
+		if (ncsi_priv->current_package + 1 < ncsi_priv->n_packages &&
+		    !timeout) {
+			ncsi_priv->current_package++;
+		} else {
+			if (!ncsi_priv->n_packages) {
+				printf("NCSI: no packages found\n");
+				net_set_state(NETLOOP_FAIL);
+				return;
+			}
+			printf("NCSI: probing channels\n");
+			ncsi_priv->state = NCSI_PROBE_CHANNEL_SP;
+			ncsi_priv->current_package = 0;
+			ncsi_priv->current_channel = 0;
+		}
+		return ncsi_probe_packages();
+	case NCSI_PROBE_CHANNEL_SP:
+		if (!timeout && nh->common.type == NCSI_PKT_RSP_SP) {
+			ncsi_priv->state = NCSI_PROBE_CHANNEL;
+			return ncsi_probe_packages();
+		}
+		printf("NCSI: failed to select package 0x%0x2 or timeout\n",
+		       ncsi_priv->current_package);
+		net_set_state(NETLOOP_FAIL);
+		break;
+	case NCSI_PROBE_CHANNEL:
+		// TODO only does package 0 for now
+		if (ncsi_priv->pending_requests == 0) {
+			np = ncsi_priv->current_package;
+			nc = ncsi_priv->current_channel;
+
+			/* Configure first channel that has link */
+			if (ncsi_priv->packages[np].channels[nc].has_link) {
+				ncsi_priv->state = NCSI_CONFIG;
+			} else if (ncsi_priv->current_channel + 1 <
+				   NCSI_CHANNEL_MAX) {
+				ncsi_priv->current_channel++;
+			} else {
+				// XXX As above only package 0
+				printf("NCSI: no channel found with link\n");
+				net_set_state(NETLOOP_FAIL);
+				return;
+			}
+			return ncsi_probe_packages();
+		}
+		break;
+	case NCSI_CONFIG:
+		if (ncsi_priv->pending_requests == 0) {
+			printf("NCSI: configuration done!\n");
+			net_set_state(NETLOOP_SUCCESS);
+		} else if (timeout) {
+			printf("NCSI: timeout during configure\n");
+			net_set_state(NETLOOP_FAIL);
+		}
+		break;
+	default:
+		printf("NCSI: something went very wrong, nevermind\n");
+		net_set_state(NETLOOP_FAIL);
+		break;
+	}
+}
+
+static void ncsi_timeout_handler(void)
+{
+	if (ncsi_priv->pending_requests)
+		ncsi_priv->pending_requests--;
+
+	ncsi_update_state(NULL);
+}
+
+static int ncsi_send_command(unsigned int np, unsigned int nc, unsigned int cmd,
+			     uchar *payload, int len, bool wait)
+{
+	struct ncsi_pkt_hdr *hdr;
+	__be32 *pchecksum;
+	int eth_hdr_size;
+	u32 checksum;
+	uchar *pkt, *start;
+	int final_len;
+
+	pkt = calloc(1, PKTSIZE_ALIGN + PKTALIGN);
+	if (!pkt)
+		return -ENOMEM;
+	start = pkt;
+
+	eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_NCSI);
+	pkt += eth_hdr_size;
+
+	/* Set NCSI command header fields */
+	hdr = (struct ncsi_pkt_hdr *)pkt;
+	hdr->mc_id = 0;
+	hdr->revision = NCSI_PKT_REVISION;
+	hdr->id = ++ncsi_priv->last_request;
+	ncsi_priv->requests[ncsi_priv->last_request] = 1;
+	hdr->type = cmd;
+	hdr->channel = NCSI_TO_CHANNEL(np, nc);
+	hdr->length = htons(len);
+
+	if (payload && len)
+		memcpy(pkt + sizeof(struct ncsi_pkt_hdr), payload, len);
+
+	/* Calculate checksum */
+	checksum = ncsi_calculate_checksum((unsigned char *)hdr,
+					   sizeof(*hdr) + len);
+	pchecksum = (__be32 *)((void *)(hdr + 1) + len);
+	put_unaligned_be32(htonl(checksum), pchecksum);
+
+	if (wait) {
+		net_set_timeout_handler(1000UL, ncsi_timeout_handler);
+		ncsi_priv->pending_requests++;
+	}
+
+	if (len < 26)
+		len = 26;
+	/* frame header, packet header, payload, checksum */
+	final_len = eth_hdr_size + sizeof(struct ncsi_cmd_pkt_hdr) + len + 4;
+
+	net_send_packet(start, final_len);
+	free(start);
+	return 0;
+}
+
+static void ncsi_handle_aen(struct ip_udp_hdr *ip, unsigned int len)
+{
+	struct ncsi_aen_pkt_hdr *hdr = (struct ncsi_aen_pkt_hdr *)ip;
+	int payload, i;
+	__be32 pchecksum;
+	u32 checksum;
+
+	switch (hdr->type) {
+	case NCSI_PKT_AEN_LSC:
+		printf("NCSI: link state changed\n");
+		payload = 12;
+		break;
+	case NCSI_PKT_AEN_CR:
+		printf("NCSI: re-configuration required\n");
+		payload = 4;
+		break;
+	case NCSI_PKT_AEN_HNCDSC:
+		/* Host notifcation - N/A but weird */
+		debug("NCSI: HNCDSC AEN received\n");
+		return;
+	default:
+		printf("%s: Invalid type 0x%02x\n", __func__, hdr->type);
+		return;
+	}
+
+	/* Validate packet */
+	if (hdr->common.revision != 1) {
+		printf("NCSI: 0x%02x response has unsupported revision 0x%x\n",
+		       hdr->common.type, hdr->common.revision);
+		return;
+	}
+
+	if (ntohs(hdr->common.length) != payload) {
+		printf("NCSI: 0x%02x response has incorrect length %d\n",
+		       hdr->common.type, hdr->common.length);
+		return;
+	}
+
+	pchecksum = get_unaligned_be32((void *)(hdr + 1) + payload - 4);
+	if (pchecksum != 0) {
+		checksum = ncsi_calculate_checksum((unsigned char *)hdr,
+						   sizeof(*hdr) + payload - 4);
+		if (pchecksum != checksum) {
+			printf("NCSI: 0x%02x response has invalid checksum\n",
+			       hdr->common.type);
+			return;
+		}
+	}
+
+	/* Link or configuration lost - just redo the discovery process */
+	ncsi_priv->state = NCSI_PROBE_PACKAGE_SP;
+	for (i = 0; i < ncsi_priv->n_packages; i++)
+		free(ncsi_priv->packages[i].channels);
+	free(ncsi_priv->packages);
+	ncsi_priv->n_packages = 0;
+
+	ncsi_priv->current_package = NCSI_PACKAGE_MAX;
+	ncsi_priv->current_channel = NCSI_CHANNEL_MAX;
+
+	ncsi_probe_packages();
+}
+
+void ncsi_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip,
+		  unsigned int len)
+{
+	struct ncsi_rsp_pkt *pkt = (struct ncsi_rsp_pkt *)ip;
+	struct ncsi_rsp_pkt_hdr *nh = (struct ncsi_rsp_pkt_hdr *)&pkt->rsp;
+	void (*handler)(struct ncsi_rsp_pkt *pkt) = NULL;
+	unsigned short payload;
+
+	if (ncsi_priv->pending_requests)
+		ncsi_priv->pending_requests--;
+
+	if (len < sizeof(struct ncsi_rsp_pkt_hdr)) {
+		printf("NCSI: undersized packet: %u bytes\n", len);
+		goto out;
+	}
+
+	if (nh->common.type == NCSI_PKT_AEN)
+		return ncsi_handle_aen(ip, len);
+
+	switch (nh->common.type) {
+	case NCSI_PKT_RSP_SP:
+		payload = 4;
+		handler = ncsi_rsp_sp;
+		break;
+	case NCSI_PKT_RSP_DP:
+		payload = 4;
+		handler = ncsi_rsp_dp;
+		break;
+	case NCSI_PKT_RSP_CIS:
+		payload = 4;
+		handler = ncsi_rsp_cis;
+		break;
+	case NCSI_PKT_RSP_GLS:
+		payload = 16;
+		handler = ncsi_rsp_gls;
+		break;
+	case NCSI_PKT_RSP_GVI:
+		payload = 40;
+		handler = ncsi_rsp_gvi;
+		break;
+	case NCSI_PKT_RSP_GC:
+		payload = 32;
+		handler = ncsi_rsp_gc;
+		break;
+	case NCSI_PKT_RSP_SMA:
+		payload = 4;
+		handler = ncsi_rsp_sma;
+		break;
+	case NCSI_PKT_RSP_EBF:
+		payload = 4;
+		handler = ncsi_rsp_ebf;
+		break;
+	case NCSI_PKT_RSP_ECNT:
+		payload = 4;
+		handler = ncsi_rsp_ecnt;
+		break;
+	case NCSI_PKT_RSP_EC:
+		payload = 4;
+		handler = ncsi_rsp_ec;
+		break;
+	case NCSI_PKT_RSP_AE:
+		payload = 4;
+		handler = NULL;
+		break;
+	default:
+		printf("NCSI: unsupported packet type 0x%02x\n",
+		       nh->common.type);
+		goto out;
+	}
+
+	if (ncsi_validate_rsp(pkt, payload) != 0) {
+		printf("NCSI: discarding invalid packet of type 0x%02x\n",
+		       nh->common.type);
+		goto out;
+	}
+
+	if (handler)
+		handler(pkt);
+out:
+	ncsi_update_state(nh);
+}
+
+static void ncsi_send_sp(unsigned int np)
+{
+	uchar payload[4] = {0};
+
+	ncsi_send_command(np, NCSI_RESERVED_CHANNEL, NCSI_PKT_CMD_SP,
+			  (unsigned char *)&payload,
+			  cmd_payload(NCSI_PKT_CMD_SP), true);
+}
+
+static void ncsi_send_dp(unsigned int np)
+{
+	ncsi_send_command(np, NCSI_RESERVED_CHANNEL, NCSI_PKT_CMD_DP, NULL, 0,
+			  true);
+}
+
+static void ncsi_send_gls(unsigned int np, unsigned int nc)
+{
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_GLS, NULL, 0, true);
+}
+
+static void ncsi_send_cis(unsigned int np, unsigned int nc)
+{
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_CIS, NULL, 0, true);
+}
+
+static void ncsi_send_ae(unsigned int np, unsigned int nc)
+{
+	struct ncsi_cmd_ae_pkt cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.mode = htonl(ncsi_priv->packages[np].channels[nc].cap_aen);
+
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_AE,
+			  ((unsigned char *)&cmd)
+			  + sizeof(struct ncsi_cmd_pkt_hdr),
+			  cmd_payload(NCSI_PKT_CMD_AE), true);
+}
+
+static void ncsi_send_ebf(unsigned int np, unsigned int nc)
+{
+	struct ncsi_cmd_ebf_pkt cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.mode = htonl(ncsi_priv->packages[np].channels[nc].cap_bc);
+
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_EBF,
+			  ((unsigned char *)&cmd)
+			  + sizeof(struct ncsi_cmd_pkt_hdr),
+			  cmd_payload(NCSI_PKT_CMD_EBF), true);
+}
+
+static void ncsi_send_sma(unsigned int np, unsigned int nc)
+{
+	struct ncsi_cmd_sma_pkt cmd;
+	unsigned char *addr, i;
+
+	addr = eth_get_ethaddr();
+	if (!addr) {
+		printf("NCSI: no MAC address configured\n");
+		return;
+	}
+
+	memset(&cmd, 0, sizeof(cmd));
+	for (i = 0; i < ARP_HLEN; i++)
+		cmd.mac[i] = addr[i];
+	cmd.index = 1;
+	cmd.at_e = 1;
+
+	ncsi_send_command(np, nc, NCSI_PKT_CMD_SMA,
+			  ((unsigned char *)&cmd)
+			  + sizeof(struct ncsi_cmd_pkt_hdr),
+			  cmd_payload(NCSI_PKT_CMD_SMA), true);
+}
+
+void ncsi_probe_packages(void)
+{
+	struct ncsi_package *package;
+	unsigned int np, nc;
+
+	switch (ncsi_priv->state) {
+	case NCSI_PROBE_PACKAGE_SP:
+		if (ncsi_priv->current_package == NCSI_PACKAGE_MAX)
+			ncsi_priv->current_package = 0;
+		ncsi_send_sp(ncsi_priv->current_package);
+		break;
+	case NCSI_PROBE_PACKAGE_DP:
+		ncsi_send_dp(ncsi_priv->current_package);
+		break;
+	case NCSI_PROBE_CHANNEL_SP:
+		if (ncsi_priv->n_packages > 0)
+			ncsi_send_sp(ncsi_priv->current_package);
+		else
+			printf("NCSI: no packages discovered, configuration not possible\n");
+		break;
+	case NCSI_PROBE_CHANNEL:
+		/* Kicks off chain of channel discovery */
+		ncsi_send_cis(ncsi_priv->current_package,
+			      ncsi_priv->current_channel);
+		break;
+	case NCSI_CONFIG:
+		for (np = 0; np < ncsi_priv->n_packages; np++) {
+			package = &ncsi_priv->packages[np];
+			for (nc = 0; nc < package->n_channels; nc++)
+				if (package->channels[nc].has_link)
+					break;
+			if (nc < package->n_channels)
+				break;
+		}
+		if (np == ncsi_priv->n_packages) {
+			printf("NCSI: no link available\n");
+			return;
+		}
+
+		printf("NCSI: configuring channel %d\n", nc);
+		ncsi_priv->current_package = np;
+		ncsi_priv->current_channel = nc;
+		/* Kicks off rest of configure chain */
+		ncsi_send_sma(np, nc);
+		break;
+	default:
+		printf("NCSI: unknown state 0x%x\n", ncsi_priv->state);
+	}
+}
+
+int ncsi_probe(struct phy_device *phydev)
+{
+	if (!phydev->priv) {
+		phydev->priv = malloc(sizeof(struct ncsi));
+		if (!phydev->priv)
+			return -ENOMEM;
+		memset(phydev->priv, 0, sizeof(struct ncsi));
+	}
+
+	ncsi_priv = phydev->priv;
+
+	return 0;
+}
+
+int ncsi_startup(struct phy_device *phydev)
+{
+	/* Set phydev parameters */
+	phydev->speed = SPEED_100;
+	phydev->duplex = DUPLEX_FULL;
+	/* Normal phy reset is N/A */
+	phydev->flags |= PHY_FLAG_BROKEN_RESET;
+
+	/* Set initial probe state */
+	ncsi_priv->state = NCSI_PROBE_PACKAGE_SP;
+
+	/* No active package/channel yet */
+	ncsi_priv->current_package = NCSI_PACKAGE_MAX;
+	ncsi_priv->current_channel = NCSI_CHANNEL_MAX;
+
+	/* Pretend link works so the MAC driver sets final bits up */
+	phydev->link = true;
+
+	/* Set ncsi_priv so we can use it when called from net_loop() */
+	ncsi_priv = phydev->priv;
+
+	return 0;
+}
+
+int ncsi_shutdown(struct phy_device *phydev)
+{
+	printf("NCSI: Disabling package %d\n", ncsi_priv->current_package);
+	ncsi_send_dp(ncsi_priv->current_package);
+	return 0;
+}
+
+static struct phy_driver ncsi_driver = {
+	.uid		= PHY_NCSI_ID,
+	.mask		= 0xffffffff,
+	.name		= "NC-SI",
+	.features	= PHY_100BT_FEATURES | PHY_DEFAULT_FEATURES |
+				SUPPORTED_100baseT_Full | SUPPORTED_MII,
+	.probe		= ncsi_probe,
+	.startup	= ncsi_startup,
+	.shutdown	= ncsi_shutdown,
+};
+
+int phy_ncsi_init(void)
+{
+	phy_register(&ncsi_driver);
+	return 0;
+}