[PATCH wireless-next v2 08/34] wifi: inffmac: add icdc.c/h

[Gokul Sivakumar <gokulkumar.sivakumar@infineon.com>]

Driver implementation of the ICDC protocol used for the Control and Data
communication with Infineon's Chipsets that have the Connectivity processor
(CP) architecture like the CYW5591x sub-family of chipsets, using SDIO.

Signed-off-by: Gokul Sivakumar <gokulkumar.sivakumar@infineon.com>
---
 drivers/net/wireless/infineon/inffmac/icdc.c | 450 +++++++++++++++++++
 drivers/net/wireless/infineon/inffmac/icdc.h |  34 ++
 2 files changed, 484 insertions(+)
 create mode 100644 drivers/net/wireless/infineon/inffmac/icdc.c
 create mode 100644 drivers/net/wireless/infineon/inffmac/icdc.h

diff --git a/drivers/net/wireless/infineon/inffmac/icdc.c b/drivers/net/wireless/infineon/inffmac/icdc.c
new file mode 100644
index 000000000000..86da37f756ca
--- /dev/null
+++ b/drivers/net/wireless/infineon/inffmac/icdc.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2010 Broadcom Corporation
+ *
+ * Copyright (c) 2025-2026, Infineon Technologies AG, or an affiliate of Infineon Technologies AG.
+ * All rights reserved.
+ */
+
+/*******************************************************************************
+ * Communicates with the dongle by using dcmd (CP and FW) codes.
+ * For certain dcmd codes, the dongle interprets string data from the host.
+ ******************************************************************************/
+
+#include <linux/types.h>
+#include <linux/netdevice.h>
+
+#include "main.h"
+#include "net.h"
+#include "utils.h"
+#include "fwsignal.h"
+#include "debug.h"
+#include "bus_proto.h"
+#include "icdc.h"
+
+struct inff_proto_icdc_dcmd {
+	__le32 cmd;	/* dongle command value */
+	__le32 len;	/* lower 16: output buflen;
+			 * upper 16: input buflen (excludes header)
+			 */
+	__le32 flags;	/* flag defns given below */
+	__le32 status;	/* status code returned from the device */
+	unsigned char ioc_key[ICDC_GCM_KEY_SIZE_BYTES];	/* key used for ioc enc */
+	unsigned char ioc_iv[ICDC_GCM_IV_SIZE];	/* enc field */
+};
+
+/* ICDC flag definitions */
+#define ICDC_DCMD_ERROR		0x01		/* 1=cmd failed */
+#define ICDC_DCMD_SET		0x02		/* 0=get, 1=set cmd */
+#define ICDC_DCMD_IF_MASK	0xF000		/* I/F index */
+#define ICDC_DCMD_IF_SHIFT	12
+#define ICDC_DCMD_ID_MASK	0xFFFF0000	/* id an cmd pairing */
+#define ICDC_DCMD_ID_SHIFT	16		/* ID Mask shift bits */
+#define ICDC_DCMD_ID(flags)	\
+	(((flags) & ICDC_DCMD_ID_MASK) >> ICDC_DCMD_ID_SHIFT)
+
+/*
+ * ICDC header - Infineon specific extension of CDC.
+ * Used on data packets to convey priority.
+ */
+#define	ICDC_HEADER_LEN		4
+#define ICDC_PROTO_VER		2	/* Protocol version */
+#define ICDC_FLAG_VER_MASK	0xf0	/* Protocol version mask */
+#define ICDC_FLAG_VER_SHIFT	4	/* Protocol version shift */
+#define ICDC_FLAG_SUM_GOOD	0x04	/* Good RX checksums */
+#define ICDC_FLAG_SUM_NEEDED	0x08	/* Dongle needs to do TX checksums */
+#define ICDC_PRIORITY_MASK	0x7
+#define ICDC_FLAG2_IF_MASK	0x0f	/* packet rx interface in APSTA */
+#define ICDC_FLAG2_IF_SHIFT	0
+
+#define ICDC_GET_IF_IDX(hdr) \
+	((int)((((hdr)->flags2) & ICDC_FLAG2_IF_MASK) >> ICDC_FLAG2_IF_SHIFT))
+#define ICDC_SET_IF_IDX(hdr, idx) {\
+	typeof(hdr) _hdr = (hdr); \
+	((_hdr)->flags2 = (((_hdr)->flags2 & ~ICDC_FLAG2_IF_MASK) | \
+	((idx) << ICDC_FLAG2_IF_SHIFT))); \
+	}
+
+/**
+ * struct inff_proto_icdc_header - ICDC header format
+ *
+ * @flags: flags contain protocol and checksum info.
+ * @priority: 802.1d priority.
+ * @flags2: additional flags containing dongle interface index.
+ * @data_offset: start of packet data. header is following by firmware signals.
+ */
+struct inff_proto_icdc_header {
+	u8 flags;
+	u8 priority;
+	u8 flags2;
+	u8 data_offset;
+	unsigned char data_key[ICDC_GCM_KEY_SIZE_BYTES];	/* key used for ioc enc */
+	unsigned char data_iv[ICDC_GCM_IV_SIZE];	/* enc field */
+};
+
+/*
+ * maximum length of firmware signal data between
+ * the ICDC header and packet data in the tx path.
+ */
+#define INFF_PROT_FW_SIGNAL_MAX_TXBYTES	12
+
+#define RETRIES 2 /* # of retries to retrieve matching dcmd response */
+#define BUS_HEADER_LEN	(16 + 64)	/* Must be at least SDPCM_RESERVE
+					 * (amount of header tha might be added)
+					 * plus any space that might be needed
+					 * for bus alignment padding.
+					 */
+#define ROUND_UP_MARGIN 2048
+
+struct inff_icdc {
+	u16 reqid;
+	u8 bus_header[BUS_HEADER_LEN];
+	struct inff_proto_icdc_dcmd msg;
+	unsigned char buf[INFF_DCMD_MAXLEN];
+};
+
+static int
+inff_proto_icdc_msg(struct inff_pub *drvr, int ifidx, uint cmd, void *buf,
+		    uint len, bool set)
+{
+	struct inff_icdc *icdc = (struct inff_icdc *)drvr->proto->pd;
+	struct inff_proto_icdc_dcmd *msg = &icdc->msg;
+	u32 flags;
+
+	memset(msg, 0, sizeof(struct inff_proto_icdc_dcmd));
+
+	msg->cmd = cpu_to_le32(cmd);
+	msg->len = cpu_to_le32(len);
+	flags = (++icdc->reqid << ICDC_DCMD_ID_SHIFT);
+
+	flags = (ICDC_PROTO_VER << ICDC_FLAG_VER_SHIFT);
+	flags |= (++icdc->reqid << ICDC_DCMD_ID_SHIFT);
+
+	if (set)
+		flags |= ICDC_DCMD_SET;
+	flags = (flags & ~ICDC_DCMD_IF_MASK) |
+		(ifidx << ICDC_DCMD_IF_SHIFT);
+	msg->flags = cpu_to_le32(flags);
+
+	if (buf)
+		memcpy(icdc->buf, buf, len);
+
+	len += sizeof(*msg);
+	if (len > INFF_TX_IOCTL_MAX_MSG_SIZE)
+		len = INFF_TX_IOCTL_MAX_MSG_SIZE;
+
+	/* Send request */
+	return inff_bus_txctl(drvr->bus_if, (unsigned char *)&icdc->msg, len);
+}
+
+static int
+inff_proto_icdc_cmplt(struct inff_pub *drvr, u32 id, u32 len)
+{
+	int ret;
+	struct inff_icdc *icdc = (struct inff_icdc *)drvr->proto->pd;
+
+	len += sizeof(struct inff_proto_icdc_dcmd);
+	do {
+		ret = inff_bus_rxctl(drvr->bus_if, (unsigned char *)&icdc->msg,
+				     len);
+		if (ret < 0)
+			break;
+	} while (ICDC_DCMD_ID(le32_to_cpu(icdc->msg.flags)) != id);
+
+	return ret;
+}
+
+static int
+inff_proto_icdc_query_dcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			   void *buf, uint len, int *err)
+{
+	struct inff_icdc *icdc = (struct inff_icdc *)drvr->proto->pd;
+	struct inff_proto_icdc_dcmd *msg = &icdc->msg;
+	void *info;
+	int ret = 0, retries = 0;
+	u32 id, flags;
+
+	*err = 0;
+	ret = inff_proto_icdc_msg(drvr, ifidx, cmd, buf, len, false);
+	if (ret < 0) {
+		iphy_err(drvr, "inff_proto_icdc_msg failed w/status %d\n",
+			 ret);
+		goto done;
+	}
+
+retry:
+	/* wait for interrupt and get first fragment */
+	ret = inff_proto_icdc_cmplt(drvr, icdc->reqid, len);
+	if (ret < 0)
+		goto done;
+
+	flags = le32_to_cpu(msg->flags);
+	id = (flags & ICDC_DCMD_ID_MASK) >> ICDC_DCMD_ID_SHIFT;
+
+	if (id < icdc->reqid && (++retries < RETRIES))
+		goto retry;
+	if (id != icdc->reqid) {
+		iphy_err(drvr, "%s: unexpected request id %d (expected %d)\n",
+			 inff_ifname(inff_get_ifp(drvr, ifidx)), id,
+			 icdc->reqid);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/* Check info buffer */
+	info = (void *)&icdc->buf[0];
+
+	/* Copy info buffer */
+	if (buf) {
+		if (ret < (int)len)
+			len = ret;
+		memcpy(buf, info, len);
+	}
+
+	ret = 0;
+
+	/* Check the ERROR flag */
+	if (flags & ICDC_DCMD_ERROR)
+		*err = le32_to_cpu(msg->status);
+done:
+	return ret;
+}
+
+static int
+inff_proto_icdc_query_cpcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			    void *buf, uint len, int *cperr)
+{
+	inff_dbg(ICDC, "cmd %d len %d\n", cmd, len);
+
+	cmd = (CMD_TYPE_CP << CMD_TYPE_SHIFT) | cmd;
+
+	return inff_proto_icdc_query_dcmd(drvr, ifidx, cmd,
+					  buf, len, cperr);
+}
+
+static int
+inff_proto_icdc_query_fwcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			    void *buf, uint len, int *fwerr)
+{
+	inff_dbg(ICDC, "cmd %d len %d\n", cmd, len);
+
+	cmd = (CMD_TYPE_WL << CMD_TYPE_SHIFT) | cmd;
+
+	return inff_proto_icdc_query_dcmd(drvr, ifidx, cmd,
+					  buf, len, fwerr);
+}
+
+static int
+inff_proto_icdc_set_dcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			 void *buf, uint len, int *err)
+{
+	struct inff_icdc *icdc = (struct inff_icdc *)drvr->proto->pd;
+	struct inff_proto_icdc_dcmd *msg = &icdc->msg;
+	int ret;
+	u32 flags, id;
+
+	inff_dbg(ICDC, "cmd %d len %d\n", cmd, len);
+
+	*err = 0;
+	ret = inff_proto_icdc_msg(drvr, ifidx, cmd, buf, len, true);
+	if (ret < 0)
+		goto done;
+
+	ret = inff_proto_icdc_cmplt(drvr, icdc->reqid, len);
+	if (ret < 0)
+		goto done;
+
+	flags = le32_to_cpu(msg->flags);
+	id = (flags & ICDC_DCMD_ID_MASK) >> ICDC_DCMD_ID_SHIFT;
+
+	if (id != icdc->reqid) {
+		iphy_err(drvr, "%s: unexpected request id %d (expected %d)\n",
+			 inff_ifname(inff_get_ifp(drvr, ifidx)), id,
+			 icdc->reqid);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	ret = 0;
+
+	/* Check the ERROR flag */
+	if (flags & ICDC_DCMD_ERROR)
+		*err = le32_to_cpu(msg->status);
+
+done:
+	return ret;
+}
+
+static int
+inff_proto_icdc_set_cpcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			  void *buf, uint len, int *cperr)
+{
+	inff_dbg(ICDC, "cmd %d len %d\n", cmd, len);
+
+	cmd = (CMD_TYPE_CP << CMD_TYPE_SHIFT) | cmd;
+
+	return inff_proto_icdc_set_dcmd(drvr, ifidx, cmd,
+					buf, len, cperr);
+}
+
+static int
+inff_proto_icdc_set_fwcmd(struct inff_pub *drvr, int ifidx, uint cmd,
+			  void *buf, uint len, int *fwerr)
+{
+	inff_dbg(ICDC, "cmd %d len %d\n", cmd, len);
+
+	cmd = (CMD_TYPE_WL << CMD_TYPE_SHIFT) | cmd;
+
+	return inff_proto_icdc_set_dcmd(drvr, ifidx, cmd,
+					buf, len, fwerr);
+}
+
+static void
+inff_proto_icdc_hdrpush(struct inff_pub *drvr, int ifidx, u8 offset,
+			struct sk_buff *pktbuf)
+{
+	struct inff_proto_icdc_header *h;
+
+	/* Push BDC header used to convey priority for buses that don't */
+	skb_push(pktbuf, ICDC_HEADER_LEN);
+
+	h = (struct inff_proto_icdc_header *)(pktbuf->data);
+
+	h->flags = (ICDC_PROTO_VER << ICDC_FLAG_VER_SHIFT);
+	if (pktbuf->ip_summed == CHECKSUM_PARTIAL)
+		h->flags |= ICDC_FLAG_SUM_NEEDED;
+
+	h->priority = (pktbuf->priority & ICDC_PRIORITY_MASK);
+	h->flags2 = 0;
+	h->data_offset = offset;
+	ICDC_SET_IF_IDX(h, ifidx);
+}
+
+static int
+inff_proto_icdc_hdrpull(struct inff_pub *drvr, bool do_fws,
+			struct sk_buff *pktbuf, struct inff_if **ifp)
+{
+	struct inff_proto_icdc_header *h;
+	struct inff_if *tmp_if;
+
+	/* Pop ICDC header used to convey priority for buses that don't */
+	if (pktbuf->len <= ICDC_HEADER_LEN) {
+		inff_dbg(INFO, "rx data too short (%d <= %d)\n",
+			 pktbuf->len, ICDC_HEADER_LEN);
+		return -EBADE;
+	}
+
+	h = (struct inff_proto_icdc_header *)(pktbuf->data);
+
+	tmp_if = inff_get_ifp(drvr, ICDC_GET_IF_IDX(h));
+	if (!tmp_if) {
+		inff_dbg(INFO, "no matching ifp found for ifidx: %d\n",
+			 ICDC_GET_IF_IDX(h));
+		return -EBADE;
+	}
+	if (((h->flags & ICDC_FLAG_VER_MASK) >> ICDC_FLAG_VER_SHIFT) !=
+	    ICDC_PROTO_VER) {
+		iphy_err(drvr, "%s: non-ICDC packet received, flags 0x%x\n",
+			 inff_ifname(tmp_if), h->flags);
+		return -EBADE;
+	}
+
+	if (h->flags & ICDC_FLAG_SUM_GOOD) {
+		inff_dbg(ICDC, "%s: BDC rcv, good checksum, flags 0x%x\n",
+			 inff_ifname(tmp_if), h->flags);
+		pktbuf->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+
+	pktbuf->priority = h->priority & ICDC_PRIORITY_MASK;
+
+	skb_pull(pktbuf, ICDC_HEADER_LEN);
+	if (do_fws)
+		inff_fws_hdrpull(tmp_if, h->data_offset << 2, pktbuf);
+	else
+		skb_pull(pktbuf, h->data_offset << 2);
+
+	if (pktbuf->len == 0)
+		return -ENODATA;
+
+	if (ifp)
+		*ifp = tmp_if;
+	return 0;
+}
+
+static int
+inff_proto_icdc_tx_queue_data(struct inff_pub *drvr, int ifidx,
+			      struct sk_buff *skb)
+{
+	return inff_proto_txdata(drvr, ifidx, 0, skb);
+}
+
+static int
+inff_proto_icdc_txdata(struct inff_pub *drvr, int ifidx, u8 offset,
+		       struct sk_buff *pktbuf)
+{
+	inff_proto_icdc_hdrpush(drvr, ifidx, offset, pktbuf);
+	return inff_bus_txdata(drvr->bus_if, pktbuf);
+}
+
+static void
+inff_proto_icdc_configure_addr_mode(struct inff_pub *drvr, int ifidx,
+				    enum proto_addr_mode addr_mode)
+{
+}
+
+static void
+inff_proto_icdc_delete_peer(struct inff_pub *drvr, int ifidx,
+			    u8 peer[ETH_ALEN])
+{
+}
+
+static void
+inff_proto_icdc_debugfs_create(struct inff_pub *drvr)
+{
+}
+
+int
+inff_proto_icdc_attach(struct inff_pub *drvr)
+{
+	struct inff_icdc *icdc;
+
+	icdc = kzalloc(sizeof(*icdc), GFP_ATOMIC);
+	if (!icdc)
+		goto fail;
+
+	/* ensure that the msg buf directly follows the cdc msg struct */
+	if ((unsigned long)(&icdc->msg + 1) != (unsigned long)icdc->buf) {
+		iphy_err(drvr, "struct inff_proto_icdc is not correctly defined\n");
+		goto fail;
+	}
+
+	drvr->proto->query_cpcmd = inff_proto_icdc_query_cpcmd;
+	drvr->proto->set_cpcmd = inff_proto_icdc_set_cpcmd;
+	drvr->proto->query_fwcmd = inff_proto_icdc_query_fwcmd;
+	drvr->proto->set_fwcmd = inff_proto_icdc_set_fwcmd;
+	drvr->proto->hdrpull = inff_proto_icdc_hdrpull;
+	drvr->proto->tx_queue_data = inff_proto_icdc_tx_queue_data;
+	drvr->proto->txdata = inff_proto_icdc_txdata;
+	drvr->proto->configure_addr_mode = inff_proto_icdc_configure_addr_mode;
+	drvr->proto->delete_peer = inff_proto_icdc_delete_peer;
+	drvr->proto->debugfs_create = inff_proto_icdc_debugfs_create;
+	drvr->proto->pd = icdc;
+
+	drvr->hdrlen += ICDC_HEADER_LEN + INFF_PROT_FW_SIGNAL_MAX_TXBYTES;
+	drvr->bus_if->maxctl = INFF_DCMD_MAXLEN +
+			sizeof(struct inff_proto_icdc_dcmd) + ROUND_UP_MARGIN;
+	return 0;
+
+fail:
+	kfree(icdc);
+	return -ENOMEM;
+}
+
+void
+inff_proto_icdc_detach(struct inff_pub *drvr)
+{
+	struct inff_icdc *icdc = drvr->proto->pd;
+
+	drvr->proto->pd = NULL;
+	kfree(icdc);
+}
diff --git a/drivers/net/wireless/infineon/inffmac/icdc.h b/drivers/net/wireless/infineon/inffmac/icdc.h
new file mode 100644
index 000000000000..c1fb4c23a055
--- /dev/null
+++ b/drivers/net/wireless/infineon/inffmac/icdc.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Copyright (c) 2013 Broadcom Corporation
+ *
+ * Copyright (c) 2025-2026, Infineon Technologies AG, or an affiliate of Infineon Technologies AG.
+ * All rights reserved.
+ */
+
+#ifndef INFF_ICDC_H
+#define INFF_ICDC_H
+
+#define ICDC_PROTO_ENC             (0x01)
+#define ICDC_IOC_ENC_MASK          (0x200)
+#define ICDC_IOC_ENC_SHIFT         (0x09)
+
+#define ICDC_DAT_ENC_MASK          (0x20)
+#define ICDC_DAT_ENC_SHIFT         (0x05)
+
+#define ICDC_GCM_KEY_SIZE_BYTES    (16)
+#define ICDC_GCM_IV_SIZE           (12)
+
+#ifdef CONFIG_INFFMAC_PROTO_ICDC
+int inff_proto_icdc_attach(struct inff_pub *drvr);
+void inff_proto_icdc_detach(struct inff_pub *drvr);
+void inff_proto_icdc_txflowblock(struct device *dev, bool state);
+void inff_icdc_process_event(struct device *dev, struct sk_buff *skb);
+struct sk_buff *inff_icdc_rx(struct device *dev, struct sk_buff *skb,
+			     bool handle_event, bool inirq);
+#else
+static inline int inff_proto_icdc_attach(struct inff_pub *drvr) { return 0; }
+static inline void inff_proto_icdc_detach(struct inff_pub *drvr) {}
+#endif
+
+#endif /* INFF_ICDC_H */
-- 
2.25.1