wifi: brcmfmac: add support for vendor-specific firmware api

The driver is being used by multiple vendors who develop the firmware
api independently. So far the firmware api as used by the driver has
not diverged (yet). This change adds framework for supporting multiple
firmware apis. The vendor-specific support code has to provide a number
of callback operations. Right now it is only attach and detach callbacks
so no real functionality as the api is still common. This code only
adds WCC variant anyway, which is selected for all devices right now.
The vendor-specific part will be built in a separate module when the
driver is configured to be built as a module through Kconfig, ie. when
CONFIG_BRCMFMAC=m.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221129135446.151065-4-arend.vanspriel@broadcom.com

drivers/net/wireless/broadcom/brcm80211/brcmfmac/Makefile

@@ -20,6 +20,7 @@ brcmfmac-objs += \
 		common.o \
 		core.o \
 		firmware.o \
+		fwvid.o \
 		feature.o \
 		btcoex.o \
 		vendor.o \
@@ -47,3 +48,9 @@ brcmfmac-$(CONFIG_OF) += \
 		of.o
 brcmfmac-$(CONFIG_DMI) += \
 		dmi.o
+
+ifeq ($(CONFIG_BRCMFMAC),m)
+obj-m += wcc/
+else
+brcmfmac-$(CONFIG_BRCMFMAC) += wcc/core.o
+endif

drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h

@@ -155,7 +155,9 @@ struct brcmf_bus_stats {
  * @fwvid: firmware vendor-support identifier of the device.
  * @always_use_fws_queue: bus wants use queue also when fwsignal is inactive.
  * @wowl_supported: is wowl supported by bus driver.
+ * @ops: callbacks for this bus instance.
  * @msgbuf: msgbuf protocol parameters provided by bus layer.
+ * @list: member used to add this bus instance to linked list.
  */
 struct brcmf_bus {
 	union {
@@ -177,6 +179,8 @@ struct brcmf_bus {
 
 	const struct brcmf_bus_ops *ops;
 	struct brcmf_bus_msgbuf *msgbuf;
+
+	struct list_head list;
 };
 
 /*

drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c

@@ -18,6 +18,7 @@
 
 #include "core.h"
 #include "bus.h"
+#include "fwvid.h"
 #include "debug.h"
 #include "fwil_types.h"
 #include "p2p.h"
@@ -1332,6 +1333,12 @@ int brcmf_attach(struct device *dev)
 	/* Link to bus module */
 	drvr->hdrlen = 0;
 
+	ret = brcmf_fwvid_attach(drvr);
+	if (ret != 0) {
+		bphy_err(drvr, "brcmf_fwvid_attach failed\n");
+		goto fail;
+	}
+
 	/* Attach and link in the protocol */
 	ret = brcmf_proto_attach(drvr);
 	if (ret != 0) {
@@ -1443,6 +1450,8 @@ void brcmf_detach(struct device *dev)
 		brcmf_cfg80211_detach(drvr->config);
 		drvr->config = NULL;
 	}
+
+	brcmf_fwvid_detach(drvr);
 }
 
 void brcmf_free(struct device *dev)

drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h

@@ -137,6 +137,8 @@ struct brcmf_pub {
 
 	u8 clmver[BRCMF_DCMD_SMLEN];
 	u8 sta_mac_idx;
+	const struct brcmf_fwvid_ops *vops;
+	void *vdata;
 };
 
 /* forward declarations */

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwvid.c

@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2022 Broadcom Corporation
+ */
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/printk.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+
+#include "core.h"
+#include "bus.h"
+#include "debug.h"
+#include "fwvid.h"
+
+#include "wcc/vops.h"
+
+struct brcmf_fwvid_entry {
+	const char *name;
+	const struct brcmf_fwvid_ops *vops;
+	struct list_head drvr_list;
+#if IS_MODULE(CONFIG_BRCMFMAC)
+	struct module *vmod;
+	struct completion reg_done;
+#endif
+};
+
+static DEFINE_MUTEX(fwvid_list_lock);
+
+#if IS_MODULE(CONFIG_BRCMFMAC)
+#define FWVID_ENTRY_INIT(_vid, _name) \
+	[BRCMF_FWVENDOR_ ## _vid] = { \
+		.name = #_name, \
+		.reg_done = COMPLETION_INITIALIZER(fwvid_list[BRCMF_FWVENDOR_ ## _vid].reg_done), \
+		.drvr_list = LIST_HEAD_INIT(fwvid_list[BRCMF_FWVENDOR_ ## _vid].drvr_list), \
+	}
+#else
+#define FWVID_ENTRY_INIT(_vid, _name) \
+	[BRCMF_FWVENDOR_ ## _vid] = { \
+		.name = #_name, \
+		.drvr_list = LIST_HEAD_INIT(fwvid_list[BRCMF_FWVENDOR_ ## _vid].drvr_list), \
+		.vops = _vid ## _VOPS \
+	}
+#endif /* IS_MODULE(CONFIG_BRCMFMAC) */
+
+static struct brcmf_fwvid_entry fwvid_list[BRCMF_FWVENDOR_NUM] = {
+	FWVID_ENTRY_INIT(WCC, wcc),
+};
+
+#if IS_MODULE(CONFIG_BRCMFMAC)
+static int brcmf_fwvid_request_module(enum brcmf_fwvendor fwvid)
+{
+	int ret;
+
+	if (!fwvid_list[fwvid].vmod) {
+		struct completion *reg_done = &fwvid_list[fwvid].reg_done;
+
+		mutex_unlock(&fwvid_list_lock);
+
+		ret = request_module("brcmfmac-%s", fwvid_list[fwvid].name);
+		if (ret)
+			goto fail;
+
+		ret = wait_for_completion_interruptible(reg_done);
+		if (ret)
+			goto fail;
+
+		mutex_lock(&fwvid_list_lock);
+	}
+	return 0;
+
+fail:
+	brcmf_err("mod=%s: failed %d\n", fwvid_list[fwvid].name, ret);
+	return ret;
+}
+
+int brcmf_fwvid_register_vendor(enum brcmf_fwvendor fwvid, struct module *vmod,
+				const struct brcmf_fwvid_ops *vops)
+{
+	if (fwvid >= BRCMF_FWVENDOR_NUM)
+		return -ERANGE;
+
+	if (WARN_ON(!vmod) || WARN_ON(!vops) ||
+	    WARN_ON(!vops->attach) || WARN_ON(!vops->detach))
+		return -EINVAL;
+
+	if (WARN_ON(fwvid_list[fwvid].vmod))
+		return -EEXIST;
+
+	brcmf_dbg(TRACE, "mod=%s: enter\n", fwvid_list[fwvid].name);
+
+	mutex_lock(&fwvid_list_lock);
+
+	fwvid_list[fwvid].vmod = vmod;
+	fwvid_list[fwvid].vops = vops;
+
+	mutex_unlock(&fwvid_list_lock);
+
+	complete_all(&fwvid_list[fwvid].reg_done);
+
+	return 0;
+}
+EXPORT_SYMBOL(brcmf_fwvid_register_vendor);
+
+int brcmf_fwvid_unregister_vendor(enum brcmf_fwvendor fwvid, struct module *mod)
+{
+	struct brcmf_bus *bus, *tmp;
+
+	if (fwvid >= BRCMF_FWVENDOR_NUM)
+		return -ERANGE;
+
+	if (WARN_ON(fwvid_list[fwvid].vmod != mod))
+		return -ENOENT;
+
+	mutex_lock(&fwvid_list_lock);
+
+	list_for_each_entry_safe(bus, tmp, &fwvid_list[fwvid].drvr_list, list) {
+		mutex_unlock(&fwvid_list_lock);
+
+		brcmf_dbg(INFO, "mod=%s: removing %s\n", fwvid_list[fwvid].name,
+			  dev_name(bus->dev));
+		brcmf_bus_remove(bus);
+
+		mutex_lock(&fwvid_list_lock);
+	}
+
+	fwvid_list[fwvid].vmod = NULL;
+	fwvid_list[fwvid].vops = NULL;
+	reinit_completion(&fwvid_list[fwvid].reg_done);
+
+	brcmf_dbg(TRACE, "mod=%s: exit\n", fwvid_list[fwvid].name);
+	mutex_unlock(&fwvid_list_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(brcmf_fwvid_unregister_vendor);
+#else
+static inline int brcmf_fwvid_request_module(enum brcmf_fwvendor fwvid)
+{
+	return 0;
+}
+#endif
+
+int brcmf_fwvid_attach_ops(struct brcmf_pub *drvr)
+{
+	enum brcmf_fwvendor fwvid = drvr->bus_if->fwvid;
+	int ret;
+
+	if (fwvid >= ARRAY_SIZE(fwvid_list))
+		return -ERANGE;
+
+	brcmf_dbg(TRACE, "mod=%s: enter: dev %s\n", fwvid_list[fwvid].name,
+		  dev_name(drvr->bus_if->dev));
+
+	mutex_lock(&fwvid_list_lock);
+
+	ret = brcmf_fwvid_request_module(fwvid);
+	if (ret)
+		return ret;
+
+	drvr->vops = fwvid_list[fwvid].vops;
+	list_add(&drvr->bus_if->list, &fwvid_list[fwvid].drvr_list);
+
+	mutex_unlock(&fwvid_list_lock);
+
+	return ret;
+}
+
+void brcmf_fwvid_detach_ops(struct brcmf_pub *drvr)
+{
+	enum brcmf_fwvendor fwvid = drvr->bus_if->fwvid;
+
+	if (fwvid >= ARRAY_SIZE(fwvid_list))
+		return;
+
+	brcmf_dbg(TRACE, "mod=%s: enter: dev %s\n", fwvid_list[fwvid].name,
+		  dev_name(drvr->bus_if->dev));
+
+	mutex_lock(&fwvid_list_lock);
+
+	drvr->vops = NULL;
+	list_del(&drvr->bus_if->list);
+
+	mutex_unlock(&fwvid_list_lock);
+}

drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwvid.h

@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Copyright (c) 2022 Broadcom Corporation
+ */
+#ifndef FWVID_H_
+#define FWVID_H_
+
+#include "firmware.h"
+
+struct brcmf_pub;
+
+struct brcmf_fwvid_ops {
+	int (*attach)(struct brcmf_pub *drvr);
+	void (*detach)(struct brcmf_pub *drvr);
+};
+
+/* exported functions */
+int brcmf_fwvid_register_vendor(enum brcmf_fwvendor fwvid, struct module *mod,
+				const struct brcmf_fwvid_ops *ops);
+int brcmf_fwvid_unregister_vendor(enum brcmf_fwvendor fwvid, struct module *mod);
+
+/* core driver functions */
+int brcmf_fwvid_attach_ops(struct brcmf_pub *drvr);
+void brcmf_fwvid_detach_ops(struct brcmf_pub *drvr);
+
+static inline int brcmf_fwvid_attach(struct brcmf_pub *drvr)
+{
+	int ret;
+
+	ret = brcmf_fwvid_attach_ops(drvr);
+	if (ret)
+		return ret;
+
+	return drvr->vops->attach(drvr);
+}
+
+static inline void brcmf_fwvid_detach(struct brcmf_pub *drvr)
+{
+	if (!drvr->vops)
+		return;
+
+	drvr->vops->detach(drvr);
+	brcmf_fwvid_detach_ops(drvr);
+}
+
+#endif /* FWVID_H_ */

drivers/net/wireless/broadcom/brcm80211/brcmfmac/wcc/Makefile

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: ISC
+#
+# Copyright (c) 2022 Broadcom Corporation
+
+ccflags-y += \
+	-I $(srctree)/$(src) \
+	-I $(srctree)/$(src)/.. \
+	-I $(srctree)/$(src)/../../include
+
+obj-m += brcmfmac-wcc.o
+brcmfmac-wcc-objs += \
+		core.o module.o

drivers/net/wireless/broadcom/brcm80211/brcmfmac/wcc/core.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2022 Broadcom Corporation
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <core.h>
+#include <bus.h>
+#include <fwvid.h>
+
+#include "vops.h"
+
+static int brcmf_wcc_attach(struct brcmf_pub *drvr)
+{
+	pr_err("%s: executing\n", __func__);
+	return 0;
+}
+
+static void brcmf_wcc_detach(struct brcmf_pub *drvr)
+{
+	pr_err("%s: executing\n", __func__);
+}
+
+const struct brcmf_fwvid_ops brcmf_wcc_ops = {
+	.attach = brcmf_wcc_attach,
+	.detach = brcmf_wcc_detach,
+};

drivers/net/wireless/broadcom/brcm80211/brcmfmac/wcc/module.c

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2022 Broadcom Corporation
+ */
+#include <linux/module.h>
+#include <bus.h>
+#include <core.h>
+#include <fwvid.h>
+
+#include "vops.h"
+
+static int __init brcmf_wcc_init(void)
+{
+	return brcmf_fwvid_register_vendor(BRCMF_FWVENDOR_WCC, THIS_MODULE,
+					   &brcmf_wcc_ops);
+}
+
+static void __exit brcmf_wcc_exit(void)
+{
+	brcmf_fwvid_unregister_vendor(BRCMF_FWVENDOR_WCC, THIS_MODULE);
+}
+
+MODULE_LICENSE("Dual BSD/GPL");
+
+module_init(brcmf_wcc_init);
+module_exit(brcmf_wcc_exit);

drivers/net/wireless/broadcom/brcm80211/brcmfmac/wcc/vops.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: ISC */
+/*
+ * Copyright (c) 2022 Broadcom Corporation
+ */
+#ifndef _BRCMFMAC_WCC_VOPS_H
+#define _BRCMFMAC_WCC_VOPS_H
+
+extern const struct brcmf_fwvid_ops brcmf_wcc_ops;
+#define WCC_VOPS	(&brcmf_wcc_ops)
+
+#endif /* _BRCMFMAC_WCC_VOPS_H */