sff: Add SFP driver (fdt-based draft)

This basic version of the driver obtains properties of the "sff,sfp"
compatible devices and implements a simple interface to provide an I2C
bus device for the rest of the drivers (e.g. to implement SIOCGI2C).

Both of the interface and driver are subjects for a further
generalization to be used in case of non-FDT and non-arm64 platforms.

Reviewed by:		bz, manu
Approved by:		bz (mentor)
MFC after:		3 weeks
Differential Revision:	https://reviews.freebsd.org/D41440

sys/arm64/conf/std.nxp

@@ -25,6 +25,9 @@ device		sdhci
 device		dpaa2			# Data Path Acceleration Architecture (2nd Gen)
 device		enetc			# QorIQ LS1028A NIC
 
+# SFF/SFP
+device		sff			# Small Form Factor Transceivers
+
 options 	FDT
 device		acpi
 

sys/conf/files

@@ -3044,6 +3044,8 @@ dev/sdhci/sdhci_pci.c		optional sdhci pci
 dev/sdio/sdio_if.m		optional mmccam
 dev/sdio/sdio_subr.c		optional mmccam
 dev/sdio/sdiob.c		optional mmccam
+dev/sff/sff_if.m		optional sff
+dev/sff/sfp_fdt.c		optional sff fdt
 dev/sge/if_sge.c		optional sge pci
 dev/siis/siis.c			optional siis pci
 dev/sis/if_sis.c		optional sis pci

sys/dev/sff/sff_if.m

@@ -0,0 +1,35 @@
+#-
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright © 2023 Dmitry Salychev
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+
+#include <machine/bus.h>
+
+INTERFACE sff;
+
+METHOD int get_i2c_bus {
+	device_t		 dev;
+	device_t		*i2c_bus;
+};

sys/dev/sff/sfp_fdt.c

@@ -0,0 +1,155 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright © 2023 Dmitry Salychev
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Small Form Factor (SFF) Committee Pluggable (SFP) Transceiver (FDT-based).
+ */
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/bus.h>
+#include <sys/module.h>
+
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/fdt/simplebus.h>
+
+#include "sff_if.h"
+
+struct sfp_fdt_softc {
+	phandle_t	ofw_node;
+	phandle_t	i2c_bus;
+
+	phandle_t	mod_def;
+	phandle_t	los;
+	phandle_t	tx_fault;
+	phandle_t	tx_disable;
+	phandle_t	rx_rate;
+	phandle_t	tx_rate;
+	uint32_t	max_power; /* in mW */
+};
+
+static int
+sfp_fdt_probe(device_t dev)
+{
+	phandle_t node;
+	ssize_t s;
+
+	node = ofw_bus_get_node(dev);
+	if (!ofw_bus_node_is_compatible(node, "sff,sfp"))
+		return (ENXIO);
+
+	s = device_get_property(dev, "i2c-bus", &node, sizeof(node),
+	    DEVICE_PROP_HANDLE);
+	if (s == -1) {
+		device_printf(dev, "%s: '%s' has no 'i2c-bus' property, s %zd\n",
+		    __func__, ofw_bus_get_name(dev), s);
+		return (ENXIO);
+	}
+
+	device_set_desc(dev, "Small Form-factor Pluggable Transceiver");
+	return (BUS_PROBE_DEFAULT);
+}
+
+static int
+sfp_fdt_attach(device_t dev)
+{
+	struct sfp_fdt_softc *sc;
+	ssize_t s;
+	int error;
+
+	sc = device_get_softc(dev);
+	sc->ofw_node = ofw_bus_get_node(dev);
+
+	s = device_get_property(dev, "i2c-bus", &sc->i2c_bus,
+	    sizeof(sc->i2c_bus), DEVICE_PROP_HANDLE);
+	if (s == -1) {
+		device_printf(dev, "%s: cannot find 'i2c-bus' property: %zd\n",
+		    __func__, s);
+		return (ENXIO);
+	}
+
+	/* Optional properties */
+	(void)device_get_property(dev, "mod-def0-gpios", &sc->mod_def,
+	    sizeof(sc->mod_def), DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "los-gpios", &sc->los, sizeof(sc->los),
+	    DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "tx-fault-gpios", &sc->tx_fault,
+	    sizeof(sc->tx_fault), DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "tx-disable-gpios", &sc->tx_disable,
+	    sizeof(sc->tx_disable), DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "rate-select0-gpios", &sc->rx_rate,
+	    sizeof(sc->rx_rate), DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "rate-select1-gpios", &sc->tx_rate,
+	    sizeof(sc->tx_rate), DEVICE_PROP_HANDLE);
+	(void)device_get_property(dev, "maximum-power-milliwatt", &sc->max_power,
+	    sizeof(sc->max_power), DEVICE_PROP_UINT32);
+
+	error = OF_device_register_xref(OF_xref_from_node(sc->ofw_node), dev);
+	if (error != 0)
+		device_printf(dev, "%s: failed to register xref %#x\n",
+		    __func__, OF_xref_from_node(sc->ofw_node));
+
+	return (error);
+}
+
+static int
+sfp_fdt_get_i2c_bus(device_t dev, device_t *i2c_bus)
+{
+	struct sfp_fdt_softc *sc;
+	device_t xdev;
+
+	KASSERT(i2c_bus != NULL, ("%s: i2c_bus is NULL", __func__));
+
+	sc = device_get_softc(dev);
+	xdev = OF_device_from_xref(OF_xref_from_node(sc->i2c_bus));
+	if (xdev == NULL)
+		return (ENXIO);
+
+	*i2c_bus = xdev;
+	return (0);
+}
+
+static device_method_t sfp_fdt_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		sfp_fdt_probe),
+	DEVMETHOD(device_attach,	sfp_fdt_attach),
+	DEVMETHOD(device_detach,	bus_generic_detach),
+
+	/* SFF */
+	DEVMETHOD(sff_get_i2c_bus,	sfp_fdt_get_i2c_bus),
+
+	DEVMETHOD_END
+};
+
+DEFINE_CLASS_0(sfp_fdt, sfp_fdt_driver, sfp_fdt_methods,
+    sizeof(struct sfp_fdt_softc));
+
+EARLY_DRIVER_MODULE(sfp_fdt, simplebus, sfp_fdt_driver, 0, 0,
+    BUS_PASS_SUPPORTDEV);
+EARLY_DRIVER_MODULE(sfp_fdt, ofwbus, sfp_fdt_driver, 0, 0,
+    BUS_PASS_SUPPORTDEV);

sys/modules/Makefile

@@ -355,6 +355,7 @@ SUBDIR=	\
 	${_sdhci_fdt} \
 	sdhci_pci \
 	sdio \
+	${_sff} \
 	sem \
 	send \
 	${_sfxge} \
@@ -678,6 +679,7 @@ _cxgb=		cxgb
 .if ${MACHINE_CPUARCH} == "aarch64"
 _armv8crypto=	armv8crypto
 _dpaa2=		dpaa2
+_sff=		sff
 _em=		em
 _hyperv=  hyperv
 

sys/modules/sff/Makefile

@@ -0,0 +1,13 @@
+.PATH:	${SRCTOP}/sys/dev/sff
+
+KMOD=	sff
+
+SRCS+=	sff_if.c sff_if.h
+SRCS+=	bus_if.h device_if.h
+
+.if !empty(OPT_FDT)
+SRCS+=	sfp_fdt.c \
+	ofw_bus_if.h
+.endif
+
+.include <bsd.kmod.mk>