svn commit: r346517 - in stable/11/sys: conf dev/spibus

[Ian Lepore]

Author: ian
Date: Mon Apr 22 03:52:11 2019
New Revision: 346517
URL: https://svnweb.freebsd.org/changeset/base/346517

Log:
  MFC r335506
  
  r335506:
  Incorporate bus and chip select numbers into spigen(4) cdev names.  Rather
  than assigning spigen device names in order of creation, this uses a device
  name that corresponds to the owning spibus and chip-select index.
  
  Example: /dev/spigen0.1 would be a child of spibus0, and use cs = 1
  
  The intent is for systems like Raspberry Pi to have a consistent way of
  using an SPI interface with a specific cs value from a user application.
  Otherwise, there is no consistent way of knowing which cs pin will be
  assigned to a particular spigen device. The alternative is to specify
  everything in "the right order" in an overlay file, which is less than
  ideal. Additionally, this duplicates (to some extent) the way Linux handles
  a similar situation with their 'spidev' device, so it would be somewhat
  familiar to those who also use Linux.
  
  A new kernel config option, SPIGEN_LEGACY_CDEVNAME, causes the driver to
  also create /dev/spigenN device name aliases, with N incrementing in the
  order of device instantiation.  This is provided to ease the transition
  for existing systems using the original naming convention (particularly
  when these changes are MFC'd to stable branches).
  
  Differential Revision:	https://reviews.freebsd.org/D15301

Modified:
  stable/11/sys/conf/NOTES
  stable/11/sys/conf/options
  stable/11/sys/dev/spibus/spibus.c
  stable/11/sys/dev/spibus/spigen.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/conf/NOTES
==============================================================================
--- stable/11/sys/conf/NOTES	Mon Apr 22 03:25:49 2019	(r346516)
+++ stable/11/sys/conf/NOTES	Mon Apr 22 03:52:11 2019	(r346517)
@@ -3074,4 +3074,7 @@ options 	EVDEV_DEBUG	# enable event debug msgs
 device		uinput		# install /dev/uinput cdev
 options 	UINPUT_DEBUG	# enable uinput debug msgs
 
+# Enable legacy /dev/spigenN name aliases for /dev/spigenX.Y devices.
+options 	SPIGEN_LEGACY_CDEVNAME # legacy device names for spigen
+
 device		xz		# xz_embedded LZMA de-compression library

Modified: stable/11/sys/conf/options
==============================================================================
--- stable/11/sys/conf/options	Mon Apr 22 03:25:49 2019	(r346516)
+++ stable/11/sys/conf/options	Mon Apr 22 03:52:11 2019	(r346517)
@@ -992,6 +992,9 @@ BHND_LOGLEVEL	opt_global.h
 # GPIO and child devices
 GPIO_SPI_DEBUG	opt_gpio.h
 
+# SPI devices
+SPIGEN_LEGACY_CDEVNAME	opt_spi.h
+
 # etherswitch(4) driver
 RTL8366_SOFT_RESET opt_etherswitch.h
 

Modified: stable/11/sys/dev/spibus/spibus.c
==============================================================================
--- stable/11/sys/dev/spibus/spibus.c	Mon Apr 22 03:25:49 2019	(r346516)
+++ stable/11/sys/dev/spibus/spibus.c	Mon Apr 22 03:52:11 2019	(r346517)
@@ -122,8 +122,10 @@ spibus_child_location_str(device_t bus, device_t child
     size_t buflen)
 {
 	struct spibus_ivar *devi = SPIBUS_IVAR(child);
+	int cs;
 
-	snprintf(buf, buflen, "cs=%d", devi->cs);
+	cs = devi->cs & ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
+	snprintf(buf, buflen, "bus=%d cs=%d", device_get_unit(bus), cs);
 	return (0);
 }
 

Modified: stable/11/sys/dev/spibus/spigen.c
==============================================================================
--- stable/11/sys/dev/spibus/spigen.c	Mon Apr 22 03:25:49 2019	(r346516)
+++ stable/11/sys/dev/spibus/spigen.c	Mon Apr 22 03:52:11 2019	(r346517)
@@ -26,6 +26,7 @@
 __FBSDID("$FreeBSD$");
 
 #include "opt_platform.h"
+#include "opt_spi.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -64,6 +65,9 @@ __FBSDID("$FreeBSD$");
 struct spigen_softc {
 	device_t sc_dev;
 	struct cdev *sc_cdev;
+#ifdef SPIGEN_LEGACY_CDEVNAME
+	struct cdev *sc_adev;           /* alias device */
+#endif
 	struct mtx sc_mtx;
 	uint32_t sc_command_length_max; /* cannot change while mmapped */
 	uint32_t sc_data_length_max;    /* cannot change while mmapped */
@@ -186,15 +190,46 @@ spigen_attach(device_t dev)
 {
 	struct spigen_softc *sc;
 	const int unit = device_get_unit(dev);
+	int cs, res;
+	struct make_dev_args mda;
 
+	spibus_get_cs(dev, &cs);
+	cs &= ~SPIBUS_CS_HIGH; /* trim 'cs high' bit */
+
 	sc = device_get_softc(dev);
 	sc->sc_dev = dev;
-	sc->sc_cdev = make_dev(&spigen_cdevsw, unit,
-	    UID_ROOT, GID_OPERATOR, 0660, "spigen%d", unit);
-	sc->sc_cdev->si_drv1 = dev;
 	sc->sc_command_length_max = PAGE_SIZE;
 	sc->sc_data_length_max = PAGE_SIZE;
+
 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
+
+	make_dev_args_init(&mda);
+	mda.mda_flags = MAKEDEV_WAITOK;
+	mda.mda_devsw = &spigen_cdevsw;
+	mda.mda_cr = NULL;
+	mda.mda_uid = UID_ROOT;
+	mda.mda_gid = GID_OPERATOR;
+	mda.mda_mode = 0660;
+	mda.mda_unit = unit;
+	mda.mda_si_drv1 = dev;
+
+	res = make_dev_s(&mda, &(sc->sc_cdev), "spigen%d.%d",
+	    device_get_unit(device_get_parent(dev)), cs);
+	if (res) {
+		return res;
+	}
+
+#ifdef SPIGEN_LEGACY_CDEVNAME
+	res = make_dev_alias_p(0, &sc->sc_adev, sc->sc_cdev, "spigen%d", unit);
+	if (res) {
+		if (sc->sc_cdev) {
+			destroy_dev(sc->sc_cdev);
+			sc->sc_cdev = NULL;
+		}
+		return res;
+	}
+#endif
+
 	spigen_sysctl_init(sc);
 
 	return (0);
@@ -429,8 +464,13 @@ spigen_detach(device_t dev)
 
 	mtx_destroy(&sc->sc_mtx);
 
-        if (sc->sc_cdev)
-                destroy_dev(sc->sc_cdev);
+#ifdef SPIGEN_LEGACY_CDEVNAME
+	if (sc->sc_adev)
+		destroy_dev(sc->sc_adev);
+#endif
+
+	if (sc->sc_cdev)
+		destroy_dev(sc->sc_cdev);
 	
 	return (0);
 }