/*- * Copyright (c) 1998, 2001 Nicolas Souchu * All rights reserved. * * 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. * * $FreeBSD: src/sys/dev/iicbus/iicbus.c,v 1.29 2009/02/10 22:50:23 imp Exp $ */ /* * Autoconfiguration and support routines for the Philips serial I2C bus */ #include #include #include #include #include #include #include #include #include "iicbus_if.h" /* DEVTOIICBUS removed: it referenced struct iicbus_device, which no * longer exists anywhere in the tree (dead macro since the ivar rework) */ devclass_t iicbus_devclass; /* See comments below for why auto-scanning is a bad idea. */ #define SCAN_IICBUS 0 /* * Device methods */ static int iicbus_probe(device_t); static int iicbus_attach(device_t); static int iicbus_detach(device_t); static device_t iicbus_add_child(device_t bus, device_t parent, int order, const char *name, int unit); static void iicbus_child_detached(device_t bus, device_t child); static int iicbus_read_ivar(device_t, device_t, int, uintptr_t *); static int iicbus_write_ivar(device_t, device_t, int, uintptr_t); static device_method_t iicbus_methods[] = { /* device interface */ DEVMETHOD(device_probe, iicbus_probe), DEVMETHOD(device_attach, iicbus_attach), DEVMETHOD(device_detach, iicbus_detach), /* bus interface */ DEVMETHOD(bus_add_child, iicbus_add_child), DEVMETHOD(bus_driver_added, bus_generic_driver_added), DEVMETHOD(bus_print_child, bus_generic_print_child), DEVMETHOD(bus_child_detached, iicbus_child_detached), DEVMETHOD(bus_read_ivar, iicbus_read_ivar), DEVMETHOD(bus_write_ivar, iicbus_write_ivar), DEVMETHOD(iicbus_transfer, iicbus_transfer_gen), DEVMETHOD_END }; driver_t iicbus_driver = { "iicbus", iicbus_methods, sizeof(struct iicbus_softc), }; static int iicbus_probe(device_t dev) { device_set_desc(dev, "Philips I2C bus"); /* Allow other subclasses to override this driver. */ return (BUS_PROBE_GENERIC); } #if SCAN_IICBUS static int iic_probe_device(device_t dev, u_char addr) { int count; char byte; if ((addr & 1) == 0) { /* is device writable? */ if (!iicbus_start(dev, addr, 0)) { iicbus_stop(dev); return (1); } } else { /* is device readable? */ if (!iicbus_block_read(dev, addr, &byte, 1, &count)) return (1); } return (0); } #endif /* * We add all the devices which we know about. * The generic attach routine will attach them if they are alive. */ static int iicbus_attach(device_t dev) { int error; #if SCAN_IICBUS unsigned char addr; #endif error = iicbus_reset(dev, IIC_FASTEST, 0, NULL); if (error) return (error); /* device probing is meaningless since the bus is supposed to be * hot-plug. Moreover, some I2C chips do not appreciate random * accesses like stop after start to fast, reads for less than * x bytes... */ #if SCAN_IICBUS kprintf("Probing for devices on iicbus%d:", device_get_unit(dev)); /* probe any devices */ for (addr = 16; addr < 240; addr++) { if (iic_probe_device(dev, (u_char)addr)) { kprintf(" <%x>", addr); } } kprintf("\n"); #endif /* * Create the well-known rendezvous children, GUARDED: children * survive driver detach (devclass_delete_driver() only detaches * them), so an unguarded re-attach leaks a struct bsd_device * trio per unload/reload cycle and mints duplicate iicN/iicsmbN * units (duplicate /dev/iicN nodes on one physical bus). * Route through our own bus_add_child so ivars are allocated. */ if (device_find_child(dev, "ic", -1) == NULL) BUS_ADD_CHILD(dev, dev, 0, "ic", -1); if (device_find_child(dev, "iic", -1) == NULL) BUS_ADD_CHILD(dev, dev, 0, "iic", -1); if (device_find_child(dev, "iicsmb", -1) == NULL) BUS_ADD_CHILD(dev, dev, 0, "iicsmb", -1); #if 0 /* attach any known device */ device_add_child(dev, "iic", -1); #endif bus_generic_attach(dev); return (0); } static int iicbus_detach(device_t dev) { int error; /* * DF-5635: a failing child detach must fail OUR detach, else the * bus is left marked detached + driverless with its softc freed * (device_set_driver(NULL) kfrees dev->softc) while the child is * still attached -- the child then derefs * device_get_softc(bus) == NULL in iicbus_request_bus(). * * DF-5563 note: the waiter wake/drain this detach also owes * (dying flag + wakeup(sc) + drain loop) is carried by that * finding's fix; both patches compose trivially here. */ error = iicbus_reset(dev, IIC_FASTEST, 0, NULL); if (error) return (error); error = bus_generic_detach(dev); return (error); } /* * DF-5632: DragonFly's bus_add_child interface is * device_t add_child(device_t bus, device_t parent, int order, * const char *name, int unit) * (sys/kern/bus_if.m:128-134). The old 4-arg/int-registered prototype * made every dispatch misread its arguments (order <- child pointer, * name <- order int, unit <- name pointer) and return NULL to callers * expecting the new device. DF-5634: allocate the ivar the generated * accessors (iicbus.h:53-56) read/write; free it in child_detached. */ static device_t iicbus_add_child(device_t bus, device_t parent, int order, const char *name, int unit) { struct iicbus_ivar *ivar; device_t child; child = device_add_child_ordered(parent, order, name, unit); if (child == NULL) return (NULL); ivar = kmalloc(sizeof(*ivar), M_DEVBUF, M_INTWAIT | M_ZERO); if (ivar == NULL) { device_delete_child(bus, child); return (NULL); } device_set_ivars(child, ivar); return (child); } static void iicbus_child_detached(device_t bus, device_t child) { struct iicbus_ivar *ivar = IICBUS_IVAR(child); if (ivar != NULL) { device_set_ivars(child, NULL); kfree(ivar, M_DEVBUF); } } static int iicbus_read_ivar(device_t dev, device_t child, int index, uintptr_t *result) { struct iicbus_ivar *ivar = IICBUS_IVAR(child); switch (index) { case IICBUS_IVAR_ADDR: *result = (ivar != NULL) ? ivar->addr : 0; return (0); default: return (ENOENT); } } static int iicbus_write_ivar(device_t dev, device_t child, int index, uintptr_t value) { struct iicbus_ivar *ivar = IICBUS_IVAR(child); switch (index) { case IICBUS_IVAR_ADDR: if (ivar != NULL) ivar->addr = (uint32_t)value; return (0); default: return (ENOENT); } } int iicbus_generic_intr(device_t dev, int event, char *buf) { return (0); } int iicbus_null_callback(device_t dev, int index, caddr_t data) { return (0); } int iicbus_null_repeated_start(device_t dev, u_char addr) { return (IIC_ENOTSUPP); } DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, NULL, NULL); MODULE_VERSION(iicbus, IICBUS_MODVER);