freebsd-nq/sys/dev/ichiic/ig4_pci.c
Andriy Gapon 448897d366 add iic interface to ig4 driver, move isl and cyapa to iicbus
Summary:
The hardware does not expose a classic SMBus interface.
Instead it has a lower level interface that can express a far richer
I2C protocol than what smbus offers.  However, the interface does not
provide a way to explicitly generate the I2C stop and start conditions.
It's only possible to request that the stop condition is generated
after transferring the next byte in either direction.  So, at least
one data byte must always be transferred.
Thus, some I2C sequences are impossible to generate, e.g., an equivalent
of smbus quick command (<start>-<slave addr>-<r/w bit>-<stop>).

At the same time isl(4) and cyapa(4) are moved to iicbus and now they use
iicbus_transfer for communication.  Previously they used smbus_trans()
interface that is not defined by the SMBus protocol and was implemented
only by ig4(4).  In fact, that interface was impossible to implement
for the typical SMBus controllers like intpm(4) or ichsmb(4) where
a type of the SMBus command must be programmed.

The plan is to remove smbus_trans() and all its uses.
As an aside, the smbus_trans() method deviates from the standard,
but perhaps backwards, FreeBSD convention of using 8-bit slave
addresses (shifted by 1 bit to the left).  The method expects
7-bit addresses.

There is a user facing consequence of this change.
A user must now provide device hints for isl and cyapa that specify an iicbus to use
and a slave address on it.
On Chromebook hardware where isl and cyapa devices are commonly found
it is also possible to use a new chromebook_platform(4) driver that
automatically configures isl and cyapa devices.  There is no need to
provide the device hints in that case,

Right now smbus(4) driver tries to discover all slaves on the bus.
That is very dangerous.  Fortunately, the probing code uses smbus_trans()
to do its job, so it is really enabled for ig4 only.
The plan is to remove that auto-probing code and smbus_trans().

Tested by:	grembo, Matthias Apitz <guru@unixarea.de> (w/o
		chromebook_platform)
Discussed with:	grembo, imp
Reviewed by:	wblock (docs)
MFC after:	1 month
Relnotes:	yes
Differential Revision: https://reviews.freebsd.org/D8172
2016-10-30 12:15:33 +00:00

205 lines
5.8 KiB
C

/*
* Copyright (c) 2014 The DragonFly Project. All rights reserved.
*
* This code is derived from software contributed to The DragonFly Project
* by Matthew Dillon <dillon@backplane.com> and was subsequently ported
* to FreeBSD by Michael Gmelin <freebsd@grem.de>
*
* 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.
* 3. Neither the name of The DragonFly Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific, prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDERS 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Intel fourth generation mobile cpus integrated I2C device, smbus driver.
*
* See ig4_reg.h for datasheet reference and notes.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/errno.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/syslog.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/smbus/smbconf.h>
#include <dev/iicbus/iiconf.h>
#include "smbus_if.h"
#include <dev/ichiic/ig4_reg.h>
#include <dev/ichiic/ig4_var.h>
static int ig4iic_pci_detach(device_t dev);
#define PCI_CHIP_LYNXPT_LP_I2C_1 0x9c618086
#define PCI_CHIP_LYNXPT_LP_I2C_2 0x9c628086
static int
ig4iic_pci_probe(device_t dev)
{
switch(pci_get_devid(dev)) {
case PCI_CHIP_LYNXPT_LP_I2C_1:
device_set_desc(dev, "Intel Lynx Point-LP I2C Controller-1");
break;
case PCI_CHIP_LYNXPT_LP_I2C_2:
device_set_desc(dev, "Intel Lynx Point-LP I2C Controller-2");
break;
default:
return (ENXIO);
}
return (BUS_PROBE_DEFAULT);
}
static int
ig4iic_pci_attach(device_t dev)
{
ig4iic_softc_t *sc = device_get_softc(dev);
int error;
bzero(sc, sizeof(*sc));
mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_DEF);
sx_init(&sc->call_lock, "IG4 call lock");
sc->dev = dev;
sc->regs_rid = PCIR_BAR(0);
sc->regs_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->regs_rid, RF_ACTIVE);
if (sc->regs_res == NULL) {
device_printf(dev, "unable to map registers\n");
ig4iic_pci_detach(dev);
return (ENXIO);
}
sc->intr_rid = 0;
if (pci_alloc_msi(dev, &sc->intr_rid)) {
device_printf(dev, "Using MSI\n");
}
sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
&sc->intr_rid, RF_SHAREABLE | RF_ACTIVE);
if (sc->intr_res == NULL) {
device_printf(dev, "unable to map interrupt\n");
ig4iic_pci_detach(dev);
return (ENXIO);
}
sc->pci_attached = 1;
error = ig4iic_attach(sc);
if (error)
ig4iic_pci_detach(dev);
return (error);
}
static int
ig4iic_pci_detach(device_t dev)
{
ig4iic_softc_t *sc = device_get_softc(dev);
int error;
if (sc->pci_attached) {
error = ig4iic_detach(sc);
if (error)
return (error);
sc->pci_attached = 0;
}
if (sc->intr_res) {
bus_release_resource(dev, SYS_RES_IRQ,
sc->intr_rid, sc->intr_res);
sc->intr_res = NULL;
}
if (sc->intr_rid != 0)
pci_release_msi(dev);
if (sc->regs_res) {
bus_release_resource(dev, SYS_RES_MEMORY,
sc->regs_rid, sc->regs_res);
sc->regs_res = NULL;
}
if (mtx_initialized(&sc->io_lock)) {
mtx_destroy(&sc->io_lock);
sx_destroy(&sc->call_lock);
}
return (0);
}
static device_method_t ig4iic_pci_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ig4iic_pci_probe),
DEVMETHOD(device_attach, ig4iic_pci_attach),
DEVMETHOD(device_detach, ig4iic_pci_detach),
/* SMBus methods from ig4_smb.c */
DEVMETHOD(smbus_callback, ig4iic_smb_callback),
DEVMETHOD(smbus_quick, ig4iic_smb_quick),
DEVMETHOD(smbus_sendb, ig4iic_smb_sendb),
DEVMETHOD(smbus_recvb, ig4iic_smb_recvb),
DEVMETHOD(smbus_writeb, ig4iic_smb_writeb),
DEVMETHOD(smbus_writew, ig4iic_smb_writew),
DEVMETHOD(smbus_readb, ig4iic_smb_readb),
DEVMETHOD(smbus_readw, ig4iic_smb_readw),
DEVMETHOD(smbus_pcall, ig4iic_smb_pcall),
DEVMETHOD(smbus_bwrite, ig4iic_smb_bwrite),
DEVMETHOD(smbus_bread, ig4iic_smb_bread),
DEVMETHOD(smbus_trans, ig4iic_smb_trans),
DEVMETHOD(iicbus_transfer, ig4iic_transfer),
DEVMETHOD(iicbus_reset, ig4iic_reset),
DEVMETHOD(iicbus_callback, iicbus_null_callback),
DEVMETHOD_END
};
static driver_t ig4iic_pci_driver = {
"ig4iic",
ig4iic_pci_methods,
sizeof(struct ig4iic_softc)
};
static devclass_t ig4iic_pci_devclass;
DRIVER_MODULE_ORDERED(ig4iic, pci, ig4iic_pci_driver, ig4iic_pci_devclass, 0, 0,
SI_ORDER_ANY);
MODULE_DEPEND(ig4iic, pci, 1, 1, 1);
MODULE_DEPEND(ig4iic, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(ig4iic, 1);