freebsd-dev/sys/dev/iicbus/iicoc.c
Jean-Sébastien Pédron 238b89fcad iicbus: Use device_delete_children() instead of explicit child removal
If the bus is detached and deleted by a call to device_delete_child() or
device_delete_children() on a device higher in the tree, I²C children
were already detached and deleted. So the device_t pointer stored in sc
points to freed memory: we must not try to delete it again.

By using device_delete_children(), we let subr_bus.c figure out if there
are children to take care of.

While here, make sure iicbus_detach() and iicoc_detach() call
device_delete_children() too, to be safe.

Reviewed by:	jhb, imp
Approved by:	jhb, imp
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D3926
2015-10-20 19:52:59 +00:00

392 lines
9.3 KiB
C

/*-
* Copyright (c) 2003-2012 Broadcom Corporation
* 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 BROADCOM ``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 BROADCOM 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iicoc.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include "iicbus_if.h"
static devclass_t iicoc_devclass;
/*
* Device methods
*/
static int iicoc_probe(device_t);
static int iicoc_attach(device_t);
static int iicoc_detach(device_t);
static int iicoc_start(device_t dev, u_char slave, int timeout);
static int iicoc_stop(device_t dev);
static int iicoc_read(device_t dev, char *buf,
int len, int *read, int last, int delay);
static int iicoc_write(device_t dev, const char *buf,
int len, int *sent, int timeout);
static int iicoc_repeated_start(device_t dev, u_char slave, int timeout);
struct iicoc_softc {
device_t dev; /* Self */
u_int reg_shift; /* Chip specific */
u_int clockfreq;
u_int i2cfreq;
struct resource *mem_res; /* Memory resource */
int mem_rid;
int sc_started;
uint8_t i2cdev_addr;
device_t iicbus;
struct mtx sc_mtx;
};
static void
iicoc_dev_write(device_t dev, int reg, int value)
{
struct iicoc_softc *sc;
sc = device_get_softc(dev);
bus_write_1(sc->mem_res, reg<<sc->reg_shift, value);
}
static int
iicoc_dev_read(device_t dev, int reg)
{
uint8_t val;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
val = bus_read_1(sc->mem_res, reg<<sc->reg_shift);
return (val);
}
static int
iicoc_wait_on_status(device_t dev, uint8_t bit)
{
int tries = I2C_TIMEOUT;
uint8_t status;
do {
status = iicoc_dev_read(dev, OC_I2C_STATUS_REG);
} while ((status & bit) != 0 && --tries > 0);
return (tries == 0 ? -1: 0);
}
static int
iicoc_rd_cmd(device_t dev, uint8_t cmd)
{
uint8_t data;
iicoc_dev_write(dev, OC_I2C_CMD_REG, cmd);
if (iicoc_wait_on_status(dev, OC_STATUS_TIP) < 0) {
device_printf(dev, "read: Timeout waiting for TIP clear.\n");
return (-1);
}
data = iicoc_dev_read(dev, OC_I2C_DATA_REG);
return (data);
}
static int
iicoc_wr_cmd(device_t dev, uint8_t data, uint8_t cmd)
{
iicoc_dev_write(dev, OC_I2C_DATA_REG, data);
iicoc_dev_write(dev, OC_I2C_CMD_REG, cmd);
if (iicoc_wait_on_status(dev, OC_STATUS_TIP) < 0) {
device_printf(dev, "write: Timeout waiting for TIP clear.\n");
return (-1);
}
return (0);
}
static int
iicoc_wr_ack_cmd(device_t dev, uint8_t data, uint8_t cmd)
{
if (iicoc_wr_cmd(dev, data, cmd) < 0)
return (-1);
if (iicoc_dev_read(dev, OC_I2C_STATUS_REG) & OC_STATUS_NACK) {
device_printf(dev, "write: I2C command ACK Error.\n");
return (IIC_ENOACK);
}
return (0);
}
static int
iicoc_init(device_t dev)
{
struct iicoc_softc *sc;
int value;
sc = device_get_softc(dev);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
iicoc_dev_write(dev, OC_I2C_CTRL_REG,
value & ~(OC_CONTROL_EN | OC_CONTROL_IEN));
value = (sc->clockfreq/(5 * sc->i2cfreq)) - 1;
iicoc_dev_write(dev, OC_I2C_PRESCALE_LO_REG, value & 0xff);
iicoc_dev_write(dev, OC_I2C_PRESCALE_HI_REG, value >> 8);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
iicoc_dev_write(dev, OC_I2C_CTRL_REG, value | OC_CONTROL_EN);
value = iicoc_dev_read(dev, OC_I2C_CTRL_REG);
/* return 0 on success, 1 on error */
return ((value & OC_CONTROL_EN) == 0);
}
static int
iicoc_probe(device_t dev)
{
struct iicoc_softc *sc;
sc = device_get_softc(dev);
if ((pci_get_vendor(dev) == 0x184e) &&
(pci_get_device(dev) == 0x1011)) {
sc->clockfreq = XLP_I2C_CLKFREQ;
sc->i2cfreq = XLP_I2C_FREQ;
sc->reg_shift = 2;
device_set_desc(dev, "Netlogic XLP I2C Controller");
return (BUS_PROBE_DEFAULT);
}
return (ENXIO);
}
/*
* We add all the devices which we know about.
* The generic attach routine will attach them if they are alive.
*/
static int
iicoc_attach(device_t dev)
{
int bus;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
bus = device_get_unit(dev);
sc->dev = dev;
mtx_init(&sc->sc_mtx, "iicoc", "iicoc", MTX_DEF);
sc->mem_rid = 0;
sc->mem_res = bus_alloc_resource(dev,
SYS_RES_MEMORY, &sc->mem_rid, 0ul, ~0ul, 0x100, RF_ACTIVE);
if (sc->mem_res == NULL) {
device_printf(dev, "Could not allocate bus resource.\n");
return (-1);
}
iicoc_init(dev);
sc->iicbus = device_add_child(dev, "iicbus", -1);
if (sc->iicbus == NULL) {
device_printf(dev, "Could not allocate iicbus instance.\n");
return (-1);
}
bus_generic_attach(dev);
return (0);
}
static int
iicoc_detach(device_t dev)
{
bus_generic_detach(dev);
device_delete_children(dev);
return (0);
}
static int
iicoc_start(device_t dev, u_char slave, int timeout)
{
int error = IIC_EBUSERR;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
sc->i2cdev_addr = (slave >> 1);
/* Verify the bus is idle */
if (iicoc_wait_on_status(dev, OC_STATUS_BUSY) < 0)
goto i2c_stx_error;
/* Write Slave Address */
if (iicoc_wr_ack_cmd(dev, slave, OC_COMMAND_START)) {
device_printf(dev,
"I2C write slave address [0x%x] failed.\n", slave);
error = IIC_ENOACK;
goto i2c_stx_error;
}
/* Verify Arbitration is not Lost */
if (iicoc_dev_read(dev, OC_I2C_STATUS_REG) & OC_STATUS_AL) {
device_printf(dev, "I2C Bus Arbitration Lost, Aborting.\n");
error = IIC_EBUSERR;
goto i2c_stx_error;
}
error = IIC_NOERR;
mtx_unlock(&sc->sc_mtx);
return (error);
i2c_stx_error:
iicoc_dev_write(dev, OC_I2C_CMD_REG, OC_COMMAND_STOP);
iicoc_wait_on_status(dev, OC_STATUS_BUSY); /* wait for idle */
mtx_unlock(&sc->sc_mtx);
return (error);
}
static int
iicoc_stop(device_t dev)
{
int error = 0;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
iicoc_dev_write(dev, OC_I2C_CMD_REG, OC_COMMAND_STOP);
iicoc_wait_on_status(dev, OC_STATUS_BUSY); /* wait for idle */
mtx_unlock(&sc->sc_mtx);
return (error);
}
static int
iicoc_write(device_t dev, const char *buf, int len,
int *sent, int timeout /* us */ )
{
uint8_t value;
int i;
value = buf[0];
/* Write Slave Offset */
if (iicoc_wr_ack_cmd(dev, value, OC_COMMAND_WRITE)) {
device_printf(dev, "I2C write slave offset failed.\n");
goto i2c_tx_error;
}
for (i = 1; i < len; i++) {
/* Write data byte */
value = buf[i];
if (iicoc_wr_cmd(dev, value, OC_COMMAND_WRITE)) {
device_printf(dev, "I2C write data byte %d failed.\n",
i);
goto i2c_tx_error;
}
}
*sent = len;
return (IIC_NOERR);
i2c_tx_error:
return (IIC_EBUSERR);
}
static int
iicoc_read(device_t dev, char *buf, int len, int *read, int last,
int delay)
{
int data, i;
uint8_t cmd;
for (i = 0; i < len; i++) {
/* Read data byte */
cmd = (i == len - 1) ? OC_COMMAND_RDNACK : OC_COMMAND_READ;
data = iicoc_rd_cmd(dev, cmd);
if (data < 0) {
device_printf(dev,
"I2C read data byte %d failed.\n", i);
goto i2c_rx_error;
}
buf[i] = (uint8_t)data;
}
*read = len;
return (IIC_NOERR);
i2c_rx_error:
return (IIC_EBUSERR);
}
static int
iicoc_reset(device_t dev, u_char speed, u_char addr, u_char *oldadr)
{
int error;
struct iicoc_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->sc_mtx);
error = iicoc_init(dev);
mtx_unlock(&sc->sc_mtx);
return (error);
}
static int
iicoc_repeated_start(device_t dev, u_char slave, int timeout)
{
return 0;
}
static device_method_t iicoc_methods[] = {
/* device interface */
DEVMETHOD(device_probe, iicoc_probe),
DEVMETHOD(device_attach, iicoc_attach),
DEVMETHOD(device_detach, iicoc_detach),
/* iicbus interface */
DEVMETHOD(iicbus_callback, iicbus_null_callback),
DEVMETHOD(iicbus_repeated_start, iicoc_repeated_start),
DEVMETHOD(iicbus_start, iicoc_start),
DEVMETHOD(iicbus_stop, iicoc_stop),
DEVMETHOD(iicbus_reset, iicoc_reset),
DEVMETHOD(iicbus_write, iicoc_write),
DEVMETHOD(iicbus_read, iicoc_read),
DEVMETHOD(iicbus_transfer, iicbus_transfer_gen),
DEVMETHOD_END
};
static driver_t iicoc_driver = {
"iicoc",
iicoc_methods,
sizeof(struct iicoc_softc),
};
DRIVER_MODULE(iicoc, pci, iicoc_driver, iicoc_devclass, 0, 0);
DRIVER_MODULE(iicbus, iicoc, iicbus_driver, iicbus_devclass, 0, 0);