/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* pcf8584.c is the nexus driver for all pcf8584 controller
* implementations. It supports both interrupt and polled
* mode operation, but defaults to interrupt.
*/
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/open.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/sunndi.h>
#include <sys/modctl.h>
#include <sys/stat.h>
#include <sys/kmem.h>
#include <sys/archsystm.h>
#include <sys/platform_module.h>
#include <sys/i2c/clients/i2c_client.h>
#include <sys/i2c/misc/i2c_svc.h>
#include <sys/i2c/misc/i2c_svc_impl.h>
#include <sys/i2c/nexus/pcf8584.h>
#include <sys/note.h>
/*
* static function declarations
*/
static void pcf8584_resume(dev_info_t *dip);
static void pcf8584_suspend(dev_info_t *dip);
static int pcf8584_bus_ctl(dev_info_t *dip, dev_info_t *rdip,
ddi_ctl_enum_t op, void *arg, void *result);
static void pcf8584_acquire(pcf8584_t *, dev_info_t *dip,
i2c_transfer_t *tp, boolean_t force);
static void pcf8584_release(pcf8584_t *, boolean_t force);
static int pcf8584_attach(dev_info_t *dip, ddi_attach_cmd_t cmd);
static int pcf8584_detach(dev_info_t *dip, ddi_detach_cmd_t cmd);
static int pcf8584_open(dev_t *devp, int flag, int otyp,
cred_t *cred_p);
static int pcf8584_close(dev_t dev, int flag, int otyp,
cred_t *cred_p);
static int pcf8584_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);
static void pcf8584_select_bus(pcf8584_t *i2c);
static enum tran_state pcf8584_type_to_state(int i2c_flags);
static void pcf8584_put_s1(pcf8584_t *i2c, char cmd);
static void pcf8584_put_s0(pcf8584_t *i2c, char data);
static uint8_t pcf8584_get_s0(pcf8584_t *i2c);
static uint8_t pcf8584_get_s1(pcf8584_t *i2c);
static int pcf8584_bbn_ready(pcf8584_t *i2c);
static int pcf8584_error(int status, uint8_t rdwr, pcf8584_t *i2c);
static void pcf8584_monitor_mode(pcf8584_t *i2c);
static int pcf8584_initchild(dev_info_t *cdip);
static void pcf8584_uninitchild(dev_info_t *cdip);
static void pcf8584_init(pcf8584_t *i2c);
static int pcf8584_setup_regs(dev_info_t *dip, pcf8584_t *i2c);
static void pcf8584_free_regs(pcf8584_t *i2c);
static void pcf8584_reportdev(dev_info_t *dip, dev_info_t *rdip);
static int pcf8584_dip_to_addr(dev_info_t *dip);
static uint_t pcf8584_intr(caddr_t arg);
static int pcf8584_process(pcf8584_t *i2c, uint8_t s1);
int pcf8584_transfer(dev_info_t *dip, i2c_transfer_t *tp);
static void pcf8584_do_polled_io(pcf8584_t *i2c);
static void pcf8584_take_over(pcf8584_t *i2c, dev_info_t *dip,
i2c_transfer_t *tp, kcondvar_t **waiter, int *saved_mode);
static void pcf8584_give_up(pcf8584_t *i2c, kcondvar_t *waiter, int saved_mode);
static struct bus_ops pcf8584_busops = {
BUSO_REV,
nullbusmap, /* bus_map */
NULL, /* bus_get_intrspec */
NULL, /* bus_add_intrspec */
NULL, /* bus_remove_intrspec */
NULL, /* bus_map_fault */
ddi_no_dma_map, /* bus_dma_map */
ddi_no_dma_allochdl, /* bus_dma_allochdl */
ddi_no_dma_freehdl, /* bus_dma_freehdl */
ddi_no_dma_bindhdl, /* bus_dma_bindhdl */
ddi_no_dma_unbindhdl, /* bus_unbindhdl */
ddi_no_dma_flush, /* bus_dma_flush */
ddi_no_dma_win, /* bus_dma_win */
ddi_no_dma_mctl, /* bus_dma_ctl */
pcf8584_bus_ctl, /* bus_ctl */
ddi_bus_prop_op, /* bus_prop_op */
NULL, /* bus_get_eventcookie */
NULL, /* bus_add_eventcall */
NULL, /* bus_remove_eventcall */
NULL, /* bus_post_event */
0, /* bus_intr_ctl */
0, /* bus_config */
0, /* bus_unconfig */
0, /* bus_fm_init */
0, /* bus_fm_fini */
0, /* bus_fm_access_enter */
0, /* bus_fm_access_exit */
0, /* bus_power */
i_ddi_intr_ops /* bus_intr_op */
};
struct cb_ops pcf8584_cb_ops = {
pcf8584_open, /* open */
pcf8584_close, /* close */
nodev, /* strategy */
nodev, /* print */
nodev, /* dump */
nodev, /* read */
nodev, /* write */
pcf8584_ioctl, /* ioctl */
nodev, /* devmap */
nodev, /* mmap */
nodev, /* segmap */
nochpoll, /* poll */
ddi_prop_op, /* cb_prop_op */
0, /* streamtab */
D_MP | D_NEW /* Driver compatibility flag */
};
static struct dev_ops pcf8584_ops = {
DEVO_REV,
0,
ddi_getinfo_1to1,
nulldev,
nulldev,
pcf8584_attach,
pcf8584_detach,
nodev,
&pcf8584_cb_ops,
&pcf8584_busops,
NULL,
ddi_quiesce_not_supported, /* devo_quiesce */
};
static struct modldrv modldrv = {
&mod_driverops, /* Type of module. This one is a driver */
"I2C Nexus Driver", /* Name of the module. */
&pcf8584_ops, /* driver ops */
};
static struct modlinkage modlinkage = {
MODREV_1,
&modldrv,
NULL
};
/*
* pcf8584 soft state
*/
static void *pcf8584_state;
i2c_nexus_reg_t pcf8584_regvec = {
I2C_NEXUS_REV,
pcf8584_transfer,
};
/*
* The "interrupt_priorities" property is how a driver can specify a SPARC
* PIL level to associate with each of its interrupt properties. Most
* self-identifying busses have a better mechanism for managing this, but I2C
* doesn't.
*/
int pcf8584_pil = PCF8584_PIL;
#ifdef DEBUG
int pcf8584_print_lvl = 0;
static kmutex_t msg_buf_lock;
static char msg_buff[1024];
#define PCF8584_DDB(command) \
do { \
{ command; } \
_NOTE(CONSTANTCONDITION) \
} while (0)
static void
pcf8584_print(int flags, const char *fmt, ...)
{
if (flags & pcf8584_print_lvl) {
va_list ap;
va_start(ap, fmt);
if (pcf8584_print_lvl & PRT_PROM) {
prom_vprintf(fmt, ap);
} else {
mutex_enter(&msg_buf_lock);
(void) vsprintf(msg_buff, fmt, ap);
if (pcf8584_print_lvl & PRT_BUFFONLY) {
cmn_err(CE_CONT, "?%s", msg_buff);
} else {
cmn_err(CE_CONT, "%s", msg_buff);
}
mutex_exit(&msg_buf_lock);
}
va_end(ap);
}
}
#else
#define PCF8584_DDB(command) \
do { \
{ _NOTE(EMPTY); } \
_NOTE(CONSTANTCONDITION) \
} while (0)
#endif
#define PCF8584_IMPL_DELAY(type, delay) \
if (type == PIC16F747) { \
drv_usecwait(delay); \
}
int
_init(void)
{
int status;
status = ddi_soft_state_init(&pcf8584_state, sizeof (pcf8584_t),
PCF8584_INITIAL_SOFT_SPACE);
if (status != 0) {
return (status);
}
if ((status = mod_install(&modlinkage)) != 0) {
ddi_soft_state_fini(&pcf8584_state);
}
return (status);
}
int
_fini(void)
{
int status;
if ((status = mod_remove(&modlinkage)) == 0) {
ddi_soft_state_fini(&pcf8584_state);
}
return (status);
}
/*
* The loadable-module _info(9E) entry point
*/
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
static void
pcf8584_dodetach(dev_info_t *dip)
{
pcf8584_t *i2c;
int instance = ddi_get_instance(dip);
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
if ((i2c->pcf8584_attachflags & ADD_INTR) != 0) {
ddi_remove_intr(dip, 0, i2c->pcf8584_icookie);
}
cv_destroy(&i2c->pcf8584_cv);
if ((i2c->pcf8584_attachflags & IMUTEX) != 0) {
mutex_destroy(&i2c->pcf8584_imutex);
cv_destroy(&i2c->pcf8584_icv);
}
if ((i2c->pcf8584_attachflags & SETUP_REGS) != 0) {
pcf8584_free_regs(i2c);
}
if ((i2c->pcf8584_attachflags & NEXUS_REGISTER) != 0) {
i2c_nexus_unregister(dip);
}
if ((i2c->pcf8584_attachflags & PROP_CREATE) != 0) {
(void) ddi_prop_remove(DDI_DEV_T_NONE, dip,
"interrupt-priorities");
}
if ((i2c->pcf8584_attachflags & MINOR_NODE) != 0) {
ddi_remove_minor_node(dip, NULL);
}
ddi_soft_state_free(pcf8584_state, instance);
}
static int
pcf8584_doattach(dev_info_t *dip)
{
pcf8584_t *i2c;
int instance = ddi_get_instance(dip);
/*
* Allocate soft state structure.
*/
if (ddi_soft_state_zalloc(pcf8584_state, instance) != DDI_SUCCESS) {
return (DDI_FAILURE);
}
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
i2c->pcf8584_dip = dip;
(void) snprintf(i2c->pcf8584_name, sizeof (i2c->pcf8584_name),
"%s_%d", ddi_node_name(dip), instance);
/*
* Identify which pcf8584 implementation is being attached to.
*/
if (strcmp(ddi_binding_name(i2c->pcf8584_dip), "SUNW,bbc-i2c") == 0) {
i2c->pcf8584_impl_type = BBC;
i2c->pcf8584_impl_delay = PCF8584_GENERIC_DELAY;
} else if (strcmp(ddi_binding_name(i2c->pcf8584_dip),
"SUNW,i2c-pic16f747") == 0) {
i2c->pcf8584_impl_type = PIC16F747;
i2c->pcf8584_impl_delay = PCF8584_PIC16F747_DELAY;
} else {
i2c->pcf8584_impl_type = GENERIC;
i2c->pcf8584_impl_delay = PCF8584_GENERIC_DELAY;
}
if (ddi_prop_exists(DDI_DEV_T_ANY, dip,
DDI_PROP_NOTPROM | DDI_PROP_DONTPASS,
"interrupt-priorities") != 1) {
(void) ddi_prop_create(DDI_DEV_T_NONE, dip,
DDI_PROP_CANSLEEP, "interrupt-priorities",
(caddr_t)&pcf8584_pil,
sizeof (pcf8584_pil));
i2c->pcf8584_attachflags |= PROP_CREATE;
}
cv_init(&i2c->pcf8584_cv, NULL, CV_DRIVER, NULL);
if (pcf8584_setup_regs(dip, i2c) != DDI_SUCCESS) {
goto bad;
}
i2c->pcf8584_attachflags |= SETUP_REGS;
if (ddi_prop_exists(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS |
DDI_PROP_CANSLEEP, "poll-mode") == 1) {
i2c->pcf8584_mode = PCF8584_POLL_MODE;
} else {
if (ddi_get_iblock_cookie(dip, 0,
&i2c->pcf8584_icookie) == DDI_SUCCESS) {
mutex_init(&i2c->pcf8584_imutex, NULL, MUTEX_DRIVER,
(void *)i2c->pcf8584_icookie);
cv_init(&i2c->pcf8584_icv, NULL, CV_DRIVER, NULL);
i2c->pcf8584_attachflags |= IMUTEX;
if (ddi_add_intr(dip, 0, NULL, NULL, pcf8584_intr,
(caddr_t)i2c) == DDI_SUCCESS) {
i2c->pcf8584_attachflags |= ADD_INTR;
i2c->pcf8584_mode = PCF8584_INTR_MODE;
} else {
cmn_err(CE_WARN, "%s failed to add interrupt",
i2c->pcf8584_name);
i2c->pcf8584_mode = PCF8584_POLL_MODE;
}
} else {
cmn_err(CE_WARN, "%s failed to retrieve iblock cookie. "
"Operating in POLL MODE only", i2c->pcf8584_name);
i2c->pcf8584_mode = PCF8584_POLL_MODE;
}
}
/*
* For polled mode, still initialize a cv and mutex
*/
if ((i2c->pcf8584_attachflags & IMUTEX) == 0) {
cv_init(&i2c->pcf8584_icv, NULL, CV_DRIVER, NULL);
mutex_init(&i2c->pcf8584_imutex, NULL, MUTEX_DRIVER, NULL);
i2c->pcf8584_attachflags |= IMUTEX;
}
i2c_nexus_register(dip, &pcf8584_regvec);
i2c->pcf8584_attachflags |= NEXUS_REGISTER;
if (ddi_create_minor_node(dip, "devctl", S_IFCHR, instance,
DDI_NT_NEXUS, 0) == DDI_FAILURE) {
cmn_err(CE_WARN, "%s ddi_create_minor_node failed",
i2c->pcf8584_name);
goto bad;
}
i2c->pcf8584_attachflags |= MINOR_NODE;
pcf8584_init(i2c);
i2c->pcf8584_nexus_dip = dip;
return (DDI_SUCCESS);
bad:
pcf8584_dodetach(dip);
return (DDI_FAILURE);
}
static int
pcf8584_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
switch (cmd) {
case DDI_ATTACH:
return (pcf8584_doattach(dip));
case DDI_RESUME:
pcf8584_resume(dip);
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
}
static int
pcf8584_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
switch (cmd) {
case DDI_DETACH:
pcf8584_dodetach(dip);
return (DDI_SUCCESS);
case DDI_SUSPEND:
pcf8584_suspend(dip);
return (DDI_SUCCESS);
default:
return (DDI_FAILURE);
}
}
/*ARGSUSED*/
static int
pcf8584_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
{
int instance;
pcf8584_t *i2c;
/*
* Make sure the open is for the right file type
*/
if (otyp != OTYP_CHR)
return (EINVAL);
instance = getminor(*devp);
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
if (i2c == NULL)
return (ENXIO);
/*
* Enforce exclusive access
*/
mutex_enter(&i2c->pcf8584_imutex);
if (i2c->pcf8584_open) {
mutex_exit(&i2c->pcf8584_imutex);
return (EBUSY);
} else
i2c->pcf8584_open = 1;
mutex_exit(&i2c->pcf8584_imutex);
return (0);
}
/*ARGSUSED*/
static int
pcf8584_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
{
int instance;
pcf8584_t *i2c;
/*
* Make sure the close is for the right file type
*/
if (otyp != OTYP_CHR)
return (EINVAL);
instance = getminor(dev);
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
if (i2c == NULL)
return (ENXIO);
mutex_enter(&i2c->pcf8584_imutex);
i2c->pcf8584_open = 0;
mutex_exit(&i2c->pcf8584_imutex);
return (0);
}
/*ARGSUSED*/
static int
pcf8584_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp,
int *rvalp)
{
pcf8584_t *i2c;
dev_info_t *self;
struct devctl_iocdata *dcp;
int rv;
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, getminor(dev));
if (i2c == NULL)
return (ENXIO);
self = (dev_info_t *)i2c->pcf8584_nexus_dip;
/*
* read devctl ioctl data
*/
if (ndi_dc_allochdl((void *)arg, &dcp) != NDI_SUCCESS) {
return (EFAULT);
}
switch (cmd) {
case DEVCTL_BUS_DEV_CREATE:
rv = ndi_dc_devi_create(dcp, self, 0, NULL);
break;
case DEVCTL_DEVICE_REMOVE:
rv = ndi_devctl_device_remove(self, dcp, 0);
break;
default:
rv = ENOTSUP;
}
ndi_dc_freehdl(dcp);
return (rv);
}
static int
pcf8584_bus_ctl(dev_info_t *dip, dev_info_t *rdip, ddi_ctl_enum_t op,
void *arg, void *result)
{
switch (op) {
case DDI_CTLOPS_INITCHILD:
return (pcf8584_initchild((dev_info_t *)arg));
case DDI_CTLOPS_UNINITCHILD:
pcf8584_uninitchild((dev_info_t *)arg);
return (DDI_SUCCESS);
case DDI_CTLOPS_REPORTDEV:
pcf8584_reportdev(dip, rdip);
return (DDI_SUCCESS);
case DDI_CTLOPS_DMAPMAPC:
case DDI_CTLOPS_POKE:
case DDI_CTLOPS_PEEK:
case DDI_CTLOPS_IOMIN:
case DDI_CTLOPS_REPORTINT:
case DDI_CTLOPS_SIDDEV:
case DDI_CTLOPS_SLAVEONLY:
case DDI_CTLOPS_AFFINITY:
case DDI_CTLOPS_PTOB:
case DDI_CTLOPS_BTOP:
case DDI_CTLOPS_BTOPR:
case DDI_CTLOPS_DVMAPAGESIZE:
return (DDI_FAILURE);
default:
return (ddi_ctlops(dip, rdip, op, arg, result));
}
}
/*
* pcf8584_suspend() is called before the system suspends. Existing
* transfer in progress or waiting will complete, but new transfers are
* effectively blocked by "acquiring" the bus.
*/
static void
pcf8584_suspend(dev_info_t *dip)
{
pcf8584_t *i2c;
int instance;
instance = ddi_get_instance(dip);
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
pcf8584_acquire(i2c, NULL, NULL, B_FALSE);
}
/*
* pcf8584_resume() is called when the system resumes from CPR. It releases
* the hold that was placed on the i2c bus, which allows any real
* transfers to continue.
*/
static void
pcf8584_resume(dev_info_t *dip)
{
pcf8584_t *i2c;
int instance;
instance = ddi_get_instance(dip);
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state, instance);
pcf8584_release(i2c, B_FALSE);
pcf8584_init(i2c);
}
/*
* pcf8584_acquire() is called by a thread wishing to "own" the I2C bus.
* It should not be held across multiple transfers. If the 'force' flag
* is set, do not try to acquire mutex or do cv_wait.
*/
static void
pcf8584_acquire(pcf8584_t *i2c, dev_info_t *dip, i2c_transfer_t *tp,
boolean_t force)
{
if (force) {
i2c->pcf8584_busy = 1;
i2c->pcf8584_cur_tran = tp;
i2c->pcf8584_cur_dip = dip;
i2c->pcf8584_cur_status = PCF8584_TRANSFER_NEW;
return;
}
mutex_enter(&i2c->pcf8584_imutex);
while (i2c->pcf8584_busy) {
cv_wait(&i2c->pcf8584_cv, &i2c->pcf8584_imutex);
}
i2c->pcf8584_busy = 1;
mutex_exit(&i2c->pcf8584_imutex);
/*
* On systems where OBP shares a pcf8584 controller with the
* OS, plat_shared_i2c_enter will serialize access to the
* pcf8584 controller. Do not grab this lock during CPR
* suspend as the CPR thread also acquires this muxex
* through through prom_setprop which causes recursive
* mutex enter.
*
* dip == NULL during CPR.
*/
if ((&plat_shared_i2c_enter != NULL) && (dip != NULL)) {
plat_shared_i2c_enter(i2c->pcf8584_dip);
}
mutex_enter(&i2c->pcf8584_imutex);
i2c->pcf8584_cur_tran = tp;
i2c->pcf8584_cur_dip = dip;
mutex_exit(&i2c->pcf8584_imutex);
}
/*
* pcf8584_release() is called to release a hold made by pcf8584_acquire().
*/
static void
pcf8584_release(pcf8584_t *i2c, boolean_t force)
{
if (force) {
i2c->pcf8584_busy = 0;
i2c->pcf8584_cur_tran = NULL;
i2c->pcf8584_cur_dip = NULL;
i2c->pcf8584_cur_status = PCF8584_TRANSFER_OVER;
cv_signal(&i2c->pcf8584_cv);
return;
}
mutex_enter(&i2c->pcf8584_imutex);
i2c->pcf8584_busy = 0;
i2c->pcf8584_cur_tran = NULL;
cv_signal(&i2c->pcf8584_cv);
mutex_exit(&i2c->pcf8584_imutex);
if ((&plat_shared_i2c_exit != NULL) && (i2c->pcf8584_cur_dip != NULL)) {
plat_shared_i2c_exit(i2c->pcf8584_dip);
}
}
/*
* if pcf8584_b_reg exists, it means the current bus controller signals
* are multiplexed into more than a single bus. Select the bus needed
* by writing to the mux register.
*/
static void
pcf8584_select_bus(pcf8584_t *i2c)
{
int bus;
pcf8584_ppvt_t *ppvt;
/*
* The existence of pcf8584_b_reg means the bus registers
* are multiplexed.
*/
PCF8584_DDB(pcf8584_print(PRT_SELECT, "bus multiplex: %X\n",
i2c->pcf8584_b_reg));
if (i2c->pcf8584_b_reg != NULL) {
ppvt = ddi_get_parent_data(i2c->pcf8584_cur_dip);
bus = ppvt->pcf8584_ppvt_bus;
PCF8584_DDB(pcf8584_print(PRT_SELECT,
"transmitting bus number %d\n", bus));
ddi_put8(i2c->pcf8584_b_rhandle, i2c->pcf8584_b_reg, bus);
}
}
/*
* pcf8584_type_to_state() converts a transfer type to the
* next state of the I2C state machine based on the requested
* transfer type.
*/
static enum tran_state
pcf8584_type_to_state(int i2c_flags)
{
switch (i2c_flags) {
case I2C_WR:
return (TRAN_STATE_WR);
case I2C_RD:
return (TRAN_STATE_DUMMY_RD);
case I2C_WR_RD:
return (TRAN_STATE_WR_RD);
}
/*NOTREACHED*/
return (TRAN_STATE_NULL);
}
/*
* pcf8584_put_s1() writes out cmd to register S1.
*/
static void
pcf8584_put_s1(pcf8584_t *i2c, char cmd)
{
ddi_acc_handle_t hp = i2c->pcf8584_rhandle;
pcf8584_regs_t *rp = &i2c->pcf8584_regs;
ddi_put8(hp, rp->pcf8584_regs_s1, cmd);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
/*
* read status to make sure write is flushed
*/
(void) ddi_get8(hp, rp->pcf8584_regs_s1);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
}
/*
* pcf8584_put_s0() writes out data to register S0.
*/
static void
pcf8584_put_s0(pcf8584_t *i2c, char data)
{
ddi_acc_handle_t hp = i2c->pcf8584_rhandle;
pcf8584_regs_t *rp = &i2c->pcf8584_regs;
ddi_put8(hp, rp->pcf8584_regs_s0, data);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
/*
* read status to make sure write is flushed
*/
(void) ddi_get8(hp, rp->pcf8584_regs_s1);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
}
/*
* pcf8584_get_s0() reads from register S0.
*/
static uint8_t
pcf8584_get_s0(pcf8584_t *i2c)
{
ddi_acc_handle_t hp = i2c->pcf8584_rhandle;
pcf8584_regs_t *rp = &i2c->pcf8584_regs;
uint8_t s0;
s0 = ddi_get8(hp, rp->pcf8584_regs_s0);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
return (s0);
}
/*
* pcf8584_get_s1() reads from register S1.
*/
static uint8_t
pcf8584_get_s1(pcf8584_t *i2c)
{
ddi_acc_handle_t hp = i2c->pcf8584_rhandle;
pcf8584_regs_t *rp = &i2c->pcf8584_regs;
uint8_t s1;
s1 = ddi_get8(hp, rp->pcf8584_regs_s1);
PCF8584_IMPL_DELAY(i2c->pcf8584_impl_type,
i2c->pcf8584_impl_delay);
return (s1);
}
/*
* If the previous transaction was a write, the stop
* bit may not make it out on the wire before
* the next transaction startes. And unfortunately, there
* is no interrupt after the stop bit is written, so this
* function will poll to make sure the BBC is ready.
*/
static int
pcf8584_bbn_ready(pcf8584_t *i2c)
{
uint8_t s1;
int usecwaits = 0;
s1 = pcf8584_get_s1(i2c);
while ((s1 & S1_BBN) == 0) {
if (usecwaits++ == 100) {
/* Try initializing the bus */
pcf8584_monitor_mode(i2c);
pcf8584_put_s1(i2c, S1_STOP);
delay(1);
pcf8584_init(i2c);
(void) pcf8584_get_s0(i2c);
s1 = pcf8584_get_s1(i2c);
if (s1 & S1_BBN) {
cmn_err(CE_WARN,
"!%s: cleared bus busy. addr=0x%x",
i2c->pcf8584_name,
pcf8584_dip_to_addr(i2c->pcf8584_cur_dip));
return (I2C_SUCCESS);
} else {
cmn_err(CE_WARN,
"!%s bus busy after init addr=0x%x",
i2c->pcf8584_name,
pcf8584_dip_to_addr(i2c->pcf8584_cur_dip));
return (I2C_FAILURE);
}
}
drv_usecwait(1);
s1 = pcf8584_get_s1(i2c);
}
return (I2C_SUCCESS);
}
static int
pcf8584_error(int status, uint8_t rdwr, pcf8584_t *i2c)
{
int addr = pcf8584_dip_to_addr(i2c->pcf8584_cur_dip);
pcf8584_regs_t *rp = &i2c->pcf8584_regs;
if (status & S1_BER) {
cmn_err(CE_WARN,
"!%s bus error; Controller = 0x%p "
" addr = 0x%x", i2c->pcf8584_name,
(void *)rp->pcf8584_regs_s1, addr);
pcf8584_init(i2c);
return (I2C_FAILURE);
} else if (status & S1_LAB) {
cmn_err(CE_WARN, "!%s lost arbitration; Controller ="
" 0x%p addr = 0x%x", i2c->pcf8584_name,
(void *)rp->pcf8584_regs_s1, addr);
pcf8584_init(i2c);
return (I2C_FAILURE);
} else if ((status & S1_LRB) && (rdwr == I2C_WR)) {
/*
* No error logged here, because this may be benign.
* Cf. the "Alert Response Address" feature of SMBUS.
*/
pcf8584_put_s1(i2c, S1_STOP);
return (I2C_FAILURE);
}
return (I2C_SUCCESS);
}
static void
pcf8584_monitor_mode(pcf8584_t *i2c)
{
pcf8584_put_s1(i2c, S1_PIN);
pcf8584_put_s0(i2c, MONITOR_ADDRESS);
}
static int
pcf8584_initchild(dev_info_t *cdip)
{
int32_t cell_size;
int len;
int32_t regs[2];
int err;
pcf8584_ppvt_t *ppvt;
char name[30];
PCF8584_DDB(pcf8584_print(PRT_INIT, "pcf8584_initchild enter: %s\n",
ddi_node_name(cdip)));
ppvt = kmem_alloc(sizeof (pcf8584_ppvt_t), KM_SLEEP);
len = sizeof (cell_size);
err = ddi_getlongprop_buf(DDI_DEV_T_ANY, cdip,
DDI_PROP_CANSLEEP, "#address-cells",
(caddr_t)&cell_size, &len);
if (err != DDI_PROP_SUCCESS || len != sizeof (cell_size)) {
return (DDI_FAILURE);
}
len = sizeof (regs);
err = ddi_getlongprop_buf(DDI_DEV_T_ANY, cdip,
DDI_PROP_DONTPASS | DDI_PROP_CANSLEEP,
"reg", (caddr_t)regs, &len);
if (err != DDI_PROP_SUCCESS ||
len != (cell_size * sizeof (int32_t))) {
return (DDI_FAILURE);
}
if (cell_size == 1) {
ppvt->pcf8584_ppvt_addr = regs[0];
(void) sprintf(name, "%x", regs[0]);
} else if (cell_size == 2) {
ppvt->pcf8584_ppvt_bus = regs[0];
ppvt->pcf8584_ppvt_addr = regs[1];
(void) sprintf(name, "%x,%x", regs[0], regs[1]);
} else {
return (DDI_FAILURE);
}
ddi_set_parent_data(cdip, ppvt);
ddi_set_name_addr(cdip, name);
PCF8584_DDB(pcf8584_print(PRT_INIT,
"pcf8584_initchild SUCCESS: %s\n", ddi_node_name(cdip)));
return (DDI_SUCCESS);
}
static void
pcf8584_uninitchild(dev_info_t *cdip)
{
pcf8584_ppvt_t *ppvt;
ppvt = ddi_get_parent_data(cdip);
kmem_free(ppvt, sizeof (pcf8584_ppvt_t));
ddi_set_parent_data(cdip, NULL);
ddi_set_name_addr(cdip, NULL);
PCF8584_DDB(pcf8584_print(PRT_INIT, "i2c_uninitchild: %s\n",
ddi_node_name(cdip)));
}
static void
pcf8584_init(pcf8584_t *i2c)
{
uint8_t clk_div = 0x1C;
pcf8584_put_s1(i2c, S1_PIN);
pcf8584_put_s0(i2c, S0_OWN);
pcf8584_put_s1(i2c, S1_PIN | S1_ES1);
/*
* The default case is to set the clock divisor to the least common
* denominator to avoid over clocking the I2C bus. Assume that
* BBC based systems are using the Safari clock as input, so select
* the clk divisor based on it.
*/
if (i2c->pcf8584_impl_type == BBC) {
dev_info_t *root_node;
int clock_freq;
root_node = ddi_root_node();
clock_freq = ddi_prop_get_int(DDI_DEV_T_ANY, root_node,
DDI_PROP_DONTPASS, "clock-frequency", 0);
if (clock_freq < 105000000) {
clk_div = 0x00;
} else if (clock_freq < 160000000) {
clk_div = 0x10;
} else {
clk_div = 0x1C;
}
}
/* set I2C clock speed */
pcf8584_put_s0(i2c, clk_div);
pcf8584_put_s1(i2c, S1_PIN | S1_ESO | S1_ACK);
/*
* Multi-Master: Wait for a period of time equal to the
* longest I2C message. This accounts for the case
* where multiple controllers and, if this particular one
* is "lagging", misses the BB(bus busy) condition.
* We wait 200 ms since the longest transaction at this time
* on the i2c bus is a 256 byte read from the seprom which takes
* about 75 ms. Some additional buffer does no harm to the driver.
*/
delay(drv_usectohz(PCF8584_INIT_WAIT));
}
/*
* pcf8584_setup_regs() is called to map in registers specific to
* the pcf8584.
*/
static int
pcf8584_setup_regs(dev_info_t *dip, pcf8584_t *i2c)
{
int nregs;
ddi_device_acc_attr_t attr;
caddr_t reg_base;
attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
if (ddi_dev_nregs(dip, &nregs) != DDI_SUCCESS) {
return (DDI_FAILURE);
}
if (ddi_regs_map_setup(dip, 0,
(caddr_t *)&reg_base, 0, 0, &attr,
&i2c->pcf8584_rhandle) != DDI_SUCCESS) {
return (DDI_FAILURE);
}
/*
* If i2c controller is on BBC, then s1 comes before s0.
*/
if (i2c->pcf8584_impl_type == BBC) {
i2c->pcf8584_regs.pcf8584_regs_s0 =
(uint8_t *)&reg_base[1];
i2c->pcf8584_regs.pcf8584_regs_s1 =
(uint8_t *)&reg_base[0];
} else {
i2c->pcf8584_regs.pcf8584_regs_s0 =
(uint8_t *)&reg_base[0];
i2c->pcf8584_regs.pcf8584_regs_s1 =
(uint8_t *)&reg_base[1];
}
if (nregs > 1) {
if (ddi_regs_map_setup(dip,
1, (caddr_t *)&i2c->pcf8584_b_reg,
0, 0, &attr, &i2c->pcf8584_b_rhandle) !=
DDI_SUCCESS) {
return (DDI_FAILURE);
}
}
return (DDI_SUCCESS);
}
/*
* pcf8584_free_regs() frees any registers previously
* allocated.
*/
static void
pcf8584_free_regs(pcf8584_t *i2c)
{
if (i2c->pcf8584_regs.pcf8584_regs_s0 != NULL) {
ddi_regs_map_free(&i2c->pcf8584_rhandle);
}
if (i2c->pcf8584_b_reg != NULL) {
ddi_regs_map_free(&i2c->pcf8584_b_rhandle);
}
}
static void
pcf8584_reportdev(dev_info_t *dip, dev_info_t *rdip)
{
pcf8584_ppvt_t *ppvt;
ppvt = ddi_get_parent_data(rdip);
cmn_err(CE_CONT, "?%s%d at %s%d: addr 0x%x",
ddi_driver_name(rdip), ddi_get_instance(rdip),
ddi_driver_name(dip), ddi_get_instance(dip),
ppvt->pcf8584_ppvt_addr);
}
/*
* i2_nexus_dip_to_addr() takes a dip and returns an I2C address.
*/
static int
pcf8584_dip_to_addr(dev_info_t *dip)
{
pcf8584_ppvt_t *ppvt;
ppvt = ddi_get_parent_data(dip);
return (ppvt->pcf8584_ppvt_addr);
}
/*
* pcf8584_intr() is the interrupt service routine registered during
* attach, and remains registered even if the driver is in POLLED mode. So if
* this is called from POLLED mode, it needs to return without doing
* any work to prevent the I2C bus from entering an unknown state.
*/
static uint_t
pcf8584_intr(caddr_t arg)
{
pcf8584_t *i2c = (pcf8584_t *)arg;
uint8_t s1;
ASSERT(i2c->pcf8584_mode != PCF8584_POLL_MODE);
PCF8584_DDB(pcf8584_print(PRT_INTR, "pcf8584_intr: enter\n"));
mutex_enter(&i2c->pcf8584_imutex);
/*
* It is necessary to check both whether the hardware is interrupting
* and that there is a current transaction for the bus in progress.
* Checking just one but not the other will lead to a panic on xcal
* since both controllers share the same ino, and also because OBP
* shares a controller with the kernel even while the kernel is running.
*/
if (i2c->pcf8584_cur_tran == NULL) {
mutex_exit(&i2c->pcf8584_imutex);
return (DDI_INTR_UNCLAIMED);
}
s1 = pcf8584_get_s1(i2c);
if (s1 & S1_PIN) {
mutex_exit(&i2c->pcf8584_imutex);
return (DDI_INTR_UNCLAIMED);
}
if (pcf8584_process(i2c, s1) == I2C_COMPLETE) {
i2c->pcf8584_tran_state = TRAN_STATE_NULL;
i2c->pcf8584_cur_status = PCF8584_TRANSFER_OVER;
cv_signal(&i2c->pcf8584_icv);
} else
i2c->pcf8584_cur_status = PCF8584_TRANSFER_ON;
mutex_exit(&i2c->pcf8584_imutex);
return (DDI_INTR_CLAIMED);
}
/*
* Interrupt occurs after a byte is transmitted or received, indicating
* the device is ready to be serviced.
*/
static int
pcf8584_process(pcf8584_t *i2c, uint8_t s1)
{
i2c_transfer_t *tp = i2c->pcf8584_cur_tran;
int addr = pcf8584_dip_to_addr(i2c->pcf8584_cur_dip);
int dummy_read;
ASSERT(i2c->pcf8584_tran_state != TRAN_STATE_NULL);
switch (i2c->pcf8584_tran_state) {
case TRAN_STATE_DUMMY_DATA:
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_DUMMY DATA: write dummy %x\n", DUMMY_DATA));
if (pcf8584_error(s1, I2C_RD, i2c) != I2C_SUCCESS) {
tp->i2c_result = I2C_FAILURE;
return (I2C_COMPLETE);
}
i2c->pcf8584_tran_state = TRAN_STATE_START;
pcf8584_put_s0(i2c, DUMMY_DATA);
return (I2C_PENDING);
case TRAN_STATE_START:
if (pcf8584_error(s1, I2C_RD, i2c) != I2C_SUCCESS) {
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_START failure\n"));
tp->i2c_result = I2C_FAILURE;
return (I2C_COMPLETE);
}
i2c->pcf8584_tran_state =
pcf8584_type_to_state(tp->i2c_flags);
/* Set read bit if this is a read transaction */
if (tp->i2c_flags == I2C_RD) {
addr |= I2C_READ;
}
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_put_s1(i2c, S1_START2);
else
pcf8584_put_s1(i2c, S1_START2 | S1_ENI);
pcf8584_put_s0(i2c, addr);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_START: write addr: %x\n", addr));
return (I2C_PENDING);
case TRAN_STATE_WR:
if (pcf8584_error(s1, I2C_WR, i2c) != I2C_SUCCESS) {
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR failure\n"));
tp->i2c_result = I2C_FAILURE;
return (I2C_COMPLETE);
}
/* check to see if at end of buffer */
if (tp->i2c_w_resid == 0) {
pcf8584_put_s1(i2c, S1_STOP);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR: write STOP\n"));
return (I2C_COMPLETE);
}
pcf8584_put_s0(i2c, tp->i2c_wbuf[tp->i2c_wlen -
tp->i2c_w_resid--]);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR: write data %x\n",
tp->i2c_wbuf[tp->i2c_wlen - (tp->i2c_w_resid + 1)]));
return (I2C_PENDING);
case TRAN_STATE_DUMMY_RD:
if (pcf8584_error(s1, I2C_WR, i2c) != I2C_SUCCESS) {
tp->i2c_result = I2C_FAILURE;
return (I2C_COMPLETE);
}
/*
* The first read is always a dummy read, because reading S0
* is what starts bit shifting and ACK on the I2c bus.
* This byte is accessed during the next read, which starts
* another 8 bit bus shift.
*
* special case for 1 byte reads: Clear the ACK bit
* here since this read causes the last and only byte
* to be sent on the I2C bus.
*/
if (tp->i2c_r_resid == 1) {
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_put_s1(i2c, S1_ESO);
else
pcf8584_put_s1(i2c, S1_ESO | S1_ENI);
}
/*
* dummy read
*/
dummy_read = pcf8584_get_s0(i2c);
i2c->pcf8584_tran_state = TRAN_STATE_RD;
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_DUMMY_RD: read dummy %d\n", dummy_read));
return (I2C_PENDING);
case TRAN_STATE_RD:
if (pcf8584_error(s1, I2C_RD, i2c) != I2C_SUCCESS) {
tp->i2c_result = I2C_FAILURE;
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_RD failure\n"));
return (I2C_COMPLETE);
}
/*
* If resid == 1, the last byte has already been shifted into
* the accumulator. Send the stop bit. This also prevents the
* last S0 read from shifting in another byte from the I2C bus.
*/
if (tp->i2c_r_resid == 1) {
pcf8584_put_s1(i2c, S1_STOP);
}
/*
* If resid == 2, then the next read will cause the I2C bus to
* start shifting in the last byte on the I2C bus, which we
* don't want to be ACK'd, so clear the ACK bit.
*/
if (tp->i2c_r_resid == 2) {
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_put_s1(i2c, S1_ESO);
else
pcf8584_put_s1(i2c, S1_ESO | S1_ENI);
}
tp->i2c_rbuf[tp->i2c_rlen - tp->i2c_r_resid] =
pcf8584_get_s0(i2c);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_RD: returning. i2c_rlen = %d "
"i2c_r_resid = %d, data =%x\n", tp->i2c_rlen,
tp->i2c_r_resid, tp->i2c_rbuf[tp->i2c_rlen -
tp->i2c_r_resid]));
if (--tp->i2c_r_resid == 0) {
return (I2C_COMPLETE);
}
return (I2C_PENDING);
case TRAN_STATE_WR_RD:
if (pcf8584_error(s1, I2C_WR, i2c) != I2C_SUCCESS) {
tp->i2c_result = I2C_FAILURE;
return (I2C_COMPLETE);
}
if ((s1 & S1_LRB)) {
pcf8584_put_s1(i2c, S1_STOP);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR_RD sending STOP\n"));
return (I2C_COMPLETE);
}
if (tp->i2c_w_resid != 0) {
pcf8584_put_s0(i2c, tp->i2c_wbuf[tp->i2c_wlen -
tp->i2c_w_resid--]);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR_RD: write data %x\n",
tp->i2c_wbuf[tp->i2c_wlen -
(tp->i2c_w_resid + 1)]));
} else {
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_put_s1(i2c, S1_START2);
else
pcf8584_put_s1(i2c, S1_START2 | S1_ENI);
pcf8584_put_s0(i2c, addr | I2C_READ);
i2c->pcf8584_tran_state =
TRAN_STATE_DUMMY_RD;
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"TRAN_STATE_WR_RD: write addr "
"%x\n", addr | I2C_READ));
}
return (I2C_PENDING);
default:
return (I2C_COMPLETE);
}
}
/*
* pcf8584_transfer() is the function that is registered with
* I2C services to be called from pcf8584_transfer() for each transfer.
*
* This function starts the transfer, and then waits for the
* interrupt or polled thread to signal that the transfer has
* completed.
*/
int
pcf8584_transfer(dev_info_t *dip, i2c_transfer_t *tp)
{
pcf8584_t *i2c;
int saved_mode, took_over = 0;
kcondvar_t *waiter = NULL;
extern int do_polled_io;
i2c = (pcf8584_t *)ddi_get_soft_state(pcf8584_state,
ddi_get_instance(ddi_get_parent(dip)));
tp->i2c_r_resid = tp->i2c_rlen;
tp->i2c_w_resid = tp->i2c_wlen;
tp->i2c_result = I2C_SUCCESS;
begin:
/*
* If we're explicitly asked to do polled io (or if we are panic'ing),
* we need to usurp ownership of the I2C bus, bypassing any other
* waiters.
*/
if (do_polled_io || ddi_in_panic()) {
pcf8584_take_over(i2c, dip, tp, &waiter, &saved_mode);
took_over = 1;
} else {
pcf8584_acquire(i2c, dip, tp, B_FALSE);
mutex_enter(&i2c->pcf8584_imutex);
/*
* See if someone else had intruded and taken over the bus
* between the 'pcf8584_acquire' and 'mutex_enter' above.
* If so, we'll have to start all over again.
*/
if (i2c->pcf8584_cur_tran != tp) {
mutex_exit(&i2c->pcf8584_imutex);
goto begin;
}
}
if (pcf8584_bbn_ready(i2c) != I2C_SUCCESS) {
if (took_over)
pcf8584_give_up(i2c, waiter, saved_mode);
else {
mutex_exit(&i2c->pcf8584_imutex);
pcf8584_release(i2c, B_FALSE);
}
return (tp->i2c_result = I2C_FAILURE);
}
/*
* Bus selection must be followed by pcf8584_bbn_ready(),
* otherwise the bus can be switched before the stop
* bit is written out, causing the stop bit to get
* sent to the wrong (new) bus. This causes the
* previous bus to permanently hang waiting for the
* stop bit.
*/
pcf8584_select_bus(i2c);
i2c->pcf8584_tran_state = TRAN_STATE_DUMMY_DATA;
pcf8584_put_s0(i2c, DUMMY_ADDR);
PCF8584_DDB(pcf8584_print(PRT_TRAN,
"FIRST WRITE DUMMY ADDR: write %x\n", DUMMY_ADDR));
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_put_s1(i2c, S1_START);
else
pcf8584_put_s1(i2c, S1_START | S1_ENI);
/*
* Update transfer status so any polled i/o request coming in
* after this will complete this transfer for us, before issuing
* its own.
*/
i2c->pcf8584_cur_status = PCF8584_TRANSFER_ON;
if (i2c->pcf8584_mode == PCF8584_POLL_MODE)
pcf8584_do_polled_io(i2c);
if (took_over)
pcf8584_give_up(i2c, waiter, saved_mode);
else {
if (i2c->pcf8584_mode != PCF8584_POLL_MODE)
cv_wait(&i2c->pcf8584_icv, &i2c->pcf8584_imutex);
mutex_exit(&i2c->pcf8584_imutex);
/*
* Release the I2C bus only if we still own it. If we don't
* own it (someone usurped it from us while we were waiting),
* we still need to drop the lock that serializes access to
* the pcf8584 controller on systems where OBP shares the
* controller with the OS.
*/
if (i2c->pcf8584_cur_tran == tp)
pcf8584_release(i2c, B_FALSE);
else if (&plat_shared_i2c_exit && dip)
plat_shared_i2c_exit(i2c->pcf8584_dip);
}
return (tp->i2c_result);
}
static void
pcf8584_do_polled_io(pcf8584_t *i2c)
{
int completed = I2C_PENDING;
uint8_t s1;
while (completed != I2C_COMPLETE) {
s1 = pcf8584_get_s1(i2c);
if (!(s1 & S1_PIN)) {
ASSERT(i2c->pcf8584_cur_tran);
completed = pcf8584_process(i2c, s1);
}
drv_usecwait(1);
}
i2c->pcf8584_cur_status = PCF8584_TRANSFER_OVER;
}
/*
* pcf8584_take_over() grabs the I2C bus and other resources by force and
* flushes any pending transaction. This is called if a polled i/o
* request comes in.
*/
static void
pcf8584_take_over(pcf8584_t *i2c, dev_info_t *dip, i2c_transfer_t *tp,
kcondvar_t **waiter, int *saved_mode)
{
mutex_enter(&i2c->pcf8584_imutex);
*saved_mode = i2c->pcf8584_mode;
i2c->pcf8584_mode = PCF8584_POLL_MODE;
/*
* We need to flush out any currently pending transaction before
* issuing ours.
*/
if (i2c->pcf8584_busy) {
if (i2c->pcf8584_cur_tran &&
i2c->pcf8584_cur_status == PCF8584_TRANSFER_ON) {
pcf8584_do_polled_io(i2c);
*waiter = &i2c->pcf8584_icv;
}
}
/*
* Since pcf8584_acquire() is by default a good citizen that
* will wait its turn to acquire the I2C bus, we need to set
* the 'force' flag on.
*/
pcf8584_acquire(i2c, dip, tp, B_TRUE);
}
/*
* pcf8584_give_up() returns all resources that were taken over forcefully
*/
static void
pcf8584_give_up(pcf8584_t *i2c, kcondvar_t *waiter, int saved_mode)
{
i2c->pcf8584_mode = saved_mode;
/*
* Note that pcf8584_release only wakes up threads waiting to acquire
* the I2C bus. We still need to wake up the waiter from whom we
* usurped the bus.
*/
pcf8584_release(i2c, B_TRUE);
if (waiter)
cv_signal(waiter);
mutex_exit(&i2c->pcf8584_imutex);
}