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freebsd-src/sys/dev/ichiic/ig4_iic.c
Ahmad Khalifa 493715f9b8 ig4_iic: Warn on NACK 
Some DSDTs define non-existent devices, warn the user when an access is attempted on one of these devices.

Reviewed by: imp, markj, Elliott Mitchell
Pull Request: https://github.com/freebsd/freebsd-src/pull/1125
2024-04-19 16:44:57 -06:00

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/*
* 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>
/*
* Intel fourth generation mobile cpus integrated I2C device.
*
* See ig4_reg.h for datasheet reference and notes.
* See ig4_var.h for locking semantics.
*/
#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/errno.h>
#include <sys/kdb.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sx.h>
#include <sys/syslog.h>
#include <sys/bus.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <sys/rman.h>
#ifdef DEV_ACPI
#include <contrib/dev/acpica/include/acpi.h>
#include <contrib/dev/acpica/include/accommon.h>
#include <dev/acpica/acpivar.h>
#endif
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/ichiic/ig4_reg.h>
#include <dev/ichiic/ig4_var.h>
#define DO_POLL(sc) (cold || kdb_active || SCHEDULER_STOPPED() || sc->poll)
/*
* tLOW, tHIGH periods of the SCL clock and maximal falling time of both
* lines are taken from I2C specifications.
*/
#define IG4_SPEED_STD_THIGH 4000 /* nsec */
#define IG4_SPEED_STD_TLOW 4700 /* nsec */
#define IG4_SPEED_STD_TF_MAX 300 /* nsec */
#define IG4_SPEED_FAST_THIGH 600 /* nsec */
#define IG4_SPEED_FAST_TLOW 1300 /* nsec */
#define IG4_SPEED_FAST_TF_MAX 300 /* nsec */
/*
* Ig4 hardware parameters except Haswell are taken from intel_lpss driver
*/
static const struct ig4_hw ig4iic_hw[] = {
[IG4_EMAG] = {
.ic_clock_rate = 100, /* MHz */
},
[IG4_HASWELL] = {
.ic_clock_rate = 100, /* MHz */
.sda_hold_time = 90, /* nsec */
.txfifo_depth = 32,
.rxfifo_depth = 32,
},
[IG4_ATOM] = {
.ic_clock_rate = 100,
.sda_fall_time = 280,
.scl_fall_time = 240,
.sda_hold_time = 60,
.txfifo_depth = 32,
.rxfifo_depth = 32,
},
[IG4_SKYLAKE] = {
.ic_clock_rate = 120,
.sda_hold_time = 230,
},
[IG4_APL] = {
.ic_clock_rate = 133,
.sda_fall_time = 171,
.scl_fall_time = 208,
.sda_hold_time = 207,
},
[IG4_CANNONLAKE] = {
.ic_clock_rate = 216,
.sda_hold_time = 230,
},
[IG4_TIGERLAKE] = {
.ic_clock_rate = 133,
.sda_fall_time = 171,
.scl_fall_time = 208,
.sda_hold_time = 42,
},
[IG4_GEMINILAKE] = {
.ic_clock_rate = 133,
.sda_fall_time = 171,
.scl_fall_time = 290,
.sda_hold_time = 313,
},
};
static int ig4iic_set_config(ig4iic_softc_t *sc, bool reset);
static driver_filter_t ig4iic_intr;
static void ig4iic_dump(ig4iic_softc_t *sc);
static int ig4_dump;
SYSCTL_INT(_debug, OID_AUTO, ig4_dump, CTLFLAG_RW,
&ig4_dump, 0, "Dump controller registers");
/*
* Clock registers initialization control
* 0 - Try read clock registers from ACPI and fallback to p.1.
* 1 - Calculate values based on controller type (IC clock rate).
* 2 - Use values inherited from DragonflyBSD driver (old behavior).
* 3 - Keep clock registers intact.
*/
static int ig4_timings;
SYSCTL_INT(_debug, OID_AUTO, ig4_timings, CTLFLAG_RDTUN, &ig4_timings, 0,
"Controller timings 0=ACPI, 1=predefined, 2=legacy, 3=do not change");
/*
* Low-level inline support functions
*/
static __inline void
reg_write(ig4iic_softc_t *sc, uint32_t reg, uint32_t value)
{
bus_write_4(sc->regs_res, reg, value);
bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_WRITE);
}
static __inline uint32_t
reg_read(ig4iic_softc_t *sc, uint32_t reg)
{
uint32_t value;
bus_barrier(sc->regs_res, reg, 4, BUS_SPACE_BARRIER_READ);
value = bus_read_4(sc->regs_res, reg);
return (value);
}
static void
ig4iic_set_intr_mask(ig4iic_softc_t *sc, uint32_t val)
{
if (sc->intr_mask != val) {
reg_write(sc, IG4_REG_INTR_MASK, val);
sc->intr_mask = val;
}
}
static int
intrstat2iic(ig4iic_softc_t *sc, uint32_t val)
{
uint32_t src;
if (val & IG4_INTR_RX_UNDER)
reg_read(sc, IG4_REG_CLR_RX_UNDER);
if (val & IG4_INTR_RX_OVER)
reg_read(sc, IG4_REG_CLR_RX_OVER);
if (val & IG4_INTR_TX_OVER)
reg_read(sc, IG4_REG_CLR_TX_OVER);
if (val & IG4_INTR_TX_ABRT) {
src = reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
reg_read(sc, IG4_REG_CLR_TX_ABORT);
/* User-requested abort. Not really a error */
if (src & IG4_ABRTSRC_TRANSFER)
return (IIC_ESTATUS);
/* Master has lost arbitration */
if (src & IG4_ABRTSRC_ARBLOST)
return (IIC_EBUSBSY);
/* Did not receive an acknowledge from the remote slave */
if (src & (IG4_ABRTSRC_TXNOACK_ADDR7 |
IG4_ABRTSRC_TXNOACK_ADDR10_1 |
IG4_ABRTSRC_TXNOACK_ADDR10_2 |
IG4_ABRTSRC_TXNOACK_DATA |
IG4_ABRTSRC_GENCALL_NOACK))
return (IIC_ENOACK);
/* Programming errors */
if (src & (IG4_ABRTSRC_GENCALL_READ |
IG4_ABRTSRC_NORESTART_START |
IG4_ABRTSRC_NORESTART_10))
return (IIC_ENOTSUPP);
/* Other errors */
if (src & IG4_ABRTSRC_ACKED_START)
return (IIC_EBUSERR);
}
/*
* TX_OVER, RX_OVER and RX_UNDER are caused by wrong RX/TX FIFO depth
* detection or driver's read/write pipelining errors.
*/
if (val & (IG4_INTR_TX_OVER | IG4_INTR_RX_OVER))
return (IIC_EOVERFLOW);
if (val & IG4_INTR_RX_UNDER)
return (IIC_EUNDERFLOW);
return (IIC_NOERR);
}
/*
* Enable or disable the controller and wait for the controller to acknowledge
* the state change.
*/
static int
set_controller(ig4iic_softc_t *sc, uint32_t ctl)
{
int retry;
int error;
uint32_t v;
/*
* When the controller is enabled, interrupt on STOP detect
* or receive character ready and clear pending interrupts.
*/
ig4iic_set_intr_mask(sc, 0);
if (ctl & IG4_I2C_ENABLE)
reg_read(sc, IG4_REG_CLR_INTR);
reg_write(sc, IG4_REG_I2C_EN, ctl);
error = IIC_ETIMEOUT;
for (retry = 100; retry > 0; --retry) {
v = reg_read(sc, IG4_REG_ENABLE_STATUS);
if (((v ^ ctl) & IG4_I2C_ENABLE) == 0) {
error = 0;
break;
}
pause("i2cslv", 1);
}
return (error);
}
/*
* Wait up to 25ms for the requested interrupt using a 25uS polling loop.
*/
static int
wait_intr(ig4iic_softc_t *sc, uint32_t intr)
{
uint32_t v;
int error;
int txlvl = -1;
u_int count_us = 0;
u_int limit_us = 1000000; /* 1sec */
for (;;) {
/*
* Check requested status
*/
v = reg_read(sc, IG4_REG_RAW_INTR_STAT);
error = intrstat2iic(sc, v & IG4_INTR_ERR_MASK);
if (error || (v & intr))
break;
/*
* When waiting for the transmit FIFO to become empty,
* reset the timeout if we see a change in the transmit
* FIFO level as progress is being made.
*/
if (intr & (IG4_INTR_TX_EMPTY | IG4_INTR_STOP_DET)) {
v = reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK;
if (txlvl != v) {
txlvl = v;
count_us = 0;
}
}
/*
* Stop if we've run out of time.
*/
if (count_us >= limit_us) {
error = IIC_ETIMEOUT;
break;
}
/*
* When polling is not requested let the interrupt do its work.
*/
if (!DO_POLL(sc)) {
mtx_lock_spin(&sc->io_lock);
ig4iic_set_intr_mask(sc, intr | IG4_INTR_ERR_MASK);
msleep_spin(sc, &sc->io_lock, "i2cwait",
(hz + 99) / 100); /* sleep up to 10ms */
ig4iic_set_intr_mask(sc, 0);
mtx_unlock_spin(&sc->io_lock);
count_us += 10000;
} else {
DELAY(25);
count_us += 25;
}
}
return (error);
}
/*
* Set the slave address. The controller must be disabled when
* changing the address.
*
* This operation does not issue anything to the I2C bus but sets
* the target address for when the controller later issues a START.
*/
static void
set_slave_addr(ig4iic_softc_t *sc, uint8_t slave)
{
uint32_t tar;
uint32_t ctl;
bool use_10bit;
use_10bit = false;
if (sc->slave_valid && sc->last_slave == slave &&
sc->use_10bit == use_10bit) {
return;
}
sc->use_10bit = use_10bit;
/*
* Wait for TXFIFO to drain before disabling the controller.
*/
reg_write(sc, IG4_REG_TX_TL, 0);
wait_intr(sc, IG4_INTR_TX_EMPTY);
set_controller(sc, 0);
ctl = reg_read(sc, IG4_REG_CTL);
ctl &= ~IG4_CTL_10BIT;
ctl |= IG4_CTL_RESTARTEN;
tar = slave;
if (sc->use_10bit) {
tar |= IG4_TAR_10BIT;
ctl |= IG4_CTL_10BIT;
}
reg_write(sc, IG4_REG_CTL, ctl);
reg_write(sc, IG4_REG_TAR_ADD, tar);
set_controller(sc, IG4_I2C_ENABLE);
sc->slave_valid = true;
sc->last_slave = slave;
}
/*
* IICBUS API FUNCTIONS
*/
static int
ig4iic_xfer_start(ig4iic_softc_t *sc, uint16_t slave, bool repeated_start)
{
set_slave_addr(sc, slave >> 1);
if (!repeated_start) {
/*
* Clear any previous TX/RX FIFOs overflow/underflow bits
* and I2C bus STOP condition.
*/
reg_read(sc, IG4_REG_CLR_INTR);
}
return (0);
}
static bool
ig4iic_xfer_is_started(ig4iic_softc_t *sc)
{
/*
* It requires that no IG4_REG_CLR_INTR or IG4_REG_CLR_START/STOP_DET
* register reads is issued after START condition.
*/
return ((reg_read(sc, IG4_REG_RAW_INTR_STAT) &
(IG4_INTR_START_DET | IG4_INTR_STOP_DET)) == IG4_INTR_START_DET);
}
static int
ig4iic_xfer_abort(ig4iic_softc_t *sc)
{
int error;
/* Request send of STOP condition and flush of TX FIFO */
set_controller(sc, IG4_I2C_ABORT | IG4_I2C_ENABLE);
/*
* Wait for the TX_ABRT interrupt with ABRTSRC_TRANSFER
* bit set in TX_ABRT_SOURCE register.
*/
error = wait_intr(sc, IG4_INTR_STOP_DET);
set_controller(sc, IG4_I2C_ENABLE);
return (error == IIC_ESTATUS ? 0 : error);
}
/*
* Amount of unread data before next burst to get better I2C bus utilization.
* 2 bytes is enough in FAST mode. 8 bytes is better in FAST+ and HIGH modes.
* Intel-recommended value is 16 for DMA transfers with 64-byte depth FIFOs.
*/
#define IG4_FIFO_LOWAT 2
static int
ig4iic_read(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
bool repeated_start, bool stop)
{
uint32_t cmd;
int requested = 0;
int received = 0;
int burst, target, lowat = 0;
int error;
if (len == 0)
return (0);
while (received < len) {
/* Ensure we have some free space in TXFIFO */
burst = sc->cfg.txfifo_depth -
(reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
if (burst <= 0) {
reg_write(sc, IG4_REG_TX_TL, IG4_FIFO_LOWAT);
error = wait_intr(sc, IG4_INTR_TX_EMPTY);
if (error)
break;
burst = sc->cfg.txfifo_depth -
(reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
}
/* Ensure we have enough free space in RXFIFO */
burst = MIN(burst, sc->cfg.rxfifo_depth -
(requested - received));
target = MIN(requested + burst, (int)len);
while (requested < target) {
cmd = IG4_DATA_COMMAND_RD;
if (repeated_start && requested == 0)
cmd |= IG4_DATA_RESTART;
if (stop && requested == len - 1)
cmd |= IG4_DATA_STOP;
reg_write(sc, IG4_REG_DATA_CMD, cmd);
requested++;
}
/* Leave some data queued to maintain the hardware pipeline */
lowat = 0;
if (requested != len && requested - received > IG4_FIFO_LOWAT)
lowat = IG4_FIFO_LOWAT;
/* After TXFLR fills up, clear it by reading available data */
while (received < requested - lowat) {
burst = MIN(requested - received,
reg_read(sc, IG4_REG_RXFLR) & IG4_FIFOLVL_MASK);
if (burst > 0) {
while (burst--)
buf[received++] = 0xFF &
reg_read(sc, IG4_REG_DATA_CMD);
} else {
reg_write(sc, IG4_REG_RX_TL,
requested - received - lowat - 1);
error = wait_intr(sc, IG4_INTR_RX_FULL);
if (error)
goto out;
}
}
}
out:
return (error);
}
static int
ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
bool repeated_start, bool stop)
{
uint32_t cmd;
int sent = 0;
int burst, target;
int error, lowat;
if (len == 0)
return (0);
while (sent < len) {
burst = sc->cfg.txfifo_depth -
(reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
target = MIN(sent + burst, (int)len);
while (sent < target) {
cmd = buf[sent];
if (repeated_start && sent == 0)
cmd |= IG4_DATA_RESTART;
if (stop && sent == len - 1)
cmd |= IG4_DATA_STOP;
reg_write(sc, IG4_REG_DATA_CMD, cmd);
sent++;
}
if (sent < len) {
if (len - sent <= sc->cfg.txfifo_depth)
lowat = sc->cfg.txfifo_depth - (len - sent);
else
lowat = IG4_FIFO_LOWAT;
reg_write(sc, IG4_REG_TX_TL, lowat);
error = wait_intr(sc, IG4_INTR_TX_EMPTY);
if (error)
break;
}
}
return (error);
}
int
ig4iic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
ig4iic_softc_t *sc = device_get_softc(dev);
const char *reason = NULL;
uint32_t i;
int error;
int unit;
bool rpstart;
bool stop;
bool allocated;
/*
* The hardware interface imposes limits on allowed I2C messages.
* It is not possible to explicitly send a start or stop.
* They are automatically sent (or not sent, depending on the
* configuration) when a data byte is transferred.
* For this reason it's impossible to send a message with no data
* at all (like an SMBus quick message).
* The start condition is automatically generated after the stop
* condition, so it's impossible to not have a start after a stop.
* The repeated start condition is automatically sent if a change
* of the transfer direction happens, so it's impossible to have
* a change of direction without a (repeated) start.
* The repeated start can be forced even without the change of
* direction.
* Changing the target slave address requires resetting the hardware
* state, so it's impossible to do that without the stop followed
* by the start.
*/
for (i = 0; i < nmsgs; i++) {
#if 0
if (i == 0 && (msgs[i].flags & IIC_M_NOSTART) != 0) {
reason = "first message without start";
break;
}
if (i == nmsgs - 1 && (msgs[i].flags & IIC_M_NOSTOP) != 0) {
reason = "last message without stop";
break;
}
#endif
if (msgs[i].len == 0) {
reason = "message with no data";
break;
}
if (i > 0) {
if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
(msgs[i - 1].flags & IIC_M_NOSTOP) == 0) {
reason = "stop not followed by start";
break;
}
if ((msgs[i - 1].flags & IIC_M_NOSTOP) != 0 &&
msgs[i].slave != msgs[i - 1].slave) {
reason = "change of slave without stop";
break;
}
if ((msgs[i].flags & IIC_M_NOSTART) != 0 &&
(msgs[i].flags & IIC_M_RD) !=
(msgs[i - 1].flags & IIC_M_RD)) {
reason = "change of direction without repeated"
" start";
break;
}
}
}
if (reason != NULL) {
if (bootverbose)
device_printf(dev, "%s\n", reason);
return (IIC_ENOTSUPP);
}
/* Check if device is already allocated with iicbus_request_bus() */
allocated = sx_xlocked(&sc->call_lock) != 0;
if (!allocated)
sx_xlock(&sc->call_lock);
/* Debugging - dump registers. */
if (ig4_dump) {
unit = device_get_unit(dev);
if (ig4_dump & (1 << unit)) {
ig4_dump &= ~(1 << unit);
ig4iic_dump(sc);
}
}
/*
* Clear any previous abort condition that may have been holding
* the txfifo in reset.
*/
reg_read(sc, IG4_REG_CLR_TX_ABORT);
rpstart = false;
error = 0;
for (i = 0; i < nmsgs; i++) {
if ((msgs[i].flags & IIC_M_NOSTART) == 0) {
error = ig4iic_xfer_start(sc, msgs[i].slave, rpstart);
} else {
if (!sc->slave_valid ||
(msgs[i].slave >> 1) != sc->last_slave) {
device_printf(dev, "start condition suppressed"
"but slave address is not set up");
error = EINVAL;
break;
}
rpstart = false;
}
if (error != 0)
break;
stop = (msgs[i].flags & IIC_M_NOSTOP) == 0;
if (msgs[i].flags & IIC_M_RD)
error = ig4iic_read(sc, msgs[i].buf, msgs[i].len,
rpstart, stop);
else
error = ig4iic_write(sc, msgs[i].buf, msgs[i].len,
rpstart, stop);
/* Wait for error or stop condition occurred on the I2C bus */
if (stop && error == 0) {
error = wait_intr(sc, IG4_INTR_STOP_DET);
if (error == 0)
reg_read(sc, IG4_REG_CLR_INTR);
}
if (error != 0) {
/*
* Send STOP condition if it's not done yet and flush
* both FIFOs. Do a controller soft reset if transfer
* abort is failed.
*/
if (ig4iic_xfer_is_started(sc) &&
ig4iic_xfer_abort(sc) != 0) {
device_printf(sc->dev, "Failed to abort "
"transfer. Do the controller reset.\n");
ig4iic_set_config(sc, true);
} else {
while (reg_read(sc, IG4_REG_I2C_STA) &
IG4_STATUS_RX_NOTEMPTY)
reg_read(sc, IG4_REG_DATA_CMD);
reg_read(sc, IG4_REG_TX_ABRT_SOURCE);
reg_read(sc, IG4_REG_CLR_INTR);
}
break;
}
rpstart = !stop;
}
if (error == IIC_ENOACK && bootverbose)
device_printf(dev, "Warning: NACK for slave address 0x%x\n",
msgs[i].slave >> 1);
if (!allocated)
sx_unlock(&sc->call_lock);
return (error);
}
int
ig4iic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
ig4iic_softc_t *sc = device_get_softc(dev);
bool allocated;
allocated = sx_xlocked(&sc->call_lock) != 0;
if (!allocated)
sx_xlock(&sc->call_lock);
/* TODO handle speed configuration? */
if (oldaddr != NULL)
*oldaddr = sc->last_slave << 1;
set_slave_addr(sc, addr >> 1);
if (addr == IIC_UNKNOWN)
sc->slave_valid = false;
if (!allocated)
sx_unlock(&sc->call_lock);
return (0);
}
int
ig4iic_callback(device_t dev, int index, caddr_t data)
{
ig4iic_softc_t *sc = device_get_softc(dev);
int error = 0;
int how;
switch (index) {
case IIC_REQUEST_BUS:
/* force polling if ig4iic is requested with IIC_DONTWAIT */
how = *(int *)data;
if ((how & IIC_WAIT) == 0) {
if (sx_try_xlock(&sc->call_lock) == 0)
error = IIC_EBUSBSY;
else
sc->poll = true;
} else
sx_xlock(&sc->call_lock);
break;
case IIC_RELEASE_BUS:
sc->poll = false;
sx_unlock(&sc->call_lock);
break;
default:
error = errno2iic(EINVAL);
}
return (error);
}
/*
* Clock register values can be calculated with following rough equations:
* SCL_HCNT = ceil(IC clock rate * tHIGH)
* SCL_LCNT = ceil(IC clock rate * tLOW)
* SDA_HOLD = ceil(IC clock rate * SDA hold time)
* Precise equations take signal's falling, rising and spike suppression
* times in to account. They can be found in Synopsys or Intel documentation.
*
* Here we snarf formulas and defaults from Linux driver to be able to use
* timing values provided by Intel LPSS driver "as is".
*/
static int
ig4iic_clk_params(const struct ig4_hw *hw, int speed,
uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
{
uint32_t thigh, tlow, tf_max; /* nsec */
uint32_t sda_fall_time; /* nsec */
uint32_t scl_fall_time; /* nsec */
switch (speed) {
case IG4_CTL_SPEED_STD:
thigh = IG4_SPEED_STD_THIGH;
tlow = IG4_SPEED_STD_TLOW;
tf_max = IG4_SPEED_STD_TF_MAX;
break;
case IG4_CTL_SPEED_FAST:
thigh = IG4_SPEED_FAST_THIGH;
tlow = IG4_SPEED_FAST_TLOW;
tf_max = IG4_SPEED_FAST_TF_MAX;
break;
default:
return (EINVAL);
}
/* Use slowest falling time defaults to be on the safe side */
sda_fall_time = hw->sda_fall_time == 0 ? tf_max : hw->sda_fall_time;
*scl_hcnt = (uint16_t)
((hw->ic_clock_rate * (thigh + sda_fall_time) + 500) / 1000 - 3);
scl_fall_time = hw->scl_fall_time == 0 ? tf_max : hw->scl_fall_time;
*scl_lcnt = (uint16_t)
((hw->ic_clock_rate * (tlow + scl_fall_time) + 500) / 1000 - 1);
/*
* There is no "known good" default value for tHD;DAT so keep SDA_HOLD
* intact if sda_hold_time value is not provided.
*/
if (hw->sda_hold_time != 0)
*sda_hold = (uint16_t)
((hw->ic_clock_rate * hw->sda_hold_time + 500) / 1000);
return (0);
}
#ifdef DEV_ACPI
static ACPI_STATUS
ig4iic_acpi_params(ACPI_HANDLE handle, char *method,
uint16_t *scl_hcnt, uint16_t *scl_lcnt, uint16_t *sda_hold)
{
ACPI_BUFFER buf;
ACPI_OBJECT *obj, *elems;
ACPI_STATUS status;
buf.Pointer = NULL;
buf.Length = ACPI_ALLOCATE_BUFFER;
status = AcpiEvaluateObject(handle, method, NULL, &buf);
if (ACPI_FAILURE(status))
return (status);
status = AE_TYPE;
obj = (ACPI_OBJECT *)buf.Pointer;
if (obj->Type == ACPI_TYPE_PACKAGE && obj->Package.Count == 3) {
elems = obj->Package.Elements;
*scl_hcnt = elems[0].Integer.Value & IG4_SCL_CLOCK_MASK;
*scl_lcnt = elems[1].Integer.Value & IG4_SCL_CLOCK_MASK;
*sda_hold = elems[2].Integer.Value & IG4_SDA_TX_HOLD_MASK;
status = AE_OK;
}
AcpiOsFree(obj);
return (status);
}
#endif /* DEV_ACPI */
static void
ig4iic_get_config(ig4iic_softc_t *sc)
{
const struct ig4_hw *hw;
uint32_t v;
#ifdef DEV_ACPI
ACPI_HANDLE handle;
#endif
/* Fetch default hardware config from controller */
sc->cfg.version = reg_read(sc, IG4_REG_COMP_VER);
sc->cfg.bus_speed = reg_read(sc, IG4_REG_CTL) & IG4_CTL_SPEED_MASK;
sc->cfg.ss_scl_hcnt =
reg_read(sc, IG4_REG_SS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
sc->cfg.ss_scl_lcnt =
reg_read(sc, IG4_REG_SS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
sc->cfg.fs_scl_hcnt =
reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;
sc->cfg.fs_scl_lcnt =
reg_read(sc, IG4_REG_FS_SCL_LCNT) & IG4_SCL_CLOCK_MASK;
sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold =
reg_read(sc, IG4_REG_SDA_HOLD) & IG4_SDA_TX_HOLD_MASK;
if (sc->cfg.bus_speed != IG4_CTL_SPEED_STD)
sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
/* REG_COMP_PARAM1 is not documented in latest Intel specs */
if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
v = reg_read(sc, IG4_REG_COMP_PARAM1);
if (IG4_PARAM1_TXFIFO_DEPTH(v) != 0)
sc->cfg.txfifo_depth = IG4_PARAM1_TXFIFO_DEPTH(v);
if (IG4_PARAM1_RXFIFO_DEPTH(v) != 0)
sc->cfg.rxfifo_depth = IG4_PARAM1_RXFIFO_DEPTH(v);
}
/* Override hardware config with IC_clock-based counter values */
if (ig4_timings < 2 && sc->version < nitems(ig4iic_hw)) {
hw = &ig4iic_hw[sc->version];
sc->cfg.bus_speed = IG4_CTL_SPEED_FAST;
ig4iic_clk_params(hw, IG4_CTL_SPEED_STD, &sc->cfg.ss_scl_hcnt,
&sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
ig4iic_clk_params(hw, IG4_CTL_SPEED_FAST, &sc->cfg.fs_scl_hcnt,
&sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
if (hw->txfifo_depth != 0)
sc->cfg.txfifo_depth = hw->txfifo_depth;
if (hw->rxfifo_depth != 0)
sc->cfg.rxfifo_depth = hw->rxfifo_depth;
} else if (ig4_timings == 2) {
/*
* Timings of original ig4 driver:
* Program based on a 25000 Hz clock. This is a bit of a
* hack (obviously). The defaults are 400 and 470 for standard
* and 60 and 130 for fast. The defaults for standard fail
* utterly (presumably cause an abort) because the clock time
* is ~18.8ms by default. This brings it down to ~4ms.
*/
sc->cfg.bus_speed = IG4_CTL_SPEED_STD;
sc->cfg.ss_scl_hcnt = sc->cfg.fs_scl_hcnt = 100;
sc->cfg.ss_scl_lcnt = sc->cfg.fs_scl_lcnt = 125;
if (sc->version == IG4_SKYLAKE)
sc->cfg.ss_sda_hold = sc->cfg.fs_sda_hold = 28;
}
#ifdef DEV_ACPI
/* Evaluate SSCN and FMCN ACPI methods to fetch timings */
if (ig4_timings == 0 && (handle = acpi_get_handle(sc->dev)) != NULL) {
ig4iic_acpi_params(handle, "SSCN", &sc->cfg.ss_scl_hcnt,
&sc->cfg.ss_scl_lcnt, &sc->cfg.ss_sda_hold);
ig4iic_acpi_params(handle, "FMCN", &sc->cfg.fs_scl_hcnt,
&sc->cfg.fs_scl_lcnt, &sc->cfg.fs_sda_hold);
}
#endif
if (bootverbose) {
device_printf(sc->dev, "Controller parameters:\n");
printf(" Speed: %s\n",
sc->cfg.bus_speed == IG4_CTL_SPEED_STD ? "Std" : "Fast");
printf(" Regs: HCNT :LCNT :SDAHLD\n");
printf(" Std: 0x%04hx:0x%04hx:0x%04hx\n",
sc->cfg.ss_scl_hcnt, sc->cfg.ss_scl_lcnt,
sc->cfg.ss_sda_hold);
printf(" Fast: 0x%04hx:0x%04hx:0x%04hx\n",
sc->cfg.fs_scl_hcnt, sc->cfg.fs_scl_lcnt,
sc->cfg.fs_sda_hold);
}
}
static int
ig4iic_set_config(ig4iic_softc_t *sc, bool reset)
{
uint32_t v;
v = reg_read(sc, IG4_REG_DEVIDLE_CTRL);
if (IG4_HAS_ADDREGS(sc->version) && (v & IG4_RESTORE_REQUIRED)) {
reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE | IG4_RESTORE_REQUIRED);
reg_write(sc, IG4_REG_DEVIDLE_CTRL, 0);
pause("i2crst", 1);
reset = true;
}
if ((sc->version == IG4_HASWELL || sc->version == IG4_ATOM) && reset) {
reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_ASSERT_HSW);
reg_write(sc, IG4_REG_RESETS_HSW, IG4_RESETS_DEASSERT_HSW);
} else if (IG4_HAS_ADDREGS(sc->version) && reset) {
reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_DEASSERT_SKL);
}
if (sc->version == IG4_ATOM)
v = reg_read(sc, IG4_REG_COMP_TYPE);
if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
v = reg_read(sc, IG4_REG_COMP_PARAM1);
v = reg_read(sc, IG4_REG_GENERAL);
/*
* The content of IG4_REG_GENERAL is different for each
* controller version.
*/
if (sc->version == IG4_HASWELL &&
(v & IG4_GENERAL_SWMODE) == 0) {
v |= IG4_GENERAL_SWMODE;
reg_write(sc, IG4_REG_GENERAL, v);
v = reg_read(sc, IG4_REG_GENERAL);
}
}
if (sc->version == IG4_HASWELL) {
v = reg_read(sc, IG4_REG_SW_LTR_VALUE);
v = reg_read(sc, IG4_REG_AUTO_LTR_VALUE);
} else if (IG4_HAS_ADDREGS(sc->version)) {
v = reg_read(sc, IG4_REG_ACTIVE_LTR_VALUE);
v = reg_read(sc, IG4_REG_IDLE_LTR_VALUE);
}
if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
v = reg_read(sc, IG4_REG_COMP_VER);
if (v < IG4_COMP_MIN_VER)
return(ENXIO);
}
if (set_controller(sc, 0)) {
device_printf(sc->dev, "controller error during attach-1\n");
return (ENXIO);
}
reg_read(sc, IG4_REG_CLR_INTR);
reg_write(sc, IG4_REG_INTR_MASK, 0);
sc->intr_mask = 0;
reg_write(sc, IG4_REG_SS_SCL_HCNT, sc->cfg.ss_scl_hcnt);
reg_write(sc, IG4_REG_SS_SCL_LCNT, sc->cfg.ss_scl_lcnt);
reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
reg_write(sc, IG4_REG_FS_SCL_LCNT, sc->cfg.fs_scl_lcnt);
reg_write(sc, IG4_REG_SDA_HOLD,
(sc->cfg.bus_speed & IG4_CTL_SPEED_MASK) == IG4_CTL_SPEED_STD ?
sc->cfg.ss_sda_hold : sc->cfg.fs_sda_hold);
reg_write(sc, IG4_REG_RX_TL, 0);
reg_write(sc, IG4_REG_TX_TL, 0);
reg_write(sc, IG4_REG_CTL,
IG4_CTL_MASTER |
IG4_CTL_SLAVE_DISABLE |
IG4_CTL_RESTARTEN |
(sc->cfg.bus_speed & IG4_CTL_SPEED_MASK));
/* Force setting of the target address on the next transfer */
sc->slave_valid = false;
return (0);
}
static void
ig4iic_get_fifo(ig4iic_softc_t *sc)
{
uint32_t v;
/*
* Hardware does not allow FIFO Threshold Levels value to be set larger
* than the depth of the buffer. If an attempt is made to do that, the
* actual value set will be the maximum depth of the buffer.
*/
if (sc->cfg.txfifo_depth == 0) {
v = reg_read(sc, IG4_REG_TX_TL);
reg_write(sc, IG4_REG_TX_TL, v | IG4_FIFO_MASK);
sc->cfg.txfifo_depth =
(reg_read(sc, IG4_REG_TX_TL) & IG4_FIFO_MASK) + 1;
reg_write(sc, IG4_REG_TX_TL, v);
}
if (sc->cfg.rxfifo_depth == 0) {
v = reg_read(sc, IG4_REG_RX_TL);
reg_write(sc, IG4_REG_RX_TL, v | IG4_FIFO_MASK);
sc->cfg.rxfifo_depth =
(reg_read(sc, IG4_REG_RX_TL) & IG4_FIFO_MASK) + 1;
reg_write(sc, IG4_REG_RX_TL, v);
}
if (bootverbose) {
printf(" FIFO: RX:0x%04x: TX:0x%04x\n",
sc->cfg.rxfifo_depth, sc->cfg.txfifo_depth);
}
}
/*
* Called from ig4iic_pci_attach/detach()
*/
int
ig4iic_attach(ig4iic_softc_t *sc)
{
int error;
mtx_init(&sc->io_lock, "IG4 I/O lock", NULL, MTX_SPIN);
sx_init(&sc->call_lock, "IG4 call lock");
ig4iic_get_config(sc);
error = ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version));
if (error)
goto done;
ig4iic_get_fifo(sc);
sc->iicbus = device_add_child(sc->dev, "iicbus", -1);
if (sc->iicbus == NULL) {
device_printf(sc->dev, "iicbus driver not found\n");
error = ENXIO;
goto done;
}
if (set_controller(sc, IG4_I2C_ENABLE)) {
device_printf(sc->dev, "controller error during attach-2\n");
error = ENXIO;
goto done;
}
if (set_controller(sc, 0)) {
device_printf(sc->dev, "controller error during attach-3\n");
error = ENXIO;
goto done;
}
error = bus_setup_intr(sc->dev, sc->intr_res, INTR_TYPE_MISC | INTR_MPSAFE,
ig4iic_intr, NULL, sc, &sc->intr_handle);
if (error) {
device_printf(sc->dev,
"Unable to setup irq: error %d\n", error);
}
error = bus_generic_attach(sc->dev);
if (error) {
device_printf(sc->dev,
"failed to attach child: error %d\n", error);
}
done:
return (error);
}
int
ig4iic_detach(ig4iic_softc_t *sc)
{
int error;
if (device_is_attached(sc->dev)) {
error = bus_generic_detach(sc->dev);
if (error)
return (error);
}
if (sc->iicbus)
device_delete_child(sc->dev, sc->iicbus);
if (sc->intr_handle)
bus_teardown_intr(sc->dev, sc->intr_res, sc->intr_handle);
sx_xlock(&sc->call_lock);
sc->iicbus = NULL;
sc->intr_handle = NULL;
reg_write(sc, IG4_REG_INTR_MASK, 0);
set_controller(sc, 0);
sx_xunlock(&sc->call_lock);
mtx_destroy(&sc->io_lock);
sx_destroy(&sc->call_lock);
return (0);
}
int
ig4iic_suspend(ig4iic_softc_t *sc)
{
int error;
/* suspend all children */
error = bus_generic_suspend(sc->dev);
sx_xlock(&sc->call_lock);
set_controller(sc, 0);
if (IG4_HAS_ADDREGS(sc->version)) {
/*
* Place the device in the idle state, just to be safe
*/
reg_write(sc, IG4_REG_DEVIDLE_CTRL, IG4_DEVICE_IDLE);
/*
* Controller can become dysfunctional if I2C lines are pulled
* down when suspend procedure turns off power to I2C device.
* Place device in the reset state to avoid this.
*/
reg_write(sc, IG4_REG_RESETS_SKL, IG4_RESETS_ASSERT_SKL);
}
sx_xunlock(&sc->call_lock);
return (error);
}
int ig4iic_resume(ig4iic_softc_t *sc)
{
int error;
sx_xlock(&sc->call_lock);
if (ig4iic_set_config(sc, IG4_HAS_ADDREGS(sc->version)))
device_printf(sc->dev, "controller error during resume\n");
sx_xunlock(&sc->call_lock);
error = bus_generic_resume(sc->dev);
return (error);
}
/*
* Interrupt Operation, see ig4_var.h for locking semantics.
*/
static int
ig4iic_intr(void *cookie)
{
ig4iic_softc_t *sc = cookie;
int retval = FILTER_STRAY;
mtx_lock_spin(&sc->io_lock);
/* Ignore stray interrupts */
if (sc->intr_mask != 0 && reg_read(sc, IG4_REG_INTR_STAT) != 0) {
/* Interrupt bits are cleared in wait_intr() loop */
ig4iic_set_intr_mask(sc, 0);
wakeup(sc);
retval = FILTER_HANDLED;
}
mtx_unlock_spin(&sc->io_lock);
return (retval);
}
#define REGDUMP(sc, reg) \
device_printf(sc->dev, " %-23s %08x\n", #reg, reg_read(sc, reg))
static void
ig4iic_dump(ig4iic_softc_t *sc)
{
device_printf(sc->dev, "ig4iic register dump:\n");
REGDUMP(sc, IG4_REG_CTL);
REGDUMP(sc, IG4_REG_TAR_ADD);
REGDUMP(sc, IG4_REG_SS_SCL_HCNT);
REGDUMP(sc, IG4_REG_SS_SCL_LCNT);
REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
REGDUMP(sc, IG4_REG_FS_SCL_LCNT);
REGDUMP(sc, IG4_REG_INTR_STAT);
REGDUMP(sc, IG4_REG_INTR_MASK);
REGDUMP(sc, IG4_REG_RAW_INTR_STAT);
REGDUMP(sc, IG4_REG_RX_TL);
REGDUMP(sc, IG4_REG_TX_TL);
REGDUMP(sc, IG4_REG_I2C_EN);
REGDUMP(sc, IG4_REG_I2C_STA);
REGDUMP(sc, IG4_REG_TXFLR);
REGDUMP(sc, IG4_REG_RXFLR);
REGDUMP(sc, IG4_REG_SDA_HOLD);
REGDUMP(sc, IG4_REG_TX_ABRT_SOURCE);
REGDUMP(sc, IG4_REG_SLV_DATA_NACK);
REGDUMP(sc, IG4_REG_DMA_CTRL);
REGDUMP(sc, IG4_REG_DMA_TDLR);
REGDUMP(sc, IG4_REG_DMA_RDLR);
REGDUMP(sc, IG4_REG_SDA_SETUP);
REGDUMP(sc, IG4_REG_ENABLE_STATUS);
REGDUMP(sc, IG4_REG_COMP_PARAM1);
REGDUMP(sc, IG4_REG_COMP_VER);
if (sc->version == IG4_ATOM) {
REGDUMP(sc, IG4_REG_COMP_TYPE);
REGDUMP(sc, IG4_REG_CLK_PARMS);
}
if (sc->version == IG4_HASWELL || sc->version == IG4_ATOM) {
REGDUMP(sc, IG4_REG_RESETS_HSW);
REGDUMP(sc, IG4_REG_GENERAL);
} else if (sc->version == IG4_SKYLAKE) {
REGDUMP(sc, IG4_REG_RESETS_SKL);
}
if (sc->version == IG4_HASWELL) {
REGDUMP(sc, IG4_REG_SW_LTR_VALUE);
REGDUMP(sc, IG4_REG_AUTO_LTR_VALUE);
} else if (IG4_HAS_ADDREGS(sc->version)) {
REGDUMP(sc, IG4_REG_ACTIVE_LTR_VALUE);
REGDUMP(sc, IG4_REG_IDLE_LTR_VALUE);
}
}
#undef REGDUMP
DRIVER_MODULE(iicbus, ig4iic, iicbus_driver, NULL, NULL);
#ifdef DEV_ACPI
DRIVER_MODULE(acpi_iicbus, ig4iic, acpi_iicbus_driver, NULL, NULL);
#endif
MODULE_DEPEND(ig4iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(ig4iic, 1);
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