freebsd-nq/sys/arm/mv/twsi.c
Ian Lepore add35ed5b8 Follow r261352 by updating all drivers which are children of simplebus
to check the status property in their probe routines.

Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352.  Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.

Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
2014-02-02 19:17:28 +00:00

642 lines
15 KiB
C

/*-
* Copyright (C) 2008 MARVELL INTERNATIONAL LTD.
* All rights reserved.
*
* Developed by Semihalf.
*
* 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 MARVELL nor the names of contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY 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 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.
*/
/*
* Driver for the TWSI (aka I2C, aka IIC) bus controller found on Marvell
* SoCs. Supports master operation only, and works in polling mode.
*
* Calls to DELAY() are needed per Application Note AN-179 "TWSI Software
* Guidelines for Discovery(TM), Horizon (TM) and Feroceon(TM) Devices".
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <machine/_inttypes.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/mv/mvreg.h>
#include <arm/mv/mvvar.h>
#include "iicbus_if.h"
#define MV_TWSI_NAME "twsi"
#define IICBUS_DEVNAME "iicbus"
#define TWSI_SLAVE_ADDR 0x00
#define TWSI_EXT_SLAVE_ADDR 0x10
#define TWSI_DATA 0x04
#define TWSI_CONTROL 0x08
#define TWSI_CONTROL_ACK (1 << 2)
#define TWSI_CONTROL_IFLG (1 << 3)
#define TWSI_CONTROL_STOP (1 << 4)
#define TWSI_CONTROL_START (1 << 5)
#define TWSI_CONTROL_TWSIEN (1 << 6)
#define TWSI_CONTROL_INTEN (1 << 7)
#define TWSI_STATUS 0x0c
#define TWSI_STATUS_START 0x08
#define TWSI_STATUS_RPTD_START 0x10
#define TWSI_STATUS_ADDR_W_ACK 0x18
#define TWSI_STATUS_DATA_WR_ACK 0x28
#define TWSI_STATUS_ADDR_R_ACK 0x40
#define TWSI_STATUS_DATA_RD_ACK 0x50
#define TWSI_STATUS_DATA_RD_NOACK 0x58
#define TWSI_BAUD_RATE 0x0c
#define TWSI_BAUD_RATE_PARAM(M,N) ((((M) << 3) | ((N) & 0x7)) & 0x7f)
#define TWSI_BAUD_RATE_RAW(C,M,N) ((C)/((10*(M+1))<<(N+1)))
#define TWSI_BAUD_RATE_SLOW 50000 /* 50kHz */
#define TWSI_BAUD_RATE_FAST 100000 /* 100kHz */
#define TWSI_SOFT_RESET 0x1c
#define TWSI_DEBUG
#undef TWSI_DEBUG
#ifdef TWSI_DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0)
#else
#define debugf(fmt, args...)
#endif
struct mv_twsi_softc {
device_t dev;
struct resource *res[1]; /* SYS_RES_MEMORY */
struct mtx mutex;
device_t iicbus;
};
static struct mv_twsi_baud_rate {
uint32_t raw;
int param;
int m;
int n;
} baud_rate[IIC_FASTEST + 1];
static int mv_twsi_probe(device_t);
static int mv_twsi_attach(device_t);
static int mv_twsi_detach(device_t);
static int mv_twsi_reset(device_t dev, u_char speed, u_char addr,
u_char *oldaddr);
static int mv_twsi_repeated_start(device_t dev, u_char slave, int timeout);
static int mv_twsi_start(device_t dev, u_char slave, int timeout);
static int mv_twsi_stop(device_t dev);
static int mv_twsi_read(device_t dev, char *buf, int len, int *read, int last,
int delay);
static int mv_twsi_write(device_t dev, const char *buf, int len, int *sent,
int timeout);
static struct resource_spec res_spec[] = {
{ SYS_RES_MEMORY, 0, RF_ACTIVE },
{ -1, 0 }
};
static device_method_t mv_twsi_methods[] = {
/* device interface */
DEVMETHOD(device_probe, mv_twsi_probe),
DEVMETHOD(device_attach, mv_twsi_attach),
DEVMETHOD(device_detach, mv_twsi_detach),
/* iicbus interface */
DEVMETHOD(iicbus_callback, iicbus_null_callback),
DEVMETHOD(iicbus_repeated_start, mv_twsi_repeated_start),
DEVMETHOD(iicbus_start, mv_twsi_start),
DEVMETHOD(iicbus_stop, mv_twsi_stop),
DEVMETHOD(iicbus_write, mv_twsi_write),
DEVMETHOD(iicbus_read, mv_twsi_read),
DEVMETHOD(iicbus_reset, mv_twsi_reset),
DEVMETHOD(iicbus_transfer, iicbus_transfer_gen),
{ 0, 0 }
};
static devclass_t mv_twsi_devclass;
static driver_t mv_twsi_driver = {
MV_TWSI_NAME,
mv_twsi_methods,
sizeof(struct mv_twsi_softc),
};
DRIVER_MODULE(twsi, simplebus, mv_twsi_driver, mv_twsi_devclass, 0, 0);
DRIVER_MODULE(iicbus, twsi, iicbus_driver, iicbus_devclass, 0, 0);
MODULE_DEPEND(twsi, iicbus, 1, 1, 1);
static __inline uint32_t
TWSI_READ(struct mv_twsi_softc *sc, bus_size_t off)
{
return (bus_read_4(sc->res[0], off));
}
static __inline void
TWSI_WRITE(struct mv_twsi_softc *sc, bus_size_t off, uint32_t val)
{
bus_write_4(sc->res[0], off, val);
}
static __inline void
twsi_control_clear(struct mv_twsi_softc *sc, uint32_t mask)
{
uint32_t val;
val = TWSI_READ(sc, TWSI_CONTROL);
val &= ~mask;
TWSI_WRITE(sc, TWSI_CONTROL, val);
}
static __inline void
twsi_control_set(struct mv_twsi_softc *sc, uint32_t mask)
{
uint32_t val;
val = TWSI_READ(sc, TWSI_CONTROL);
val |= mask;
TWSI_WRITE(sc, TWSI_CONTROL, val);
}
static __inline void
twsi_clear_iflg(struct mv_twsi_softc *sc)
{
DELAY(1000);
twsi_control_clear(sc, TWSI_CONTROL_IFLG);
DELAY(1000);
}
/*
* timeout given in us
* returns
* 0 on sucessfull mask change
* non-zero on timeout
*/
static int
twsi_poll_ctrl(struct mv_twsi_softc *sc, int timeout, uint32_t mask)
{
timeout /= 10;
while (!(TWSI_READ(sc, TWSI_CONTROL) & mask)) {
DELAY(10);
if (--timeout < 0)
return (timeout);
}
return (0);
}
/*
* 'timeout' is given in us. Note also that timeout handling is not exact --
* twsi_locked_start() total wait can be more than 2 x timeout
* (twsi_poll_ctrl() is called twice). 'mask' can be either TWSI_STATUS_START
* or TWSI_STATUS_RPTD_START
*/
static int
twsi_locked_start(device_t dev, struct mv_twsi_softc *sc, int32_t mask,
u_char slave, int timeout)
{
int read_access, iflg_set = 0;
uint32_t status;
mtx_assert(&sc->mutex, MA_OWNED);
if (mask == TWSI_STATUS_RPTD_START)
/* read IFLG to know if it should be cleared later; from NBSD */
iflg_set = TWSI_READ(sc, TWSI_CONTROL) & TWSI_CONTROL_IFLG;
twsi_control_set(sc, TWSI_CONTROL_START);
if (mask == TWSI_STATUS_RPTD_START && iflg_set) {
debugf("IFLG set, clearing\n");
twsi_clear_iflg(sc);
}
/*
* Without this delay we timeout checking IFLG if the timeout is 0.
* NBSD driver always waits here too.
*/
DELAY(1000);
if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
debugf("timeout sending %sSTART condition\n",
mask == TWSI_STATUS_START ? "" : "repeated ");
return (IIC_ETIMEOUT);
}
status = TWSI_READ(sc, TWSI_STATUS);
if (status != mask) {
debugf("wrong status (%02x) after sending %sSTART condition\n",
status, mask == TWSI_STATUS_START ? "" : "repeated ");
return (IIC_ESTATUS);
}
TWSI_WRITE(sc, TWSI_DATA, slave);
DELAY(1000);
twsi_clear_iflg(sc);
if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
debugf("timeout sending slave address\n");
return (IIC_ETIMEOUT);
}
read_access = (slave & 0x1) ? 1 : 0;
status = TWSI_READ(sc, TWSI_STATUS);
if (status != (read_access ?
TWSI_STATUS_ADDR_R_ACK : TWSI_STATUS_ADDR_W_ACK)) {
debugf("no ACK (status: %02x) after sending slave address\n",
status);
return (IIC_ENOACK);
}
return (IIC_NOERR);
}
static int
mv_twsi_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "mrvl,twsi"))
return (ENXIO);
device_set_desc(dev, "Marvell Integrated I2C Bus Controller");
return (BUS_PROBE_DEFAULT);
}
#define ABSSUB(a,b) (((a) > (b)) ? (a) - (b) : (b) - (a))
static void
mv_twsi_cal_baud_rate(const uint32_t target, struct mv_twsi_baud_rate *rate)
{
uint32_t clk, cur, diff, diff0;
int m, n, m0, n0;
/* Calculate baud rate. */
m0 = n0 = 4; /* Default values on reset */
diff0 = 0xffffffff;
clk = get_tclk();
for (n = 0; n < 8; n++) {
for (m = 0; m < 16; m++) {
cur = TWSI_BAUD_RATE_RAW(clk,m,n);
diff = ABSSUB(target, cur);
if (diff < diff0) {
m0 = m;
n0 = n;
diff0 = diff;
}
}
}
rate->raw = TWSI_BAUD_RATE_RAW(clk, m0, n0);
rate->param = TWSI_BAUD_RATE_PARAM(m0, n0);
rate->m = m0;
rate->n = n0;
}
static int
mv_twsi_attach(device_t dev)
{
struct mv_twsi_softc *sc;
phandle_t child, iicbusnode;
device_t childdev;
struct iicbus_ivar *devi;
char dname[32]; /* 32 is taken from struct u_device */
uint32_t paddr;
int len, error;
sc = device_get_softc(dev);
sc->dev = dev;
bzero(baud_rate, sizeof(baud_rate));
mtx_init(&sc->mutex, device_get_nameunit(dev), MV_TWSI_NAME, MTX_DEF);
/* Allocate IO resources */
if (bus_alloc_resources(dev, res_spec, sc->res)) {
device_printf(dev, "could not allocate resources\n");
mv_twsi_detach(dev);
return (ENXIO);
}
mv_twsi_cal_baud_rate(TWSI_BAUD_RATE_SLOW, &baud_rate[IIC_SLOW]);
mv_twsi_cal_baud_rate(TWSI_BAUD_RATE_FAST, &baud_rate[IIC_FAST]);
if (bootverbose)
device_printf(dev, "calculated baud rates are:\n"
" %" PRIu32 " kHz (M=%d, N=%d) for slow,\n"
" %" PRIu32 " kHz (M=%d, N=%d) for fast.\n",
baud_rate[IIC_SLOW].raw / 1000,
baud_rate[IIC_SLOW].m,
baud_rate[IIC_SLOW].n,
baud_rate[IIC_FAST].raw / 1000,
baud_rate[IIC_FAST].m,
baud_rate[IIC_FAST].n);
sc->iicbus = device_add_child(dev, IICBUS_DEVNAME, -1);
if (sc->iicbus == NULL) {
device_printf(dev, "could not add iicbus child\n");
mv_twsi_detach(dev);
return (ENXIO);
}
/* Attach iicbus. */
bus_generic_attach(dev);
iicbusnode = 0;
/* Find iicbus as the child devices in the device tree. */
for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
child = OF_peer(child)) {
len = OF_getproplen(child, "model");
if (len <= 0 || len > sizeof(dname) - 1)
continue;
error = OF_getprop(child, "model", &dname, len);
dname[len + 1] = '\0';
if (error == -1)
continue;
len = strlen(dname);
if (len == strlen(IICBUS_DEVNAME) &&
strncasecmp(dname, IICBUS_DEVNAME, len) == 0) {
iicbusnode = child;
break;
}
}
if (iicbusnode == 0)
goto attach_end;
/* Attach child devices onto iicbus. */
for (child = OF_child(iicbusnode); child != 0; child = OF_peer(child)) {
/* Get slave address. */
error = OF_getprop(child, "i2c-address", &paddr, sizeof(paddr));
if (error == -1)
error = OF_getprop(child, "reg", &paddr, sizeof(paddr));
if (error == -1)
continue;
/* Get device driver name. */
len = OF_getproplen(child, "model");
if (len <= 0 || len > sizeof(dname) - 1)
continue;
OF_getprop(child, "model", &dname, len);
dname[len + 1] = '\0';
if (bootverbose)
device_printf(dev, "adding a device %s at %d.\n",
dname, fdt32_to_cpu(paddr));
childdev = BUS_ADD_CHILD(sc->iicbus, 0, dname, -1);
devi = IICBUS_IVAR(childdev);
devi->addr = fdt32_to_cpu(paddr);
}
attach_end:
bus_generic_attach(sc->iicbus);
return (0);
}
static int
mv_twsi_detach(device_t dev)
{
struct mv_twsi_softc *sc;
int rv;
sc = device_get_softc(dev);
if ((rv = bus_generic_detach(dev)) != 0)
return (rv);
if (sc->iicbus != NULL)
if ((rv = device_delete_child(dev, sc->iicbus)) != 0)
return (rv);
bus_release_resources(dev, res_spec, sc->res);
mtx_destroy(&sc->mutex);
return (0);
}
/*
* Only slave mode supported, disregard [old]addr
*/
static int
mv_twsi_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
struct mv_twsi_softc *sc;
uint32_t param;
sc = device_get_softc(dev);
switch (speed) {
case IIC_SLOW:
case IIC_FAST:
param = baud_rate[speed].param;
break;
case IIC_FASTEST:
case IIC_UNKNOWN:
default:
param = baud_rate[IIC_FAST].param;
break;
}
mtx_lock(&sc->mutex);
TWSI_WRITE(sc, TWSI_SOFT_RESET, 0x0);
DELAY(2000);
TWSI_WRITE(sc, TWSI_BAUD_RATE, param);
TWSI_WRITE(sc, TWSI_CONTROL, TWSI_CONTROL_TWSIEN | TWSI_CONTROL_ACK);
DELAY(1000);
mtx_unlock(&sc->mutex);
return (0);
}
/*
* timeout is given in us
*/
static int
mv_twsi_repeated_start(device_t dev, u_char slave, int timeout)
{
struct mv_twsi_softc *sc;
int rv;
sc = device_get_softc(dev);
mtx_lock(&sc->mutex);
rv = twsi_locked_start(dev, sc, TWSI_STATUS_RPTD_START, slave,
timeout);
mtx_unlock(&sc->mutex);
if (rv) {
mv_twsi_stop(dev);
return (rv);
} else
return (IIC_NOERR);
}
/*
* timeout is given in us
*/
static int
mv_twsi_start(device_t dev, u_char slave, int timeout)
{
struct mv_twsi_softc *sc;
int rv;
sc = device_get_softc(dev);
mtx_lock(&sc->mutex);
rv = twsi_locked_start(dev, sc, TWSI_STATUS_START, slave, timeout);
mtx_unlock(&sc->mutex);
if (rv) {
mv_twsi_stop(dev);
return (rv);
} else
return (IIC_NOERR);
}
static int
mv_twsi_stop(device_t dev)
{
struct mv_twsi_softc *sc;
sc = device_get_softc(dev);
mtx_lock(&sc->mutex);
twsi_control_set(sc, TWSI_CONTROL_STOP);
DELAY(1000);
twsi_clear_iflg(sc);
mtx_unlock(&sc->mutex);
return (IIC_NOERR);
}
static int
mv_twsi_read(device_t dev, char *buf, int len, int *read, int last, int delay)
{
struct mv_twsi_softc *sc;
uint32_t status;
int last_byte, rv;
sc = device_get_softc(dev);
mtx_lock(&sc->mutex);
*read = 0;
while (*read < len) {
/*
* Check if we are reading last byte of the last buffer,
* do not send ACK then, per I2C specs
*/
last_byte = ((*read == len - 1) && last) ? 1 : 0;
if (last_byte)
twsi_control_clear(sc, TWSI_CONTROL_ACK);
else
twsi_control_set(sc, TWSI_CONTROL_ACK);
DELAY (1000);
twsi_clear_iflg(sc);
if (twsi_poll_ctrl(sc, delay, TWSI_CONTROL_IFLG)) {
debugf("timeout reading data\n");
rv = IIC_ETIMEOUT;
goto out;
}
status = TWSI_READ(sc, TWSI_STATUS);
if (status != (last_byte ?
TWSI_STATUS_DATA_RD_NOACK : TWSI_STATUS_DATA_RD_ACK)) {
debugf("wrong status (%02x) while reading\n", status);
rv = IIC_ESTATUS;
goto out;
}
*buf++ = TWSI_READ(sc, TWSI_DATA);
(*read)++;
}
rv = IIC_NOERR;
out:
mtx_unlock(&sc->mutex);
return (rv);
}
static int
mv_twsi_write(device_t dev, const char *buf, int len, int *sent, int timeout)
{
struct mv_twsi_softc *sc;
uint32_t status;
int rv;
sc = device_get_softc(dev);
mtx_lock(&sc->mutex);
*sent = 0;
while (*sent < len) {
TWSI_WRITE(sc, TWSI_DATA, *buf++);
twsi_clear_iflg(sc);
if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
debugf("timeout writing data\n");
rv = IIC_ETIMEOUT;
goto out;
}
status = TWSI_READ(sc, TWSI_STATUS);
if (status != TWSI_STATUS_DATA_WR_ACK) {
debugf("wrong status (%02x) while writing\n", status);
rv = IIC_ESTATUS;
goto out;
}
(*sent)++;
}
rv = IIC_NOERR;
out:
mtx_unlock(&sc->mutex);
return (rv);
}