freebsd-dev/sys/dev/iicbus/icee.c
Warner Losh 44a8153672 Don't do the busy dance in icee_open/close
We don't need to do the busy dance for this driver. It's handled by
destroy_dev() entirely. Since all we did was busy/unbusy in
open/close, just delete them. We therefore don't need to track closes
either.

Reviewed by: ian@
Differential Revision: https://reviews.freebsd.org/D26431
2020-09-14 23:30:04 +00:00

369 lines
9.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
*
* 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 THE AUTHOR ``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 AUTHOR 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("$FreeBSD$");
/*
* Generic IIC eeprom support, modeled after the AT24C family of products.
*/
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <machine/bus.h>
#ifdef FDT
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbus_if.h"
/*
* AT24 parts have a "write page size" that differs per-device, and a "read page
* size" that is always equal to the full device size. We define maximum values
* here to limit how long we occupy the bus with a single transfer, and because
* there are temporary buffers of these sizes allocated on the stack.
*/
#define MAX_RD_SZ 256 /* Largest read size we support */
#define MAX_WR_SZ 256 /* Largest write size we support */
struct icee_softc {
device_t dev; /* Myself */
struct cdev *cdev; /* user interface */
int addr; /* Slave address on the bus */
int size; /* How big am I? */
int type; /* What address type 8 or 16 bit? */
int wr_sz; /* What's the write page size */
};
#ifdef FDT
struct eeprom_desc {
int type;
int size;
int wr_sz;
const char *name;
};
static struct eeprom_desc type_desc[] = {
{ 8, 128, 8, "AT24C01"},
{ 8, 256, 8, "AT24C02"},
{ 8, 512, 16, "AT24C04"},
{ 8, 1024, 16, "AT24C08"},
{ 8, 2 * 1024, 16, "AT24C16"},
{16, 4 * 1024, 32, "AT24C32"},
{16, 8 * 1024, 32, "AT24C64"},
{16, 16 * 1024, 64, "AT24C128"},
{16, 32 * 1024, 64, "AT24C256"},
{16, 64 * 1024, 128, "AT24C512"},
{16, 128 * 1024, 256, "AT24CM01"},
};
static struct ofw_compat_data compat_data[] = {
{"atmel,24c01", (uintptr_t)(&type_desc[0])},
{"atmel,24c02", (uintptr_t)(&type_desc[1])},
{"atmel,24c04", (uintptr_t)(&type_desc[2])},
{"atmel,24c08", (uintptr_t)(&type_desc[3])},
{"atmel,24c16", (uintptr_t)(&type_desc[4])},
{"atmel,24c32", (uintptr_t)(&type_desc[5])},
{"atmel,24c64", (uintptr_t)(&type_desc[6])},
{"atmel,24c128", (uintptr_t)(&type_desc[7])},
{"atmel,24c256", (uintptr_t)(&type_desc[8])},
{"atmel,24c512", (uintptr_t)(&type_desc[9])},
{"atmel,24c1024", (uintptr_t)(&type_desc[10])},
{NULL, (uintptr_t)NULL},
};
#endif
#define CDEV2SOFTC(dev) ((dev)->si_drv1)
/* cdev routines */
static d_read_t icee_read;
static d_write_t icee_write;
static struct cdevsw icee_cdevsw =
{
.d_version = D_VERSION,
.d_read = icee_read,
.d_write = icee_write
};
#ifdef FDT
static int
icee_probe(device_t dev)
{
struct eeprom_desc *d;
if (!ofw_bus_status_okay(dev))
return (ENXIO);
d = (struct eeprom_desc *)
ofw_bus_search_compatible(dev, compat_data)->ocd_data;
if (d == NULL)
return (ENXIO);
device_set_desc(dev, d->name);
return (BUS_PROBE_DEFAULT);
}
static void
icee_init(struct icee_softc *sc)
{
struct eeprom_desc *d;
d = (struct eeprom_desc *)
ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data;
if (d == NULL)
return; /* attach will see sc->size == 0 and return error */
sc->size = d->size;
sc->type = d->type;
sc->wr_sz = d->wr_sz;
}
#else /* !FDT */
static int
icee_probe(device_t dev)
{
device_set_desc(dev, "I2C EEPROM");
return (BUS_PROBE_NOWILDCARD);
}
static void
icee_init(struct icee_softc *sc)
{
const char *dname;
int dunit;
dname = device_get_name(sc->dev);
dunit = device_get_unit(sc->dev);
resource_int_value(dname, dunit, "size", &sc->size);
resource_int_value(dname, dunit, "type", &sc->type);
resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz);
}
#endif /* FDT */
static int
icee_attach(device_t dev)
{
struct icee_softc *sc = device_get_softc(dev);
struct sysctl_ctx_list *ctx;
struct sysctl_oid_list *tree;
sc->dev = dev;
sc->addr = iicbus_get_addr(dev);
icee_init(sc);
if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) {
device_printf(sc->dev, "Missing config data, "
"these cannot be zero: size %d type %d wr_sz %d\n",
sc->size, sc->type, sc->wr_sz);
return (EINVAL);
}
if (bootverbose)
device_printf(dev, "size: %d bytes, addressing: %d-bits\n",
sc->size, sc->type);
sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT,
GID_WHEEL, 0600, "icee%d", device_get_unit(dev));
if (sc->cdev == NULL) {
return (ENOMEM);
}
sc->cdev->si_drv1 = sc;
ctx = device_get_sysctl_ctx(dev);
tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev));
SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "address_size", CTLFLAG_RD,
&sc->type, 0, "Memory array address size in bits");
SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "device_size", CTLFLAG_RD,
&sc->size, 0, "Memory array capacity in bytes");
SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "write_size", CTLFLAG_RD,
&sc->wr_sz, 0, "Memory array page write size in bytes");
return (0);
}
static int
icee_detach(device_t dev)
{
struct icee_softc *sc = device_get_softc(dev);
destroy_dev(sc->cdev);
return (0);
}
static int
icee_read(struct cdev *dev, struct uio *uio, int ioflag)
{
struct icee_softc *sc;
uint8_t addr[2];
uint8_t data[MAX_RD_SZ];
int error, i, len, slave;
struct iic_msg msgs[2] = {
{ 0, IIC_M_WR, 1, addr },
{ 0, IIC_M_RD, 0, data },
};
sc = CDEV2SOFTC(dev);
if (uio->uio_offset == sc->size)
return (0);
if (uio->uio_offset > sc->size)
return (EIO);
if (sc->type != 8 && sc->type != 16)
return (EINVAL);
slave = error = 0;
while (uio->uio_resid > 0) {
if (uio->uio_offset >= sc->size)
break;
len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
uio->uio_resid);
switch (sc->type) {
case 8:
slave = (uio->uio_offset >> 7) | sc->addr;
msgs[0].len = 1;
msgs[1].len = len;
addr[0] = uio->uio_offset & 0xff;
break;
case 16:
slave = sc->addr | (uio->uio_offset >> 15);
msgs[0].len = 2;
msgs[1].len = len;
addr[0] = (uio->uio_offset >> 8) & 0xff;
addr[1] = uio->uio_offset & 0xff;
break;
}
for (i = 0; i < 2; i++)
msgs[i].slave = slave;
error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
if (error) {
error = iic2errno(error);
break;
}
error = uiomove(data, len, uio);
if (error)
break;
}
return (error);
}
/*
* Write to the part. We use three transfers here since we're actually
* doing a write followed by a read to make sure that the write finished.
* It is easier to encode the dummy read here than to break things up
* into smaller chunks...
*/
static int
icee_write(struct cdev *dev, struct uio *uio, int ioflag)
{
struct icee_softc *sc;
int error, len, slave, waitlimit;
uint8_t data[MAX_WR_SZ + 2];
struct iic_msg wr[1] = {
{ 0, IIC_M_WR, 0, data },
};
struct iic_msg rd[1] = {
{ 0, IIC_M_RD, 1, data },
};
sc = CDEV2SOFTC(dev);
if (uio->uio_offset >= sc->size)
return (EIO);
if (sc->type != 8 && sc->type != 16)
return (EINVAL);
slave = error = 0;
while (uio->uio_resid > 0) {
if (uio->uio_offset >= sc->size)
break;
len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)),
uio->uio_resid);
switch (sc->type) {
case 8:
slave = (uio->uio_offset >> 7) | sc->addr;
wr[0].len = 1 + len;
data[0] = uio->uio_offset & 0xff;
break;
case 16:
slave = sc->addr | (uio->uio_offset >> 15);
wr[0].len = 2 + len;
data[0] = (uio->uio_offset >> 8) & 0xff;
data[1] = uio->uio_offset & 0xff;
break;
}
wr[0].slave = slave;
error = uiomove(data + sc->type / 8, len, uio);
if (error)
break;
error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
if (error) {
error = iic2errno(error);
break;
}
/* Read after write to wait for write-done. */
waitlimit = 10000;
rd[0].slave = slave;
do {
error = iicbus_transfer_excl(sc->dev, rd, 1,
IIC_INTRWAIT);
} while (waitlimit-- > 0 && error != 0);
if (error) {
error = iic2errno(error);
break;
}
}
return error;
}
static device_method_t icee_methods[] = {
DEVMETHOD(device_probe, icee_probe),
DEVMETHOD(device_attach, icee_attach),
DEVMETHOD(device_detach, icee_detach),
DEVMETHOD_END
};
static driver_t icee_driver = {
"icee",
icee_methods,
sizeof(struct icee_softc),
};
static devclass_t icee_devclass;
DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0);
MODULE_VERSION(icee, 1);
MODULE_DEPEND(icee, iicbus, 1, 1, 1);
IICBUS_FDT_PNP_INFO(compat_data);