Author: ian
Date: Thu Oct 22 01:04:31 2015
New Revision: 289727
URL: https://svnweb.freebsd.org/changeset/base/289727
Log:
Add FDT compatibility to the icee driver.
The FDT bindings for eeprom parts don't include any metadata about the
device other than the part name encoded in the compatible property.
Instead, a driver is required to have a compiled-in table of information
about the various parts (page size, device capacity, addressing scheme). So
much for FDT being an abstract description of hardware characteristics, huh?
In addition to the FDT-specific changes, this also switches to using the
newer iicbus_transfer_excl() mechanism which holds bus ownership for the
duration of the transfer. Previously this code held the bus across all
the transfers needed to complete the user's IO request, which could be
up to 128KB of data which might occupy the bus for 10-20 seconds. Now the
bus will be released and re-aquired between every page-sized (8-256 byte)
transfer, making this driver a much nicer citizen on the i2c bus.
The hint-based configuration mechanism is still in place for non-FDT systems.
Michal Meloun contributed some of the code for these changes.
Modified:
head/sys/dev/iicbus/icee.c
Modified: head/sys/dev/iicbus/icee.c
==============================================================================
--- head/sys/dev/iicbus/icee.c Thu Oct 22 00:54:59 2015 (r289726)
+++ head/sys/dev/iicbus/icee.c Thu Oct 22 01:04:31 2015 (r289727)
@@ -27,6 +27,9 @@ __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>
@@ -37,26 +40,73 @@ __FBSDID("$FreeBSD$");
#include <sys/sx.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"
-#define IIC_M_WR 0 /* write operation */
+/*
+ * 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 */
+#define MAX_WR_SZ 256 /* Largest write size we support */
struct icee_softc {
- device_t sc_dev; /* Myself */
- device_t sc_busdev; /* Parent bus */
+ device_t dev; /* Myself */
struct cdev *cdev; /* user interface */
- int addr;
+ int addr; /* Slave address on the bus */
int size; /* How big am I? */
- int type; /* What type 8 or 16 bit? */
- int rd_sz; /* What's the read page size */
+ 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 */
@@ -75,6 +125,39 @@ static struct cdevsw icee_cdevsw =
.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)
{
@@ -83,37 +166,44 @@ icee_probe(device_t dev)
return (BUS_PROBE_NOWILDCARD);
}
-static int
-icee_attach(device_t dev)
+static void
+icee_init(struct icee_softc *sc)
{
- struct icee_softc *sc = device_get_softc(dev);
const char *dname;
- int dunit, err;
+ int dunit;
- sc->sc_dev = dev;
- sc->sc_busdev = device_get_parent(sc->sc_dev);
- sc->addr = iicbus_get_addr(dev);
- err = 0;
- dname = device_get_name(dev);
- dunit = device_get_unit(dev);
+ 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, "rd_sz", &sc->rd_sz);
- if (sc->rd_sz > MAX_RD_SZ)
- sc->rd_sz = MAX_RD_SZ;
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);
+
+ 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 bus_width: %d-bits\n",
+ 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) {
- err = ENOMEM;
- goto out;
+ return (ENOMEM);
}
sc->cdev->si_drv1 = sc;
-out:
- return (err);
+ return (0);
}
static int
@@ -149,14 +239,11 @@ icee_read(struct cdev *dev, struct uio *
return (EIO);
if (sc->type != 8 && sc->type != 16)
return (EINVAL);
- error = iicbus_request_bus(sc->sc_busdev, sc->sc_dev, IIC_INTRWAIT);
- if (error!= 0)
- return (iic2errno(error));
slave = error = 0;
while (uio->uio_resid > 0) {
if (uio->uio_offset >= sc->size)
break;
- len = MIN(sc->rd_sz - (uio->uio_offset & (sc->rd_sz - 1)),
+ len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)),
uio->uio_resid);
switch (sc->type) {
case 8:
@@ -175,7 +262,7 @@ icee_read(struct cdev *dev, struct uio *
}
for (i = 0; i < 2; i++)
msgs[i].slave = slave;
- error = iicbus_transfer(sc->sc_dev, msgs, 2);
+ error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT);
if (error) {
error = iic2errno(error);
break;
@@ -184,7 +271,6 @@ icee_read(struct cdev *dev, struct uio *
if (error)
break;
}
- iicbus_release_bus(sc->sc_busdev, sc->sc_dev);
return (error);
}
@@ -213,9 +299,6 @@ icee_write(struct cdev *dev, struct uio
if (sc->type != 8 && sc->type != 16)
return (EINVAL);
- error = iicbus_request_bus(sc->sc_busdev, sc->sc_dev, IIC_INTRWAIT);
- if (error!= 0)
- return (iic2errno(error));
slave = error = 0;
while (uio->uio_resid > 0) {
if (uio->uio_offset >= sc->size)
@@ -239,7 +322,7 @@ icee_write(struct cdev *dev, struct uio
error = uiomove(data + sc->type / 8, len, uio);
if (error)
break;
- error = iicbus_transfer(sc->sc_dev, wr, 1);
+ error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT);
if (error) {
error = iic2errno(error);
break;
@@ -248,14 +331,14 @@ icee_write(struct cdev *dev, struct uio
waitlimit = 10000;
rd[0].slave = slave;
do {
- error = iicbus_transfer(sc->sc_dev, rd, 1);
+ error = iicbus_transfer_excl(sc->dev, rd, 1,
+ IIC_INTRWAIT);
} while (waitlimit-- > 0 && error != 0);
if (error) {
error = iic2errno(error);
break;
}
}
- iicbus_release_bus(sc->sc_busdev, sc->sc_dev);
return error;
}
_______________________________________________
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
