Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 24 Jan 2016 18:54:55 +0000 (UTC)
From:      Ian Lepore <ian@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org
Subject:   svn commit: r294674 - stable/10/sys/dev/iicbus
Message-ID:  <201601241854.u0OIstlU070040@repo.freebsd.org>

next in thread | raw e-mail | index | archive | help
Author: ian
Date: Sun Jan 24 18:54:55 2016
New Revision: 294674
URL: https://svnweb.freebsd.org/changeset/base/294674

Log:
  MFC r289727:
  
    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.

Modified:
  stable/10/sys/dev/iicbus/icee.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/iicbus/icee.c
==============================================================================
--- stable/10/sys/dev/iicbus/icee.c	Sun Jan 24 18:54:11 2016	(r294673)
+++ stable/10/sys/dev/iicbus/icee.c	Sun Jan 24 18:54:55 2016	(r294674)
@@ -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;
 }
 



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201601241854.u0OIstlU070040>