i2c: introduce locking at a per-port level

There's also provisions to allow a pad to be locked with a specific
routing, for an indefinite period of time.  This will be used in
future patches.

The G94+ pad driver will now also power-down pads when not required.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

19 files changed, 387 insertions, 34 deletions

diff --git a/drm/Kbuild b/drm/Kbuild
index ee4a557e..d647e748 100644
--- a/drm/Kbuild
+++ b/drm/Kbuild
@@ -132,6 +132,9 @@ nouveau-y += core/subdev/i2c/base.o
 nouveau-y += core/subdev/i2c/anx9805.o
 nouveau-y += core/subdev/i2c/aux.o
 nouveau-y += core/subdev/i2c/bit.o
+nouveau-y += core/subdev/i2c/pad.o
+nouveau-y += core/subdev/i2c/padnv04.o
+nouveau-y += core/subdev/i2c/padnv94.o
 nouveau-y += core/subdev/i2c/nv04.o
 nouveau-y += core/subdev/i2c/nv4e.o
 nouveau-y += core/subdev/i2c/nv50.o
diff --git a/drm/core/subdev/i2c/pad.c b/drm/core/subdev/i2c/pad.c
new file mode 120000
index 00000000..3f384bf1
--- /dev/null
+++ b/drm/core/subdev/i2c/pad.c
@@ -0,0 +1 @@
+../../../../nvkm/subdev/i2c/pad.c
\ No newline at end of file
diff --git a/drm/core/subdev/i2c/pad.h b/drm/core/subdev/i2c/pad.h
new file mode 120000
index 00000000..d6ac100b
--- /dev/null
+++ b/drm/core/subdev/i2c/pad.h
@@ -0,0 +1 @@
+../../../../nvkm/subdev/i2c/pad.h
\ No newline at end of file
diff --git a/drm/core/subdev/i2c/padnv04.c b/drm/core/subdev/i2c/padnv04.c
new file mode 120000
index 00000000..5ee9dfef
--- /dev/null
+++ b/drm/core/subdev/i2c/padnv04.c
@@ -0,0 +1 @@
+../../../../nvkm/subdev/i2c/padnv04.c
\ No newline at end of file
diff --git a/drm/core/subdev/i2c/padnv94.c b/drm/core/subdev/i2c/padnv94.c
new file mode 120000
index 00000000..77fd1ad3
--- /dev/null
+++ b/drm/core/subdev/i2c/padnv94.c
@@ -0,0 +1 @@
+../../../../nvkm/subdev/i2c/padnv94.c
\ No newline at end of file
diff --git a/nvkm/include/subdev/i2c.h b/nvkm/include/subdev/i2c.h
index 9c150568..db1b39d0 100644
--- a/nvkm/include/subdev/i2c.h
+++ b/nvkm/include/subdev/i2c.h
@@ -28,6 +28,7 @@ enum nvkm_i2c_event {
 struct nouveau_i2c_port {
 	struct nouveau_object base;
 	struct i2c_adapter adapter;
+	struct mutex mutex;
 
 	struct list_head head;
 	u8  index;
@@ -37,9 +38,6 @@ struct nouveau_i2c_port {
 };
 
 struct nouveau_i2c_func {
-	void (*acquire)(struct nouveau_i2c_port *);
-	void (*release)(struct nouveau_i2c_port *);
-
 	void (*drive_scl)(struct nouveau_i2c_port *, int);
 	void (*drive_sda)(struct nouveau_i2c_port *, int);
 	int  (*sense_scl)(struct nouveau_i2c_port *);
@@ -62,12 +60,16 @@ struct nouveau_i2c {
 
 	struct nouveau_i2c_port *(*find)(struct nouveau_i2c *, u8 index);
 	struct nouveau_i2c_port *(*find_type)(struct nouveau_i2c *, u16 type);
+	int  (*acquire_pad)(struct nouveau_i2c_port *, unsigned long timeout);
+	void (*release_pad)(struct nouveau_i2c_port *);
 	int  (*acquire)(struct nouveau_i2c_port *, unsigned long timeout);
 	void (*release)(struct nouveau_i2c_port *);
 	int (*identify)(struct nouveau_i2c *, int index,
 			const char *what, struct nouveau_i2c_board_info *,
 			bool (*match)(struct nouveau_i2c_port *,
 				      struct i2c_board_info *, void *), void *);
+
+	wait_queue_head_t wait;
 	struct list_head ports;
 };
 
diff --git a/nvkm/subdev/i2c/Makefile.am b/nvkm/subdev/i2c/Makefile.am
index 8dda986e..729207a3 100644
--- a/nvkm/subdev/i2c/Makefile.am
+++ b/nvkm/subdev/i2c/Makefile.am
@@ -4,6 +4,9 @@ libi2c_la_SOURCES = base.c \
 		    anx9805.c \
 		    aux.c \
 		    bit.c \
+		    pad.c \
+		    padnv04.c \
+		    padnv94.c \
 		    nv04.c \
 		    nv4e.c \
 		    nv50.c \
diff --git a/nvkm/subdev/i2c/base.c b/nvkm/subdev/i2c/base.c
index a230465f..09ba2cc8 100644
--- a/nvkm/subdev/i2c/base.c
+++ b/nvkm/subdev/i2c/base.c
@@ -31,6 +31,7 @@
 #include <subdev/vga.h>
 
 #include "priv.h"
+#include "pad.h"
 
 /******************************************************************************
  * interface to linux i2c bit-banging algorithm
@@ -90,6 +91,15 @@ nouveau_i2c_getsda(void *data)
  * base i2c "port" class implementation
  *****************************************************************************/
 
+int
+_nouveau_i2c_port_fini(struct nouveau_object *object, bool suspend)
+{
+	struct nouveau_i2c_port *port = (void *)object;
+	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
+	nv_ofuncs(pad)->fini(nv_object(pad), suspend);
+	return nouveau_object_fini(&port->base, suspend);
+}
+
 void
 _nouveau_i2c_port_dtor(struct nouveau_object *object)
 {
@@ -106,7 +116,7 @@ nouveau_i2c_port_create_(struct nouveau_object *parent,
 			 const struct nouveau_i2c_func *func,
 			 int size, void **pobject)
 {
-	struct nouveau_device *device = nv_device(parent);
+	struct nouveau_device *device = nv_device(engine);
 	struct nouveau_i2c *i2c = (void *)engine;
 	struct nouveau_i2c_port *port;
 	int ret;
@@ -123,6 +133,7 @@ nouveau_i2c_port_create_(struct nouveau_object *parent,
 	port->index = index;
 	port->aux = -1;
 	port->func = func;
+	mutex_init(&port->mutex);
 
 	if ( algo == &nouveau_i2c_bit_algo &&
 	    !nouveau_boolopt(device->cfgopt, "NvI2C", CSTMSEL)) {
@@ -202,18 +213,72 @@ nouveau_i2c_find_type(struct nouveau_i2c *i2c, u16 type)
 }
 
 static void
+nouveau_i2c_release_pad(struct nouveau_i2c_port *port)
+{
+	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
+	struct nouveau_i2c *i2c = nouveau_i2c(port);
+
+	if (atomic_dec_and_test(&nv_object(pad)->usecount)) {
+		nv_ofuncs(pad)->fini(nv_object(pad), false);
+		wake_up_all(&i2c->wait);
+	}
+}
+
+static int
+nouveau_i2c_try_acquire_pad(struct nouveau_i2c_port *port)
+{
+	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
+
+	if (atomic_add_return(1, &nv_object(pad)->usecount) != 1) {
+		struct nouveau_object *owner = (void *)pad->port;
+		do {
+			if (owner == (void *)port)
+				return 0;
+			owner = owner->parent;
+		} while(owner);
+		nouveau_i2c_release_pad(port);
+		return -EBUSY;
+	}
+
+	pad->next = port;
+	nv_ofuncs(pad)->init(nv_object(pad));
+	return 0;
+}
+
+static int
+nouveau_i2c_acquire_pad(struct nouveau_i2c_port *port, unsigned long timeout)
+{
+	struct nouveau_i2c *i2c = nouveau_i2c(port);
+
+	if (timeout) {
+		if (wait_event_timeout(i2c->wait,
+				       nouveau_i2c_try_acquire_pad(port) == 0,
+				       timeout) == 0)
+			return -EBUSY;
+	} else {
+		wait_event(i2c->wait, nouveau_i2c_try_acquire_pad(port) == 0);
+	}
+
+	return 0;
+}
+
+static void
 nouveau_i2c_release(struct nouveau_i2c_port *port)
+__releases(pad->mutex)
 {
-	if (port->func->release)
-		port->func->release(port);
+	nouveau_i2c(port)->release_pad(port);
+	mutex_unlock(&port->mutex);
 }
 
 static int
 nouveau_i2c_acquire(struct nouveau_i2c_port *port, unsigned long timeout)
+__acquires(pad->mutex)
 {
-	if (port->func->acquire)
-		port->func->acquire(port);
-	return 0;
+	int ret;
+	mutex_lock(&port->mutex);
+	if ((ret = nouveau_i2c(port)->acquire_pad(port, timeout)))
+		mutex_unlock(&port->mutex);
+	return ret;
 }
 
 static int
@@ -391,7 +456,7 @@ nouveau_i2c_create_(struct nouveau_object *parent,
 	struct nouveau_i2c *i2c;
 	struct nouveau_object *object;
 	struct dcb_i2c_entry info;
-	int ret, i, j, index = -1;
+	int ret, i, j, index = -1, pad;
 	struct dcb_output outp;
 	u8  ver, hdr;
 	u32 data;
@@ -405,24 +470,45 @@ nouveau_i2c_create_(struct nouveau_object *parent,
 	nv_subdev(i2c)->intr = nouveau_i2c_intr;
 	i2c->find = nouveau_i2c_find;
 	i2c->find_type = nouveau_i2c_find_type;
+	i2c->acquire_pad = nouveau_i2c_acquire_pad;
+	i2c->release_pad = nouveau_i2c_release_pad;
 	i2c->acquire = nouveau_i2c_acquire;
 	i2c->release = nouveau_i2c_release;
 	i2c->identify = nouveau_i2c_identify;
+	init_waitqueue_head(&i2c->wait);
 	INIT_LIST_HEAD(&i2c->ports);
 
 	while (!dcb_i2c_parse(bios, ++index, &info)) {
 		if (info.type == DCB_I2C_UNUSED)
 			continue;
 
+		if (info.share != DCB_I2C_UNUSED) {
+			if (info.type == DCB_I2C_NVIO_AUX)
+				pad = info.drive;
+			else
+				pad = info.share;
+			oclass = impl->pad_s;
+		} else {
+			pad = 0x100 + info.drive;
+			oclass = impl->pad_x;
+		}
+
+		ret = nouveau_object_ctor(NULL, *pobject, oclass,
+					  NULL, pad, &parent);
+		if (ret < 0)
+			continue;
+
 		oclass = impl->sclass;
 		do {
 			ret = -EINVAL;
 			if (oclass->handle == info.type) {
-				ret = nouveau_object_ctor(*pobject, *pobject,
+				ret = nouveau_object_ctor(parent, *pobject,
 							  oclass, &info,
 							  index, &object);
 			}
 		} while (ret && (++oclass)->handle);
+
+		nouveau_object_ref(NULL, &parent);
 	}
 
 	/* in addition to the busses specified in the i2c table, there
diff --git a/nvkm/subdev/i2c/nv04.c b/nvkm/subdev/i2c/nv04.c
index a37528d5..b1725bde 100644
--- a/nvkm/subdev/i2c/nv04.c
+++ b/nvkm/subdev/i2c/nv04.c
@@ -126,4 +126,5 @@ nv04_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nv04_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
 }.base;
diff --git a/nvkm/subdev/i2c/nv4e.c b/nvkm/subdev/i2c/nv4e.c
index d97101b3..f16c87ce 100644
--- a/nvkm/subdev/i2c/nv4e.c
+++ b/nvkm/subdev/i2c/nv4e.c
@@ -118,4 +118,5 @@ nv4e_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nv4e_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
 }.base;
diff --git a/nvkm/subdev/i2c/nv50.c b/nvkm/subdev/i2c/nv50.c
index bb854981..7b8756d4 100644
--- a/nvkm/subdev/i2c/nv50.c
+++ b/nvkm/subdev/i2c/nv50.c
@@ -131,4 +131,5 @@ nv50_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nv50_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
 }.base;
diff --git a/nvkm/subdev/i2c/nv94.c b/nvkm/subdev/i2c/nv94.c
index ec0bd68a..f59c3a25 100644
--- a/nvkm/subdev/i2c/nv94.c
+++ b/nvkm/subdev/i2c/nv94.c
@@ -185,26 +185,8 @@ out:
 	return ret < 0 ? ret : (stat & 0x000f0000) >> 16;
 }
 
-void
-nv94_i2c_acquire(struct nouveau_i2c_port *base)
-{
-	struct nv50_i2c_priv *priv = (void *)nv_object(base)->engine;
-	struct nv50_i2c_port *port = (void *)base;
-	if (port->ctrl) {
-		nv_mask(priv, port->ctrl + 0x0c, 0x00000001, 0x00000000);
-		nv_mask(priv, port->ctrl + 0x00, 0x0000f003, port->data);
-	}
-}
-
-void
-nv94_i2c_release(struct nouveau_i2c_port *base)
-{
-}
-
 static const struct nouveau_i2c_func
 nv94_i2c_func = {
-	.acquire   = nv94_i2c_acquire,
-	.release   = nv94_i2c_release,
 	.drive_scl = nv50_i2c_drive_scl,
 	.drive_sda = nv50_i2c_drive_sda,
 	.sense_scl = nv50_i2c_sense_scl,
@@ -241,8 +223,6 @@ nv94_i2c_port_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
 
 static const struct nouveau_i2c_func
 nv94_aux_func = {
-	.acquire   = nv94_i2c_acquire,
-	.release   = nv94_i2c_release,
 	.aux       = nv94_aux,
 };
 
@@ -303,6 +283,8 @@ nv94_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nv94_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
+	.pad_s = &nv94_i2c_pad_oclass,
 	.aux = 4,
 	.aux_stat = nv94_aux_stat,
 	.aux_mask = nv94_aux_mask,
diff --git a/nvkm/subdev/i2c/nvd0.c b/nvkm/subdev/i2c/nvd0.c
index 35b8253f..364ddb1c 100644
--- a/nvkm/subdev/i2c/nvd0.c
+++ b/nvkm/subdev/i2c/nvd0.c
@@ -42,8 +42,6 @@ nvd0_i2c_sense_sda(struct nouveau_i2c_port *base)
 
 static const struct nouveau_i2c_func
 nvd0_i2c_func = {
-	.acquire   = nv94_i2c_acquire,
-	.release   = nv94_i2c_release,
 	.drive_scl = nv50_i2c_drive_scl,
 	.drive_sda = nv50_i2c_drive_sda,
 	.sense_scl = nvd0_i2c_sense_scl,
@@ -106,6 +104,8 @@ nvd0_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nvd0_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
+	.pad_s = &nv94_i2c_pad_oclass,
 	.aux = 4,
 	.aux_stat = nv94_aux_stat,
 	.aux_mask = nv94_aux_mask,
diff --git a/nvkm/subdev/i2c/nve0.c b/nvkm/subdev/i2c/nve0.c
index fb53389a..cae77e1a 100644
--- a/nvkm/subdev/i2c/nve0.c
+++ b/nvkm/subdev/i2c/nve0.c
@@ -64,6 +64,8 @@ nve0_i2c_oclass = &(struct nouveau_i2c_impl) {
 		.fini = _nouveau_i2c_fini,
 	},
 	.sclass = nvd0_i2c_sclass,
+	.pad_x = &nv04_i2c_pad_oclass,
+	.pad_s = &nv94_i2c_pad_oclass,
 	.aux = 4,
 	.aux_stat = nve0_aux_stat,
 	.aux_mask = nve0_aux_mask,
diff --git a/nvkm/subdev/i2c/pad.c b/nvkm/subdev/i2c/pad.c
new file mode 100644
index 00000000..e9e41247
--- /dev/null
+++ b/nvkm/subdev/i2c/pad.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "pad.h"
+
+int
+_nvkm_i2c_pad_fini(struct nouveau_object *object, bool suspend)
+{
+	struct nvkm_i2c_pad *pad = (void *)object;
+	DBG("-> NULL\n");
+	pad->port = NULL;
+	return nouveau_object_fini(&pad->base, suspend);
+}
+
+int
+_nvkm_i2c_pad_init(struct nouveau_object *object)
+{
+	struct nvkm_i2c_pad *pad = (void *)object;
+	DBG("-> PORT:%02x\n", pad->next->index);
+	pad->port = pad->next;
+	return nouveau_object_init(&pad->base);
+}
+
+int
+nvkm_i2c_pad_create_(struct nouveau_object *parent,
+		     struct nouveau_object *engine,
+		     struct nouveau_oclass *oclass, int index,
+		     int size, void **pobject)
+{
+	struct nouveau_i2c *i2c = (void *)engine;
+	struct nouveau_i2c_port *port;
+	struct nvkm_i2c_pad *pad;
+	int ret;
+
+	list_for_each_entry(port, &i2c->ports, head) {
+		pad = nvkm_i2c_pad(port);
+		if (pad->index == index) {
+			atomic_inc(&nv_object(pad)->refcount);
+			*pobject = pad;
+			return 1;
+		}
+	}
+
+	ret = nouveau_object_create_(parent, engine, oclass, 0, size, pobject);
+	pad = *pobject;
+	if (ret)
+		return ret;
+
+	pad->index = index;
+	return 0;
+}
+
+int
+_nvkm_i2c_pad_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
+		   struct nouveau_oclass *oclass, void *data, u32 index,
+		   struct nouveau_object **pobject)
+{
+	struct nvkm_i2c_pad *pad;
+	int ret;
+	ret = nvkm_i2c_pad_create(parent, engine, oclass, index, &pad);
+	*pobject = nv_object(pad);
+	return ret;
+}
diff --git a/nvkm/subdev/i2c/pad.h b/nvkm/subdev/i2c/pad.h
new file mode 100644
index 00000000..452ac10c
--- /dev/null
+++ b/nvkm/subdev/i2c/pad.h
@@ -0,0 +1,58 @@
+#ifndef __NVKM_I2C_PAD_H__
+#define __NVKM_I2C_PAD_H__
+
+#include "priv.h"
+
+struct nvkm_i2c_pad {
+	struct nouveau_object base;
+	int index;
+	struct nouveau_i2c_port *port;
+	struct nouveau_i2c_port *next;
+};
+
+static inline struct nvkm_i2c_pad *
+nvkm_i2c_pad(struct nouveau_i2c_port *port)
+{
+	struct nouveau_object *pad = nv_object(port);
+	while (pad->parent)
+		pad = pad->parent;
+	return (void *)pad;
+}
+
+#define nvkm_i2c_pad_create(p,e,o,i,d)                                         \
+	nvkm_i2c_pad_create_((p), (e), (o), (i), sizeof(**d), (void **)d)
+#define nvkm_i2c_pad_destroy(p) ({                                             \
+	struct nvkm_i2c_pad *_p = (p);                                         \
+	_nvkm_i2c_pad_dtor(nv_object(_p));                                     \
+})
+#define nvkm_i2c_pad_init(p) ({                                                \
+	struct nvkm_i2c_pad *_p = (p);                                         \
+	_nvkm_i2c_pad_init(nv_object(_p));                                     \
+})
+#define nvkm_i2c_pad_fini(p,s) ({                                              \
+	struct nvkm_i2c_pad *_p = (p);                                         \
+	_nvkm_i2c_pad_fini(nv_object(_p), (s));                                \
+})
+
+int nvkm_i2c_pad_create_(struct nouveau_object *, struct nouveau_object *,
+			 struct nouveau_oclass *, int index, int, void **);
+
+int _nvkm_i2c_pad_ctor(struct nouveau_object *, struct nouveau_object *,
+		       struct nouveau_oclass *, void *, u32,
+		       struct nouveau_object **);
+#define _nvkm_i2c_pad_dtor nouveau_object_destroy
+int _nvkm_i2c_pad_init(struct nouveau_object *);
+int _nvkm_i2c_pad_fini(struct nouveau_object *, bool);
+
+#ifndef MSG
+#define MSG(l,f,a...) do {                                                     \
+	struct nvkm_i2c_pad *_pad = (void *)pad;                               \
+	nv_##l(nv_object(_pad)->engine, "PAD:%c:%02x: "f,                      \
+	       _pad->index >= 0x100 ? 'X' : 'S',                               \
+	       _pad->index >= 0x100 ? _pad->index - 0x100 : _pad->index, ##a); \
+} while(0)
+#define DBG(f,a...) MSG(debug, f, ##a)
+#define ERR(f,a...) MSG(error, f, ##a)
+#endif
+
+#endif
diff --git a/nvkm/subdev/i2c/padnv04.c b/nvkm/subdev/i2c/padnv04.c
new file mode 100644
index 00000000..2c4b6129
--- /dev/null
+++ b/nvkm/subdev/i2c/padnv04.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "pad.h"
+
+struct nouveau_oclass
+nv04_i2c_pad_oclass = {
+	.ofuncs = &(struct nouveau_ofuncs) {
+		.ctor = _nvkm_i2c_pad_ctor,
+		.dtor = _nvkm_i2c_pad_dtor,
+		.init = _nvkm_i2c_pad_init,
+		.fini = _nvkm_i2c_pad_fini,
+	},
+};
diff --git a/nvkm/subdev/i2c/padnv94.c b/nvkm/subdev/i2c/padnv94.c
new file mode 100644
index 00000000..0dc67530
--- /dev/null
+++ b/nvkm/subdev/i2c/padnv94.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "pad.h"
+
+struct nv94_i2c_pad {
+	struct nvkm_i2c_pad base;
+	int addr;
+};
+
+static int
+nv94_i2c_pad_fini(struct nouveau_object *object, bool suspend)
+{
+	struct nouveau_i2c *i2c = (void *)object->engine;
+	struct nv94_i2c_pad *pad = (void *)object;
+	nv_mask(i2c, 0x00e50c + pad->addr, 0x00000001, 0x00000001);
+	return nvkm_i2c_pad_fini(&pad->base, suspend);
+}
+
+static int
+nv94_i2c_pad_init(struct nouveau_object *object)
+{
+	struct nouveau_i2c *i2c = (void *)object->engine;
+	struct nv94_i2c_pad *pad = (void *)object;
+
+	switch (nv_oclass(pad->base.next)->handle) {
+	case NV_I2C_TYPE_DCBI2C(DCB_I2C_NVIO_AUX):
+		nv_mask(i2c, 0x00e500 + pad->addr, 0x0000c003, 0x00000002);
+		break;
+	case NV_I2C_TYPE_DCBI2C(DCB_I2C_NVIO_BIT):
+	default:
+		nv_mask(i2c, 0x00e500 + pad->addr, 0x0000c003, 0x0000c001);
+		break;
+	}
+
+	nv_mask(i2c, 0x00e50c + pad->addr, 0x00000001, 0x00000000);
+	return nvkm_i2c_pad_init(&pad->base);
+}
+
+static int
+nv94_i2c_pad_ctor(struct nouveau_object *parent, struct nouveau_object *engine,
+		  struct nouveau_oclass *oclass, void *data, u32 index,
+		  struct nouveau_object **pobject)
+{
+	struct nv94_i2c_pad *pad;
+	int ret;
+
+	ret = nvkm_i2c_pad_create(parent, engine, oclass, index, &pad);
+	*pobject = nv_object(pad);
+	if (ret)
+		return ret;
+
+	pad->addr = index * 0x50;;
+	return 0;
+}
+
+struct nouveau_oclass
+nv94_i2c_pad_oclass = {
+	.ofuncs = &(struct nouveau_ofuncs) {
+		.ctor = nv94_i2c_pad_ctor,
+		.dtor = _nvkm_i2c_pad_dtor,
+		.init = nv94_i2c_pad_init,
+		.fini = nv94_i2c_pad_fini,
+	},
+};
diff --git a/nvkm/subdev/i2c/priv.h b/nvkm/subdev/i2c/priv.h
index 9a1e420e..780090b6 100644
--- a/nvkm/subdev/i2c/priv.h
+++ b/nvkm/subdev/i2c/priv.h
@@ -3,6 +3,9 @@
 
 #include <subdev/i2c.h>
 
+extern struct nouveau_oclass nv04_i2c_pad_oclass;
+extern struct nouveau_oclass nv94_i2c_pad_oclass;
+
 #define nouveau_i2c_port_create(p,e,o,i,a,f,d)                                 \
 	nouveau_i2c_port_create_((p), (e), (o), (i), (a), (f),                 \
 				 sizeof(**d), (void **)d)
@@ -22,7 +25,7 @@ int nouveau_i2c_port_create_(struct nouveau_object *, struct nouveau_object *,
 			     int, void **);
 void _nouveau_i2c_port_dtor(struct nouveau_object *);
 #define _nouveau_i2c_port_init nouveau_object_init
-#define _nouveau_i2c_port_fini nouveau_object_fini
+int  _nouveau_i2c_port_fini(struct nouveau_object *, bool);
 
 #define nouveau_i2c_create(p,e,o,d)                                            \
 	nouveau_i2c_create_((p), (e), (o), sizeof(**d), (void **)d)
@@ -59,6 +62,8 @@ struct nouveau_i2c_impl {
 
 	/* supported i2c port classes */
 	struct nouveau_oclass *sclass;
+	struct nouveau_oclass *pad_x;
+	struct nouveau_oclass *pad_s;
 
 	/* number of native dp aux channels present */
 	int aux;