drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c - nest-learning-thermostat/5.7.1/linux-imx-ul - Git at Google

 /*
  * Copyright 2013 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 "priv.h"
 #include "pad.h"

 #include <core/device.h>
 #include <core/notify.h>
 #include <core/option.h>
 #include <subdev/bios.h>
 #include <subdev/bios/dcb.h>

 /******************************************************************************
  * interface to linux i2c bit-banging algorithm
  *****************************************************************************/

 #ifdef CONFIG_NOUVEAU_I2C_INTERNAL_DEFAULT
 #define CSTMSEL true
 #else
 #define CSTMSEL false
 #endif

 static int
 nvkm_i2c_pre_xfer(struct i2c_adapter *adap)
 {
 	struct i2c_algo_bit_data *bit = adap->algo_data;
 	struct nvkm_i2c_port *port = bit->data;
 	return nvkm_i2c(port)->acquire(port, bit->timeout);
 }

 static void
 nvkm_i2c_post_xfer(struct i2c_adapter *adap)
 {
 	struct i2c_algo_bit_data *bit = adap->algo_data;
 	struct nvkm_i2c_port *port = bit->data;
 	return nvkm_i2c(port)->release(port);
 }

 static void
 nvkm_i2c_setscl(void *data, int state)
 {
 	struct nvkm_i2c_port *port = data;
 	port->func->drive_scl(port, state);
 }

 static void
 nvkm_i2c_setsda(void *data, int state)
 {
 	struct nvkm_i2c_port *port = data;
 	port->func->drive_sda(port, state);
 }

 static int
 nvkm_i2c_getscl(void *data)
 {
 	struct nvkm_i2c_port *port = data;
 	return port->func->sense_scl(port);
 }

 static int
 nvkm_i2c_getsda(void *data)
 {
 	struct nvkm_i2c_port *port = data;
 	return port->func->sense_sda(port);
 }

 /******************************************************************************
  * base i2c "port" class implementation
  *****************************************************************************/

 int
 _nvkm_i2c_port_fini(struct nvkm_object *object, bool suspend)
 {
 	struct nvkm_i2c_port *port = (void *)object;
 	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
 	nv_ofuncs(pad)->fini(nv_object(pad), suspend);
 	return nvkm_object_fini(&port->base, suspend);
 }

 void
 _nvkm_i2c_port_dtor(struct nvkm_object *object)
 {
 	struct nvkm_i2c_port *port = (void *)object;
 	i2c_del_adapter(&port->adapter);
 	nvkm_object_destroy(&port->base);
 }

 int
 nvkm_i2c_port_create_(struct nvkm_object *parent, struct nvkm_object *engine,
 		      struct nvkm_oclass *oclass, u8 index,
 		      const struct i2c_algorithm *algo,
 		      const struct nvkm_i2c_func *func,
 		      int size, void **pobject)
 {
 	struct nvkm_device *device = nv_device(parent);
 	struct nvkm_i2c *i2c = nvkm_i2c(parent);
 	struct nvkm_i2c_port *port;
 	int ret;

 	ret = nvkm_object_create_(parent, engine, oclass, 0, size, pobject);
 	port = *pobject;
 	if (ret)
 		return ret;

 	snprintf(port->adapter.name, sizeof(port->adapter.name),
 		 "nvkm-%s-%d", device->name, index);
 	port->adapter.owner = THIS_MODULE;
 	port->adapter.dev.parent = nv_device_base(device);
 	port->index = index;
 	port->aux = -1;
 	port->func = func;
 	mutex_init(&port->mutex);

 	if ( algo == &nvkm_i2c_bit_algo &&
 	    !nvkm_boolopt(device->cfgopt, "NvI2C", CSTMSEL)) {
 		struct i2c_algo_bit_data *bit;

 		bit = kzalloc(sizeof(*bit), GFP_KERNEL);
 		if (!bit)
 			return -ENOMEM;

 		bit->udelay = 10;
 		bit->timeout = usecs_to_jiffies(2200);
 		bit->data = port;
 		bit->pre_xfer = nvkm_i2c_pre_xfer;
 		bit->post_xfer = nvkm_i2c_post_xfer;
 		bit->setsda = nvkm_i2c_setsda;
 		bit->setscl = nvkm_i2c_setscl;
 		bit->getsda = nvkm_i2c_getsda;
 		bit->getscl = nvkm_i2c_getscl;

 		port->adapter.algo_data = bit;
 		ret = i2c_bit_add_bus(&port->adapter);
 	} else {
 		port->adapter.algo_data = port;
 		port->adapter.algo = algo;
 		ret = i2c_add_adapter(&port->adapter);
 	}

 	if (ret == 0)
 		list_add_tail(&port->head, &i2c->ports);
 	return ret;
 }

 /******************************************************************************
  * base i2c subdev class implementation
  *****************************************************************************/

 static struct nvkm_i2c_port *
 nvkm_i2c_find(struct nvkm_i2c *i2c, u8 index)
 {
 	struct nvkm_bios *bios = nvkm_bios(i2c);
 	struct nvkm_i2c_port *port;

 	if (index == NV_I2C_DEFAULT(0) ||
 	    index == NV_I2C_DEFAULT(1)) {
 		u8  ver, hdr, cnt, len;
 		u16 i2c = dcb_i2c_table(bios, &ver, &hdr, &cnt, &len);
 		if (i2c && ver >= 0x30) {
 			u8 auxidx = nv_ro08(bios, i2c + 4);
 			if (index == NV_I2C_DEFAULT(0))
 				index = (auxidx & 0x0f) >> 0;
 			else
 				index = (auxidx & 0xf0) >> 4;
 		} else {
 			index = 2;
 		}
 	}

 	list_for_each_entry(port, &i2c->ports, head) {
 		if (port->index == index)
 			return port;
 	}

 	return NULL;
 }

 static struct nvkm_i2c_port *
 nvkm_i2c_find_type(struct nvkm_i2c *i2c, u16 type)
 {
 	struct nvkm_i2c_port *port;

 	list_for_each_entry(port, &i2c->ports, head) {
 		if (nv_hclass(port) == type)
 			return port;
 	}

 	return NULL;
 }

 static void
 nvkm_i2c_release_pad(struct nvkm_i2c_port *port)
 {
 	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
 	struct nvkm_i2c *i2c = nvkm_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
 nvkm_i2c_try_acquire_pad(struct nvkm_i2c_port *port)
 {
 	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);

 	if (atomic_add_return(1, &nv_object(pad)->usecount) != 1) {
 		struct nvkm_object *owner = (void *)pad->port;
 		do {
 			if (owner == (void *)port)
 				return 0;
 			owner = owner->parent;
 		} while(owner);
 		nvkm_i2c_release_pad(port);
 		return -EBUSY;
 	}

 	pad->next = port;
 	nv_ofuncs(pad)->init(nv_object(pad));
 	return 0;
 }

 static int
 nvkm_i2c_acquire_pad(struct nvkm_i2c_port *port, unsigned long timeout)
 {
 	struct nvkm_i2c *i2c = nvkm_i2c(port);

 	if (timeout) {
 		if (wait_event_timeout(i2c->wait,
 				       nvkm_i2c_try_acquire_pad(port) == 0,
 				       timeout) == 0)
 			return -EBUSY;
 	} else {
 		wait_event(i2c->wait, nvkm_i2c_try_acquire_pad(port) == 0);
 	}

 	return 0;
 }

 static void
 nvkm_i2c_release(struct nvkm_i2c_port *port)
 __releases(pad->mutex)
 {
 	nvkm_i2c(port)->release_pad(port);
 	mutex_unlock(&port->mutex);
 }

 static int
 nvkm_i2c_acquire(struct nvkm_i2c_port *port, unsigned long timeout)
 __acquires(pad->mutex)
 {
 	int ret;
 	mutex_lock(&port->mutex);
 	if ((ret = nvkm_i2c(port)->acquire_pad(port, timeout)))
 		mutex_unlock(&port->mutex);
 	return ret;
 }

 static int
 nvkm_i2c_identify(struct nvkm_i2c *i2c, int index, const char *what,
 		  struct nvkm_i2c_board_info *info,
 		  bool (*match)(struct nvkm_i2c_port *,
 				struct i2c_board_info *, void *), void *data)
 {
 	struct nvkm_i2c_port *port = nvkm_i2c_find(i2c, index);
 	int i;

 	if (!port) {
 		nv_debug(i2c, "no bus when probing %s on %d\n", what, index);
 		return -ENODEV;
 	}

 	nv_debug(i2c, "probing %ss on bus: %d\n", what, port->index);
 	for (i = 0; info[i].dev.addr; i++) {
 		u8 orig_udelay = 0;

 		if ((port->adapter.algo == &i2c_bit_algo) &&
 		    (info[i].udelay != 0)) {
 			struct i2c_algo_bit_data *algo = port->adapter.algo_data;
 			nv_debug(i2c, "using custom udelay %d instead of %d\n",
 			         info[i].udelay, algo->udelay);
 			orig_udelay = algo->udelay;
 			algo->udelay = info[i].udelay;
 		}

 		if (nv_probe_i2c(port, info[i].dev.addr) &&
 		    (!match || match(port, &info[i].dev, data))) {
 			nv_info(i2c, "detected %s: %s\n", what,
 				info[i].dev.type);
 			return i;
 		}

 		if (orig_udelay) {
 			struct i2c_algo_bit_data *algo = port->adapter.algo_data;
 			algo->udelay = orig_udelay;
 		}
 	}

 	nv_debug(i2c, "no devices found.\n");
 	return -ENODEV;
 }

 static void
 nvkm_i2c_intr_fini(struct nvkm_event *event, int type, int index)
 {
 	struct nvkm_i2c *i2c = container_of(event, typeof(*i2c), event);
 	struct nvkm_i2c_port *port = i2c->find(i2c, index);
 	const struct nvkm_i2c_impl *impl = (void *)nv_object(i2c)->oclass;
 	if (port && port->aux >= 0)
 		impl->aux_mask(i2c, type, 1 << port->aux, 0);
 }

 static void
 nvkm_i2c_intr_init(struct nvkm_event *event, int type, int index)
 {
 	struct nvkm_i2c *i2c = container_of(event, typeof(*i2c), event);
 	struct nvkm_i2c_port *port = i2c->find(i2c, index);
 	const struct nvkm_i2c_impl *impl = (void *)nv_object(i2c)->oclass;
 	if (port && port->aux >= 0)
 		impl->aux_mask(i2c, type, 1 << port->aux, 1 << port->aux);
 }

 static int
 nvkm_i2c_intr_ctor(struct nvkm_object *object, void *data, u32 size,
 		      struct nvkm_notify *notify)
 {
 	struct nvkm_i2c_ntfy_req *req = data;
 	if (!WARN_ON(size != sizeof(*req))) {
 		notify->size  = sizeof(struct nvkm_i2c_ntfy_rep);
 		notify->types = req->mask;
 		notify->index = req->port;
 		return 0;
 	}
 	return -EINVAL;
 }

 static void
 nvkm_i2c_intr(struct nvkm_subdev *subdev)
 {
 	struct nvkm_i2c_impl *impl = (void *)nv_oclass(subdev);
 	struct nvkm_i2c *i2c = nvkm_i2c(subdev);
 	struct nvkm_i2c_port *port;
 	u32 hi, lo, rq, tx, e;

 	if (impl->aux_stat) {
 		impl->aux_stat(i2c, &hi, &lo, &rq, &tx);
 		if (hi || lo || rq || tx) {
 			list_for_each_entry(port, &i2c->ports, head) {
 				if (e = 0, port->aux < 0)
 					continue;

 				if (hi & (1 << port->aux)) e |= NVKM_I2C_PLUG;
 				if (lo & (1 << port->aux)) e |= NVKM_I2C_UNPLUG;
 				if (rq & (1 << port->aux)) e |= NVKM_I2C_IRQ;
 				if (tx & (1 << port->aux)) e |= NVKM_I2C_DONE;
 				if (e) {
 					struct nvkm_i2c_ntfy_rep rep = {
 						.mask = e,
 					};
 					nvkm_event_send(&i2c->event, rep.mask,
 							port->index, &rep,
 							sizeof(rep));
 				}
 			}
 		}
 	}
 }

 static const struct nvkm_event_func
 nvkm_i2c_intr_func = {
 	.ctor = nvkm_i2c_intr_ctor,
 	.init = nvkm_i2c_intr_init,
 	.fini = nvkm_i2c_intr_fini,
 };

 int
 _nvkm_i2c_fini(struct nvkm_object *object, bool suspend)
 {
 	struct nvkm_i2c_impl *impl = (void *)nv_oclass(object);
 	struct nvkm_i2c *i2c = (void *)object;
 	struct nvkm_i2c_port *port;
 	u32 mask;
 	int ret;

 	list_for_each_entry(port, &i2c->ports, head) {
 		ret = nv_ofuncs(port)->fini(nv_object(port), suspend);
 		if (ret && suspend)
 			goto fail;
 	}

 	if ((mask = (1 << impl->aux) - 1), impl->aux_stat) {
 		impl->aux_mask(i2c, NVKM_I2C_ANY, mask, 0);
 		impl->aux_stat(i2c, &mask, &mask, &mask, &mask);
 	}

 	return nvkm_subdev_fini(&i2c->base, suspend);
 fail:
 	list_for_each_entry_continue_reverse(port, &i2c->ports, head) {
 		nv_ofuncs(port)->init(nv_object(port));
 	}

 	return ret;
 }

 int
 _nvkm_i2c_init(struct nvkm_object *object)
 {
 	struct nvkm_i2c *i2c = (void *)object;
 	struct nvkm_i2c_port *port;
 	int ret;

 	ret = nvkm_subdev_init(&i2c->base);
 	if (ret == 0) {
 		list_for_each_entry(port, &i2c->ports, head) {
 			ret = nv_ofuncs(port)->init(nv_object(port));
 			if (ret)
 				goto fail;
 		}
 	}

 	return ret;
 fail:
 	list_for_each_entry_continue_reverse(port, &i2c->ports, head) {
 		nv_ofuncs(port)->fini(nv_object(port), false);
 	}

 	return ret;
 }

 void
 _nvkm_i2c_dtor(struct nvkm_object *object)
 {
 	struct nvkm_i2c *i2c = (void *)object;
 	struct nvkm_i2c_port *port, *temp;

 	nvkm_event_fini(&i2c->event);

 	list_for_each_entry_safe(port, temp, &i2c->ports, head) {
 		nvkm_object_ref(NULL, (struct nvkm_object **)&port);
 	}

 	nvkm_subdev_destroy(&i2c->base);
 }

 static struct nvkm_oclass *
 nvkm_i2c_extdev_sclass[] = {
 	nvkm_anx9805_sclass,
 };

 static void
 nvkm_i2c_create_port(struct nvkm_i2c *i2c, int index, u8 type,
 		     struct dcb_i2c_entry *info)
 {
 	const struct nvkm_i2c_impl *impl = (void *)nv_oclass(i2c);
 	struct nvkm_oclass *oclass;
 	struct nvkm_object *parent;
 	struct nvkm_object *object;
 	int ret, pad;

 	if (info->share != DCB_I2C_UNUSED) {
 		pad    = info->share;
 		oclass = impl->pad_s;
 	} else {
 		if (type != DCB_I2C_NVIO_AUX)
 			pad = 0x100 + info->drive;
 		else
 			pad = 0x100 + info->auxch;
 		oclass = impl->pad_x;
 	}

 	ret = nvkm_object_ctor(nv_object(i2c), NULL, oclass,
 			       NULL, pad, &parent);
 	if (ret < 0)
 		return;

 	oclass = impl->sclass;
 	do {
 		ret = -EINVAL;
 		if (oclass->handle == type) {
 			ret = nvkm_object_ctor(parent, NULL, oclass,
 					       info, index, &object);
 		}
 	} while (ret && (++oclass)->handle);

 	nvkm_object_ref(NULL, &parent);
 }

 int
 nvkm_i2c_create_(struct nvkm_object *parent, struct nvkm_object *engine,
 		 struct nvkm_oclass *oclass, int length, void **pobject)
 {
 	struct nvkm_bios *bios = nvkm_bios(parent);
 	struct nvkm_i2c *i2c;
 	struct nvkm_object *object;
 	struct dcb_i2c_entry info;
 	int ret, i, j, index = -1;
 	struct dcb_output outp;
 	u8  ver, hdr;
 	u32 data;

 	ret = nvkm_subdev_create(parent, engine, oclass, 0, "I2C", "i2c", &i2c);
 	*pobject = nv_object(i2c);
 	if (ret)
 		return ret;

 	nv_subdev(i2c)->intr = nvkm_i2c_intr;
 	i2c->find = nvkm_i2c_find;
 	i2c->find_type = nvkm_i2c_find_type;
 	i2c->acquire_pad = nvkm_i2c_acquire_pad;
 	i2c->release_pad = nvkm_i2c_release_pad;
 	i2c->acquire = nvkm_i2c_acquire;
 	i2c->release = nvkm_i2c_release;
 	i2c->identify = nvkm_i2c_identify;
 	init_waitqueue_head(&i2c->wait);
 	INIT_LIST_HEAD(&i2c->ports);

 	while (!dcb_i2c_parse(bios, ++index, &info)) {
 		switch (info.type) {
 		case DCB_I2C_NV04_BIT:
 		case DCB_I2C_NV4E_BIT:
 		case DCB_I2C_NVIO_BIT:
 			nvkm_i2c_create_port(i2c, NV_I2C_PORT(index),
 					     info.type, &info);
 			break;
 		case DCB_I2C_NVIO_AUX:
 			nvkm_i2c_create_port(i2c, NV_I2C_AUX(index),
 					     info.type, &info);
 			break;
 		case DCB_I2C_PMGR:
 			if (info.drive != DCB_I2C_UNUSED) {
 				nvkm_i2c_create_port(i2c, NV_I2C_PORT(index),
 						     DCB_I2C_NVIO_BIT, &info);
 			}
 			if (info.auxch != DCB_I2C_UNUSED) {
 				nvkm_i2c_create_port(i2c, NV_I2C_AUX(index),
 						     DCB_I2C_NVIO_AUX, &info);
 			}
 			break;
 		case DCB_I2C_UNUSED:
 		default:
 			continue;
 		}
 	}

 	/* in addition to the busses specified in the i2c table, there
 	 * may be ddc/aux channels hiding behind external tmds/dp/etc
 	 * transmitters.
 	 */
 	index = NV_I2C_EXT(0);
 	i = -1;
 	while ((data = dcb_outp_parse(bios, ++i, &ver, &hdr, &outp))) {
 		if (!outp.location || !outp.extdev)
 			continue;

 		switch (outp.type) {
 		case DCB_OUTPUT_TMDS:
 			info.type = NV_I2C_TYPE_EXTDDC(outp.extdev);
 			break;
 		case DCB_OUTPUT_DP:
 			info.type = NV_I2C_TYPE_EXTAUX(outp.extdev);
 			break;
 		default:
 			continue;
 		}

 		ret = -ENODEV;
 		j = -1;
 		while (ret && ++j < ARRAY_SIZE(nvkm_i2c_extdev_sclass)) {
 			parent = nv_object(i2c->find(i2c, outp.i2c_index));
 			oclass = nvkm_i2c_extdev_sclass[j];
 			do {
 				if (oclass->handle != info.type)
 					continue;
 				ret = nvkm_object_ctor(parent, NULL, oclass,
 						       NULL, index++, &object);
 			} while (ret && (++oclass)->handle);
 		}
 	}

 	ret = nvkm_event_init(&nvkm_i2c_intr_func, 4, index, &i2c->event);
 	if (ret)
 		return ret;

 	return 0;
 }

 int
 _nvkm_i2c_ctor(struct nvkm_object *parent, struct nvkm_object *engine,
 	       struct nvkm_oclass *oclass, void *data, u32 size,
 	       struct nvkm_object **pobject)
 {
 	struct nvkm_i2c *i2c;
 	int ret;

 	ret = nvkm_i2c_create(parent, engine, oclass, &i2c);
 	*pobject = nv_object(i2c);
 	if (ret)
 		return ret;

 	return 0;
 }
	/*
	* Copyright 2013 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 "priv.h"
	#include "pad.h"

	#include <core/device.h>
	#include <core/notify.h>
	#include <core/option.h>
	#include <subdev/bios.h>
	#include <subdev/bios/dcb.h>

	/******************************************************************************
	* interface to linux i2c bit-banging algorithm
	*****************************************************************************/

	#ifdef CONFIG_NOUVEAU_I2C_INTERNAL_DEFAULT
	#define CSTMSEL true
	#else
	#define CSTMSEL false
	#endif

	static int
	nvkm_i2c_pre_xfer(struct i2c_adapter *adap)
	{
	struct i2c_algo_bit_data *bit = adap->algo_data;
	struct nvkm_i2c_port *port = bit->data;
	return nvkm_i2c(port)->acquire(port, bit->timeout);
	}

	static void
	nvkm_i2c_post_xfer(struct i2c_adapter *adap)
	{
	struct i2c_algo_bit_data *bit = adap->algo_data;
	struct nvkm_i2c_port *port = bit->data;
	return nvkm_i2c(port)->release(port);
	}

	static void
	nvkm_i2c_setscl(void *data, int state)
	{
	struct nvkm_i2c_port *port = data;
	port->func->drive_scl(port, state);
	}

	static void
	nvkm_i2c_setsda(void *data, int state)
	{
	struct nvkm_i2c_port *port = data;
	port->func->drive_sda(port, state);
	}

	static int
	nvkm_i2c_getscl(void *data)
	{
	struct nvkm_i2c_port *port = data;
	return port->func->sense_scl(port);
	}

	static int
	nvkm_i2c_getsda(void *data)
	{
	struct nvkm_i2c_port *port = data;
	return port->func->sense_sda(port);
	}

	/******************************************************************************
	* base i2c "port" class implementation
	*****************************************************************************/

	int
	_nvkm_i2c_port_fini(struct nvkm_object *object, bool suspend)
	{
	struct nvkm_i2c_port port = (void )object;
	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
	nv_ofuncs(pad)->fini(nv_object(pad), suspend);
	return nvkm_object_fini(&port->base, suspend);
	}

	void
	_nvkm_i2c_port_dtor(struct nvkm_object *object)
	{
	struct nvkm_i2c_port port = (void )object;
	i2c_del_adapter(&port->adapter);
	nvkm_object_destroy(&port->base);
	}

	int
	nvkm_i2c_port_create_(struct nvkm_object parent, struct nvkm_object engine,
	struct nvkm_oclass *oclass, u8 index,
	const struct i2c_algorithm *algo,
	const struct nvkm_i2c_func *func,
	int size, void **pobject)
	{
	struct nvkm_device *device = nv_device(parent);
	struct nvkm_i2c *i2c = nvkm_i2c(parent);
	struct nvkm_i2c_port *port;
	int ret;

	ret = nvkm_object_create_(parent, engine, oclass, 0, size, pobject);
	port = *pobject;
	if (ret)
	return ret;

	snprintf(port->adapter.name, sizeof(port->adapter.name),
	"nvkm-%s-%d", device->name, index);
	port->adapter.owner = THIS_MODULE;
	port->adapter.dev.parent = nv_device_base(device);
	port->index = index;
	port->aux = -1;
	port->func = func;
	mutex_init(&port->mutex);

	if ( algo == &nvkm_i2c_bit_algo &&
	!nvkm_boolopt(device->cfgopt, "NvI2C", CSTMSEL)) {
	struct i2c_algo_bit_data *bit;

	bit = kzalloc(sizeof(*bit), GFP_KERNEL);
	if (!bit)
	return -ENOMEM;

	bit->udelay = 10;
	bit->timeout = usecs_to_jiffies(2200);
	bit->data = port;
	bit->pre_xfer = nvkm_i2c_pre_xfer;
	bit->post_xfer = nvkm_i2c_post_xfer;
	bit->setsda = nvkm_i2c_setsda;
	bit->setscl = nvkm_i2c_setscl;
	bit->getsda = nvkm_i2c_getsda;
	bit->getscl = nvkm_i2c_getscl;

	port->adapter.algo_data = bit;
	ret = i2c_bit_add_bus(&port->adapter);
	} else {
	port->adapter.algo_data = port;
	port->adapter.algo = algo;
	ret = i2c_add_adapter(&port->adapter);
	}

	if (ret == 0)
	list_add_tail(&port->head, &i2c->ports);
	return ret;
	}

	/******************************************************************************
	* base i2c subdev class implementation
	*****************************************************************************/

	static struct nvkm_i2c_port *
	nvkm_i2c_find(struct nvkm_i2c *i2c, u8 index)
	{
	struct nvkm_bios *bios = nvkm_bios(i2c);
	struct nvkm_i2c_port *port;

	if (index == NV_I2C_DEFAULT(0) \|\|
	index == NV_I2C_DEFAULT(1)) {
	u8 ver, hdr, cnt, len;
	u16 i2c = dcb_i2c_table(bios, &ver, &hdr, &cnt, &len);
	if (i2c && ver >= 0x30) {
	u8 auxidx = nv_ro08(bios, i2c + 4);
	if (index == NV_I2C_DEFAULT(0))
	index = (auxidx & 0x0f) >> 0;
	else
	index = (auxidx & 0xf0) >> 4;
	} else {
	index = 2;
	}
	}

	list_for_each_entry(port, &i2c->ports, head) {
	if (port->index == index)
	return port;
	}

	return NULL;
	}

	static struct nvkm_i2c_port *
	nvkm_i2c_find_type(struct nvkm_i2c *i2c, u16 type)
	{
	struct nvkm_i2c_port *port;

	list_for_each_entry(port, &i2c->ports, head) {
	if (nv_hclass(port) == type)
	return port;
	}

	return NULL;
	}

	static void
	nvkm_i2c_release_pad(struct nvkm_i2c_port *port)
	{
	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);
	struct nvkm_i2c *i2c = nvkm_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
	nvkm_i2c_try_acquire_pad(struct nvkm_i2c_port *port)
	{
	struct nvkm_i2c_pad *pad = nvkm_i2c_pad(port);

	if (atomic_add_return(1, &nv_object(pad)->usecount) != 1) {
	struct nvkm_object owner = (void )pad->port;
	do {
	if (owner == (void *)port)
	return 0;
	owner = owner->parent;
	} while(owner);
	nvkm_i2c_release_pad(port);
	return -EBUSY;
	}

	pad->next = port;
	nv_ofuncs(pad)->init(nv_object(pad));
	return 0;
	}

	static int
	nvkm_i2c_acquire_pad(struct nvkm_i2c_port *port, unsigned long timeout)
	{
	struct nvkm_i2c *i2c = nvkm_i2c(port);

	if (timeout) {
	if (wait_event_timeout(i2c->wait,
	nvkm_i2c_try_acquire_pad(port) == 0,
	timeout) == 0)
	return -EBUSY;
	} else {
	wait_event(i2c->wait, nvkm_i2c_try_acquire_pad(port) == 0);
	}

	return 0;
	}

	static void
	nvkm_i2c_release(struct nvkm_i2c_port *port)
	__releases(pad->mutex)
	{
	nvkm_i2c(port)->release_pad(port);
	mutex_unlock(&port->mutex);
	}

	static int
	nvkm_i2c_acquire(struct nvkm_i2c_port *port, unsigned long timeout)
	__acquires(pad->mutex)
	{
	int ret;
	mutex_lock(&port->mutex);
	if ((ret = nvkm_i2c(port)->acquire_pad(port, timeout)))
	mutex_unlock(&port->mutex);
	return ret;
	}

	static int
	nvkm_i2c_identify(struct nvkm_i2c i2c, int index, const char what,
	struct nvkm_i2c_board_info *info,
	bool (match)(struct nvkm_i2c_port ,
	struct i2c_board_info , void ), void *data)
	{
	struct nvkm_i2c_port *port = nvkm_i2c_find(i2c, index);
	int i;

	if (!port) {
	nv_debug(i2c, "no bus when probing %s on %d\n", what, index);
	return -ENODEV;
	}

	nv_debug(i2c, "probing %ss on bus: %d\n", what, port->index);
	for (i = 0; info[i].dev.addr; i++) {
	u8 orig_udelay = 0;

	if ((port->adapter.algo == &i2c_bit_algo) &&
	(info[i].udelay != 0)) {
	struct i2c_algo_bit_data *algo = port->adapter.algo_data;
	nv_debug(i2c, "using custom udelay %d instead of %d\n",
	info[i].udelay, algo->udelay);
	orig_udelay = algo->udelay;
	algo->udelay = info[i].udelay;
	}

	if (nv_probe_i2c(port, info[i].dev.addr) &&
	(!match \|\| match(port, &info[i].dev, data))) {
	nv_info(i2c, "detected %s: %s\n", what,
	info[i].dev.type);
	return i;
	}

	if (orig_udelay) {
	struct i2c_algo_bit_data *algo = port->adapter.algo_data;
	algo->udelay = orig_udelay;
	}
	}

	nv_debug(i2c, "no devices found.\n");
	return -ENODEV;
	}

	static void
	nvkm_i2c_intr_fini(struct nvkm_event *event, int type, int index)
	{
	struct nvkm_i2c i2c = container_of(event, typeof(i2c), event);
	struct nvkm_i2c_port *port = i2c->find(i2c, index);
	const struct nvkm_i2c_impl impl = (void )nv_object(i2c)->oclass;
	if (port && port->aux >= 0)
	impl->aux_mask(i2c, type, 1 << port->aux, 0);
	}

	static void
	nvkm_i2c_intr_init(struct nvkm_event *event, int type, int index)
	{
	struct nvkm_i2c i2c = container_of(event, typeof(i2c), event);
	struct nvkm_i2c_port *port = i2c->find(i2c, index);
	const struct nvkm_i2c_impl impl = (void )nv_object(i2c)->oclass;
	if (port && port->aux >= 0)
	impl->aux_mask(i2c, type, 1 << port->aux, 1 << port->aux);
	}

	static int
	nvkm_i2c_intr_ctor(struct nvkm_object object, void data, u32 size,
	struct nvkm_notify *notify)
	{
	struct nvkm_i2c_ntfy_req *req = data;
	if (!WARN_ON(size != sizeof(*req))) {
	notify->size = sizeof(struct nvkm_i2c_ntfy_rep);
	notify->types = req->mask;
	notify->index = req->port;
	return 0;
	}
	return -EINVAL;
	}

	static void
	nvkm_i2c_intr(struct nvkm_subdev *subdev)
	{
	struct nvkm_i2c_impl impl = (void )nv_oclass(subdev);
	struct nvkm_i2c *i2c = nvkm_i2c(subdev);
	struct nvkm_i2c_port *port;
	u32 hi, lo, rq, tx, e;

	if (impl->aux_stat) {
	impl->aux_stat(i2c, &hi, &lo, &rq, &tx);
	if (hi \|\| lo \|\| rq \|\| tx) {
	list_for_each_entry(port, &i2c->ports, head) {
	if (e = 0, port->aux < 0)
	continue;

	if (hi & (1 << port->aux)) e \|= NVKM_I2C_PLUG;
	if (lo & (1 << port->aux)) e \|= NVKM_I2C_UNPLUG;
	if (rq & (1 << port->aux)) e \|= NVKM_I2C_IRQ;
	if (tx & (1 << port->aux)) e \|= NVKM_I2C_DONE;
	if (e) {
	struct nvkm_i2c_ntfy_rep rep = {
	.mask = e,
	};
	nvkm_event_send(&i2c->event, rep.mask,
	port->index, &rep,
	sizeof(rep));
	}
	}
	}
	}
	}

	static const struct nvkm_event_func
	nvkm_i2c_intr_func = {
	.ctor = nvkm_i2c_intr_ctor,
	.init = nvkm_i2c_intr_init,
	.fini = nvkm_i2c_intr_fini,
	};

	int
	_nvkm_i2c_fini(struct nvkm_object *object, bool suspend)
	{
	struct nvkm_i2c_impl impl = (void )nv_oclass(object);
	struct nvkm_i2c i2c = (void )object;
	struct nvkm_i2c_port *port;
	u32 mask;
	int ret;

	list_for_each_entry(port, &i2c->ports, head) {
	ret = nv_ofuncs(port)->fini(nv_object(port), suspend);
	if (ret && suspend)
	goto fail;
	}

	if ((mask = (1 << impl->aux) - 1), impl->aux_stat) {
	impl->aux_mask(i2c, NVKM_I2C_ANY, mask, 0);
	impl->aux_stat(i2c, &mask, &mask, &mask, &mask);
	}

	return nvkm_subdev_fini(&i2c->base, suspend);
	fail:
	list_for_each_entry_continue_reverse(port, &i2c->ports, head) {
	nv_ofuncs(port)->init(nv_object(port));
	}

	return ret;
	}

	int
	_nvkm_i2c_init(struct nvkm_object *object)
	{
	struct nvkm_i2c i2c = (void )object;
	struct nvkm_i2c_port *port;
	int ret;

	ret = nvkm_subdev_init(&i2c->base);
	if (ret == 0) {
	list_for_each_entry(port, &i2c->ports, head) {
	ret = nv_ofuncs(port)->init(nv_object(port));
	if (ret)
	goto fail;
	}
	}

	return ret;
	fail:
	list_for_each_entry_continue_reverse(port, &i2c->ports, head) {
	nv_ofuncs(port)->fini(nv_object(port), false);
	}

	return ret;
	}

	void
	_nvkm_i2c_dtor(struct nvkm_object *object)
	{
	struct nvkm_i2c i2c = (void )object;
	struct nvkm_i2c_port port, temp;

	nvkm_event_fini(&i2c->event);

	list_for_each_entry_safe(port, temp, &i2c->ports, head) {
	nvkm_object_ref(NULL, (struct nvkm_object **)&port);
	}

	nvkm_subdev_destroy(&i2c->base);
	}

	static struct nvkm_oclass *
	nvkm_i2c_extdev_sclass[] = {
	nvkm_anx9805_sclass,
	};

	static void
	nvkm_i2c_create_port(struct nvkm_i2c *i2c, int index, u8 type,
	struct dcb_i2c_entry *info)
	{
	const struct nvkm_i2c_impl impl = (void )nv_oclass(i2c);
	struct nvkm_oclass *oclass;
	struct nvkm_object *parent;
	struct nvkm_object *object;
	int ret, pad;

	if (info->share != DCB_I2C_UNUSED) {
	pad = info->share;
	oclass = impl->pad_s;
	} else {
	if (type != DCB_I2C_NVIO_AUX)
	pad = 0x100 + info->drive;
	else
	pad = 0x100 + info->auxch;
	oclass = impl->pad_x;
	}

	ret = nvkm_object_ctor(nv_object(i2c), NULL, oclass,
	NULL, pad, &parent);
	if (ret < 0)
	return;

	oclass = impl->sclass;
	do {
	ret = -EINVAL;
	if (oclass->handle == type) {
	ret = nvkm_object_ctor(parent, NULL, oclass,
	info, index, &object);
	}
	} while (ret && (++oclass)->handle);

	nvkm_object_ref(NULL, &parent);
	}

	int
	nvkm_i2c_create_(struct nvkm_object parent, struct nvkm_object engine,
	struct nvkm_oclass oclass, int length, void *pobject)
	{
	struct nvkm_bios *bios = nvkm_bios(parent);
	struct nvkm_i2c *i2c;
	struct nvkm_object *object;
	struct dcb_i2c_entry info;
	int ret, i, j, index = -1;
	struct dcb_output outp;
	u8 ver, hdr;
	u32 data;

	ret = nvkm_subdev_create(parent, engine, oclass, 0, "I2C", "i2c", &i2c);
	*pobject = nv_object(i2c);
	if (ret)
	return ret;

	nv_subdev(i2c)->intr = nvkm_i2c_intr;
	i2c->find = nvkm_i2c_find;
	i2c->find_type = nvkm_i2c_find_type;
	i2c->acquire_pad = nvkm_i2c_acquire_pad;
	i2c->release_pad = nvkm_i2c_release_pad;
	i2c->acquire = nvkm_i2c_acquire;
	i2c->release = nvkm_i2c_release;
	i2c->identify = nvkm_i2c_identify;
	init_waitqueue_head(&i2c->wait);
	INIT_LIST_HEAD(&i2c->ports);

	while (!dcb_i2c_parse(bios, ++index, &info)) {
	switch (info.type) {
	case DCB_I2C_NV04_BIT:
	case DCB_I2C_NV4E_BIT:
	case DCB_I2C_NVIO_BIT:
	nvkm_i2c_create_port(i2c, NV_I2C_PORT(index),
	info.type, &info);
	break;
	case DCB_I2C_NVIO_AUX:
	nvkm_i2c_create_port(i2c, NV_I2C_AUX(index),
	info.type, &info);
	break;
	case DCB_I2C_PMGR:
	if (info.drive != DCB_I2C_UNUSED) {
	nvkm_i2c_create_port(i2c, NV_I2C_PORT(index),
	DCB_I2C_NVIO_BIT, &info);
	}
	if (info.auxch != DCB_I2C_UNUSED) {
	nvkm_i2c_create_port(i2c, NV_I2C_AUX(index),
	DCB_I2C_NVIO_AUX, &info);
	}
	break;
	case DCB_I2C_UNUSED:
	default:
	continue;
	}
	}

	/* in addition to the busses specified in the i2c table, there
	* may be ddc/aux channels hiding behind external tmds/dp/etc
	* transmitters.
	*/
	index = NV_I2C_EXT(0);
	i = -1;
	while ((data = dcb_outp_parse(bios, ++i, &ver, &hdr, &outp))) {
	if (!outp.location \|\| !outp.extdev)
	continue;

	switch (outp.type) {
	case DCB_OUTPUT_TMDS:
	info.type = NV_I2C_TYPE_EXTDDC(outp.extdev);
	break;
	case DCB_OUTPUT_DP:
	info.type = NV_I2C_TYPE_EXTAUX(outp.extdev);
	break;
	default:
	continue;
	}

	ret = -ENODEV;
	j = -1;
	while (ret && ++j < ARRAY_SIZE(nvkm_i2c_extdev_sclass)) {
	parent = nv_object(i2c->find(i2c, outp.i2c_index));
	oclass = nvkm_i2c_extdev_sclass[j];
	do {
	if (oclass->handle != info.type)
	continue;
	ret = nvkm_object_ctor(parent, NULL, oclass,
	NULL, index++, &object);
	} while (ret && (++oclass)->handle);
	}
	}

	ret = nvkm_event_init(&nvkm_i2c_intr_func, 4, index, &i2c->event);
	if (ret)
	return ret;

	return 0;
	}

	int
	_nvkm_i2c_ctor(struct nvkm_object parent, struct nvkm_object engine,
	struct nvkm_oclass oclass, void data, u32 size,
	struct nvkm_object **pobject)
	{
	struct nvkm_i2c *i2c;
	int ret;

	ret = nvkm_i2c_create(parent, engine, oclass, &i2c);
	*pobject = nv_object(i2c);
	if (ret)
	return ret;

	return 0;
	}