text: /*
   * TI OMAP4 ISS V4L2 Driver
   *
   * Copyright (C) 2012, Texas Instruments
   *
   * Author: Sergio Aguirre <sergio.a.aguirre@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  #include <linux/clk.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <linux/dma-mapping.h>
  #include <linux/i2c.h>
  #include <linux/interrupt.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/sched.h>
  #include <linux/vmalloc.h>
  
  #include <media/v4l2-common.h>
  #include <media/v4l2-device.h>
  #include <media/v4l2-ctrls.h>
  
  #include "iss.h"
  #include "iss_regs.h"
  
  #define ISS_PRINT_REGISTER(iss, name)\
  	dev_dbg(iss->dev, "###ISS " #name "=0x%08x\n", \
  		iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_##name))
  
  static void iss_print_status(struct iss_device *iss)
  {
  	dev_dbg(iss->dev, "-------------ISS HL Register dump-------------\n");
  
  	ISS_PRINT_REGISTER(iss, HL_REVISION);
  	ISS_PRINT_REGISTER(iss, HL_SYSCONFIG);
  	ISS_PRINT_REGISTER(iss, HL_IRQSTATUS(5));
  	ISS_PRINT_REGISTER(iss, HL_IRQENABLE_SET(5));
  	ISS_PRINT_REGISTER(iss, HL_IRQENABLE_CLR(5));
  	ISS_PRINT_REGISTER(iss, CTRL);
  	ISS_PRINT_REGISTER(iss, CLKCTRL);
  	ISS_PRINT_REGISTER(iss, CLKSTAT);
  
  	dev_dbg(iss->dev, "-----------------------------------------------\n");
  }
  
  /*
   * omap4iss_flush - Post pending L3 bus writes by doing a register readback
   * @iss: OMAP4 ISS device
   *
   * In order to force posting of pending writes, we need to write and
   * readback the same register, in this case the revision register.
   *
   * See this link for reference:
   *   http://www.mail-archive.com/linux-omap@vger.kernel.org/msg08149.html
   */
  void omap4iss_flush(struct iss_device *iss)
  {
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_HL_REVISION, 0);
  	iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_HL_REVISION);
  }
  
  /*
   * iss_isp_enable_interrupts - Enable ISS ISP interrupts.
   * @iss: OMAP4 ISS device
   */
  static void omap4iss_isp_enable_interrupts(struct iss_device *iss)
  {
  	static const u32 isp_irq = ISP5_IRQ_OCP_ERR |
  				   ISP5_IRQ_RSZ_FIFO_IN_BLK_ERR |
  				   ISP5_IRQ_RSZ_FIFO_OVF |
  				   ISP5_IRQ_RSZ_INT_DMA |
  				   ISP5_IRQ_ISIF_INT(0);
  
  	/* Enable ISP interrupts */
  	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_IRQSTATUS(0), isp_irq);
  	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_IRQENABLE_SET(0),
  		      isp_irq);
  }
  
  /*
   * iss_isp_disable_interrupts - Disable ISS interrupts.
   * @iss: OMAP4 ISS device
   */
  static void omap4iss_isp_disable_interrupts(struct iss_device *iss)
  {
  	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_IRQENABLE_CLR(0), ~0);
  }
  
  /*
   * iss_enable_interrupts - Enable ISS interrupts.
   * @iss: OMAP4 ISS device
   */
  static void iss_enable_interrupts(struct iss_device *iss)
  {
  	static const u32 hl_irq = ISS_HL_IRQ_CSIA | ISS_HL_IRQ_CSIB
  				| ISS_HL_IRQ_ISP(0);
  
  	/* Enable HL interrupts */
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_HL_IRQSTATUS(5), hl_irq);
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_HL_IRQENABLE_SET(5), hl_irq);
  
  	if (iss->regs[OMAP4_ISS_MEM_ISP_SYS1])
  		omap4iss_isp_enable_interrupts(iss);
  }
  
  /*
   * iss_disable_interrupts - Disable ISS interrupts.
   * @iss: OMAP4 ISS device
   */
  static void iss_disable_interrupts(struct iss_device *iss)
  {
  	if (iss->regs[OMAP4_ISS_MEM_ISP_SYS1])
  		omap4iss_isp_disable_interrupts(iss);
  
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_HL_IRQENABLE_CLR(5), ~0);
  }
  
  int omap4iss_get_external_info(struct iss_pipeline *pipe,
  			       struct media_link *link)
  {
  	struct iss_device *iss =
  		container_of(pipe, struct iss_video, pipe)->iss;
  	struct v4l2_subdev_format fmt;
  	struct v4l2_ctrl *ctrl;
  	int ret;
  
  	if (!pipe->external)
  		return 0;
  
  	if (pipe->external_rate)
  		return 0;
  
  	memset(&fmt, 0, sizeof(fmt));
  
  	fmt.pad = link->source->index;
  	fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
  	ret = v4l2_subdev_call(media_entity_to_v4l2_subdev(link->sink->entity),
  			       pad, get_fmt, NULL, &fmt);
  	if (ret < 0)
  		return -EPIPE;
  
  	pipe->external_bpp = omap4iss_video_format_info(fmt.format.code)->bpp;
  
  	ctrl = v4l2_ctrl_find(pipe->external->ctrl_handler,
  			      V4L2_CID_PIXEL_RATE);
  	if (ctrl == NULL) {
  		dev_warn(iss->dev, "no pixel rate control in subdev %s\n",
  			 pipe->external->name);
  		return -EPIPE;
  	}
  
  	pipe->external_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
  
  	return 0;
  }
  
  /*
   * Configure the bridge. Valid inputs are
   *
   * IPIPEIF_INPUT_CSI2A: CSI2a receiver
   * IPIPEIF_INPUT_CSI2B: CSI2b receiver
   *
   * The bridge and lane shifter are configured according to the selected input
   * and the ISP platform data.
   */
  void omap4iss_configure_bridge(struct iss_device *iss,
  			       enum ipipeif_input_entity input)
  {
  	u32 issctrl_val;
  	u32 isp5ctrl_val;
  
  	issctrl_val = iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_CTRL);
  	issctrl_val &= ~ISS_CTRL_INPUT_SEL_MASK;
  	issctrl_val &= ~ISS_CTRL_CLK_DIV_MASK;
  
  	isp5ctrl_val = iss_reg_read(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_CTRL);
  
  	switch (input) {
  	case IPIPEIF_INPUT_CSI2A:
  		issctrl_val |= ISS_CTRL_INPUT_SEL_CSI2A;
  		break;
  
  	case IPIPEIF_INPUT_CSI2B:
  		issctrl_val |= ISS_CTRL_INPUT_SEL_CSI2B;
  		break;
  
  	default:
  		return;
  	}
  
  	issctrl_val |= ISS_CTRL_SYNC_DETECT_VS_RAISING;
  
  	isp5ctrl_val |= ISP5_CTRL_VD_PULSE_EXT | ISP5_CTRL_PSYNC_CLK_SEL |
  			ISP5_CTRL_SYNC_ENABLE;
  
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_CTRL, issctrl_val);
  	iss_reg_write(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_CTRL, isp5ctrl_val);
  }
  
  #ifdef ISS_ISR_DEBUG
  static void iss_isr_dbg(struct iss_device *iss, u32 irqstatus)
  {
  	static const char * const name[] = {
  		"ISP_0",
  		"ISP_1",
  		"ISP_2",
  		"ISP_3",
  		"CSIA",
  		"CSIB",
  		"CCP2_0",
  		"CCP2_1",
  		"CCP2_2",
  		"CCP2_3",
  		"CBUFF",
  		"BTE",
  		"SIMCOP_0",
  		"SIMCOP_1",
  		"SIMCOP_2",
  		"SIMCOP_3",
  		"CCP2_8",
  		"HS_VS",
  		"18",
  		"19",
  		"20",
  		"21",
  		"22",
  		"23",
  		"24",
  		"25",
  		"26",
  		"27",
  		"28",
  		"29",
  		"30",
  		"31",
  	};
  	unsigned int i;
  
  	dev_dbg(iss->dev, "ISS IRQ: ");
  
  	for (i = 0; i < ARRAY_SIZE(name); i++) {
  		if ((1 << i) & irqstatus)
  			pr_cont("%s ", name[i]);
  	}
  	pr_cont("\n");
  }
  
  static void iss_isp_isr_dbg(struct iss_device *iss, u32 irqstatus)
  {
  	static const char * const name[] = {
  		"ISIF_0",
  		"ISIF_1",
  		"ISIF_2",
  		"ISIF_3",
  		"IPIPEREQ",
  		"IPIPELAST_PIX",
  		"IPIPEDMA",
  		"IPIPEBSC",
  		"IPIPEHST",
  		"IPIPEIF",
  		"AEW",
  		"AF",
  		"H3A",
  		"RSZ_REG",
  		"RSZ_LAST_PIX",
  		"RSZ_DMA",
  		"RSZ_CYC_RZA",
  		"RSZ_CYC_RZB",
  		"RSZ_FIFO_OVF",
  		"RSZ_FIFO_IN_BLK_ERR",
  		"20",
  		"21",
  		"RSZ_EOF0",
  		"RSZ_EOF1",
  		"H3A_EOF",
  		"IPIPE_EOF",
  		"26",
  		"IPIPE_DPC_INI",
  		"IPIPE_DPC_RNEW0",
  		"IPIPE_DPC_RNEW1",
  		"30",
  		"OCP_ERR",
  	};
  	unsigned int i;
  
  	dev_dbg(iss->dev, "ISP IRQ: ");
  
  	for (i = 0; i < ARRAY_SIZE(name); i++) {
  		if ((1 << i) & irqstatus)
  			pr_cont("%s ", name[i]);
  	}
  	pr_cont("\n");
  }
  #endif
  
  /*
   * iss_isr - Interrupt Service Routine for ISS module.
   * @irq: Not used currently.
   * @_iss: Pointer to the OMAP4 ISS device
   *
   * Handles the corresponding callback if plugged in.
   *
   * Returns IRQ_HANDLED when IRQ was correctly handled, or IRQ_NONE when the
   * IRQ wasn't handled.
   */
  static irqreturn_t iss_isr(int irq, void *_iss)
  {
  	static const u32 ipipeif_events = ISP5_IRQ_IPIPEIF_IRQ |
  					  ISP5_IRQ_ISIF_INT(0);
  	static const u32 resizer_events = ISP5_IRQ_RSZ_FIFO_IN_BLK_ERR |
  					  ISP5_IRQ_RSZ_FIFO_OVF |
  					  ISP5_IRQ_RSZ_INT_DMA;
  	struct iss_device *iss = _iss;
  	u32 irqstatus;
  
  	irqstatus = iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_HL_IRQSTATUS(5));
  	iss_reg_write(iss, OMAP4_ISS_MEM_TOP, ISS_HL_IRQSTATUS(5), irqstatus);
  
  	if (irqstatus & ISS_HL_IRQ_CSIA)
  		omap4iss_csi2_isr(&iss->csi2a);
  
  	if (irqstatus & ISS_HL_IRQ_CSIB)
  		omap4iss_csi2_isr(&iss->csi2b);
  
  	if (irqstatus & ISS_HL_IRQ_ISP(0)) {
  		u32 isp_irqstatus = iss_reg_read(iss, OMAP4_ISS_MEM_ISP_SYS1,
  						 ISP5_IRQSTATUS(0));
  		iss_reg_write(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_IRQSTATUS(0),
  			      isp_irqstatus);
  
  		if (isp_irqstatus & ISP5_IRQ_OCP_ERR)
  			dev_dbg(iss->dev, "ISP5 OCP Error!\n");
  
  		if (isp_irqstatus & ipipeif_events) {
  			omap4iss_ipipeif_isr(&iss->ipipeif,
  					     isp_irqstatus & ipipeif_events);
  		}
  
  		if (isp_irqstatus & resizer_events)
  			omap4iss_resizer_isr(&iss->resizer,
  					     isp_irqstatus & resizer_events);
  
  #ifdef ISS_ISR_DEBUG
  		iss_isp_isr_dbg(iss, isp_irqstatus);
  #endif
  	}
  
  	omap4iss_flush(iss);
  
  #ifdef ISS_ISR_DEBUG
  	iss_isr_dbg(iss, irqstatus);
  #endif
  
  	return IRQ_HANDLED;
  }
  
  /* -----------------------------------------------------------------------------
   * Pipeline power management
   *
   * Entities must be powered up when part of a pipeline that contains at least
   * one open video device node.
   *
   * To achieve this use the entity use_count field to track the number of users.
   * For entities corresponding to video device nodes the use_count field stores
   * the users count of the node. For entities corresponding to subdevs the
   * use_count field stores the total number of users of all video device nodes
   * in the pipeline.
   *
   * The omap4iss_pipeline_pm_use() function must be called in the open() and
   * close() handlers of video device nodes. It increments or decrements the use
   * count of all subdev entities in the pipeline.
   *
   * To react to link management on powered pipelines, the link setup notification
   * callback updates the use count of all entities in the source and sink sides
   * of the link.
   */
  
  /*
   * iss_pipeline_pm_use_count - Count the number of users of a pipeline
   * @entity: The entity
   *
   * Return the total number of users of all video device nodes in the pipeline.
   */
  static int iss_pipeline_pm_use_count(struct media_entity *entity)
  {
  	struct media_entity_graph graph;
  	int use = 0;
  
  	media_entity_graph_walk_start(&graph, entity);
  
  	while ((entity = media_entity_graph_walk_next(&graph))) {
  		if (media_entity_type(entity) == MEDIA_ENT_T_DEVNODE)
  			use += entity->use_count;
  	}
  
  	return use;
  }
  
  /*
   * iss_pipeline_pm_power_one - Apply power change to an entity
   * @entity: The entity
   * @change: Use count change
   *
   * Change the entity use count by @change. If the entity is a subdev update its
   * power state by calling the core::s_power operation when the use count goes
   * from 0 to != 0 or from != 0 to 0.
   *
   * Return 0 on success or a negative error code on failure.
   */
  static int iss_pipeline_pm_power_one(struct media_entity *entity, int change)
  {
  	struct v4l2_subdev *subdev;
  
  	subdev = media_entity_type(entity) == MEDIA_ENT_T_V4L2_SUBDEV
  	       ? media_entity_to_v4l2_subdev(entity) : NULL;
  
  	if (entity->use_count == 0 && change > 0 && subdev != NULL) {
  		int ret;
  
  		ret = v4l2_subdev_call(subdev, core, s_power, 1);
  		if (ret < 0 && ret != -ENOIOCTLCMD)
  			return ret;
  	}
  
  	entity->use_count += change;
  	WARN_ON(entity->use_count < 0);
  
  	if (entity->use_count == 0 && change < 0 && subdev != NULL)
  		v4l2_subdev_call(subdev, core, s_power, 0);
  
  	return 0;
  }
  
  /*
   * iss_pipeline_pm_power - Apply power change to all entities in a pipeline
   * @entity: The entity
   * @change: Use count change
   *
   * Walk the pipeline to update the use count and the power state of all non-node
   * entities.
   *
   * Return 0 on success or a negative error code on failure.
   */
  static int iss_pipeline_pm_power(struct media_entity *entity, int change)
  {
  	struct media_entity_graph graph;
  	struct media_entity *first = entity;
  	int ret = 0;
  
  	if (!change)
  		return 0;
  
  	media_entity_graph_walk_start(&graph, entity);
  
  	while (!ret && (entity = media_entity_graph_walk_next(&graph)))
  		if (media_entity_type(entity) != MEDIA_ENT_T_DEVNODE)
  			ret = iss_pipeline_pm_power_one(entity, change);
  
  	if (!ret)
  		return 0;
  
  	media_entity_graph_walk_start(&graph, first);
  
  	while ((first = media_entity_graph_walk_next(&graph))
  	       && first != entity)
  		if (media_entity_type(first) != MEDIA_ENT_T_DEVNODE)
  			iss_pipeline_pm_power_one(first, -change);
  
  	return ret;
  }
  
  /*
   * omap4iss_pipeline_pm_use - Update the use count of an entity
   * @entity: The entity
   * @use: Use (1) or stop using (0) the entity
   *
   * Update the use count of all entities in the pipeline and power entities on or
   * off accordingly.
   *
   * Return 0 on success or a negative error code on failure. Powering entities
   * off is assumed to never fail. No failure can occur when the use parameter is
   * set to 0.
   */
  int omap4iss_pipeline_pm_use(struct media_entity *entity, int use)
  {
  	int change = use ? 1 : -1;
  	int ret;
  
  	mutex_lock(&entity->parent->graph_mutex);
  
  	/* Apply use count to node. */
  	entity->use_count += change;
  	WARN_ON(entity->use_count < 0);
  
  	/* Apply power change to connected non-nodes. */
  	ret = iss_pipeline_pm_power(entity, change);
  	if (ret < 0)
  		entity->use_count -= change;
  
  	mutex_unlock(&entity->parent->graph_mutex);
  
  	return ret;
  }
  
  /*
   * iss_pipeline_link_notify - Link management notification callback
   * @link: The link
   * @flags: New link flags that will be applied
   *
   * React to link management on powered pipelines by updating the use count of
   * all entities in the source and sink sides of the link. Entities are powered
   * on or off accordingly.
   *
   * Return 0 on success or a negative error code on failure. Powering entities
   * off is assumed to never fail. This function will not fail for disconnection
   * events.
   */
  static int iss_pipeline_link_notify(struct media_link *link, u32 flags,
  				    unsigned int notification)
  {
  	struct media_entity *source = link->source->entity;
  	struct media_entity *sink = link->sink->entity;
  	int source_use = iss_pipeline_pm_use_count(source);
  	int sink_use = iss_pipeline_pm_use_count(sink);
  	int ret;
  
  	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
  	    !(link->flags & MEDIA_LNK_FL_ENABLED)) {
  		/* Powering off entities is assumed to never fail. */
  		iss_pipeline_pm_power(source, -sink_use);
  		iss_pipeline_pm_power(sink, -source_use);
  		return 0;
  	}
  
  	if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
  		(flags & MEDIA_LNK_FL_ENABLED)) {
  		ret = iss_pipeline_pm_power(source, sink_use);
  		if (ret < 0)
  			return ret;
  
  		ret = iss_pipeline_pm_power(sink, source_use);
  		if (ret < 0)
  			iss_pipeline_pm_power(source, -sink_use);
  
  		return ret;
  	}
  
  	return 0;
  }
  
  /* -----------------------------------------------------------------------------
   * Pipeline stream management
   */
  
  /*
   * iss_pipeline_disable - Disable streaming on a pipeline
   * @pipe: ISS pipeline
   * @until: entity at which to stop pipeline walk
   *
   * Walk the entities chain starting at the pipeline output video node and stop
   * all modules in the chain. Wait synchronously for the modules to be stopped if
   * necessary.
   *
   * If the until argument isn't NULL, stop the pipeline walk when reaching the
   * until entity. This is used to disable a partially started pipeline due to a
   * subdev start error.
   */
  static int iss_pipeline_disable(struct iss_pipeline *pipe,
  				struct media_entity *until)
  {
  	struct iss_device *iss = pipe->output->iss;
  	struct media_entity *entity;
  	struct media_pad *pad;
  	struct v4l2_subdev *subdev;
  	int failure = 0;
  	int ret;
  
  	entity = &pipe->output->video.entity;
  	while (1) {
  		pad = &entity->pads[0];
  		if (!(pad->flags & MEDIA_PAD_FL_SINK))
  			break;
  
  		pad = media_entity_remote_pad(pad);
  		if (pad == NULL ||
  		    media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
  			break;
  
  		entity = pad->entity;
  		if (entity == until)
  			break;
  
  		subdev = media_entity_to_v4l2_subdev(entity);
  		ret = v4l2_subdev_call(subdev, video, s_stream, 0);
  		if (ret < 0) {
  			dev_dbg(iss->dev, "%s: module stop timeout.\n",
  				subdev->name);
  			/* If the entity failed to stopped, assume it has
  			 * crashed. Mark it as such, the ISS will be reset when
  			 * applications will release it.
  			 */
  			iss->crashed |= 1U << subdev->entity.id;
  			failure = -ETIMEDOUT;
  		}
  	}
  
  	return failure;
  }
  
  /*
   * iss_pipeline_enable - Enable streaming on a pipeline
   * @pipe: ISS pipeline
   * @mode: Stream mode (single shot or continuous)
   *
   * Walk the entities chain starting at the pipeline output video node and start
   * all modules in the chain in the given mode.
   *
   * Return 0 if successful, or the return value of the failed video::s_stream
   * operation otherwise.
   */
  static int iss_pipeline_enable(struct iss_pipeline *pipe,
  			       enum iss_pipeline_stream_state mode)
  {
  	struct iss_device *iss = pipe->output->iss;
  	struct media_entity *entity;
  	struct media_pad *pad;
  	struct v4l2_subdev *subdev;
  	unsigned long flags;
  	int ret;
  
  	/* If one of the entities in the pipeline has crashed it will not work
  	 * properly. Refuse to start streaming in that case. This check must be
  	 * performed before the loop below to avoid starting entities if the
  	 * pipeline won't start anyway (those entities would then likely fail to
  	 * stop, making the problem worse).
  	 */
  	if (pipe->entities & iss->crashed)
  		return -EIO;
  
  	spin_lock_irqsave(&pipe->lock, flags);
  	pipe->state &= ~(ISS_PIPELINE_IDLE_INPUT | ISS_PIPELINE_IDLE_OUTPUT);
  	spin_unlock_irqrestore(&pipe->lock, flags);
  
  	pipe->do_propagation = false;
  
  	entity = &pipe->output->video.entity;
  	while (1) {
  		pad = &entity->pads[0];
  		if (!(pad->flags & MEDIA_PAD_FL_SINK))
  			break;
  
  		pad = media_entity_remote_pad(pad);
  		if (pad == NULL ||
  		    media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
  			break;
  
  		entity = pad->entity;
  		subdev = media_entity_to_v4l2_subdev(entity);
  
  		ret = v4l2_subdev_call(subdev, video, s_stream, mode);
  		if (ret < 0 && ret != -ENOIOCTLCMD) {
  			iss_pipeline_disable(pipe, entity);
  			return ret;
  		}
  
  		if (subdev == &iss->csi2a.subdev ||
  		    subdev == &iss->csi2b.subdev)
  			pipe->do_propagation = true;
  	}
  
  	iss_print_status(pipe->output->iss);
  	return 0;
  }
  
  /*
   * omap4iss_pipeline_set_stream - Enable/disable streaming on a pipeline
   * @pipe: ISS pipeline
   * @state: Stream state (stopped, single shot or continuous)
   *
   * Set the pipeline to the given stream state. Pipelines can be started in
   * single-shot or continuous mode.
   *
   * Return 0 if successful, or the return value of the failed video::s_stream
   * operation otherwise. The pipeline state is not updated when the operation
   * fails, except when stopping the pipeline.
   */
  int omap4iss_pipeline_set_stream(struct iss_pipeline *pipe,
  				 enum iss_pipeline_stream_state state)
  {
  	int ret;
  
  	if (state == ISS_PIPELINE_STREAM_STOPPED)
  		ret = iss_pipeline_disable(pipe, NULL);
  	else
  		ret = iss_pipeline_enable(pipe, state);
  
  	if (ret == 0 || state == ISS_PIPELINE_STREAM_STOPPED)
  		pipe->stream_state = state;
  
  	return ret;
  }
  
  /*
   * omap4iss_pipeline_cancel_stream - Cancel stream on a pipeline
   * @pipe: ISS pipeline
   *
   * Cancelling a stream mark all buffers on all video nodes in the pipeline as
   * erroneous and makes sure no new buffer can be queued. This function is called
   * when a fatal error that prevents any further operation on the pipeline
   * occurs.
   */
  void omap4iss_pipeline_cancel_stream(struct iss_pipeline *pipe)
  {
  	if (pipe->input)
  		omap4iss_video_cancel_stream(pipe->input);
  	if (pipe->output)
  		omap4iss_video_cancel_stream(pipe->output);
  }
  
  /*
   * iss_pipeline_is_last - Verify if entity has an enabled link to the output
   *			  video node
   * @me: ISS module's media entity
   *
   * Returns 1 if the entity has an enabled link to the output video node or 0
   * otherwise. It's true only while pipeline can have no more than one output
   * node.
   */
  static int iss_pipeline_is_last(struct media_entity *me)
  {
  	struct iss_pipeline *pipe;
  	struct media_pad *pad;
  
  	if (!me->pipe)
  		return 0;
  	pipe = to_iss_pipeline(me);
  	if (pipe->stream_state == ISS_PIPELINE_STREAM_STOPPED)
  		return 0;
  	pad = media_entity_remote_pad(&pipe->output->pad);
  	return pad->entity == me;
  }
  
  static int iss_reset(struct iss_device *iss)
  {
  	unsigned int timeout;
  
  	iss_reg_set(iss, OMAP4_ISS_MEM_TOP, ISS_HL_SYSCONFIG,
  		    ISS_HL_SYSCONFIG_SOFTRESET);
  
  	timeout = iss_poll_condition_timeout(
  		!(iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_HL_SYSCONFIG) &
  		ISS_HL_SYSCONFIG_SOFTRESET), 1000, 10, 100);
  	if (timeout) {
  		dev_err(iss->dev, "ISS reset timeout\n");
  		return -ETIMEDOUT;
  	}
  
  	iss->crashed = 0;
  	return 0;
  }
  
  static int iss_isp_reset(struct iss_device *iss)
  {
  	unsigned int timeout;
  
  	/* Fist, ensure that the ISP is IDLE (no transactions happening) */
  	iss_reg_update(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_SYSCONFIG,
  		       ISP5_SYSCONFIG_STANDBYMODE_MASK,
  		       ISP5_SYSCONFIG_STANDBYMODE_SMART);
  
  	iss_reg_set(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_CTRL, ISP5_CTRL_MSTANDBY);
  
  	timeout = iss_poll_condition_timeout(
  		iss_reg_read(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_CTRL) &
  		ISP5_CTRL_MSTANDBY_WAIT, 1000000, 1000, 1500);
  	if (timeout) {
  		dev_err(iss->dev, "ISP5 standby timeout\n");
  		return -ETIMEDOUT;
  	}
  
  	/* Now finally, do the reset */
  	iss_reg_set(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_SYSCONFIG,
  		    ISP5_SYSCONFIG_SOFTRESET);
  
  	timeout = iss_poll_condition_timeout(
  		!(iss_reg_read(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_SYSCONFIG) &
  		ISP5_SYSCONFIG_SOFTRESET), 1000000, 1000, 1500);
  	if (timeout) {
  		dev_err(iss->dev, "ISP5 reset timeout\n");
  		return -ETIMEDOUT;
  	}
  
  	return 0;
  }
  
  /*
   * iss_module_sync_idle - Helper to sync module with its idle state
   * @me: ISS submodule's media entity
   * @wait: ISS submodule's wait queue for streamoff/interrupt synchronization
   * @stopping: flag which tells module wants to stop
   *
   * This function checks if ISS submodule needs to wait for next interrupt. If
   * yes, makes the caller to sleep while waiting for such event.
   */
  int omap4iss_module_sync_idle(struct media_entity *me, wait_queue_head_t *wait,
  			      atomic_t *stopping)
  {
  	struct iss_pipeline *pipe = to_iss_pipeline(me);
  	struct iss_video *video = pipe->output;
  	unsigned long flags;
  
  	if (pipe->stream_state == ISS_PIPELINE_STREAM_STOPPED ||
  	    (pipe->stream_state == ISS_PIPELINE_STREAM_SINGLESHOT &&
  	     !iss_pipeline_ready(pipe)))
  		return 0;
  
  	/*
  	 * atomic_set() doesn't include memory barrier on ARM platform for SMP
  	 * scenario. We'll call it here to avoid race conditions.
  	 */
  	atomic_set(stopping, 1);
  	smp_wmb();
  
  	/*
  	 * If module is the last one, it's writing to memory. In this case,
  	 * it's necessary to check if the module is already paused due to
  	 * DMA queue underrun or if it has to wait for next interrupt to be
  	 * idle.
  	 * If it isn't the last one, the function won't sleep but *stopping
  	 * will still be set to warn next submodule caller's interrupt the
  	 * module wants to be idle.
  	 */
  	if (!iss_pipeline_is_last(me))
  		return 0;
  
  	spin_lock_irqsave(&video->qlock, flags);
  	if (video->dmaqueue_flags & ISS_VIDEO_DMAQUEUE_UNDERRUN) {
  		spin_unlock_irqrestore(&video->qlock, flags);
  		atomic_set(stopping, 0);
  		smp_wmb();
  		return 0;
  	}
  	spin_unlock_irqrestore(&video->qlock, flags);
  	if (!wait_event_timeout(*wait, !atomic_read(stopping),
  				msecs_to_jiffies(1000))) {
  		atomic_set(stopping, 0);
  		smp_wmb();
  		return -ETIMEDOUT;
  	}
  
  	return 0;
  }
  
  /*
   * omap4iss_module_sync_is_stopped - Helper to verify if module was stopping
   * @wait: ISS submodule's wait queue for streamoff/interrupt synchronization
   * @stopping: flag which tells module wants to stop
   *
   * This function checks if ISS submodule was stopping. In case of yes, it
   * notices the caller by setting stopping to 0 and waking up the wait queue.
   * Returns 1 if it was stopping or 0 otherwise.
   */
  int omap4iss_module_sync_is_stopping(wait_queue_head_t *wait,
  				     atomic_t *stopping)
  {
  	if (atomic_cmpxchg(stopping, 1, 0)) {
  		wake_up(wait);
  		return 1;
  	}
  
  	return 0;
  }
  
  /* --------------------------------------------------------------------------
   * Clock management
   */
  
  #define ISS_CLKCTRL_MASK	(ISS_CLKCTRL_CSI2_A |\
  				 ISS_CLKCTRL_CSI2_B |\
  				 ISS_CLKCTRL_ISP)
  
  static int __iss_subclk_update(struct iss_device *iss)
  {
  	u32 clk = 0;
  	int ret = 0, timeout = 1000;
  
  	if (iss->subclk_resources & OMAP4_ISS_SUBCLK_CSI2_A)
  		clk |= ISS_CLKCTRL_CSI2_A;
  
  	if (iss->subclk_resources & OMAP4_ISS_SUBCLK_CSI2_B)
  		clk |= ISS_CLKCTRL_CSI2_B;
  
  	if (iss->subclk_resources & OMAP4_ISS_SUBCLK_ISP)
  		clk |= ISS_CLKCTRL_ISP;
  
  	iss_reg_update(iss, OMAP4_ISS_MEM_TOP, ISS_CLKCTRL,
  		       ISS_CLKCTRL_MASK, clk);
  
  	/* Wait for HW assertion */
  	while (--timeout > 0) {
  		udelay(1);
  		if ((iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_CLKSTAT) &
  		    ISS_CLKCTRL_MASK) == clk)
  			break;
  	}
  
  	if (!timeout)
  		ret = -EBUSY;
  
  	return ret;
  }
  
  int omap4iss_subclk_enable(struct iss_device *iss,
  			    enum iss_subclk_resource res)
  {
  	iss->subclk_resources |= res;
  
  	return __iss_subclk_update(iss);
  }
  
  int omap4iss_subclk_disable(struct iss_device *iss,
  			     enum iss_subclk_resource res)
  {
  	iss->subclk_resources &= ~res;
  
  	return __iss_subclk_update(iss);
  }
  
  #define ISS_ISP5_CLKCTRL_MASK	(ISP5_CTRL_BL_CLK_ENABLE |\
  				 ISP5_CTRL_ISIF_CLK_ENABLE |\
  				 ISP5_CTRL_H3A_CLK_ENABLE |\
  				 ISP5_CTRL_RSZ_CLK_ENABLE |\
  				 ISP5_CTRL_IPIPE_CLK_ENABLE |\
  				 ISP5_CTRL_IPIPEIF_CLK_ENABLE)
  
  static void __iss_isp_subclk_update(struct iss_device *iss)
  {
  	u32 clk = 0;
  
  	if (iss->isp_subclk_resources & OMAP4_ISS_ISP_SUBCLK_ISIF)
  		clk |= ISP5_CTRL_ISIF_CLK_ENABLE;
  
  	if (iss->isp_subclk_resources & OMAP4_ISS_ISP_SUBCLK_H3A)
  		clk |= ISP5_CTRL_H3A_CLK_ENABLE;
  
  	if (iss->isp_subclk_resources & OMAP4_ISS_ISP_SUBCLK_RSZ)
  		clk |= ISP5_CTRL_RSZ_CLK_ENABLE;
  
  	if (iss->isp_subclk_resources & OMAP4_ISS_ISP_SUBCLK_IPIPE)
  		clk |= ISP5_CTRL_IPIPE_CLK_ENABLE;
  
  	if (iss->isp_subclk_resources & OMAP4_ISS_ISP_SUBCLK_IPIPEIF)
  		clk |= ISP5_CTRL_IPIPEIF_CLK_ENABLE;
  
  	if (clk)
  		clk |= ISP5_CTRL_BL_CLK_ENABLE;
  
  	iss_reg_update(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_CTRL,
  		       ISS_ISP5_CLKCTRL_MASK, clk);
  }
  
  void omap4iss_isp_subclk_enable(struct iss_device *iss,
  				enum iss_isp_subclk_resource res)
  {
  	iss->isp_subclk_resources |= res;
  
  	__iss_isp_subclk_update(iss);
  }
  
  void omap4iss_isp_subclk_disable(struct iss_device *iss,
  				 enum iss_isp_subclk_resource res)
  {
  	iss->isp_subclk_resources &= ~res;
  
  	__iss_isp_subclk_update(iss);
  }
  
  /*
   * iss_enable_clocks - Enable ISS clocks
   * @iss: OMAP4 ISS device
   *
   * Return 0 if successful, or clk_enable return value if any of tthem fails.
   */
  static int iss_enable_clocks(struct iss_device *iss)
  {
  	int ret;
  
  	ret = clk_enable(iss->iss_fck);
  	if (ret) {
  		dev_err(iss->dev, "clk_enable iss_fck failed\n");
  		return ret;
  	}
  
  	ret = clk_enable(iss->iss_ctrlclk);
  	if (ret) {
  		dev_err(iss->dev, "clk_enable iss_ctrlclk failed\n");
  		clk_disable(iss->iss_fck);
  		return ret;
  	}
  
  	return 0;
  }
  
  /*
   * iss_disable_clocks - Disable ISS clocks
   * @iss: OMAP4 ISS device
   */
  static void iss_disable_clocks(struct iss_device *iss)
  {
  	clk_disable(iss->iss_ctrlclk);
  	clk_disable(iss->iss_fck);
  }
  
  static int iss_get_clocks(struct iss_device *iss)
  {
  	iss->iss_fck = devm_clk_get(iss->dev, "iss_fck");
  	if (IS_ERR(iss->iss_fck)) {
  		dev_err(iss->dev, "Unable to get iss_fck clock info\n");
  		return PTR_ERR(iss->iss_fck);
  	}
  
  	iss->iss_ctrlclk = devm_clk_get(iss->dev, "iss_ctrlclk");
  	if (IS_ERR(iss->iss_ctrlclk)) {
  		dev_err(iss->dev, "Unable to get iss_ctrlclk clock info\n");
  		return PTR_ERR(iss->iss_ctrlclk);
  	}
  
  	return 0;
  }
  
  /*
   * omap4iss_get - Acquire the ISS resource.
   *
   * Initializes the clocks for the first acquire.
   *
   * Increment the reference count on the ISS. If the first reference is taken,
   * enable clocks and power-up all submodules.
   *
   * Return a pointer to the ISS device structure, or NULL if an error occurred.
   */
  struct iss_device *omap4iss_get(struct iss_device *iss)
  {
  	struct iss_device *__iss = iss;
  
  	if (iss == NULL)
  		return NULL;
  
  	mutex_lock(&iss->iss_mutex);
  	if (iss->ref_count > 0)
  		goto out;
  
  	if (iss_enable_clocks(iss) < 0) {
  		__iss = NULL;
  		goto out;
  	}
  
  	iss_enable_interrupts(iss);
  
  out:
  	if (__iss != NULL)
  		iss->ref_count++;
  	mutex_unlock(&iss->iss_mutex);
  
  	return __iss;
  }
  
  /*
   * omap4iss_put - Release the ISS
   *
   * Decrement the reference count on the ISS. If the last reference is released,
   * power-down all submodules, disable clocks and free temporary buffers.
   */
  void omap4iss_put(struct iss_device *iss)
  {
  	if (iss == NULL)
  		return;
  
  	mutex_lock(&iss->iss_mutex);
  	BUG_ON(iss->ref_count == 0);
  	if (--iss->ref_count == 0) {
  		iss_disable_interrupts(iss);
  		/* Reset the ISS if an entity has failed to stop. This is the
  		 * only way to recover from such conditions, although it would
  		 * be worth investigating whether resetting the ISP only can't
  		 * fix the problem in some cases.
  		 */
  		if (iss->crashed)
  			iss_reset(iss);
  		iss_disable_clocks(iss);
  	}
  	mutex_unlock(&iss->iss_mutex);
  }
  
  static int iss_map_mem_resource(struct platform_device *pdev,
  				struct iss_device *iss,
  				enum iss_mem_resources res)
  {
  	struct resource *mem;
  
  	mem = platform_get_resource(pdev, IORESOURCE_MEM, res);
  
  	iss->regs[res] = devm_ioremap_resource(iss->dev, mem);
  
  	return PTR_ERR_OR_ZERO(iss->regs[res]);
  }
  
  static void iss_unregister_entities(struct iss_device *iss)
  {
  	omap4iss_resizer_unregister_entities(&iss->resizer);
  	omap4iss_ipipe_unregister_entities(&iss->ipipe);
  	omap4iss_ipipeif_unregister_entities(&iss->ipipeif);
  	omap4iss_csi2_unregister_entities(&iss->csi2a);
  	omap4iss_csi2_unregister_entities(&iss->csi2b);
  
  	v4l2_device_unregister(&iss->v4l2_dev);
  	media_device_unregister(&iss->media_dev);
  }
  
  /*
   * iss_register_subdev_group - Register a group of subdevices
   * @iss: OMAP4 ISS device
   * @board_info: I2C subdevs board information array
   *
   * Register all I2C subdevices in the board_info array. The array must be
   * terminated by a NULL entry, and the first entry must be the sensor.
   *
   * Return a pointer to the sensor media entity if it has been successfully
   * registered, or NULL otherwise.
   */
  static struct v4l2_subdev *
  iss_register_subdev_group(struct iss_device *iss,
  		     struct iss_subdev_i2c_board_info *board_info)
  {
  	struct v4l2_subdev *sensor = NULL;
  	unsigned int first;
  
  	if (board_info->board_info == NULL)
  		return NULL;
  
  	for (first = 1; board_info->board_info; ++board_info, first = 0) {
  		struct v4l2_subdev *subdev;
  		struct i2c_adapter *adapter;
  
  		adapter = i2c_get_adapter(board_info->i2c_adapter_id);
  		if (adapter == NULL) {
  			dev_err(iss->dev,
  				"%s: Unable to get I2C adapter %d for device %s\n",
  				__func__, board_info->i2c_adapter_id,
  				board_info->board_info->type);
  			continue;
  		}
  
  		subdev = v4l2_i2c_new_subdev_board(&iss->v4l2_dev, adapter,
  				board_info->board_info, NULL);
  		if (subdev == NULL) {
  			dev_err(iss->dev, "%s: Unable to register subdev %s\n",
  				__func__, board_info->board_info->type);
  			continue;
  		}
  
  		if (first)
  			sensor = subdev;
  	}
  
  	return sensor;
  }
  
  static int iss_register_entities(struct iss_device *iss)
  {
  	struct iss_platform_data *pdata = iss->pdata;
  	struct iss_v4l2_subdevs_group *subdevs;
  	int ret;
  
  	iss->media_dev.dev = iss->dev;
  	strlcpy(iss->media_dev.model, "TI OMAP4 ISS",
  		sizeof(iss->media_dev.model));
  	iss->media_dev.hw_revision = iss->revision;
  	iss->media_dev.link_notify = iss_pipeline_link_notify;
  	ret = media_device_register(&iss->media_dev);
  	if (ret < 0) {
  		dev_err(iss->dev, "%s: Media device registration failed (%d)\n",
  			__func__, ret);
  		return ret;
  	}
  
  	iss->v4l2_dev.mdev = &iss->media_dev;
  	ret = v4l2_device_register(iss->dev, &iss->v4l2_dev);
  	if (ret < 0) {
  		dev_err(iss->dev, "%s: V4L2 device registration failed (%d)\n",
  			__func__, ret);
  		goto done;
  	}
  
  	/* Register internal entities */
  	ret = omap4iss_csi2_register_entities(&iss->csi2a, &iss->v4l2_dev);
  	if (ret < 0)
  		goto done;
  
  	ret = omap4iss_csi2_register_entities(&iss->csi2b, &iss->v4l2_dev);
  	if (ret < 0)
  		goto done;
  
  	ret = omap4iss_ipipeif_register_entities(&iss->ipipeif, &iss->v4l2_dev);
  	if (ret < 0)
  		goto done;
  
  	ret = omap4iss_ipipe_register_entities(&iss->ipipe, &iss->v4l2_dev);
  	if (ret < 0)
  		goto done;
  
  	ret = omap4iss_resizer_register_entities(&iss->resizer, &iss->v4l2_dev);
  	if (ret < 0)
  		goto done;
  
  	/* Register external entities */
  	for (subdevs = pdata->subdevs; subdevs && subdevs->subdevs; ++subdevs) {
  		struct v4l2_subdev *sensor;
  		struct media_entity *input;
  		unsigned int flags;
  		unsigned int pad;
  
  		sensor = iss_register_subdev_group(iss, subdevs->subdevs);
  		if (sensor == NULL)
  			continue;
  
  		sensor->host_priv = subdevs;
  
  		/* Connect the sensor to the correct interface module.
  		 * CSI2a receiver through CSIPHY1, or
  		 * CSI2b receiver through CSIPHY2
  		 */
  		switch (subdevs->interface) {
  		case ISS_INTERFACE_CSI2A_PHY1:
  			input = &iss->csi2a.subdev.entity;
  			pad = CSI2_PAD_SINK;
  			flags = MEDIA_LNK_FL_IMMUTABLE
  			      | MEDIA_LNK_FL_ENABLED;
  			break;
  
  		case ISS_INTERFACE_CSI2B_PHY2:
  			input = &iss->csi2b.subdev.entity;
  			pad = CSI2_PAD_SINK;
  			flags = MEDIA_LNK_FL_IMMUTABLE
  			      | MEDIA_LNK_FL_ENABLED;
  			break;
  
  		default:
  			dev_err(iss->dev, "%s: invalid interface type %u\n",
  				__func__, subdevs->interface);
  			ret = -EINVAL;
  			goto done;
  		}
  
  		ret = media_entity_create_link(&sensor->entity, 0, input, pad,
  					       flags);
  		if (ret < 0)
  			goto done;
  	}
  
  	ret = v4l2_device_register_subdev_nodes(&iss->v4l2_dev);
  
  done:
  	if (ret < 0)
  		iss_unregister_entities(iss);
  
  	return ret;
  }
  
  static void iss_cleanup_modules(struct iss_device *iss)
  {
  	omap4iss_csi2_cleanup(iss);
  	omap4iss_ipipeif_cleanup(iss);
  	omap4iss_ipipe_cleanup(iss);
  	omap4iss_resizer_cleanup(iss);
  }
  
  static int iss_initialize_modules(struct iss_device *iss)
  {
  	int ret;
  
  	ret = omap4iss_csiphy_init(iss);
  	if (ret < 0) {
  		dev_err(iss->dev, "CSI PHY initialization failed\n");
  		goto error_csiphy;
  	}
  
  	ret = omap4iss_csi2_init(iss);
  	if (ret < 0) {
  		dev_err(iss->dev, "CSI2 initialization failed\n");
  		goto error_csi2;
  	}
  
  	ret = omap4iss_ipipeif_init(iss);
  	if (ret < 0) {
  		dev_err(iss->dev, "ISP IPIPEIF initialization failed\n");
  		goto error_ipipeif;
  	}
  
  	ret = omap4iss_ipipe_init(iss);
  	if (ret < 0) {
  		dev_err(iss->dev, "ISP IPIPE initialization failed\n");
  		goto error_ipipe;
  	}
  
  	ret = omap4iss_resizer_init(iss);
  	if (ret < 0) {
  		dev_err(iss->dev, "ISP RESIZER initialization failed\n");
  		goto error_resizer;
  	}
  
  	/* Connect the submodules. */
  	ret = media_entity_create_link(
  			&iss->csi2a.subdev.entity, CSI2_PAD_SOURCE,
  			&iss->ipipeif.subdev.entity, IPIPEIF_PAD_SINK, 0);
  	if (ret < 0)
  		goto error_link;
  
  	ret = media_entity_create_link(
  			&iss->csi2b.subdev.entity, CSI2_PAD_SOURCE,
  			&iss->ipipeif.subdev.entity, IPIPEIF_PAD_SINK, 0);
  	if (ret < 0)
  		goto error_link;
  
  	ret = media_entity_create_link(
  			&iss->ipipeif.subdev.entity, IPIPEIF_PAD_SOURCE_VP,
  			&iss->resizer.subdev.entity, RESIZER_PAD_SINK, 0);
  	if (ret < 0)
  		goto error_link;
  
  	ret = media_entity_create_link(
  			&iss->ipipeif.subdev.entity, IPIPEIF_PAD_SOURCE_VP,
  			&iss->ipipe.subdev.entity, IPIPE_PAD_SINK, 0);
  	if (ret < 0)
  		goto error_link;
  
  	ret = media_entity_create_link(
  			&iss->ipipe.subdev.entity, IPIPE_PAD_SOURCE_VP,
  			&iss->resizer.subdev.entity, RESIZER_PAD_SINK, 0);
  	if (ret < 0)
  		goto error_link;
  
  	return 0;
  
  error_link:
  	omap4iss_resizer_cleanup(iss);
  error_resizer:
  	omap4iss_ipipe_cleanup(iss);
  error_ipipe:
  	omap4iss_ipipeif_cleanup(iss);
  error_ipipeif:
  	omap4iss_csi2_cleanup(iss);
  error_csi2:
  error_csiphy:
  	return ret;
  }
  
  static int iss_probe(struct platform_device *pdev)
  {
  	struct iss_platform_data *pdata = pdev->dev.platform_data;
  	struct iss_device *iss;
  	unsigned int i;
  	int ret;
  
  	if (pdata == NULL)
  		return -EINVAL;
  
  	iss = devm_kzalloc(&pdev->dev, sizeof(*iss), GFP_KERNEL);
  	if (!iss)
  		return -ENOMEM;
  
  	mutex_init(&iss->iss_mutex);
  
  	iss->dev = &pdev->dev;
  	iss->pdata = pdata;
  
  	iss->raw_dmamask = DMA_BIT_MASK(32);
  	iss->dev->dma_mask = &iss->raw_dmamask;
  	iss->dev->coherent_dma_mask = DMA_BIT_MASK(32);
  
  	platform_set_drvdata(pdev, iss);
  
  	/* Clocks */
  	ret = iss_map_mem_resource(pdev, iss, OMAP4_ISS_MEM_TOP);
  	if (ret < 0)
  		goto error;
  
  	ret = iss_get_clocks(iss);
  	if (ret < 0)
  		goto error;
  
  	if (omap4iss_get(iss) == NULL)
  		goto error;
  
  	ret = iss_reset(iss);
  	if (ret < 0)
  		goto error_iss;
  
  	iss->revision = iss_reg_read(iss, OMAP4_ISS_MEM_TOP, ISS_HL_REVISION);
  	dev_info(iss->dev, "Revision %08x found\n", iss->revision);
  
  	for (i = 1; i < OMAP4_ISS_MEM_LAST; i++) {
  		ret = iss_map_mem_resource(pdev, iss, i);
  		if (ret)
  			goto error_iss;
  	}
  
  	/* Configure BTE BW_LIMITER field to max recommended value (1 GB) */
  	iss_reg_update(iss, OMAP4_ISS_MEM_BTE, BTE_CTRL,
  		       BTE_CTRL_BW_LIMITER_MASK,
  		       18 << BTE_CTRL_BW_LIMITER_SHIFT);
  
  	/* Perform ISP reset */
  	ret = omap4iss_subclk_enable(iss, OMAP4_ISS_SUBCLK_ISP);
  	if (ret < 0)
  		goto error_iss;
  
  	ret = iss_isp_reset(iss);
  	if (ret < 0)
  		goto error_iss;
  
  	dev_info(iss->dev, "ISP Revision %08x found\n",
  		 iss_reg_read(iss, OMAP4_ISS_MEM_ISP_SYS1, ISP5_REVISION));
  
  	/* Interrupt */
  	iss->irq_num = platform_get_irq(pdev, 0);
  	if (iss->irq_num <= 0) {
  		dev_err(iss->dev, "No IRQ resource\n");
  		ret = -ENODEV;
  		goto error_iss;
  	}
  
  	if (devm_request_irq(iss->dev, iss->irq_num, iss_isr, IRQF_SHARED,
  			     "OMAP4 ISS", iss)) {
  		dev_err(iss->dev, "Unable to request IRQ\n");
  		ret = -EINVAL;
  		goto error_iss;
  	}
  
  	/* Entities */
  	ret = iss_initialize_modules(iss);
  	if (ret < 0)
  		goto error_iss;
  
  	ret = iss_register_entities(iss);
  	if (ret < 0)
  		goto error_modules;
  
  	omap4iss_put(iss);
  
  	return 0;
  
  error_modules:
  	iss_cleanup_modules(iss);
  error_iss:
  	omap4iss_put(iss);
  error:
  	platform_set_drvdata(pdev, NULL);
  
  	mutex_destroy(&iss->iss_mutex);
  
  	return ret;
  }
  
  static int iss_remove(struct platform_device *pdev)
  {
  	struct iss_device *iss = platform_get_drvdata(pdev);
  
  	iss_unregister_entities(iss);
  	iss_cleanup_modules(iss);
  
  	return 0;
  }
  
  static struct platform_device_id omap4iss_id_table[] = {
  	{ "omap4iss", 0 },
  	{ },
  };
  MODULE_DEVICE_TABLE(platform, omap4iss_id_table);
  
  static struct platform_driver iss_driver = {
  	.probe		= iss_probe,
  	.remove		= iss_remove,
  	.id_table	= omap4iss_id_table,
  	.driver = {
  		.name	= "omap4iss",
  	},
  };
  
  module_platform_driver(iss_driver);
  
  MODULE_DESCRIPTION("TI OMAP4 ISS driver");
  MODULE_AUTHOR("Sergio Aguirre <sergio.a.aguirre@gmail.com>");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(ISS_VIDEO_DRIVER_VERSION);
  