text: /*
   * MSM MDDI Transport
   *
   * Copyright (C) 2007 Google Incorporated
   * Copyright (C) 2007 QUALCOMM Incorporated
   *
   * This software is licensed under the terms of the GNU General Public
   * License version 2, as published by the Free Software Foundation, and
   * may be copied, distributed, and modified under those terms.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
   * GNU General Public License for more details.
   *
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/dma-mapping.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  #include <linux/delay.h>
  #include <linux/gfp.h>
  #include <linux/spinlock.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  #include <linux/sched.h>
  #include <linux/platform_data/video-msm_fb.h>
  #include "mddi_hw.h"
  
  #define FLAG_DISABLE_HIBERNATION 0x0001
  #define FLAG_HAVE_CAPS		 0x0002
  #define FLAG_HAS_VSYNC_IRQ	 0x0004
  #define FLAG_HAVE_STATUS	 0x0008
  
  #define CMD_GET_CLIENT_CAP     0x0601
  #define CMD_GET_CLIENT_STATUS  0x0602
  
  union mddi_rev {
  	unsigned char raw[MDDI_REV_BUFFER_SIZE];
  	struct mddi_rev_packet hdr;
  	struct mddi_client_status status;
  	struct mddi_client_caps caps;
  	struct mddi_register_access reg;
  };
  
  struct reg_read_info {
  	struct completion done;
  	uint32_t reg;
  	uint32_t status;
  	uint32_t result;
  };
  
  struct mddi_info {
  	uint16_t flags;
  	uint16_t version;
  	char __iomem *base;
  	int irq;
  	struct clk *clk;
  	struct msm_mddi_client_data client_data;
  
  	/* buffer for rev encap packets */
  	void *rev_data;
  	dma_addr_t rev_addr;
  	struct mddi_llentry *reg_write_data;
  	dma_addr_t reg_write_addr;
  	struct mddi_llentry *reg_read_data;
  	dma_addr_t reg_read_addr;
  	size_t rev_data_curr;
  
  	spinlock_t int_lock;
  	uint32_t int_enable;
  	uint32_t got_int;
  	wait_queue_head_t int_wait;
  
  	struct mutex reg_write_lock;
  	struct mutex reg_read_lock;
  	struct reg_read_info *reg_read;
  
  	struct mddi_client_caps caps;
  	struct mddi_client_status status;
  
  	void (*power_client)(struct msm_mddi_client_data *, int);
  
  	/* client device published to bind us to the
  	 * appropriate mddi_client driver
  	 */
  	char client_name[20];
  
  	struct platform_device client_pdev;
  };
  
  static void mddi_init_rev_encap(struct mddi_info *mddi);
  
  #define mddi_readl(r) readl(mddi->base + (MDDI_##r))
  #define mddi_writel(v, r) writel((v), mddi->base + (MDDI_##r))
  
  void mddi_activate_link(struct msm_mddi_client_data *cdata)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  
  	mddi_writel(MDDI_CMD_LINK_ACTIVE, CMD);
  }
  
  static void mddi_handle_link_list_done(struct mddi_info *mddi)
  {
  }
  
  static void mddi_reset_rev_encap_ptr(struct mddi_info *mddi)
  {
  	printk(KERN_INFO "mddi: resetting rev ptr\n");
  	mddi->rev_data_curr = 0;
  	mddi_writel(mddi->rev_addr, REV_PTR);
  	mddi_writel(mddi->rev_addr, REV_PTR);
  	mddi_writel(MDDI_CMD_FORCE_NEW_REV_PTR, CMD);
  }
  
  static void mddi_handle_rev_data(struct mddi_info *mddi, union mddi_rev *rev)
  {
  	int i;
  	struct reg_read_info *ri;
  
  	if ((rev->hdr.length <= MDDI_REV_BUFFER_SIZE - 2) &&
  	   (rev->hdr.length >= sizeof(struct mddi_rev_packet) - 2)) {
  
  		switch (rev->hdr.type) {
  		case TYPE_CLIENT_CAPS:
  			memcpy(&mddi->caps, &rev->caps,
  			       sizeof(struct mddi_client_caps));
  			mddi->flags |= FLAG_HAVE_CAPS;
  			wake_up(&mddi->int_wait);
  			break;
  		case TYPE_CLIENT_STATUS:
  			memcpy(&mddi->status, &rev->status,
  			       sizeof(struct mddi_client_status));
  			mddi->flags |= FLAG_HAVE_STATUS;
  			wake_up(&mddi->int_wait);
  			break;
  		case TYPE_REGISTER_ACCESS:
  			ri = mddi->reg_read;
  			if (ri == 0) {
  				printk(KERN_INFO "rev: got reg %x = %x without "
  						 " pending read\n",
  				       rev->reg.register_address,
  				       rev->reg.register_data_list);
  				break;
  			}
  			if (ri->reg != rev->reg.register_address) {
  				printk(KERN_INFO "rev: got reg %x = %x for "
  						 "wrong register, expected "
  						 "%x\n",
  				       rev->reg.register_address,
  				       rev->reg.register_data_list, ri->reg);
  				break;
  			}
  			mddi->reg_read = NULL;
  			ri->status = 0;
  			ri->result = rev->reg.register_data_list;
  			complete(&ri->done);
  			break;
  		default:
  			printk(KERN_INFO "rev: unknown reverse packet: "
  					 "len=%04x type=%04x CURR_REV_PTR=%x\n",
  			       rev->hdr.length, rev->hdr.type,
  			       mddi_readl(CURR_REV_PTR));
  			for (i = 0; i < rev->hdr.length + 2; i++) {
  				if ((i % 16) == 0)
  					printk(KERN_INFO "\n");
  				printk(KERN_INFO " %02x", rev->raw[i]);
  			}
  			printk(KERN_INFO "\n");
  			mddi_reset_rev_encap_ptr(mddi);
  		}
  	} else {
  		printk(KERN_INFO "bad rev length, %d, CURR_REV_PTR %x\n",
  		       rev->hdr.length, mddi_readl(CURR_REV_PTR));
  		mddi_reset_rev_encap_ptr(mddi);
  	}
  }
  
  static void mddi_wait_interrupt(struct mddi_info *mddi, uint32_t intmask);
  
  static void mddi_handle_rev_data_avail(struct mddi_info *mddi)
  {
  	uint32_t rev_data_count;
  	uint32_t rev_crc_err_count;
  	struct reg_read_info *ri;
  	size_t prev_offset;
  	uint16_t length;
  
  	union mddi_rev *crev = mddi->rev_data + mddi->rev_data_curr;
  
  	/* clear the interrupt */
  	mddi_writel(MDDI_INT_REV_DATA_AVAIL, INT);
  	rev_data_count = mddi_readl(REV_PKT_CNT);
  	rev_crc_err_count = mddi_readl(REV_CRC_ERR);
  	if (rev_data_count > 1)
  		printk(KERN_INFO "rev_data_count %d\n", rev_data_count);
  
  	if (rev_crc_err_count) {
  		printk(KERN_INFO "rev_crc_err_count %d, INT %x\n",
  		       rev_crc_err_count,  mddi_readl(INT));
  		ri = mddi->reg_read;
  		if (ri == 0) {
  			printk(KERN_INFO "rev: got crc error without pending "
  			       "read\n");
  		} else {
  			mddi->reg_read = NULL;
  			ri->status = -EIO;
  			ri->result = -1;
  			complete(&ri->done);
  		}
  	}
  
  	if (rev_data_count == 0)
  		return;
  
  	prev_offset = mddi->rev_data_curr;
  
  	length = *((uint8_t *)mddi->rev_data + mddi->rev_data_curr);
  	mddi->rev_data_curr++;
  	if (mddi->rev_data_curr == MDDI_REV_BUFFER_SIZE)
  		mddi->rev_data_curr = 0;
  	length += *((uint8_t *)mddi->rev_data + mddi->rev_data_curr) << 8;
  	mddi->rev_data_curr += 1 + length;
  	if (mddi->rev_data_curr >= MDDI_REV_BUFFER_SIZE)
  		mddi->rev_data_curr =
  			mddi->rev_data_curr % MDDI_REV_BUFFER_SIZE;
  
  	if (length > MDDI_REV_BUFFER_SIZE - 2) {
  		printk(KERN_INFO "mddi: rev data length greater than buffer"
  			"size\n");
  		mddi_reset_rev_encap_ptr(mddi);
  		return;
  	}
  
  	if (prev_offset + 2 + length >= MDDI_REV_BUFFER_SIZE) {
  		union mddi_rev tmprev;
  		size_t rem = MDDI_REV_BUFFER_SIZE - prev_offset;
  		memcpy(&tmprev.raw[0], mddi->rev_data + prev_offset, rem);
  		memcpy(&tmprev.raw[rem], mddi->rev_data, 2 + length - rem);
  		mddi_handle_rev_data(mddi, &tmprev);
  	} else {
  		mddi_handle_rev_data(mddi, crev);
  	}
  
  	if (prev_offset < MDDI_REV_BUFFER_SIZE / 2 &&
  	    mddi->rev_data_curr >= MDDI_REV_BUFFER_SIZE / 2) {
  		mddi_writel(mddi->rev_addr, REV_PTR);
  	}
  }
  
  static irqreturn_t mddi_isr(int irq, void *data)
  {
  	struct msm_mddi_client_data *cdata = data;
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	uint32_t active, status;
  
  	spin_lock(&mddi->int_lock);
  
  	active = mddi_readl(INT);
  	status = mddi_readl(STAT);
  
  	mddi_writel(active, INT);
  
  	/* ignore any interrupts we have disabled */
  	active &= mddi->int_enable;
  
  	mddi->got_int |= active;
  	wake_up(&mddi->int_wait);
  
  	if (active & MDDI_INT_PRI_LINK_LIST_DONE) {
  		mddi->int_enable &= (~MDDI_INT_PRI_LINK_LIST_DONE);
  		mddi_handle_link_list_done(mddi);
  	}
  	if (active & MDDI_INT_REV_DATA_AVAIL)
  		mddi_handle_rev_data_avail(mddi);
  
  	if (active & ~MDDI_INT_NEED_CLEAR)
  		mddi->int_enable &= ~(active & ~MDDI_INT_NEED_CLEAR);
  
  	if (active & MDDI_INT_LINK_ACTIVE) {
  		mddi->int_enable &= (~MDDI_INT_LINK_ACTIVE);
  		mddi->int_enable |= MDDI_INT_IN_HIBERNATION;
  	}
  
  	if (active & MDDI_INT_IN_HIBERNATION) {
  		mddi->int_enable &= (~MDDI_INT_IN_HIBERNATION);
  		mddi->int_enable |= MDDI_INT_LINK_ACTIVE;
  	}
  
  	mddi_writel(mddi->int_enable, INTEN);
  	spin_unlock(&mddi->int_lock);
  
  	return IRQ_HANDLED;
  }
  
  static long mddi_wait_interrupt_timeout(struct mddi_info *mddi,
  					uint32_t intmask, int timeout)
  {
  	unsigned long irq_flags;
  
  	spin_lock_irqsave(&mddi->int_lock, irq_flags);
  	mddi->got_int &= ~intmask;
  	mddi->int_enable |= intmask;
  	mddi_writel(mddi->int_enable, INTEN);
  	spin_unlock_irqrestore(&mddi->int_lock, irq_flags);
  	return wait_event_timeout(mddi->int_wait, mddi->got_int & intmask,
  				  timeout);
  }
  
  static void mddi_wait_interrupt(struct mddi_info *mddi, uint32_t intmask)
  {
  	if (mddi_wait_interrupt_timeout(mddi, intmask, HZ/10) == 0)
  		printk(KERN_INFO "mddi_wait_interrupt %d, timeout "
  		       "waiting for %x, INT = %x, STAT = %x gotint = %x\n",
  		       current->pid, intmask, mddi_readl(INT), mddi_readl(STAT),
  		       mddi->got_int);
  }
  
  static void mddi_init_rev_encap(struct mddi_info *mddi)
  {
  	memset(mddi->rev_data, 0xee, MDDI_REV_BUFFER_SIZE);
  	mddi_writel(mddi->rev_addr, REV_PTR);
  	mddi_writel(MDDI_CMD_FORCE_NEW_REV_PTR, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  }
  
  void mddi_set_auto_hibernate(struct msm_mddi_client_data *cdata, int on)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	mddi_writel(MDDI_CMD_POWERDOWN, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_IN_HIBERNATION);
  	mddi_writel(MDDI_CMD_HIBERNATE | !!on, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  }
  
  
  static uint16_t mddi_init_registers(struct mddi_info *mddi)
  {
  	mddi_writel(0x0001, VERSION);
  	mddi_writel(MDDI_HOST_BYTES_PER_SUBFRAME, BPS);
  	mddi_writel(0x0003, SPM); /* subframes per media */
  	mddi_writel(0x0005, TA1_LEN);
  	mddi_writel(MDDI_HOST_TA2_LEN, TA2_LEN);
  	mddi_writel(0x0096, DRIVE_HI);
  	/* 0x32 normal, 0x50 for Toshiba display */
  	mddi_writel(0x0050, DRIVE_LO);
  	mddi_writel(0x003C, DISP_WAKE); /* wakeup counter */
  	mddi_writel(MDDI_HOST_REV_RATE_DIV, REV_RATE_DIV);
  
  	mddi_writel(MDDI_REV_BUFFER_SIZE, REV_SIZE);
  	mddi_writel(MDDI_MAX_REV_PKT_SIZE, REV_ENCAP_SZ);
  
  	/* disable periodic rev encap */
  	mddi_writel(MDDI_CMD_PERIODIC_REV_ENCAP, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  
  	if (mddi_readl(PAD_CTL) == 0) {
  		/* If we are turning on band gap, need to wait 5us before
  		 * turning on the rest of the PAD */
  		mddi_writel(0x08000, PAD_CTL);
  		udelay(5);
  	}
  
  	/* Recommendation from PAD hw team */
  	mddi_writel(0xa850f, PAD_CTL);
  
  
  	/* Need an even number for counts */
  	mddi_writel(0x60006, DRIVER_START_CNT);
  
  	mddi_set_auto_hibernate(&mddi->client_data, 0);
  
  	mddi_writel(MDDI_CMD_DISP_IGNORE, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  
  	mddi_init_rev_encap(mddi);
  	return mddi_readl(CORE_VER) & 0xffff;
  }
  
  static void mddi_suspend(struct msm_mddi_client_data *cdata)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	/* turn off the client */
  	if (mddi->power_client)
  		mddi->power_client(&mddi->client_data, 0);
  	/* turn off the link */
  	mddi_writel(MDDI_CMD_RESET, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	/* turn off the clock */
  	clk_disable(mddi->clk);
  }
  
  static void mddi_resume(struct msm_mddi_client_data *cdata)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	mddi_set_auto_hibernate(&mddi->client_data, 0);
  	/* turn on the client */
  	if (mddi->power_client)
  		mddi->power_client(&mddi->client_data, 1);
  	/* turn on the clock */
  	clk_enable(mddi->clk);
  	/* set up the local registers */
  	mddi->rev_data_curr = 0;
  	mddi_init_registers(mddi);
  	mddi_writel(mddi->int_enable, INTEN);
  	mddi_writel(MDDI_CMD_LINK_ACTIVE, CMD);
  	mddi_writel(MDDI_CMD_SEND_RTD, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	mddi_set_auto_hibernate(&mddi->client_data, 1);
  }
  
  static int __devinit mddi_get_client_caps(struct mddi_info *mddi)
  {
  	int i, j;
  
  	/* clear any stale interrupts */
  	mddi_writel(0xffffffff, INT);
  
  	mddi->int_enable = MDDI_INT_LINK_ACTIVE |
  			   MDDI_INT_IN_HIBERNATION |
  			   MDDI_INT_PRI_LINK_LIST_DONE |
  			   MDDI_INT_REV_DATA_AVAIL |
  			   MDDI_INT_REV_OVERFLOW |
  			   MDDI_INT_REV_OVERWRITE |
  			   MDDI_INT_RTD_FAILURE;
  	mddi_writel(mddi->int_enable, INTEN);
  
  	mddi_writel(MDDI_CMD_LINK_ACTIVE, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  
  	for (j = 0; j < 3; j++) {
  		/* the toshiba vga panel does not respond to get
  		 * caps unless you SEND_RTD, but the first SEND_RTD
  		 * will fail...
  		 */
  		for (i = 0; i < 4; i++) {
  			uint32_t stat;
  
  			mddi_writel(MDDI_CMD_SEND_RTD, CMD);
  			mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  			stat = mddi_readl(STAT);
  			printk(KERN_INFO "mddi cmd send rtd: int %x, stat %x, "
  					"rtd val %x\n", mddi_readl(INT), stat,
  					mddi_readl(RTD_VAL));
  			if ((stat & MDDI_STAT_RTD_MEAS_FAIL) == 0)
  				break;
  			msleep(1);
  		}
  
  		mddi_writel(CMD_GET_CLIENT_CAP, CMD);
  		mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  		wait_event_timeout(mddi->int_wait, mddi->flags & FLAG_HAVE_CAPS,
  				   HZ / 100);
  
  		if (mddi->flags & FLAG_HAVE_CAPS)
  			break;
  		printk(KERN_INFO "mddi_init, timeout waiting for caps\n");
  	}
  	return mddi->flags & FLAG_HAVE_CAPS;
  }
  
  /* link must be active when this is called */
  int mddi_check_status(struct mddi_info *mddi)
  {
  	int ret = -1, retry = 3;
  	mutex_lock(&mddi->reg_read_lock);
  	mddi_writel(MDDI_CMD_PERIODIC_REV_ENCAP | 1, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  
  	do {
  		mddi->flags &= ~FLAG_HAVE_STATUS;
  		mddi_writel(CMD_GET_CLIENT_STATUS, CMD);
  		mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  		wait_event_timeout(mddi->int_wait,
  				   mddi->flags & FLAG_HAVE_STATUS,
  				   HZ / 100);
  
  		if (mddi->flags & FLAG_HAVE_STATUS) {
  			if (mddi->status.crc_error_count)
  				printk(KERN_INFO "mddi status: crc_error "
  					"count: %d\n",
  					mddi->status.crc_error_count);
  			else
  				ret = 0;
  			break;
  		} else
  			printk(KERN_INFO "mddi status: failed to get client "
  				"status\n");
  		mddi_writel(MDDI_CMD_SEND_RTD, CMD);
  		mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	} while (--retry);
  
  	mddi_writel(MDDI_CMD_PERIODIC_REV_ENCAP | 0, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	mutex_unlock(&mddi->reg_read_lock);
  	return ret;
  }
  
  
  void mddi_remote_write(struct msm_mddi_client_data *cdata, uint32_t val,
  		       uint32_t reg)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	struct mddi_llentry *ll;
  	struct mddi_register_access *ra;
  
  	mutex_lock(&mddi->reg_write_lock);
  
  	ll = mddi->reg_write_data;
  
  	ra = &(ll->u.r);
  	ra->length = 14 + 4;
  	ra->type = TYPE_REGISTER_ACCESS;
  	ra->client_id = 0;
  	ra->read_write_info = MDDI_WRITE | 1;
  	ra->crc16 = 0;
  
  	ra->register_address = reg;
  	ra->register_data_list = val;
  
  	ll->flags = 1;
  	ll->header_count = 14;
  	ll->data_count = 4;
  	ll->data = mddi->reg_write_addr + offsetof(struct mddi_llentry,
  						   u.r.register_data_list);
  	ll->next = 0;
  	ll->reserved = 0;
  
  	mddi_writel(mddi->reg_write_addr, PRI_PTR);
  
  	mddi_wait_interrupt(mddi, MDDI_INT_PRI_LINK_LIST_DONE);
  	mutex_unlock(&mddi->reg_write_lock);
  }
  
  uint32_t mddi_remote_read(struct msm_mddi_client_data *cdata, uint32_t reg)
  {
  	struct mddi_info *mddi = container_of(cdata, struct mddi_info,
  					      client_data);
  	struct mddi_llentry *ll;
  	struct mddi_register_access *ra;
  	struct reg_read_info ri;
  	unsigned s;
  	int retry_count = 2;
  	unsigned long irq_flags;
  
  	mutex_lock(&mddi->reg_read_lock);
  
  	ll = mddi->reg_read_data;
  
  	ra = &(ll->u.r);
  	ra->length = 14;
  	ra->type = TYPE_REGISTER_ACCESS;
  	ra->client_id = 0;
  	ra->read_write_info = MDDI_READ | 1;
  	ra->crc16 = 0;
  
  	ra->register_address = reg;
  
  	ll->flags = 0x11;
  	ll->header_count = 14;
  	ll->data_count = 0;
  	ll->data = 0;
  	ll->next = 0;
  	ll->reserved = 0;
  
  	s = mddi_readl(STAT);
  
  	ri.reg = reg;
  	ri.status = -1;
  
  	do {
  		init_completion(&ri.done);
  		mddi->reg_read = &ri;
  		mddi_writel(mddi->reg_read_addr, PRI_PTR);
  
  		mddi_wait_interrupt(mddi, MDDI_INT_PRI_LINK_LIST_DONE);
  
  		/* Enable Periodic Reverse Encapsulation. */
  		mddi_writel(MDDI_CMD_PERIODIC_REV_ENCAP | 1, CMD);
  		mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  		if (wait_for_completion_timeout(&ri.done, HZ/10) == 0 &&
  		    !ri.done.done) {
  			printk(KERN_INFO "mddi_remote_read(%x) timeout "
  					 "(%d %d %d)\n",
  			       reg, ri.status, ri.result, ri.done.done);
  			spin_lock_irqsave(&mddi->int_lock, irq_flags);
  			mddi->reg_read = NULL;
  			spin_unlock_irqrestore(&mddi->int_lock, irq_flags);
  			ri.status = -1;
  			ri.result = -1;
  		}
  		if (ri.status == 0)
  			break;
  
  		mddi_writel(MDDI_CMD_SEND_RTD, CMD);
  		mddi_writel(MDDI_CMD_LINK_ACTIVE, CMD);
  		mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  		printk(KERN_INFO "mddi_remote_read: failed, sent "
  		       "MDDI_CMD_SEND_RTD: int %x, stat %x, rtd val %x "
  		       "curr_rev_ptr %x\n", mddi_readl(INT), mddi_readl(STAT),
  		       mddi_readl(RTD_VAL), mddi_readl(CURR_REV_PTR));
  	} while (retry_count-- > 0);
  	/* Disable Periodic Reverse Encapsulation. */
  	mddi_writel(MDDI_CMD_PERIODIC_REV_ENCAP | 0, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	mddi->reg_read = NULL;
  	mutex_unlock(&mddi->reg_read_lock);
  	return ri.result;
  }
  
  static struct mddi_info mddi_info[2];
  
  static int __devinit mddi_clk_setup(struct platform_device *pdev,
  				    struct mddi_info *mddi,
  				    unsigned long clk_rate)
  {
  	int ret;
  
  	/* set up the clocks */
  	mddi->clk = clk_get(&pdev->dev, "mddi_clk");
  	if (IS_ERR(mddi->clk)) {
  		printk(KERN_INFO "mddi: failed to get clock\n");
  		return PTR_ERR(mddi->clk);
  	}
  	ret =  clk_enable(mddi->clk);
  	if (ret)
  		goto fail;
  	ret = clk_set_rate(mddi->clk, clk_rate);
  	if (ret)
  		goto fail;
  	return 0;
  
  fail:
  	clk_put(mddi->clk);
  	return ret;
  }
  
  static int __init mddi_rev_data_setup(struct mddi_info *mddi)
  {
  	void *dma;
  	dma_addr_t dma_addr;
  
  	/* set up dma buffer */
  	dma = dma_alloc_coherent(NULL, 0x1000, &dma_addr, GFP_KERNEL);
  	if (dma == 0)
  		return -ENOMEM;
  	mddi->rev_data = dma;
  	mddi->rev_data_curr = 0;
  	mddi->rev_addr = dma_addr;
  	mddi->reg_write_data = dma + MDDI_REV_BUFFER_SIZE;
  	mddi->reg_write_addr = dma_addr + MDDI_REV_BUFFER_SIZE;
  	mddi->reg_read_data = mddi->reg_write_data + 1;
  	mddi->reg_read_addr = mddi->reg_write_addr +
  			      sizeof(*mddi->reg_write_data);
  	return 0;
  }
  
  static int __devinit mddi_probe(struct platform_device *pdev)
  {
  	struct msm_mddi_platform_data *pdata = pdev->dev.platform_data;
  	struct mddi_info *mddi = &mddi_info[pdev->id];
  	struct resource *resource;
  	int ret, i;
  
  	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!resource) {
  		printk(KERN_ERR "mddi: no associated mem resource!\n");
  		return -ENOMEM;
  	}
  	mddi->base = ioremap(resource->start, resource_size(resource));
  	if (!mddi->base) {
  		printk(KERN_ERR "mddi: failed to remap base!\n");
  		ret = -EINVAL;
  		goto error_ioremap;
  	}
  	resource = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
  	if (!resource) {
  		printk(KERN_ERR "mddi: no associated irq resource!\n");
  		ret = -EINVAL;
  		goto error_get_irq_resource;
  	}
  	mddi->irq = resource->start;
  	printk(KERN_INFO "mddi: init() base=0x%p irq=%d\n", mddi->base,
  	       mddi->irq);
  	mddi->power_client = pdata->power_client;
  
  	mutex_init(&mddi->reg_write_lock);
  	mutex_init(&mddi->reg_read_lock);
  	spin_lock_init(&mddi->int_lock);
  	init_waitqueue_head(&mddi->int_wait);
  
  	ret = mddi_clk_setup(pdev, mddi, pdata->clk_rate);
  	if (ret) {
  		printk(KERN_ERR "mddi: failed to setup clock!\n");
  		goto error_clk_setup;
  	}
  
  	ret = mddi_rev_data_setup(mddi);
  	if (ret) {
  		printk(KERN_ERR "mddi: failed to setup rev data!\n");
  		goto error_rev_data;
  	}
  
  	mddi->int_enable = 0;
  	mddi_writel(mddi->int_enable, INTEN);
  	ret = request_irq(mddi->irq, mddi_isr, 0, "mddi",
  			  &mddi->client_data);
  	if (ret) {
  		printk(KERN_ERR "mddi: failed to request enable irq!\n");
  		goto error_request_irq;
  	}
  
  	/* turn on the mddi client bridge chip */
  	if (mddi->power_client)
  		mddi->power_client(&mddi->client_data, 1);
  
  	/* initialize the mddi registers */
  	mddi_set_auto_hibernate(&mddi->client_data, 0);
  	mddi_writel(MDDI_CMD_RESET, CMD);
  	mddi_wait_interrupt(mddi, MDDI_INT_NO_CMD_PKTS_PEND);
  	mddi->version = mddi_init_registers(mddi);
  	if (mddi->version < 0x20) {
  		printk(KERN_ERR "mddi: unsupported version 0x%x\n",
  		       mddi->version);
  		ret = -ENODEV;
  		goto error_mddi_version;
  	}
  
  	/* read the capabilities off the client */
  	if (!mddi_get_client_caps(mddi)) {
  		printk(KERN_INFO "mddi: no client found\n");
  		/* power down the panel */
  		mddi_writel(MDDI_CMD_POWERDOWN, CMD);
  		printk(KERN_INFO "mddi powerdown: stat %x\n", mddi_readl(STAT));
  		msleep(100);
  		printk(KERN_INFO "mddi powerdown: stat %x\n", mddi_readl(STAT));
  		return 0;
  	}
  	mddi_set_auto_hibernate(&mddi->client_data, 1);
  
  	if (mddi->caps.Mfr_Name == 0 && mddi->caps.Product_Code == 0)
  		pdata->fixup(&mddi->caps.Mfr_Name, &mddi->caps.Product_Code);
  
  	mddi->client_pdev.id = 0;
  	for (i = 0; i < pdata->num_clients; i++) {
  		if (pdata->client_platform_data[i].product_id ==
  		    (mddi->caps.Mfr_Name << 16 | mddi->caps.Product_Code)) {
  			mddi->client_data.private_client_data =
  				pdata->client_platform_data[i].client_data;
  			mddi->client_pdev.name =
  				pdata->client_platform_data[i].name;
  			mddi->client_pdev.id =
  				pdata->client_platform_data[i].id;
  			/* XXX: possibly set clock */
  			break;
  		}
  	}
  
  	if (i >= pdata->num_clients)
  		mddi->client_pdev.name = "mddi_c_dummy";
  	printk(KERN_INFO "mddi: registering panel %s\n",
  		mddi->client_pdev.name);
  
  	mddi->client_data.suspend = mddi_suspend;
  	mddi->client_data.resume = mddi_resume;
  	mddi->client_data.activate_link = mddi_activate_link;
  	mddi->client_data.remote_write = mddi_remote_write;
  	mddi->client_data.remote_read = mddi_remote_read;
  	mddi->client_data.auto_hibernate = mddi_set_auto_hibernate;
  	mddi->client_data.fb_resource = pdata->fb_resource;
  	if (pdev->id == 0)
  		mddi->client_data.interface_type = MSM_MDDI_PMDH_INTERFACE;
  	else if (pdev->id == 1)
  		mddi->client_data.interface_type = MSM_MDDI_EMDH_INTERFACE;
  	else {
  		printk(KERN_ERR "mddi: can not determine interface %d!\n",
  		       pdev->id);
  		ret = -EINVAL;
  		goto error_mddi_interface;
  	}
  
  	mddi->client_pdev.dev.platform_data = &mddi->client_data;
  	printk(KERN_INFO "mddi: publish: %s\n", mddi->client_name);
  	platform_device_register(&mddi->client_pdev);
  	return 0;
  
  error_mddi_interface:
  error_mddi_version:
  	free_irq(mddi->irq, 0);
  error_request_irq:
  	dma_free_coherent(NULL, 0x1000, mddi->rev_data, mddi->rev_addr);
  error_rev_data:
  error_clk_setup:
  error_get_irq_resource:
  	iounmap(mddi->base);
  error_ioremap:
  
  	printk(KERN_INFO "mddi: mddi_init() failed (%d)\n", ret);
  	return ret;
  }
  
  
  static struct platform_driver mddi_driver = {
  	.probe = mddi_probe,
  	.driver = { .name = "msm_mddi" },
  };
  
  static int __init _mddi_init(void)
  {
  	return platform_driver_register(&mddi_driver);
  }
  
  module_init(_mddi_init);
  