#include <linux/wait.h>
 #include "internal.h"
 
+/* Setup RDDM vector table for RDDM transfer and program RXVEC */
+void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
+                     struct image_info *img_info)
+{
+       struct mhi_buf *mhi_buf = img_info->mhi_buf;
+       struct bhi_vec_entry *bhi_vec = img_info->bhi_vec;
+       void __iomem *base = mhi_cntrl->bhie;
+       struct device *dev = &mhi_cntrl->mhi_dev->dev;
+       u32 sequence_id;
+       unsigned int i;
+
+       for (i = 0; i < img_info->entries - 1; i++, mhi_buf++, bhi_vec++) {
+               bhi_vec->dma_addr = mhi_buf->dma_addr;
+               bhi_vec->size = mhi_buf->len;
+       }
+
+       dev_dbg(dev, "BHIe programming for RDDM\n");
+
+       mhi_write_reg(mhi_cntrl, base, BHIE_RXVECADDR_HIGH_OFFS,
+                     upper_32_bits(mhi_buf->dma_addr));
+
+       mhi_write_reg(mhi_cntrl, base, BHIE_RXVECADDR_LOW_OFFS,
+                     lower_32_bits(mhi_buf->dma_addr));
+
+       mhi_write_reg(mhi_cntrl, base, BHIE_RXVECSIZE_OFFS, mhi_buf->len);
+       sequence_id = prandom_u32() & BHIE_RXVECSTATUS_SEQNUM_BMSK;
+
+       if (unlikely(!sequence_id))
+               sequence_id = 1;
+
+       mhi_write_reg_field(mhi_cntrl, base, BHIE_RXVECDB_OFFS,
+                           BHIE_RXVECDB_SEQNUM_BMSK, BHIE_RXVECDB_SEQNUM_SHFT,
+                           sequence_id);
+
+       dev_dbg(dev, "Address: %p and len: 0x%lx sequence: %u\n",
+               &mhi_buf->dma_addr, mhi_buf->len, sequence_id);
+}
+
+/* Collect RDDM buffer during kernel panic */
+static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
+{
+       int ret;
+       u32 rx_status;
+       enum mhi_ee_type ee;
+       const u32 delayus = 2000;
+       u32 retry = (mhi_cntrl->timeout_ms * 1000) / delayus;
+       const u32 rddm_timeout_us = 200000;
+       int rddm_retry = rddm_timeout_us / delayus;
+       void __iomem *base = mhi_cntrl->bhie;
+       struct device *dev = &mhi_cntrl->mhi_dev->dev;
+
+       dev_dbg(dev, "Entered with pm_state:%s dev_state:%s ee:%s\n",
+               to_mhi_pm_state_str(mhi_cntrl->pm_state),
+               TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+               TO_MHI_EXEC_STR(mhi_cntrl->ee));
+
+       /*
+        * This should only be executing during a kernel panic, we expect all
+        * other cores to shutdown while we're collecting RDDM buffer. After
+        * returning from this function, we expect the device to reset.
+        *
+        * Normaly, we read/write pm_state only after grabbing the
+        * pm_lock, since we're in a panic, skipping it. Also there is no
+        * gurantee that this state change would take effect since
+        * we're setting it w/o grabbing pm_lock
+        */
+       mhi_cntrl->pm_state = MHI_PM_LD_ERR_FATAL_DETECT;
+       /* update should take the effect immediately */
+       smp_wmb();
+
+       /*
+        * Make sure device is not already in RDDM. In case the device asserts
+        * and a kernel panic follows, device will already be in RDDM.
+        * Do not trigger SYS ERR again and proceed with waiting for
+        * image download completion.
+        */
+       ee = mhi_get_exec_env(mhi_cntrl);
+       if (ee != MHI_EE_RDDM) {
+               dev_dbg(dev, "Trigger device into RDDM mode using SYS ERR\n");
+               mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);
+
+               dev_dbg(dev, "Waiting for device to enter RDDM\n");
+               while (rddm_retry--) {
+                       ee = mhi_get_exec_env(mhi_cntrl);
+                       if (ee == MHI_EE_RDDM)
+                               break;
+
+                       udelay(delayus);
+               }
+
+               if (rddm_retry <= 0) {
+                       /* Hardware reset so force device to enter RDDM */
+                       dev_dbg(dev,
+                               "Did not enter RDDM, do a host req reset\n");
+                       mhi_write_reg(mhi_cntrl, mhi_cntrl->regs,
+                                     MHI_SOC_RESET_REQ_OFFSET,
+                                     MHI_SOC_RESET_REQ);
+                       udelay(delayus);
+               }
+
+               ee = mhi_get_exec_env(mhi_cntrl);
+       }
+
+       dev_dbg(dev, "Waiting for image download completion, current EE: %s\n",
+               TO_MHI_EXEC_STR(ee));
+
+       while (retry--) {
+               ret = mhi_read_reg_field(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS,
+                                        BHIE_RXVECSTATUS_STATUS_BMSK,
+                                        BHIE_RXVECSTATUS_STATUS_SHFT,
+                                        &rx_status);
+               if (ret)
+                       return -EIO;
+
+               if (rx_status == BHIE_RXVECSTATUS_STATUS_XFER_COMPL)
+                       return 0;
+
+               udelay(delayus);
+       }
+
+       ee = mhi_get_exec_env(mhi_cntrl);
+       ret = mhi_read_reg(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS, &rx_status);
+
+       dev_err(dev, "Did not complete RDDM transfer\n");
+       dev_err(dev, "Current EE: %s\n", TO_MHI_EXEC_STR(ee));
+       dev_err(dev, "RXVEC_STATUS: 0x%x\n", rx_status);
+
+       return -EIO;
+}
+
+/* Download RDDM image from device */
+int mhi_download_rddm_img(struct mhi_controller *mhi_cntrl, bool in_panic)
+{
+       void __iomem *base = mhi_cntrl->bhie;
+       u32 rx_status;
+
+       if (in_panic)
+               return __mhi_download_rddm_in_panic(mhi_cntrl);
+
+       /* Wait for the image download to complete */
+       wait_event_timeout(mhi_cntrl->state_event,
+                          mhi_read_reg_field(mhi_cntrl, base,
+                                             BHIE_RXVECSTATUS_OFFS,
+                                             BHIE_RXVECSTATUS_STATUS_BMSK,
+                                             BHIE_RXVECSTATUS_STATUS_SHFT,
+                                             &rx_status) || rx_status,
+                          msecs_to_jiffies(mhi_cntrl->timeout_ms));
+
+       return (rx_status == BHIE_RXVECSTATUS_STATUS_XFER_COMPL) ? 0 : -EIO;
+}
+EXPORT_SYMBOL_GPL(mhi_download_rddm_img);
+
 static int mhi_fw_load_amss(struct mhi_controller *mhi_cntrl,
                            const struct mhi_buf *mhi_buf)
 {
 
 
 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 {
+       struct device *dev = &mhi_cntrl->mhi_dev->dev;
+       u32 bhie_off;
        int ret;
 
        mutex_lock(&mhi_cntrl->pm_mutex);
        if (ret)
                goto error_dev_ctxt;
 
+       /*
+        * Allocate RDDM table if specified, this table is for debugging purpose
+        */
+       if (mhi_cntrl->rddm_size) {
+               mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
+                                    mhi_cntrl->rddm_size);
+
+               /*
+                * This controller supports RDDM, so we need to manually clear
+                * BHIE RX registers since POR values are undefined.
+                */
+               ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
+                                  &bhie_off);
+               if (ret) {
+                       dev_err(dev, "Error getting BHIE offset\n");
+                       goto bhie_error;
+               }
+
+               memset_io(mhi_cntrl->regs + bhie_off + BHIE_RXVECADDR_LOW_OFFS,
+                         0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
+                         4);
+
+               if (mhi_cntrl->rddm_image)
+                       mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
+       }
+
        mhi_cntrl->pre_init = true;
 
        mutex_unlock(&mhi_cntrl->pm_mutex);
 
        return 0;
 
+bhie_error:
+       if (mhi_cntrl->rddm_image) {
+               mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
+               mhi_cntrl->rddm_image = NULL;
+       }
+
 error_dev_ctxt:
        mutex_unlock(&mhi_cntrl->pm_mutex);
 
                mhi_cntrl->fbc_image = NULL;
        }
 
+       if (mhi_cntrl->rddm_image) {
+               mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
+               mhi_cntrl->rddm_image = NULL;
+       }
+
        mhi_deinit_dev_ctxt(mhi_cntrl);
        mhi_cntrl->pre_init = false;
 }
 
 
        /* We must notify MHI control driver so it can clean up first */
        if (transition_state == MHI_PM_SYS_ERR_PROCESS) {
+               /*
+                * If controller supports RDDM, we do not process
+                * SYS error state, instead we will jump directly
+                * to RDDM state
+                */
+               if (mhi_cntrl->rddm_image) {
+                       dev_dbg(dev,
+                                "Controller supports RDDM, so skip SYS_ERR\n");
+                       return;
+               }
                mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR);
        }
 
        return (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -EIO;
 }
 EXPORT_SYMBOL(mhi_sync_power_up);
+
+int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl)
+{
+       struct device *dev = &mhi_cntrl->mhi_dev->dev;
+       int ret;
+
+       /* Check if device is already in RDDM */
+       if (mhi_cntrl->ee == MHI_EE_RDDM)
+               return 0;
+
+       dev_dbg(dev, "Triggering SYS_ERR to force RDDM state\n");
+       mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);
+
+       /* Wait for RDDM event */
+       ret = wait_event_timeout(mhi_cntrl->state_event,
+                                mhi_cntrl->ee == MHI_EE_RDDM,
+                                msecs_to_jiffies(mhi_cntrl->timeout_ms));
+       ret = ret ? 0 : -EIO;
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_force_rddm_mode);
 
  * @iova_stop: IOMMU stop address for data (required)
  * @fw_image: Firmware image name for normal booting (required)
  * @edl_image: Firmware image name for emergency download mode (optional)
+ * @rddm_size: RAM dump size that host should allocate for debugging purpose
  * @sbl_size: SBL image size downloaded through BHIe (optional)
  * @seg_len: BHIe vector size (optional)
  * @fbc_image: Points to firmware image buffer
+ * @rddm_image: Points to RAM dump buffer
  * @mhi_chan: Points to the channel configuration table
  * @lpm_chans: List of channels that require LPM notifications
  * @irq: base irq # to request (required)
        dma_addr_t iova_stop;
        const char *fw_image;
        const char *edl_image;
+       size_t rddm_size;
        size_t sbl_size;
        size_t seg_len;
        struct image_info *fbc_image;
+       struct image_info *rddm_image;
        struct mhi_chan *mhi_chan;
        struct list_head lpm_chans;
        int *irq;
  */
 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl);
 
+/**
+ * mhi_download_rddm_img - Download ramdump image from device for
+ *                         debugging purpose.
+ * @mhi_cntrl: MHI controller
+ * @in_panic: Download rddm image during kernel panic
+ */
+int mhi_download_rddm_img(struct mhi_controller *mhi_cntrl, bool in_panic);
+
+/**
+ * mhi_force_rddm_mode - Force device into rddm mode
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl);
+
+/**
+ * mhi_get_mhi_state - Get MHI state of the device
+ * @mhi_cntrl: MHI controller
+ */
+enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl);
+
 #endif /* _MHI_H_ */