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Diffstat (limited to 'drivers/bus/mhi/core/main.c')
-rw-r--r--drivers/bus/mhi/core/main.c1529
1 files changed, 1529 insertions, 0 deletions
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
new file mode 100644
index 000000000000..eb4256b81406
--- /dev/null
+++ b/drivers/bus/mhi/core/main.c
@@ -0,0 +1,1529 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl,
+ void __iomem *base, u32 offset, u32 *out)
+{
+ u32 tmp = readl(base + offset);
+
+ /* If there is any unexpected value, query the link status */
+ if (PCI_INVALID_READ(tmp) &&
+ mhi_cntrl->link_status(mhi_cntrl))
+ return -EIO;
+
+ *out = tmp;
+
+ return 0;
+}
+
+int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl,
+ void __iomem *base, u32 offset,
+ u32 mask, u32 shift, u32 *out)
+{
+ u32 tmp;
+ int ret;
+
+ ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
+ if (ret)
+ return ret;
+
+ *out = (tmp & mask) >> shift;
+
+ return 0;
+}
+
+void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base,
+ u32 offset, u32 val)
+{
+ writel(val, base + offset);
+}
+
+void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base,
+ u32 offset, u32 mask, u32 shift, u32 val)
+{
+ int ret;
+ u32 tmp;
+
+ ret = mhi_read_reg(mhi_cntrl, base, offset, &tmp);
+ if (ret)
+ return;
+
+ tmp &= ~mask;
+ tmp |= (val << shift);
+ mhi_write_reg(mhi_cntrl, base, offset, tmp);
+}
+
+void mhi_write_db(struct mhi_controller *mhi_cntrl, void __iomem *db_addr,
+ dma_addr_t db_val)
+{
+ mhi_write_reg(mhi_cntrl, db_addr, 4, upper_32_bits(db_val));
+ mhi_write_reg(mhi_cntrl, db_addr, 0, lower_32_bits(db_val));
+}
+
+void mhi_db_brstmode(struct mhi_controller *mhi_cntrl,
+ struct db_cfg *db_cfg,
+ void __iomem *db_addr,
+ dma_addr_t db_val)
+{
+ if (db_cfg->db_mode) {
+ db_cfg->db_val = db_val;
+ mhi_write_db(mhi_cntrl, db_addr, db_val);
+ db_cfg->db_mode = 0;
+ }
+}
+
+void mhi_db_brstmode_disable(struct mhi_controller *mhi_cntrl,
+ struct db_cfg *db_cfg,
+ void __iomem *db_addr,
+ dma_addr_t db_val)
+{
+ db_cfg->db_val = db_val;
+ mhi_write_db(mhi_cntrl, db_addr, db_val);
+}
+
+void mhi_ring_er_db(struct mhi_event *mhi_event)
+{
+ struct mhi_ring *ring = &mhi_event->ring;
+
+ mhi_event->db_cfg.process_db(mhi_event->mhi_cntrl, &mhi_event->db_cfg,
+ ring->db_addr, *ring->ctxt_wp);
+}
+
+void mhi_ring_cmd_db(struct mhi_controller *mhi_cntrl, struct mhi_cmd *mhi_cmd)
+{
+ dma_addr_t db;
+ struct mhi_ring *ring = &mhi_cmd->ring;
+
+ db = ring->iommu_base + (ring->wp - ring->base);
+ *ring->ctxt_wp = db;
+ mhi_write_db(mhi_cntrl, ring->db_addr, db);
+}
+
+void mhi_ring_chan_db(struct mhi_controller *mhi_cntrl,
+ struct mhi_chan *mhi_chan)
+{
+ struct mhi_ring *ring = &mhi_chan->tre_ring;
+ dma_addr_t db;
+
+ db = ring->iommu_base + (ring->wp - ring->base);
+ *ring->ctxt_wp = db;
+ mhi_chan->db_cfg.process_db(mhi_cntrl, &mhi_chan->db_cfg,
+ ring->db_addr, db);
+}
+
+enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl)
+{
+ u32 exec;
+ int ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_EXECENV, &exec);
+
+ return (ret) ? MHI_EE_MAX : exec;
+}
+
+enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl)
+{
+ u32 state;
+ int ret = mhi_read_reg_field(mhi_cntrl, mhi_cntrl->regs, MHISTATUS,
+ MHISTATUS_MHISTATE_MASK,
+ MHISTATUS_MHISTATE_SHIFT, &state);
+ return ret ? MHI_STATE_MAX : state;
+}
+
+int mhi_map_single_no_bb(struct mhi_controller *mhi_cntrl,
+ struct mhi_buf_info *buf_info)
+{
+ buf_info->p_addr = dma_map_single(mhi_cntrl->cntrl_dev,
+ buf_info->v_addr, buf_info->len,
+ buf_info->dir);
+ if (dma_mapping_error(mhi_cntrl->cntrl_dev, buf_info->p_addr))
+ return -ENOMEM;
+
+ return 0;
+}
+
+int mhi_map_single_use_bb(struct mhi_controller *mhi_cntrl,
+ struct mhi_buf_info *buf_info)
+{
+ void *buf = mhi_alloc_coherent(mhi_cntrl, buf_info->len,
+ &buf_info->p_addr, GFP_ATOMIC);
+
+ if (!buf)
+ return -ENOMEM;
+
+ if (buf_info->dir == DMA_TO_DEVICE)
+ memcpy(buf, buf_info->v_addr, buf_info->len);
+
+ buf_info->bb_addr = buf;
+
+ return 0;
+}
+
+void mhi_unmap_single_no_bb(struct mhi_controller *mhi_cntrl,
+ struct mhi_buf_info *buf_info)
+{
+ dma_unmap_single(mhi_cntrl->cntrl_dev, buf_info->p_addr, buf_info->len,
+ buf_info->dir);
+}
+
+void mhi_unmap_single_use_bb(struct mhi_controller *mhi_cntrl,
+ struct mhi_buf_info *buf_info)
+{
+ if (buf_info->dir == DMA_FROM_DEVICE)
+ memcpy(buf_info->v_addr, buf_info->bb_addr, buf_info->len);
+
+ mhi_free_coherent(mhi_cntrl, buf_info->len, buf_info->bb_addr,
+ buf_info->p_addr);
+}
+
+static int get_nr_avail_ring_elements(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring)
+{
+ int nr_el;
+
+ if (ring->wp < ring->rp) {
+ nr_el = ((ring->rp - ring->wp) / ring->el_size) - 1;
+ } else {
+ nr_el = (ring->rp - ring->base) / ring->el_size;
+ nr_el += ((ring->base + ring->len - ring->wp) /
+ ring->el_size) - 1;
+ }
+
+ return nr_el;
+}
+
+static void *mhi_to_virtual(struct mhi_ring *ring, dma_addr_t addr)
+{
+ return (addr - ring->iommu_base) + ring->base;
+}
+
+static void mhi_add_ring_element(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring)
+{
+ ring->wp += ring->el_size;
+ if (ring->wp >= (ring->base + ring->len))
+ ring->wp = ring->base;
+ /* smp update */
+ smp_wmb();
+}
+
+static void mhi_del_ring_element(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring)
+{
+ ring->rp += ring->el_size;
+ if (ring->rp >= (ring->base + ring->len))
+ ring->rp = ring->base;
+ /* smp update */
+ smp_wmb();
+}
+
+int mhi_destroy_device(struct device *dev, void *data)
+{
+ struct mhi_device *mhi_dev;
+ struct mhi_controller *mhi_cntrl;
+
+ if (dev->bus != &mhi_bus_type)
+ return 0;
+
+ mhi_dev = to_mhi_device(dev);
+ mhi_cntrl = mhi_dev->mhi_cntrl;
+
+ /* Only destroy virtual devices thats attached to bus */
+ if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
+ return 0;
+
+ /*
+ * For the suspend and resume case, this function will get called
+ * without mhi_unregister_controller(). Hence, we need to drop the
+ * references to mhi_dev created for ul and dl channels. We can
+ * be sure that there will be no instances of mhi_dev left after
+ * this.
+ */
+ if (mhi_dev->ul_chan)
+ put_device(&mhi_dev->ul_chan->mhi_dev->dev);
+
+ if (mhi_dev->dl_chan)
+ put_device(&mhi_dev->dl_chan->mhi_dev->dev);
+
+ dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
+ mhi_dev->chan_name);
+
+ /* Notify the client and remove the device from MHI bus */
+ device_del(dev);
+ put_device(dev);
+
+ return 0;
+}
+
+static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
+{
+ struct mhi_driver *mhi_drv;
+
+ if (!mhi_dev->dev.driver)
+ return;
+
+ mhi_drv = to_mhi_driver(mhi_dev->dev.driver);
+
+ if (mhi_drv->status_cb)
+ mhi_drv->status_cb(mhi_dev, cb_reason);
+}
+
+/* Bind MHI channels to MHI devices */
+void mhi_create_devices(struct mhi_controller *mhi_cntrl)
+{
+ struct mhi_chan *mhi_chan;
+ struct mhi_device *mhi_dev;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ int i, ret;
+
+ mhi_chan = mhi_cntrl->mhi_chan;
+ for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
+ if (!mhi_chan->configured || mhi_chan->mhi_dev ||
+ !(mhi_chan->ee_mask & BIT(mhi_cntrl->ee)))
+ continue;
+ mhi_dev = mhi_alloc_device(mhi_cntrl);
+ if (!mhi_dev)
+ return;
+
+ mhi_dev->dev_type = MHI_DEVICE_XFER;
+ switch (mhi_chan->dir) {
+ case DMA_TO_DEVICE:
+ mhi_dev->ul_chan = mhi_chan;
+ mhi_dev->ul_chan_id = mhi_chan->chan;
+ break;
+ case DMA_FROM_DEVICE:
+ /* We use dl_chan as offload channels */
+ mhi_dev->dl_chan = mhi_chan;
+ mhi_dev->dl_chan_id = mhi_chan->chan;
+ break;
+ default:
+ dev_err(dev, "Direction not supported\n");
+ put_device(&mhi_dev->dev);
+ return;
+ }
+
+ get_device(&mhi_dev->dev);
+ mhi_chan->mhi_dev = mhi_dev;
+
+ /* Check next channel if it matches */
+ if ((i + 1) < mhi_cntrl->max_chan && mhi_chan[1].configured) {
+ if (!strcmp(mhi_chan[1].name, mhi_chan->name)) {
+ i++;
+ mhi_chan++;
+ if (mhi_chan->dir == DMA_TO_DEVICE) {
+ mhi_dev->ul_chan = mhi_chan;
+ mhi_dev->ul_chan_id = mhi_chan->chan;
+ } else {
+ mhi_dev->dl_chan = mhi_chan;
+ mhi_dev->dl_chan_id = mhi_chan->chan;
+ }
+ get_device(&mhi_dev->dev);
+ mhi_chan->mhi_dev = mhi_dev;
+ }
+ }
+
+ /* Channel name is same for both UL and DL */
+ mhi_dev->chan_name = mhi_chan->name;
+ dev_set_name(&mhi_dev->dev, "%04x_%s", mhi_chan->chan,
+ mhi_dev->chan_name);
+
+ /* Init wakeup source if available */
+ if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
+ device_init_wakeup(&mhi_dev->dev, true);
+
+ ret = device_add(&mhi_dev->dev);
+ if (ret)
+ put_device(&mhi_dev->dev);
+ }
+}
+
+irqreturn_t mhi_irq_handler(int irq_number, void *dev)
+{
+ struct mhi_event *mhi_event = dev;
+ struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
+ struct mhi_event_ctxt *er_ctxt =
+ &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
+ struct mhi_ring *ev_ring = &mhi_event->ring;
+ void *dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+
+ /* Only proceed if event ring has pending events */
+ if (ev_ring->rp == dev_rp)
+ return IRQ_HANDLED;
+
+ /* For client managed event ring, notify pending data */
+ if (mhi_event->cl_manage) {
+ struct mhi_chan *mhi_chan = mhi_event->mhi_chan;
+ struct mhi_device *mhi_dev = mhi_chan->mhi_dev;
+
+ if (mhi_dev)
+ mhi_notify(mhi_dev, MHI_CB_PENDING_DATA);
+ } else {
+ tasklet_schedule(&mhi_event->task);
+ }
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *dev)
+{
+ struct mhi_controller *mhi_cntrl = dev;
+ enum mhi_state state = MHI_STATE_MAX;
+ enum mhi_pm_state pm_state = 0;
+ enum mhi_ee_type ee = 0;
+
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
+ state = mhi_get_mhi_state(mhi_cntrl);
+ ee = mhi_cntrl->ee;
+ mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
+ }
+
+ if (state == MHI_STATE_SYS_ERR) {
+ dev_dbg(&mhi_cntrl->mhi_dev->dev, "System error detected\n");
+ pm_state = mhi_tryset_pm_state(mhi_cntrl,
+ MHI_PM_SYS_ERR_DETECT);
+ }
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+
+ /* If device in RDDM don't bother processing SYS error */
+ if (mhi_cntrl->ee == MHI_EE_RDDM) {
+ if (mhi_cntrl->ee != ee) {
+ mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
+ wake_up_all(&mhi_cntrl->state_event);
+ }
+ goto exit_intvec;
+ }
+
+ if (pm_state == MHI_PM_SYS_ERR_DETECT) {
+ wake_up_all(&mhi_cntrl->state_event);
+
+ /* For fatal errors, we let controller decide next step */
+ if (MHI_IN_PBL(ee))
+ mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_FATAL_ERROR);
+ else
+ schedule_work(&mhi_cntrl->syserr_worker);
+ }
+
+exit_intvec:
+
+ return IRQ_HANDLED;
+}
+
+irqreturn_t mhi_intvec_handler(int irq_number, void *dev)
+{
+ struct mhi_controller *mhi_cntrl = dev;
+
+ /* Wake up events waiting for state change */
+ wake_up_all(&mhi_cntrl->state_event);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static void mhi_recycle_ev_ring_element(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring)
+{
+ dma_addr_t ctxt_wp;
+
+ /* Update the WP */
+ ring->wp += ring->el_size;
+ ctxt_wp = *ring->ctxt_wp + ring->el_size;
+
+ if (ring->wp >= (ring->base + ring->len)) {
+ ring->wp = ring->base;
+ ctxt_wp = ring->iommu_base;
+ }
+
+ *ring->ctxt_wp = ctxt_wp;
+
+ /* Update the RP */
+ ring->rp += ring->el_size;
+ if (ring->rp >= (ring->base + ring->len))
+ ring->rp = ring->base;
+
+ /* Update to all cores */
+ smp_wmb();
+}
+
+static int parse_xfer_event(struct mhi_controller *mhi_cntrl,
+ struct mhi_tre *event,
+ struct mhi_chan *mhi_chan)
+{
+ struct mhi_ring *buf_ring, *tre_ring;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ struct mhi_result result;
+ unsigned long flags = 0;
+ u32 ev_code;
+
+ ev_code = MHI_TRE_GET_EV_CODE(event);
+ buf_ring = &mhi_chan->buf_ring;
+ tre_ring = &mhi_chan->tre_ring;
+
+ result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
+ -EOVERFLOW : 0;
+
+ /*
+ * If it's a DB Event then we need to grab the lock
+ * with preemption disabled and as a write because we
+ * have to update db register and there are chances that
+ * another thread could be doing the same.
+ */
+ if (ev_code >= MHI_EV_CC_OOB)
+ write_lock_irqsave(&mhi_chan->lock, flags);
+ else
+ read_lock_bh(&mhi_chan->lock);
+
+ if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
+ goto end_process_tx_event;
+
+ switch (ev_code) {
+ case MHI_EV_CC_OVERFLOW:
+ case MHI_EV_CC_EOB:
+ case MHI_EV_CC_EOT:
+ {
+ dma_addr_t ptr = MHI_TRE_GET_EV_PTR(event);
+ struct mhi_tre *local_rp, *ev_tre;
+ void *dev_rp;
+ struct mhi_buf_info *buf_info;
+ u16 xfer_len;
+
+ /* Get the TRB this event points to */
+ ev_tre = mhi_to_virtual(tre_ring, ptr);
+
+ dev_rp = ev_tre + 1;
+ if (dev_rp >= (tre_ring->base + tre_ring->len))
+ dev_rp = tre_ring->base;
+
+ result.dir = mhi_chan->dir;
+
+ local_rp = tre_ring->rp;
+ while (local_rp != dev_rp) {
+ buf_info = buf_ring->rp;
+ /* If it's the last TRE, get length from the event */
+ if (local_rp == ev_tre)
+ xfer_len = MHI_TRE_GET_EV_LEN(event);
+ else
+ xfer_len = buf_info->len;
+
+ /* Unmap if it's not pre-mapped by client */
+ if (likely(!buf_info->pre_mapped))
+ mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
+
+ result.buf_addr = buf_info->cb_buf;
+ result.bytes_xferd = xfer_len;
+ mhi_del_ring_element(mhi_cntrl, buf_ring);
+ mhi_del_ring_element(mhi_cntrl, tre_ring);
+ local_rp = tre_ring->rp;
+
+ /* notify client */
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+
+ if (mhi_chan->dir == DMA_TO_DEVICE)
+ atomic_dec(&mhi_cntrl->pending_pkts);
+
+ /*
+ * Recycle the buffer if buffer is pre-allocated,
+ * if there is an error, not much we can do apart
+ * from dropping the packet
+ */
+ if (mhi_chan->pre_alloc) {
+ if (mhi_queue_buf(mhi_chan->mhi_dev,
+ mhi_chan->dir,
+ buf_info->cb_buf,
+ buf_info->len, MHI_EOT)) {
+ dev_err(dev,
+ "Error recycling buffer for chan:%d\n",
+ mhi_chan->chan);
+ kfree(buf_info->cb_buf);
+ }
+ }
+ }
+ break;
+ } /* CC_EOT */
+ case MHI_EV_CC_OOB:
+ case MHI_EV_CC_DB_MODE:
+ {
+ unsigned long flags;
+
+ mhi_chan->db_cfg.db_mode = 1;
+ read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
+ if (tre_ring->wp != tre_ring->rp &&
+ MHI_DB_ACCESS_VALID(mhi_cntrl)) {
+ mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+ }
+ read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
+ break;
+ }
+ case MHI_EV_CC_BAD_TRE:
+ default:
+ dev_err(dev, "Unknown event 0x%x\n", ev_code);
+ break;
+ } /* switch(MHI_EV_READ_CODE(EV_TRB_CODE,event)) */
+
+end_process_tx_event:
+ if (ev_code >= MHI_EV_CC_OOB)
+ write_unlock_irqrestore(&mhi_chan->lock, flags);
+ else
+ read_unlock_bh(&mhi_chan->lock);
+
+ return 0;
+}
+
+static int parse_rsc_event(struct mhi_controller *mhi_cntrl,
+ struct mhi_tre *event,
+ struct mhi_chan *mhi_chan)
+{
+ struct mhi_ring *buf_ring, *tre_ring;
+ struct mhi_buf_info *buf_info;
+ struct mhi_result result;
+ int ev_code;
+ u32 cookie; /* offset to local descriptor */
+ u16 xfer_len;
+
+ buf_ring = &mhi_chan->buf_ring;
+ tre_ring = &mhi_chan->tre_ring;
+
+ ev_code = MHI_TRE_GET_EV_CODE(event);
+ cookie = MHI_TRE_GET_EV_COOKIE(event);
+ xfer_len = MHI_TRE_GET_EV_LEN(event);
+
+ /* Received out of bound cookie */
+ WARN_ON(cookie >= buf_ring->len);
+
+ buf_info = buf_ring->base + cookie;
+
+ result.transaction_status = (ev_code == MHI_EV_CC_OVERFLOW) ?
+ -EOVERFLOW : 0;
+ result.bytes_xferd = xfer_len;
+ result.buf_addr = buf_info->cb_buf;
+ result.dir = mhi_chan->dir;
+
+ read_lock_bh(&mhi_chan->lock);
+
+ if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED)
+ goto end_process_rsc_event;
+
+ WARN_ON(!buf_info->used);
+
+ /* notify the client */
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+
+ /*
+ * Note: We're arbitrarily incrementing RP even though, completion
+ * packet we processed might not be the same one, reason we can do this
+ * is because device guaranteed to cache descriptors in order it
+ * receive, so even though completion event is different we can re-use
+ * all descriptors in between.
+ * Example:
+ * Transfer Ring has descriptors: A, B, C, D
+ * Last descriptor host queue is D (WP) and first descriptor
+ * host queue is A (RP).
+ * The completion event we just serviced is descriptor C.
+ * Then we can safely queue descriptors to replace A, B, and C
+ * even though host did not receive any completions.
+ */
+ mhi_del_ring_element(mhi_cntrl, tre_ring);
+ buf_info->used = false;
+
+end_process_rsc_event:
+ read_unlock_bh(&mhi_chan->lock);
+
+ return 0;
+}
+
+static void mhi_process_cmd_completion(struct mhi_controller *mhi_cntrl,
+ struct mhi_tre *tre)
+{
+ dma_addr_t ptr = MHI_TRE_GET_EV_PTR(tre);
+ struct mhi_cmd *cmd_ring = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
+ struct mhi_ring *mhi_ring = &cmd_ring->ring;
+ struct mhi_tre *cmd_pkt;
+ struct mhi_chan *mhi_chan;
+ u32 chan;
+
+ cmd_pkt = mhi_to_virtual(mhi_ring, ptr);
+
+ chan = MHI_TRE_GET_CMD_CHID(cmd_pkt);
+ mhi_chan = &mhi_cntrl->mhi_chan[chan];
+ write_lock_bh(&mhi_chan->lock);
+ mhi_chan->ccs = MHI_TRE_GET_EV_CODE(tre);
+ complete(&mhi_chan->completion);
+ write_unlock_bh(&mhi_chan->lock);
+
+ mhi_del_ring_element(mhi_cntrl, mhi_ring);
+}
+
+int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
+ struct mhi_event *mhi_event,
+ u32 event_quota)
+{
+ struct mhi_tre *dev_rp, *local_rp;
+ struct mhi_ring *ev_ring = &mhi_event->ring;
+ struct mhi_event_ctxt *er_ctxt =
+ &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
+ struct mhi_chan *mhi_chan;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ u32 chan;
+ int count = 0;
+
+ /*
+ * This is a quick check to avoid unnecessary event processing
+ * in case MHI is already in error state, but it's still possible
+ * to transition to error state while processing events
+ */
+ if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
+ return -EIO;
+
+ dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+ local_rp = ev_ring->rp;
+
+ while (dev_rp != local_rp) {
+ enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
+
+ switch (type) {
+ case MHI_PKT_TYPE_BW_REQ_EVENT:
+ {
+ struct mhi_link_info *link_info;
+
+ link_info = &mhi_cntrl->mhi_link_info;
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ link_info->target_link_speed =
+ MHI_TRE_GET_EV_LINKSPEED(local_rp);
+ link_info->target_link_width =
+ MHI_TRE_GET_EV_LINKWIDTH(local_rp);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ dev_dbg(dev, "Received BW_REQ event\n");
+ mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_BW_REQ);
+ break;
+ }
+ case MHI_PKT_TYPE_STATE_CHANGE_EVENT:
+ {
+ enum mhi_state new_state;
+
+ new_state = MHI_TRE_GET_EV_STATE(local_rp);
+
+ dev_dbg(dev, "State change event to state: %s\n",
+ TO_MHI_STATE_STR(new_state));
+
+ switch (new_state) {
+ case MHI_STATE_M0:
+ mhi_pm_m0_transition(mhi_cntrl);
+ break;
+ case MHI_STATE_M1:
+ mhi_pm_m1_transition(mhi_cntrl);
+ break;
+ case MHI_STATE_M3:
+ mhi_pm_m3_transition(mhi_cntrl);
+ break;
+ case MHI_STATE_SYS_ERR:
+ {
+ enum mhi_pm_state new_state;
+
+ dev_dbg(dev, "System error detected\n");
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ new_state = mhi_tryset_pm_state(mhi_cntrl,
+ MHI_PM_SYS_ERR_DETECT);
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ if (new_state == MHI_PM_SYS_ERR_DETECT)
+ schedule_work(&mhi_cntrl->syserr_worker);
+ break;
+ }
+ default:
+ dev_err(dev, "Invalid state: %s\n",
+ TO_MHI_STATE_STR(new_state));
+ }
+
+ break;
+ }
+ case MHI_PKT_TYPE_CMD_COMPLETION_EVENT:
+ mhi_process_cmd_completion(mhi_cntrl, local_rp);
+ break;
+ case MHI_PKT_TYPE_EE_EVENT:
+ {
+ enum dev_st_transition st = DEV_ST_TRANSITION_MAX;
+ enum mhi_ee_type event = MHI_TRE_GET_EV_EXECENV(local_rp);
+
+ dev_dbg(dev, "Received EE event: %s\n",
+ TO_MHI_EXEC_STR(event));
+ switch (event) {
+ case MHI_EE_SBL:
+ st = DEV_ST_TRANSITION_SBL;
+ break;
+ case MHI_EE_WFW:
+ case MHI_EE_AMSS:
+ st = DEV_ST_TRANSITION_MISSION_MODE;
+ break;
+ case MHI_EE_RDDM:
+ mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ mhi_cntrl->ee = event;
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ wake_up_all(&mhi_cntrl->state_event);
+ break;
+ default:
+ dev_err(dev,
+ "Unhandled EE event: 0x%x\n", type);
+ }
+ if (st != DEV_ST_TRANSITION_MAX)
+ mhi_queue_state_transition(mhi_cntrl, st);
+
+ break;
+ }
+ case MHI_PKT_TYPE_TX_EVENT:
+ chan = MHI_TRE_GET_EV_CHID(local_rp);
+ mhi_chan = &mhi_cntrl->mhi_chan[chan];
+ parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
+ event_quota--;
+ break;
+ default:
+ dev_err(dev, "Unhandled event type: %d\n", type);
+ break;
+ }
+
+ mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
+ local_rp = ev_ring->rp;
+ dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+ count++;
+ }
+
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
+ mhi_ring_er_db(mhi_event);
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return count;
+}
+
+int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
+ struct mhi_event *mhi_event,
+ u32 event_quota)
+{
+ struct mhi_tre *dev_rp, *local_rp;
+ struct mhi_ring *ev_ring = &mhi_event->ring;
+ struct mhi_event_ctxt *er_ctxt =
+ &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_event->er_index];
+ int count = 0;
+ u32 chan;
+ struct mhi_chan *mhi_chan;
+
+ if (unlikely(MHI_EVENT_ACCESS_INVALID(mhi_cntrl->pm_state)))
+ return -EIO;
+
+ dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+ local_rp = ev_ring->rp;
+
+ while (dev_rp != local_rp && event_quota > 0) {
+ enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
+
+ chan = MHI_TRE_GET_EV_CHID(local_rp);
+ mhi_chan = &mhi_cntrl->mhi_chan[chan];
+
+ if (likely(type == MHI_PKT_TYPE_TX_EVENT)) {
+ parse_xfer_event(mhi_cntrl, local_rp, mhi_chan);
+ event_quota--;
+ } else if (type == MHI_PKT_TYPE_RSC_TX_EVENT) {
+ parse_rsc_event(mhi_cntrl, local_rp, mhi_chan);
+ event_quota--;
+ }
+
+ mhi_recycle_ev_ring_element(mhi_cntrl, ev_ring);
+ local_rp = ev_ring->rp;
+ dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+ count++;
+ }
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
+ mhi_ring_er_db(mhi_event);
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return count;
+}
+
+void mhi_ev_task(unsigned long data)
+{
+ struct mhi_event *mhi_event = (struct mhi_event *)data;
+ struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
+
+ /* process all pending events */
+ spin_lock_bh(&mhi_event->lock);
+ mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
+ spin_unlock_bh(&mhi_event->lock);
+}
+
+void mhi_ctrl_ev_task(unsigned long data)
+{
+ struct mhi_event *mhi_event = (struct mhi_event *)data;
+ struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ enum mhi_state state;
+ enum mhi_pm_state pm_state = 0;
+ int ret;
+
+ /*
+ * We can check PM state w/o a lock here because there is no way
+ * PM state can change from reg access valid to no access while this
+ * thread being executed.
+ */
+ if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
+ /*
+ * We may have a pending event but not allowed to
+ * process it since we are probably in a suspended state,
+ * so trigger a resume.
+ */
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+
+ return;
+ }
+
+ /* Process ctrl events events */
+ ret = mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
+
+ /*
+ * We received an IRQ but no events to process, maybe device went to
+ * SYS_ERR state? Check the state to confirm.
+ */
+ if (!ret) {
+ write_lock_irq(&mhi_cntrl->pm_lock);
+ state = mhi_get_mhi_state(mhi_cntrl);
+ if (state == MHI_STATE_SYS_ERR) {
+ dev_dbg(dev, "System error detected\n");
+ pm_state = mhi_tryset_pm_state(mhi_cntrl,
+ MHI_PM_SYS_ERR_DETECT);
+ }
+ write_unlock_irq(&mhi_cntrl->pm_lock);
+ if (pm_state == MHI_PM_SYS_ERR_DETECT)
+ schedule_work(&mhi_cntrl->syserr_worker);
+ }
+}
+
+static bool mhi_is_ring_full(struct mhi_controller *mhi_cntrl,
+ struct mhi_ring *ring)
+{
+ void *tmp = ring->wp + ring->el_size;
+
+ if (tmp >= (ring->base + ring->len))
+ tmp = ring->base;
+
+ return (tmp == ring->rp);
+}
+
+int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+ struct sk_buff *skb, size_t len, enum mhi_flags mflags)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
+ mhi_dev->dl_chan;
+ struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
+ struct mhi_ring *buf_ring = &mhi_chan->buf_ring;
+ struct mhi_buf_info *buf_info;
+ struct mhi_tre *mhi_tre;
+ int ret;
+
+ /* If MHI host pre-allocates buffers then client drivers cannot queue */
+ if (mhi_chan->pre_alloc)
+ return -EINVAL;
+
+ if (mhi_is_ring_full(mhi_cntrl, tre_ring))
+ return -ENOMEM;
+
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ return -EIO;
+ }
+
+ /* we're in M3 or transitioning to M3 */
+ if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+ }
+
+ /* Toggle wake to exit out of M2 */
+ mhi_cntrl->wake_toggle(mhi_cntrl);
+
+ /* Generate the TRE */
+ buf_info = buf_ring->wp;
+
+ buf_info->v_addr = skb->data;
+ buf_info->cb_buf = skb;
+ buf_info->wp = tre_ring->wp;
+ buf_info->dir = mhi_chan->dir;
+ buf_info->len = len;
+ ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
+ if (ret)
+ goto map_error;
+
+ mhi_tre = tre_ring->wp;
+
+ mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
+ mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_info->len);
+ mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(1, 1, 0, 0);
+
+ /* increment WP */
+ mhi_add_ring_element(mhi_cntrl, tre_ring);
+ mhi_add_ring_element(mhi_cntrl, buf_ring);
+
+ if (mhi_chan->dir == DMA_TO_DEVICE)
+ atomic_inc(&mhi_cntrl->pending_pkts);
+
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
+ read_lock_bh(&mhi_chan->lock);
+ mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+ read_unlock_bh(&mhi_chan->lock);
+ }
+
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return 0;
+
+map_error:
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_queue_skb);
+
+int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+ struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
+ mhi_dev->dl_chan;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ struct mhi_ring *tre_ring = &mhi_chan->tre_ring;
+ struct mhi_ring *buf_ring = &mhi_chan->buf_ring;
+ struct mhi_buf_info *buf_info;
+ struct mhi_tre *mhi_tre;
+
+ /* If MHI host pre-allocates buffers then client drivers cannot queue */
+ if (mhi_chan->pre_alloc)
+ return -EINVAL;
+
+ if (mhi_is_ring_full(mhi_cntrl, tre_ring))
+ return -ENOMEM;
+
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))) {
+ dev_err(dev, "MHI is not in activate state, PM state: %s\n",
+ to_mhi_pm_state_str(mhi_cntrl->pm_state));
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return -EIO;
+ }
+
+ /* we're in M3 or transitioning to M3 */
+ if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+ }
+
+ /* Toggle wake to exit out of M2 */
+ mhi_cntrl->wake_toggle(mhi_cntrl);
+
+ /* Generate the TRE */
+ buf_info = buf_ring->wp;
+ WARN_ON(buf_info->used);
+ buf_info->p_addr = mhi_buf->dma_addr;
+ buf_info->pre_mapped = true;
+ buf_info->cb_buf = mhi_buf;
+ buf_info->wp = tre_ring->wp;
+ buf_info->dir = mhi_chan->dir;
+ buf_info->len = len;
+
+ mhi_tre = tre_ring->wp;
+
+ mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
+ mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_info->len);
+ mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(1, 1, 0, 0);
+
+ /* increment WP */
+ mhi_add_ring_element(mhi_cntrl, tre_ring);
+ mhi_add_ring_element(mhi_cntrl, buf_ring);
+
+ if (mhi_chan->dir == DMA_TO_DEVICE)
+ atomic_inc(&mhi_cntrl->pending_pkts);
+
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
+ read_lock_bh(&mhi_chan->lock);
+ mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+ read_unlock_bh(&mhi_chan->lock);
+ }
+
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mhi_queue_dma);
+
+int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
+ void *buf, void *cb, size_t buf_len, enum mhi_flags flags)
+{
+ struct mhi_ring *buf_ring, *tre_ring;
+ struct mhi_tre *mhi_tre;
+ struct mhi_buf_info *buf_info;
+ int eot, eob, chain, bei;
+ int ret;
+
+ buf_ring = &mhi_chan->buf_ring;
+ tre_ring = &mhi_chan->tre_ring;
+
+ buf_info = buf_ring->wp;
+ buf_info->v_addr = buf;
+ buf_info->cb_buf = cb;
+ buf_info->wp = tre_ring->wp;
+ buf_info->dir = mhi_chan->dir;
+ buf_info->len = buf_len;
+
+ ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
+ if (ret)
+ return ret;
+
+ eob = !!(flags & MHI_EOB);
+ eot = !!(flags & MHI_EOT);
+ chain = !!(flags & MHI_CHAIN);
+ bei = !!(mhi_chan->intmod);
+
+ mhi_tre = tre_ring->wp;
+ mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
+ mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(buf_len);
+ mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);
+
+ /* increment WP */
+ mhi_add_ring_element(mhi_cntrl, tre_ring);
+ mhi_add_ring_element(mhi_cntrl, buf_ring);
+
+ return 0;
+}
+
+int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+ void *buf, size_t len, enum mhi_flags mflags)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? mhi_dev->ul_chan :
+ mhi_dev->dl_chan;
+ struct mhi_ring *tre_ring;
+ unsigned long flags;
+ int ret;
+
+ /*
+ * this check here only as a guard, it's always
+ * possible mhi can enter error while executing rest of function,
+ * which is not fatal so we do not need to hold pm_lock
+ */
+ if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
+ return -EIO;
+
+ tre_ring = &mhi_chan->tre_ring;
+ if (mhi_is_ring_full(mhi_cntrl, tre_ring))
+ return -ENOMEM;
+
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf, buf, len, mflags);
+ if (unlikely(ret))
+ return ret;
+
+ read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
+
+ /* we're in M3 or transitioning to M3 */
+ if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+ }
+
+ /* Toggle wake to exit out of M2 */
+ mhi_cntrl->wake_toggle(mhi_cntrl);
+
+ if (mhi_chan->dir == DMA_TO_DEVICE)
+ atomic_inc(&mhi_cntrl->pending_pkts);
+
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) {
+ unsigned long flags;
+
+ read_lock_irqsave(&mhi_chan->lock, flags);
+ mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+ read_unlock_irqrestore(&mhi_chan->lock, flags);
+ }
+
+ read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mhi_queue_buf);
+
+int mhi_send_cmd(struct mhi_controller *mhi_cntrl,
+ struct mhi_chan *mhi_chan,
+ enum mhi_cmd_type cmd)
+{
+ struct mhi_tre *cmd_tre = NULL;
+ struct mhi_cmd *mhi_cmd = &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING];
+ struct mhi_ring *ring = &mhi_cmd->ring;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ int chan = 0;
+
+ if (mhi_chan)
+ chan = mhi_chan->chan;
+
+ spin_lock_bh(&mhi_cmd->lock);
+ if (!get_nr_avail_ring_elements(mhi_cntrl, ring)) {
+ spin_unlock_bh(&mhi_cmd->lock);
+ return -ENOMEM;
+ }
+
+ /* prepare the cmd tre */
+ cmd_tre = ring->wp;
+ switch (cmd) {
+ case MHI_CMD_RESET_CHAN:
+ cmd_tre->ptr = MHI_TRE_CMD_RESET_PTR;
+ cmd_tre->dword[0] = MHI_TRE_CMD_RESET_DWORD0;
+ cmd_tre->dword[1] = MHI_TRE_CMD_RESET_DWORD1(chan);
+ break;
+ case MHI_CMD_START_CHAN:
+ cmd_tre->ptr = MHI_TRE_CMD_START_PTR;
+ cmd_tre->dword[0] = MHI_TRE_CMD_START_DWORD0;
+ cmd_tre->dword[1] = MHI_TRE_CMD_START_DWORD1(chan);
+ break;
+ default:
+ dev_err(dev, "Command not supported\n");
+ break;
+ }
+
+ /* queue to hardware */
+ mhi_add_ring_element(mhi_cntrl, ring);
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
+ mhi_ring_cmd_db(mhi_cntrl, mhi_cmd);
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ spin_unlock_bh(&mhi_cmd->lock);
+
+ return 0;
+}
+
+static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
+ struct mhi_chan *mhi_chan)
+{
+ int ret;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+
+ dev_dbg(dev, "Entered: unprepare channel:%d\n", mhi_chan->chan);
+
+ /* no more processing events for this channel */
+ mutex_lock(&mhi_chan->mutex);
+ write_lock_irq(&mhi_chan->lock);
+ if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED) {
+ write_unlock_irq(&mhi_chan->lock);
+ mutex_unlock(&mhi_chan->mutex);
+ return;
+ }
+
+ mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
+ write_unlock_irq(&mhi_chan->lock);
+
+ reinit_completion(&mhi_chan->completion);
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ goto error_invalid_state;
+ }
+
+ mhi_cntrl->wake_toggle(mhi_cntrl);
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+ ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_RESET_CHAN);
+ if (ret)
+ goto error_invalid_state;
+
+ /* even if it fails we will still reset */
+ ret = wait_for_completion_timeout(&mhi_chan->completion,
+ msecs_to_jiffies(mhi_cntrl->timeout_ms));
+ if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS)
+ dev_err(dev,
+ "Failed to receive cmd completion, still resetting\n");
+
+error_invalid_state:
+ if (!mhi_chan->offload_ch) {
+ mhi_reset_chan(mhi_cntrl, mhi_chan);
+ mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
+ }
+ dev_dbg(dev, "chan:%d successfully resetted\n", mhi_chan->chan);
+ mutex_unlock(&mhi_chan->mutex);
+}
+
+int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
+ struct mhi_chan *mhi_chan)
+{
+ int ret = 0;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+
+ dev_dbg(dev, "Preparing channel: %d\n", mhi_chan->chan);
+
+ if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
+ dev_err(dev,
+ "Current EE: %s Required EE Mask: 0x%x for chan: %s\n",
+ TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask,
+ mhi_chan->name);
+ return -ENOTCONN;
+ }
+
+ mutex_lock(&mhi_chan->mutex);
+
+ /* If channel is not in disable state, do not allow it to start */
+ if (mhi_chan->ch_state != MHI_CH_STATE_DISABLED) {
+ ret = -EIO;
+ dev_dbg(dev, "channel: %d is not in disabled state\n",
+ mhi_chan->chan);
+ goto error_init_chan;
+ }
+
+ /* Check of client manages channel context for offload channels */
+ if (!mhi_chan->offload_ch) {
+ ret = mhi_init_chan_ctxt(mhi_cntrl, mhi_chan);
+ if (ret)
+ goto error_init_chan;
+ }
+
+ reinit_completion(&mhi_chan->completion);
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ ret = -EIO;
+ goto error_pm_state;
+ }
+
+ mhi_cntrl->wake_toggle(mhi_cntrl);
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ mhi_cntrl->runtime_get(mhi_cntrl);
+ mhi_cntrl->runtime_put(mhi_cntrl);
+
+ ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_START_CHAN);
+ if (ret)
+ goto error_pm_state;
+
+ ret = wait_for_completion_timeout(&mhi_chan->completion,
+ msecs_to_jiffies(mhi_cntrl->timeout_ms));
+ if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) {
+ ret = -EIO;
+ goto error_pm_state;
+ }
+
+ write_lock_irq(&mhi_chan->lock);
+ mhi_chan->ch_state = MHI_CH_STATE_ENABLED;
+ write_unlock_irq(&mhi_chan->lock);
+
+ /* Pre-allocate buffer for xfer ring */
+ if (mhi_chan->pre_alloc) {
+ int nr_el = get_nr_avail_ring_elements(mhi_cntrl,
+ &mhi_chan->tre_ring);
+ size_t len = mhi_cntrl->buffer_len;
+
+ while (nr_el--) {
+ void *buf;
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto error_pre_alloc;
+ }
+
+ /* Prepare transfer descriptors */
+ ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf, buf,
+ len, MHI_EOT);
+ if (ret) {
+ kfree(buf);
+ goto error_pre_alloc;
+ }
+ }
+
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ if (MHI_DB_ACCESS_VALID(mhi_cntrl)) {
+ read_lock_irq(&mhi_chan->lock);
+ mhi_ring_chan_db(mhi_cntrl, mhi_chan);
+ read_unlock_irq(&mhi_chan->lock);
+ }
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+ }
+
+ mutex_unlock(&mhi_chan->mutex);
+
+ dev_dbg(dev, "Chan: %d successfully moved to start state\n",
+ mhi_chan->chan);
+
+ return 0;
+
+error_pm_state:
+ if (!mhi_chan->offload_ch)
+ mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
+
+error_init_chan:
+ mutex_unlock(&mhi_chan->mutex);
+
+ return ret;
+
+error_pre_alloc:
+ mutex_unlock(&mhi_chan->mutex);
+ __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
+
+ return ret;
+}
+
+static void mhi_mark_stale_events(struct mhi_controller *mhi_cntrl,
+ struct mhi_event *mhi_event,
+ struct mhi_event_ctxt *er_ctxt,
+ int chan)
+
+{
+ struct mhi_tre *dev_rp, *local_rp;
+ struct mhi_ring *ev_ring;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
+ unsigned long flags;
+
+ dev_dbg(dev, "Marking all events for chan: %d as stale\n", chan);
+
+ ev_ring = &mhi_event->ring;
+
+ /* mark all stale events related to channel as STALE event */
+ spin_lock_irqsave(&mhi_event->lock, flags);
+ dev_rp = mhi_to_virtual(ev_ring, er_ctxt->rp);
+
+ local_rp = ev_ring->rp;
+ while (dev_rp != local_rp) {
+ if (MHI_TRE_GET_EV_TYPE(local_rp) == MHI_PKT_TYPE_TX_EVENT &&
+ chan == MHI_TRE_GET_EV_CHID(local_rp))
+ local_rp->dword[1] = MHI_TRE_EV_DWORD1(chan,
+ MHI_PKT_TYPE_STALE_EVENT);
+ local_rp++;
+ if (local_rp == (ev_ring->base + ev_ring->len))
+ local_rp = ev_ring->base;
+ }
+
+ dev_dbg(dev, "Finished marking events as stale events\n");
+ spin_unlock_irqrestore(&mhi_event->lock, flags);
+}
+
+static void mhi_reset_data_chan(struct mhi_controller *mhi_cntrl,
+ struct mhi_chan *mhi_chan)
+{
+ struct mhi_ring *buf_ring, *tre_ring;
+ struct mhi_result result;
+
+ /* Reset any pending buffers */
+ buf_ring = &mhi_chan->buf_ring;
+ tre_ring = &mhi_chan->tre_ring;
+ result.transaction_status = -ENOTCONN;
+ result.bytes_xferd = 0;
+ while (tre_ring->rp != tre_ring->wp) {
+ struct mhi_buf_info *buf_info = buf_ring->rp;
+
+ if (mhi_chan->dir == DMA_TO_DEVICE)
+ atomic_dec(&mhi_cntrl->pending_pkts);
+
+ if (!buf_info->pre_mapped)
+ mhi_cntrl->unmap_single(mhi_cntrl, buf_info);
+
+ mhi_del_ring_element(mhi_cntrl, buf_ring);
+ mhi_del_ring_element(mhi_cntrl, tre_ring);
+
+ if (mhi_chan->pre_alloc) {
+ kfree(buf_info->cb_buf);
+ } else {
+ result.buf_addr = buf_info->cb_buf;
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+ }
+ }
+}
+
+void mhi_reset_chan(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan)
+{
+ struct mhi_event *mhi_event;
+ struct mhi_event_ctxt *er_ctxt;
+ int chan = mhi_chan->chan;
+
+ /* Nothing to reset, client doesn't queue buffers */
+ if (mhi_chan->offload_ch)
+ return;
+
+ read_lock_bh(&mhi_cntrl->pm_lock);
+ mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
+ er_ctxt = &mhi_cntrl->mhi_ctxt->er_ctxt[mhi_chan->er_index];
+
+ mhi_mark_stale_events(mhi_cntrl, mhi_event, er_ctxt, chan);
+
+ mhi_reset_data_chan(mhi_cntrl, mhi_chan);
+
+ read_unlock_bh(&mhi_cntrl->pm_lock);
+}
+
+/* Move channel to start state */
+int mhi_prepare_for_transfer(struct mhi_device *mhi_dev)
+{
+ int ret, dir;
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan;
+
+ for (dir = 0; dir < 2; dir++) {
+ mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
+ if (!mhi_chan)
+ continue;
+
+ ret = mhi_prepare_channel(mhi_cntrl, mhi_chan);
+ if (ret)
+ goto error_open_chan;
+ }
+
+ return 0;
+
+error_open_chan:
+ for (--dir; dir >= 0; dir--) {
+ mhi_chan = dir ? mhi_dev->dl_chan : mhi_dev->ul_chan;
+ if (!mhi_chan)
+ continue;
+
+ __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_prepare_for_transfer);
+
+void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan;
+ int dir;
+
+ for (dir = 0; dir < 2; dir++) {
+ mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
+ if (!mhi_chan)
+ continue;
+
+ __mhi_unprepare_channel(mhi_cntrl, mhi_chan);
+ }
+}
+EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer);
+
+int mhi_poll(struct mhi_device *mhi_dev, u32 budget)
+{
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct mhi_chan *mhi_chan = mhi_dev->dl_chan;
+ struct mhi_event *mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
+ int ret;
+
+ spin_lock_bh(&mhi_event->lock);
+ ret = mhi_event->process_event(mhi_cntrl, mhi_event, budget);
+ spin_unlock_bh(&mhi_event->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mhi_poll);