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bus: mhi: core: Add support for data transfer
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Add support for transferring data between external modem and host
processor using MHI protocol.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/988

Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[mani: splitted the data transfer patch and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Link: https://lore.kernel.org/r/20200220095854.4804-12-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Manivannan Sadhasivam authored and Greg Kroah-Hartman committed Mar 19, 2020
1 parent 1d3173a commit 189ff97
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Showing 5 changed files with 979 additions and 8 deletions.
130 changes: 124 additions & 6 deletions drivers/bus/mhi/core/init.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -491,6 +491,73 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
return 0;
}

void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *buf_ring;
struct mhi_ring *tre_ring;
struct mhi_chan_ctxt *chan_ctxt;

buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];

mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
tre_ring->pre_aligned, tre_ring->dma_handle);
vfree(buf_ring->base);

buf_ring->base = tre_ring->base = NULL;
chan_ctxt->rbase = 0;
}

int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan)
{
struct mhi_ring *buf_ring;
struct mhi_ring *tre_ring;
struct mhi_chan_ctxt *chan_ctxt;
u32 tmp;
int ret;

buf_ring = &mhi_chan->buf_ring;
tre_ring = &mhi_chan->tre_ring;
tre_ring->el_size = sizeof(struct mhi_tre);
tre_ring->len = tre_ring->el_size * tre_ring->elements;
chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
if (ret)
return -ENOMEM;

buf_ring->el_size = sizeof(struct mhi_buf_info);
buf_ring->len = buf_ring->el_size * buf_ring->elements;
buf_ring->base = vzalloc(buf_ring->len);

if (!buf_ring->base) {
mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
tre_ring->pre_aligned, tre_ring->dma_handle);
return -ENOMEM;
}

tmp = chan_ctxt->chcfg;
tmp &= ~CHAN_CTX_CHSTATE_MASK;
tmp |= (MHI_CH_STATE_ENABLED << CHAN_CTX_CHSTATE_SHIFT);
chan_ctxt->chcfg = tmp;

chan_ctxt->rbase = tre_ring->iommu_base;
chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
chan_ctxt->rlen = tre_ring->len;
tre_ring->ctxt_wp = &chan_ctxt->wp;

tre_ring->rp = tre_ring->wp = tre_ring->base;
buf_ring->rp = buf_ring->wp = buf_ring->base;
mhi_chan->db_cfg.db_mode = 1;

/* Update to all cores */
smp_wmb();

return 0;
}

static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
struct mhi_controller_config *config)
{
Expand Down Expand Up @@ -799,6 +866,14 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
rwlock_init(&mhi_chan->lock);
}

if (mhi_cntrl->bounce_buf) {
mhi_cntrl->map_single = mhi_map_single_use_bb;
mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
} else {
mhi_cntrl->map_single = mhi_map_single_no_bb;
mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
}

/* Register controller with MHI bus */
mhi_dev = mhi_alloc_device(mhi_cntrl);
if (IS_ERR(mhi_dev)) {
Expand Down Expand Up @@ -969,20 +1044,33 @@ static int mhi_driver_probe(struct device *dev)
struct mhi_event *mhi_event;
struct mhi_chan *ul_chan = mhi_dev->ul_chan;
struct mhi_chan *dl_chan = mhi_dev->dl_chan;
int ret;

/* Bring device out of LPM */
ret = mhi_device_get_sync(mhi_dev);
if (ret)
return ret;

ret = -EINVAL;

if (ul_chan) {
/*
* If channel supports LPM notifications then status_cb should
* be provided
*/
if (ul_chan->lpm_notify && !mhi_drv->status_cb)
return -EINVAL;
goto exit_probe;

/* For non-offload channels then xfer_cb should be provided */
if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
return -EINVAL;
goto exit_probe;

ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
if (ul_chan->auto_start) {
ret = mhi_prepare_channel(mhi_cntrl, ul_chan);
if (ret)
goto exit_probe;
}
}

if (dl_chan) {
Expand All @@ -991,11 +1079,11 @@ static int mhi_driver_probe(struct device *dev)
* be provided
*/
if (dl_chan->lpm_notify && !mhi_drv->status_cb)
return -EINVAL;
goto exit_probe;

/* For non-offload channels then xfer_cb should be provided */
if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
return -EINVAL;
goto exit_probe;

mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];

Expand All @@ -1005,19 +1093,36 @@ static int mhi_driver_probe(struct device *dev)
* notify pending data
*/
if (mhi_event->cl_manage && !mhi_drv->status_cb)
return -EINVAL;
goto exit_probe;

dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
}

/* Call the user provided probe function */
return mhi_drv->probe(mhi_dev, mhi_dev->id);
ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
if (ret)
goto exit_probe;

if (dl_chan && dl_chan->auto_start)
mhi_prepare_channel(mhi_cntrl, dl_chan);

mhi_device_put(mhi_dev);

return ret;

exit_probe:
mhi_unprepare_from_transfer(mhi_dev);

mhi_device_put(mhi_dev);

return ret;
}

static int mhi_driver_remove(struct device *dev)
{
struct mhi_device *mhi_dev = to_mhi_device(dev);
struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
struct mhi_chan *mhi_chan;
enum mhi_ch_state ch_state[] = {
MHI_CH_STATE_DISABLED,
Expand Down Expand Up @@ -1049,6 +1154,10 @@ static int mhi_driver_remove(struct device *dev)
mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
write_unlock_irq(&mhi_chan->lock);

/* Reset the non-offload channel */
if (!mhi_chan->offload_ch)
mhi_reset_chan(mhi_cntrl, mhi_chan);

mutex_unlock(&mhi_chan->mutex);
}

Expand All @@ -1063,11 +1172,20 @@ static int mhi_driver_remove(struct device *dev)

mutex_lock(&mhi_chan->mutex);

if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
!mhi_chan->offload_ch)
mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);

mhi_chan->ch_state = MHI_CH_STATE_DISABLED;

mutex_unlock(&mhi_chan->mutex);
}

read_lock_bh(&mhi_cntrl->pm_lock);
while (mhi_dev->dev_wake)
mhi_device_put(mhi_dev);
read_unlock_bh(&mhi_cntrl->pm_lock);

return 0;
}

Expand Down
22 changes: 22 additions & 0 deletions drivers/bus/mhi/core/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -587,6 +587,8 @@ int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl);
void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl);
int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl);
int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl);
int mhi_send_cmd(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
enum mhi_cmd_type cmd);

/* Register access methods */
void mhi_db_brstmode(struct mhi_controller *mhi_cntrl, struct db_cfg *db_cfg,
Expand Down Expand Up @@ -618,6 +620,14 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl);
void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl);
void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
struct image_info *img_info);
int mhi_prepare_channel(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan);
int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan);
void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan);
void mhi_reset_chan(struct mhi_controller *mhi_cntrl,
struct mhi_chan *mhi_chan);

/* Memory allocation methods */
static inline void *mhi_alloc_coherent(struct mhi_controller *mhi_cntrl,
Expand Down Expand Up @@ -652,4 +662,16 @@ irqreturn_t mhi_irq_handler(int irq_number, void *dev);
irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *dev);
irqreturn_t mhi_intvec_handler(int irq_number, void *dev);

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);

int mhi_map_single_no_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info);
int mhi_map_single_use_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info);
void mhi_unmap_single_no_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info);
void mhi_unmap_single_use_bb(struct mhi_controller *mhi_cntrl,
struct mhi_buf_info *buf_info);

#endif /* _MHI_INT_H */
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