diff options
Diffstat (limited to 'drivers/bus/mhi/ep/main.c')
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 1591 |
1 files changed, 1591 insertions, 0 deletions
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c new file mode 100644 index 000000000000..40109a79017a --- /dev/null +++ b/drivers/bus/mhi/ep/main.c @@ -0,0 +1,1591 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MHI Endpoint bus stack + * + * Copyright (C) 2022 Linaro Ltd. + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + */ + +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/dma-direction.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/mhi_ep.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include "internal.h" + +#define M0_WAIT_DELAY_MS 100 +#define M0_WAIT_COUNT 100 + +static DEFINE_IDA(mhi_ep_cntrl_ida); + +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id); +static int mhi_ep_destroy_device(struct device *dev, void *data); + +static int mhi_ep_send_event(struct mhi_ep_cntrl *mhi_cntrl, u32 ring_idx, + struct mhi_ring_element *el, bool bei) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + union mhi_ep_ring_ctx *ctx; + struct mhi_ep_ring *ring; + int ret; + + mutex_lock(&mhi_cntrl->event_lock); + ring = &mhi_cntrl->mhi_event[ring_idx].ring; + ctx = (union mhi_ep_ring_ctx *)&mhi_cntrl->ev_ctx_cache[ring_idx]; + if (!ring->started) { + ret = mhi_ep_ring_start(mhi_cntrl, ring, ctx); + if (ret) { + dev_err(dev, "Error starting event ring (%u)\n", ring_idx); + goto err_unlock; + } + } + + /* Add element to the event ring */ + ret = mhi_ep_ring_add_element(ring, el); + if (ret) { + dev_err(dev, "Error adding element to event ring (%u)\n", ring_idx); + goto err_unlock; + } + + mutex_unlock(&mhi_cntrl->event_lock); + + /* + * Raise IRQ to host only if the BEI flag is not set in TRE. Host might + * set this flag for interrupt moderation as per MHI protocol. + */ + if (!bei) + mhi_cntrl->raise_irq(mhi_cntrl, ring->irq_vector); + + return 0; + +err_unlock: + mutex_unlock(&mhi_cntrl->event_lock); + + return ret; +} + +static int mhi_ep_send_completion_event(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_ring *ring, + struct mhi_ring_element *tre, u32 len, enum mhi_ev_ccs code) +{ + struct mhi_ring_element event = {}; + + event.ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(*tre)); + event.dword[0] = MHI_TRE_EV_DWORD0(code, len); + event.dword[1] = MHI_TRE_EV_DWORD1(ring->ch_id, MHI_PKT_TYPE_TX_EVENT); + + return mhi_ep_send_event(mhi_cntrl, ring->er_index, &event, MHI_TRE_DATA_GET_BEI(tre)); +} + +int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state state) +{ + struct mhi_ring_element event = {}; + + event.dword[0] = MHI_SC_EV_DWORD0(state); + event.dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_STATE_CHANGE_EVENT); + + return mhi_ep_send_event(mhi_cntrl, 0, &event, 0); +} + +int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_env) +{ + struct mhi_ring_element event = {}; + + event.dword[0] = MHI_EE_EV_DWORD0(exec_env); + event.dword[1] = MHI_SC_EV_DWORD1(MHI_PKT_TYPE_EE_EVENT); + + return mhi_ep_send_event(mhi_cntrl, 0, &event, 0); +} + +static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ev_ccs code) +{ + struct mhi_ep_ring *ring = &mhi_cntrl->mhi_cmd->ring; + struct mhi_ring_element event = {}; + + event.ptr = cpu_to_le64(ring->rbase + ring->rd_offset * sizeof(struct mhi_ring_element)); + event.dword[0] = MHI_CC_EV_DWORD0(code); + event.dword[1] = MHI_CC_EV_DWORD1(MHI_PKT_TYPE_CMD_COMPLETION_EVENT); + + return mhi_ep_send_event(mhi_cntrl, 0, &event, 0); +} + +static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_element *el) +{ + struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_result result = {}; + struct mhi_ep_chan *mhi_chan; + struct mhi_ep_ring *ch_ring; + u32 tmp, ch_id; + int ret; + + ch_id = MHI_TRE_GET_CMD_CHID(el); + mhi_chan = &mhi_cntrl->mhi_chan[ch_id]; + ch_ring = &mhi_cntrl->mhi_chan[ch_id].ring; + + switch (MHI_TRE_GET_CMD_TYPE(el)) { + case MHI_PKT_TYPE_START_CHAN_CMD: + dev_dbg(dev, "Received START command for channel (%u)\n", ch_id); + + mutex_lock(&mhi_chan->lock); + /* Initialize and configure the corresponding channel ring */ + if (!ch_ring->started) { + ret = mhi_ep_ring_start(mhi_cntrl, ch_ring, + (union mhi_ep_ring_ctx *)&mhi_cntrl->ch_ctx_cache[ch_id]); + if (ret) { + dev_err(dev, "Failed to start ring for channel (%u)\n", ch_id); + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, + MHI_EV_CC_UNDEFINED_ERR); + if (ret) + dev_err(dev, "Error sending completion event: %d\n", ret); + + goto err_unlock; + } + } + + /* Set channel state to RUNNING */ + mhi_chan->state = MHI_CH_STATE_RUNNING; + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg); + tmp &= ~CHAN_CTX_CHSTATE_MASK; + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING); + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp); + + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS); + if (ret) { + dev_err(dev, "Error sending command completion event (%u)\n", + MHI_EV_CC_SUCCESS); + goto err_unlock; + } + + mutex_unlock(&mhi_chan->lock); + + /* + * Create MHI device only during UL channel start. Since the MHI + * channels operate in a pair, we'll associate both UL and DL + * channels to the same device. + * + * We also need to check for mhi_dev != NULL because, the host + * will issue START_CHAN command during resume and we don't + * destroy the device during suspend. + */ + if (!(ch_id % 2) && !mhi_chan->mhi_dev) { + ret = mhi_ep_create_device(mhi_cntrl, ch_id); + if (ret) { + dev_err(dev, "Error creating device for channel (%u)\n", ch_id); + mhi_ep_handle_syserr(mhi_cntrl); + return ret; + } + } + + /* Finally, enable DB for the channel */ + mhi_ep_mmio_enable_chdb(mhi_cntrl, ch_id); + + break; + case MHI_PKT_TYPE_STOP_CHAN_CMD: + dev_dbg(dev, "Received STOP command for channel (%u)\n", ch_id); + if (!ch_ring->started) { + dev_err(dev, "Channel (%u) not opened\n", ch_id); + return -ENODEV; + } + + mutex_lock(&mhi_chan->lock); + /* Disable DB for the channel */ + mhi_ep_mmio_disable_chdb(mhi_cntrl, ch_id); + + /* Send channel disconnect status to client drivers */ + result.transaction_status = -ENOTCONN; + result.bytes_xferd = 0; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + + /* Set channel state to STOP */ + mhi_chan->state = MHI_CH_STATE_STOP; + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg); + tmp &= ~CHAN_CTX_CHSTATE_MASK; + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_STOP); + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp); + + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS); + if (ret) { + dev_err(dev, "Error sending command completion event (%u)\n", + MHI_EV_CC_SUCCESS); + goto err_unlock; + } + + mutex_unlock(&mhi_chan->lock); + break; + case MHI_PKT_TYPE_RESET_CHAN_CMD: + dev_dbg(dev, "Received STOP command for channel (%u)\n", ch_id); + if (!ch_ring->started) { + dev_err(dev, "Channel (%u) not opened\n", ch_id); + return -ENODEV; + } + + mutex_lock(&mhi_chan->lock); + /* Stop and reset the transfer ring */ + mhi_ep_ring_reset(mhi_cntrl, ch_ring); + + /* Send channel disconnect status to client driver */ + result.transaction_status = -ENOTCONN; + result.bytes_xferd = 0; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + + /* Set channel state to DISABLED */ + mhi_chan->state = MHI_CH_STATE_DISABLED; + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[ch_id].chcfg); + tmp &= ~CHAN_CTX_CHSTATE_MASK; + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_DISABLED); + mhi_cntrl->ch_ctx_cache[ch_id].chcfg = cpu_to_le32(tmp); + + ret = mhi_ep_send_cmd_comp_event(mhi_cntrl, MHI_EV_CC_SUCCESS); + if (ret) { + dev_err(dev, "Error sending command completion event (%u)\n", + MHI_EV_CC_SUCCESS); + goto err_unlock; + } + + mutex_unlock(&mhi_chan->lock); + break; + default: + dev_err(dev, "Invalid command received: %lu for channel (%u)\n", + MHI_TRE_GET_CMD_TYPE(el), ch_id); + return -EINVAL; + } + + return 0; + +err_unlock: + mutex_unlock(&mhi_chan->lock); + + return ret; +} + +bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir) +{ + struct mhi_ep_chan *mhi_chan = (dir == DMA_FROM_DEVICE) ? mhi_dev->dl_chan : + mhi_dev->ul_chan; + struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl; + struct mhi_ep_ring *ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring; + + return !!(ring->rd_offset == ring->wr_offset); +} +EXPORT_SYMBOL_GPL(mhi_ep_queue_is_empty); + +static int mhi_ep_read_channel(struct mhi_ep_cntrl *mhi_cntrl, + struct mhi_ep_ring *ring, + struct mhi_result *result, + u32 len) +{ + struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ring->ch_id]; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + size_t tr_len, read_offset, write_offset; + struct mhi_ring_element *el; + bool tr_done = false; + void *write_addr; + u64 read_addr; + u32 buf_left; + int ret; + + buf_left = len; + + do { + /* Don't process the transfer ring if the channel is not in RUNNING state */ + if (mhi_chan->state != MHI_CH_STATE_RUNNING) { + dev_err(dev, "Channel not available\n"); + return -ENODEV; + } + + el = &ring->ring_cache[ring->rd_offset]; + + /* Check if there is data pending to be read from previous read operation */ + if (mhi_chan->tre_bytes_left) { + dev_dbg(dev, "TRE bytes remaining: %u\n", mhi_chan->tre_bytes_left); + tr_len = min(buf_left, mhi_chan->tre_bytes_left); + } else { + mhi_chan->tre_loc = MHI_TRE_DATA_GET_PTR(el); + mhi_chan->tre_size = MHI_TRE_DATA_GET_LEN(el); + mhi_chan->tre_bytes_left = mhi_chan->tre_size; + + tr_len = min(buf_left, mhi_chan->tre_size); + } + + read_offset = mhi_chan->tre_size - mhi_chan->tre_bytes_left; + write_offset = len - buf_left; + read_addr = mhi_chan->tre_loc + read_offset; + write_addr = result->buf_addr + write_offset; + + dev_dbg(dev, "Reading %zd bytes from channel (%u)\n", tr_len, ring->ch_id); + ret = mhi_cntrl->read_from_host(mhi_cntrl, read_addr, write_addr, tr_len); + if (ret < 0) { + dev_err(&mhi_chan->mhi_dev->dev, "Error reading from channel\n"); + return ret; + } + + buf_left -= tr_len; + mhi_chan->tre_bytes_left -= tr_len; + + /* + * Once the TRE (Transfer Ring Element) of a TD (Transfer Descriptor) has been + * read completely: + * + * 1. Send completion event to the host based on the flags set in TRE. + * 2. Increment the local read offset of the transfer ring. + */ + if (!mhi_chan->tre_bytes_left) { + /* + * The host will split the data packet into multiple TREs if it can't fit + * the packet in a single TRE. In that case, CHAIN flag will be set by the + * host for all TREs except the last one. + */ + if (MHI_TRE_DATA_GET_CHAIN(el)) { + /* + * IEOB (Interrupt on End of Block) flag will be set by the host if + * it expects the completion event for all TREs of a TD. + */ + if (MHI_TRE_DATA_GET_IEOB(el)) { + ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, + MHI_TRE_DATA_GET_LEN(el), + MHI_EV_CC_EOB); + if (ret < 0) { + dev_err(&mhi_chan->mhi_dev->dev, + "Error sending transfer compl. event\n"); + return ret; + } + } + } else { + /* + * IEOT (Interrupt on End of Transfer) flag will be set by the host + * for the last TRE of the TD and expects the completion event for + * the same. + */ + if (MHI_TRE_DATA_GET_IEOT(el)) { + ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, + MHI_TRE_DATA_GET_LEN(el), + MHI_EV_CC_EOT); + if (ret < 0) { + dev_err(&mhi_chan->mhi_dev->dev, + "Error sending transfer compl. event\n"); + return ret; + } + } + + tr_done = true; + } + + mhi_ep_ring_inc_index(ring); + } + + result->bytes_xferd += tr_len; + } while (buf_left && !tr_done); + + return 0; +} + +static int mhi_ep_process_ch_ring(struct mhi_ep_ring *ring, struct mhi_ring_element *el) +{ + struct mhi_ep_cntrl *mhi_cntrl = ring->mhi_cntrl; + struct mhi_result result = {}; + u32 len = MHI_EP_DEFAULT_MTU; + struct mhi_ep_chan *mhi_chan; + int ret; + + mhi_chan = &mhi_cntrl->mhi_chan[ring->ch_id]; + + /* + * Bail out if transfer callback is not registered for the channel. + * This is most likely due to the client driver not loaded at this point. + */ + if (!mhi_chan->xfer_cb) { + dev_err(&mhi_chan->mhi_dev->dev, "Client driver not available\n"); + return -ENODEV; + } + + if (ring->ch_id % 2) { + /* DL channel */ + result.dir = mhi_chan->dir; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + } else { + /* UL channel */ + result.buf_addr = kzalloc(len, GFP_KERNEL); + if (!result.buf_addr) + return -ENOMEM; + + do { + ret = mhi_ep_read_channel(mhi_cntrl, ring, &result, len); + if (ret < 0) { + dev_err(&mhi_chan->mhi_dev->dev, "Failed to read channel\n"); + kfree(result.buf_addr); + return ret; + } + + result.dir = mhi_chan->dir; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + result.bytes_xferd = 0; + memset(result.buf_addr, 0, len); + + /* Read until the ring becomes empty */ + } while (!mhi_ep_queue_is_empty(mhi_chan->mhi_dev, DMA_TO_DEVICE)); + + kfree(result.buf_addr); + } + + return 0; +} + +/* TODO: Handle partially formed TDs */ +int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb) +{ + struct mhi_ep_cntrl *mhi_cntrl = mhi_dev->mhi_cntrl; + struct mhi_ep_chan *mhi_chan = mhi_dev->dl_chan; + struct device *dev = &mhi_chan->mhi_dev->dev; + struct mhi_ring_element *el; + u32 buf_left, read_offset; + struct mhi_ep_ring *ring; + enum mhi_ev_ccs code; + void *read_addr; + u64 write_addr; + size_t tr_len; + u32 tre_len; + int ret; + + buf_left = skb->len; + ring = &mhi_cntrl->mhi_chan[mhi_chan->chan].ring; + + mutex_lock(&mhi_chan->lock); + + do { + /* Don't process the transfer ring if the channel is not in RUNNING state */ + if (mhi_chan->state != MHI_CH_STATE_RUNNING) { + dev_err(dev, "Channel not available\n"); + ret = -ENODEV; + goto err_exit; + } + + if (mhi_ep_queue_is_empty(mhi_dev, DMA_FROM_DEVICE)) { + dev_err(dev, "TRE not available!\n"); + ret = -ENOSPC; + goto err_exit; + } + + el = &ring->ring_cache[ring->rd_offset]; + tre_len = MHI_TRE_DATA_GET_LEN(el); + + tr_len = min(buf_left, tre_len); + read_offset = skb->len - buf_left; + read_addr = skb->data + read_offset; + write_addr = MHI_TRE_DATA_GET_PTR(el); + + dev_dbg(dev, "Writing %zd bytes to channel (%u)\n", tr_len, ring->ch_id); + ret = mhi_cntrl->write_to_host(mhi_cntrl, read_addr, write_addr, tr_len); + if (ret < 0) { + dev_err(dev, "Error writing to the channel\n"); + goto err_exit; + } + + buf_left -= tr_len; + /* + * For all TREs queued by the host for DL channel, only the EOT flag will be set. + * If the packet doesn't fit into a single TRE, send the OVERFLOW event to + * the host so that the host can adjust the packet boundary to next TREs. Else send + * the EOT event to the host indicating the packet boundary. + */ + if (buf_left) + code = MHI_EV_CC_OVERFLOW; + else + code = MHI_EV_CC_EOT; + + ret = mhi_ep_send_completion_event(mhi_cntrl, ring, el, tr_len, code); + if (ret) { + dev_err(dev, "Error sending transfer completion event\n"); + goto err_exit; + } + + mhi_ep_ring_inc_index(ring); + } while (buf_left); + + mutex_unlock(&mhi_chan->lock); + + return 0; + +err_exit: + mutex_unlock(&mhi_chan->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_ep_queue_skb); + +static int mhi_ep_cache_host_cfg(struct mhi_ep_cntrl *mhi_cntrl) +{ + size_t cmd_ctx_host_size, ch_ctx_host_size, ev_ctx_host_size; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret; + + /* Update the number of event rings (NER) programmed by the host */ + mhi_ep_mmio_update_ner(mhi_cntrl); + + dev_dbg(dev, "Number of Event rings: %u, HW Event rings: %u\n", + mhi_cntrl->event_rings, mhi_cntrl->hw_event_rings); + + ch_ctx_host_size = sizeof(struct mhi_chan_ctxt) * mhi_cntrl->max_chan; + ev_ctx_host_size = sizeof(struct mhi_event_ctxt) * mhi_cntrl->event_rings; + cmd_ctx_host_size = sizeof(struct mhi_cmd_ctxt) * NR_OF_CMD_RINGS; + + /* Get the channel context base pointer from host */ + mhi_ep_mmio_get_chc_base(mhi_cntrl); + + /* Allocate and map memory for caching host channel context */ + ret = mhi_cntrl->alloc_map(mhi_cntrl, mhi_cntrl->ch_ctx_host_pa, + &mhi_cntrl->ch_ctx_cache_phys, + (void __iomem **) &mhi_cntrl->ch_ctx_cache, + ch_ctx_host_size); + if (ret) { + dev_err(dev, "Failed to allocate and map ch_ctx_cache\n"); + return ret; + } + + /* Get the event context base pointer from host */ + mhi_ep_mmio_get_erc_base(mhi_cntrl); + + /* Allocate and map memory for caching host event context */ + ret = mhi_cntrl->alloc_map(mhi_cntrl, mhi_cntrl->ev_ctx_host_pa, + &mhi_cntrl->ev_ctx_cache_phys, + (void __iomem **) &mhi_cntrl->ev_ctx_cache, + ev_ctx_host_size); + if (ret) { + dev_err(dev, "Failed to allocate and map ev_ctx_cache\n"); + goto err_ch_ctx; + } + + /* Get the command context base pointer from host */ + mhi_ep_mmio_get_crc_base(mhi_cntrl); + + /* Allocate and map memory for caching host command context */ + ret = mhi_cntrl->alloc_map(mhi_cntrl, mhi_cntrl->cmd_ctx_host_pa, + &mhi_cntrl->cmd_ctx_cache_phys, + (void __iomem **) &mhi_cntrl->cmd_ctx_cache, + cmd_ctx_host_size); + if (ret) { + dev_err(dev, "Failed to allocate and map cmd_ctx_cache\n"); + goto err_ev_ctx; + } + + /* Initialize command ring */ + ret = mhi_ep_ring_start(mhi_cntrl, &mhi_cntrl->mhi_cmd->ring, + (union mhi_ep_ring_ctx *)mhi_cntrl->cmd_ctx_cache); + if (ret) { + dev_err(dev, "Failed to start the command ring\n"); + goto err_cmd_ctx; + } + + return ret; + +err_cmd_ctx: + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->cmd_ctx_host_pa, mhi_cntrl->cmd_ctx_cache_phys, + (void __iomem *) mhi_cntrl->cmd_ctx_cache, cmd_ctx_host_size); + +err_ev_ctx: + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->ev_ctx_host_pa, mhi_cntrl->ev_ctx_cache_phys, + (void __iomem *) mhi_cntrl->ev_ctx_cache, ev_ctx_host_size); + +err_ch_ctx: + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->ch_ctx_host_pa, mhi_cntrl->ch_ctx_cache_phys, + (void __iomem *) mhi_cntrl->ch_ctx_cache, ch_ctx_host_size); + + return ret; +} + +static void mhi_ep_free_host_cfg(struct mhi_ep_cntrl *mhi_cntrl) +{ + size_t cmd_ctx_host_size, ch_ctx_host_size, ev_ctx_host_size; + + ch_ctx_host_size = sizeof(struct mhi_chan_ctxt) * mhi_cntrl->max_chan; + ev_ctx_host_size = sizeof(struct mhi_event_ctxt) * mhi_cntrl->event_rings; + cmd_ctx_host_size = sizeof(struct mhi_cmd_ctxt) * NR_OF_CMD_RINGS; + + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->cmd_ctx_host_pa, mhi_cntrl->cmd_ctx_cache_phys, + (void __iomem *) mhi_cntrl->cmd_ctx_cache, cmd_ctx_host_size); + + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->ev_ctx_host_pa, mhi_cntrl->ev_ctx_cache_phys, + (void __iomem *) mhi_cntrl->ev_ctx_cache, ev_ctx_host_size); + + mhi_cntrl->unmap_free(mhi_cntrl, mhi_cntrl->ch_ctx_host_pa, mhi_cntrl->ch_ctx_cache_phys, + (void __iomem *) mhi_cntrl->ch_ctx_cache, ch_ctx_host_size); +} + +static void mhi_ep_enable_int(struct mhi_ep_cntrl *mhi_cntrl) +{ + /* + * Doorbell interrupts are enabled when the corresponding channel gets started. + * Enabling all interrupts here triggers spurious irqs as some of the interrupts + * associated with hw channels always get triggered. + */ + mhi_ep_mmio_enable_ctrl_interrupt(mhi_cntrl); + mhi_ep_mmio_enable_cmdb_interrupt(mhi_cntrl); +} + +static int mhi_ep_enable(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state state; + bool mhi_reset; + u32 count = 0; + int ret; + + /* Wait for Host to set the M0 state */ + do { + msleep(M0_WAIT_DELAY_MS); + mhi_ep_mmio_get_mhi_state(mhi_cntrl, &state, &mhi_reset); + if (mhi_reset) { + /* Clear the MHI reset if host is in reset state */ + mhi_ep_mmio_clear_reset(mhi_cntrl); + dev_info(dev, "Detected Host reset while waiting for M0\n"); + } + count++; + } while (state != MHI_STATE_M0 && count < M0_WAIT_COUNT); + + if (state != MHI_STATE_M0) { + dev_err(dev, "Host failed to enter M0\n"); + return -ETIMEDOUT; + } + + ret = mhi_ep_cache_host_cfg(mhi_cntrl); + if (ret) { + dev_err(dev, "Failed to cache host config\n"); + return ret; + } + + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EE_AMSS); + + /* Enable all interrupts now */ + mhi_ep_enable_int(mhi_cntrl); + + return 0; +} + +static void mhi_ep_cmd_ring_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, cmd_ring_work); + struct mhi_ep_ring *ring = &mhi_cntrl->mhi_cmd->ring; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_ring_element *el; + int ret; + + /* Update the write offset for the ring */ + ret = mhi_ep_update_wr_offset(ring); + if (ret) { + dev_err(dev, "Error updating write offset for ring\n"); + return; + } + + /* Sanity check to make sure there are elements in the ring */ + if (ring->rd_offset == ring->wr_offset) + return; + + /* + * Process command ring element till write offset. In case of an error, just try to + * process next element. + */ + while (ring->rd_offset != ring->wr_offset) { + el = &ring->ring_cache[ring->rd_offset]; + + ret = mhi_ep_process_cmd_ring(ring, el); + if (ret) + dev_err(dev, "Error processing cmd ring element: %zu\n", ring->rd_offset); + + mhi_ep_ring_inc_index(ring); + } +} + +static void mhi_ep_ch_ring_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, ch_ring_work); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_ep_ring_item *itr, *tmp; + struct mhi_ring_element *el; + struct mhi_ep_ring *ring; + struct mhi_ep_chan *chan; + unsigned long flags; + LIST_HEAD(head); + int ret; + + spin_lock_irqsave(&mhi_cntrl->list_lock, flags); + list_splice_tail_init(&mhi_cntrl->ch_db_list, &head); + spin_unlock_irqrestore(&mhi_cntrl->list_lock, flags); + + /* Process each queued channel ring. In case of an error, just process next element. */ + list_for_each_entry_safe(itr, tmp, &head, node) { + list_del(&itr->node); + ring = itr->ring; + + /* Update the write offset for the ring */ + ret = mhi_ep_update_wr_offset(ring); + if (ret) { + dev_err(dev, "Error updating write offset for ring\n"); + kfree(itr); + continue; + } + + /* Sanity check to make sure there are elements in the ring */ + if (ring->rd_offset == ring->wr_offset) { + kfree(itr); + continue; + } + + el = &ring->ring_cache[ring->rd_offset]; + chan = &mhi_cntrl->mhi_chan[ring->ch_id]; + + mutex_lock(&chan->lock); + dev_dbg(dev, "Processing the ring for channel (%u)\n", ring->ch_id); + ret = mhi_ep_process_ch_ring(ring, el); + if (ret) { + dev_err(dev, "Error processing ring for channel (%u): %d\n", + ring->ch_id, ret); + mutex_unlock(&chan->lock); + kfree(itr); + continue; + } + + mutex_unlock(&chan->lock); + kfree(itr); + } +} + +static void mhi_ep_state_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, state_work); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_ep_state_transition *itr, *tmp; + unsigned long flags; + LIST_HEAD(head); + int ret; + + spin_lock_irqsave(&mhi_cntrl->list_lock, flags); + list_splice_tail_init(&mhi_cntrl->st_transition_list, &head); + spin_unlock_irqrestore(&mhi_cntrl->list_lock, flags); + + list_for_each_entry_safe(itr, tmp, &head, node) { + list_del(&itr->node); + dev_dbg(dev, "Handling MHI state transition to %s\n", + mhi_state_str(itr->state)); + + switch (itr->state) { + case MHI_STATE_M0: + ret = mhi_ep_set_m0_state(mhi_cntrl); + if (ret) + dev_err(dev, "Failed to transition to M0 state\n"); + break; + case MHI_STATE_M3: + ret = mhi_ep_set_m3_state(mhi_cntrl); + if (ret) + dev_err(dev, "Failed to transition to M3 state\n"); + break; + default: + dev_err(dev, "Invalid MHI state transition: %d\n", itr->state); + break; + } + kfree(itr); + } +} + +static void mhi_ep_queue_channel_db(struct mhi_ep_cntrl *mhi_cntrl, unsigned long ch_int, + u32 ch_idx) +{ + struct mhi_ep_ring_item *item; + struct mhi_ep_ring *ring; + bool work = !!ch_int; + LIST_HEAD(head); + u32 i; + + /* First add the ring items to a local list */ + for_each_set_bit(i, &ch_int, 32) { + /* Channel index varies for each register: 0, 32, 64, 96 */ + u32 ch_id = ch_idx + i; + + ring = &mhi_cntrl->mhi_chan[ch_id].ring; + item = kzalloc(sizeof(*item), GFP_ATOMIC); + if (!item) + return; + + item->ring = ring; + list_add_tail(&item->node, &head); + } + + /* Now, splice the local list into ch_db_list and queue the work item */ + if (work) { + spin_lock(&mhi_cntrl->list_lock); + list_splice_tail_init(&head, &mhi_cntrl->ch_db_list); + spin_unlock(&mhi_cntrl->list_lock); + + queue_work(mhi_cntrl->wq, &mhi_cntrl->ch_ring_work); + } +} + +/* + * Channel interrupt statuses are contained in 4 registers each of 32bit length. + * For checking all interrupts, we need to loop through each registers and then + * check for bits set. + */ +static void mhi_ep_check_channel_interrupt(struct mhi_ep_cntrl *mhi_cntrl) +{ + u32 ch_int, ch_idx, i; + + /* Bail out if there is no channel doorbell interrupt */ + if (!mhi_ep_mmio_read_chdb_status_interrupts(mhi_cntrl)) + return; + + for (i = 0; i < MHI_MASK_ROWS_CH_DB; i++) { + ch_idx = i * MHI_MASK_CH_LEN; + + /* Only process channel interrupt if the mask is enabled */ + ch_int = mhi_cntrl->chdb[i].status & mhi_cntrl->chdb[i].mask; + if (ch_int) { + mhi_ep_queue_channel_db(mhi_cntrl, ch_int, ch_idx); + mhi_ep_mmio_write(mhi_cntrl, MHI_CHDB_INT_CLEAR_n(i), + mhi_cntrl->chdb[i].status); + } + } +} + +static void mhi_ep_process_ctrl_interrupt(struct mhi_ep_cntrl *mhi_cntrl, + enum mhi_state state) +{ + struct mhi_ep_state_transition *item; + + item = kzalloc(sizeof(*item), GFP_ATOMIC); + if (!item) + return; + + item->state = state; + spin_lock(&mhi_cntrl->list_lock); + list_add_tail(&item->node, &mhi_cntrl->st_transition_list); + spin_unlock(&mhi_cntrl->list_lock); + + queue_work(mhi_cntrl->wq, &mhi_cntrl->state_work); +} + +/* + * Interrupt handler that services interrupts raised by the host writing to + * MHICTRL and Command ring doorbell (CRDB) registers for state change and + * channel interrupts. + */ +static irqreturn_t mhi_ep_irq(int irq, void *data) +{ + struct mhi_ep_cntrl *mhi_cntrl = data; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state state; + u32 int_value; + bool mhi_reset; + + /* Acknowledge the ctrl interrupt */ + int_value = mhi_ep_mmio_read(mhi_cntrl, MHI_CTRL_INT_STATUS); + mhi_ep_mmio_write(mhi_cntrl, MHI_CTRL_INT_CLEAR, int_value); + + /* Check for ctrl interrupt */ + if (FIELD_GET(MHI_CTRL_INT_STATUS_MSK, int_value)) { + dev_dbg(dev, "Processing ctrl interrupt\n"); + mhi_ep_mmio_get_mhi_state(mhi_cntrl, &state, &mhi_reset); + if (mhi_reset) { + dev_info(dev, "Host triggered MHI reset!\n"); + disable_irq_nosync(mhi_cntrl->irq); + schedule_work(&mhi_cntrl->reset_work); + return IRQ_HANDLED; + } + + mhi_ep_process_ctrl_interrupt(mhi_cntrl, state); + } + + /* Check for command doorbell interrupt */ + if (FIELD_GET(MHI_CTRL_INT_STATUS_CRDB_MSK, int_value)) { + dev_dbg(dev, "Processing command doorbell interrupt\n"); + queue_work(mhi_cntrl->wq, &mhi_cntrl->cmd_ring_work); + } + + /* Check for channel interrupts */ + mhi_ep_check_channel_interrupt(mhi_cntrl); + + return IRQ_HANDLED; +} + +static void mhi_ep_abort_transfer(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct mhi_ep_ring *ch_ring, *ev_ring; + struct mhi_result result = {}; + struct mhi_ep_chan *mhi_chan; + int i; + + /* Stop all the channels */ + for (i = 0; i < mhi_cntrl->max_chan; i++) { + mhi_chan = &mhi_cntrl->mhi_chan[i]; + if (!mhi_chan->ring.started) + continue; + + mutex_lock(&mhi_chan->lock); + /* Send channel disconnect status to client drivers */ + if (mhi_chan->xfer_cb) { + result.transaction_status = -ENOTCONN; + result.bytes_xferd = 0; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + } + + mhi_chan->state = MHI_CH_STATE_DISABLED; + mutex_unlock(&mhi_chan->lock); + } + + flush_workqueue(mhi_cntrl->wq); + + /* Destroy devices associated with all channels */ + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_ep_destroy_device); + + /* Stop and reset the transfer rings */ + for (i = 0; i < mhi_cntrl->max_chan; i++) { + mhi_chan = &mhi_cntrl->mhi_chan[i]; + if (!mhi_chan->ring.started) + continue; + + ch_ring = &mhi_cntrl->mhi_chan[i].ring; + mutex_lock(&mhi_chan->lock); + mhi_ep_ring_reset(mhi_cntrl, ch_ring); + mutex_unlock(&mhi_chan->lock); + } + + /* Stop and reset the event rings */ + for (i = 0; i < mhi_cntrl->event_rings; i++) { + ev_ring = &mhi_cntrl->mhi_event[i].ring; + if (!ev_ring->started) + continue; + + mutex_lock(&mhi_cntrl->event_lock); + mhi_ep_ring_reset(mhi_cntrl, ev_ring); + mutex_unlock(&mhi_cntrl->event_lock); + } + + /* Stop and reset the command ring */ + mhi_ep_ring_reset(mhi_cntrl, &mhi_cntrl->mhi_cmd->ring); + + mhi_ep_free_host_cfg(mhi_cntrl); + mhi_ep_mmio_mask_interrupts(mhi_cntrl); + + mhi_cntrl->enabled = false; +} + +static void mhi_ep_reset_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, reset_work); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state cur_state; + int ret; + + mhi_ep_abort_transfer(mhi_cntrl); + + spin_lock_bh(&mhi_cntrl->state_lock); + /* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */ + mhi_ep_mmio_reset(mhi_cntrl); + cur_state = mhi_cntrl->mhi_state; + spin_unlock_bh(&mhi_cntrl->state_lock); + + /* + * Only proceed further if the reset is due to SYS_ERR. The host will + * issue reset during shutdown also and we don't need to do re-init in + * that case. + */ + if (cur_state == MHI_STATE_SYS_ERR) { + mhi_ep_mmio_init(mhi_cntrl); + + /* Set AMSS EE before signaling ready state */ + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EE_AMSS); + + /* All set, notify the host that we are ready */ + ret = mhi_ep_set_ready_state(mhi_cntrl); + if (ret) + return; + + dev_dbg(dev, "READY state notification sent to the host\n"); + + ret = mhi_ep_enable(mhi_cntrl); + if (ret) { + dev_err(dev, "Failed to enable MHI endpoint: %d\n", ret); + return; + } + + enable_irq(mhi_cntrl->irq); + } +} + +/* + * We don't need to do anything special other than setting the MHI SYS_ERR + * state. The host will reset all contexts and issue MHI RESET so that we + * could also recover from error state. + */ +void mhi_ep_handle_syserr(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret; + + ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR); + if (ret) + return; + + /* Signal host that the device went to SYS_ERR state */ + ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_SYS_ERR); + if (ret) + dev_err(dev, "Failed sending SYS_ERR state change event: %d\n", ret); +} + +int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret, i; + + /* + * Mask all interrupts until the state machine is ready. Interrupts will + * be enabled later with mhi_ep_enable(). + */ + mhi_ep_mmio_mask_interrupts(mhi_cntrl); + mhi_ep_mmio_init(mhi_cntrl); + + mhi_cntrl->mhi_event = kzalloc(mhi_cntrl->event_rings * (sizeof(*mhi_cntrl->mhi_event)), + GFP_KERNEL); + if (!mhi_cntrl->mhi_event) + return -ENOMEM; + + /* Initialize command, channel and event rings */ + mhi_ep_ring_init(&mhi_cntrl->mhi_cmd->ring, RING_TYPE_CMD, 0); + for (i = 0; i < mhi_cntrl->max_chan; i++) + mhi_ep_ring_init(&mhi_cntrl->mhi_chan[i].ring, RING_TYPE_CH, i); + for (i = 0; i < mhi_cntrl->event_rings; i++) + mhi_ep_ring_init(&mhi_cntrl->mhi_event[i].ring, RING_TYPE_ER, i); + + mhi_cntrl->mhi_state = MHI_STATE_RESET; + + /* Set AMSS EE before signaling ready state */ + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EE_AMSS); + + /* All set, notify the host that we are ready */ + ret = mhi_ep_set_ready_state(mhi_cntrl); + if (ret) + goto err_free_event; + + dev_dbg(dev, "READY state notification sent to the host\n"); + + ret = mhi_ep_enable(mhi_cntrl); + if (ret) { + dev_err(dev, "Failed to enable MHI endpoint\n"); + goto err_free_event; + } + + enable_irq(mhi_cntrl->irq); + mhi_cntrl->enabled = true; + + return 0; + +err_free_event: + kfree(mhi_cntrl->mhi_event); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_ep_power_up); + +void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl) +{ + if (mhi_cntrl->enabled) + mhi_ep_abort_transfer(mhi_cntrl); + + kfree(mhi_cntrl->mhi_event); + disable_irq(mhi_cntrl->irq); +} +EXPORT_SYMBOL_GPL(mhi_ep_power_down); + +void mhi_ep_suspend_channels(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct mhi_ep_chan *mhi_chan; + u32 tmp; + int i; + + for (i = 0; i < mhi_cntrl->max_chan; i++) { + mhi_chan = &mhi_cntrl->mhi_chan[i]; + + if (!mhi_chan->mhi_dev) + continue; + + mutex_lock(&mhi_chan->lock); + /* Skip if the channel is not currently running */ + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[i].chcfg); + if (FIELD_GET(CHAN_CTX_CHSTATE_MASK, tmp) != MHI_CH_STATE_RUNNING) { + mutex_unlock(&mhi_chan->lock); + continue; + } + + dev_dbg(&mhi_chan->mhi_dev->dev, "Suspending channel\n"); + /* Set channel state to SUSPENDED */ + tmp &= ~CHAN_CTX_CHSTATE_MASK; + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_SUSPENDED); + mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp); + mutex_unlock(&mhi_chan->lock); + } +} + +void mhi_ep_resume_channels(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct mhi_ep_chan *mhi_chan; + u32 tmp; + int i; + + for (i = 0; i < mhi_cntrl->max_chan; i++) { + mhi_chan = &mhi_cntrl->mhi_chan[i]; + + if (!mhi_chan->mhi_dev) + continue; + + mutex_lock(&mhi_chan->lock); + /* Skip if the channel is not currently suspended */ + tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[i].chcfg); + if (FIELD_GET(CHAN_CTX_CHSTATE_MASK, tmp) != MHI_CH_STATE_SUSPENDED) { + mutex_unlock(&mhi_chan->lock); + continue; + } + + dev_dbg(&mhi_chan->mhi_dev->dev, "Resuming channel\n"); + /* Set channel state to RUNNING */ + tmp &= ~CHAN_CTX_CHSTATE_MASK; + tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING); + mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp); + mutex_unlock(&mhi_chan->lock); + } +} + +static void mhi_ep_release_device(struct device *dev) +{ + struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); + + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) + mhi_dev->mhi_cntrl->mhi_dev = NULL; + + /* + * We need to set the mhi_chan->mhi_dev to NULL here since the MHI + * devices for the channels will only get created in mhi_ep_create_device() + * if the mhi_dev associated with it is NULL. + */ + if (mhi_dev->ul_chan) + mhi_dev->ul_chan->mhi_dev = NULL; + + if (mhi_dev->dl_chan) + mhi_dev->dl_chan->mhi_dev = NULL; + + kfree(mhi_dev); +} + +static struct mhi_ep_device *mhi_ep_alloc_device(struct mhi_ep_cntrl *mhi_cntrl, + enum mhi_device_type dev_type) +{ + struct mhi_ep_device *mhi_dev; + struct device *dev; + + mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL); + if (!mhi_dev) + return ERR_PTR(-ENOMEM); + + dev = &mhi_dev->dev; + device_initialize(dev); + dev->bus = &mhi_ep_bus_type; + dev->release = mhi_ep_release_device; + + /* Controller device is always allocated first */ + if (dev_type == MHI_DEVICE_CONTROLLER) + /* for MHI controller device, parent is the bus device (e.g. PCI EPF) */ + dev->parent = mhi_cntrl->cntrl_dev; + else + /* for MHI client devices, parent is the MHI controller device */ + dev->parent = &mhi_cntrl->mhi_dev->dev; + + mhi_dev->mhi_cntrl = mhi_cntrl; + mhi_dev->dev_type = dev_type; + + return mhi_dev; +} + +/* + * MHI channels are always defined in pairs with UL as the even numbered + * channel and DL as odd numbered one. This function gets UL channel (primary) + * as the ch_id and always looks after the next entry in channel list for + * the corresponding DL channel (secondary). + */ +static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id) +{ + struct mhi_ep_chan *mhi_chan = &mhi_cntrl->mhi_chan[ch_id]; + struct device *dev = mhi_cntrl->cntrl_dev; + struct mhi_ep_device *mhi_dev; + int ret; + + /* Check if the channel name is same for both UL and DL */ + if (strcmp(mhi_chan->name, mhi_chan[1].name)) { + dev_err(dev, "UL and DL channel names are not same: (%s) != (%s)\n", + mhi_chan->name, mhi_chan[1].name); + return -EINVAL; + } + + mhi_dev = mhi_ep_alloc_device(mhi_cntrl, MHI_DEVICE_XFER); + if (IS_ERR(mhi_dev)) + return PTR_ERR(mhi_dev); + + /* Configure primary channel */ + mhi_dev->ul_chan = mhi_chan; + get_device(&mhi_dev->dev); + mhi_chan->mhi_dev = mhi_dev; + + /* Configure secondary channel as well */ + mhi_chan++; + mhi_dev->dl_chan = mhi_chan; + get_device(&mhi_dev->dev); + mhi_chan->mhi_dev = mhi_dev; + + /* Channel name is same for both UL and DL */ + mhi_dev->name = mhi_chan->name; + dev_set_name(&mhi_dev->dev, "%s_%s", + dev_name(&mhi_cntrl->mhi_dev->dev), + mhi_dev->name); + + ret = device_add(&mhi_dev->dev); + if (ret) + put_device(&mhi_dev->dev); + + return ret; +} + +static int mhi_ep_destroy_device(struct device *dev, void *data) +{ + struct mhi_ep_device *mhi_dev; + struct mhi_ep_cntrl *mhi_cntrl; + struct mhi_ep_chan *ul_chan, *dl_chan; + + if (dev->bus != &mhi_ep_bus_type) + return 0; + + mhi_dev = to_mhi_ep_device(dev); + mhi_cntrl = mhi_dev->mhi_cntrl; + + /* Only destroy devices created for channels */ + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) + return 0; + + ul_chan = mhi_dev->ul_chan; + dl_chan = mhi_dev->dl_chan; + + if (ul_chan) + put_device(&ul_chan->mhi_dev->dev); + + if (dl_chan) + put_device(&dl_chan->mhi_dev->dev); + + dev_dbg(&mhi_cntrl->mhi_dev->dev, "Destroying device for chan:%s\n", + mhi_dev->name); + + /* Notify the client and remove the device from MHI bus */ + device_del(dev); + put_device(dev); + + return 0; +} + +static int mhi_ep_chan_init(struct mhi_ep_cntrl *mhi_cntrl, + const struct mhi_ep_cntrl_config *config) +{ + const struct mhi_ep_channel_config *ch_cfg; + struct device *dev = mhi_cntrl->cntrl_dev; + u32 chan, i; + int ret = -EINVAL; + + mhi_cntrl->max_chan = config->max_channels; + + /* + * Allocate max_channels supported by the MHI endpoint and populate + * only the defined channels + */ + mhi_cntrl->mhi_chan = kcalloc(mhi_cntrl->max_chan, sizeof(*mhi_cntrl->mhi_chan), + GFP_KERNEL); + if (!mhi_cntrl->mhi_chan) + return -ENOMEM; + + for (i = 0; i < config->num_channels; i++) { + struct mhi_ep_chan *mhi_chan; + + ch_cfg = &config->ch_cfg[i]; + + chan = ch_cfg->num; + if (chan >= mhi_cntrl->max_chan) { + dev_err(dev, "Channel (%u) exceeds maximum available channels (%u)\n", + chan, mhi_cntrl->max_chan); + goto error_chan_cfg; + } + + /* Bi-directional and direction less channels are not supported */ + if (ch_cfg->dir == DMA_BIDIRECTIONAL || ch_cfg->dir == DMA_NONE) { + dev_err(dev, "Invalid direction (%u) for channel (%u)\n", + ch_cfg->dir, chan); + goto error_chan_cfg; + } + + mhi_chan = &mhi_cntrl->mhi_chan[chan]; + mhi_chan->name = ch_cfg->name; + mhi_chan->chan = chan; + mhi_chan->dir = ch_cfg->dir; + mutex_init(&mhi_chan->lock); + } + + return 0; + +error_chan_cfg: + kfree(mhi_cntrl->mhi_chan); + + return ret; +} + +/* + * Allocate channel and command rings here. Event rings will be allocated + * in mhi_ep_power_up() as the config comes from the host. + */ +int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, + const struct mhi_ep_cntrl_config *config) +{ + struct mhi_ep_device *mhi_dev; + int ret; + + if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->mmio || !mhi_cntrl->irq) + return -EINVAL; + + ret = mhi_ep_chan_init(mhi_cntrl, config); + if (ret) + return ret; + + mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS, sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL); + if (!mhi_cntrl->mhi_cmd) { + ret = -ENOMEM; + goto err_free_ch; + } + + INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker); + INIT_WORK(&mhi_cntrl->reset_work, mhi_ep_reset_worker); + INIT_WORK(&mhi_cntrl->cmd_ring_work, mhi_ep_cmd_ring_worker); + INIT_WORK(&mhi_cntrl->ch_ring_work, mhi_ep_ch_ring_worker); + + mhi_cntrl->wq = alloc_workqueue("mhi_ep_wq", 0, 0); + if (!mhi_cntrl->wq) { + ret = -ENOMEM; + goto err_free_cmd; + } + + INIT_LIST_HEAD(&mhi_cntrl->st_transition_list); + INIT_LIST_HEAD(&mhi_cntrl->ch_db_list); + spin_lock_init(&mhi_cntrl->state_lock); + spin_lock_init(&mhi_cntrl->list_lock); + mutex_init(&mhi_cntrl->event_lock); + + /* Set MHI version and AMSS EE before enumeration */ + mhi_ep_mmio_write(mhi_cntrl, EP_MHIVER, config->mhi_version); + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EE_AMSS); + + /* Set controller index */ + ret = ida_alloc(&mhi_ep_cntrl_ida, GFP_KERNEL); + if (ret < 0) + goto err_destroy_wq; + + mhi_cntrl->index = ret; + + irq_set_status_flags(mhi_cntrl->irq, IRQ_NOAUTOEN); + ret = request_irq(mhi_cntrl->irq, mhi_ep_irq, IRQF_TRIGGER_HIGH, + "doorbell_irq", mhi_cntrl); + if (ret) { + dev_err(mhi_cntrl->cntrl_dev, "Failed to request Doorbell IRQ\n"); + goto err_ida_free; + } + + /* Allocate the controller device */ + mhi_dev = mhi_ep_alloc_device(mhi_cntrl, MHI_DEVICE_CONTROLLER); + if (IS_ERR(mhi_dev)) { + dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate controller device\n"); + ret = PTR_ERR(mhi_dev); + goto err_free_irq; + } + + dev_set_name(&mhi_dev->dev, "mhi_ep%u", mhi_cntrl->index); + mhi_dev->name = dev_name(&mhi_dev->dev); + mhi_cntrl->mhi_dev = mhi_dev; + + ret = device_add(&mhi_dev->dev); + if (ret) + goto err_put_dev; + + dev_dbg(&mhi_dev->dev, "MHI EP Controller registered\n"); + + return 0; + +err_put_dev: + put_device(&mhi_dev->dev); +err_free_irq: + free_irq(mhi_cntrl->irq, mhi_cntrl); +err_ida_free: + ida_free(&mhi_ep_cntrl_ida, mhi_cntrl->index); +err_destroy_wq: + destroy_workqueue(mhi_cntrl->wq); +err_free_cmd: + kfree(mhi_cntrl->mhi_cmd); +err_free_ch: + kfree(mhi_cntrl->mhi_chan); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_ep_register_controller); + +/* + * It is expected that the controller drivers will power down the MHI EP stack + * using "mhi_ep_power_down()" before calling this function to unregister themselves. + */ +void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct mhi_ep_device *mhi_dev = mhi_cntrl->mhi_dev; + + destroy_workqueue(mhi_cntrl->wq); + + free_irq(mhi_cntrl->irq, mhi_cntrl); + + kfree(mhi_cntrl->mhi_cmd); + kfree(mhi_cntrl->mhi_chan); + + device_del(&mhi_dev->dev); + put_device(&mhi_dev->dev); + + ida_free(&mhi_ep_cntrl_ida, mhi_cntrl->index); +} +EXPORT_SYMBOL_GPL(mhi_ep_unregister_controller); + +static int mhi_ep_driver_probe(struct device *dev) +{ + struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); + struct mhi_ep_driver *mhi_drv = to_mhi_ep_driver(dev->driver); + struct mhi_ep_chan *ul_chan = mhi_dev->ul_chan; + struct mhi_ep_chan *dl_chan = mhi_dev->dl_chan; + + ul_chan->xfer_cb = mhi_drv->ul_xfer_cb; + dl_chan->xfer_cb = mhi_drv->dl_xfer_cb; + + return mhi_drv->probe(mhi_dev, mhi_dev->id); +} + +static int mhi_ep_driver_remove(struct device *dev) +{ + struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); + struct mhi_ep_driver *mhi_drv = to_mhi_ep_driver(dev->driver); + struct mhi_result result = {}; + struct mhi_ep_chan *mhi_chan; + int dir; + + /* Skip if it is a controller device */ + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) + return 0; + + /* Disconnect the channels associated with the driver */ + for (dir = 0; dir < 2; dir++) { + mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan; + + if (!mhi_chan) + continue; + + mutex_lock(&mhi_chan->lock); + /* Send channel disconnect status to the client driver */ + if (mhi_chan->xfer_cb) { + result.transaction_status = -ENOTCONN; + result.bytes_xferd = 0; + mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); + } + + mhi_chan->state = MHI_CH_STATE_DISABLED; + mhi_chan->xfer_cb = NULL; + mutex_unlock(&mhi_chan->lock); + } + + /* Remove the client driver now */ + mhi_drv->remove(mhi_dev); + + return 0; +} + +int __mhi_ep_driver_register(struct mhi_ep_driver *mhi_drv, struct module *owner) +{ + struct device_driver *driver = &mhi_drv->driver; + + if (!mhi_drv->probe || !mhi_drv->remove) + return -EINVAL; + + /* Client drivers should have callbacks defined for both channels */ + if (!mhi_drv->ul_xfer_cb || !mhi_drv->dl_xfer_cb) + return -EINVAL; + + driver->bus = &mhi_ep_bus_type; + driver->owner = owner; + driver->probe = mhi_ep_driver_probe; + driver->remove = mhi_ep_driver_remove; + + return driver_register(driver); +} +EXPORT_SYMBOL_GPL(__mhi_ep_driver_register); + +void mhi_ep_driver_unregister(struct mhi_ep_driver *mhi_drv) +{ + driver_unregister(&mhi_drv->driver); +} +EXPORT_SYMBOL_GPL(mhi_ep_driver_unregister); + +static int mhi_ep_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); + + return add_uevent_var(env, "MODALIAS=" MHI_EP_DEVICE_MODALIAS_FMT, + mhi_dev->name); +} + +static int mhi_ep_match(struct device *dev, struct device_driver *drv) +{ + struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); + struct mhi_ep_driver *mhi_drv = to_mhi_ep_driver(drv); + const struct mhi_device_id *id; + + /* + * If the device is a controller type then there is no client driver + * associated with it + */ + if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) + return 0; + + for (id = mhi_drv->id_table; id->chan[0]; id++) + if (!strcmp(mhi_dev->name, id->chan)) { + mhi_dev->id = id; + return 1; + } + + return 0; +}; + +struct bus_type mhi_ep_bus_type = { + .name = "mhi_ep", + .dev_name = "mhi_ep", + .match = mhi_ep_match, + .uevent = mhi_ep_uevent, +}; + +static int __init mhi_ep_init(void) +{ + return bus_register(&mhi_ep_bus_type); +} + +static void __exit mhi_ep_exit(void) +{ + bus_unregister(&mhi_ep_bus_type); +} + +postcore_initcall(mhi_ep_init); +module_exit(mhi_ep_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MHI Bus Endpoint stack"); +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>"); |