diff options
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 124 | ||||
| -rw-r--r-- | include/linux/mhi_ep.h | 4 |
2 files changed, 126 insertions, 2 deletions
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index c912daf6dc65..4e82006bd83b 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -11,6 +11,7 @@ #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> @@ -142,6 +143,112 @@ static void mhi_ep_state_worker(struct work_struct *work) } } +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); + } +} + +/* + * 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; + + /* 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_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"); + + /* Check for channel interrupts */ + mhi_ep_check_channel_interrupt(mhi_cntrl); + + return IRQ_HANDLED; +} + static void mhi_ep_release_device(struct device *dev) { struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); @@ -338,7 +445,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_device *mhi_dev; int ret; - if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->mmio) + if (!mhi_cntrl || !mhi_cntrl->cntrl_dev || !mhi_cntrl->mmio || !mhi_cntrl->irq) return -EINVAL; ret = mhi_ep_chan_init(mhi_cntrl, config); @@ -360,6 +467,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, } 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); @@ -375,12 +483,20 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, 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_ida_free; + goto err_free_irq; } dev_set_name(&mhi_dev->dev, "mhi_ep%u", mhi_cntrl->index); @@ -397,6 +513,8 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, 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: @@ -416,6 +534,8 @@ void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl) destroy_workqueue(mhi_cntrl->wq); + free_irq(mhi_cntrl->irq, mhi_cntrl); + kfree(mhi_cntrl->mhi_cmd); kfree(mhi_cntrl->mhi_chan); diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index 2880d2aa88b8..137bd3ee2e43 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -70,6 +70,7 @@ struct mhi_ep_db_info { * @list_lock: Lock for protecting state transition and channel doorbell lists * @state_lock: Lock for protecting state transitions * @st_transition_list: List of state transitions + * @ch_db_list: List of queued channel doorbells * @wq: Dedicated workqueue for handling rings and state changes * @state_work: State transition worker * @raise_irq: CB function for raising IRQ to the host @@ -85,6 +86,7 @@ struct mhi_ep_db_info { * @chdb_offset: Channel doorbell offset set by the host * @erdb_offset: Event ring doorbell offset set by the host * @index: MHI Endpoint controller index + * @irq: IRQ used by the endpoint controller */ struct mhi_ep_cntrl { struct device *cntrl_dev; @@ -109,6 +111,7 @@ struct mhi_ep_cntrl { spinlock_t state_lock; struct list_head st_transition_list; + struct list_head ch_db_list; struct workqueue_struct *wq; struct work_struct state_work; @@ -130,6 +133,7 @@ struct mhi_ep_cntrl { u32 chdb_offset; u32 erdb_offset; u32 index; + int irq; }; /** |