diff options
Diffstat (limited to 'drivers/staging/kpc2000/kpc_dma/dma.c')
-rw-r--r-- | drivers/staging/kpc2000/kpc_dma/dma.c | 142 |
1 files changed, 70 insertions, 72 deletions
diff --git a/drivers/staging/kpc2000/kpc_dma/dma.c b/drivers/staging/kpc2000/kpc_dma/dma.c index 6959bac11388..51a4dd534a0d 100644 --- a/drivers/staging/kpc2000/kpc_dma/dma.c +++ b/drivers/staging/kpc2000/kpc_dma/dma.c @@ -2,7 +2,7 @@ #include <linux/init.h> #include <linux/module.h> #include <linux/types.h> -#include <asm/io.h> +#include <linux/io.h> #include <linux/export.h> #include <linux/slab.h> #include <linux/platform_device.h> @@ -14,11 +14,11 @@ static irqreturn_t ndd_irq_handler(int irq, void *dev_id) { - struct kpc_dma_device *ldev = (struct kpc_dma_device*)dev_id; - + struct kpc_dma_device *ldev = (struct kpc_dma_device *)dev_id; + if ((GetEngineControl(ldev) & ENG_CTL_IRQ_ACTIVE) || (ldev->desc_completed->MyDMAAddr != GetEngineCompletePtr(ldev))) schedule_work(&ldev->irq_work); - + return IRQ_HANDLED; } @@ -27,217 +27,215 @@ void ndd_irq_worker(struct work_struct *ws) { struct kpc_dma_descriptor *cur; struct kpc_dma_device *eng = container_of(ws, struct kpc_dma_device, irq_work); + lock_engine(eng); - + if (GetEngineCompletePtr(eng) == 0) goto out; - + if (eng->desc_completed->MyDMAAddr == GetEngineCompletePtr(eng)) goto out; - + cur = eng->desc_completed; do { cur = cur->Next; dev_dbg(&eng->pldev->dev, "Handling completed descriptor %p (acd = %p)\n", cur, cur->acd); BUG_ON(cur == eng->desc_next); // Ordering failure. - - if (cur->DescControlFlags & DMA_DESC_CTL_SOP){ + + if (cur->DescControlFlags & DMA_DESC_CTL_SOP) { eng->accumulated_bytes = 0; eng->accumulated_flags = 0; } - + eng->accumulated_bytes += cur->DescByteCount; if (cur->DescStatusFlags & DMA_DESC_STS_ERROR) eng->accumulated_flags |= ACD_FLAG_ENG_ACCUM_ERROR; - + if (cur->DescStatusFlags & DMA_DESC_STS_SHORT) eng->accumulated_flags |= ACD_FLAG_ENG_ACCUM_SHORT; - - if (cur->DescControlFlags & DMA_DESC_CTL_EOP){ + + if (cur->DescControlFlags & DMA_DESC_CTL_EOP) { if (cur->acd) transfer_complete_cb(cur->acd, eng->accumulated_bytes, eng->accumulated_flags | ACD_FLAG_DONE); } - + eng->desc_completed = cur; } while (cur->MyDMAAddr != GetEngineCompletePtr(eng)); - + out: SetClearEngineControl(eng, ENG_CTL_IRQ_ACTIVE, 0); - + unlock_engine(eng); } - /********** DMA Engine Init/Teardown **********/ void start_dma_engine(struct kpc_dma_device *eng) { eng->desc_next = eng->desc_pool_first; eng->desc_completed = eng->desc_pool_last; - + // Setup the engine pointer registers SetEngineNextPtr(eng, eng->desc_pool_first); SetEngineSWPtr(eng, eng->desc_pool_first); ClearEngineCompletePtr(eng); - + WriteEngineControl(eng, ENG_CTL_DMA_ENABLE | ENG_CTL_IRQ_ENABLE); } int setup_dma_engine(struct kpc_dma_device *eng, u32 desc_cnt) { u32 caps; - struct kpc_dma_descriptor * cur; - struct kpc_dma_descriptor * next; + struct kpc_dma_descriptor *cur; + struct kpc_dma_descriptor *next; dma_addr_t next_handle; dma_addr_t head_handle; unsigned int i; int rv; - dev_dbg(&eng->pldev->dev, "Setting up DMA engine [%p]\n", eng); - + caps = GetEngineCapabilities(eng); - - if (WARN(!(caps & ENG_CAP_PRESENT), "setup_dma_engine() called for DMA Engine at %p which isn't present in hardware!\n", eng)) + + if (WARN(!(caps & ENG_CAP_PRESENT), "%s() called for DMA Engine at %p which isn't present in hardware!\n", __func__, eng)) return -ENXIO; - - if (caps & ENG_CAP_DIRECTION){ + + if (caps & ENG_CAP_DIRECTION) { eng->dir = DMA_FROM_DEVICE; } else { eng->dir = DMA_TO_DEVICE; } - + eng->desc_pool_cnt = desc_cnt; eng->desc_pool = dma_pool_create("KPC DMA Descriptors", &eng->pldev->dev, sizeof(struct kpc_dma_descriptor), DMA_DESC_ALIGNMENT, 4096); - + eng->desc_pool_first = dma_pool_alloc(eng->desc_pool, GFP_KERNEL | GFP_DMA, &head_handle); - if (!eng->desc_pool_first){ - dev_err(&eng->pldev->dev, "setup_dma_engine: couldn't allocate desc_pool_first!\n"); + if (!eng->desc_pool_first) { + dev_err(&eng->pldev->dev, "%s: couldn't allocate desc_pool_first!\n", __func__); dma_pool_destroy(eng->desc_pool); return -ENOMEM; } - + eng->desc_pool_first->MyDMAAddr = head_handle; clear_desc(eng->desc_pool_first); - + cur = eng->desc_pool_first; - for (i = 1 ; i < eng->desc_pool_cnt ; i++){ + for (i = 1 ; i < eng->desc_pool_cnt ; i++) { next = dma_pool_alloc(eng->desc_pool, GFP_KERNEL | GFP_DMA, &next_handle); - if (next == NULL) + if (!next) goto done_alloc; - + clear_desc(next); next->MyDMAAddr = next_handle; - + cur->DescNextDescPtr = next_handle; cur->Next = next; cur = next; } - + done_alloc: // Link the last descriptor back to the first, so it's a circular linked list cur->Next = eng->desc_pool_first; cur->DescNextDescPtr = eng->desc_pool_first->MyDMAAddr; - + eng->desc_pool_last = cur; eng->desc_completed = eng->desc_pool_last; - + // Setup work queue INIT_WORK(&eng->irq_work, ndd_irq_worker); - + // Grab IRQ line rv = request_irq(eng->irq, ndd_irq_handler, IRQF_SHARED, KP_DRIVER_NAME_DMA_CONTROLLER, eng); - if (rv){ - dev_err(&eng->pldev->dev, "setup_dma_engine: failed to request_irq: %d\n", rv); + if (rv) { + dev_err(&eng->pldev->dev, "%s: failed to request_irq: %d\n", __func__, rv); return rv; } - + // Turn on the engine! start_dma_engine(eng); unlock_engine(eng); - + return 0; } void stop_dma_engine(struct kpc_dma_device *eng) { unsigned long timeout; - dev_dbg(&eng->pldev->dev, "Destroying DMA engine [%p]\n", eng); - + // Disable the descriptor engine WriteEngineControl(eng, 0); - + // Wait for descriptor engine to finish current operaion timeout = jiffies + (HZ / 2); - while (GetEngineControl(eng) & ENG_CTL_DMA_RUNNING){ - if (time_after(jiffies, timeout)){ + while (GetEngineControl(eng) & ENG_CTL_DMA_RUNNING) { + if (time_after(jiffies, timeout)) { dev_crit(&eng->pldev->dev, "DMA_RUNNING still asserted!\n"); break; } } - + // Request a reset WriteEngineControl(eng, ENG_CTL_DMA_RESET_REQUEST); - + // Wait for reset request to be processed timeout = jiffies + (HZ / 2); - while (GetEngineControl(eng) & (ENG_CTL_DMA_RUNNING | ENG_CTL_DMA_RESET_REQUEST)){ - if (time_after(jiffies, timeout)){ + while (GetEngineControl(eng) & (ENG_CTL_DMA_RUNNING | ENG_CTL_DMA_RESET_REQUEST)) { + if (time_after(jiffies, timeout)) { dev_crit(&eng->pldev->dev, "ENG_CTL_DMA_RESET_REQUEST still asserted!\n"); break; } } - + // Request a reset WriteEngineControl(eng, ENG_CTL_DMA_RESET); - + // And wait for reset to complete timeout = jiffies + (HZ / 2); - while (GetEngineControl(eng) & ENG_CTL_DMA_RESET){ - if (time_after(jiffies, timeout)){ + while (GetEngineControl(eng) & ENG_CTL_DMA_RESET) { + if (time_after(jiffies, timeout)) { dev_crit(&eng->pldev->dev, "DMA_RESET still asserted!\n"); break; } } - + // Clear any persistent bits just to make sure there is no residue from the reset SetClearEngineControl(eng, (ENG_CTL_IRQ_ACTIVE | ENG_CTL_DESC_COMPLETE | ENG_CTL_DESC_ALIGN_ERR | ENG_CTL_DESC_FETCH_ERR | ENG_CTL_SW_ABORT_ERR | ENG_CTL_DESC_CHAIN_END | ENG_CTL_DMA_WAITING_PERSIST), 0); - + // Reset performance counters - + // Completely disable the engine WriteEngineControl(eng, 0); } void destroy_dma_engine(struct kpc_dma_device *eng) { - struct kpc_dma_descriptor * cur; + struct kpc_dma_descriptor *cur; dma_addr_t cur_handle; unsigned int i; - + stop_dma_engine(eng); - + cur = eng->desc_pool_first; cur_handle = eng->desc_pool_first->MyDMAAddr; - - for (i = 0 ; i < eng->desc_pool_cnt ; i++){ + + for (i = 0 ; i < eng->desc_pool_cnt ; i++) { struct kpc_dma_descriptor *next = cur->Next; dma_addr_t next_handle = cur->DescNextDescPtr; + dma_pool_free(eng->desc_pool, cur, cur_handle); cur_handle = next_handle; cur = next; } - + dma_pool_destroy(eng->desc_pool); - + free_irq(eng->irq, eng); } - - /********** Helper Functions **********/ int count_descriptors_available(struct kpc_dma_device *eng) { u32 count = 0; struct kpc_dma_descriptor *cur = eng->desc_next; - while (cur != eng->desc_completed){ + + while (cur != eng->desc_completed) { BUG_ON(cur == NULL); count++; cur = cur->Next; @@ -247,7 +245,7 @@ int count_descriptors_available(struct kpc_dma_device *eng) void clear_desc(struct kpc_dma_descriptor *desc) { - if (desc == NULL) + if (!desc) return; desc->DescByteCount = 0; desc->DescStatusErrorFlags = 0; |