staging: drop kpc2000 driver

It seems that the old developer is no longer with the company producing
this device, and the company has no plans on getting this out of the
staging directory at all, so let's drop the driver for now as it's
pretty much abandonded.

If someone want to support this and get it out of staging, we can easily
revert this change and bring it back.

Cc: Matt Sickler <matt.sickler@msk4.com>
Link: https://lore.kernel.org/r/20210610183153.2397760-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 0 insertions, 270 deletions

diff --git a/drivers/staging/kpc2000/kpc_dma/dma.c b/drivers/staging/kpc2000/kpc_dma/dma.c
deleted file mode 100644
index e169ac609ba4..000000000000
--- a/drivers/staging/kpc2000/kpc_dma/dma.c
+++ /dev/null
@@ -1,270 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/io.h>
-#include <linux/export.h>
-#include <linux/slab.h>
-#include <linux/platform_device.h>
-#include <linux/fs.h>
-#include <linux/rwsem.h>
-#include "kpc_dma_driver.h"
-
-/**********  IRQ Handlers  **********/
-static
-irqreturn_t  ndd_irq_handler(int irq, void *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;
-}
-
-static
-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) {
-			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->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;
-	dma_addr_t next_handle;
-	dma_addr_t head_handle;
-	unsigned int i;
-	int rv;
-
-	caps = GetEngineCapabilities(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)
-		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, "%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++) {
-		next = dma_pool_alloc(eng->desc_pool, GFP_KERNEL | GFP_DMA, &next_handle);
-		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, "%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;
-
-	// 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)) {
-			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)) {
-			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)) {
-			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;
-	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++) {
-		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) {
-		BUG_ON(!cur);
-		count++;
-		cur = cur->Next;
-	}
-	return count;
-}
-
-void  clear_desc(struct kpc_dma_descriptor *desc)
-{
-	if (!desc)
-		return;
-	desc->DescByteCount         = 0;
-	desc->DescStatusErrorFlags  = 0;
-	desc->DescStatusFlags       = 0;
-	desc->DescUserControlLS     = 0;
-	desc->DescUserControlMS     = 0;
-	desc->DescCardAddrLS        = 0;
-	desc->DescBufferByteCount   = 0;
-	desc->DescCardAddrMS        = 0;
-	desc->DescControlFlags      = 0;
-	desc->DescSystemAddrLS      = 0;
-	desc->DescSystemAddrMS      = 0;
-	desc->acd = NULL;
-}