Commit 7df95299 authored by Matt Sickler's avatar Matt Sickler Committed by Greg Kroah-Hartman

staging: kpc2000: Add DMA driver

Add Daktronics DMA driver.  I've added the SPDX license identifiers, Kconfig
entry, and cleaned up as many of the warnings as I could.

The AIO support code will be removed in a future patch.
Signed-off-by: default avatarMatt Sickler <matt.sickler@daktronics.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 52c4dfce
...@@ -44,3 +44,14 @@ config KPC2000_I2C ...@@ -44,3 +44,14 @@ config KPC2000_I2C
If unsure, say N. If unsure, say N.
config KPC2000_DMA
tristate "Daktronics KPC DMA controller"
depends on KPC2000
help
Say Y here if you wish to support the Daktronics DMA controller.
To compile this driver as a module, choose M here: the module
will be called kpc2000_dma
If unsure, say N.
...@@ -3,3 +3,4 @@ ...@@ -3,3 +3,4 @@
obj-$(CONFIG_KPC2000) += kpc2000/ obj-$(CONFIG_KPC2000) += kpc2000/
obj-$(CONFIG_KPC2000_I2C) += kpc_i2c/ obj-$(CONFIG_KPC2000_I2C) += kpc_i2c/
obj-$(CONFIG_KPC2000_SPI) += kpc_spi/ obj-$(CONFIG_KPC2000_SPI) += kpc_spi/
obj-$(CONFIG_KPC2000_DMA) += kpc_dma/
# SPDX-License-Identifier: GPL-2.0
obj-m := kpc_dma.o
kpc_dma-objs += dma.o
kpc_dma-objs += fileops.o
kpc_dma-objs += kpc_dma_driver.o
/* SPDX-License-Identifier: GPL-2.0+ */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <asm/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;
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))
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, "setup_dma_engine: couldn't allocate desc_pool_first!\n");
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 == NULL)
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);
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)){
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 == NULL);
count++;
cur = cur->Next;
}
return count;
}
void clear_desc(struct kpc_dma_descriptor *desc)
{
if (desc == NULL)
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;
}
/* SPDX-License-Identifier: GPL-2.0+ */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/kernel.h> /* printk() */
#include <linux/slab.h> /* kmalloc() */
#include <linux/fs.h> /* everything... */
#include <linux/errno.h> /* error codes */
#include <linux/types.h> /* size_t */
#include <linux/cdev.h>
#include <asm/uaccess.h> /* copy_*_user */
#include <linux/aio.h> /* aio stuff */
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include "kpc_dma_driver.h"
#include "uapi.h"
/********** Helper Functions **********/
static inline
unsigned int count_pages(unsigned long iov_base, size_t iov_len)
{
unsigned long first = (iov_base & PAGE_MASK) >> PAGE_SHIFT;
unsigned long last = ((iov_base+iov_len-1) & PAGE_MASK) >> PAGE_SHIFT;
return last - first + 1;
}
static inline
unsigned int count_parts_for_sge(struct scatterlist *sg)
{
unsigned int sg_length = sg_dma_len(sg);
sg_length += (0x80000-1);
return (sg_length / 0x80000);
}
/********** Transfer Helpers **********/
static
int kpc_dma_transfer(struct dev_private_data *priv, struct kiocb *kcb, unsigned long iov_base, size_t iov_len)
{
unsigned int i = 0;
long rv = 0;
struct kpc_dma_device *ldev;
struct aio_cb_data *acd;
DECLARE_COMPLETION_ONSTACK(done);
u32 desc_needed = 0;
struct scatterlist *sg;
u32 num_descrs_avail;
struct kpc_dma_descriptor *desc;
unsigned int pcnt;
unsigned int p;
u64 card_addr;
u64 dma_addr;
u64 user_ctl;
BUG_ON(priv == NULL);
ldev = priv->ldev;
BUG_ON(ldev == NULL);
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_transfer(priv = [%p], kcb = [%p], iov_base = [%p], iov_len = %ld) ldev = [%p]\n", priv, kcb, (void*)iov_base, iov_len, ldev);
acd = (struct aio_cb_data *) kzalloc(sizeof(struct aio_cb_data), GFP_KERNEL);
if (!acd){
dev_err(&priv->ldev->pldev->dev, "Couldn't kmalloc space for for the aio data\n");
return -ENOMEM;
}
memset(acd, 0x66, sizeof(struct aio_cb_data));
acd->priv = priv;
acd->ldev = priv->ldev;
acd->cpl = &done;
acd->flags = 0;
acd->kcb = kcb;
acd->len = iov_len;
acd->page_count = count_pages(iov_base, iov_len);
// Allocate an array of page pointers
acd->user_pages = kzalloc(sizeof(struct page *) * acd->page_count, GFP_KERNEL);
if (!acd->user_pages){
dev_err(&priv->ldev->pldev->dev, "Couldn't kmalloc space for for the page pointers\n");
rv = -ENOMEM;
goto err_alloc_userpages;
}
// Lock the user buffer pages in memory, and hold on to the page pointers (for the sglist)
down_read(&current->mm->mmap_sem); /* get memory map semaphore */
rv = get_user_pages(iov_base, acd->page_count, FOLL_TOUCH | FOLL_WRITE | FOLL_GET, acd->user_pages, NULL);
up_read(&current->mm->mmap_sem); /* release the semaphore */
if (rv != acd->page_count){
dev_err(&priv->ldev->pldev->dev, "Couldn't get_user_pages (%ld)\n", rv);
goto err_get_user_pages;
}
// Allocate and setup the sg_table (scatterlist entries)
rv = sg_alloc_table_from_pages(&acd->sgt, acd->user_pages, acd->page_count, iov_base & (PAGE_SIZE-1), iov_len, GFP_KERNEL);
if (rv){
dev_err(&priv->ldev->pldev->dev, "Couldn't alloc sg_table (%ld)\n", rv);
goto err_alloc_sg_table;
}
// Setup the DMA mapping for all the sg entries
acd->mapped_entry_count = dma_map_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
if (acd->mapped_entry_count <= 0){
dev_err(&priv->ldev->pldev->dev, "Couldn't dma_map_sg (%d)\n", acd->mapped_entry_count);
goto err_dma_map_sg;
}
// Calculate how many descriptors are actually needed for this transfer.
for_each_sg(acd->sgt.sgl, sg, acd->mapped_entry_count, i){
desc_needed += count_parts_for_sge(sg);
}
lock_engine(ldev);
// Figoure out how many descriptors are available and return an error if there aren't enough
num_descrs_avail = count_descriptors_available(ldev);
dev_dbg(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
if (desc_needed >= ldev->desc_pool_cnt){
dev_warn(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d TOO MANY to ever complete!\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
rv = -EAGAIN;
unlock_engine(ldev);
goto err_descr_too_many;
}
if (desc_needed > num_descrs_avail){
dev_warn(&priv->ldev->pldev->dev, " mapped_entry_count = %d num_descrs_needed = %d num_descrs_avail = %d Too many to complete right now.\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
rv = -EMSGSIZE;
unlock_engine(ldev);
goto err_descr_too_many;
}
// Loop through all the sg table entries and fill out a descriptor for each one.
desc = ldev->desc_next;
card_addr = acd->priv->card_addr;
for_each_sg(acd->sgt.sgl, sg, acd->mapped_entry_count, i){
pcnt = count_parts_for_sge(sg);
for (p = 0 ; p < pcnt ; p++){
// Fill out the descriptor
BUG_ON(desc == NULL);
clear_desc(desc);
if (p != pcnt-1){
desc->DescByteCount = 0x80000;
} else {
desc->DescByteCount = sg_dma_len(sg) - (p * 0x80000);
}
desc->DescBufferByteCount = desc->DescByteCount;
desc->DescControlFlags |= DMA_DESC_CTL_IRQONERR;
if (i == 0 && p == 0)
desc->DescControlFlags |= DMA_DESC_CTL_SOP;
if (i == acd->mapped_entry_count-1 && p == pcnt-1)
desc->DescControlFlags |= DMA_DESC_CTL_EOP | DMA_DESC_CTL_IRQONDONE;
desc->DescCardAddrLS = (card_addr & 0xFFFFFFFF);
desc->DescCardAddrMS = (card_addr >> 32) & 0xF;
card_addr += desc->DescByteCount;
dma_addr = sg_dma_address(sg) + (p * 0x80000);
desc->DescSystemAddrLS = (dma_addr & 0x00000000FFFFFFFF) >> 0;
desc->DescSystemAddrMS = (dma_addr & 0xFFFFFFFF00000000) >> 32;
user_ctl = acd->priv->user_ctl;
if (i == acd->mapped_entry_count-1 && p == pcnt-1){
user_ctl = acd->priv->user_ctl_last;
}
desc->DescUserControlLS = (user_ctl & 0x00000000FFFFFFFF) >> 0;
desc->DescUserControlMS = (user_ctl & 0xFFFFFFFF00000000) >> 32;
if (i == acd->mapped_entry_count-1 && p == pcnt-1)
desc->acd = acd;
dev_dbg(&priv->ldev->pldev->dev, " Filled descriptor %p (acd = %p)\n", desc, desc->acd);
ldev->desc_next = desc->Next;
desc = desc->Next;
}
}
// Send the filled descriptors off to the hardware to process!
SetEngineSWPtr(ldev, ldev->desc_next);
unlock_engine(ldev);
// If this is a synchronous kiocb, we need to put the calling process to sleep until the transfer is complete
if (kcb == NULL || is_sync_kiocb(kcb)){
rv = wait_for_completion_interruptible(&done);
// If the user aborted (rv == -ERESTARTSYS), we're no longer responsible for cleaning up the acd
if (rv == -ERESTARTSYS){
acd->cpl = NULL;
}
if (rv == 0){
rv = acd->len;
kfree(acd);
}
return rv;
}
return -EIOCBQUEUED;
err_descr_too_many:
unlock_engine(ldev);
dma_unmap_sg(&ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, ldev->dir);
sg_free_table(&acd->sgt);
err_dma_map_sg:
err_alloc_sg_table:
for (i = 0 ; i < acd->page_count ; i++){
put_page(acd->user_pages[i]);
}
err_get_user_pages:
kfree(acd->user_pages);
err_alloc_userpages:
kfree(acd);
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_transfer returning with error %ld\n", rv);
return rv;
}
void transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags)
{
unsigned int i;
BUG_ON(acd == NULL);
BUG_ON(acd->user_pages == NULL);
BUG_ON(acd->sgt.sgl == NULL);
BUG_ON(acd->ldev == NULL);
BUG_ON(acd->ldev->pldev == NULL);
dev_dbg(&acd->ldev->pldev->dev, "transfer_complete_cb(acd = [%p])\n", acd);
for (i = 0 ; i < acd->page_count ; i++){
if (!PageReserved(acd->user_pages[i])){
set_page_dirty(acd->user_pages[i]);
}
}
dma_unmap_sg(&acd->ldev->pldev->dev, acd->sgt.sgl, acd->sgt.nents, acd->ldev->dir);
for (i = 0 ; i < acd->page_count ; i++){
put_page(acd->user_pages[i]);
}
sg_free_table(&acd->sgt);
kfree(acd->user_pages);
acd->flags = flags;
if (acd->kcb == NULL || is_sync_kiocb(acd->kcb)){
if (acd->cpl){
complete(acd->cpl);
} else {
// There's no completion, so we're responsible for cleaning up the acd
kfree(acd);
}
} else {
#ifdef CONFIG_KPC_DMA_AIO
aio_complete(acd->kcb, acd->len, acd->flags);
#endif
kfree(acd);
}
}
/********** Fileops **********/
static
int kpc_dma_open(struct inode *inode, struct file *filp)
{
struct dev_private_data *priv;
struct kpc_dma_device *ldev = kpc_dma_lookup_device(iminor(inode));
if (ldev == NULL)
return -ENODEV;
if (! atomic_dec_and_test(&ldev->open_count)){
atomic_inc(&ldev->open_count);
return -EBUSY; /* already open */
}
priv = kzalloc(sizeof(struct dev_private_data), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->ldev = ldev;
filp->private_data = priv;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_open(inode = [%p], filp = [%p]) priv = [%p] ldev = [%p]\n", inode, filp, priv, priv->ldev);
return 0;
}
static
int kpc_dma_close(struct inode *inode, struct file *filp)
{
struct kpc_dma_descriptor *cur;
struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
struct kpc_dma_device *eng = priv->ldev;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_close(inode = [%p], filp = [%p]) priv = [%p], ldev = [%p]\n", inode, filp, priv, priv->ldev);
lock_engine(eng);
stop_dma_engine(eng);
cur = eng->desc_completed->Next;
while (cur != eng->desc_next){
dev_dbg(&eng->pldev->dev, "Aborting descriptor %p (acd = %p)\n", cur, cur->acd);
if (cur->DescControlFlags & DMA_DESC_CTL_EOP){
if (cur->acd)
transfer_complete_cb(cur->acd, 0, ACD_FLAG_ABORT);
}
clear_desc(cur);
eng->desc_completed = cur;
cur = cur->Next;
}
start_dma_engine(eng);
unlock_engine(eng);
atomic_inc(&priv->ldev->open_count); /* release the device */
kfree(priv);
return 0;
}
#ifdef CONFIG_KPC_DMA_AIO
static
int kpc_dma_aio_cancel(struct kiocb *kcb)
{
struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_cancel(kcb = [%p]) priv = [%p], ldev = [%p]\n", kcb, priv, priv->ldev);
return 0;
}
static
ssize_t kpc_dma_aio_read(struct kiocb *kcb, const struct iovec *iov, unsigned long iov_count, loff_t pos)
{
struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_read(kcb = [%p], iov = [%p], iov_count = %ld, pos = %lld) priv = [%p], ldev = [%p]\n", kcb, iov, iov_count, pos, priv, priv->ldev);
if (priv->ldev->dir != DMA_FROM_DEVICE)
return -EMEDIUMTYPE;
if (iov_count != 1){
dev_err(&priv->ldev->pldev->dev, "kpc_dma_aio_read() called with iov_count > 1!\n");
return -EFAULT;
}
if (!is_sync_kiocb(kcb))
kiocb_set_cancel_fn(kcb, kpc_dma_aio_cancel);
return kpc_dma_transfer(priv, kcb, (unsigned long)iov->iov_base, iov->iov_len);
}
static
ssize_t kpc_dma_aio_write(struct kiocb *kcb, const struct iovec *iov, unsigned long iov_count, loff_t pos)
{
struct dev_private_data *priv = (struct dev_private_data *)kcb->ki_filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_aio_write(kcb = [%p], iov = [%p], iov_count = %ld, pos = %lld) priv = [%p], ldev = [%p]\n", kcb, iov, iov_count, pos, priv, priv->ldev);
if (priv->ldev->dir != DMA_TO_DEVICE)
return -EMEDIUMTYPE;
if (iov_count != 1){
dev_err(&priv->ldev->pldev->dev, "kpc_dma_aio_write() called with iov_count > 1!\n");
return -EFAULT;
}
if (!is_sync_kiocb(kcb))
kiocb_set_cancel_fn(kcb, kpc_dma_aio_cancel);
return kpc_dma_transfer(priv, kcb, (unsigned long)iov->iov_base, iov->iov_len);
}
#endif
static
ssize_t kpc_dma_read( struct file *filp, char __user *user_buf, size_t count, loff_t *ppos)
{
struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_read(filp = [%p], user_buf = [%p], count = %zu, ppos = [%p]) priv = [%p], ldev = [%p]\n", filp, user_buf, count, ppos, priv, priv->ldev);
if (priv->ldev->dir != DMA_FROM_DEVICE)
return -EMEDIUMTYPE;
return kpc_dma_transfer(priv, (struct kiocb *)NULL, (unsigned long)user_buf, count);
}
static
ssize_t kpc_dma_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *ppos)
{
struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_write(filp = [%p], user_buf = [%p], count = %zu, ppos = [%p]) priv = [%p], ldev = [%p]\n", filp, user_buf, count, ppos, priv, priv->ldev);
if (priv->ldev->dir != DMA_TO_DEVICE)
return -EMEDIUMTYPE;
return kpc_dma_transfer(priv, (struct kiocb *)NULL, (unsigned long)user_buf, count);
}
static
long kpc_dma_ioctl(struct file *filp, unsigned int ioctl_num, unsigned long ioctl_param)
{
struct dev_private_data *priv = (struct dev_private_data *)filp->private_data;
dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_ioctl(filp = [%p], ioctl_num = 0x%x, ioctl_param = 0x%lx) priv = [%p], ldev = [%p]\n", filp, ioctl_num, ioctl_param, priv, priv->ldev);
switch (ioctl_num){
case KND_IOCTL_SET_CARD_ADDR: priv->card_addr = ioctl_param; return priv->card_addr;
case KND_IOCTL_SET_USER_CTL: priv->user_ctl = ioctl_param; return priv->user_ctl;
case KND_IOCTL_SET_USER_CTL_LAST: priv->user_ctl_last = ioctl_param; return priv->user_ctl_last;
case KND_IOCTL_GET_USER_STS: return priv->user_sts;
}
return -ENOTTY;
}
struct file_operations kpc_dma_fops = {
.owner = THIS_MODULE,
.open = kpc_dma_open,
.release = kpc_dma_close,
.read = kpc_dma_read,
.write = kpc_dma_write,
#ifdef CONFIG_KPC_DMA_AIO
.aio_read = kpc_dma_aio_read,
.aio_write = kpc_dma_aio_write,
#endif
.unlocked_ioctl = kpc_dma_ioctl,
};
/* SPDX-License-Identifier: GPL-2.0+ */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <asm/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"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Matt.Sickler@daktronics.com");
#define KPC_DMA_CHAR_MAJOR UNNAMED_MAJOR
#define KPC_DMA_NUM_MINORS 1 << MINORBITS
static DEFINE_MUTEX(kpc_dma_mtx);
static int assigned_major_num;
static LIST_HEAD(kpc_dma_list);
/********** kpc_dma_list list management **********/
struct kpc_dma_device * kpc_dma_lookup_device(int minor)
{
struct kpc_dma_device *c;
mutex_lock(&kpc_dma_mtx);
list_for_each_entry(c, &kpc_dma_list, list) {
if (c->pldev->id == minor) {
goto out;
}
}
c = NULL; // not-found case
out:
mutex_unlock(&kpc_dma_mtx);
return c;
}
void kpc_dma_add_device(struct kpc_dma_device * ldev)
{
mutex_lock(&kpc_dma_mtx);
list_add(&ldev->list, &kpc_dma_list);
mutex_unlock(&kpc_dma_mtx);
}
void kpc_dma_del_device(struct kpc_dma_device * ldev)
{
mutex_lock(&kpc_dma_mtx);
list_del(&ldev->list);
mutex_unlock(&kpc_dma_mtx);
}
/********** SysFS Attributes **********/
static ssize_t show_engine_regs(struct device *dev, struct device_attribute *attr, char *buf)
{
struct kpc_dma_device *ldev;
struct platform_device *pldev = to_platform_device(dev);
if (!pldev) return 0;
ldev = platform_get_drvdata(pldev);
if (!ldev) return 0;
return scnprintf(buf, PAGE_SIZE,
"EngineControlStatus = 0x%08x\n"
"RegNextDescPtr = 0x%08x\n"
"RegSWDescPtr = 0x%08x\n"
"RegCompletedDescPtr = 0x%08x\n"
"desc_pool_first = %p\n"
"desc_pool_last = %p\n"
"desc_next = %p\n"
"desc_completed = %p\n",
readl(ldev->eng_regs + 1),
readl(ldev->eng_regs + 2),
readl(ldev->eng_regs + 3),
readl(ldev->eng_regs + 4),
ldev->desc_pool_first,
ldev->desc_pool_last,
ldev->desc_next,
ldev->desc_completed
);
}
DEVICE_ATTR(engine_regs, 0444, show_engine_regs, NULL);
static const struct attribute * ndd_attr_list[] = {
&dev_attr_engine_regs.attr,
NULL,
};
struct class *kpc_dma_class;
/********** Platform Driver Functions **********/
static
int kpc_dma_probe(struct platform_device *pldev)
{
struct resource *r = NULL;
int rv = 0;
dev_t dev;
struct kpc_dma_device *ldev = kzalloc(sizeof(struct kpc_dma_device), GFP_KERNEL);
if (!ldev){
dev_err(&pldev->dev, "kpc_dma_probe: unable to kzalloc space for kpc_dma_device\n");
rv = -ENOMEM;
goto err_rv;
}
dev_dbg(&pldev->dev, "kpc_dma_probe(pldev = [%p]) ldev = [%p]\n", pldev, ldev);
INIT_LIST_HEAD(&ldev->list);
ldev->pldev = pldev;
platform_set_drvdata(pldev, ldev);
atomic_set(&ldev->open_count, 1);
mutex_init(&ldev->sem);
lock_engine(ldev);
// Get Engine regs resource
r = platform_get_resource(pldev, IORESOURCE_MEM, 0);
if (!r){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: didn't get the engine regs resource!\n");
rv = -ENXIO;
goto err_kfree;
}
ldev->eng_regs = ioremap_nocache(r->start, resource_size(r));
if (!ldev->eng_regs){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: failed to ioremap engine regs!\n");
rv = -ENXIO;
goto err_kfree;
}
r = platform_get_resource(pldev, IORESOURCE_IRQ, 0);
if (!r){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: didn't get the IRQ resource!\n");
rv = -ENXIO;
goto err_kfree;
}
ldev->irq = r->start;
// Setup miscdev struct
dev = MKDEV(assigned_major_num, pldev->id);
ldev->kpc_dma_dev = device_create(kpc_dma_class, &pldev->dev, dev, ldev, "kpc_dma%d", pldev->id);
if (IS_ERR(ldev->kpc_dma_dev)){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: device_create failed: %d\n", rv);
goto err_kfree;
}
// Setup the DMA engine
rv = setup_dma_engine(ldev, 30);
if (rv){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: failed to setup_dma_engine: %d\n", rv);
goto err_misc_dereg;
}
// Setup the sysfs files
rv = sysfs_create_files(&(ldev->pldev->dev.kobj), ndd_attr_list);
if (rv){
dev_err(&ldev->pldev->dev, "kpc_dma_probe: Failed to add sysfs files: %d\n", rv);
goto err_destroy_eng;
}
kpc_dma_add_device(ldev);
return 0;
err_destroy_eng:
destroy_dma_engine(ldev);
err_misc_dereg:
device_destroy(kpc_dma_class, dev);
err_kfree:
kfree(ldev);
err_rv:
return rv;
}
static
int kpc_dma_remove(struct platform_device *pldev)
{
struct kpc_dma_device *ldev = platform_get_drvdata(pldev);
if (!ldev)
return -ENXIO;
dev_dbg(&ldev->pldev->dev, "kpc_dma_remove(pldev = [%p]) ldev = [%p]\n", pldev, ldev);
lock_engine(ldev);
sysfs_remove_files(&(ldev->pldev->dev.kobj), ndd_attr_list);
destroy_dma_engine(ldev);
kpc_dma_del_device(ldev);
device_destroy(kpc_dma_class, MKDEV(assigned_major_num, ldev->pldev->id));
kfree(ldev);
return 0;
}
/********** Driver Functions **********/
struct platform_driver kpc_dma_plat_driver_i = {
.probe = kpc_dma_probe,
.remove = kpc_dma_remove,
.driver = {
.name = KP_DRIVER_NAME_DMA_CONTROLLER,
.owner = THIS_MODULE,
},
};
static
int __init kpc_dma_driver_init(void)
{
int err;
err = __register_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma", &kpc_dma_fops);
if (err < 0){
pr_err("Can't allocate a major number (%d) for kpc_dma (err = %d)\n", KPC_DMA_CHAR_MAJOR, err);
goto fail_chrdev_register;
}
assigned_major_num = err;
kpc_dma_class = class_create(THIS_MODULE, "kpc_dma");
err = PTR_ERR(kpc_dma_class);
if (IS_ERR(kpc_dma_class)){
pr_err("Can't create class kpc_dma (err = %d)\n", err);
goto fail_class_create;
}
err = platform_driver_register(&kpc_dma_plat_driver_i);
if (err){
pr_err("Can't register platform driver for kpc_dma (err = %d)\n", err);
goto fail_platdriver_register;
}
return err;
fail_platdriver_register:
class_destroy(kpc_dma_class);
fail_class_create:
__unregister_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma");
fail_chrdev_register:
return err;
}
module_init(kpc_dma_driver_init);
static
void __exit kpc_dma_driver_exit(void)
{
platform_driver_unregister(&kpc_dma_plat_driver_i);
class_destroy(kpc_dma_class);
__unregister_chrdev(KPC_DMA_CHAR_MAJOR, 0, KPC_DMA_NUM_MINORS, "kpc_dma");
}
module_exit(kpc_dma_driver_exit);
/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef KPC_DMA_DRIVER_H
#define KPC_DMA_DRIVER_H
#include <linux/platform_device.h>
#include <linux/cdev.h>
#include <linux/kfifo.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/miscdevice.h>
#include <linux/rwsem.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/aio.h>
#include <linux/bitops.h>
#include "../kpc.h"
struct kp2000_device;
struct kpc_dma_device {
struct list_head list;
struct platform_device *pldev;
u32 __iomem *eng_regs;
struct device *kpc_dma_dev;
struct kobject kobj;
char name[16];
int dir; // DMA_FROM_DEVICE || DMA_TO_DEVICE
struct mutex sem;
unsigned int irq;
struct work_struct irq_work;
atomic_t open_count;
size_t accumulated_bytes;
u32 accumulated_flags;
// Descriptor "Pool" housekeeping
u32 desc_pool_cnt;
struct dma_pool *desc_pool;
struct kpc_dma_descriptor *desc_pool_first;
struct kpc_dma_descriptor *desc_pool_last;
struct kpc_dma_descriptor *desc_next;
struct kpc_dma_descriptor *desc_completed;
};
struct dev_private_data {
struct kpc_dma_device *ldev;
u64 card_addr;
u64 user_ctl;
u64 user_ctl_last;
u64 user_sts;
};
struct kpc_dma_device * kpc_dma_lookup_device(int minor);
extern struct file_operations kpc_dma_fops;
#define ENG_CAP_PRESENT 0x00000001
#define ENG_CAP_DIRECTION 0x00000002
#define ENG_CAP_TYPE_MASK 0x000000F0
#define ENG_CAP_NUMBER_MASK 0x0000FF00
#define ENG_CAP_CARD_ADDR_SIZE_MASK 0x007F0000
#define ENG_CAP_DESC_MAX_BYTE_CNT_MASK 0x3F000000
#define ENG_CAP_PERF_SCALE_MASK 0xC0000000
#define ENG_CTL_IRQ_ENABLE BIT(0)
#define ENG_CTL_IRQ_ACTIVE BIT(1)
#define ENG_CTL_DESC_COMPLETE BIT(2)
#define ENG_CTL_DESC_ALIGN_ERR BIT(3)
#define ENG_CTL_DESC_FETCH_ERR BIT(4)
#define ENG_CTL_SW_ABORT_ERR BIT(5)
#define ENG_CTL_DESC_CHAIN_END BIT(7)
#define ENG_CTL_DMA_ENABLE BIT(8)
#define ENG_CTL_DMA_RUNNING BIT(10)
#define ENG_CTL_DMA_WAITING BIT(11)
#define ENG_CTL_DMA_WAITING_PERSIST BIT(12)
#define ENG_CTL_DMA_RESET_REQUEST BIT(14)
#define ENG_CTL_DMA_RESET BIT(15)
#define ENG_CTL_DESC_FETCH_ERR_CLASS_MASK 0x700000
struct aio_cb_data {
struct dev_private_data *priv;
struct kpc_dma_device *ldev;
struct completion *cpl;
unsigned char flags;
struct kiocb *kcb;
size_t len;
unsigned int page_count;
struct page **user_pages;
struct sg_table sgt;
int mapped_entry_count;
};
#define ACD_FLAG_DONE 0
#define ACD_FLAG_ABORT 1
#define ACD_FLAG_ENG_ACCUM_ERROR 4
#define ACD_FLAG_ENG_ACCUM_SHORT 5
struct kpc_dma_descriptor {
struct {
volatile u32 DescByteCount :20;
volatile u32 DescStatusErrorFlags :4;
volatile u32 DescStatusFlags :8;
};
volatile u32 DescUserControlLS;
volatile u32 DescUserControlMS;
volatile u32 DescCardAddrLS;
struct {
volatile u32 DescBufferByteCount :20;
volatile u32 DescCardAddrMS :4;
volatile u32 DescControlFlags :8;
};
volatile u32 DescSystemAddrLS;
volatile u32 DescSystemAddrMS;
volatile u32 DescNextDescPtr;
dma_addr_t MyDMAAddr;
struct kpc_dma_descriptor *Next;
struct aio_cb_data *acd;
} __attribute__((packed));
// DescControlFlags:
#define DMA_DESC_CTL_SOP BIT(7)
#define DMA_DESC_CTL_EOP BIT(6)
#define DMA_DESC_CTL_AFIFO BIT(2)
#define DMA_DESC_CTL_IRQONERR BIT(1)
#define DMA_DESC_CTL_IRQONDONE BIT(0)
// DescStatusFlags:
#define DMA_DESC_STS_SOP BIT(7)
#define DMA_DESC_STS_EOP BIT(6)
#define DMA_DESC_STS_ERROR BIT(4)
#define DMA_DESC_STS_USMSZ BIT(3)
#define DMA_DESC_STS_USLSZ BIT(2)
#define DMA_DESC_STS_SHORT BIT(1)
#define DMA_DESC_STS_COMPLETE BIT(0)
// DescStatusErrorFlags:
#define DMA_DESC_ESTS_ECRC BIT(2)
#define DMA_DESC_ESTS_POISON BIT(1)
#define DMA_DESC_ESTS_UNSUCCESSFUL BIT(0)
#define DMA_DESC_ALIGNMENT 0x20
static inline
u32 GetEngineCapabilities(struct kpc_dma_device *eng)
{
return readl(eng->eng_regs + 0);
}
static inline
void WriteEngineControl(struct kpc_dma_device *eng, u32 value)
{
writel(value, eng->eng_regs + 1);
}
static inline
u32 GetEngineControl(struct kpc_dma_device *eng)
{
return readl(eng->eng_regs + 1);
}
static inline
void SetClearEngineControl(struct kpc_dma_device *eng, u32 set_bits, u32 clear_bits)
{
u32 val = GetEngineControl(eng);
val |= set_bits;
val &= ~clear_bits;
WriteEngineControl(eng, val);
}
static inline
void SetEngineNextPtr(struct kpc_dma_device *eng, struct kpc_dma_descriptor * desc)
{
writel(desc->MyDMAAddr, eng->eng_regs + 2);
}
static inline
void SetEngineSWPtr(struct kpc_dma_device *eng, struct kpc_dma_descriptor * desc)
{
writel(desc->MyDMAAddr, eng->eng_regs + 3);
}
static inline
void ClearEngineCompletePtr(struct kpc_dma_device *eng)
{
writel(0, eng->eng_regs + 4);
}
static inline
u32 GetEngineCompletePtr(struct kpc_dma_device *eng)
{
return readl(eng->eng_regs + 4);
}
static inline
void lock_engine(struct kpc_dma_device *eng)
{
BUG_ON(eng == NULL);
mutex_lock(&eng->sem);
}
static inline
void unlock_engine(struct kpc_dma_device *eng)
{
BUG_ON(eng == NULL);
mutex_unlock(&eng->sem);
}
/// Shared Functions
void start_dma_engine(struct kpc_dma_device *eng);
int setup_dma_engine(struct kpc_dma_device *eng, u32 desc_cnt);
void stop_dma_engine(struct kpc_dma_device *eng);
void destroy_dma_engine(struct kpc_dma_device *eng);
void clear_desc(struct kpc_dma_descriptor *desc);
int count_descriptors_available(struct kpc_dma_device *eng);
void transfer_complete_cb(struct aio_cb_data *acd, size_t xfr_count, u32 flags);
#endif /* KPC_DMA_DRIVER_H */
/* SPDX-License-Identifier: GPL-2.0+ */
#ifndef KPC_DMA_DRIVER_UAPI_H_
#define KPC_DMA_DRIVER_UAPI_H_
#include <linux/ioctl.h>
#define KND_IOCTL_SET_CARD_ADDR _IOW('k', 1, __u32)
#define KND_IOCTL_SET_USER_CTL _IOW('k', 2, __u64)
#define KND_IOCTL_SET_USER_CTL_LAST _IOW('k', 4, __u64)
#define KND_IOCTL_GET_USER_STS _IOR('k', 3, __u64)
#endif /* KPC_DMA_DRIVER_UAPI_H_ */
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