// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) Freescale Semicondutor, Inc. 2007, 2008.
* Copyright (C) Semihalf 2009
* Copyright (C) Ilya Yanok, Emcraft Systems 2010
* Copyright (C) Alexander Popov, Promcontroller 2014
* Copyright (C) Mario Six, Guntermann & Drunck GmbH, 2016
*
* Written by Piotr Ziecik <kosmo@semihalf.com>. Hardware description
* (defines, structures and comments) was taken from MPC5121 DMA driver
* written by Hongjun Chen <hong-jun.chen@freescale.com>.
*
* Approved as OSADL project by a majority of OSADL members and funded
* by OSADL membership fees in 2009; for details see www.osadl.org.
*/
/*
* MPC512x and MPC8308 DMA driver. It supports memory to memory data transfers
* (tested using dmatest module) and data transfers between memory and
* peripheral I/O memory by means of slave scatter/gather with these
* limitations:
* - chunked transfers (described by s/g lists with more than one item) are
* refused as long as proper support for scatter/gather is missing
* - transfers on MPC8308 always start from software as this SoC does not have
* external request lines for peripheral flow control
* - memory <-> I/O memory transfer chunks of sizes of 1, 2, 4, 16 (for
* MPC512x), and 32 bytes are supported, and, consequently, source
* addresses and destination addresses must be aligned accordingly;
* furthermore, for MPC512x SoCs, the transfer size must be aligned on
* (chunk size * maxburst)
*/
#include <linux/module.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/random.h>
#include "dmaengine.h"
/* Number of DMA Transfer descriptors allocated per channel */
#define MPC_DMA_DESCRIPTORS 64
/* Macro definitions */
#define MPC_DMA_TCD_OFFSET 0x1000
/*
* Maximum channel counts for individual hardware variants
* and the maximum channel count over all supported controllers,
* used for data structure size
*/
#define MPC8308_DMACHAN_MAX 16
#define MPC512x_DMACHAN_MAX 64
#define MPC_DMA_CHANNELS 64
/* Arbitration mode of group and channel */
#define MPC_DMA_DMACR_EDCG (1 << 31)
#define MPC_DMA_DMACR_ERGA (1 << 3)
#define MPC_DMA_DMACR_ERCA (1 << 2)
/* Error codes */
#define MPC_DMA_DMAES_VLD (1 << 31)
#define MPC_DMA_DMAES_GPE (1 << 15)
#define MPC_DMA_DMAES_CPE (1 << 14)
#define MPC_DMA_DMAES_ERRCHN(err) \
(((err) >> 8) & 0x3f)
#define MPC_DMA_DMAES_SAE (1 << 7)
#define MPC_DMA_DMAES_SOE (1 << 6)
#define MPC_DMA_DMAES_DAE (1 << 5)
#define MPC_DMA_DMAES_DOE (1 << 4)
#define MPC_DMA_DMAES_NCE (1 << 3)
#define MPC_DMA_DMAES_SGE (1 << 2)
#define MPC_DMA_DMAES_SBE (1 << 1)
#define MPC_DMA_DMAES_DBE (1 << 0)
#define MPC_DMA_DMAGPOR_SNOOP_ENABLE (1 << 6)
#define MPC_DMA_TSIZE_1 0x00
#define MPC_DMA_TSIZE_2 0x01
#define MPC_DMA_TSIZE_4 0x02
#define MPC_DMA_TSIZE_16 0x04
#define MPC_DMA_TSIZE_32 0x05
/* MPC5121 DMA engine registers */
struct __attribute__ ((__packed__)) mpc_dma_regs {
/* 0x00 */
u32 dmacr; /* DMA control register */
u32 dmaes; /* DMA error status */
/* 0x08 */
u32 dmaerqh; /* DMA enable request high(channels 63~32) */
u32 dmaerql; /* DMA enable request low(channels 31~0) */
u32 dmaeeih; /* DMA enable error interrupt high(ch63~32) */
u32 dmaeeil; /* DMA enable error interrupt low(ch31~0) */
/* 0x18 */
u8 dmaserq; /* DMA set enable request */
u8 dmacerq; /* DMA clear enable request */
u8 dmaseei; /* DMA set enable error interrupt */
u8 dmaceei; /* DMA clear enable error interrupt */
/* 0x1c */
u8 dmacint; /* DMA clear interrupt request */
u8 dmacerr; /* DMA clear error */
u8 dmassrt; /* DMA set start bit */
u8 dmacdne; /* DMA clear DONE status bit */
/* 0x20 */
u32 dmainth; /* DMA interrupt request high(ch63~32) */
u32 dmaintl; /* DMA interrupt request low(ch31~0) */
u32 dmaerrh; /* DMA error high(ch63~32) */
u32 dmaerrl; /* DMA error low(ch31~0) */
/* 0x30 */
u32 dmahrsh; /* DMA hw request status high(ch63~32) */
u32 dmahrsl; /* DMA hardware request status low(ch31~0) */
union {
u32 dmaihsa; /* DMA interrupt high select AXE(ch63~32) */
u32 dmagpor; /* (General purpose register on MPC8308) */
};
u32 dmailsa; /* DMA interrupt low select AXE(ch31~0) */
/* 0x40 ~ 0xff */
u32 reserve0[48]; /* Reserved */
/* 0x100 */
u8 dchpri[MPC_DMA_CHANNELS];
/* DMA channels(0~63) priority */
};
struct __attribute__ ((__packed__)) mpc_dma_tcd {
/* 0x00 */
u32 saddr; /* Source address */
u32 smod:5; /* Source address modulo */
u32 ssize:3; /* Source data transfer size */
u32 dmod:5; /* Destination address modulo */
u32 dsize:3; /* Destination data transfer size */
u32 soff:16; /* Signed source address offset */
/* 0x08 */
u32 nbytes; /* Inner "minor" byte count */
u32 slast; /* Last source address adjustment */
u32 daddr; /* Destination address */
/* 0x14 */
u32 citer_elink:1; /* Enable channel-to-channel linking on
* minor loop complete
*/
u32 citer_linkch:6; /* Link channel for minor loop complete */
u32 citer:9; /* Current "major" iteration count */
u32 doff:16; /* Signed destination address offset */
/* 0x18 */
u32 dlast_sga; /* Last Destination address adjustment/scatter
* gather address
*/
/* 0x1c */
u32 biter_elink:1; /* Enable channel-to-channel linking on major
* loop complete
*/
u32 biter_linkch:6;
u32 biter:9; /* Beginning "major" iteration count */
u32 bwc:2; /* Bandwidth control */
u32 major_linkch:6; /* Link channel number */
u32 done:1; /* Channel done */
u32 active:1; /* Channel active */
u32 major_elink:1; /* Enable channel-to-channel linking on major
* loop complete
*/
u32 e_sg:1; /* Enable scatter/gather processing */
u32 d_req:1; /* Disable request */
u32 int_half:1; /* Enable an interrupt when major counter is
* half complete
*/
u32 int_maj:1; /* Enable an interrupt when major iteration
* count completes
*/
u32 start:1; /* Channel start */
};
struct mpc_dma_desc {
struct dma_async_tx_descriptor desc;
struct mpc_dma_tcd *tcd;
dma_addr_t tcd_paddr;
int error;
struct list_head node;
int will_access_peripheral;
};
struct mpc_dma_chan {
struct dma_chan chan;
struct list_head free;
struct list_head prepared;
struct list_head queued;
struct list_head active;
struct list_head completed;
struct mpc_dma_tcd *tcd;
dma_addr_t tcd_paddr;
/* Settings for access to peripheral FIFO */
dma_addr_t src_per_paddr;
u32 src_tcd_nunits;
u8 swidth;
dma_addr_t dst_per_paddr;
u32 dst_tcd_nunits;
u8 dwidth;
/* Lock for this structure */
spinlock_t lock;
};
struct mpc_dma {
struct dma_device dma;
struct tasklet_struct tasklet;
struct mpc_dma_chan channels[MPC_DMA_CHANNELS];
struct mpc_dma_regs __iomem *regs;
struct mpc_dma_tcd __iomem *tcd;
int irq;
int irq2;
uint error_status;
int is_mpc8308;
/* Lock for error_status field in this structure */
spinlock_t error_status_lock;
};
#define DRV_NAME "mpc512x_dma"
/* Convert struct dma_chan to struct mpc_dma_chan */
static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c)
{
return container_of(c, struct mpc_dma_chan, chan);
}
/* Convert struct dma_chan to struct mpc_dma */
static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c)
{
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c);
return container_of(mchan, struct mpc_dma, channels[c->chan_id]);
}
/*
* Execute all queued DMA descriptors.
*
* Following requirements must be met while calling mpc_dma_execute():
* a) mchan->lock is acquired,
* b) mchan->active list is empty,
* c) mchan->queued list contains at least one entry.
*/
static void mpc_dma_execute(struct mpc_dma_chan *mchan)
{
struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
struct mpc_dma_desc *first = NULL;
struct mpc_dma_desc *prev = NULL;
struct mpc_dma_desc *mdesc;
int cid = mchan->chan.chan_id;
while (!list_empty(&mchan->queued)) {
mdesc = list_first_entry(&mchan->queued,
struct mpc_dma_desc, node);
/*
* Grab either several mem-to-mem transfer descriptors
* or one peripheral transfer descriptor,
* don't mix mem-to-mem and peripheral transfer descriptors
* within the same 'active' list.
*/
if (mdesc->will_access_peripheral) {
if (list_empty(&mchan->active))
list_move_tail(&mdesc->node, &mchan->active);
break;
} else {
list_move_tail(&mdesc->node, &mchan->active);
}
}
/* Chain descriptors into one transaction */
list_for_each_entry(mdesc, &mchan->active, node) {
if (!first)
first = mdesc;
if (!prev) {
prev = mdesc;
continue;
}
prev->tcd->dlast_sga = mdesc->tcd_paddr;
prev->tcd->e_sg = 1;
mdesc->tcd->start = 1;
prev = mdesc;
}
prev->tcd->int_maj = 1;
/* Send first descriptor in chain into hardware */
memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd));
if (first != prev)
mdma->tcd[cid].e_sg = 1;
if (mdma->is_mpc8308) {
/* MPC8308, no request lines, software initiated start */
out_8(&mdma->regs->dmassrt, cid);
} else if (first->will_access_peripheral) {
/* Peripherals involved, start by external request signal */
out_8(&mdma->regs->dmaserq, cid);
} else {
/* Memory to memory transfer, software initiated start */
out_8(&mdma->regs->dmassrt, cid);
}
}
/* Handle interrupt on one half of DMA controller (32 channels) */
static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off)
{
struct mpc_dma_chan *mchan;
struct mpc_dma_desc *mdesc;
u32 status = is | es;
int ch;
while ((ch = fls(status) - 1) >= 0) {
status &= ~(1 << ch);
mchan = &mdma->channels[ch + off];
spin_lock(&mchan->lock);
out_8(&mdma->regs->dmacint, ch + off);
out_8(&mdma->regs->dmacerr, ch + off);
/* Check error status */
if (es & (1 << ch))
list_for_each_entry(mdesc, &mchan->active, node)
mdesc->error = -EIO;
/* Execute queued descriptors */
list_splice_tail_init(&mchan->active, &mchan->completed);
if (!list_empty(&mchan->queued))
mpc_dma_execute(mchan);
spin_unlock(&mchan->lock);
}
}
/* Interrupt handler */
static irqreturn_t mpc_dma_irq(int irq, void *data)
{
struct mpc_dma *mdma = data;
uint es;
/* Save error status register */
es = in_be32(&mdma->regs->dmaes);
spin_lock(&mdma->error_status_lock);
if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0)
mdma->error_status = es;
spin_unlock(&mdma->error_status_lock);
/* Handle interrupt on each channel */
if (mdma->dma.chancnt > 32) {
mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth),
in_be32(&mdma->regs->dmaerrh), 32);
}
mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl),
in_be32(&mdma->regs->dmaerrl), 0);
/* Schedule tasklet */
tasklet_schedule(&mdma->tasklet);
return IRQ_HANDLED;
}
/* process completed descriptors */
static void mpc_dma_process_completed(struct mpc_dma *mdma)
{
dma_cookie_t last_cookie = 0;
struct mpc_dma_chan *mchan;
struct mpc_dma_desc *mdesc;
struct dma_async_tx_descriptor *desc;
unsigned long flags;
LIST_HEAD(list);
int i;
for (i = 0; i < mdma->dma.chancnt; i++) {
mchan = &mdma->channels[i];
/* Get all completed descriptors */
spin_lock_irqsave(&mchan->lock, flags);
if (!list_empty(&mchan->completed))
list_splice_tail_init(&mchan->completed, &list);
spin_unlock_irqrestore(&mchan->lock, flags);
if (list_empty(&list))
continue;
/* Execute callbacks and run dependencies */
list_for_each_entry(mdesc, &list, node) {
desc = &mdesc->desc;
dmaengine_desc_get_callback_invoke(desc, NULL);
last_cookie = desc->cookie;
dma_run_dependencies(desc);
}
/* Free descriptors */
spin_lock_irqsave(&mchan->lock, flags);
list_splice_tail_init(&list, &mchan->free);
mchan->chan.completed_cookie = last_cookie;
spin_unlock_irqrestore(&mchan->lock, flags);
}
}
/* DMA Tasklet */
static void mpc_dma_tasklet(struct tasklet_struct *t)
{
struct mpc_dma *mdma = from_tasklet(mdma, t, tasklet);
unsigned long flags;
uint es;
spin_lock_irqsave(&mdma->error_status_lock, flags);
es = mdma->error_status;
mdma->error_status = 0;
spin_unlock_irqrestore(&mdma->error_status_lock, flags);
/* Print nice error report */
if (es) {
dev_err(mdma->dma.dev,
"Hardware reported following error(s) on channel %u:\n",
MPC_DMA_DMAES_ERRCHN(es));
if (es & MPC_DMA_DMAES_GPE)
dev_err(mdma->dma.dev, "- Group Priority Error\n");
if (es & MPC_DMA_DMAES_CPE)
dev_err(mdma->dma.dev, "- Channel Priority Error\n");
if (es & MPC_DMA_DMAES_SAE)
dev_err(mdma->dma.dev, "- Source Address Error\n");
if (es & MPC_DMA_DMAES_SOE)
dev_err(mdma->dma.dev, "- Source Offset Configuration Error\n");
if (es & MPC_DMA_DMAES_DAE)
dev_err(mdma->dma.dev, "- Destination Address Error\n");
if (es & MPC_DMA_DMAES_DOE)
dev_err(mdma->dma.dev, "- Destination Offset Configuration Error\n");
if (es & MPC_DMA_DMAES_NCE)
dev_err(mdma->dma.dev, "- NBytes/Citter Configuration Error\n");
if (es & MPC_DMA_DMAES_SGE)
dev_err(mdma->dma.dev, "- Scatter/Gather Configuration Error\n");
if (es & MPC_DMA_DMAES_SBE)
dev_err(mdma->dma.dev, "- Source Bus Error\n");
if (es & MPC_DMA_DMAES_DBE)
dev_err(mdma->dma.dev, "- Destination Bus Error\n");
}
mpc_dma_process_completed(mdma);
}
/* Submit descriptor to hardware */
static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
{
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan);
struct mpc_dma_desc *mdesc;
unsigned long flags;
dma_cookie_t cookie;
mdesc = container_of(txd, struct mpc_dma_desc, desc);
spin_lock_irqsave(&mchan->lock, flags);
/* Move descriptor to queue */
list_move_tail(&mdesc->node, &mchan->queued);
/* If channel is idle, execute all queued descriptors */
if (list_empty(&mchan->active))
mpc_dma_execute(mchan);
/* Update cookie */
cookie = dma_cookie_assign(txd);
spin_unlock_irqrestore(&mchan->lock, flags);
return cookie;
}
/* Alloc channel resources */
static int mpc_dma_alloc_chan_resources(struct dma_chan *chan)
{
struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma_desc *mdesc;
struct mpc_dma_tcd *tcd;
dma_addr_t tcd_paddr;
unsigned long flags;
LIST_HEAD(descs);
int i;
/* Alloc DMA memory for Transfer Control Descriptors */
tcd = dma_alloc_coherent(mdma->dma.dev,
MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
&tcd_paddr, GFP_KERNEL);
if (!tcd)
return -ENOMEM;
/* Alloc descriptors for this channel */
for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) {
mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL);
if (!mdesc) {
dev_notice(mdma->dma.dev,
"Memory allocation error. Allocated only %u descriptors\n", i);
break;
}
dma_async_tx_descriptor_init(&mdesc->desc, chan);
mdesc->desc.flags = DMA_CTRL_ACK;
mdesc->desc.tx_submit = mpc_dma_tx_submit;
mdesc->tcd = &tcd[i];
mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd));
list_add_tail(&mdesc->node, &descs);
}
/* Return error only if no descriptors were allocated */
if (i == 0) {
dma_free_coherent(mdma->dma.dev,
MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
tcd, tcd_paddr);
return -ENOMEM;
}
spin_lock_irqsave(&mchan->lock, flags);
mchan->tcd = tcd;
mchan->tcd_paddr = tcd_paddr;
list_splice_tail_init(&descs, &mchan->free);
spin_unlock_irqrestore(&mchan->lock, flags);
/* Enable Error Interrupt */
out_8(&mdma->regs->dmaseei, chan->chan_id);
return 0;
}
/* Free channel resources */
static void mpc_dma_free_chan_resources(struct dma_chan *chan)
{
struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma_desc *mdesc, *tmp;
struct mpc_dma_tcd *tcd;
dma_addr_t tcd_paddr;
unsigned long flags;
LIST_HEAD(descs);
spin_lock_irqsave(&mchan->lock, flags);
/* Channel must be idle */
BUG_ON(!list_empty(&mchan->prepared));
BUG_ON(!list_empty(&mchan->queued));
BUG_ON(!list_empty(&mchan->active));
BUG_ON(!list_empty(&mchan->completed));
/* Move data */
list_splice_tail_init(&mchan->free, &descs);
tcd = mchan->tcd;
tcd_paddr = mchan->tcd_paddr;
spin_unlock_irqrestore(&mchan->lock, flags);
/* Free DMA memory used by descriptors */
dma_free_coherent(mdma->dma.dev,
MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
tcd, tcd_paddr);
/* Free descriptors */
list_for_each_entry_safe(mdesc, tmp, &descs, node)
kfree(mdesc);
/* Disable Error Interrupt */
out_8(&mdma->regs->dmaceei, chan->chan_id);
}
/* Send all pending descriptor to hardware */
static void mpc_dma_issue_pending(struct dma_chan *chan)
{
/*
* We are posting descriptors to the hardware as soon as
* they are ready, so this function does nothing.
*/
}
/* Check request completion status */
static enum dma_status
mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
return dma_cookie_status(chan, cookie, txstate);
}
/* Prepare descriptor for memory to memory copy */
static struct dma_async_tx_descriptor *
mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
size_t len, unsigned long flags)
{
struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma_desc *mdesc = NULL;
struct mpc_dma_tcd *tcd;
unsigned long iflags;
/* Get free descriptor */
spin_lock_irqsave(&mchan->lock, iflags);
if (!list_empty(&mchan->free)) {
mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
node);
list_del(&mdesc->node);
}
spin_unlock_irqrestore(&mchan->lock, iflags);
if (!mdesc) {
/* try to free completed descriptors */
mpc_dma_process_completed(mdma);
return NULL;
}
mdesc->error = 0;
mdesc->will_access_peripheral = 0;
tcd = mdesc->tcd;
/* Prepare Transfer Control Descriptor for this transaction */
memset(tcd, 0, sizeof(struct mpc_dma_tcd));
if (IS_ALIGNED(src | dst | len, 32)) {
tcd->ssize = MPC_DMA_TSIZE_32;
tcd->dsize = MPC_DMA_TSIZE_32;
tcd->soff = 32;
tcd->doff = 32;
} else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) {
/* MPC8308 doesn't support 16 byte transfers */
tcd->ssize = MPC_DMA_TSIZE_16;
tcd->dsize = MPC_DMA_TSIZE_16;
tcd->soff = 16;
tcd->doff = 16;
} else if (IS_ALIGNED(src | dst | len, 4)) {
tcd->ssize = MPC_DMA_TSIZE_4;
tcd->dsize = MPC_DMA_TSIZE_4;
tcd->soff = 4;
tcd->doff = 4;
} else if (IS_ALIGNED(src | dst | len, 2)) {
tcd->ssize = MPC_DMA_TSIZE_2;
tcd->dsize = MPC_DMA_TSIZE_2;
tcd->soff = 2;
tcd->doff = 2;
} else {
tcd->ssize = MPC_DMA_TSIZE_1;
tcd->dsize = MPC_DMA_TSIZE_1;
tcd->soff = 1;
tcd->doff = 1;
}
tcd->saddr = src;
tcd->daddr = dst;
tcd->nbytes = len;
tcd->biter = 1;
tcd->citer = 1;
/* Place descriptor in prepared list */
spin_lock_irqsave(&mchan->lock, iflags);
list_add_tail(&mdesc->node, &mchan->prepared);
spin_unlock_irqrestore(&mchan->lock, iflags);
return &mdesc->desc;
}
inline u8 buswidth_to_dmatsize(u8 buswidth)
{
u8 res;
for (res = 0; buswidth > 1; buswidth /= 2)
res++;
return res;
}
static struct dma_async_tx_descriptor *
mpc_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma_desc *mdesc = NULL;
dma_addr_t per_paddr;
u32 tcd_nunits;
struct mpc_dma_tcd *tcd;
unsigned long iflags;
struct scatterlist *sg;
size_t len;
int iter, i;
/* Currently there is no proper support for scatter/gather */
if (sg_len != 1)
return NULL;
if (!is_slave_direction(direction))
return NULL;
for_each_sg(sgl, sg, sg_len, i) {
spin_lock_irqsave(&mchan->lock, iflags);
mdesc = list_first_entry(&mchan->free,
struct mpc_dma_desc, node);
if (!mdesc) {
spin_unlock_irqrestore(&mchan->lock, iflags);
/* Try to free completed descriptors */
mpc_dma_process_completed(mdma);
return NULL;
}
list_del(&mdesc->node);
if (direction == DMA_DEV_TO_MEM) {
per_paddr = mchan->src_per_paddr;
tcd_nunits = mchan->src_tcd_nunits;
} else {
per_paddr = mchan->dst_per_paddr;
tcd_nunits = mchan->dst_tcd_nunits;
}
spin_unlock_irqrestore(&mchan->lock, iflags);
if (per_paddr == 0 || tcd_nunits == 0)
goto err_prep;
mdesc->error = 0;
mdesc->will_access_peripheral = 1;
/* Prepare Transfer Control Descriptor for this transaction */
tcd = mdesc->tcd;
memset(tcd, 0, sizeof(struct mpc_dma_tcd));
if (direction == DMA_DEV_TO_MEM) {
tcd->saddr = per_paddr;
tcd->daddr = sg_dma_address(sg);
if (!IS_ALIGNED(sg_dma_address(sg), mchan->dwidth))
goto err_prep;
tcd->soff = 0;
tcd->doff = mchan->dwidth;
} else {
tcd->saddr = sg_dma_address(sg);
tcd->daddr = per_paddr;
if (!IS_ALIGNED(sg_dma_address(sg), mchan->swidth))
goto err_prep;
tcd->soff = mchan->swidth;
tcd->doff = 0;
}
tcd->ssize = buswidth_to_dmatsize(mchan->swidth);
tcd->dsize = buswidth_to_dmatsize(mchan->dwidth);
if (mdma->is_mpc8308) {
tcd->nbytes = sg_dma_len(sg);
if (!IS_ALIGNED(tcd->nbytes, mchan->swidth))
goto err_prep;
/* No major loops for MPC8303 */
tcd->biter = 1;
tcd->citer = 1;
} else {
len = sg_dma_len(sg);
tcd->nbytes = tcd_nunits * tcd->ssize;
if (!IS_ALIGNED(len, tcd->nbytes))
goto err_prep;
iter = len / tcd->nbytes;
if (iter >= 1 << 15) {
/* len is too big */
goto err_prep;
}
/* citer_linkch contains the high bits of iter */
tcd->biter = iter & 0x1ff;
tcd->biter_linkch = iter >> 9;
tcd->citer = tcd->biter;
tcd->citer_linkch = tcd->biter_linkch;
}
tcd->e_sg = 0;
tcd->d_req = 1;
/* Place descriptor in prepared list */
spin_lock_irqsave(&mchan->lock, iflags);
list_add_tail(&mdesc->node, &mchan->prepared);
spin_unlock_irqrestore(&mchan->lock, iflags);
}
return &mdesc->desc;
err_prep:
/* Put the descriptor back */
spin_lock_irqsave(&mchan->lock, iflags);
list_add_tail(&mdesc->node, &mchan->free);
spin_unlock_irqrestore(&mchan->lock, iflags);
return NULL;
}
inline bool is_buswidth_valid(u8 buswidth, bool is_mpc8308)
{
switch (buswidth) {
case 16:
if (is_mpc8308)
return false;
break;
case 1:
case 2:
case 4:
case 32:
break;
default:
return false;
}
return true;
}
static int mpc_dma_device_config(struct dma_chan *chan,
struct dma_slave_config *cfg)
{
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
unsigned long flags;
/*
* Software constraints:
* - only transfers between a peripheral device and memory are
* supported
* - transfer chunk sizes of 1, 2, 4, 16 (for MPC512x), and 32 bytes
* are supported, and, consequently, source addresses and
* destination addresses; must be aligned accordingly; furthermore,
* for MPC512x SoCs, the transfer size must be aligned on (chunk
* size * maxburst)
* - during the transfer, the RAM address is incremented by the size
* of transfer chunk
* - the peripheral port's address is constant during the transfer.
*/
if (!IS_ALIGNED(cfg->src_addr, cfg->src_addr_width) ||
!IS_ALIGNED(cfg->dst_addr, cfg->dst_addr_width)) {
return -EINVAL;
}
if (!is_buswidth_valid(cfg->src_addr_width, mdma->is_mpc8308) ||
!is_buswidth_valid(cfg->dst_addr_width, mdma->is_mpc8308))
return -EINVAL;
spin_lock_irqsave(&mchan->lock, flags);
mchan->src_per_paddr = cfg->src_addr;
mchan->src_tcd_nunits = cfg->src_maxburst;
mchan->swidth = cfg->src_addr_width;
mchan->dst_per_paddr = cfg->dst_addr;
mchan->dst_tcd_nunits = cfg->dst_maxburst;
mchan->dwidth = cfg->dst_addr_width;
/* Apply defaults */
if (mchan->src_tcd_nunits == 0)
mchan->src_tcd_nunits = 1;
if (mchan->dst_tcd_nunits == 0)
mchan->dst_tcd_nunits = 1;
spin_unlock_irqrestore(&mchan->lock, flags);
return 0;
}
static int mpc_dma_device_terminate_all(struct dma_chan *chan)
{
struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
unsigned long flags;
/* Disable channel requests */
spin_lock_irqsave(&mchan->lock, flags);
out_8(&mdma->regs->dmacerq, chan->chan_id);
list_splice_tail_init(&mchan->prepared, &mchan->free);
list_splice_tail_init(&mchan->queued, &mchan->free);
list_splice_tail_init(&mchan->active, &mchan->free);
spin_unlock_irqrestore(&mchan->lock, flags);
return 0;
}
static int mpc_dma_probe(struct platform_device *op)
{
struct device_node *dn = op->dev.of_node;
struct device *dev = &op->dev;
struct dma_device *dma;
struct mpc_dma *mdma;
struct mpc_dma_chan *mchan;
struct resource res;
ulong regs_start, regs_size;
int retval, i;
u8 chancnt;
mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL);
if (!mdma) {
retval = -ENOMEM;
goto err;
}
mdma->irq = irq_of_parse_and_map(dn, 0);
if (!mdma->irq) {
dev_err(dev, "Error mapping IRQ!\n");
retval = -EINVAL;
goto err;
}
if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) {
mdma->is_mpc8308 = 1;
mdma->irq2 = irq_of_parse_and_map(dn, 1);
if (!mdma->irq2) {
dev_err(dev, "Error mapping IRQ!\n");
retval = -EINVAL;
goto err_dispose1;
}
}
retval = of_address_to_resource(dn, 0, &res);
if (retval) {
dev_err(dev, "Error parsing memory region!\n");
goto err_dispose2;
}
regs_start = res.start;
regs_size = resource_size(&res);
if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) {
dev_err(dev, "Error requesting memory region!\n");
retval = -EBUSY;
goto err_dispose2;
}
mdma->regs = devm_ioremap(dev, regs_start, regs_size);
if (!mdma->regs) {
dev_err(dev, "Error mapping memory region!\n");
retval = -ENOMEM;
goto err_dispose2;
}
mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs)
+ MPC_DMA_TCD_OFFSET);
retval = request_irq(mdma->irq, &mpc_dma_irq, 0, DRV_NAME, mdma);
if (retval) {
dev_err(dev, "Error requesting IRQ!\n");
retval = -EINVAL;
goto err_dispose2;
}
if (mdma->is_mpc8308) {
retval = request_irq(mdma->irq2, &mpc_dma_irq, 0,
DRV_NAME, mdma);
if (retval) {
dev_err(dev, "Error requesting IRQ2!\n");
retval = -EINVAL;
goto err_free1;
}
}
spin_lock_init(&mdma->error_status_lock);
dma = &mdma->dma;
dma->dev = dev;
dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
dma->device_free_chan_resources = mpc_dma_free_chan_resources;
dma->device_issue_pending = mpc_dma_issue_pending;
dma->device_tx_status = mpc_dma_tx_status;
dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
dma->device_prep_slave_sg = mpc_dma_prep_slave_sg;
dma->device_config = mpc_dma_device_config;
dma->device_terminate_all = mpc_dma_device_terminate_all;
INIT_LIST_HEAD(&dma->channels);
dma_cap_set(DMA_MEMCPY, dma->cap_mask);
dma_cap_set(DMA_SLAVE, dma->cap_mask);
if (mdma->is_mpc8308)
chancnt = MPC8308_DMACHAN_MAX;
else
chancnt = MPC512x_DMACHAN_MAX;
for (i = 0; i < chancnt; i++) {
mchan = &mdma->channels[i];
mchan->chan.device = dma;
dma_cookie_init(&mchan->chan);
INIT_LIST_HEAD(&mchan->free);
INIT_LIST_HEAD(&mchan->prepared);
INIT_LIST_HEAD(&mchan->queued);
INIT_LIST_HEAD(&mchan->active);
INIT_LIST_HEAD(&mchan->completed);
spin_lock_init(&mchan->lock);
list_add_tail(&mchan->chan.device_node, &dma->channels);
}
tasklet_setup(&mdma->tasklet, mpc_dma_tasklet);
/*
* Configure DMA Engine:
* - Dynamic clock,
* - Round-robin group arbitration,
* - Round-robin channel arbitration.
*/
if (mdma->is_mpc8308) {
/* MPC8308 has 16 channels and lacks some registers */
out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
/* enable snooping */
out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
/* Disable error interrupts */
out_be32(&mdma->regs->dmaeeil, 0);
/* Clear interrupts status */
out_be32(&mdma->regs->dmaintl, 0xFFFF);
out_be32(&mdma->regs->dmaerrl, 0xFFFF);
} else {
out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
MPC_DMA_DMACR_ERGA |
MPC_DMA_DMACR_ERCA);
/* Disable hardware DMA requests */
out_be32(&mdma->regs->dmaerqh, 0);
out_be32(&mdma->regs->dmaerql, 0);
/* Disable error interrupts */
out_be32(&mdma->regs->dmaeeih, 0);
out_be32(&mdma->regs->dmaeeil, 0);
/* Clear interrupts status */
out_be32(&mdma->regs->dmainth, 0xFFFFFFFF);
out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF);
out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF);
out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF);
/* Route interrupts to IPIC */
out_be32(&mdma->regs->dmaihsa, 0);
out_be32(&mdma->regs->dmailsa, 0);
}
/* Register DMA engine */
dev_set_drvdata(dev, mdma);
retval = dma_async_device_register(dma);
if (retval)
goto err_free2;
/* Register with OF helpers for DMA lookups (nonfatal) */
if (dev->of_node) {
retval = of_dma_controller_register(dev->of_node,
of_dma_xlate_by_chan_id, mdma);
if (retval)
dev_warn(dev, "Could not register for OF lookup\n");
}
return 0;
err_free2:
if (mdma->is_mpc8308)
free_irq(mdma->irq2, mdma);
err_free1:
free_irq(mdma->irq, mdma);
err_dispose2:
if (mdma->is_mpc8308)
irq_dispose_mapping(mdma->irq2);
err_dispose1:
irq_dispose_mapping(mdma->irq);
err:
return retval;
}
static int mpc_dma_remove(struct platform_device *op)
{
struct device *dev = &op->dev;
struct mpc_dma *mdma = dev_get_drvdata(dev);
if (dev->of_node)
of_dma_controller_free(dev->of_node);
dma_async_device_unregister(&mdma->dma);
if (mdma->is_mpc8308) {
free_irq(mdma->irq2, mdma);
irq_dispose_mapping(mdma->irq2);
}
free_irq(mdma->irq, mdma);
irq_dispose_mapping(mdma->irq);
tasklet_kill(&mdma->tasklet);
return 0;
}
static const struct of_device_id mpc_dma_match[] = {
{ .compatible = "fsl,mpc5121-dma", },
{ .compatible = "fsl,mpc8308-dma", },
{},
};
MODULE_DEVICE_TABLE(of, mpc_dma_match);
static struct platform_driver mpc_dma_driver = {
.probe = mpc_dma_probe,
.remove = mpc_dma_remove,
.driver = {
.name = DRV_NAME,
.of_match_table = mpc_dma_match,
},
};
module_platform_driver(mpc_dma_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>");