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linux/drivers/dma/mpc512x_dma.c
Uwe Kleine-König 80d0159bbe dmaengine: mpc512x_dma: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919133207.1400430-29-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2023-09-28 13:10:51 +05:30

1124 lines
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// 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 void 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);
}
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_new = 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>");
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