linux/drivers/dma/sh/rcar-dmac.c
Uwe Kleine-König 8ca342994a dmaengine: sh: rcar-dmac: 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/20230919133207.1400430-40-u.kleine-koenig@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2023-09-28 13:10:54 +05:30

2051 lines
55 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Renesas R-Car Gen2/Gen3 DMA Controller Driver
*
* Copyright (C) 2014-2019 Renesas Electronics Inc.
*
* Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
*/
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "../dmaengine.h"
/*
* struct rcar_dmac_xfer_chunk - Descriptor for a hardware transfer
* @node: entry in the parent's chunks list
* @src_addr: device source address
* @dst_addr: device destination address
* @size: transfer size in bytes
*/
struct rcar_dmac_xfer_chunk {
struct list_head node;
dma_addr_t src_addr;
dma_addr_t dst_addr;
u32 size;
};
/*
* struct rcar_dmac_hw_desc - Hardware descriptor for a transfer chunk
* @sar: value of the SAR register (source address)
* @dar: value of the DAR register (destination address)
* @tcr: value of the TCR register (transfer count)
*/
struct rcar_dmac_hw_desc {
u32 sar;
u32 dar;
u32 tcr;
u32 reserved;
} __attribute__((__packed__));
/*
* struct rcar_dmac_desc - R-Car Gen2 DMA Transfer Descriptor
* @async_tx: base DMA asynchronous transaction descriptor
* @direction: direction of the DMA transfer
* @xfer_shift: log2 of the transfer size
* @chcr: value of the channel configuration register for this transfer
* @node: entry in the channel's descriptors lists
* @chunks: list of transfer chunks for this transfer
* @running: the transfer chunk being currently processed
* @nchunks: number of transfer chunks for this transfer
* @hwdescs.use: whether the transfer descriptor uses hardware descriptors
* @hwdescs.mem: hardware descriptors memory for the transfer
* @hwdescs.dma: device address of the hardware descriptors memory
* @hwdescs.size: size of the hardware descriptors in bytes
* @size: transfer size in bytes
* @cyclic: when set indicates that the DMA transfer is cyclic
*/
struct rcar_dmac_desc {
struct dma_async_tx_descriptor async_tx;
enum dma_transfer_direction direction;
unsigned int xfer_shift;
u32 chcr;
struct list_head node;
struct list_head chunks;
struct rcar_dmac_xfer_chunk *running;
unsigned int nchunks;
struct {
bool use;
struct rcar_dmac_hw_desc *mem;
dma_addr_t dma;
size_t size;
} hwdescs;
unsigned int size;
bool cyclic;
};
#define to_rcar_dmac_desc(d) container_of(d, struct rcar_dmac_desc, async_tx)
/*
* struct rcar_dmac_desc_page - One page worth of descriptors
* @node: entry in the channel's pages list
* @descs: array of DMA descriptors
* @chunks: array of transfer chunk descriptors
*/
struct rcar_dmac_desc_page {
struct list_head node;
union {
DECLARE_FLEX_ARRAY(struct rcar_dmac_desc, descs);
DECLARE_FLEX_ARRAY(struct rcar_dmac_xfer_chunk, chunks);
};
};
#define RCAR_DMAC_DESCS_PER_PAGE \
((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, descs)) / \
sizeof(struct rcar_dmac_desc))
#define RCAR_DMAC_XFER_CHUNKS_PER_PAGE \
((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, chunks)) / \
sizeof(struct rcar_dmac_xfer_chunk))
/*
* struct rcar_dmac_chan_slave - Slave configuration
* @slave_addr: slave memory address
* @xfer_size: size (in bytes) of hardware transfers
*/
struct rcar_dmac_chan_slave {
phys_addr_t slave_addr;
unsigned int xfer_size;
};
/*
* struct rcar_dmac_chan_map - Map of slave device phys to dma address
* @addr: slave dma address
* @dir: direction of mapping
* @slave: slave configuration that is mapped
*/
struct rcar_dmac_chan_map {
dma_addr_t addr;
enum dma_data_direction dir;
struct rcar_dmac_chan_slave slave;
};
/*
* struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel
* @chan: base DMA channel object
* @iomem: channel I/O memory base
* @index: index of this channel in the controller
* @irq: channel IRQ
* @src: slave memory address and size on the source side
* @dst: slave memory address and size on the destination side
* @mid_rid: hardware MID/RID for the DMA client using this channel
* @lock: protects the channel CHCR register and the desc members
* @desc.free: list of free descriptors
* @desc.pending: list of pending descriptors (submitted with tx_submit)
* @desc.active: list of active descriptors (activated with issue_pending)
* @desc.done: list of completed descriptors
* @desc.wait: list of descriptors waiting for an ack
* @desc.running: the descriptor being processed (a member of the active list)
* @desc.chunks_free: list of free transfer chunk descriptors
* @desc.pages: list of pages used by allocated descriptors
*/
struct rcar_dmac_chan {
struct dma_chan chan;
void __iomem *iomem;
unsigned int index;
int irq;
struct rcar_dmac_chan_slave src;
struct rcar_dmac_chan_slave dst;
struct rcar_dmac_chan_map map;
int mid_rid;
spinlock_t lock;
struct {
struct list_head free;
struct list_head pending;
struct list_head active;
struct list_head done;
struct list_head wait;
struct rcar_dmac_desc *running;
struct list_head chunks_free;
struct list_head pages;
} desc;
};
#define to_rcar_dmac_chan(c) container_of(c, struct rcar_dmac_chan, chan)
/*
* struct rcar_dmac - R-Car Gen2 DMA Controller
* @engine: base DMA engine object
* @dev: the hardware device
* @dmac_base: remapped base register block
* @chan_base: remapped channel register block (optional)
* @n_channels: number of available channels
* @channels: array of DMAC channels
* @channels_mask: bitfield of which DMA channels are managed by this driver
* @modules: bitmask of client modules in use
*/
struct rcar_dmac {
struct dma_device engine;
struct device *dev;
void __iomem *dmac_base;
void __iomem *chan_base;
unsigned int n_channels;
struct rcar_dmac_chan *channels;
u32 channels_mask;
DECLARE_BITMAP(modules, 256);
};
#define to_rcar_dmac(d) container_of(d, struct rcar_dmac, engine)
#define for_each_rcar_dmac_chan(i, dmac, chan) \
for (i = 0, chan = &(dmac)->channels[0]; i < (dmac)->n_channels; i++, chan++) \
if (!((dmac)->channels_mask & BIT(i))) continue; else
/*
* struct rcar_dmac_of_data - This driver's OF data
* @chan_offset_base: DMAC channels base offset
* @chan_offset_stride: DMAC channels offset stride
*/
struct rcar_dmac_of_data {
u32 chan_offset_base;
u32 chan_offset_stride;
};
/* -----------------------------------------------------------------------------
* Registers
*/
#define RCAR_DMAISTA 0x0020
#define RCAR_DMASEC 0x0030
#define RCAR_DMAOR 0x0060
#define RCAR_DMAOR_PRI_FIXED (0 << 8)
#define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8)
#define RCAR_DMAOR_AE (1 << 2)
#define RCAR_DMAOR_DME (1 << 0)
#define RCAR_DMACHCLR 0x0080 /* Not on R-Car Gen4 */
#define RCAR_DMADPSEC 0x00a0
#define RCAR_DMASAR 0x0000
#define RCAR_DMADAR 0x0004
#define RCAR_DMATCR 0x0008
#define RCAR_DMATCR_MASK 0x00ffffff
#define RCAR_DMATSR 0x0028
#define RCAR_DMACHCR 0x000c
#define RCAR_DMACHCR_CAE (1 << 31)
#define RCAR_DMACHCR_CAIE (1 << 30)
#define RCAR_DMACHCR_DPM_DISABLED (0 << 28)
#define RCAR_DMACHCR_DPM_ENABLED (1 << 28)
#define RCAR_DMACHCR_DPM_REPEAT (2 << 28)
#define RCAR_DMACHCR_DPM_INFINITE (3 << 28)
#define RCAR_DMACHCR_RPT_SAR (1 << 27)
#define RCAR_DMACHCR_RPT_DAR (1 << 26)
#define RCAR_DMACHCR_RPT_TCR (1 << 25)
#define RCAR_DMACHCR_DPB (1 << 22)
#define RCAR_DMACHCR_DSE (1 << 19)
#define RCAR_DMACHCR_DSIE (1 << 18)
#define RCAR_DMACHCR_TS_1B ((0 << 20) | (0 << 3))
#define RCAR_DMACHCR_TS_2B ((0 << 20) | (1 << 3))
#define RCAR_DMACHCR_TS_4B ((0 << 20) | (2 << 3))
#define RCAR_DMACHCR_TS_16B ((0 << 20) | (3 << 3))
#define RCAR_DMACHCR_TS_32B ((1 << 20) | (0 << 3))
#define RCAR_DMACHCR_TS_64B ((1 << 20) | (1 << 3))
#define RCAR_DMACHCR_TS_8B ((1 << 20) | (3 << 3))
#define RCAR_DMACHCR_DM_FIXED (0 << 14)
#define RCAR_DMACHCR_DM_INC (1 << 14)
#define RCAR_DMACHCR_DM_DEC (2 << 14)
#define RCAR_DMACHCR_SM_FIXED (0 << 12)
#define RCAR_DMACHCR_SM_INC (1 << 12)
#define RCAR_DMACHCR_SM_DEC (2 << 12)
#define RCAR_DMACHCR_RS_AUTO (4 << 8)
#define RCAR_DMACHCR_RS_DMARS (8 << 8)
#define RCAR_DMACHCR_IE (1 << 2)
#define RCAR_DMACHCR_TE (1 << 1)
#define RCAR_DMACHCR_DE (1 << 0)
#define RCAR_DMATCRB 0x0018
#define RCAR_DMATSRB 0x0038
#define RCAR_DMACHCRB 0x001c
#define RCAR_DMACHCRB_DCNT(n) ((n) << 24)
#define RCAR_DMACHCRB_DPTR_MASK (0xff << 16)
#define RCAR_DMACHCRB_DPTR_SHIFT 16
#define RCAR_DMACHCRB_DRST (1 << 15)
#define RCAR_DMACHCRB_DTS (1 << 8)
#define RCAR_DMACHCRB_SLM_NORMAL (0 << 4)
#define RCAR_DMACHCRB_SLM_CLK(n) ((8 | (n)) << 4)
#define RCAR_DMACHCRB_PRI(n) ((n) << 0)
#define RCAR_DMARS 0x0040
#define RCAR_DMABUFCR 0x0048
#define RCAR_DMABUFCR_MBU(n) ((n) << 16)
#define RCAR_DMABUFCR_ULB(n) ((n) << 0)
#define RCAR_DMADPBASE 0x0050
#define RCAR_DMADPBASE_MASK 0xfffffff0
#define RCAR_DMADPBASE_SEL (1 << 0)
#define RCAR_DMADPCR 0x0054
#define RCAR_DMADPCR_DIPT(n) ((n) << 24)
#define RCAR_DMAFIXSAR 0x0010
#define RCAR_DMAFIXDAR 0x0014
#define RCAR_DMAFIXDPBASE 0x0060
/* For R-Car Gen4 */
#define RCAR_GEN4_DMACHCLR 0x0100
/* Hardcode the MEMCPY transfer size to 4 bytes. */
#define RCAR_DMAC_MEMCPY_XFER_SIZE 4
/* -----------------------------------------------------------------------------
* Device access
*/
static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data)
{
if (reg == RCAR_DMAOR)
writew(data, dmac->dmac_base + reg);
else
writel(data, dmac->dmac_base + reg);
}
static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg)
{
if (reg == RCAR_DMAOR)
return readw(dmac->dmac_base + reg);
else
return readl(dmac->dmac_base + reg);
}
static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg)
{
if (reg == RCAR_DMARS)
return readw(chan->iomem + reg);
else
return readl(chan->iomem + reg);
}
static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data)
{
if (reg == RCAR_DMARS)
writew(data, chan->iomem + reg);
else
writel(data, chan->iomem + reg);
}
static void rcar_dmac_chan_clear(struct rcar_dmac *dmac,
struct rcar_dmac_chan *chan)
{
if (dmac->chan_base)
rcar_dmac_chan_write(chan, RCAR_GEN4_DMACHCLR, 1);
else
rcar_dmac_write(dmac, RCAR_DMACHCLR, BIT(chan->index));
}
static void rcar_dmac_chan_clear_all(struct rcar_dmac *dmac)
{
struct rcar_dmac_chan *chan;
unsigned int i;
if (dmac->chan_base) {
for_each_rcar_dmac_chan(i, dmac, chan)
rcar_dmac_chan_write(chan, RCAR_GEN4_DMACHCLR, 1);
} else {
rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask);
}
}
/* -----------------------------------------------------------------------------
* Initialization and configuration
*/
static bool rcar_dmac_chan_is_busy(struct rcar_dmac_chan *chan)
{
u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
return !!(chcr & (RCAR_DMACHCR_DE | RCAR_DMACHCR_TE));
}
static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc = chan->desc.running;
u32 chcr = desc->chcr;
WARN_ON_ONCE(rcar_dmac_chan_is_busy(chan));
if (chan->mid_rid >= 0)
rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid);
if (desc->hwdescs.use) {
struct rcar_dmac_xfer_chunk *chunk =
list_first_entry(&desc->chunks,
struct rcar_dmac_xfer_chunk, node);
dev_dbg(chan->chan.device->dev,
"chan%u: queue desc %p: %u@%pad\n",
chan->index, desc, desc->nchunks, &desc->hwdescs.dma);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR,
chunk->src_addr >> 32);
rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR,
chunk->dst_addr >> 32);
rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE,
desc->hwdescs.dma >> 32);
#endif
rcar_dmac_chan_write(chan, RCAR_DMADPBASE,
(desc->hwdescs.dma & 0xfffffff0) |
RCAR_DMADPBASE_SEL);
rcar_dmac_chan_write(chan, RCAR_DMACHCRB,
RCAR_DMACHCRB_DCNT(desc->nchunks - 1) |
RCAR_DMACHCRB_DRST);
/*
* Errata: When descriptor memory is accessed through an IOMMU
* the DMADAR register isn't initialized automatically from the
* first descriptor at beginning of transfer by the DMAC like it
* should. Initialize it manually with the destination address
* of the first chunk.
*/
rcar_dmac_chan_write(chan, RCAR_DMADAR,
chunk->dst_addr & 0xffffffff);
/*
* Program the descriptor stage interrupt to occur after the end
* of the first stage.
*/
rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(1));
chcr |= RCAR_DMACHCR_RPT_SAR | RCAR_DMACHCR_RPT_DAR
| RCAR_DMACHCR_RPT_TCR | RCAR_DMACHCR_DPB;
/*
* If the descriptor isn't cyclic enable normal descriptor mode
* and the transfer completion interrupt.
*/
if (!desc->cyclic)
chcr |= RCAR_DMACHCR_DPM_ENABLED | RCAR_DMACHCR_IE;
/*
* If the descriptor is cyclic and has a callback enable the
* descriptor stage interrupt in infinite repeat mode.
*/
else if (desc->async_tx.callback)
chcr |= RCAR_DMACHCR_DPM_INFINITE | RCAR_DMACHCR_DSIE;
/*
* Otherwise just select infinite repeat mode without any
* interrupt.
*/
else
chcr |= RCAR_DMACHCR_DPM_INFINITE;
} else {
struct rcar_dmac_xfer_chunk *chunk = desc->running;
dev_dbg(chan->chan.device->dev,
"chan%u: queue chunk %p: %u@%pad -> %pad\n",
chan->index, chunk, chunk->size, &chunk->src_addr,
&chunk->dst_addr);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR,
chunk->src_addr >> 32);
rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR,
chunk->dst_addr >> 32);
#endif
rcar_dmac_chan_write(chan, RCAR_DMASAR,
chunk->src_addr & 0xffffffff);
rcar_dmac_chan_write(chan, RCAR_DMADAR,
chunk->dst_addr & 0xffffffff);
rcar_dmac_chan_write(chan, RCAR_DMATCR,
chunk->size >> desc->xfer_shift);
chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE;
}
rcar_dmac_chan_write(chan, RCAR_DMACHCR,
chcr | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAIE);
}
static int rcar_dmac_init(struct rcar_dmac *dmac)
{
u16 dmaor;
/* Clear all channels and enable the DMAC globally. */
rcar_dmac_chan_clear_all(dmac);
rcar_dmac_write(dmac, RCAR_DMAOR,
RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME);
dmaor = rcar_dmac_read(dmac, RCAR_DMAOR);
if ((dmaor & (RCAR_DMAOR_AE | RCAR_DMAOR_DME)) != RCAR_DMAOR_DME) {
dev_warn(dmac->dev, "DMAOR initialization failed.\n");
return -EIO;
}
return 0;
}
/* -----------------------------------------------------------------------------
* Descriptors submission
*/
static dma_cookie_t rcar_dmac_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct rcar_dmac_chan *chan = to_rcar_dmac_chan(tx->chan);
struct rcar_dmac_desc *desc = to_rcar_dmac_desc(tx);
unsigned long flags;
dma_cookie_t cookie;
spin_lock_irqsave(&chan->lock, flags);
cookie = dma_cookie_assign(tx);
dev_dbg(chan->chan.device->dev, "chan%u: submit #%d@%p\n",
chan->index, tx->cookie, desc);
list_add_tail(&desc->node, &chan->desc.pending);
desc->running = list_first_entry(&desc->chunks,
struct rcar_dmac_xfer_chunk, node);
spin_unlock_irqrestore(&chan->lock, flags);
return cookie;
}
/* -----------------------------------------------------------------------------
* Descriptors allocation and free
*/
/*
* rcar_dmac_desc_alloc - Allocate a page worth of DMA descriptors
* @chan: the DMA channel
* @gfp: allocation flags
*/
static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp)
{
struct rcar_dmac_desc_page *page;
unsigned long flags;
LIST_HEAD(list);
unsigned int i;
page = (void *)get_zeroed_page(gfp);
if (!page)
return -ENOMEM;
for (i = 0; i < RCAR_DMAC_DESCS_PER_PAGE; ++i) {
struct rcar_dmac_desc *desc = &page->descs[i];
dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan);
desc->async_tx.tx_submit = rcar_dmac_tx_submit;
INIT_LIST_HEAD(&desc->chunks);
list_add_tail(&desc->node, &list);
}
spin_lock_irqsave(&chan->lock, flags);
list_splice_tail(&list, &chan->desc.free);
list_add_tail(&page->node, &chan->desc.pages);
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
/*
* rcar_dmac_desc_put - Release a DMA transfer descriptor
* @chan: the DMA channel
* @desc: the descriptor
*
* Put the descriptor and its transfer chunk descriptors back in the channel's
* free descriptors lists. The descriptor's chunks list will be reinitialized to
* an empty list as a result.
*
* The descriptor must have been removed from the channel's lists before calling
* this function.
*/
static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan,
struct rcar_dmac_desc *desc)
{
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free);
list_add(&desc->node, &chan->desc.free);
spin_unlock_irqrestore(&chan->lock, flags);
}
static void rcar_dmac_desc_recycle_acked(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(list);
/*
* We have to temporarily move all descriptors from the wait list to a
* local list as iterating over the wait list, even with
* list_for_each_entry_safe, isn't safe if we release the channel lock
* around the rcar_dmac_desc_put() call.
*/
spin_lock_irqsave(&chan->lock, flags);
list_splice_init(&chan->desc.wait, &list);
spin_unlock_irqrestore(&chan->lock, flags);
list_for_each_entry_safe(desc, _desc, &list, node) {
if (async_tx_test_ack(&desc->async_tx)) {
list_del(&desc->node);
rcar_dmac_desc_put(chan, desc);
}
}
if (list_empty(&list))
return;
/* Put the remaining descriptors back in the wait list. */
spin_lock_irqsave(&chan->lock, flags);
list_splice(&list, &chan->desc.wait);
spin_unlock_irqrestore(&chan->lock, flags);
}
/*
* rcar_dmac_desc_get - Allocate a descriptor for a DMA transfer
* @chan: the DMA channel
*
* Locking: This function must be called in a non-atomic context.
*
* Return: A pointer to the allocated descriptor or NULL if no descriptor can
* be allocated.
*/
static struct rcar_dmac_desc *rcar_dmac_desc_get(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc;
unsigned long flags;
int ret;
/* Recycle acked descriptors before attempting allocation. */
rcar_dmac_desc_recycle_acked(chan);
spin_lock_irqsave(&chan->lock, flags);
while (list_empty(&chan->desc.free)) {
/*
* No free descriptors, allocate a page worth of them and try
* again, as someone else could race us to get the newly
* allocated descriptors. If the allocation fails return an
* error.
*/
spin_unlock_irqrestore(&chan->lock, flags);
ret = rcar_dmac_desc_alloc(chan, GFP_NOWAIT);
if (ret < 0)
return NULL;
spin_lock_irqsave(&chan->lock, flags);
}
desc = list_first_entry(&chan->desc.free, struct rcar_dmac_desc, node);
list_del(&desc->node);
spin_unlock_irqrestore(&chan->lock, flags);
return desc;
}
/*
* rcar_dmac_xfer_chunk_alloc - Allocate a page worth of transfer chunks
* @chan: the DMA channel
* @gfp: allocation flags
*/
static int rcar_dmac_xfer_chunk_alloc(struct rcar_dmac_chan *chan, gfp_t gfp)
{
struct rcar_dmac_desc_page *page;
unsigned long flags;
LIST_HEAD(list);
unsigned int i;
page = (void *)get_zeroed_page(gfp);
if (!page)
return -ENOMEM;
for (i = 0; i < RCAR_DMAC_XFER_CHUNKS_PER_PAGE; ++i) {
struct rcar_dmac_xfer_chunk *chunk = &page->chunks[i];
list_add_tail(&chunk->node, &list);
}
spin_lock_irqsave(&chan->lock, flags);
list_splice_tail(&list, &chan->desc.chunks_free);
list_add_tail(&page->node, &chan->desc.pages);
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
/*
* rcar_dmac_xfer_chunk_get - Allocate a transfer chunk for a DMA transfer
* @chan: the DMA channel
*
* Locking: This function must be called in a non-atomic context.
*
* Return: A pointer to the allocated transfer chunk descriptor or NULL if no
* descriptor can be allocated.
*/
static struct rcar_dmac_xfer_chunk *
rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_xfer_chunk *chunk;
unsigned long flags;
int ret;
spin_lock_irqsave(&chan->lock, flags);
while (list_empty(&chan->desc.chunks_free)) {
/*
* No free descriptors, allocate a page worth of them and try
* again, as someone else could race us to get the newly
* allocated descriptors. If the allocation fails return an
* error.
*/
spin_unlock_irqrestore(&chan->lock, flags);
ret = rcar_dmac_xfer_chunk_alloc(chan, GFP_NOWAIT);
if (ret < 0)
return NULL;
spin_lock_irqsave(&chan->lock, flags);
}
chunk = list_first_entry(&chan->desc.chunks_free,
struct rcar_dmac_xfer_chunk, node);
list_del(&chunk->node);
spin_unlock_irqrestore(&chan->lock, flags);
return chunk;
}
static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan,
struct rcar_dmac_desc *desc, size_t size)
{
/*
* dma_alloc_coherent() allocates memory in page size increments. To
* avoid reallocating the hardware descriptors when the allocated size
* wouldn't change align the requested size to a multiple of the page
* size.
*/
size = PAGE_ALIGN(size);
if (desc->hwdescs.size == size)
return;
if (desc->hwdescs.mem) {
dma_free_coherent(chan->chan.device->dev, desc->hwdescs.size,
desc->hwdescs.mem, desc->hwdescs.dma);
desc->hwdescs.mem = NULL;
desc->hwdescs.size = 0;
}
if (!size)
return;
desc->hwdescs.mem = dma_alloc_coherent(chan->chan.device->dev, size,
&desc->hwdescs.dma, GFP_NOWAIT);
if (!desc->hwdescs.mem)
return;
desc->hwdescs.size = size;
}
static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan,
struct rcar_dmac_desc *desc)
{
struct rcar_dmac_xfer_chunk *chunk;
struct rcar_dmac_hw_desc *hwdesc;
rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc));
hwdesc = desc->hwdescs.mem;
if (!hwdesc)
return -ENOMEM;
list_for_each_entry(chunk, &desc->chunks, node) {
hwdesc->sar = chunk->src_addr;
hwdesc->dar = chunk->dst_addr;
hwdesc->tcr = chunk->size >> desc->xfer_shift;
hwdesc++;
}
return 0;
}
/* -----------------------------------------------------------------------------
* Stop and reset
*/
static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan)
{
u32 chcr;
unsigned int i;
/*
* Ensure that the setting of the DE bit is actually 0 after
* clearing it.
*/
for (i = 0; i < 1024; i++) {
chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
if (!(chcr & RCAR_DMACHCR_DE))
return;
udelay(1);
}
dev_err(chan->chan.device->dev, "CHCR DE check error\n");
}
static void rcar_dmac_clear_chcr_de(struct rcar_dmac_chan *chan)
{
u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
/* set DE=0 and flush remaining data */
rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE));
/* make sure all remaining data was flushed */
rcar_dmac_chcr_de_barrier(chan);
}
static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan)
{
u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE |
RCAR_DMACHCR_TE | RCAR_DMACHCR_DE |
RCAR_DMACHCR_CAE | RCAR_DMACHCR_CAIE);
rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr);
rcar_dmac_chcr_de_barrier(chan);
}
static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc, *_desc;
unsigned long flags;
LIST_HEAD(descs);
spin_lock_irqsave(&chan->lock, flags);
/* Move all non-free descriptors to the local lists. */
list_splice_init(&chan->desc.pending, &descs);
list_splice_init(&chan->desc.active, &descs);
list_splice_init(&chan->desc.done, &descs);
list_splice_init(&chan->desc.wait, &descs);
chan->desc.running = NULL;
spin_unlock_irqrestore(&chan->lock, flags);
list_for_each_entry_safe(desc, _desc, &descs, node) {
list_del(&desc->node);
rcar_dmac_desc_put(chan, desc);
}
}
static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac)
{
struct rcar_dmac_chan *chan;
unsigned int i;
/* Stop all channels. */
for_each_rcar_dmac_chan(i, dmac, chan) {
/* Stop and reinitialize the channel. */
spin_lock_irq(&chan->lock);
rcar_dmac_chan_halt(chan);
spin_unlock_irq(&chan->lock);
}
}
static int rcar_dmac_chan_pause(struct dma_chan *chan)
{
unsigned long flags;
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
spin_lock_irqsave(&rchan->lock, flags);
rcar_dmac_clear_chcr_de(rchan);
spin_unlock_irqrestore(&rchan->lock, flags);
return 0;
}
/* -----------------------------------------------------------------------------
* Descriptors preparation
*/
static void rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan,
struct rcar_dmac_desc *desc)
{
static const u32 chcr_ts[] = {
RCAR_DMACHCR_TS_1B, RCAR_DMACHCR_TS_2B,
RCAR_DMACHCR_TS_4B, RCAR_DMACHCR_TS_8B,
RCAR_DMACHCR_TS_16B, RCAR_DMACHCR_TS_32B,
RCAR_DMACHCR_TS_64B,
};
unsigned int xfer_size;
u32 chcr;
switch (desc->direction) {
case DMA_DEV_TO_MEM:
chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED
| RCAR_DMACHCR_RS_DMARS;
xfer_size = chan->src.xfer_size;
break;
case DMA_MEM_TO_DEV:
chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC
| RCAR_DMACHCR_RS_DMARS;
xfer_size = chan->dst.xfer_size;
break;
case DMA_MEM_TO_MEM:
default:
chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_INC
| RCAR_DMACHCR_RS_AUTO;
xfer_size = RCAR_DMAC_MEMCPY_XFER_SIZE;
break;
}
desc->xfer_shift = ilog2(xfer_size);
desc->chcr = chcr | chcr_ts[desc->xfer_shift];
}
/*
* rcar_dmac_chan_prep_sg - prepare transfer descriptors from an SG list
*
* Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
* converted to scatter-gather to guarantee consistent locking and a correct
* list manipulation. For slave DMA direction carries the usual meaning, and,
* logically, the SG list is RAM and the addr variable contains slave address,
* e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM
* and the SG list contains only one element and points at the source buffer.
*/
static struct dma_async_tx_descriptor *
rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, dma_addr_t dev_addr,
enum dma_transfer_direction dir, unsigned long dma_flags,
bool cyclic)
{
struct rcar_dmac_xfer_chunk *chunk;
struct rcar_dmac_desc *desc;
struct scatterlist *sg;
unsigned int nchunks = 0;
unsigned int max_chunk_size;
unsigned int full_size = 0;
bool cross_boundary = false;
unsigned int i;
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
u32 high_dev_addr;
u32 high_mem_addr;
#endif
desc = rcar_dmac_desc_get(chan);
if (!desc)
return NULL;
desc->async_tx.flags = dma_flags;
desc->async_tx.cookie = -EBUSY;
desc->cyclic = cyclic;
desc->direction = dir;
rcar_dmac_chan_configure_desc(chan, desc);
max_chunk_size = RCAR_DMATCR_MASK << desc->xfer_shift;
/*
* Allocate and fill the transfer chunk descriptors. We own the only
* reference to the DMA descriptor, there's no need for locking.
*/
for_each_sg(sgl, sg, sg_len, i) {
dma_addr_t mem_addr = sg_dma_address(sg);
unsigned int len = sg_dma_len(sg);
full_size += len;
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
if (i == 0) {
high_dev_addr = dev_addr >> 32;
high_mem_addr = mem_addr >> 32;
}
if ((dev_addr >> 32 != high_dev_addr) ||
(mem_addr >> 32 != high_mem_addr))
cross_boundary = true;
#endif
while (len) {
unsigned int size = min(len, max_chunk_size);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
/*
* Prevent individual transfers from crossing 4GB
* boundaries.
*/
if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) {
size = ALIGN(dev_addr, 1ULL << 32) - dev_addr;
cross_boundary = true;
}
if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) {
size = ALIGN(mem_addr, 1ULL << 32) - mem_addr;
cross_boundary = true;
}
#endif
chunk = rcar_dmac_xfer_chunk_get(chan);
if (!chunk) {
rcar_dmac_desc_put(chan, desc);
return NULL;
}
if (dir == DMA_DEV_TO_MEM) {
chunk->src_addr = dev_addr;
chunk->dst_addr = mem_addr;
} else {
chunk->src_addr = mem_addr;
chunk->dst_addr = dev_addr;
}
chunk->size = size;
dev_dbg(chan->chan.device->dev,
"chan%u: chunk %p/%p sgl %u@%p, %u/%u %pad -> %pad\n",
chan->index, chunk, desc, i, sg, size, len,
&chunk->src_addr, &chunk->dst_addr);
mem_addr += size;
if (dir == DMA_MEM_TO_MEM)
dev_addr += size;
len -= size;
list_add_tail(&chunk->node, &desc->chunks);
nchunks++;
}
}
desc->nchunks = nchunks;
desc->size = full_size;
/*
* Use hardware descriptor lists if possible when more than one chunk
* needs to be transferred (otherwise they don't make much sense).
*
* Source/Destination address should be located in same 4GiB region
* in the 40bit address space when it uses Hardware descriptor,
* and cross_boundary is checking it.
*/
desc->hwdescs.use = !cross_boundary && nchunks > 1;
if (desc->hwdescs.use) {
if (rcar_dmac_fill_hwdesc(chan, desc) < 0)
desc->hwdescs.use = false;
}
return &desc->async_tx;
}
/* -----------------------------------------------------------------------------
* DMA engine operations
*/
static int rcar_dmac_alloc_chan_resources(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
int ret;
INIT_LIST_HEAD(&rchan->desc.chunks_free);
INIT_LIST_HEAD(&rchan->desc.pages);
/* Preallocate descriptors. */
ret = rcar_dmac_xfer_chunk_alloc(rchan, GFP_KERNEL);
if (ret < 0)
return -ENOMEM;
ret = rcar_dmac_desc_alloc(rchan, GFP_KERNEL);
if (ret < 0)
return -ENOMEM;
return pm_runtime_get_sync(chan->device->dev);
}
static void rcar_dmac_free_chan_resources(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
struct rcar_dmac *dmac = to_rcar_dmac(chan->device);
struct rcar_dmac_chan_map *map = &rchan->map;
struct rcar_dmac_desc_page *page, *_page;
struct rcar_dmac_desc *desc;
LIST_HEAD(list);
/* Protect against ISR */
spin_lock_irq(&rchan->lock);
rcar_dmac_chan_halt(rchan);
spin_unlock_irq(&rchan->lock);
/*
* Now no new interrupts will occur, but one might already be
* running. Wait for it to finish before freeing resources.
*/
synchronize_irq(rchan->irq);
if (rchan->mid_rid >= 0) {
/* The caller is holding dma_list_mutex */
clear_bit(rchan->mid_rid, dmac->modules);
rchan->mid_rid = -EINVAL;
}
list_splice_init(&rchan->desc.free, &list);
list_splice_init(&rchan->desc.pending, &list);
list_splice_init(&rchan->desc.active, &list);
list_splice_init(&rchan->desc.done, &list);
list_splice_init(&rchan->desc.wait, &list);
rchan->desc.running = NULL;
list_for_each_entry(desc, &list, node)
rcar_dmac_realloc_hwdesc(rchan, desc, 0);
list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) {
list_del(&page->node);
free_page((unsigned long)page);
}
/* Remove slave mapping if present. */
if (map->slave.xfer_size) {
dma_unmap_resource(chan->device->dev, map->addr,
map->slave.xfer_size, map->dir, 0);
map->slave.xfer_size = 0;
}
pm_runtime_put(chan->device->dev);
}
static struct dma_async_tx_descriptor *
rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest,
dma_addr_t dma_src, size_t len, unsigned long flags)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
struct scatterlist sgl;
if (!len)
return NULL;
sg_init_table(&sgl, 1);
sg_set_page(&sgl, pfn_to_page(PFN_DOWN(dma_src)), len,
offset_in_page(dma_src));
sg_dma_address(&sgl) = dma_src;
sg_dma_len(&sgl) = len;
return rcar_dmac_chan_prep_sg(rchan, &sgl, 1, dma_dest,
DMA_MEM_TO_MEM, flags, false);
}
static int rcar_dmac_map_slave_addr(struct dma_chan *chan,
enum dma_transfer_direction dir)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
struct rcar_dmac_chan_map *map = &rchan->map;
phys_addr_t dev_addr;
size_t dev_size;
enum dma_data_direction dev_dir;
if (dir == DMA_DEV_TO_MEM) {
dev_addr = rchan->src.slave_addr;
dev_size = rchan->src.xfer_size;
dev_dir = DMA_TO_DEVICE;
} else {
dev_addr = rchan->dst.slave_addr;
dev_size = rchan->dst.xfer_size;
dev_dir = DMA_FROM_DEVICE;
}
/* Reuse current map if possible. */
if (dev_addr == map->slave.slave_addr &&
dev_size == map->slave.xfer_size &&
dev_dir == map->dir)
return 0;
/* Remove old mapping if present. */
if (map->slave.xfer_size)
dma_unmap_resource(chan->device->dev, map->addr,
map->slave.xfer_size, map->dir, 0);
map->slave.xfer_size = 0;
/* Create new slave address map. */
map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size,
dev_dir, 0);
if (dma_mapping_error(chan->device->dev, map->addr)) {
dev_err(chan->device->dev,
"chan%u: failed to map %zx@%pap", rchan->index,
dev_size, &dev_addr);
return -EIO;
}
dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n",
rchan->index, dev_size, &dev_addr, &map->addr,
dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE");
map->slave.slave_addr = dev_addr;
map->slave.xfer_size = dev_size;
map->dir = dev_dir;
return 0;
}
static struct dma_async_tx_descriptor *
rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction dir,
unsigned long flags, void *context)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
/* Someone calling slave DMA on a generic channel? */
if (rchan->mid_rid < 0 || !sg_len || !sg_dma_len(sgl)) {
dev_warn(chan->device->dev,
"%s: bad parameter: len=%d, id=%d\n",
__func__, sg_len, rchan->mid_rid);
return NULL;
}
if (rcar_dmac_map_slave_addr(chan, dir))
return NULL;
return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr,
dir, flags, false);
}
#define RCAR_DMAC_MAX_SG_LEN 32
static struct dma_async_tx_descriptor *
rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
size_t buf_len, size_t period_len,
enum dma_transfer_direction dir, unsigned long flags)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
struct dma_async_tx_descriptor *desc;
struct scatterlist *sgl;
unsigned int sg_len;
unsigned int i;
/* Someone calling slave DMA on a generic channel? */
if (rchan->mid_rid < 0 || buf_len < period_len) {
dev_warn(chan->device->dev,
"%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n",
__func__, buf_len, period_len, rchan->mid_rid);
return NULL;
}
if (rcar_dmac_map_slave_addr(chan, dir))
return NULL;
sg_len = buf_len / period_len;
if (sg_len > RCAR_DMAC_MAX_SG_LEN) {
dev_err(chan->device->dev,
"chan%u: sg length %d exceeds limit %d",
rchan->index, sg_len, RCAR_DMAC_MAX_SG_LEN);
return NULL;
}
/*
* Allocate the sg list dynamically as it would consume too much stack
* space.
*/
sgl = kmalloc_array(sg_len, sizeof(*sgl), GFP_NOWAIT);
if (!sgl)
return NULL;
sg_init_table(sgl, sg_len);
for (i = 0; i < sg_len; ++i) {
dma_addr_t src = buf_addr + (period_len * i);
sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len,
offset_in_page(src));
sg_dma_address(&sgl[i]) = src;
sg_dma_len(&sgl[i]) = period_len;
}
desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr,
dir, flags, true);
kfree(sgl);
return desc;
}
static int rcar_dmac_device_config(struct dma_chan *chan,
struct dma_slave_config *cfg)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
/*
* We could lock this, but you shouldn't be configuring the
* channel, while using it...
*/
rchan->src.slave_addr = cfg->src_addr;
rchan->dst.slave_addr = cfg->dst_addr;
rchan->src.xfer_size = cfg->src_addr_width;
rchan->dst.xfer_size = cfg->dst_addr_width;
return 0;
}
static int rcar_dmac_chan_terminate_all(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
unsigned long flags;
spin_lock_irqsave(&rchan->lock, flags);
rcar_dmac_chan_halt(rchan);
spin_unlock_irqrestore(&rchan->lock, flags);
/*
* FIXME: No new interrupt can occur now, but the IRQ thread might still
* be running.
*/
rcar_dmac_chan_reinit(rchan);
return 0;
}
static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan,
dma_cookie_t cookie)
{
struct rcar_dmac_desc *desc = chan->desc.running;
struct rcar_dmac_xfer_chunk *running = NULL;
struct rcar_dmac_xfer_chunk *chunk;
enum dma_status status;
unsigned int residue = 0;
unsigned int dptr = 0;
unsigned int chcrb;
unsigned int tcrb;
unsigned int i;
if (!desc)
return 0;
/*
* If the cookie corresponds to a descriptor that has been completed
* there is no residue. The same check has already been performed by the
* caller but without holding the channel lock, so the descriptor could
* now be complete.
*/
status = dma_cookie_status(&chan->chan, cookie, NULL);
if (status == DMA_COMPLETE)
return 0;
/*
* If the cookie doesn't correspond to the currently running transfer
* then the descriptor hasn't been processed yet, and the residue is
* equal to the full descriptor size.
* Also, a client driver is possible to call this function before
* rcar_dmac_isr_channel_thread() runs. In this case, the "desc.running"
* will be the next descriptor, and the done list will appear. So, if
* the argument cookie matches the done list's cookie, we can assume
* the residue is zero.
*/
if (cookie != desc->async_tx.cookie) {
list_for_each_entry(desc, &chan->desc.done, node) {
if (cookie == desc->async_tx.cookie)
return 0;
}
list_for_each_entry(desc, &chan->desc.pending, node) {
if (cookie == desc->async_tx.cookie)
return desc->size;
}
list_for_each_entry(desc, &chan->desc.active, node) {
if (cookie == desc->async_tx.cookie)
return desc->size;
}
/*
* No descriptor found for the cookie, there's thus no residue.
* This shouldn't happen if the calling driver passes a correct
* cookie value.
*/
WARN(1, "No descriptor for cookie!");
return 0;
}
/*
* We need to read two registers.
* Make sure the control register does not skip to next chunk
* while reading the counter.
* Trying it 3 times should be enough: Initial read, retry, retry
* for the paranoid.
*/
for (i = 0; i < 3; i++) {
chcrb = rcar_dmac_chan_read(chan, RCAR_DMACHCRB) &
RCAR_DMACHCRB_DPTR_MASK;
tcrb = rcar_dmac_chan_read(chan, RCAR_DMATCRB);
/* Still the same? */
if (chcrb == (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) &
RCAR_DMACHCRB_DPTR_MASK))
break;
}
WARN_ONCE(i >= 3, "residue might be not continuous!");
/*
* In descriptor mode the descriptor running pointer is not maintained
* by the interrupt handler, find the running descriptor from the
* descriptor pointer field in the CHCRB register. In non-descriptor
* mode just use the running descriptor pointer.
*/
if (desc->hwdescs.use) {
dptr = chcrb >> RCAR_DMACHCRB_DPTR_SHIFT;
if (dptr == 0)
dptr = desc->nchunks;
dptr--;
WARN_ON(dptr >= desc->nchunks);
} else {
running = desc->running;
}
/* Compute the size of all chunks still to be transferred. */
list_for_each_entry_reverse(chunk, &desc->chunks, node) {
if (chunk == running || ++dptr == desc->nchunks)
break;
residue += chunk->size;
}
/* Add the residue for the current chunk. */
residue += tcrb << desc->xfer_shift;
return residue;
}
static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
enum dma_status status;
unsigned long flags;
unsigned int residue;
bool cyclic;
status = dma_cookie_status(chan, cookie, txstate);
if (status == DMA_COMPLETE || !txstate)
return status;
spin_lock_irqsave(&rchan->lock, flags);
residue = rcar_dmac_chan_get_residue(rchan, cookie);
cyclic = rchan->desc.running ? rchan->desc.running->cyclic : false;
spin_unlock_irqrestore(&rchan->lock, flags);
/* if there's no residue, the cookie is complete */
if (!residue && !cyclic)
return DMA_COMPLETE;
dma_set_residue(txstate, residue);
return status;
}
static void rcar_dmac_issue_pending(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
unsigned long flags;
spin_lock_irqsave(&rchan->lock, flags);
if (list_empty(&rchan->desc.pending))
goto done;
/* Append the pending list to the active list. */
list_splice_tail_init(&rchan->desc.pending, &rchan->desc.active);
/*
* If no transfer is running pick the first descriptor from the active
* list and start the transfer.
*/
if (!rchan->desc.running) {
struct rcar_dmac_desc *desc;
desc = list_first_entry(&rchan->desc.active,
struct rcar_dmac_desc, node);
rchan->desc.running = desc;
rcar_dmac_chan_start_xfer(rchan);
}
done:
spin_unlock_irqrestore(&rchan->lock, flags);
}
static void rcar_dmac_device_synchronize(struct dma_chan *chan)
{
struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan);
synchronize_irq(rchan->irq);
}
/* -----------------------------------------------------------------------------
* IRQ handling
*/
static irqreturn_t rcar_dmac_isr_desc_stage_end(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc = chan->desc.running;
unsigned int stage;
if (WARN_ON(!desc || !desc->cyclic)) {
/*
* This should never happen, there should always be a running
* cyclic descriptor when a descriptor stage end interrupt is
* triggered. Warn and return.
*/
return IRQ_NONE;
}
/* Program the interrupt pointer to the next stage. */
stage = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) &
RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT;
rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(stage));
return IRQ_WAKE_THREAD;
}
static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan)
{
struct rcar_dmac_desc *desc = chan->desc.running;
irqreturn_t ret = IRQ_WAKE_THREAD;
if (WARN_ON_ONCE(!desc)) {
/*
* This should never happen, there should always be a running
* descriptor when a transfer end interrupt is triggered. Warn
* and return.
*/
return IRQ_NONE;
}
/*
* The transfer end interrupt isn't generated for each chunk when using
* descriptor mode. Only update the running chunk pointer in
* non-descriptor mode.
*/
if (!desc->hwdescs.use) {
/*
* If we haven't completed the last transfer chunk simply move
* to the next one. Only wake the IRQ thread if the transfer is
* cyclic.
*/
if (!list_is_last(&desc->running->node, &desc->chunks)) {
desc->running = list_next_entry(desc->running, node);
if (!desc->cyclic)
ret = IRQ_HANDLED;
goto done;
}
/*
* We've completed the last transfer chunk. If the transfer is
* cyclic, move back to the first one.
*/
if (desc->cyclic) {
desc->running =
list_first_entry(&desc->chunks,
struct rcar_dmac_xfer_chunk,
node);
goto done;
}
}
/* The descriptor is complete, move it to the done list. */
list_move_tail(&desc->node, &chan->desc.done);
/* Queue the next descriptor, if any. */
if (!list_empty(&chan->desc.active))
chan->desc.running = list_first_entry(&chan->desc.active,
struct rcar_dmac_desc,
node);
else
chan->desc.running = NULL;
done:
if (chan->desc.running)
rcar_dmac_chan_start_xfer(chan);
return ret;
}
static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev)
{
u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE;
struct rcar_dmac_chan *chan = dev;
irqreturn_t ret = IRQ_NONE;
bool reinit = false;
u32 chcr;
spin_lock(&chan->lock);
chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
if (chcr & RCAR_DMACHCR_CAE) {
struct rcar_dmac *dmac = to_rcar_dmac(chan->chan.device);
/*
* We don't need to call rcar_dmac_chan_halt()
* because channel is already stopped in error case.
* We need to clear register and check DE bit as recovery.
*/
rcar_dmac_chan_clear(dmac, chan);
rcar_dmac_chcr_de_barrier(chan);
reinit = true;
goto spin_lock_end;
}
if (chcr & RCAR_DMACHCR_TE)
mask |= RCAR_DMACHCR_DE;
rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask);
if (mask & RCAR_DMACHCR_DE)
rcar_dmac_chcr_de_barrier(chan);
if (chcr & RCAR_DMACHCR_DSE)
ret |= rcar_dmac_isr_desc_stage_end(chan);
if (chcr & RCAR_DMACHCR_TE)
ret |= rcar_dmac_isr_transfer_end(chan);
spin_lock_end:
spin_unlock(&chan->lock);
if (reinit) {
dev_err(chan->chan.device->dev, "Channel Address Error\n");
rcar_dmac_chan_reinit(chan);
ret = IRQ_HANDLED;
}
return ret;
}
static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev)
{
struct rcar_dmac_chan *chan = dev;
struct rcar_dmac_desc *desc;
struct dmaengine_desc_callback cb;
spin_lock_irq(&chan->lock);
/* For cyclic transfers notify the user after every chunk. */
if (chan->desc.running && chan->desc.running->cyclic) {
desc = chan->desc.running;
dmaengine_desc_get_callback(&desc->async_tx, &cb);
if (dmaengine_desc_callback_valid(&cb)) {
spin_unlock_irq(&chan->lock);
dmaengine_desc_callback_invoke(&cb, NULL);
spin_lock_irq(&chan->lock);
}
}
/*
* Call the callback function for all descriptors on the done list and
* move them to the ack wait list.
*/
while (!list_empty(&chan->desc.done)) {
desc = list_first_entry(&chan->desc.done, struct rcar_dmac_desc,
node);
dma_cookie_complete(&desc->async_tx);
list_del(&desc->node);
dmaengine_desc_get_callback(&desc->async_tx, &cb);
if (dmaengine_desc_callback_valid(&cb)) {
spin_unlock_irq(&chan->lock);
/*
* We own the only reference to this descriptor, we can
* safely dereference it without holding the channel
* lock.
*/
dmaengine_desc_callback_invoke(&cb, NULL);
spin_lock_irq(&chan->lock);
}
list_add_tail(&desc->node, &chan->desc.wait);
}
spin_unlock_irq(&chan->lock);
/* Recycle all acked descriptors. */
rcar_dmac_desc_recycle_acked(chan);
return IRQ_HANDLED;
}
/* -----------------------------------------------------------------------------
* OF xlate and channel filter
*/
static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg)
{
struct rcar_dmac *dmac = to_rcar_dmac(chan->device);
struct of_phandle_args *dma_spec = arg;
/*
* FIXME: Using a filter on OF platforms is a nonsense. The OF xlate
* function knows from which device it wants to allocate a channel from,
* and would be perfectly capable of selecting the channel it wants.
* Forcing it to call dma_request_channel() and iterate through all
* channels from all controllers is just pointless.
*/
if (chan->device->device_config != rcar_dmac_device_config)
return false;
return !test_and_set_bit(dma_spec->args[0], dmac->modules);
}
static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct rcar_dmac_chan *rchan;
struct dma_chan *chan;
dma_cap_mask_t mask;
if (dma_spec->args_count != 1)
return NULL;
/* Only slave DMA channels can be allocated via DT */
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
chan = __dma_request_channel(&mask, rcar_dmac_chan_filter, dma_spec,
ofdma->of_node);
if (!chan)
return NULL;
rchan = to_rcar_dmac_chan(chan);
rchan->mid_rid = dma_spec->args[0];
return chan;
}
/* -----------------------------------------------------------------------------
* Power management
*/
#ifdef CONFIG_PM
static int rcar_dmac_runtime_suspend(struct device *dev)
{
return 0;
}
static int rcar_dmac_runtime_resume(struct device *dev)
{
struct rcar_dmac *dmac = dev_get_drvdata(dev);
return rcar_dmac_init(dmac);
}
#endif
static const struct dev_pm_ops rcar_dmac_pm = {
/*
* TODO for system sleep/resume:
* - Wait for the current transfer to complete and stop the device,
* - Resume transfers, if any.
*/
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume,
NULL)
};
/* -----------------------------------------------------------------------------
* Probe and remove
*/
static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
struct rcar_dmac_chan *rchan)
{
struct platform_device *pdev = to_platform_device(dmac->dev);
struct dma_chan *chan = &rchan->chan;
char pdev_irqname[5];
char *irqname;
int ret;
rchan->mid_rid = -EINVAL;
spin_lock_init(&rchan->lock);
INIT_LIST_HEAD(&rchan->desc.free);
INIT_LIST_HEAD(&rchan->desc.pending);
INIT_LIST_HEAD(&rchan->desc.active);
INIT_LIST_HEAD(&rchan->desc.done);
INIT_LIST_HEAD(&rchan->desc.wait);
/* Request the channel interrupt. */
sprintf(pdev_irqname, "ch%u", rchan->index);
rchan->irq = platform_get_irq_byname(pdev, pdev_irqname);
if (rchan->irq < 0)
return -ENODEV;
irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u",
dev_name(dmac->dev), rchan->index);
if (!irqname)
return -ENOMEM;
/*
* Initialize the DMA engine channel and add it to the DMA engine
* channels list.
*/
chan->device = &dmac->engine;
dma_cookie_init(chan);
list_add_tail(&chan->device_node, &dmac->engine.channels);
ret = devm_request_threaded_irq(dmac->dev, rchan->irq,
rcar_dmac_isr_channel,
rcar_dmac_isr_channel_thread, 0,
irqname, rchan);
if (ret) {
dev_err(dmac->dev, "failed to request IRQ %u (%d)\n",
rchan->irq, ret);
return ret;
}
return 0;
}
#define RCAR_DMAC_MAX_CHANNELS 32
static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
{
struct device_node *np = dev->of_node;
int ret;
ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels);
if (ret < 0) {
dev_err(dev, "unable to read dma-channels property\n");
return ret;
}
/* The hardware and driver don't support more than 32 bits in CHCLR */
if (dmac->n_channels <= 0 ||
dmac->n_channels >= RCAR_DMAC_MAX_CHANNELS) {
dev_err(dev, "invalid number of channels %u\n",
dmac->n_channels);
return -EINVAL;
}
/*
* If the driver is unable to read dma-channel-mask property,
* the driver assumes that it can use all channels.
*/
dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask);
/* If the property has out-of-channel mask, this driver clears it */
dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0);
return 0;
}
static int rcar_dmac_probe(struct platform_device *pdev)
{
const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE |
DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES |
DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES |
DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES;
const struct rcar_dmac_of_data *data;
struct rcar_dmac_chan *chan;
struct dma_device *engine;
void __iomem *chan_base;
struct rcar_dmac *dmac;
unsigned int i;
int ret;
data = of_device_get_match_data(&pdev->dev);
if (!data)
return -EINVAL;
dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
if (!dmac)
return -ENOMEM;
dmac->dev = &pdev->dev;
platform_set_drvdata(pdev, dmac);
ret = dma_set_max_seg_size(dmac->dev, RCAR_DMATCR_MASK);
if (ret)
return ret;
ret = dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40));
if (ret)
return ret;
ret = rcar_dmac_parse_of(&pdev->dev, dmac);
if (ret < 0)
return ret;
/*
* A still unconfirmed hardware bug prevents the IPMMU microTLB 0 to be
* flushed correctly, resulting in memory corruption. DMAC 0 channel 0
* is connected to microTLB 0 on currently supported platforms, so we
* can't use it with the IPMMU. As the IOMMU API operates at the device
* level we can't disable it selectively, so ignore channel 0 for now if
* the device is part of an IOMMU group.
*/
if (device_iommu_mapped(&pdev->dev))
dmac->channels_mask &= ~BIT(0);
dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
sizeof(*dmac->channels), GFP_KERNEL);
if (!dmac->channels)
return -ENOMEM;
/* Request resources. */
dmac->dmac_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(dmac->dmac_base))
return PTR_ERR(dmac->dmac_base);
if (!data->chan_offset_base) {
dmac->chan_base = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(dmac->chan_base))
return PTR_ERR(dmac->chan_base);
chan_base = dmac->chan_base;
} else {
chan_base = dmac->dmac_base + data->chan_offset_base;
}
for_each_rcar_dmac_chan(i, dmac, chan) {
chan->index = i;
chan->iomem = chan_base + i * data->chan_offset_stride;
}
/* Enable runtime PM and initialize the device. */
pm_runtime_enable(&pdev->dev);
ret = pm_runtime_resume_and_get(&pdev->dev);
if (ret < 0) {
dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret);
goto err_pm_disable;
}
ret = rcar_dmac_init(dmac);
pm_runtime_put(&pdev->dev);
if (ret) {
dev_err(&pdev->dev, "failed to reset device\n");
goto err_pm_disable;
}
/* Initialize engine */
engine = &dmac->engine;
dma_cap_set(DMA_MEMCPY, engine->cap_mask);
dma_cap_set(DMA_SLAVE, engine->cap_mask);
engine->dev = &pdev->dev;
engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE);
engine->src_addr_widths = widths;
engine->dst_addr_widths = widths;
engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources;
engine->device_free_chan_resources = rcar_dmac_free_chan_resources;
engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy;
engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg;
engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic;
engine->device_config = rcar_dmac_device_config;
engine->device_pause = rcar_dmac_chan_pause;
engine->device_terminate_all = rcar_dmac_chan_terminate_all;
engine->device_tx_status = rcar_dmac_tx_status;
engine->device_issue_pending = rcar_dmac_issue_pending;
engine->device_synchronize = rcar_dmac_device_synchronize;
INIT_LIST_HEAD(&engine->channels);
for_each_rcar_dmac_chan(i, dmac, chan) {
ret = rcar_dmac_chan_probe(dmac, chan);
if (ret < 0)
goto err_pm_disable;
}
/* Register the DMAC as a DMA provider for DT. */
ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate,
NULL);
if (ret < 0)
goto err_pm_disable;
/*
* Register the DMA engine device.
*
* Default transfer size of 32 bytes requires 32-byte alignment.
*/
ret = dma_async_device_register(engine);
if (ret < 0)
goto err_dma_free;
return 0;
err_dma_free:
of_dma_controller_free(pdev->dev.of_node);
err_pm_disable:
pm_runtime_disable(&pdev->dev);
return ret;
}
static void rcar_dmac_remove(struct platform_device *pdev)
{
struct rcar_dmac *dmac = platform_get_drvdata(pdev);
of_dma_controller_free(pdev->dev.of_node);
dma_async_device_unregister(&dmac->engine);
pm_runtime_disable(&pdev->dev);
}
static void rcar_dmac_shutdown(struct platform_device *pdev)
{
struct rcar_dmac *dmac = platform_get_drvdata(pdev);
rcar_dmac_stop_all_chan(dmac);
}
static const struct rcar_dmac_of_data rcar_dmac_data = {
.chan_offset_base = 0x8000,
.chan_offset_stride = 0x80,
};
static const struct rcar_dmac_of_data rcar_gen4_dmac_data = {
.chan_offset_base = 0x0,
.chan_offset_stride = 0x1000,
};
static const struct of_device_id rcar_dmac_of_ids[] = {
{
.compatible = "renesas,rcar-dmac",
.data = &rcar_dmac_data,
}, {
.compatible = "renesas,rcar-gen4-dmac",
.data = &rcar_gen4_dmac_data,
}, {
.compatible = "renesas,dmac-r8a779a0",
.data = &rcar_gen4_dmac_data,
},
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids);
static struct platform_driver rcar_dmac_driver = {
.driver = {
.pm = &rcar_dmac_pm,
.name = "rcar-dmac",
.of_match_table = rcar_dmac_of_ids,
},
.probe = rcar_dmac_probe,
.remove_new = rcar_dmac_remove,
.shutdown = rcar_dmac_shutdown,
};
module_platform_driver(rcar_dmac_driver);
MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver");
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_LICENSE("GPL v2");