- 根目录:
- drivers
- dma
- amba-pl08x.c
/*
* Copyright (c) 2006 ARM Ltd.
* Copyright (c) 2010 ST-Ericsson SA
*
* Author: Peter Pearse <peter.pearse@arm.com>
* Author: Linus Walleij <linus.walleij@stericsson.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The full GNU General Public License is in this distribution in the file
* called COPYING.
*
* Documentation: ARM DDI 0196G == PL080
* Documentation: ARM DDI 0218E == PL081
* Documentation: S3C6410 User's Manual == PL080S
*
* PL080 & PL081 both have 16 sets of DMA signals that can be routed to any
* channel.
*
* The PL080 has 8 channels available for simultaneous use, and the PL081
* has only two channels. So on these DMA controllers the number of channels
* and the number of incoming DMA signals are two totally different things.
* It is usually not possible to theoretically handle all physical signals,
* so a multiplexing scheme with possible denial of use is necessary.
*
* The PL080 has a dual bus master, PL081 has a single master.
*
* PL080S is a version modified by Samsung and used in S3C64xx SoCs.
* It differs in following aspects:
* - CH_CONFIG register at different offset,
* - separate CH_CONTROL2 register for transfer size,
* - bigger maximum transfer size,
* - 8-word aligned LLI, instead of 4-word, due to extra CCTL2 word,
* - no support for peripheral flow control.
*
* Memory to peripheral transfer may be visualized as
* Get data from memory to DMAC
* Until no data left
* On burst request from peripheral
* Destination burst from DMAC to peripheral
* Clear burst request
* Raise terminal count interrupt
*
* For peripherals with a FIFO:
* Source burst size == half the depth of the peripheral FIFO
* Destination burst size == the depth of the peripheral FIFO
*
* (Bursts are irrelevant for mem to mem transfers - there are no burst
* signals, the DMA controller will simply facilitate its AHB master.)
*
* ASSUMES default (little) endianness for DMA transfers
*
* The PL08x has two flow control settings:
* - DMAC flow control: the transfer size defines the number of transfers
* which occur for the current LLI entry, and the DMAC raises TC at the
* end of every LLI entry. Observed behaviour shows the DMAC listening
* to both the BREQ and SREQ signals (contrary to documented),
* transferring data if either is active. The LBREQ and LSREQ signals
* are ignored.
*
* - Peripheral flow control: the transfer size is ignored (and should be
* zero). The data is transferred from the current LLI entry, until
* after the final transfer signalled by LBREQ or LSREQ. The DMAC
* will then move to the next LLI entry. Unsupported by PL080S.
*/
#include <linux/amba/bus.h>
#include <linux/amba/pl08x.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/amba/pl080.h>
#include "dmaengine.h"
#include "virt-dma.h"
#define DRIVER_NAME "pl08xdmac"
static struct amba_driver pl08x_amba_driver;
struct pl08x_driver_data;
/**
* struct vendor_data - vendor-specific config parameters for PL08x derivatives
* @channels: the number of channels available in this variant
* @dualmaster: whether this version supports dual AHB masters or not.
* @nomadik: whether the channels have Nomadik security extension bits
* that need to be checked for permission before use and some registers are
* missing
* @pl080s: whether this version is a PL080S, which has separate register and
* LLI word for transfer size.
*/
struct vendor_data {
u8 config_offset;
u8 channels;
bool dualmaster;
bool nomadik;
bool pl080s;
u32 max_transfer_size;
};
/**
* struct pl08x_bus_data - information of source or destination
* busses for a transfer
* @addr: current address
* @maxwidth: the maximum width of a transfer on this bus
* @buswidth: the width of this bus in bytes: 1, 2 or 4
*/
struct pl08x_bus_data {
dma_addr_t addr;
u8 maxwidth;
u8 buswidth;
};
#define IS_BUS_ALIGNED(bus) IS_ALIGNED((bus)->addr, (bus)->buswidth)
/**
* struct pl08x_phy_chan - holder for the physical channels
* @id: physical index to this channel
* @lock: a lock to use when altering an instance of this struct
* @serving: the virtual channel currently being served by this physical
* channel
* @locked: channel unavailable for the system, e.g. dedicated to secure
* world
*/
struct pl08x_phy_chan {
unsigned int id;
void __iomem *base;
void __iomem *reg_config;
spinlock_t lock;
struct pl08x_dma_chan *serving;
bool locked;
};
/**
* struct pl08x_sg - structure containing data per sg
* @src_addr: src address of sg
* @dst_addr: dst address of sg
* @len: transfer len in bytes
* @node: node for txd's dsg_list
*/
struct pl08x_sg {
dma_addr_t src_addr;
dma_addr_t dst_addr;
size_t len;
struct list_head node;
};
/**
* struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
* @vd: virtual DMA descriptor
* @dsg_list: list of children sg's
* @llis_bus: DMA memory address (physical) start for the LLIs
* @llis_va: virtual memory address start for the LLIs
* @cctl: control reg values for current txd
* @ccfg: config reg values for current txd
* @done: this marks completed descriptors, which should not have their
* mux released.
* @cyclic: indicate cyclic transfers
*/
struct pl08x_txd {
struct virt_dma_desc vd;
struct list_head dsg_list;
dma_addr_t llis_bus;
u32 *llis_va;
/* Default cctl value for LLIs */
u32 cctl;
/*
* Settings to be put into the physical channel when we
* trigger this txd. Other registers are in llis_va[0].
*/
u32 ccfg;
bool done;
bool cyclic;
};
/**
* struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
* states
* @PL08X_CHAN_IDLE: the channel is idle
* @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
* channel and is running a transfer on it
* @PL08X_CHAN_PAUSED: the channel has allocated a physical transport
* channel, but the transfer is currently paused
* @PL08X_CHAN_WAITING: the channel is waiting for a physical transport
* channel to become available (only pertains to memcpy channels)
*/
enum pl08x_dma_chan_state {
PL08X_CHAN_IDLE,
PL08X_CHAN_RUNNING,
PL08X_CHAN_PAUSED,
PL08X_CHAN_WAITING,
};
/**
* struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
* @vc: wrappped virtual channel
* @phychan: the physical channel utilized by this channel, if there is one
* @name: name of channel
* @cd: channel platform data
* @runtime_addr: address for RX/TX according to the runtime config
* @at: active transaction on this channel
* @lock: a lock for this channel data
* @host: a pointer to the host (internal use)
* @state: whether the channel is idle, paused, running etc
* @slave: whether this channel is a device (slave) or for memcpy
* @signal: the physical DMA request signal which this channel is using
* @mux_use: count of descriptors using this DMA request signal setting
*/
struct pl08x_dma_chan {
struct virt_dma_chan vc;
struct pl08x_phy_chan *phychan;
const char *name;
const struct pl08x_channel_data *cd;
struct dma_slave_config cfg;
struct pl08x_txd *at;
struct pl08x_driver_data *host;
enum pl08x_dma_chan_state state;
bool slave;
int signal;
unsigned mux_use;
};
/**
* struct pl08x_driver_data - the local state holder for the PL08x
* @slave: slave engine for this instance
* @memcpy: memcpy engine for this instance
* @base: virtual memory base (remapped) for the PL08x
* @adev: the corresponding AMBA (PrimeCell) bus entry
* @vd: vendor data for this PL08x variant
* @pd: platform data passed in from the platform/machine
* @phy_chans: array of data for the physical channels
* @pool: a pool for the LLI descriptors
* @lli_buses: bitmask to or in to LLI pointer selecting AHB port for LLI
* fetches
* @mem_buses: set to indicate memory transfers on AHB2.
* @lock: a spinlock for this struct
*/
struct pl08x_driver_data {
struct dma_device slave;
struct dma_device memcpy;
void __iomem *base;
struct amba_device *adev;
const struct vendor_data *vd;
struct pl08x_platform_data *pd;
struct pl08x_phy_chan *phy_chans;
struct dma_pool *pool;
u8 lli_buses;
u8 mem_buses;
u8 lli_words;
};
/*
* PL08X specific defines
*/
/* The order of words in an LLI. */
#define PL080_LLI_SRC 0
#define PL080_LLI_DST 1
#define PL080_LLI_LLI 2
#define PL080_LLI_CCTL 3
#define PL080S_LLI_CCTL2 4
/* Total words in an LLI. */
#define PL080_LLI_WORDS 4
#define PL080S_LLI_WORDS 8
/*
* Number of LLIs in each LLI buffer allocated for one transfer
* (maximum times we call dma_pool_alloc on this pool without freeing)
*/
#define MAX_NUM_TSFR_LLIS 512
#define PL08X_ALIGN 8
static inline struct pl08x_dma_chan *to_pl08x_chan(struct dma_chan *chan)
{
return container_of(chan, struct pl08x_dma_chan, vc.chan);
}
static inline struct pl08x_txd *to_pl08x_txd(struct dma_async_tx_descriptor *tx)
{
return container_of(tx, struct pl08x_txd, vd.tx);
}
/*
* Mux handling.
*
* This gives us the DMA request input to the PL08x primecell which the
* peripheral described by the channel data will be routed to, possibly
* via a board/SoC specific external MUX. One important point to note
* here is that this does not depend on the physical channel.
*/
static int pl08x_request_mux(struct pl08x_dma_chan *plchan)
{
const struct pl08x_platform_data *pd = plchan->host->pd;
int ret;
if (plchan->mux_use++ == 0 && pd->get_xfer_signal) {
ret = pd->get_xfer_signal(plchan->cd);
if (ret < 0) {
plchan->mux_use = 0;
return ret;
}
plchan->signal = ret;
}
return 0;
}
static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
{
const struct pl08x_platform_data *pd = plchan->host->pd;
if (plchan->signal >= 0) {
WARN_ON(plchan->mux_use == 0);
if (--plchan->mux_use == 0 && pd->put_xfer_signal) {
pd->put_xfer_signal(plchan->cd, plchan->signal);
plchan->signal = -1;
}
}
}
/*
* Physical channel handling
*/
/* Whether a certain channel is busy or not */
static int pl08x_phy_channel_busy(struct pl08x_phy_chan *ch)
{
unsigned int val;
val = readl(ch->reg_config);
return val & PL080_CONFIG_ACTIVE;
}
static void pl08x_write_lli(struct pl08x_driver_data *pl08x,
struct pl08x_phy_chan *phychan, const u32 *lli, u32 ccfg)
{
if (pl08x->vd->pl080s)
dev_vdbg(&pl08x->adev->dev,
"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
"clli=0x%08x, cctl=0x%08x, cctl2=0x%08x, ccfg=0x%08x\n",
phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL],
lli[PL080S_LLI_CCTL2], ccfg);
else
dev_vdbg(&pl08x->adev->dev,
"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
"clli=0x%08x, cctl=0x%08x, ccfg=0x%08x\n",
phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL], ccfg);
writel_relaxed(lli[PL080_LLI_SRC], phychan->base + PL080_CH_SRC_ADDR);
writel_relaxed(lli[PL080_LLI_DST], phychan->base + PL080_CH_DST_ADDR);
writel_relaxed(lli[PL080_LLI_LLI], phychan->base + PL080_CH_LLI);
writel_relaxed(lli[PL080_LLI_CCTL], phychan->base + PL080_CH_CONTROL);
if (pl08x->vd->pl080s)
writel_relaxed(lli[PL080S_LLI_CCTL2],
phychan->base + PL080S_CH_CONTROL2);
writel(ccfg, phychan->reg_config);
}
/*
* Set the initial DMA register values i.e. those for the first LLI
* The next LLI pointer and the configuration interrupt bit have
* been set when the LLIs were constructed. Poke them into the hardware
* and start the transfer.
*/
static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_phy_chan *phychan = plchan->phychan;
struct virt_dma_desc *vd = vchan_next_desc(&plchan->vc);
struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
u32 val;
list_del(&txd->vd.node);
plchan->at = txd;
/* Wait for channel inactive */
while (pl08x_phy_channel_busy(phychan))
cpu_relax();
pl08x_write_lli(pl08x, phychan, &txd->llis_va[0], txd->ccfg);
/* Enable the DMA channel */
/* Do not access config register until channel shows as disabled */
while (readl(pl08x->base + PL080_EN_CHAN) & (1 << phychan->id))
cpu_relax();
/* Do not access config register until channel shows as inactive */
val = readl(phychan->reg_config);
while ((val & PL080_CONFIG_ACTIVE) || (val & PL080_CONFIG_ENABLE))
val = readl(phychan->reg_config);
writel(val | PL080_CONFIG_ENABLE, phychan->reg_config);
}
/*
* Pause the channel by setting the HALT bit.
*
* For M->P transfers, pause the DMAC first and then stop the peripheral -
* the FIFO can only drain if the peripheral is still requesting data.
* (note: this can still timeout if the DMAC FIFO never drains of data.)
*
* For P->M transfers, disable the peripheral first to stop it filling
* the DMAC FIFO, and then pause the DMAC.
*/
static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
{
u32 val;
int timeout;
/* Set the HALT bit and wait for the FIFO to drain */
val = readl(ch->reg_config);
val |= PL080_CONFIG_HALT;
writel(val, ch->reg_config);
/* Wait for channel inactive */
for (timeout = 1000; timeout; timeout--) {
if (!pl08x_phy_channel_busy(ch))
break;
udelay(1);
}
if (pl08x_phy_channel_busy(ch))
pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);
}
static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
{
u32 val;
/* Clear the HALT bit */
val = readl(ch->reg_config);
val &= ~PL080_CONFIG_HALT;
writel(val, ch->reg_config);
}
/*
* pl08x_terminate_phy_chan() stops the channel, clears the FIFO and
* clears any pending interrupt status. This should not be used for
* an on-going transfer, but as a method of shutting down a channel
* (eg, when it's no longer used) or terminating a transfer.
*/
static void pl08x_terminate_phy_chan(struct pl08x_driver_data *pl08x,
struct pl08x_phy_chan *ch)
{
u32 val = readl(ch->reg_config);
val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
PL080_CONFIG_TC_IRQ_MASK);
writel(val, ch->reg_config);
writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
}
static inline u32 get_bytes_in_cctl(u32 cctl)
{
/* The source width defines the number of bytes */
u32 bytes = cctl & PL080_CONTROL_TRANSFER_SIZE_MASK;
cctl &= PL080_CONTROL_SWIDTH_MASK;
switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
case PL080_WIDTH_8BIT:
break;
case PL080_WIDTH_16BIT:
bytes *= 2;
break;
case PL080_WIDTH_32BIT:
bytes *= 4;
break;
}
return bytes;
}
static inline u32 get_bytes_in_cctl_pl080s(u32 cctl, u32 cctl1)
{
/* The source width defines the number of bytes */
u32 bytes = cctl1 & PL080S_CONTROL_TRANSFER_SIZE_MASK;
cctl &= PL080_CONTROL_SWIDTH_MASK;
switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
case PL080_WIDTH_8BIT:
break;
case PL080_WIDTH_16BIT:
bytes *= 2;
break;
case PL080_WIDTH_32BIT:
bytes *= 4;
break;
}
return bytes;
}
/* The channel should be paused when calling this */
static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
const u32 *llis_va, *llis_va_limit;
struct pl08x_phy_chan *ch;
dma_addr_t llis_bus;
struct pl08x_txd *txd;
u32 llis_max_words;
size_t bytes;
u32 clli;
ch = plchan->phychan;
txd = plchan->at;
if (!ch || !txd)
return 0;
/*
* Follow the LLIs to get the number of remaining
* bytes in the currently active transaction.
*/
clli = readl(ch->base + PL080_CH_LLI) & ~PL080_LLI_LM_AHB2;
/* First get the remaining bytes in the active transfer */
if (pl08x->vd->pl080s)
bytes = get_bytes_in_cctl_pl080s(
readl(ch->base + PL080_CH_CONTROL),
readl(ch->base + PL080S_CH_CONTROL2));
else
bytes = get_bytes_in_cctl(readl(ch->base + PL080_CH_CONTROL));
if (!clli)
return bytes;
llis_va = txd->llis_va;
llis_bus = txd->llis_bus;
llis_max_words = pl08x->lli_words * MAX_NUM_TSFR_LLIS;
BUG_ON(clli < llis_bus || clli >= llis_bus +
sizeof(u32) * llis_max_words);
/*
* Locate the next LLI - as this is an array,
* it's simple maths to find.
*/
llis_va += (clli - llis_bus) / sizeof(u32);
llis_va_limit = llis_va + llis_max_words;
for (; llis_va < llis_va_limit; llis_va += pl08x->lli_words) {
if (pl08x->vd->pl080s)
bytes += get_bytes_in_cctl_pl080s(
llis_va[PL080_LLI_CCTL],
llis_va[PL080S_LLI_CCTL2]);
else
bytes += get_bytes_in_cctl(llis_va[PL080_LLI_CCTL]);
/*
* A LLI pointer going backward terminates the LLI list
*/
if (llis_va[PL080_LLI_LLI] <= clli)
break;
}
return bytes;
}
/*
* Allocate a physical channel for a virtual channel
*
* Try to locate a physical channel to be used for this transfer. If all
* are taken return NULL and the requester will have to cope by using
* some fallback PIO mode or retrying later.
*/
static struct pl08x_phy_chan *
pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
struct pl08x_dma_chan *virt_chan)
{
struct pl08x_phy_chan *ch = NULL;
unsigned long flags;
int i;
for (i = 0; i < pl08x->vd->channels; i++) {
ch = &pl08x->phy_chans[i];
spin_lock_irqsave(&ch->lock, flags);
if (!ch->locked && !ch->serving) {
ch->serving = virt_chan;
spin_unlock_irqrestore(&ch->lock, flags);
break;
}
spin_unlock_irqrestore(&ch->lock, flags);
}
if (i == pl08x->vd->channels) {
/* No physical channel available, cope with it */
return NULL;
}
return ch;
}
/* Mark the physical channel as free. Note, this write is atomic. */
static inline void pl08x_put_phy_channel(struct pl08x_driver_data *pl08x,
struct pl08x_phy_chan *ch)
{
ch->serving = NULL;
}
/*
* Try to allocate a physical channel. When successful, assign it to
* this virtual channel, and initiate the next descriptor. The
* virtual channel lock must be held at this point.
*/
static void pl08x_phy_alloc_and_start(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_phy_chan *ch;
ch = pl08x_get_phy_channel(pl08x, plchan);
if (!ch) {
dev_dbg(&pl08x->adev->dev, "no physical channel available for xfer on %s\n", plchan->name);
plchan->state = PL08X_CHAN_WAITING;
return;
}
dev_dbg(&pl08x->adev->dev, "allocated physical channel %d for xfer on %s\n",
ch->id, plchan->name);
plchan->phychan = ch;
plchan->state = PL08X_CHAN_RUNNING;
pl08x_start_next_txd(plchan);
}
static void pl08x_phy_reassign_start(struct pl08x_phy_chan *ch,
struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
dev_dbg(&pl08x->adev->dev, "reassigned physical channel %d for xfer on %s\n",
ch->id, plchan->name);
/*
* We do this without taking the lock; we're really only concerned
* about whether this pointer is NULL or not, and we're guaranteed
* that this will only be called when it _already_ is non-NULL.
*/
ch->serving = plchan;
plchan->phychan = ch;
plchan->state = PL08X_CHAN_RUNNING;
pl08x_start_next_txd(plchan);
}
/*
* Free a physical DMA channel, potentially reallocating it to another
* virtual channel if we have any pending.
*/
static void pl08x_phy_free(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_dma_chan *p, *next;
retry:
next = NULL;
/* Find a waiting virtual channel for the next transfer. */
list_for_each_entry(p, &pl08x->memcpy.channels, vc.chan.device_node)
if (p->state == PL08X_CHAN_WAITING) {
next = p;
break;
}
if (!next) {
list_for_each_entry(p, &pl08x->slave.channels, vc.chan.device_node)
if (p->state == PL08X_CHAN_WAITING) {
next = p;
break;
}
}
/* Ensure that the physical channel is stopped */
pl08x_terminate_phy_chan(pl08x, plchan->phychan);
if (next) {
bool success;
/*
* Eww. We know this isn't going to deadlock
* but lockdep probably doesn't.
*/
spin_lock(&next->vc.lock);
/* Re-check the state now that we have the lock */
success = next->state == PL08X_CHAN_WAITING;
if (success)
pl08x_phy_reassign_start(plchan->phychan, next);
spin_unlock(&next->vc.lock);
/* If the state changed, try to find another channel */
if (!success)
goto retry;
} else {
/* No more jobs, so free up the physical channel */
pl08x_put_phy_channel(pl08x, plchan->phychan);
}
plchan->phychan = NULL;
plchan->state = PL08X_CHAN_IDLE;
}
/*
* LLI handling
*/
static inline unsigned int pl08x_get_bytes_for_cctl(unsigned int coded)
{
switch (coded) {
case PL080_WIDTH_8BIT:
return 1;
case PL080_WIDTH_16BIT:
return 2;
case PL080_WIDTH_32BIT:
return 4;
default:
break;
}
BUG();
return 0;
}
static inline u32 pl08x_cctl_bits(u32 cctl, u8 srcwidth, u8 dstwidth,
size_t tsize)
{
u32 retbits = cctl;
/* Remove all src, dst and transfer size bits */
retbits &= ~PL080_CONTROL_DWIDTH_MASK;
retbits &= ~PL080_CONTROL_SWIDTH_MASK;
retbits &= ~PL080_CONTROL_TRANSFER_SIZE_MASK;
/* Then set the bits according to the parameters */
switch (srcwidth) {
case 1:
retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_SWIDTH_SHIFT;
break;
case 2:
retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_SWIDTH_SHIFT;
break;
case 4:
retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_SWIDTH_SHIFT;
break;
default:
BUG();
break;
}
switch (dstwidth) {
case 1:
retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_DWIDTH_SHIFT;
break;
case 2:
retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_DWIDTH_SHIFT;
break;
case 4:
retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_DWIDTH_SHIFT;
break;
default:
BUG();
break;
}
tsize &= PL080_CONTROL_TRANSFER_SIZE_MASK;
retbits |= tsize << PL080_CONTROL_TRANSFER_SIZE_SHIFT;
return retbits;
}
struct pl08x_lli_build_data {
struct pl08x_txd *txd;
struct pl08x_bus_data srcbus;
struct pl08x_bus_data dstbus;
size_t remainder;
u32 lli_bus;
};
/*
* Autoselect a master bus to use for the transfer. Slave will be the chosen as
* victim in case src & dest are not similarly aligned. i.e. If after aligning
* masters address with width requirements of transfer (by sending few byte by
* byte data), slave is still not aligned, then its width will be reduced to
* BYTE.
* - prefers the destination bus if both available
* - prefers bus with fixed address (i.e. peripheral)
*/
static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
{
if (!(cctl & PL080_CONTROL_DST_INCR)) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
} else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
} else {
if (bd->dstbus.buswidth >= bd->srcbus.buswidth) {
*mbus = &bd->dstbus;
*sbus = &bd->srcbus;
} else {
*mbus = &bd->srcbus;
*sbus = &bd->dstbus;
}
}
}
/*
* Fills in one LLI for a certain transfer descriptor and advance the counter
*/
static void pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
struct pl08x_lli_build_data *bd,
int num_llis, int len, u32 cctl, u32 cctl2)
{
u32 offset = num_llis * pl08x->lli_words;
u32 *llis_va = bd->txd->llis_va + offset;
dma_addr_t llis_bus = bd->txd->llis_bus;
BUG_ON(num_llis >= MAX_NUM_TSFR_LLIS);
/* Advance the offset to next LLI. */
offset += pl08x->lli_words;
llis_va[PL080_LLI_SRC] = bd->srcbus.addr;
llis_va[PL080_LLI_DST] = bd->dstbus.addr;
llis_va[PL080_LLI_LLI] = (llis_bus + sizeof(u32) * offset);
llis_va[PL080_LLI_LLI] |= bd->lli_bus;
llis_va[PL080_LLI_CCTL] = cctl;
if (pl08x->vd->pl080s)
llis_va[PL080S_LLI_CCTL2] = cctl2;
if (cctl & PL080_CONTROL_SRC_INCR)
bd->srcbus.addr += len;
if (cctl & PL080_CONTROL_DST_INCR)
bd->dstbus.addr += len;
BUG_ON(bd->remainder < len);
bd->remainder -= len;
}
static inline void prep_byte_width_lli(struct pl08x_driver_data *pl08x,
struct pl08x_lli_build_data *bd, u32 *cctl, u32 len,
int num_llis, size_t *total_bytes)
{
*cctl = pl08x_cctl_bits(*cctl, 1, 1, len);
pl08x_fill_lli_for_desc(pl08x, bd, num_llis, len, *cctl, len);
(*total_bytes) += len;
}
#ifdef VERBOSE_DEBUG
static void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
const u32 *llis_va, int num_llis)
{
int i;
if (pl08x->vd->pl080s) {
dev_vdbg(&pl08x->adev->dev,
"%-3s %-9s %-10s %-10s %-10s %-10s %s\n",
"lli", "", "csrc", "cdst", "clli", "cctl", "cctl2");
for (i = 0; i < num_llis; i++) {
dev_vdbg(&pl08x->adev->dev,
"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x 0x%08x\n",
i, llis_va, llis_va[PL080_LLI_SRC],
llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
llis_va[PL080_LLI_CCTL],
llis_va[PL080S_LLI_CCTL2]);
llis_va += pl08x->lli_words;
}
} else {
dev_vdbg(&pl08x->adev->dev,
"%-3s %-9s %-10s %-10s %-10s %s\n",
"lli", "", "csrc", "cdst", "clli", "cctl");
for (i = 0; i < num_llis; i++) {
dev_vdbg(&pl08x->adev->dev,
"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x\n",
i, llis_va, llis_va[PL080_LLI_SRC],
llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
llis_va[PL080_LLI_CCTL]);
llis_va += pl08x->lli_words;
}
}
}
#else
static inline void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
const u32 *llis_va, int num_llis) {}
#endif
/*
* This fills in the table of LLIs for the transfer descriptor
* Note that we assume we never have to change the burst sizes
* Return 0 for error
*/
static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
struct pl08x_txd *txd)
{
struct pl08x_bus_data *mbus, *sbus;
struct pl08x_lli_build_data bd;
int num_llis = 0;
u32 cctl, early_bytes = 0;
size_t max_bytes_per_lli, total_bytes;
u32 *llis_va, *last_lli;
struct pl08x_sg *dsg;
txd->llis_va = dma_pool_alloc(pl08x->pool, GFP_NOWAIT, &txd->llis_bus);
if (!txd->llis_va) {
dev_err(&pl08x->adev->dev, "%s no memory for llis\n", __func__);
return 0;
}
bd.txd = txd;
bd.lli_bus = (pl08x->lli_buses & PL08X_AHB2) ? PL080_LLI_LM_AHB2 : 0;
cctl = txd->cctl;
/* Find maximum width of the source bus */
bd.srcbus.maxwidth =
pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_SWIDTH_MASK) >>
PL080_CONTROL_SWIDTH_SHIFT);
/* Find maximum width of the destination bus */
bd.dstbus.maxwidth =
pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_DWIDTH_MASK) >>
PL080_CONTROL_DWIDTH_SHIFT);
list_for_each_entry(dsg, &txd->dsg_list, node) {
total_bytes = 0;
cctl = txd->cctl;
bd.srcbus.addr = dsg->src_addr;
bd.dstbus.addr = dsg->dst_addr;
bd.remainder = dsg->len;
bd.srcbus.buswidth = bd.srcbus.maxwidth;
bd.dstbus.buswidth = bd.dstbus.maxwidth;
pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
dev_vdbg(&pl08x->adev->dev,
"src=0x%08llx%s/%u dst=0x%08llx%s/%u len=%zu\n",
(u64)bd.srcbus.addr,
cctl & PL080_CONTROL_SRC_INCR ? "+" : "",
bd.srcbus.buswidth,
(u64)bd.dstbus.addr,
cctl & PL080_CONTROL_DST_INCR ? "+" : "",
bd.dstbus.buswidth,
bd.remainder);
dev_vdbg(&pl08x->adev->dev, "mbus=%s sbus=%s\n",
mbus == &bd.srcbus ? "src" : "dst",
sbus == &bd.srcbus ? "src" : "dst");
/*
* Zero length is only allowed if all these requirements are
* met:
* - flow controller is peripheral.
* - src.addr is aligned to src.width
* - dst.addr is aligned to dst.width
*
* sg_len == 1 should be true, as there can be two cases here:
*
* - Memory addresses are contiguous and are not scattered.
* Here, Only one sg will be passed by user driver, with
* memory address and zero length. We pass this to controller
* and after the transfer it will receive the last burst
* request from peripheral and so transfer finishes.
*
* - Memory addresses are scattered and are not contiguous.
* Here, Obviously as DMA controller doesn't know when a lli's
* transfer gets over, it can't load next lli. So in this
* case, there has to be an assumption that only one lli is
* supported. Thus, we can't have scattered addresses.
*/
if (!bd.remainder) {
u32 fc = (txd->ccfg & PL080_CONFIG_FLOW_CONTROL_MASK) >>
PL080_CONFIG_FLOW_CONTROL_SHIFT;
if (!((fc >= PL080_FLOW_SRC2DST_DST) &&
(fc <= PL080_FLOW_SRC2DST_SRC))) {
dev_err(&pl08x->adev->dev, "%s sg len can't be zero",
__func__);
return 0;
}
if (!IS_BUS_ALIGNED(&bd.srcbus) ||
!IS_BUS_ALIGNED(&bd.dstbus)) {
dev_err(&pl08x->adev->dev,
"%s src & dst address must be aligned to src"
" & dst width if peripheral is flow controller",
__func__);
return 0;
}
cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
bd.dstbus.buswidth, 0);
pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
0, cctl, 0);
break;
}
/*
* Send byte by byte for following cases
* - Less than a bus width available
* - until master bus is aligned
*/
if (bd.remainder < mbus->buswidth)
early_bytes = bd.remainder;
else if (!IS_BUS_ALIGNED(mbus)) {
early_bytes = mbus->buswidth -
(mbus->addr & (mbus->buswidth - 1));
if ((bd.remainder - early_bytes) < mbus->buswidth)
early_bytes = bd.remainder;
}
if (early_bytes) {
dev_vdbg(&pl08x->adev->dev,
"%s byte width LLIs (remain 0x%08x)\n",
__func__, bd.remainder);
prep_byte_width_lli(pl08x, &bd, &cctl, early_bytes,
num_llis++, &total_bytes);
}
if (bd.remainder) {
/*
* Master now aligned
* - if slave is not then we must set its width down
*/
if (!IS_BUS_ALIGNED(sbus)) {
dev_dbg(&pl08x->adev->dev,
"%s set down bus width to one byte\n",
__func__);
sbus->buswidth = 1;
}
/*
* Bytes transferred = tsize * src width, not
* MIN(buswidths)
*/
max_bytes_per_lli = bd.srcbus.buswidth *
pl08x->vd->max_transfer_size;
dev_vdbg(&pl08x->adev->dev,
"%s max bytes per lli = %zu\n",
__func__, max_bytes_per_lli);
/*
* Make largest possible LLIs until less than one bus
* width left
*/
while (bd.remainder > (mbus->buswidth - 1)) {
size_t lli_len, tsize, width;
/*
* If enough left try to send max possible,
* otherwise try to send the remainder
*/
lli_len = min(bd.remainder, max_bytes_per_lli);
/*
* Check against maximum bus alignment:
* Calculate actual transfer size in relation to
* bus width an get a maximum remainder of the
* highest bus width - 1
*/
width = max(mbus->buswidth, sbus->buswidth);
lli_len = (lli_len / width) * width;
tsize = lli_len / bd.srcbus.buswidth;
dev_vdbg(&pl08x->adev->dev,
"%s fill lli with single lli chunk of "
"size 0x%08zx (remainder 0x%08zx)\n",
__func__, lli_len, bd.remainder);
cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
bd.dstbus.buswidth, tsize);
pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
lli_len, cctl, tsize);
total_bytes += lli_len;
}
/*
* Send any odd bytes
*/
if (bd.remainder) {
dev_vdbg(&pl08x->adev->dev,
"%s align with boundary, send odd bytes (remain %zu)\n",
__func__, bd.remainder);
prep_byte_width_lli(pl08x, &bd, &cctl,
bd.remainder, num_llis++, &total_bytes);
}
}
if (total_bytes != dsg->len) {
dev_err(&pl08x->adev->dev,
"%s size of encoded lli:s don't match total txd, transferred 0x%08zx from size 0x%08zx\n",
__func__, total_bytes, dsg->len);
return 0;
}
if (num_llis >= MAX_NUM_TSFR_LLIS) {
dev_err(&pl08x->adev->dev,
"%s need to increase MAX_NUM_TSFR_LLIS from 0x%08x\n",
__func__, MAX_NUM_TSFR_LLIS);
return 0;
}
}
llis_va = txd->llis_va;
last_lli = llis_va + (num_llis - 1) * pl08x->lli_words;
if (txd->cyclic) {
/* Link back to the first LLI. */
last_lli[PL080_LLI_LLI] = txd->llis_bus | bd.lli_bus;
} else {
/* The final LLI terminates the LLI. */
last_lli[PL080_LLI_LLI] = 0;
/* The final LLI element shall also fire an interrupt. */
last_lli[PL080_LLI_CCTL] |= PL080_CONTROL_TC_IRQ_EN;
}
pl08x_dump_lli(pl08x, llis_va, num_llis);
return num_llis;
}
static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
struct pl08x_txd *txd)
{
struct pl08x_sg *dsg, *_dsg;
if (txd->llis_va)
dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
list_del(&dsg->node);
kfree(dsg);
}
kfree(txd);
}
static void pl08x_desc_free(struct virt_dma_desc *vd)
{
struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
struct pl08x_dma_chan *plchan = to_pl08x_chan(vd->tx.chan);
dma_descriptor_unmap(&vd->tx);
if (!txd->done)
pl08x_release_mux(plchan);
pl08x_free_txd(plchan->host, txd);
}
static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,
struct pl08x_dma_chan *plchan)
{
LIST_HEAD(head);
vchan_get_all_descriptors(&plchan->vc, &head);
vchan_dma_desc_free_list(&plchan->vc, &head);
}
/*
* The DMA ENGINE API
*/
static int pl08x_alloc_chan_resources(struct dma_chan *chan)
{
return 0;
}
static void pl08x_free_chan_resources(struct dma_chan *chan)
{
/* Ensure all queued descriptors are freed */
vchan_free_chan_resources(to_virt_chan(chan));
}
static struct dma_async_tx_descriptor *pl08x_prep_dma_interrupt(
struct dma_chan *chan, unsigned long flags)
{
struct dma_async_tx_descriptor *retval = NULL;
return retval;
}
/*
* Code accessing dma_async_is_complete() in a tight loop may give problems.
* If slaves are relying on interrupts to signal completion this function
* must not be called with interrupts disabled.
*/
static enum dma_status pl08x_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct virt_dma_desc *vd;
unsigned long flags;
enum dma_status ret;
size_t bytes = 0;
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_COMPLETE)
return ret;
/*
* There's no point calculating the residue if there's
* no txstate to store the value.
*/
if (!txstate) {
if (plchan->state == PL08X_CHAN_PAUSED)
ret = DMA_PAUSED;
return ret;
}
spin_lock_irqsave(&plchan->vc.lock, flags);
ret = dma_cookie_status(chan, cookie, txstate);
if (ret != DMA_COMPLETE) {
vd = vchan_find_desc(&plchan->vc, cookie);
if (vd) {
/* On the issued list, so hasn't been processed yet */
struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
struct pl08x_sg *dsg;
list_for_each_entry(dsg, &txd->dsg_list, node)
bytes += dsg->len;
} else {
bytes = pl08x_getbytes_chan(plchan);
}
}
spin_unlock_irqrestore(&plchan->vc.lock, flags);
/*
* This cookie not complete yet
* Get number of bytes left in the active transactions and queue
*/
dma_set_residue(txstate, bytes);
if (plchan->state == PL08X_CHAN_PAUSED && ret == DMA_IN_PROGRESS)
ret = DMA_PAUSED;
/* Whether waiting or running, we're in progress */
return ret;
}
/* PrimeCell DMA extension */
struct burst_table {
u32 burstwords;
u32 reg;
};
static const struct burst_table burst_sizes[] = {
{
.burstwords = 256,
.reg = PL080_BSIZE_256,
},
{
.burstwords = 128,
.reg = PL080_BSIZE_128,
},
{
.burstwords = 64,
.reg = PL080_BSIZE_64,
},
{
.burstwords = 32,
.reg = PL080_BSIZE_32,
},
{
.burstwords = 16,
.reg = PL080_BSIZE_16,
},
{
.burstwords = 8,
.reg = PL080_BSIZE_8,
},
{
.burstwords = 4,
.reg = PL080_BSIZE_4,
},
{
.burstwords = 0,
.reg = PL080_BSIZE_1,
},
};
/*
* Given the source and destination available bus masks, select which
* will be routed to each port. We try to have source and destination
* on separate ports, but always respect the allowable settings.
*/
static u32 pl08x_select_bus(u8 src, u8 dst)
{
u32 cctl = 0;
if (!(dst & PL08X_AHB1) || ((dst & PL08X_AHB2) && (src & PL08X_AHB1)))
cctl |= PL080_CONTROL_DST_AHB2;
if (!(src & PL08X_AHB1) || ((src & PL08X_AHB2) && !(dst & PL08X_AHB2)))
cctl |= PL080_CONTROL_SRC_AHB2;
return cctl;
}
static u32 pl08x_cctl(u32 cctl)
{
cctl &= ~(PL080_CONTROL_SRC_AHB2 | PL080_CONTROL_DST_AHB2 |
PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR |
PL080_CONTROL_PROT_MASK);
/* Access the cell in privileged mode, non-bufferable, non-cacheable */
return cctl | PL080_CONTROL_PROT_SYS;
}
static u32 pl08x_width(enum dma_slave_buswidth width)
{
switch (width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
return PL080_WIDTH_8BIT;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
return PL080_WIDTH_16BIT;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
return PL080_WIDTH_32BIT;
default:
return ~0;
}
}
static u32 pl08x_burst(u32 maxburst)
{
int i;
for (i = 0; i < ARRAY_SIZE(burst_sizes); i++)
if (burst_sizes[i].burstwords <= maxburst)
break;
return burst_sizes[i].reg;
}
static u32 pl08x_get_cctl(struct pl08x_dma_chan *plchan,
enum dma_slave_buswidth addr_width, u32 maxburst)
{
u32 width, burst, cctl = 0;
width = pl08x_width(addr_width);
if (width == ~0)
return ~0;
cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
/*
* If this channel will only request single transfers, set this
* down to ONE element. Also select one element if no maxburst
* is specified.
*/
if (plchan->cd->single)
maxburst = 1;
burst = pl08x_burst(maxburst);
cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT;
cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT;
return pl08x_cctl(cctl);
}
static int dma_set_runtime_config(struct dma_chan *chan,
struct dma_slave_config *config)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
if (!plchan->slave)
return -EINVAL;
/* Reject definitely invalid configurations */
if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
return -EINVAL;
if (config->device_fc && pl08x->vd->pl080s) {
dev_err(&pl08x->adev->dev,
"%s: PL080S does not support peripheral flow control\n",
__func__);
return -EINVAL;
}
plchan->cfg = *config;
return 0;
}
/*
* Slave transactions callback to the slave device to allow
* synchronization of slave DMA signals with the DMAC enable
*/
static void pl08x_issue_pending(struct dma_chan *chan)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
unsigned long flags;
spin_lock_irqsave(&plchan->vc.lock, flags);
if (vchan_issue_pending(&plchan->vc)) {
if (!plchan->phychan && plchan->state != PL08X_CHAN_WAITING)
pl08x_phy_alloc_and_start(plchan);
}
spin_unlock_irqrestore(&plchan->vc.lock, flags);
}
static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan)
{
struct pl08x_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
if (txd) {
INIT_LIST_HEAD(&txd->dsg_list);
/* Always enable error and terminal interrupts */
txd->ccfg = PL080_CONFIG_ERR_IRQ_MASK |
PL080_CONFIG_TC_IRQ_MASK;
}
return txd;
}
/*
* Initialize a descriptor to be used by memcpy submit
*/
static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
struct pl08x_sg *dsg;
int ret;
txd = pl08x_get_txd(plchan);
if (!txd) {
dev_err(&pl08x->adev->dev,
"%s no memory for descriptor\n", __func__);
return NULL;
}
dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
if (!dsg) {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev, "%s no memory for pl080 sg\n",
__func__);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->src_addr = src;
dsg->dst_addr = dest;
dsg->len = len;
/* Set platform data for m2m */
txd->ccfg |= PL080_FLOW_MEM2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
txd->cctl = pl08x->pd->memcpy_channel.cctl_memcpy &
~(PL080_CONTROL_DST_AHB2 | PL080_CONTROL_SRC_AHB2);
/* Both to be incremented or the code will break */
txd->cctl |= PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR;
if (pl08x->vd->dualmaster)
txd->cctl |= pl08x_select_bus(pl08x->mem_buses,
pl08x->mem_buses);
ret = pl08x_fill_llis_for_desc(plchan->host, txd);
if (!ret) {
pl08x_free_txd(pl08x, txd);
return NULL;
}
return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
}
static struct pl08x_txd *pl08x_init_txd(
struct dma_chan *chan,
enum dma_transfer_direction direction,
dma_addr_t *slave_addr)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
enum dma_slave_buswidth addr_width;
int ret, tmp;
u8 src_buses, dst_buses;
u32 maxburst, cctl;
txd = pl08x_get_txd(plchan);
if (!txd) {
dev_err(&pl08x->adev->dev, "%s no txd\n", __func__);
return NULL;
}
/*
* Set up addresses, the PrimeCell configured address
* will take precedence since this may configure the
* channel target address dynamically at runtime.
*/
if (direction == DMA_MEM_TO_DEV) {
cctl = PL080_CONTROL_SRC_INCR;
*slave_addr = plchan->cfg.dst_addr;
addr_width = plchan->cfg.dst_addr_width;
maxburst = plchan->cfg.dst_maxburst;
src_buses = pl08x->mem_buses;
dst_buses = plchan->cd->periph_buses;
} else if (direction == DMA_DEV_TO_MEM) {
cctl = PL080_CONTROL_DST_INCR;
*slave_addr = plchan->cfg.src_addr;
addr_width = plchan->cfg.src_addr_width;
maxburst = plchan->cfg.src_maxburst;
src_buses = plchan->cd->periph_buses;
dst_buses = pl08x->mem_buses;
} else {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev,
"%s direction unsupported\n", __func__);
return NULL;
}
cctl |= pl08x_get_cctl(plchan, addr_width, maxburst);
if (cctl == ~0) {
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev,
"DMA slave configuration botched?\n");
return NULL;
}
txd->cctl = cctl | pl08x_select_bus(src_buses, dst_buses);
if (plchan->cfg.device_fc)
tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER_PER :
PL080_FLOW_PER2MEM_PER;
else
tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER :
PL080_FLOW_PER2MEM;
txd->ccfg |= tmp << PL080_CONFIG_FLOW_CONTROL_SHIFT;
ret = pl08x_request_mux(plchan);
if (ret < 0) {
pl08x_free_txd(pl08x, txd);
dev_dbg(&pl08x->adev->dev,
"unable to mux for transfer on %s due to platform restrictions\n",
plchan->name);
return NULL;
}
dev_dbg(&pl08x->adev->dev, "allocated DMA request signal %d for xfer on %s\n",
plchan->signal, plchan->name);
/* Assign the flow control signal to this channel */
if (direction == DMA_MEM_TO_DEV)
txd->ccfg |= plchan->signal << PL080_CONFIG_DST_SEL_SHIFT;
else
txd->ccfg |= plchan->signal << PL080_CONFIG_SRC_SEL_SHIFT;
return txd;
}
static int pl08x_tx_add_sg(struct pl08x_txd *txd,
enum dma_transfer_direction direction,
dma_addr_t slave_addr,
dma_addr_t buf_addr,
unsigned int len)
{
struct pl08x_sg *dsg;
dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
if (!dsg)
return -ENOMEM;
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->len = len;
if (direction == DMA_MEM_TO_DEV) {
dsg->src_addr = buf_addr;
dsg->dst_addr = slave_addr;
} else {
dsg->src_addr = slave_addr;
dsg->dst_addr = buf_addr;
}
return 0;
}
static struct dma_async_tx_descriptor *pl08x_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 pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
struct scatterlist *sg;
int ret, tmp;
dma_addr_t slave_addr;
dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
__func__, sg_dma_len(sgl), plchan->name);
txd = pl08x_init_txd(chan, direction, &slave_addr);
if (!txd)
return NULL;
for_each_sg(sgl, sg, sg_len, tmp) {
ret = pl08x_tx_add_sg(txd, direction, slave_addr,
sg_dma_address(sg),
sg_dma_len(sg));
if (ret) {
pl08x_release_mux(plchan);
pl08x_free_txd(pl08x, txd);
dev_err(&pl08x->adev->dev, "%s no mem for pl080 sg\n",
__func__);
return NULL;
}
}
ret = pl08x_fill_llis_for_desc(plchan->host, txd);
if (!ret) {
pl08x_release_mux(plchan);
pl08x_free_txd(pl08x, txd);
return NULL;
}
return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
}
static struct dma_async_tx_descriptor *pl08x_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
int ret, tmp;
dma_addr_t slave_addr;
dev_dbg(&pl08x->adev->dev,
"%s prepare cyclic transaction of %d/%d bytes %s %s\n",
__func__, period_len, buf_len,
direction == DMA_MEM_TO_DEV ? "to" : "from",
plchan->name);
txd = pl08x_init_txd(chan, direction, &slave_addr);
if (!txd)
return NULL;
txd->cyclic = true;
txd->cctl |= PL080_CONTROL_TC_IRQ_EN;
for (tmp = 0; tmp < buf_len; tmp += period_len) {
ret = pl08x_tx_add_sg(txd, direction, slave_addr,
buf_addr + tmp, period_len);
if (ret) {
pl08x_release_mux(plchan);
pl08x_free_txd(pl08x, txd);
return NULL;
}
}
ret = pl08x_fill_llis_for_desc(plchan->host, txd);
if (!ret) {
pl08x_release_mux(plchan);
pl08x_free_txd(pl08x, txd);
return NULL;
}
return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
}
static int pl08x_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
struct pl08x_driver_data *pl08x = plchan->host;
unsigned long flags;
int ret = 0;
/* Controls applicable to inactive channels */
if (cmd == DMA_SLAVE_CONFIG) {
return dma_set_runtime_config(chan,
(struct dma_slave_config *)arg);
}
/*
* Anything succeeds on channels with no physical allocation and
* no queued transfers.
*/
spin_lock_irqsave(&plchan->vc.lock, flags);
if (!plchan->phychan && !plchan->at) {
spin_unlock_irqrestore(&plchan->vc.lock, flags);
return 0;
}
switch (cmd) {
case DMA_TERMINATE_ALL:
plchan->state = PL08X_CHAN_IDLE;
if (plchan->phychan) {
/*
* Mark physical channel as free and free any slave
* signal
*/
pl08x_phy_free(plchan);
}
/* Dequeue jobs and free LLIs */
if (plchan->at) {
pl08x_desc_free(&plchan->at->vd);
plchan->at = NULL;
}
/* Dequeue jobs not yet fired as well */
pl08x_free_txd_list(pl08x, plchan);
break;
case DMA_PAUSE:
pl08x_pause_phy_chan(plchan->phychan);
plchan->state = PL08X_CHAN_PAUSED;
break;
case DMA_RESUME:
pl08x_resume_phy_chan(plchan->phychan);
plchan->state = PL08X_CHAN_RUNNING;
break;
default:
/* Unknown command */
ret = -ENXIO;
break;
}
spin_unlock_irqrestore(&plchan->vc.lock, flags);
return ret;
}
bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
{
struct pl08x_dma_chan *plchan;
char *name = chan_id;
/* Reject channels for devices not bound to this driver */
if (chan->device->dev->driver != &pl08x_amba_driver.drv)
return false;
plchan = to_pl08x_chan(chan);
/* Check that the channel is not taken! */
if (!strcmp(plchan->name, name))
return true;
return false;
}
EXPORT_SYMBOL_GPL(pl08x_filter_id);
/*
* Just check that the device is there and active
* TODO: turn this bit on/off depending on the number of physical channels
* actually used, if it is zero... well shut it off. That will save some
* power. Cut the clock at the same time.
*/
static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
{
/* The Nomadik variant does not have the config register */
if (pl08x->vd->nomadik)
return;
writel(PL080_CONFIG_ENABLE, pl08x->base + PL080_CONFIG);
}
static irqreturn_t pl08x_irq(int irq, void *dev)
{
struct pl08x_driver_data *pl08x = dev;
u32 mask = 0, err, tc, i;
/* check & clear - ERR & TC interrupts */
err = readl(pl08x->base + PL080_ERR_STATUS);
if (err) {
dev_err(&pl08x->adev->dev, "%s error interrupt, register value 0x%08x\n",
__func__, err);
writel(err, pl08x->base + PL080_ERR_CLEAR);
}
tc = readl(pl08x->base + PL080_TC_STATUS);
if (tc)
writel(tc, pl08x->base + PL080_TC_CLEAR);
if (!err && !tc)
return IRQ_NONE;
for (i = 0; i < pl08x->vd->channels; i++) {
if (((1 << i) & err) || ((1 << i) & tc)) {
/* Locate physical channel */
struct pl08x_phy_chan *phychan = &pl08x->phy_chans[i];
struct pl08x_dma_chan *plchan = phychan->serving;
struct pl08x_txd *tx;
if (!plchan) {
dev_err(&pl08x->adev->dev,
"%s Error TC interrupt on unused channel: 0x%08x\n",
__func__, i);
continue;
}
spin_lock(&plchan->vc.lock);
tx = plchan->at;
if (tx && tx->cyclic) {
vchan_cyclic_callback(&tx->vd);
} else if (tx) {
plchan->at = NULL;
/*
* This descriptor is done, release its mux
* reservation.
*/
pl08x_release_mux(plchan);
tx->done = true;
vchan_cookie_complete(&tx->vd);
/*
* And start the next descriptor (if any),
* otherwise free this channel.
*/
if (vchan_next_desc(&plchan->vc))
pl08x_start_next_txd(plchan);
else
pl08x_phy_free(plchan);
}
spin_unlock(&plchan->vc.lock);
mask |= (1 << i);
}
}
return mask ? IRQ_HANDLED : IRQ_NONE;
}
static void pl08x_dma_slave_init(struct pl08x_dma_chan *chan)
{
chan->slave = true;
chan->name = chan->cd->bus_id;
chan->cfg.src_addr = chan->cd->addr;
chan->cfg.dst_addr = chan->cd->addr;
}
/*
* Initialise the DMAC memcpy/slave channels.
* Make a local wrapper to hold required data
*/
static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
struct dma_device *dmadev, unsigned int channels, bool slave)
{
struct pl08x_dma_chan *chan;
int i;
INIT_LIST_HEAD(&dmadev->channels);
/*
* Register as many many memcpy as we have physical channels,
* we won't always be able to use all but the code will have
* to cope with that situation.
*/
for (i = 0; i < channels; i++) {
chan = kzalloc(sizeof(*chan), GFP_KERNEL);
if (!chan) {
dev_err(&pl08x->adev->dev,
"%s no memory for channel\n", __func__);
return -ENOMEM;
}
chan->host = pl08x;
chan->state = PL08X_CHAN_IDLE;
chan->signal = -1;
if (slave) {
chan->cd = &pl08x->pd->slave_channels[i];
pl08x_dma_slave_init(chan);
} else {
chan->cd = &pl08x->pd->memcpy_channel;
chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
if (!chan->name) {
kfree(chan);
return -ENOMEM;
}
}
dev_dbg(&pl08x->adev->dev,
"initialize virtual channel \"%s\"\n",
chan->name);
chan->vc.desc_free = pl08x_desc_free;
vchan_init(&chan->vc, dmadev);
}
dev_info(&pl08x->adev->dev, "initialized %d virtual %s channels\n",
i, slave ? "slave" : "memcpy");
return i;
}
static void pl08x_free_virtual_channels(struct dma_device *dmadev)
{
struct pl08x_dma_chan *chan = NULL;
struct pl08x_dma_chan *next;
list_for_each_entry_safe(chan,
next, &dmadev->channels, vc.chan.device_node) {
list_del(&chan->vc.chan.device_node);
kfree(chan);
}
}
#ifdef CONFIG_DEBUG_FS
static const char *pl08x_state_str(enum pl08x_dma_chan_state state)
{
switch (state) {
case PL08X_CHAN_IDLE:
return "idle";
case PL08X_CHAN_RUNNING:
return "running";
case PL08X_CHAN_PAUSED:
return "paused";
case PL08X_CHAN_WAITING:
return "waiting";
default:
break;
}
return "UNKNOWN STATE";
}
static int pl08x_debugfs_show(struct seq_file *s, void *data)
{
struct pl08x_driver_data *pl08x = s->private;
struct pl08x_dma_chan *chan;
struct pl08x_phy_chan *ch;
unsigned long flags;
int i;
seq_printf(s, "PL08x physical channels:\n");
seq_printf(s, "CHANNEL:\tUSER:\n");
seq_printf(s, "--------\t-----\n");
for (i = 0; i < pl08x->vd->channels; i++) {
struct pl08x_dma_chan *virt_chan;
ch = &pl08x->phy_chans[i];
spin_lock_irqsave(&ch->lock, flags);
virt_chan = ch->serving;
seq_printf(s, "%d\t\t%s%s\n",
ch->id,
virt_chan ? virt_chan->name : "(none)",
ch->locked ? " LOCKED" : "");
spin_unlock_irqrestore(&ch->lock, flags);
}
seq_printf(s, "\nPL08x virtual memcpy channels:\n");
seq_printf(s, "CHANNEL:\tSTATE:\n");
seq_printf(s, "--------\t------\n");
list_for_each_entry(chan, &pl08x->memcpy.channels, vc.chan.device_node) {
seq_printf(s, "%s\t\t%s\n", chan->name,
pl08x_state_str(chan->state));
}
seq_printf(s, "\nPL08x virtual slave channels:\n");
seq_printf(s, "CHANNEL:\tSTATE:\n");
seq_printf(s, "--------\t------\n");
list_for_each_entry(chan, &pl08x->slave.channels, vc.chan.device_node) {
seq_printf(s, "%s\t\t%s\n", chan->name,
pl08x_state_str(chan->state));
}
return 0;
}
static int pl08x_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, pl08x_debugfs_show, inode->i_private);
}
static const struct file_operations pl08x_debugfs_operations = {
.open = pl08x_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
{
/* Expose a simple debugfs interface to view all clocks */
(void) debugfs_create_file(dev_name(&pl08x->adev->dev),
S_IFREG | S_IRUGO, NULL, pl08x,
&pl08x_debugfs_operations);
}
#else
static inline void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
{
}
#endif
static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
{
struct pl08x_driver_data *pl08x;
const struct vendor_data *vd = id->data;
u32 tsfr_size;
int ret = 0;
int i;
ret = amba_request_regions(adev, NULL);
if (ret)
return ret;
/* Ensure that we can do DMA */
ret = dma_set_mask_and_coherent(&adev->dev, DMA_BIT_MASK(32));
if (ret)
goto out_no_pl08x;
/* Create the driver state holder */
pl08x = kzalloc(sizeof(*pl08x), GFP_KERNEL);
if (!pl08x) {
ret = -ENOMEM;
goto out_no_pl08x;
}
/* Initialize memcpy engine */
dma_cap_set(DMA_MEMCPY, pl08x->memcpy.cap_mask);
pl08x->memcpy.dev = &adev->dev;
pl08x->memcpy.device_alloc_chan_resources = pl08x_alloc_chan_resources;
pl08x->memcpy.device_free_chan_resources = pl08x_free_chan_resources;
pl08x->memcpy.device_prep_dma_memcpy = pl08x_prep_dma_memcpy;
pl08x->memcpy.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
pl08x->memcpy.device_tx_status = pl08x_dma_tx_status;
pl08x->memcpy.device_issue_pending = pl08x_issue_pending;
pl08x->memcpy.device_control = pl08x_control;
/* Initialize slave engine */
dma_cap_set(DMA_SLAVE, pl08x->slave.cap_mask);
dma_cap_set(DMA_CYCLIC, pl08x->slave.cap_mask);
pl08x->slave.dev = &adev->dev;
pl08x->slave.device_alloc_chan_resources = pl08x_alloc_chan_resources;
pl08x->slave.device_free_chan_resources = pl08x_free_chan_resources;
pl08x->slave.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
pl08x->slave.device_tx_status = pl08x_dma_tx_status;
pl08x->slave.device_issue_pending = pl08x_issue_pending;
pl08x->slave.device_prep_slave_sg = pl08x_prep_slave_sg;
pl08x->slave.device_prep_dma_cyclic = pl08x_prep_dma_cyclic;
pl08x->slave.device_control = pl08x_control;
/* Get the platform data */
pl08x->pd = dev_get_platdata(&adev->dev);
if (!pl08x->pd) {
dev_err(&adev->dev, "no platform data supplied\n");
ret = -EINVAL;
goto out_no_platdata;
}
/* Assign useful pointers to the driver state */
pl08x->adev = adev;
pl08x->vd = vd;
/* By default, AHB1 only. If dualmaster, from platform */
pl08x->lli_buses = PL08X_AHB1;
pl08x->mem_buses = PL08X_AHB1;
if (pl08x->vd->dualmaster) {
pl08x->lli_buses = pl08x->pd->lli_buses;
pl08x->mem_buses = pl08x->pd->mem_buses;
}
if (vd->pl080s)
pl08x->lli_words = PL080S_LLI_WORDS;
else
pl08x->lli_words = PL080_LLI_WORDS;
tsfr_size = MAX_NUM_TSFR_LLIS * pl08x->lli_words * sizeof(u32);
/* A DMA memory pool for LLIs, align on 1-byte boundary */
pl08x->pool = dma_pool_create(DRIVER_NAME, &pl08x->adev->dev,
tsfr_size, PL08X_ALIGN, 0);
if (!pl08x->pool) {
ret = -ENOMEM;
goto out_no_lli_pool;
}
pl08x->base = ioremap(adev->res.start, resource_size(&adev->res));
if (!pl08x->base) {
ret = -ENOMEM;
goto out_no_ioremap;
}
/* Turn on the PL08x */
pl08x_ensure_on(pl08x);
/* Attach the interrupt handler */
writel(0x000000FF, pl08x->base + PL080_ERR_CLEAR);
writel(0x000000FF, pl08x->base + PL080_TC_CLEAR);
ret = request_irq(adev->irq[0], pl08x_irq, 0, DRIVER_NAME, pl08x);
if (ret) {
dev_err(&adev->dev, "%s failed to request interrupt %d\n",
__func__, adev->irq[0]);
goto out_no_irq;
}
/* Initialize physical channels */
pl08x->phy_chans = kzalloc((vd->channels * sizeof(*pl08x->phy_chans)),
GFP_KERNEL);
if (!pl08x->phy_chans) {
dev_err(&adev->dev, "%s failed to allocate "
"physical channel holders\n",
__func__);
ret = -ENOMEM;
goto out_no_phychans;
}
for (i = 0; i < vd->channels; i++) {
struct pl08x_phy_chan *ch = &pl08x->phy_chans[i];
ch->id = i;
ch->base = pl08x->base + PL080_Cx_BASE(i);
ch->reg_config = ch->base + vd->config_offset;
spin_lock_init(&ch->lock);
/*
* Nomadik variants can have channels that are locked
* down for the secure world only. Lock up these channels
* by perpetually serving a dummy virtual channel.
*/
if (vd->nomadik) {
u32 val;
val = readl(ch->reg_config);
if (val & (PL080N_CONFIG_ITPROT | PL080N_CONFIG_SECPROT)) {
dev_info(&adev->dev, "physical channel %d reserved for secure access only\n", i);
ch->locked = true;
}
}
dev_dbg(&adev->dev, "physical channel %d is %s\n",
i, pl08x_phy_channel_busy(ch) ? "BUSY" : "FREE");
}
/* Register as many memcpy channels as there are physical channels */
ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->memcpy,
pl08x->vd->channels, false);
if (ret <= 0) {
dev_warn(&pl08x->adev->dev,
"%s failed to enumerate memcpy channels - %d\n",
__func__, ret);
goto out_no_memcpy;
}
pl08x->memcpy.chancnt = ret;
/* Register slave channels */
ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->slave,
pl08x->pd->num_slave_channels, true);
if (ret < 0) {
dev_warn(&pl08x->adev->dev,
"%s failed to enumerate slave channels - %d\n",
__func__, ret);
goto out_no_slave;
}
pl08x->slave.chancnt = ret;
ret = dma_async_device_register(&pl08x->memcpy);
if (ret) {
dev_warn(&pl08x->adev->dev,
"%s failed to register memcpy as an async device - %d\n",
__func__, ret);
goto out_no_memcpy_reg;
}
ret = dma_async_device_register(&pl08x->slave);
if (ret) {
dev_warn(&pl08x->adev->dev,
"%s failed to register slave as an async device - %d\n",
__func__, ret);
goto out_no_slave_reg;
}
amba_set_drvdata(adev, pl08x);
init_pl08x_debugfs(pl08x);
dev_info(&pl08x->adev->dev, "DMA: PL%03x%s rev%u at 0x%08llx irq %d\n",
amba_part(adev), pl08x->vd->pl080s ? "s" : "", amba_rev(adev),
(unsigned long long)adev->res.start, adev->irq[0]);
return 0;
out_no_slave_reg:
dma_async_device_unregister(&pl08x->memcpy);
out_no_memcpy_reg:
pl08x_free_virtual_channels(&pl08x->slave);
out_no_slave:
pl08x_free_virtual_channels(&pl08x->memcpy);
out_no_memcpy:
kfree(pl08x->phy_chans);
out_no_phychans:
free_irq(adev->irq[0], pl08x);
out_no_irq:
iounmap(pl08x->base);
out_no_ioremap:
dma_pool_destroy(pl08x->pool);
out_no_lli_pool:
out_no_platdata:
kfree(pl08x);
out_no_pl08x:
amba_release_regions(adev);
return ret;
}
/* PL080 has 8 channels and the PL080 have just 2 */
static struct vendor_data vendor_pl080 = {
.config_offset = PL080_CH_CONFIG,
.channels = 8,
.dualmaster = true,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
};
static struct vendor_data vendor_nomadik = {
.config_offset = PL080_CH_CONFIG,
.channels = 8,
.dualmaster = true,
.nomadik = true,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
};
static struct vendor_data vendor_pl080s = {
.config_offset = PL080S_CH_CONFIG,
.channels = 8,
.pl080s = true,
.max_transfer_size = PL080S_CONTROL_TRANSFER_SIZE_MASK,
};
static struct vendor_data vendor_pl081 = {
.config_offset = PL080_CH_CONFIG,
.channels = 2,
.dualmaster = false,
.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
};
static struct amba_id pl08x_ids[] = {
/* Samsung PL080S variant */
{
.id = 0x0a141080,
.mask = 0xffffffff,
.data = &vendor_pl080s,
},
/* PL080 */
{
.id = 0x00041080,
.mask = 0x000fffff,
.data = &vendor_pl080,
},
/* PL081 */
{
.id = 0x00041081,
.mask = 0x000fffff,
.data = &vendor_pl081,
},
/* Nomadik 8815 PL080 variant */
{
.id = 0x00280080,
.mask = 0x00ffffff,
.data = &vendor_nomadik,
},
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl08x_ids);
static struct amba_driver pl08x_amba_driver = {
.drv.name = DRIVER_NAME,
.id_table = pl08x_ids,
.probe = pl08x_probe,
};
static int __init pl08x_init(void)
{
int retval;
retval = amba_driver_register(&pl08x_amba_driver);
if (retval)
printk(KERN_WARNING DRIVER_NAME
"failed to register as an AMBA device (%d)\n",
retval);
return retval;
}
subsys_initcall(pl08x_init);