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linux/drivers/dma/s3c24xx-dma.c

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/*
* S3C24XX DMA handling
*
* Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
*
* based on 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.
*
* The DMA controllers in S3C24XX SoCs have a varying number of DMA signals
* that can be routed to any of the 4 to 8 hardware-channels.
*
* Therefore 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.
*
* Open items:
* - bursts
*/
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_data/dma-s3c24xx.h>
#include "dmaengine.h"
#include "virt-dma.h"
#define MAX_DMA_CHANNELS 8
#define S3C24XX_DISRC 0x00
#define S3C24XX_DISRCC 0x04
#define S3C24XX_DISRCC_INC_INCREMENT 0
#define S3C24XX_DISRCC_INC_FIXED BIT(0)
#define S3C24XX_DISRCC_LOC_AHB 0
#define S3C24XX_DISRCC_LOC_APB BIT(1)
#define S3C24XX_DIDST 0x08
#define S3C24XX_DIDSTC 0x0c
#define S3C24XX_DIDSTC_INC_INCREMENT 0
#define S3C24XX_DIDSTC_INC_FIXED BIT(0)
#define S3C24XX_DIDSTC_LOC_AHB 0
#define S3C24XX_DIDSTC_LOC_APB BIT(1)
#define S3C24XX_DIDSTC_INT_TC0 0
#define S3C24XX_DIDSTC_INT_RELOAD BIT(2)
#define S3C24XX_DCON 0x10
#define S3C24XX_DCON_TC_MASK 0xfffff
#define S3C24XX_DCON_DSZ_BYTE (0 << 20)
#define S3C24XX_DCON_DSZ_HALFWORD (1 << 20)
#define S3C24XX_DCON_DSZ_WORD (2 << 20)
#define S3C24XX_DCON_DSZ_MASK (3 << 20)
#define S3C24XX_DCON_DSZ_SHIFT 20
#define S3C24XX_DCON_AUTORELOAD 0
#define S3C24XX_DCON_NORELOAD BIT(22)
#define S3C24XX_DCON_HWTRIG BIT(23)
#define S3C24XX_DCON_HWSRC_SHIFT 24
#define S3C24XX_DCON_SERV_SINGLE 0
#define S3C24XX_DCON_SERV_WHOLE BIT(27)
#define S3C24XX_DCON_TSZ_UNIT 0
#define S3C24XX_DCON_TSZ_BURST4 BIT(28)
#define S3C24XX_DCON_INT BIT(29)
#define S3C24XX_DCON_SYNC_PCLK 0
#define S3C24XX_DCON_SYNC_HCLK BIT(30)
#define S3C24XX_DCON_DEMAND 0
#define S3C24XX_DCON_HANDSHAKE BIT(31)
#define S3C24XX_DSTAT 0x14
#define S3C24XX_DSTAT_STAT_BUSY BIT(20)
#define S3C24XX_DSTAT_CURRTC_MASK 0xfffff
#define S3C24XX_DMASKTRIG 0x20
#define S3C24XX_DMASKTRIG_SWTRIG BIT(0)
#define S3C24XX_DMASKTRIG_ON BIT(1)
#define S3C24XX_DMASKTRIG_STOP BIT(2)
#define S3C24XX_DMAREQSEL 0x24
#define S3C24XX_DMAREQSEL_HW BIT(0)
/*
* S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel
* for a DMA source. Instead only specific channels are valid.
* All of these SoCs have 4 physical channels and the number of request
* source bits is 3. Additionally we also need 1 bit to mark the channel
* as valid.
* Therefore we separate the chansel element of the channel data into 4
* parts of 4 bits each, to hold the information if the channel is valid
* and the hw request source to use.
*
* Example:
* SDI is valid on channels 0, 2 and 3 - with varying hw request sources.
* For it the chansel field would look like
*
* ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1
* ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2
* ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2
*/
#define S3C24XX_CHANSEL_WIDTH 4
#define S3C24XX_CHANSEL_VALID BIT(3)
#define S3C24XX_CHANSEL_REQ_MASK 7
/*
* struct soc_data - vendor-specific config parameters for individual SoCs
* @stride: spacing between the registers of each channel
* @has_reqsel: does the controller use the newer requestselection mechanism
* @has_clocks: are controllable dma-clocks present
*/
struct soc_data {
int stride;
bool has_reqsel;
bool has_clocks;
};
/*
* enum s3c24xx_dma_chan_state - holds the virtual channel states
* @S3C24XX_DMA_CHAN_IDLE: the channel is idle
* @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical transport
* channel and is running a transfer on it
* @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical transport
* channel to become available (only pertains to memcpy channels)
*/
enum s3c24xx_dma_chan_state {
S3C24XX_DMA_CHAN_IDLE,
S3C24XX_DMA_CHAN_RUNNING,
S3C24XX_DMA_CHAN_WAITING,
};
/*
* struct s3c24xx_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 s3c24xx_sg {
dma_addr_t src_addr;
dma_addr_t dst_addr;
size_t len;
struct list_head node;
};
/*
* struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor
* @vd: virtual DMA descriptor
* @dsg_list: list of children sg's
* @at: sg currently being transfered
* @width: transfer width
* @disrcc: value for source control register
* @didstc: value for destination control register
* @dcon: base value for dcon register
* @cyclic: indicate cyclic transfer
*/
struct s3c24xx_txd {
struct virt_dma_desc vd;
struct list_head dsg_list;
struct list_head *at;
u8 width;
u32 disrcc;
u32 didstc;
u32 dcon;
bool cyclic;
};
struct s3c24xx_dma_chan;
/*
* struct s3c24xx_dma_phy - holder for the physical channels
* @id: physical index to this channel
* @valid: does the channel have all required elements
* @base: virtual memory base (remapped) for the this channel
* @irq: interrupt for this channel
* @clk: clock for this channel
* @lock: a lock to use when altering an instance of this struct
* @serving: virtual channel currently being served by this physicalchannel
* @host: a pointer to the host (internal use)
*/
struct s3c24xx_dma_phy {
unsigned int id;
bool valid;
void __iomem *base;
int irq;
struct clk *clk;
spinlock_t lock;
struct s3c24xx_dma_chan *serving;
struct s3c24xx_dma_engine *host;
};
/*
* struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel
* @id: the id of the channel
* @name: name of the channel
* @vc: wrappped virtual channel
* @phy: the physical channel utilized by this channel, if there is one
* @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, running etc
* @slave: whether this channel is a device (slave) or for memcpy
*/
struct s3c24xx_dma_chan {
int id;
const char *name;
struct virt_dma_chan vc;
struct s3c24xx_dma_phy *phy;
struct dma_slave_config cfg;
struct s3c24xx_txd *at;
struct s3c24xx_dma_engine *host;
enum s3c24xx_dma_chan_state state;
bool slave;
};
/*
* struct s3c24xx_dma_engine - the local state holder for the S3C24XX
* @pdev: the corresponding platform device
* @pdata: platform data passed in from the platform/machine
* @base: virtual memory base (remapped)
* @slave: slave engine for this instance
* @memcpy: memcpy engine for this instance
* @phy_chans: array of data for the physical channels
*/
struct s3c24xx_dma_engine {
struct platform_device *pdev;
const struct s3c24xx_dma_platdata *pdata;
struct soc_data *sdata;
void __iomem *base;
struct dma_device slave;
struct dma_device memcpy;
struct s3c24xx_dma_phy *phy_chans;
};
/*
* Physical channel handling
*/
/*
* Check whether a certain channel is busy or not.
*/
static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy)
{
unsigned int val = readl(phy->base + S3C24XX_DSTAT);
return val & S3C24XX_DSTAT_STAT_BUSY;
}
static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan,
struct s3c24xx_dma_phy *phy)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
int phyvalid;
/* every phy is valid for memcopy channels */
if (!s3cchan->slave)
return true;
/* On newer variants all phys can be used for all virtual channels */
if (s3cdma->sdata->has_reqsel)
return true;
phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH));
return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false;
}
/*
* 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 s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
struct s3c24xx_dma_channel *cdata;
struct s3c24xx_dma_phy *phy = NULL;
unsigned long flags;
int i;
int ret;
if (s3cchan->slave)
cdata = &pdata->channels[s3cchan->id];
for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) {
phy = &s3cdma->phy_chans[i];
if (!phy->valid)
continue;
if (!s3c24xx_dma_phy_valid(s3cchan, phy))
continue;
spin_lock_irqsave(&phy->lock, flags);
if (!phy->serving) {
phy->serving = s3cchan;
spin_unlock_irqrestore(&phy->lock, flags);
break;
}
spin_unlock_irqrestore(&phy->lock, flags);
}
/* No physical channel available, cope with it */
if (i == s3cdma->pdata->num_phy_channels) {
dev_warn(&s3cdma->pdev->dev, "no phy channel available\n");
return NULL;
}
/* start the phy clock */
if (s3cdma->sdata->has_clocks) {
ret = clk_enable(phy->clk);
if (ret) {
dev_err(&s3cdma->pdev->dev, "could not enable clock for channel %d, err %d\n",
phy->id, ret);
phy->serving = NULL;
return NULL;
}
}
return phy;
}
/*
* Mark the physical channel as free.
*
* This drops the link between the physical and virtual channel.
*/
static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy)
{
struct s3c24xx_dma_engine *s3cdma = phy->host;
if (s3cdma->sdata->has_clocks)
clk_disable(phy->clk);
phy->serving = NULL;
}
/*
* Stops the channel by writing the stop bit.
* 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 s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy)
{
writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG);
}
/*
* Virtual channel handling
*/
static inline
struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan)
{
return container_of(chan, struct s3c24xx_dma_chan, vc.chan);
}
static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_phy *phy = s3cchan->phy;
struct s3c24xx_txd *txd = s3cchan->at;
u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK;
return tc * txd->width;
}
static int s3c24xx_dma_set_runtime_config(struct s3c24xx_dma_chan *s3cchan,
struct dma_slave_config *config)
{
if (!s3cchan->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;
s3cchan->cfg = *config;
return 0;
}
/*
* Transfer handling
*/
static inline
struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx)
{
return container_of(tx, struct s3c24xx_txd, vd.tx);
}
static struct s3c24xx_txd *s3c24xx_dma_get_txd(void)
{
struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
if (txd) {
INIT_LIST_HEAD(&txd->dsg_list);
txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD;
}
return txd;
}
static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd)
{
struct s3c24xx_sg *dsg, *_dsg;
list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
list_del(&dsg->node);
kfree(dsg);
}
kfree(txd);
}
static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan,
struct s3c24xx_txd *txd)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
struct s3c24xx_dma_phy *phy = s3cchan->phy;
const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node);
u32 dcon = txd->dcon;
u32 val;
/* transfer-size and -count from len and width */
switch (txd->width) {
case 1:
dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len;
break;
case 2:
dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2);
break;
case 4:
dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4);
break;
}
if (s3cchan->slave) {
struct s3c24xx_dma_channel *cdata =
&pdata->channels[s3cchan->id];
if (s3cdma->sdata->has_reqsel) {
writel_relaxed((cdata->chansel << 1) |
S3C24XX_DMAREQSEL_HW,
phy->base + S3C24XX_DMAREQSEL);
} else {
int csel = cdata->chansel >> (phy->id *
S3C24XX_CHANSEL_WIDTH);
csel &= S3C24XX_CHANSEL_REQ_MASK;
dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT;
dcon |= S3C24XX_DCON_HWTRIG;
}
} else {
if (s3cdma->sdata->has_reqsel)
writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL);
}
writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC);
writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC);
writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST);
writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC);
writel_relaxed(dcon, phy->base + S3C24XX_DCON);
val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG);
val &= ~S3C24XX_DMASKTRIG_STOP;
val |= S3C24XX_DMASKTRIG_ON;
/* trigger the dma operation for memcpy transfers */
if (!s3cchan->slave)
val |= S3C24XX_DMASKTRIG_SWTRIG;
writel(val, phy->base + S3C24XX_DMASKTRIG);
}
/*
* Set the initial DMA register values and start first sg.
*/
static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_phy *phy = s3cchan->phy;
struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc);
struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
list_del(&txd->vd.node);
s3cchan->at = txd;
/* Wait for channel inactive */
while (s3c24xx_dma_phy_busy(phy))
cpu_relax();
/* point to the first element of the sg list */
txd->at = txd->dsg_list.next;
s3c24xx_dma_start_next_sg(s3cchan, txd);
}
static void s3c24xx_dma_free_txd_list(struct s3c24xx_dma_engine *s3cdma,
struct s3c24xx_dma_chan *s3cchan)
{
LIST_HEAD(head);
vchan_get_all_descriptors(&s3cchan->vc, &head);
vchan_dma_desc_free_list(&s3cchan->vc, &head);
}
/*
* 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 s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
struct s3c24xx_dma_phy *phy;
phy = s3c24xx_dma_get_phy(s3cchan);
if (!phy) {
dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer on %s\n",
s3cchan->name);
s3cchan->state = S3C24XX_DMA_CHAN_WAITING;
return;
}
dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on %s\n",
phy->id, s3cchan->name);
s3cchan->phy = phy;
s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
s3c24xx_dma_start_next_txd(s3cchan);
}
static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy,
struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer on %s\n",
phy->id, s3cchan->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.
*/
phy->serving = s3cchan;
s3cchan->phy = phy;
s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
s3c24xx_dma_start_next_txd(s3cchan);
}
/*
* Free a physical DMA channel, potentially reallocating it to another
* virtual channel if we have any pending.
*/
static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan)
{
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
struct s3c24xx_dma_chan *p, *next;
retry:
next = NULL;
/* Find a waiting virtual channel for the next transfer. */
list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node)
if (p->state == S3C24XX_DMA_CHAN_WAITING) {
next = p;
break;
}
if (!next) {
list_for_each_entry(p, &s3cdma->slave.channels,
vc.chan.device_node)
if (p->state == S3C24XX_DMA_CHAN_WAITING &&
s3c24xx_dma_phy_valid(p, s3cchan->phy)) {
next = p;
break;
}
}
/* Ensure that the physical channel is stopped */
s3c24xx_dma_terminate_phy(s3cchan->phy);
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 == S3C24XX_DMA_CHAN_WAITING;
if (success)
s3c24xx_dma_phy_reassign_start(s3cchan->phy, 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 */
s3c24xx_dma_put_phy(s3cchan->phy);
}
s3cchan->phy = NULL;
s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
}
static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd)
{
struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd->tx.chan);
if (!s3cchan->slave)
dma_descriptor_unmap(&vd->tx);
s3c24xx_dma_free_txd(txd);
}
static irqreturn_t s3c24xx_dma_irq(int irq, void *data)
{
struct s3c24xx_dma_phy *phy = data;
struct s3c24xx_dma_chan *s3cchan = phy->serving;
struct s3c24xx_txd *txd;
dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy->id);
/*
* Interrupts happen to notify the completion of a transfer and the
* channel should have moved into its stop state already on its own.
* Therefore interrupts on channels not bound to a virtual channel
* should never happen. Nevertheless send a terminate command to the
* channel if the unlikely case happens.
*/
if (unlikely(!s3cchan)) {
dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n",
phy->id);
s3c24xx_dma_terminate_phy(phy);
return IRQ_HANDLED;
}
spin_lock(&s3cchan->vc.lock);
txd = s3cchan->at;
if (txd) {
/* when more sg's are in this txd, start the next one */
if (!list_is_last(txd->at, &txd->dsg_list)) {
txd->at = txd->at->next;
if (txd->cyclic)
vchan_cyclic_callback(&txd->vd);
s3c24xx_dma_start_next_sg(s3cchan, txd);
} else if (!txd->cyclic) {
s3cchan->at = NULL;
vchan_cookie_complete(&txd->vd);
/*
* And start the next descriptor (if any),
* otherwise free this channel.
*/
if (vchan_next_desc(&s3cchan->vc))
s3c24xx_dma_start_next_txd(s3cchan);
else
s3c24xx_dma_phy_free(s3cchan);
} else {
vchan_cyclic_callback(&txd->vd);
/* Cyclic: reset at beginning */
txd->at = txd->dsg_list.next;
s3c24xx_dma_start_next_sg(s3cchan, txd);
}
}
spin_unlock(&s3cchan->vc.lock);
return IRQ_HANDLED;
}
/*
* The DMA ENGINE API
*/
static int s3c24xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&s3cchan->vc.lock, flags);
switch (cmd) {
case DMA_SLAVE_CONFIG:
ret = s3c24xx_dma_set_runtime_config(s3cchan,
(struct dma_slave_config *)arg);
break;
case DMA_TERMINATE_ALL:
if (!s3cchan->phy && !s3cchan->at) {
dev_err(&s3cdma->pdev->dev, "trying to terminate already stopped channel %d\n",
s3cchan->id);
ret = -EINVAL;
break;
}
s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
/* Mark physical channel as free */
if (s3cchan->phy)
s3c24xx_dma_phy_free(s3cchan);
/* Dequeue current job */
if (s3cchan->at) {
s3c24xx_dma_desc_free(&s3cchan->at->vd);
s3cchan->at = NULL;
}
/* Dequeue jobs not yet fired as well */
s3c24xx_dma_free_txd_list(s3cdma, s3cchan);
break;
default:
/* Unknown command */
ret = -ENXIO;
break;
}
spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
return ret;
}
static int s3c24xx_dma_alloc_chan_resources(struct dma_chan *chan)
{
return 0;
}
static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan)
{
/* Ensure all queued descriptors are freed */
vchan_free_chan_resources(to_virt_chan(chan));
}
static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
struct s3c24xx_txd *txd;
struct s3c24xx_sg *dsg;
struct virt_dma_desc *vd;
unsigned long flags;
enum dma_status ret;
size_t bytes = 0;
spin_lock_irqsave(&s3cchan->vc.lock, flags);
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_COMPLETE) {
spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
return ret;
}
/*
* There's no point calculating the residue if there's
* no txstate to store the value.
*/
if (!txstate) {
spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
return ret;
}
vd = vchan_find_desc(&s3cchan->vc, cookie);
if (vd) {
/* On the issued list, so hasn't been processed yet */
txd = to_s3c24xx_txd(&vd->tx);
list_for_each_entry(dsg, &txd->dsg_list, node)
bytes += dsg->len;
} else {
/*
* Currently running, so sum over the pending sg's and
* the currently active one.
*/
txd = s3cchan->at;
dsg = list_entry(txd->at, struct s3c24xx_sg, node);
list_for_each_entry_from(dsg, &txd->dsg_list, node)
bytes += dsg->len;
bytes += s3c24xx_dma_getbytes_chan(s3cchan);
}
spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
/*
* This cookie not complete yet
* Get number of bytes left in the active transactions and queue
*/
dma_set_residue(txstate, bytes);
/* Whether waiting or running, we're in progress */
return ret;
}
/*
* Initialize a descriptor to be used by memcpy submit
*/
static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy(
struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t len, unsigned long flags)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
struct s3c24xx_txd *txd;
struct s3c24xx_sg *dsg;
int src_mod, dest_mod;
dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n",
len, s3cchan->name);
if ((len & S3C24XX_DCON_TC_MASK) != len) {
dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len);
return NULL;
}
txd = s3c24xx_dma_get_txd();
if (!txd)
return NULL;
dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
if (!dsg) {
s3c24xx_dma_free_txd(txd);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->src_addr = src;
dsg->dst_addr = dest;
dsg->len = len;
/*
* Determine a suitable transfer width.
* The DMA controller cannot fetch/store information which is not
* naturally aligned on the bus, i.e., a 4 byte fetch must start at
* an address divisible by 4 - more generally addr % width must be 0.
*/
src_mod = src % 4;
dest_mod = dest % 4;
switch (len % 4) {
case 0:
txd->width = (src_mod == 0 && dest_mod == 0) ? 4 : 1;
break;
case 2:
txd->width = ((src_mod == 2 || src_mod == 0) &&
(dest_mod == 2 || dest_mod == 0)) ? 2 : 1;
break;
default:
txd->width = 1;
break;
}
txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT;
txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT;
txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK |
S3C24XX_DCON_SERV_WHOLE;
return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
}
static struct dma_async_tx_descriptor *s3c24xx_dma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t addr, size_t size, size_t period,
enum dma_transfer_direction direction, unsigned long flags,
void *context)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
struct s3c24xx_txd *txd;
struct s3c24xx_sg *dsg;
unsigned sg_len;
dma_addr_t slave_addr;
u32 hwcfg = 0;
int i;
dev_dbg(&s3cdma->pdev->dev,
"prepare cyclic transaction of %zu bytes with period %zu from %s\n",
size, period, s3cchan->name);
if (!is_slave_direction(direction)) {
dev_err(&s3cdma->pdev->dev,
"direction %d unsupported\n", direction);
return NULL;
}
txd = s3c24xx_dma_get_txd();
if (!txd)
return NULL;
txd->cyclic = 1;
if (cdata->handshake)
txd->dcon |= S3C24XX_DCON_HANDSHAKE;
switch (cdata->bus) {
case S3C24XX_DMA_APB:
txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
hwcfg |= S3C24XX_DISRCC_LOC_APB;
break;
case S3C24XX_DMA_AHB:
txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
hwcfg |= S3C24XX_DISRCC_LOC_AHB;
break;
}
/*
* Always assume our peripheral desintation is a fixed
* address in memory.
*/
hwcfg |= S3C24XX_DISRCC_INC_FIXED;
/*
* Individual dma operations are requested by the slave,
* so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
*/
txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
if (direction == DMA_MEM_TO_DEV) {
txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
S3C24XX_DISRCC_INC_INCREMENT;
txd->didstc = hwcfg;
slave_addr = s3cchan->cfg.dst_addr;
txd->width = s3cchan->cfg.dst_addr_width;
} else {
txd->disrcc = hwcfg;
txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
S3C24XX_DIDSTC_INC_INCREMENT;
slave_addr = s3cchan->cfg.src_addr;
txd->width = s3cchan->cfg.src_addr_width;
}
sg_len = size / period;
for (i = 0; i < sg_len; i++) {
dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
if (!dsg) {
s3c24xx_dma_free_txd(txd);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->len = period;
/* Check last period length */
if (i == sg_len - 1)
dsg->len = size - period * i;
if (direction == DMA_MEM_TO_DEV) {
dsg->src_addr = addr + period * i;
dsg->dst_addr = slave_addr;
} else { /* DMA_DEV_TO_MEM */
dsg->src_addr = slave_addr;
dsg->dst_addr = addr + period * i;
}
}
return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
}
static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
struct s3c24xx_txd *txd;
struct s3c24xx_sg *dsg;
struct scatterlist *sg;
dma_addr_t slave_addr;
u32 hwcfg = 0;
int tmp;
dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from %s\n",
sg_dma_len(sgl), s3cchan->name);
txd = s3c24xx_dma_get_txd();
if (!txd)
return NULL;
if (cdata->handshake)
txd->dcon |= S3C24XX_DCON_HANDSHAKE;
switch (cdata->bus) {
case S3C24XX_DMA_APB:
txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
hwcfg |= S3C24XX_DISRCC_LOC_APB;
break;
case S3C24XX_DMA_AHB:
txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
hwcfg |= S3C24XX_DISRCC_LOC_AHB;
break;
}
/*
* Always assume our peripheral desintation is a fixed
* address in memory.
*/
hwcfg |= S3C24XX_DISRCC_INC_FIXED;
/*
* Individual dma operations are requested by the slave,
* so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
*/
txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
if (direction == DMA_MEM_TO_DEV) {
txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
S3C24XX_DISRCC_INC_INCREMENT;
txd->didstc = hwcfg;
slave_addr = s3cchan->cfg.dst_addr;
txd->width = s3cchan->cfg.dst_addr_width;
} else if (direction == DMA_DEV_TO_MEM) {
txd->disrcc = hwcfg;
txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
S3C24XX_DIDSTC_INC_INCREMENT;
slave_addr = s3cchan->cfg.src_addr;
txd->width = s3cchan->cfg.src_addr_width;
} else {
s3c24xx_dma_free_txd(txd);
dev_err(&s3cdma->pdev->dev,
"direction %d unsupported\n", direction);
return NULL;
}
for_each_sg(sgl, sg, sg_len, tmp) {
dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
if (!dsg) {
s3c24xx_dma_free_txd(txd);
return NULL;
}
list_add_tail(&dsg->node, &txd->dsg_list);
dsg->len = sg_dma_len(sg);
if (direction == DMA_MEM_TO_DEV) {
dsg->src_addr = sg_dma_address(sg);
dsg->dst_addr = slave_addr;
} else { /* DMA_DEV_TO_MEM */
dsg->src_addr = slave_addr;
dsg->dst_addr = sg_dma_address(sg);
}
}
return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
}
/*
* Slave transactions callback to the slave device to allow
* synchronization of slave DMA signals with the DMAC enable
*/
static void s3c24xx_dma_issue_pending(struct dma_chan *chan)
{
struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
unsigned long flags;
spin_lock_irqsave(&s3cchan->vc.lock, flags);
if (vchan_issue_pending(&s3cchan->vc)) {
if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING)
s3c24xx_dma_phy_alloc_and_start(s3cchan);
}
spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
}
/*
* Bringup and teardown
*/
/*
* Initialise the DMAC memcpy/slave channels.
* Make a local wrapper to hold required data
*/
static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine *s3cdma,
struct dma_device *dmadev, unsigned int channels, bool slave)
{
struct s3c24xx_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 = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL);
if (!chan) {
dev_err(dmadev->dev,
"%s no memory for channel\n", __func__);
return -ENOMEM;
}
chan->id = i;
chan->host = s3cdma;
chan->state = S3C24XX_DMA_CHAN_IDLE;
if (slave) {
chan->slave = true;
chan->name = kasprintf(GFP_KERNEL, "slave%d", i);
if (!chan->name)
return -ENOMEM;
} else {
chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
if (!chan->name)
return -ENOMEM;
}
dev_dbg(dmadev->dev,
"initialize virtual channel \"%s\"\n",
chan->name);
chan->vc.desc_free = s3c24xx_dma_desc_free;
vchan_init(&chan->vc, dmadev);
}
dev_info(dmadev->dev, "initialized %d virtual %s channels\n",
i, slave ? "slave" : "memcpy");
return i;
}
static void s3c24xx_dma_free_virtual_channels(struct dma_device *dmadev)
{
struct s3c24xx_dma_chan *chan = NULL;
struct s3c24xx_dma_chan *next;
list_for_each_entry_safe(chan,
next, &dmadev->channels, vc.chan.device_node)
list_del(&chan->vc.chan.device_node);
}
/* s3c2410, s3c2440 and s3c2442 have a 0x40 stride without separate clocks */
static struct soc_data soc_s3c2410 = {
.stride = 0x40,
.has_reqsel = false,
.has_clocks = false,
};
/* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */
static struct soc_data soc_s3c2412 = {
.stride = 0x40,
.has_reqsel = true,
.has_clocks = true,
};
/* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */
static struct soc_data soc_s3c2443 = {
.stride = 0x100,
.has_reqsel = true,
.has_clocks = true,
};
static struct platform_device_id s3c24xx_dma_driver_ids[] = {
{
.name = "s3c2410-dma",
.driver_data = (kernel_ulong_t)&soc_s3c2410,
}, {
.name = "s3c2412-dma",
.driver_data = (kernel_ulong_t)&soc_s3c2412,
}, {
.name = "s3c2443-dma",
.driver_data = (kernel_ulong_t)&soc_s3c2443,
},
{ },
};
static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device *pdev)
{
return (struct soc_data *)
platform_get_device_id(pdev)->driver_data;
}
static int s3c24xx_dma_probe(struct platform_device *pdev)
{
const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
struct s3c24xx_dma_engine *s3cdma;
struct soc_data *sdata;
struct resource *res;
int ret;
int i;
if (!pdata) {
dev_err(&pdev->dev, "platform data missing\n");
return -ENODEV;
}
/* Basic sanity check */
if (pdata->num_phy_channels > MAX_DMA_CHANNELS) {
dev_err(&pdev->dev, "to many dma channels %d, max %d\n",
pdata->num_phy_channels, MAX_DMA_CHANNELS);
return -EINVAL;
}
sdata = s3c24xx_dma_get_soc_data(pdev);
if (!sdata)
return -EINVAL;
s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL);
if (!s3cdma)
return -ENOMEM;
s3cdma->pdev = pdev;
s3cdma->pdata = pdata;
s3cdma->sdata = sdata;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
s3cdma->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(s3cdma->base))
return PTR_ERR(s3cdma->base);
s3cdma->phy_chans = devm_kzalloc(&pdev->dev,
sizeof(struct s3c24xx_dma_phy) *
pdata->num_phy_channels,
GFP_KERNEL);
if (!s3cdma->phy_chans)
return -ENOMEM;
/* aquire irqs and clocks for all physical channels */
for (i = 0; i < pdata->num_phy_channels; i++) {
struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
char clk_name[6];
phy->id = i;
phy->base = s3cdma->base + (i * sdata->stride);
phy->host = s3cdma;
phy->irq = platform_get_irq(pdev, i);
if (phy->irq < 0) {
dev_err(&pdev->dev, "failed to get irq %d, err %d\n",
i, phy->irq);
continue;
}
ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq,
0, pdev->name, phy);
if (ret) {
dev_err(&pdev->dev, "Unable to request irq for channel %d, error %d\n",
i, ret);
continue;
}
if (sdata->has_clocks) {
sprintf(clk_name, "dma.%d", i);
phy->clk = devm_clk_get(&pdev->dev, clk_name);
if (IS_ERR(phy->clk) && sdata->has_clocks) {
dev_err(&pdev->dev, "unable to aquire clock for channel %d, error %lu",
i, PTR_ERR(phy->clk));
continue;
}
ret = clk_prepare(phy->clk);
if (ret) {
dev_err(&pdev->dev, "clock for phy %d failed, error %d\n",
i, ret);
continue;
}
}
spin_lock_init(&phy->lock);
phy->valid = true;
dev_dbg(&pdev->dev, "physical channel %d is %s\n",
i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE");
}
/* Initialize memcpy engine */
dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask);
dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask);
s3cdma->memcpy.dev = &pdev->dev;
s3cdma->memcpy.device_alloc_chan_resources =
s3c24xx_dma_alloc_chan_resources;
s3cdma->memcpy.device_free_chan_resources =
s3c24xx_dma_free_chan_resources;
s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy;
s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status;
s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending;
s3cdma->memcpy.device_control = s3c24xx_dma_control;
/* Initialize slave engine for SoC internal dedicated peripherals */
dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask);
dma_cap_set(DMA_CYCLIC, s3cdma->slave.cap_mask);
dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask);
s3cdma->slave.dev = &pdev->dev;
s3cdma->slave.device_alloc_chan_resources =
s3c24xx_dma_alloc_chan_resources;
s3cdma->slave.device_free_chan_resources =
s3c24xx_dma_free_chan_resources;
s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status;
s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending;
s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg;
s3cdma->slave.device_prep_dma_cyclic = s3c24xx_dma_prep_dma_cyclic;
s3cdma->slave.device_control = s3c24xx_dma_control;
/* Register as many memcpy channels as there are physical channels */
ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy,
pdata->num_phy_channels, false);
if (ret <= 0) {
dev_warn(&pdev->dev,
"%s failed to enumerate memcpy channels - %d\n",
__func__, ret);
goto err_memcpy;
}
/* Register slave channels */
ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave,
pdata->num_channels, true);
if (ret <= 0) {
dev_warn(&pdev->dev,
"%s failed to enumerate slave channels - %d\n",
__func__, ret);
goto err_slave;
}
ret = dma_async_device_register(&s3cdma->memcpy);
if (ret) {
dev_warn(&pdev->dev,
"%s failed to register memcpy as an async device - %d\n",
__func__, ret);
goto err_memcpy_reg;
}
ret = dma_async_device_register(&s3cdma->slave);
if (ret) {
dev_warn(&pdev->dev,
"%s failed to register slave as an async device - %d\n",
__func__, ret);
goto err_slave_reg;
}
platform_set_drvdata(pdev, s3cdma);
dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n",
pdata->num_phy_channels);
return 0;
err_slave_reg:
dma_async_device_unregister(&s3cdma->memcpy);
err_memcpy_reg:
s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
err_slave:
s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
err_memcpy:
if (sdata->has_clocks)
for (i = 0; i < pdata->num_phy_channels; i++) {
struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
if (phy->valid)
clk_unprepare(phy->clk);
}
return ret;
}
static int s3c24xx_dma_remove(struct platform_device *pdev)
{
const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
struct s3c24xx_dma_engine *s3cdma = platform_get_drvdata(pdev);
struct soc_data *sdata = s3c24xx_dma_get_soc_data(pdev);
int i;
dma_async_device_unregister(&s3cdma->slave);
dma_async_device_unregister(&s3cdma->memcpy);
s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
if (sdata->has_clocks)
for (i = 0; i < pdata->num_phy_channels; i++) {
struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
if (phy->valid)
clk_unprepare(phy->clk);
}
return 0;
}
static struct platform_driver s3c24xx_dma_driver = {
.driver = {
.name = "s3c24xx-dma",
.owner = THIS_MODULE,
},
.id_table = s3c24xx_dma_driver_ids,
.probe = s3c24xx_dma_probe,
.remove = s3c24xx_dma_remove,
};
module_platform_driver(s3c24xx_dma_driver);
bool s3c24xx_dma_filter(struct dma_chan *chan, void *param)
{
struct s3c24xx_dma_chan *s3cchan;
if (chan->device->dev->driver != &s3c24xx_dma_driver.driver)
return false;
s3cchan = to_s3c24xx_dma_chan(chan);
return s3cchan->id == (int)param;
}
EXPORT_SYMBOL(s3c24xx_dma_filter);
MODULE_DESCRIPTION("S3C24XX DMA Driver");
MODULE_AUTHOR("Heiko Stuebner");
MODULE_LICENSE("GPL v2");
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