On Thu, May 16, 2024 at 05:25:58PM +0200, Amelie Delaunay wrote:
> On 5/15/24 20:56, Frank Li wrote:
> > On Tue, Apr 23, 2024 at 02:32:55PM +0200, Amelie Delaunay wrote:
> > > STM32 DMA3 driver supports the 3 hardware configurations of the STM32 DMA3
> > > controller:
...
> > > + writel_relaxed(hwdesc->cdar, ddata->base + STM32_DMA3_CDAR(id));
> > > + writel_relaxed(hwdesc->cllr, ddata->base + STM32_DMA3_CLLR(id));
> > > +
> > > + /* Clear any pending interrupts */
> > > + csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(id));
> > > + if (csr & CSR_ALL_F)
> > > + writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(id));
> > > +
> > > + stm32_dma3_chan_dump_reg(chan);
> > > +
> > > + ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(id));
> > > + writel_relaxed(ccr | CCR_EN, ddata->base + STM32_DMA3_CCR(id));
> >
> > This one should use writel instead of writel_relaxed because it need
> > dma_wmb() as barrier for preious write complete.
> >
> > Frank
> >
>
> ddata->base is Device memory type thanks to ioremap() use, so it is strongly
> ordered and non-cacheable.
> DMA3 is outside CPU cluster, its registers are accessible through AHB bus.
> dma_wmb() (in case of writel instead of writel_relaxed) is useless in that
> case: it won't ensure the propagation on the bus is complete, and it will
> have impacts on the system.
> That's why CCR register is written once, then it is read before CCR_EN is
> set and being written again, with _relaxed(), because registers are behind a
> bus, and ioremapped with Device memory type which ensures it is strongly
> ordered and non-cacheable.
regardless memory map, writel_relaxed() just make sure io write and read is
orderred, not necessary order with other memory access. only readl and
writel make sure order with other memory read/write.
1. Write src_addr to descriptor
2. dma_wmb()
3. Write "ready" to descriptor
4. enable channel or doorbell by write a register.
if 4 use writel_relaxe(). because 3 write to DDR, which difference place of
mmio, 4 may happen before 3. Your can refer axi order model.
4 have to use ONE writel(), to make sure 3 already write to DDR.
You need use at least one writel() to make sure all nornmal memory finish.
>
> > > +
> > > + chan->dma_status = DMA_IN_PROGRESS;
> > > +
> > > + dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
> > > +}
> > > +
> > > +static int stm32_dma3_chan_suspend(struct stm32_dma3_chan *chan, bool
> > > susp)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + u32 csr, ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) &
> > > ~CCR_EN;
> > > + int ret = 0;
> > > +
> > > + if (susp)
> > > + ccr |= CCR_SUSP;
> > > + else
> > > + ccr &= ~CCR_SUSP;
> > > +
> > > + writel_relaxed(ccr, ddata->base + STM32_DMA3_CCR(chan->id));
> > > +
> > > + if (susp) {
> > > + ret = readl_relaxed_poll_timeout_atomic(ddata->base +
> > > STM32_DMA3_CSR(chan->id), csr,
> > > + csr & CSR_SUSPF, 1, 10);
> > > + if (!ret)
> > > + writel_relaxed(CFCR_SUSPF, ddata->base +
> > > STM32_DMA3_CFCR(chan->id));
> > > +
> > > + stm32_dma3_chan_dump_reg(chan);
> > > + }
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static void stm32_dma3_chan_reset(struct stm32_dma3_chan *chan)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + u32 ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) &
> > > ~CCR_EN;
> > > +
> > > + writel_relaxed(ccr |= CCR_RESET, ddata->base +
> > > STM32_DMA3_CCR(chan->id));
> > > +}
> > > +
> > > +static int stm32_dma3_chan_stop(struct stm32_dma3_chan *chan)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + u32 ccr;
> > > + int ret = 0;
> > > +
> > > + chan->dma_status = DMA_COMPLETE;
> > > +
> > > + /* Disable interrupts */
> > > + ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id));
> > > + writel_relaxed(ccr & ~(CCR_ALLIE | CCR_EN), ddata->base +
> > > STM32_DMA3_CCR(chan->id));
> > > +
> > > + if (!(ccr & CCR_SUSP) && (ccr & CCR_EN)) {
> > > + /* Suspend the channel */
> > > + ret = stm32_dma3_chan_suspend(chan, true);
> > > + if (ret)
> > > + dev_warn(chan2dev(chan), "%s: timeout, data might be
> > > lost\n", __func__);
> > > + }
> > > +
> > > + /*
> > > + * Reset the channel: this causes the reset of the FIFO and the reset
> > > of the channel
> > > + * internal state, the reset of CCR_EN and CCR_SUSP bits.
> > > + */
> > > + stm32_dma3_chan_reset(chan);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static void stm32_dma3_chan_complete(struct stm32_dma3_chan *chan)
> > > +{
> > > + if (!chan->swdesc)
> > > + return;
> > > +
> > > + vchan_cookie_complete(&chan->swdesc->vdesc);
> > > + chan->swdesc = NULL;
> > > + stm32_dma3_chan_start(chan);
> > > +}
> > > +
> > > +static irqreturn_t stm32_dma3_chan_irq(int irq, void *devid)
> > > +{
> > > + struct stm32_dma3_chan *chan = devid;
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + u32 misr, csr, ccr;
> > > +
> > > + spin_lock(&chan->vchan.lock);
> > > +
> > > + misr = readl_relaxed(ddata->base + STM32_DMA3_MISR);
> > > + if (!(misr & MISR_MIS(chan->id))) {
> > > + spin_unlock(&chan->vchan.lock);
> > > + return IRQ_NONE;
> > > + }
> > > +
> > > + csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(chan->id));
> > > + ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & CCR_ALLIE;
> > > +
> > > + if (csr & CSR_TCF && ccr & CCR_TCIE) {
> > > + if (chan->swdesc->cyclic)
> > > + vchan_cyclic_callback(&chan->swdesc->vdesc);
> > > + else
> > > + stm32_dma3_chan_complete(chan);
> > > + }
> > > +
> > > + if (csr & CSR_USEF && ccr & CCR_USEIE) {
> > > + dev_err(chan2dev(chan), "User setting error\n");
> > > + chan->dma_status = DMA_ERROR;
> > > + /* CCR.EN automatically cleared by HW */
> > > + stm32_dma3_check_user_setting(chan);
> > > + stm32_dma3_chan_reset(chan);
> > > + }
> > > +
> > > + if (csr & CSR_ULEF && ccr & CCR_ULEIE) {
> > > + dev_err(chan2dev(chan), "Update link transfer error\n");
> > > + chan->dma_status = DMA_ERROR;
> > > + /* CCR.EN automatically cleared by HW */
> > > + stm32_dma3_chan_reset(chan);
> > > + }
> > > +
> > > + if (csr & CSR_DTEF && ccr & CCR_DTEIE) {
> > > + dev_err(chan2dev(chan), "Data transfer error\n");
> > > + chan->dma_status = DMA_ERROR;
> > > + /* CCR.EN automatically cleared by HW */
> > > + stm32_dma3_chan_reset(chan);
> > > + }
> > > +
> > > + /*
> > > + * Half Transfer Interrupt may be disabled but Half Transfer Flag can
> > > be set,
> > > + * ensure HTF flag to be cleared, with other flags.
> > > + */
> > > + csr &= (ccr | CCR_HTIE);
> > > +
> > > + if (csr)
> > > + writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(chan->id));
> > > +
> > > + spin_unlock(&chan->vchan.lock);
> > > +
> > > + return IRQ_HANDLED;
> > > +}
> > > +
> > > +static int stm32_dma3_alloc_chan_resources(struct dma_chan *c)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + u32 id = chan->id, csemcr, ccid;
> > > + int ret;
> > > +
> > > + ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
> > > + if (ret < 0)
> > > + return ret;
> >
> > It doesn't prefer runtime pm get at alloc dma chan, many client driver
> > doesn't actual user dma when allocate dma chan.
> >
> > Ideally, resume get when issue_pending. Please refer pl330.c.
> >
> > You may add runtime pm later after enablement patch.
> >
> > Frank
> >
>
> To well balance clock enable/disable, if pm_runtime_resume_and_get() (rather
> than pm_runtime_get_sync() which doesn't decrement the counter in case of
> error) is used when issue_pending, it means pm_runtime_put_sync() should be
> done when transfer ends.
>
> terminate_all is not always called, so put_sync can't be used only there, it
> should be conditionnally used in terminate_all, but also in interrupt
> handler, on error events and on transfer completion event, provided that it
> is the last transfer complete event (last item of the linked-list).
>
> For clients with high transfer rate, it means a lot of clock enable/disable.
> Moreover, DMA3 clock is managed by Secure OS. So it means a lot of
> non-secure/secure world transitions.
>
> I prefer to keep the implementation as it is for now, and possibly propose
> runtime pm improvement later, with autosuspend.
Autosuspend is perfered. we try to use pm_runtime_get/put at channel alloc
/free before, but this solution are rejected by community.
you can leave clock on for this enablement patch and add runtime pm later
time.
Frank
>
> Amelie
>
> > > +
> > > + /* Ensure the channel is free */
> > > + if (chan->semaphore_mode &&
> > > + readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id)) &
> > > CSEMCR_SEM_MUTEX) {
> > > + ret = -EBUSY;
> > > + goto err_put_sync;
> > > + }
> > > +
> > > + chan->lli_pool = dmam_pool_create(dev_name(&c->dev->device),
> > > c->device->dev,
> > > + sizeof(struct stm32_dma3_hwdesc),
> > > + __alignof__(struct
> > > stm32_dma3_hwdesc), 0);
> > > + if (!chan->lli_pool) {
> > > + dev_err(chan2dev(chan), "Failed to create LLI pool\n");
> > > + ret = -ENOMEM;
> > > + goto err_put_sync;
> > > + }
> > > +
> > > + /* Take the channel semaphore */
> > > + if (chan->semaphore_mode) {
> > > + writel_relaxed(CSEMCR_SEM_MUTEX, ddata->base +
> > > STM32_DMA3_CSEMCR(id));
> > > + csemcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(id));
> > > + ccid = FIELD_GET(CSEMCR_SEM_CCID, csemcr);
> > > + /* Check that the channel is well taken */
> > > + if (ccid != CCIDCFGR_CID1) {
> > > + dev_err(chan2dev(chan), "Not under CID1 control (in-use
> > > by CID%d)\n", ccid);
> > > + ret = -EPERM;
> > > + goto err_pool_destroy;
> > > + }
> > > + dev_dbg(chan2dev(chan), "Under CID1 control (semcr=0x%08x)\n",
> > > csemcr);
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +err_pool_destroy:
> > > + dmam_pool_destroy(chan->lli_pool);
> > > + chan->lli_pool = NULL;
> > > +
> > > +err_put_sync:
> > > + pm_runtime_put_sync(ddata->dma_dev.dev);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static void stm32_dma3_free_chan_resources(struct dma_chan *c)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + unsigned long flags;
> > > +
> > > + /* Ensure channel is in idle state */
> > > + spin_lock_irqsave(&chan->vchan.lock, flags);
> > > + stm32_dma3_chan_stop(chan);
> > > + chan->swdesc = NULL;
> > > + spin_unlock_irqrestore(&chan->vchan.lock, flags);
> > > +
> > > + vchan_free_chan_resources(to_virt_chan(c));
> > > +
> > > + dmam_pool_destroy(chan->lli_pool);
> > > + chan->lli_pool = NULL;
> > > +
> > > + /* Release the channel semaphore */
> > > + if (chan->semaphore_mode)
> > > + writel_relaxed(0, ddata->base + STM32_DMA3_CSEMCR(chan->id));
> > > +
> > > + pm_runtime_put_sync(ddata->dma_dev.dev);
> > > +
> > > + /* Reset configuration */
> > > + memset(&chan->dt_config, 0, sizeof(chan->dt_config));
> > > + memset(&chan->dma_config, 0, sizeof(chan->dma_config));
> > > +}
> > > +
> > > +static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct
> > > dma_chan *c,
> > > + struct
> > > scatterlist *sgl,
> > > + unsigned int
> > > sg_len,
> > > + enum
> > > dma_transfer_direction dir,
> > > + unsigned long
> > > flags, void *context)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + struct stm32_dma3_swdesc *swdesc;
> > > + struct scatterlist *sg;
> > > + size_t len;
> > > + dma_addr_t sg_addr, dev_addr, src, dst;
> > > + u32 i, j, count, ctr1, ctr2;
> > > + int ret;
> > > +
> > > + count = sg_len;
> > > + for_each_sg(sgl, sg, sg_len, i) {
> > > + len = sg_dma_len(sg);
> > > + if (len > STM32_DMA3_MAX_BLOCK_SIZE)
> > > + count += DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE) -
> > > 1;
> > > + }
> > > +
> > > + swdesc = stm32_dma3_chan_desc_alloc(chan, count);
> > > + if (!swdesc)
> > > + return NULL;
> > > +
> > > + /* sg_len and i correspond to the initial sgl; count and j correspond
> > > to the hwdesc LL */
> > > + j = 0;
> > > + for_each_sg(sgl, sg, sg_len, i) {
> > > + sg_addr = sg_dma_address(sg);
> > > + dev_addr = (dir == DMA_MEM_TO_DEV) ? chan->dma_config.dst_addr :
> > > + chan->dma_config.src_addr;
> > > + len = sg_dma_len(sg);
> > > +
> > > + do {
> > > + size_t chunk = min_t(size_t, len,
> > > STM32_DMA3_MAX_BLOCK_SIZE);
> > > +
> > > + if (dir == DMA_MEM_TO_DEV) {
> > > + src = sg_addr;
> > > + dst = dev_addr;
> > > +
> > > + ret = stm32_dma3_chan_prep_hw(chan, dir,
> > > &swdesc->ccr, &ctr1, &ctr2,
> > > + src, dst, chunk);
> > > +
> > > + if (FIELD_GET(CTR1_DINC, ctr1))
> > > + dev_addr += chunk;
> > > + } else { /* (dir == DMA_DEV_TO_MEM || dir ==
> > > DMA_MEM_TO_MEM) */
> > > + src = dev_addr;
> > > + dst = sg_addr;
> > > +
> > > + ret = stm32_dma3_chan_prep_hw(chan, dir,
> > > &swdesc->ccr, &ctr1, &ctr2,
> > > + src, dst, chunk);
> > > +
> > > + if (FIELD_GET(CTR1_SINC, ctr1))
> > > + dev_addr += chunk;
> > > + }
> > > +
> > > + if (ret)
> > > + goto err_desc_free;
> > > +
> > > + stm32_dma3_chan_prep_hwdesc(chan, swdesc, j, src, dst,
> > > chunk,
> > > + ctr1, ctr2, j == (count -
> > > 1), false);
> > > +
> > > + sg_addr += chunk;
> > > + len -= chunk;
> > > + j++;
> > > + } while (len);
> > > + }
> > > +
> > > + /* Enable Error interrupts */
> > > + swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
> > > + /* Enable Transfer state interrupts */
> > > + swdesc->ccr |= CCR_TCIE;
> > > +
> > > + swdesc->cyclic = false;
> > > +
> > > + return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
> > > +
> > > +err_desc_free:
> > > + stm32_dma3_chan_desc_free(chan, swdesc);
> > > +
> > > + return NULL;
> > > +}
> > > +
> > > +static void stm32_dma3_caps(struct dma_chan *c, struct dma_slave_caps
> > > *caps)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > +
> > > + if (!chan->fifo_size) {
> > > + caps->max_burst = 0;
> > > + caps->src_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + caps->dst_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + } else {
> > > + /* Burst transfer should not exceed half of the fifo size */
> > > + caps->max_burst = chan->max_burst;
> > > + if (caps->max_burst < DMA_SLAVE_BUSWIDTH_8_BYTES) {
> > > + caps->src_addr_widths &=
> > > ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + caps->dst_addr_widths &=
> > > ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + }
> > > + }
> > > +}
> > > +
> > > +static int stm32_dma3_config(struct dma_chan *c, struct dma_slave_config
> > > *config)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > +
> > > + memcpy(&chan->dma_config, config, sizeof(*config));
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int stm32_dma3_terminate_all(struct dma_chan *c)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + unsigned long flags;
> > > + LIST_HEAD(head);
> > > +
> > > + spin_lock_irqsave(&chan->vchan.lock, flags);
> > > +
> > > + if (chan->swdesc) {
> > > + vchan_terminate_vdesc(&chan->swdesc->vdesc);
> > > + chan->swdesc = NULL;
> > > + }
> > > +
> > > + stm32_dma3_chan_stop(chan);
> > > +
> > > + vchan_get_all_descriptors(&chan->vchan, &head);
> > > +
> > > + spin_unlock_irqrestore(&chan->vchan.lock, flags);
> > > + vchan_dma_desc_free_list(&chan->vchan, &head);
> > > +
> > > + dev_dbg(chan2dev(chan), "vchan %pK: terminated\n", &chan->vchan);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void stm32_dma3_synchronize(struct dma_chan *c)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > +
> > > + vchan_synchronize(&chan->vchan);
> > > +}
> > > +
> > > +static void stm32_dma3_issue_pending(struct dma_chan *c)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + unsigned long flags;
> > > +
> > > + spin_lock_irqsave(&chan->vchan.lock, flags);
> > > +
> > > + if (vchan_issue_pending(&chan->vchan) && !chan->swdesc) {
> > > + dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
> > > + stm32_dma3_chan_start(chan);
> > > + }
> > > +
> > > + spin_unlock_irqrestore(&chan->vchan.lock, flags);
> > > +}
> > > +
> > > +static bool stm32_dma3_filter_fn(struct dma_chan *c, void *fn_param)
> > > +{
> > > + struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
> > > + struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
> > > + struct stm32_dma3_dt_conf *conf = fn_param;
> > > + u32 mask, semcr;
> > > + int ret;
> > > +
> > > + dev_dbg(c->device->dev, "%s(%s): req_line=%d ch_conf=%08x
> > > tr_conf=%08x\n",
> > > + __func__, dma_chan_name(c), conf->req_line, conf->ch_conf,
> > > conf->tr_conf);
> > > +
> > > + if (!of_property_read_u32(c->device->dev->of_node, "dma-channel-mask",
> > > &mask))
> > > + if (!(mask & BIT(chan->id)))
> > > + return false;
> > > +
> > > + ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
> > > + if (ret < 0)
> > > + return false;
> > > + semcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
> > > + pm_runtime_put_sync(ddata->dma_dev.dev);
> > > +
> > > + /* Check if chan is free */
> > > + if (semcr & CSEMCR_SEM_MUTEX)
> > > + return false;
> > > +
> > > + /* Check if chan fifo fits well */
> > > + if (FIELD_GET(STM32_DMA3_DT_FIFO, conf->ch_conf) != chan->fifo_size)
> > > + return false;
> > > +
> > > + return true;
> > > +}
> > > +
> > > +static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args
> > > *dma_spec, struct of_dma *ofdma)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = ofdma->of_dma_data;
> > > + dma_cap_mask_t mask = ddata->dma_dev.cap_mask;
> > > + struct stm32_dma3_dt_conf conf;
> > > + struct stm32_dma3_chan *chan;
> > > + struct dma_chan *c;
> > > +
> > > + if (dma_spec->args_count < 3) {
> > > + dev_err(ddata->dma_dev.dev, "Invalid args count\n");
> > > + return NULL;
> > > + }
> > > +
> > > + conf.req_line = dma_spec->args[0];
> > > + conf.ch_conf = dma_spec->args[1];
> > > + conf.tr_conf = dma_spec->args[2];
> > > +
> > > + if (conf.req_line >= ddata->dma_requests) {
> > > + dev_err(ddata->dma_dev.dev, "Invalid request line\n");
> > > + return NULL;
> > > + }
> > > +
> > > + /* Request dma channel among the generic dma controller list */
> > > + c = dma_request_channel(mask, stm32_dma3_filter_fn, &conf);
> > > + if (!c) {
> > > + dev_err(ddata->dma_dev.dev, "No suitable channel found\n");
> > > + return NULL;
> > > + }
> > > +
> > > + chan = to_stm32_dma3_chan(c);
> > > + chan->dt_config = conf;
> > > +
> > > + return c;
> > > +}
> > > +
> > > +static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
> > > +{
> > > + u32 chan_reserved, mask = 0, i, ccidcfgr, invalid_cid = 0;
> > > +
> > > + /* Reserve Secure channels */
> > > + chan_reserved = readl_relaxed(ddata->base + STM32_DMA3_SECCFGR);
> > > +
> > > + /*
> > > + * CID filtering must be configured to ensure that the DMA3 channel
> > > will inherit the CID of
> > > + * the processor which is configuring and using the given channel.
> > > + * In case CID filtering is not configured, dma-channel-mask property
> > > can be used to
> > > + * specify available DMA channels to the kernel.
> > > + */
> > > + of_property_read_u32(ddata->dma_dev.dev->of_node, "dma-channel-mask",
> > > &mask);
> > > +
> > > + /* Reserve !CID-filtered not in dma-channel-mask, static CID != CID1,
> > > CID1 not allowed */
> > > + for (i = 0; i < ddata->dma_channels; i++) {
> > > + ccidcfgr = readl_relaxed(ddata->base + STM32_DMA3_CCIDCFGR(i));
> > > +
> > > + if (!(ccidcfgr & CCIDCFGR_CFEN)) { /* !CID-filtered */
> > > + invalid_cid |= BIT(i);
> > > + if (!(mask & BIT(i))) /* Not in dma-channel-mask */
> > > + chan_reserved |= BIT(i);
> > > + } else { /* CID-filtered */
> > > + if (!(ccidcfgr & CCIDCFGR_SEM_EN)) { /* Static CID mode
> > > */
> > > + if (FIELD_GET(CCIDCFGR_SCID, ccidcfgr) !=
> > > CCIDCFGR_CID1)
> > > + chan_reserved |= BIT(i);
> > > + } else { /* Semaphore mode */
> > > + if (!FIELD_GET(CCIDCFGR_SEM_WLIST_CID1,
> > > ccidcfgr))
> > > + chan_reserved |= BIT(i);
> > > + ddata->chans[i].semaphore_mode = true;
> > > + }
> > > + }
> > > + dev_dbg(ddata->dma_dev.dev, "chan%d: %s mode, %s\n", i,
> > > + !(ccidcfgr & CCIDCFGR_CFEN) ? "!CID-filtered" :
> > > + ddata->chans[i].semaphore_mode ? "Semaphore" : "Static
> > > CID",
> > > + (chan_reserved & BIT(i)) ? "denied" :
> > > + mask & BIT(i) ? "force allowed" : "allowed");
> > > + }
> > > +
> > > + if (invalid_cid)
> > > + dev_warn(ddata->dma_dev.dev, "chan%*pbl have invalid CID
> > > configuration\n",
> > > + ddata->dma_channels, &invalid_cid);
> > > +
> > > + return chan_reserved;
> > > +}
> > > +
> > > +static const struct of_device_id stm32_dma3_of_match[] = {
> > > + { .compatible = "st,stm32-dma3", },
> > > + { /* sentinel */},
> > > +};
> > > +MODULE_DEVICE_TABLE(of, stm32_dma3_of_match);
> > > +
> > > +static int stm32_dma3_probe(struct platform_device *pdev)
> > > +{
> > > + struct device_node *np = pdev->dev.of_node;
> > > + struct stm32_dma3_ddata *ddata;
> > > + struct reset_control *reset;
> > > + struct stm32_dma3_chan *chan;
> > > + struct dma_device *dma_dev;
> > > + u32 master_ports, chan_reserved, i, verr;
> > > + u64 hwcfgr;
> > > + int ret;
> > > +
> > > + ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
> > > + if (!ddata)
> > > + return -ENOMEM;
> > > + platform_set_drvdata(pdev, ddata);
> > > +
> > > + dma_dev = &ddata->dma_dev;
> > > +
> > > + ddata->base = devm_platform_ioremap_resource(pdev, 0);
> > > + if (IS_ERR(ddata->base))
> > > + return PTR_ERR(ddata->base);
> > > +
> > > + ddata->clk = devm_clk_get(&pdev->dev, NULL);
> > > + if (IS_ERR(ddata->clk))
> > > + return dev_err_probe(&pdev->dev, PTR_ERR(ddata->clk), "Failed
> > > to get clk\n");
> > > +
> > > + reset = devm_reset_control_get_optional(&pdev->dev, NULL);
> > > + if (IS_ERR(reset))
> > > + return dev_err_probe(&pdev->dev, PTR_ERR(reset), "Failed to get
> > > reset\n");
> > > +
> > > + ret = clk_prepare_enable(ddata->clk);
> > > + if (ret)
> > > + return dev_err_probe(&pdev->dev, ret, "Failed to enable clk\n");
> > > +
> > > + reset_control_reset(reset);
> > > +
> > > + INIT_LIST_HEAD(&dma_dev->channels);
> > > +
> > > + dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
> > > + dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
> > > + dma_dev->dev = &pdev->dev;
> > > + /*
> > > + * This controller supports up to 8-byte buswidth depending on the port
> > > used and the
> > > + * channel, and can only access address at even boundaries, multiple of
> > > the buswidth.
> > > + */
> > > + dma_dev->copy_align = DMAENGINE_ALIGN_8_BYTES;
> > > + dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
> > > + BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
> > > + dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
> > > BIT(DMA_MEM_TO_MEM);
> > > +
> > > + dma_dev->descriptor_reuse = true;
> > > + dma_dev->max_sg_burst = STM32_DMA3_MAX_SEG_SIZE;
> > > + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
> > > + dma_dev->device_alloc_chan_resources = stm32_dma3_alloc_chan_resources;
> > > + dma_dev->device_free_chan_resources = stm32_dma3_free_chan_resources;
> > > + dma_dev->device_prep_slave_sg = stm32_dma3_prep_slave_sg;
> > > + dma_dev->device_caps = stm32_dma3_caps;
> > > + dma_dev->device_config = stm32_dma3_config;
> > > + dma_dev->device_terminate_all = stm32_dma3_terminate_all;
> > > + dma_dev->device_synchronize = stm32_dma3_synchronize;
> > > + dma_dev->device_tx_status = dma_cookie_status;
> > > + dma_dev->device_issue_pending = stm32_dma3_issue_pending;
> > > +
> > > + /* if dma_channels is not modified, get it from hwcfgr1 */
> > > + if (of_property_read_u32(np, "dma-channels", &ddata->dma_channels)) {
> > > + hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
> > > + ddata->dma_channels = FIELD_GET(G_NUM_CHANNELS, hwcfgr);
> > > + }
> > > +
> > > + /* if dma_requests is not modified, get it from hwcfgr2 */
> > > + if (of_property_read_u32(np, "dma-requests", &ddata->dma_requests)) {
> > > + hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR2);
> > > + ddata->dma_requests = FIELD_GET(G_MAX_REQ_ID, hwcfgr) + 1;
> > > + }
> > > +
> > > + /* G_MASTER_PORTS, G_M0_DATA_WIDTH_ENC, G_M1_DATA_WIDTH_ENC in HWCFGR1
> > > */
> > > + hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
> > > + master_ports = FIELD_GET(G_MASTER_PORTS, hwcfgr);
> > > +
> > > + ddata->ports_max_dw[0] = FIELD_GET(G_M0_DATA_WIDTH_ENC, hwcfgr);
> > > + if (master_ports == AXI64 || master_ports == AHB32) /* Single master
> > > port */
> > > + ddata->ports_max_dw[1] = DW_INVALID;
> > > + else /* Dual master ports */
> > > + ddata->ports_max_dw[1] = FIELD_GET(G_M1_DATA_WIDTH_ENC, hwcfgr);
> > > +
> > > + ddata->chans = devm_kcalloc(&pdev->dev, ddata->dma_channels,
> > > sizeof(*ddata->chans),
> > > + GFP_KERNEL);
> > > + if (!ddata->chans) {
> > > + ret = -ENOMEM;
> > > + goto err_clk_disable;
> > > + }
> > > +
> > > + chan_reserved = stm32_dma3_check_rif(ddata);
> > > +
> > > + if (chan_reserved == GENMASK(ddata->dma_channels - 1, 0)) {
> > > + ret = -ENODEV;
> > > + dev_err_probe(&pdev->dev, ret, "No channel available, abort
> > > registration\n");
> > > + goto err_clk_disable;
> > > + }
> > > +
> > > + /* G_FIFO_SIZE x=0..7 in HWCFGR3 and G_FIFO_SIZE x=8..15 in HWCFGR4 */
> > > + hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR3);
> > > + hwcfgr |= ((u64)readl_relaxed(ddata->base + STM32_DMA3_HWCFGR4)) << 32;
> > > +
> > > + for (i = 0; i < ddata->dma_channels; i++) {
> > > + if (chan_reserved & BIT(i))
> > > + continue;
> > > +
> > > + chan = &ddata->chans[i];
> > > + chan->id = i;
> > > + chan->fifo_size = get_chan_hwcfg(i, G_FIFO_SIZE(i), hwcfgr);
> > > + /* If chan->fifo_size > 0 then half of the fifo size, else no
> > > burst when no FIFO */
> > > + chan->max_burst = (chan->fifo_size) ? (1 << (chan->fifo_size +
> > > 1)) / 2 : 0;
> > > + chan->vchan.desc_free = stm32_dma3_chan_vdesc_free;
> > > +
> > > + vchan_init(&chan->vchan, dma_dev);
> > > + }
> > > +
> > > + ret = dmaenginem_async_device_register(dma_dev);
> > > + if (ret)
> > > + goto err_clk_disable;
> > > +
> > > + for (i = 0; i < ddata->dma_channels; i++) {
> > > + if (chan_reserved & BIT(i))
> > > + continue;
> > > +
> > > + ret = platform_get_irq(pdev, i);
> > > + if (ret < 0)
> > > + goto err_clk_disable;
> > > +
> > > + chan = &ddata->chans[i];
> > > + chan->irq = ret;
> > > +
> > > + ret = devm_request_irq(&pdev->dev, chan->irq,
> > > stm32_dma3_chan_irq, 0,
> > > + dev_name(chan2dev(chan)), chan);
> > > + if (ret) {
> > > + dev_err_probe(&pdev->dev, ret, "Failed to request
> > > channel %s IRQ\n",
> > > + dev_name(chan2dev(chan)));
> > > + goto err_clk_disable;
> > > + }
> > > + }
> > > +
> > > + ret = of_dma_controller_register(np, stm32_dma3_of_xlate, ddata);
> > > + if (ret) {
> > > + dev_err_probe(&pdev->dev, ret, "Failed to register
> > > controller\n");
> > > + goto err_clk_disable;
> > > + }
> > > +
> > > + verr = readl_relaxed(ddata->base + STM32_DMA3_VERR);
> > > +
> > > + pm_runtime_set_active(&pdev->dev);
> > > + pm_runtime_enable(&pdev->dev);
> > > + pm_runtime_get_noresume(&pdev->dev);
> > > + pm_runtime_put(&pdev->dev);
> > > +
> > > + dev_info(&pdev->dev, "STM32 DMA3 registered rev:%lu.%lu\n",
> > > + FIELD_GET(VERR_MAJREV, verr), FIELD_GET(VERR_MINREV, verr));
> > > +
> > > + return 0;
> > > +
> > > +err_clk_disable:
> > > + clk_disable_unprepare(ddata->clk);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static void stm32_dma3_remove(struct platform_device *pdev)
> > > +{
> > > + pm_runtime_disable(&pdev->dev);
> > > +}
> > > +
> > > +static int stm32_dma3_runtime_suspend(struct device *dev)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
> > > +
> > > + clk_disable_unprepare(ddata->clk);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int stm32_dma3_runtime_resume(struct device *dev)
> > > +{
> > > + struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
> > > + int ret;
> > > +
> > > + ret = clk_prepare_enable(ddata->clk);
> > > + if (ret)
> > > + dev_err(dev, "Failed to enable clk: %d\n", ret);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static const struct dev_pm_ops stm32_dma3_pm_ops = {
> > > + SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
> > > + RUNTIME_PM_OPS(stm32_dma3_runtime_suspend, stm32_dma3_runtime_resume,
> > > NULL)
> > > +};
> > > +
> > > +static struct platform_driver stm32_dma3_driver = {
> > > + .probe = stm32_dma3_probe,
> > > + .remove_new = stm32_dma3_remove,
> > > + .driver = {
> > > + .name = "stm32-dma3",
> > > + .of_match_table = stm32_dma3_of_match,
> > > + .pm = pm_ptr(&stm32_dma3_pm_ops),
> > > + },
> > > +};
> > > +
> > > +static int __init stm32_dma3_init(void)
> > > +{
> > > + return platform_driver_register(&stm32_dma3_driver);
> > > +}
> > > +
> > > +subsys_initcall(stm32_dma3_init);
> > > +
> > > +MODULE_DESCRIPTION("STM32 DMA3 controller driver");
> > > +MODULE_AUTHOR("Amelie Delaunay <amelie.delau...@foss.st.com>");
> > > +MODULE_LICENSE("GPL");
> > > --
> > > 2.25.1
> > >
