// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2015 Robert Jarzmik */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "dmaengine.h" #include "virt-dma.h" #define DCSR(n) (0x0000 + ((n) << 2)) #define DALGN(n) 0x00a0 #define DINT 0x00f0 #define DDADR(n) (0x0200 + ((n) << 4)) #define DSADR(n) (0x0204 + ((n) << 4)) #define DTADR(n) (0x0208 + ((n) << 4)) #define DCMD(n) (0x020c + ((n) << 4)) #define PXA_DCSR_RUN BIT(31) /* Run Bit (read / write) */ #define PXA_DCSR_NODESC BIT(30) /* No-Descriptor Fetch (read / write) */ #define PXA_DCSR_STOPIRQEN BIT(29) /* Stop Interrupt Enable (R/W) */ #define PXA_DCSR_REQPEND BIT(8) /* Request Pending (read-only) */ #define PXA_DCSR_STOPSTATE BIT(3) /* Stop State (read-only) */ #define PXA_DCSR_ENDINTR BIT(2) /* End Interrupt (read / write) */ #define PXA_DCSR_STARTINTR BIT(1) /* Start Interrupt (read / write) */ #define PXA_DCSR_BUSERR BIT(0) /* Bus Error Interrupt (read / write) */ #define PXA_DCSR_EORIRQEN BIT(28) /* End of Receive IRQ Enable (R/W) */ #define PXA_DCSR_EORJMPEN BIT(27) /* Jump to next descriptor on EOR */ #define PXA_DCSR_EORSTOPEN BIT(26) /* STOP on an EOR */ #define PXA_DCSR_SETCMPST BIT(25) /* Set Descriptor Compare Status */ #define PXA_DCSR_CLRCMPST BIT(24) /* Clear Descriptor Compare Status */ #define PXA_DCSR_CMPST BIT(10) /* The Descriptor Compare Status */ #define PXA_DCSR_EORINTR BIT(9) /* The end of Receive */ #define DRCMR_MAPVLD BIT(7) /* Map Valid (read / write) */ #define DRCMR_CHLNUM 0x1f /* mask for Channel Number (read / write) */ #define DDADR_DESCADDR 0xfffffff0 /* Address of next descriptor (mask) */ #define DDADR_STOP BIT(0) /* Stop (read / write) */ #define PXA_DCMD_INCSRCADDR BIT(31) /* Source Address Increment Setting. */ #define PXA_DCMD_INCTRGADDR BIT(30) /* Target Address Increment Setting. */ #define PXA_DCMD_FLOWSRC BIT(29) /* Flow Control by the source. */ #define PXA_DCMD_FLOWTRG BIT(28) /* Flow Control by the target. */ #define PXA_DCMD_STARTIRQEN BIT(22) /* Start Interrupt Enable */ #define PXA_DCMD_ENDIRQEN BIT(21) /* End Interrupt Enable */ #define PXA_DCMD_ENDIAN BIT(18) /* Device Endian-ness. */ #define PXA_DCMD_BURST8 (1 << 16) /* 8 byte burst */ #define PXA_DCMD_BURST16 (2 << 16) /* 16 byte burst */ #define PXA_DCMD_BURST32 (3 << 16) /* 32 byte burst */ #define PXA_DCMD_WIDTH1 (1 << 14) /* 1 byte width */ #define PXA_DCMD_WIDTH2 (2 << 14) /* 2 byte width (HalfWord) */ #define PXA_DCMD_WIDTH4 (3 << 14) /* 4 byte width (Word) */ #define PXA_DCMD_LENGTH 0x01fff /* length mask (max = 8K - 1) */ #define PDMA_ALIGNMENT 3 #define PDMA_MAX_DESC_BYTES (PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1)) struct pxad_desc_hw { u32 ddadr; /* Points to the next descriptor + flags */ u32 dsadr; /* DSADR value for the current transfer */ u32 dtadr; /* DTADR value for the current transfer */ u32 dcmd; /* DCMD value for the current transfer */ } __aligned(16); struct pxad_desc_sw { struct virt_dma_desc vd; /* Virtual descriptor */ int nb_desc; /* Number of hw. descriptors */ size_t len; /* Number of bytes xfered */ dma_addr_t first; /* First descriptor's addr */ /* At least one descriptor has an src/dst address not multiple of 8 */ bool misaligned; bool cyclic; struct dma_pool *desc_pool; /* Channel's used allocator */ struct pxad_desc_hw *hw_desc[] __counted_by(nb_desc); /* DMA coherent descriptors */ }; struct pxad_phy { int idx; void __iomem *base; struct pxad_chan *vchan; }; struct pxad_chan { struct virt_dma_chan vc; /* Virtual channel */ u32 drcmr; /* Requestor of the channel */ enum pxad_chan_prio prio; /* Required priority of phy */ /* * At least one desc_sw in submitted or issued transfers on this channel * has one address such as: addr % 8 != 0. This implies the DALGN * setting on the phy. */ bool misaligned; struct dma_slave_config cfg; /* Runtime config */ /* protected by vc->lock */ struct pxad_phy *phy; struct dma_pool *desc_pool; /* Descriptors pool */ dma_cookie_t bus_error; wait_queue_head_t wq_state; }; struct pxad_device { struct dma_device slave; int nr_chans; int nr_requestors; void __iomem *base; struct pxad_phy *phys; spinlock_t phy_lock; /* Phy association */ #ifdef CONFIG_DEBUG_FS struct dentry *dbgfs_root; struct dentry **dbgfs_chan; #endif }; #define tx_to_pxad_desc(tx) \ container_of(tx, struct pxad_desc_sw, async_tx) #define to_pxad_chan(dchan) \ container_of(dchan, struct pxad_chan, vc.chan) #define to_pxad_dev(dmadev) \ container_of(dmadev, struct pxad_device, slave) #define to_pxad_sw_desc(_vd) \ container_of((_vd), struct pxad_desc_sw, vd) #define _phy_readl_relaxed(phy, _reg) \ readl_relaxed((phy)->base + _reg((phy)->idx)) #define phy_readl_relaxed(phy, _reg) \ ({ \ u32 _v; \ _v = readl_relaxed((phy)->base + _reg((phy)->idx)); \ dev_vdbg(&phy->vchan->vc.chan.dev->device, \ "%s(): readl(%s): 0x%08x\n", __func__, #_reg, \ _v); \ _v; \ }) #define phy_writel(phy, val, _reg) \ do { \ writel((val), (phy)->base + _reg((phy)->idx)); \ dev_vdbg(&phy->vchan->vc.chan.dev->device, \ "%s(): writel(0x%08x, %s)\n", \ __func__, (u32)(val), #_reg); \ } while (0) #define phy_writel_relaxed(phy, val, _reg) \ do { \ writel_relaxed((val), (phy)->base + _reg((phy)->idx)); \ dev_vdbg(&phy->vchan->vc.chan.dev->device, \ "%s(): writel_relaxed(0x%08x, %s)\n", \ __func__, (u32)(val), #_reg); \ } while (0) static unsigned int pxad_drcmr(unsigned int line) { if (line < 64) return 0x100 + line * 4; return 0x1000 + line * 4; } static bool pxad_filter_fn(struct dma_chan *chan, void *param); /* * Debug fs */ #ifdef CONFIG_DEBUG_FS #include #include #include static int requester_chan_show(struct seq_file *s, void *p) { struct pxad_phy *phy = s->private; int i; u32 drcmr; seq_printf(s, "DMA channel %d requester :\n", phy->idx); for (i = 0; i < 70; i++) { drcmr = readl_relaxed(phy->base + pxad_drcmr(i)); if ((drcmr & DRCMR_CHLNUM) == phy->idx) seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i, !!(drcmr & DRCMR_MAPVLD)); } return 0; } static inline int dbg_burst_from_dcmd(u32 dcmd) { int burst = (dcmd >> 16) & 0x3; return burst ? 4 << burst : 0; } static int is_phys_valid(unsigned long addr) { return pfn_valid(__phys_to_pfn(addr)); } #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "") #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "") static int descriptors_show(struct seq_file *s, void *p) { struct pxad_phy *phy = s->private; int i, max_show = 20, burst, width; u32 dcmd; unsigned long phys_desc, ddadr; struct pxad_desc_hw *desc; phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR); seq_printf(s, "DMA channel %d descriptors :\n", phy->idx); seq_printf(s, "[%03d] First descriptor unknown\n", 0); for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) { desc = phys_to_virt(phys_desc); dcmd = desc->dcmd; burst = dbg_burst_from_dcmd(dcmd); width = (1 << ((dcmd >> 14) & 0x3)) >> 1; seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n", i, phys_desc, desc); seq_printf(s, "\tDDADR = %08x\n", desc->ddadr); seq_printf(s, "\tDSADR = %08x\n", desc->dsadr); seq_printf(s, "\tDTADR = %08x\n", desc->dtadr); seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n", dcmd, PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR), PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG), PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN), PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH); phys_desc = desc->ddadr; } if (i == max_show) seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n", i, phys_desc); else seq_printf(s, "[%03d] Desc at %08lx is %s\n", i, phys_desc, phys_desc == DDADR_STOP ? "DDADR_STOP" : "invalid"); return 0; } static int chan_state_show(struct seq_file *s, void *p) { struct pxad_phy *phy = s->private; u32 dcsr, dcmd; int burst, width; static const char * const str_prio[] = { "high", "normal", "low", "invalid" }; dcsr = _phy_readl_relaxed(phy, DCSR); dcmd = _phy_readl_relaxed(phy, DCMD); burst = dbg_burst_from_dcmd(dcmd); width = (1 << ((dcmd >> 14) & 0x3)) >> 1; seq_printf(s, "DMA channel %d\n", phy->idx); seq_printf(s, "\tPriority : %s\n", str_prio[(phy->idx & 0xf) / 4]); seq_printf(s, "\tUnaligned transfer bit: %s\n", _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ? "yes" : "no"); seq_printf(s, "\tDCSR = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n", dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC), PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN), PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN), PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST), PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR), PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE), PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR), PXA_DCSR_STR(BUSERR)); seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n", dcmd, PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR), PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG), PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN), PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH); seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR)); seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR)); seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR)); return 0; } static int state_show(struct seq_file *s, void *p) { struct pxad_device *pdev = s->private; /* basic device status */ seq_puts(s, "DMA engine status\n"); seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans); return 0; } DEFINE_SHOW_ATTRIBUTE(state); DEFINE_SHOW_ATTRIBUTE(chan_state); DEFINE_SHOW_ATTRIBUTE(descriptors); DEFINE_SHOW_ATTRIBUTE(requester_chan); static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev, int ch, struct dentry *chandir) { char chan_name[11]; struct dentry *chan; void *dt; scnprintf(chan_name, sizeof(chan_name), "%d", ch); chan = debugfs_create_dir(chan_name, chandir); dt = (void *)&pdev->phys[ch]; debugfs_create_file("state", 0400, chan, dt, &chan_state_fops); debugfs_create_file("descriptors", 0400, chan, dt, &descriptors_fops); debugfs_create_file("requesters", 0400, chan, dt, &requester_chan_fops); return chan; } static void pxad_init_debugfs(struct pxad_device *pdev) { int i; struct dentry *chandir; pdev->dbgfs_chan = kmalloc_array(pdev->nr_chans, sizeof(struct dentry *), GFP_KERNEL); if (!pdev->dbgfs_chan) return; pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL); debugfs_create_file("state", 0400, pdev->dbgfs_root, pdev, &state_fops); chandir = debugfs_create_dir("channels", pdev->dbgfs_root); for (i = 0; i < pdev->nr_chans; i++) pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir); } static void pxad_cleanup_debugfs(struct pxad_device *pdev) { debugfs_remove_recursive(pdev->dbgfs_root); } #else static inline void pxad_init_debugfs(struct pxad_device *pdev) {} static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {} #endif static struct pxad_phy *lookup_phy(struct pxad_chan *pchan) { int prio, i; struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device); struct pxad_phy *phy, *found = NULL; unsigned long flags; /* * dma channel priorities * ch 0 - 3, 16 - 19 <--> (0) * ch 4 - 7, 20 - 23 <--> (1) * ch 8 - 11, 24 - 27 <--> (2) * ch 12 - 15, 28 - 31 <--> (3) */ spin_lock_irqsave(&pdev->phy_lock, flags); for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) { for (i = 0; i < pdev->nr_chans; i++) { if (prio != (i & 0xf) >> 2) continue; phy = &pdev->phys[i]; if (!phy->vchan) { phy->vchan = pchan; found = phy; goto out_unlock; } } } out_unlock: spin_unlock_irqrestore(&pdev->phy_lock, flags); dev_dbg(&pchan->vc.chan.dev->device, "%s(): phy=%p(%d)\n", __func__, found, found ? found->idx : -1); return found; } static void pxad_free_phy(struct pxad_chan *chan) { struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); unsigned long flags; u32 reg; dev_dbg(&chan->vc.chan.dev->device, "%s(): freeing\n", __func__); if (!chan->phy) return; /* clear the channel mapping in DRCMR */ if (chan->drcmr <= pdev->nr_requestors) { reg = pxad_drcmr(chan->drcmr); writel_relaxed(0, chan->phy->base + reg); } spin_lock_irqsave(&pdev->phy_lock, flags); chan->phy->vchan = NULL; chan->phy = NULL; spin_unlock_irqrestore(&pdev->phy_lock, flags); } static bool is_chan_running(struct pxad_chan *chan) { u32 dcsr; struct pxad_phy *phy = chan->phy; if (!phy) return false; dcsr = phy_readl_relaxed(phy, DCSR); return dcsr & PXA_DCSR_RUN; } static bool is_running_chan_misaligned(struct pxad_chan *chan) { u32 dalgn; BUG_ON(!chan->phy); dalgn = phy_readl_relaxed(chan->phy, DALGN); return dalgn & (BIT(chan->phy->idx)); } static void phy_enable(struct pxad_phy *phy, bool misaligned) { struct pxad_device *pdev; u32 reg, dalgn; if (!phy->vchan) return; dev_dbg(&phy->vchan->vc.chan.dev->device, "%s(); phy=%p(%d) misaligned=%d\n", __func__, phy, phy->idx, misaligned); pdev = to_pxad_dev(phy->vchan->vc.chan.device); if (phy->vchan->drcmr <= pdev->nr_requestors) { reg = pxad_drcmr(phy->vchan->drcmr); writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg); } dalgn = phy_readl_relaxed(phy, DALGN); if (misaligned) dalgn |= BIT(phy->idx); else dalgn &= ~BIT(phy->idx); phy_writel_relaxed(phy, dalgn, DALGN); phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR | PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR); } static void phy_disable(struct pxad_phy *phy) { u32 dcsr; if (!phy) return; dcsr = phy_readl_relaxed(phy, DCSR); dev_dbg(&phy->vchan->vc.chan.dev->device, "%s(): phy=%p(%d)\n", __func__, phy, phy->idx); phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR); } static void pxad_launch_chan(struct pxad_chan *chan, struct pxad_desc_sw *desc) { dev_dbg(&chan->vc.chan.dev->device, "%s(): desc=%p\n", __func__, desc); if (!chan->phy) { chan->phy = lookup_phy(chan); if (!chan->phy) { dev_dbg(&chan->vc.chan.dev->device, "%s(): no free dma channel\n", __func__); return; } } chan->bus_error = 0; /* * Program the descriptor's address into the DMA controller, * then start the DMA transaction */ phy_writel(chan->phy, desc->first, DDADR); phy_enable(chan->phy, chan->misaligned); wake_up(&chan->wq_state); } static void set_updater_desc(struct pxad_desc_sw *sw_desc, unsigned long flags) { struct pxad_desc_hw *updater = sw_desc->hw_desc[sw_desc->nb_desc - 1]; dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr; updater->ddadr = DDADR_STOP; updater->dsadr = dma; updater->dtadr = dma + 8; updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 | (PXA_DCMD_LENGTH & sizeof(u32)); if (flags & DMA_PREP_INTERRUPT) updater->dcmd |= PXA_DCMD_ENDIRQEN; if (sw_desc->cyclic) sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first; } static bool is_desc_completed(struct virt_dma_desc *vd) { struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd); struct pxad_desc_hw *updater = sw_desc->hw_desc[sw_desc->nb_desc - 1]; return updater->dtadr != (updater->dsadr + 8); } static void pxad_desc_chain(struct virt_dma_desc *vd1, struct virt_dma_desc *vd2) { struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1); struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2); dma_addr_t dma_to_chain; dma_to_chain = desc2->first; desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain; } static bool pxad_try_hotchain(struct virt_dma_chan *vc, struct virt_dma_desc *vd) { struct virt_dma_desc *vd_last_issued = NULL; struct pxad_chan *chan = to_pxad_chan(&vc->chan); /* * Attempt to hot chain the tx if the phy is still running. This is * considered successful only if either the channel is still running * after the chaining, or if the chained transfer is completed after * having been hot chained. * A change of alignment is not allowed, and forbids hotchaining. */ if (is_chan_running(chan)) { BUG_ON(list_empty(&vc->desc_issued)); if (!is_running_chan_misaligned(chan) && to_pxad_sw_desc(vd)->misaligned) return false; vd_last_issued = list_entry(vc->desc_issued.prev, struct virt_dma_desc, node); pxad_desc_chain(vd_last_issued, vd); if (is_chan_running(chan) || is_desc_completed(vd)) return true; } return false; } static unsigned int clear_chan_irq(struct pxad_phy *phy) { u32 dcsr; u32 dint = readl(phy->base + DINT); if (!(dint & BIT(phy->idx))) return PXA_DCSR_RUN; /* clear irq */ dcsr = phy_readl_relaxed(phy, DCSR); phy_writel(phy, dcsr, DCSR); if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan)) dev_warn(&phy->vchan->vc.chan.dev->device, "%s(chan=%p): PXA_DCSR_BUSERR\n", __func__, &phy->vchan); return dcsr & ~PXA_DCSR_RUN; } static irqreturn_t pxad_chan_handler(int irq, void *dev_id) { struct pxad_phy *phy = dev_id; struct pxad_chan *chan = phy->vchan; struct virt_dma_desc *vd, *tmp; unsigned int dcsr; bool vd_completed; dma_cookie_t last_started = 0; BUG_ON(!chan); dcsr = clear_chan_irq(phy); if (dcsr & PXA_DCSR_RUN) return IRQ_NONE; spin_lock(&chan->vc.lock); list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) { vd_completed = is_desc_completed(vd); dev_dbg(&chan->vc.chan.dev->device, "%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n", __func__, vd, vd->tx.cookie, vd_completed, dcsr); last_started = vd->tx.cookie; if (to_pxad_sw_desc(vd)->cyclic) { vchan_cyclic_callback(vd); break; } if (vd_completed) { list_del(&vd->node); vchan_cookie_complete(vd); } else { break; } } if (dcsr & PXA_DCSR_BUSERR) { chan->bus_error = last_started; phy_disable(phy); } if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) { dev_dbg(&chan->vc.chan.dev->device, "%s(): channel stopped, submitted_empty=%d issued_empty=%d", __func__, list_empty(&chan->vc.desc_submitted), list_empty(&chan->vc.desc_issued)); phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR); if (list_empty(&chan->vc.desc_issued)) { chan->misaligned = !list_empty(&chan->vc.desc_submitted); } else { vd = list_first_entry(&chan->vc.desc_issued, struct virt_dma_desc, node); pxad_launch_chan(chan, to_pxad_sw_desc(vd)); } } spin_unlock(&chan->vc.lock); wake_up(&chan->wq_state); return IRQ_HANDLED; } static irqreturn_t pxad_int_handler(int irq, void *dev_id) { struct pxad_device *pdev = dev_id; struct pxad_phy *phy; u32 dint = readl(pdev->base + DINT); int i, ret = IRQ_NONE; while (dint) { i = __ffs(dint); dint &= (dint - 1); phy = &pdev->phys[i]; if (pxad_chan_handler(irq, phy) == IRQ_HANDLED) ret = IRQ_HANDLED; } return ret; } static int pxad_alloc_chan_resources(struct dma_chan *dchan) { struct pxad_chan *chan = to_pxad_chan(dchan); struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); if (chan->desc_pool) return 1; chan->desc_pool = dma_pool_create(dma_chan_name(dchan), pdev->slave.dev, sizeof(struct pxad_desc_hw), __alignof__(struct pxad_desc_hw), 0); if (!chan->desc_pool) { dev_err(&chan->vc.chan.dev->device, "%s(): unable to allocate descriptor pool\n", __func__); return -ENOMEM; } return 1; } static void pxad_free_chan_resources(struct dma_chan *dchan) { struct pxad_chan *chan = to_pxad_chan(dchan); vchan_free_chan_resources(&chan->vc); dma_pool_destroy(chan->desc_pool); chan->desc_pool = NULL; chan->drcmr = U32_MAX; chan->prio = PXAD_PRIO_LOWEST; } static void pxad_free_desc(struct virt_dma_desc *vd) { int i; dma_addr_t dma; struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd); for (i = sw_desc->nb_desc - 1; i >= 0; i--) { if (i > 0) dma = sw_desc->hw_desc[i - 1]->ddadr; else dma = sw_desc->first; dma_pool_free(sw_desc->desc_pool, sw_desc->hw_desc[i], dma); } sw_desc->nb_desc = 0; kfree(sw_desc); } static struct pxad_desc_sw * pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc) { struct pxad_desc_sw *sw_desc; dma_addr_t dma; void *desc; int i; sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc), GFP_NOWAIT); if (!sw_desc) return NULL; sw_desc->desc_pool = chan->desc_pool; for (i = 0; i < nb_hw_desc; i++) { desc = dma_pool_alloc(sw_desc->desc_pool, GFP_NOWAIT, &dma); if (!desc) { dev_err(&chan->vc.chan.dev->device, "%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n", __func__, i, sw_desc->desc_pool); goto err; } sw_desc->nb_desc++; sw_desc->hw_desc[i] = desc; if (i == 0) sw_desc->first = dma; else sw_desc->hw_desc[i - 1]->ddadr = dma; } return sw_desc; err: pxad_free_desc(&sw_desc->vd); return NULL; } static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx) { struct virt_dma_chan *vc = to_virt_chan(tx->chan); struct pxad_chan *chan = to_pxad_chan(&vc->chan); struct virt_dma_desc *vd_chained = NULL, *vd = container_of(tx, struct virt_dma_desc, tx); dma_cookie_t cookie; unsigned long flags; set_updater_desc(to_pxad_sw_desc(vd), tx->flags); spin_lock_irqsave(&vc->lock, flags); cookie = dma_cookie_assign(tx); if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) { list_move_tail(&vd->node, &vc->desc_issued); dev_dbg(&chan->vc.chan.dev->device, "%s(): txd %p[%x]: submitted (hot linked)\n", __func__, vd, cookie); goto out; } /* * Fallback to placing the tx in the submitted queue */ if (!list_empty(&vc->desc_submitted)) { vd_chained = list_entry(vc->desc_submitted.prev, struct virt_dma_desc, node); /* * Only chain the descriptors if no new misalignment is * introduced. If a new misalignment is chained, let the channel * stop, and be relaunched in misalign mode from the irq * handler. */ if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned) pxad_desc_chain(vd_chained, vd); else vd_chained = NULL; } dev_dbg(&chan->vc.chan.dev->device, "%s(): txd %p[%x]: submitted (%s linked)\n", __func__, vd, cookie, vd_chained ? "cold" : "not"); list_move_tail(&vd->node, &vc->desc_submitted); chan->misaligned |= to_pxad_sw_desc(vd)->misaligned; out: spin_unlock_irqrestore(&vc->lock, flags); return cookie; } static void pxad_issue_pending(struct dma_chan *dchan) { struct pxad_chan *chan = to_pxad_chan(dchan); struct virt_dma_desc *vd_first; unsigned long flags; spin_lock_irqsave(&chan->vc.lock, flags); if (list_empty(&chan->vc.desc_submitted)) goto out; vd_first = list_first_entry(&chan->vc.desc_submitted, struct virt_dma_desc, node); dev_dbg(&chan->vc.chan.dev->device, "%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie); vchan_issue_pending(&chan->vc); if (!pxad_try_hotchain(&chan->vc, vd_first)) pxad_launch_chan(chan, to_pxad_sw_desc(vd_first)); out: spin_unlock_irqrestore(&chan->vc.lock, flags); } static inline struct dma_async_tx_descriptor * pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd, unsigned long tx_flags) { struct dma_async_tx_descriptor *tx; struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc); INIT_LIST_HEAD(&vd->node); tx = vchan_tx_prep(vc, vd, tx_flags); tx->tx_submit = pxad_tx_submit; dev_dbg(&chan->vc.chan.dev->device, "%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__, vc, vd, vd->tx.cookie, tx_flags); return tx; } static void pxad_get_config(struct pxad_chan *chan, enum dma_transfer_direction dir, u32 *dcmd, u32 *dev_src, u32 *dev_dst) { u32 maxburst = 0, dev_addr = 0; enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED; struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); *dcmd = 0; if (dir == DMA_DEV_TO_MEM) { maxburst = chan->cfg.src_maxburst; width = chan->cfg.src_addr_width; dev_addr = chan->cfg.src_addr; *dev_src = dev_addr; *dcmd |= PXA_DCMD_INCTRGADDR; if (chan->drcmr <= pdev->nr_requestors) *dcmd |= PXA_DCMD_FLOWSRC; } if (dir == DMA_MEM_TO_DEV) { maxburst = chan->cfg.dst_maxburst; width = chan->cfg.dst_addr_width; dev_addr = chan->cfg.dst_addr; *dev_dst = dev_addr; *dcmd |= PXA_DCMD_INCSRCADDR; if (chan->drcmr <= pdev->nr_requestors) *dcmd |= PXA_DCMD_FLOWTRG; } if (dir == DMA_MEM_TO_MEM) *dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR | PXA_DCMD_INCSRCADDR; dev_dbg(&chan->vc.chan.dev->device, "%s(): dev_addr=0x%x maxburst=%d width=%d dir=%d\n", __func__, dev_addr, maxburst, width, dir); if (width == DMA_SLAVE_BUSWIDTH_1_BYTE) *dcmd |= PXA_DCMD_WIDTH1; else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES) *dcmd |= PXA_DCMD_WIDTH2; else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES) *dcmd |= PXA_DCMD_WIDTH4; if (maxburst == 8) *dcmd |= PXA_DCMD_BURST8; else if (maxburst == 16) *dcmd |= PXA_DCMD_BURST16; else if (maxburst == 32) *dcmd |= PXA_DCMD_BURST32; } static struct dma_async_tx_descriptor * pxad_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src, size_t len, unsigned long flags) { struct pxad_chan *chan = to_pxad_chan(dchan); struct pxad_desc_sw *sw_desc; struct pxad_desc_hw *hw_desc; u32 dcmd; unsigned int i, nb_desc = 0; size_t copy; if (!dchan || !len) return NULL; dev_dbg(&chan->vc.chan.dev->device, "%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n", __func__, (unsigned long)dma_dst, (unsigned long)dma_src, len, flags); pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL); nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES); sw_desc = pxad_alloc_desc(chan, nb_desc + 1); if (!sw_desc) return NULL; sw_desc->len = len; if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) || !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT)) sw_desc->misaligned = true; i = 0; do { hw_desc = sw_desc->hw_desc[i++]; copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES); hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy); hw_desc->dsadr = dma_src; hw_desc->dtadr = dma_dst; len -= copy; dma_src += copy; dma_dst += copy; } while (len); set_updater_desc(sw_desc, flags); return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags); } static struct dma_async_tx_descriptor * pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags, void *context) { struct pxad_chan *chan = to_pxad_chan(dchan); struct pxad_desc_sw *sw_desc; size_t len, avail; struct scatterlist *sg; dma_addr_t dma; u32 dcmd, dsadr = 0, dtadr = 0; unsigned int nb_desc = 0, i, j = 0; if ((sgl == NULL) || (sg_len == 0)) return NULL; pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr); dev_dbg(&chan->vc.chan.dev->device, "%s(): dir=%d flags=%lx\n", __func__, dir, flags); for_each_sg(sgl, sg, sg_len, i) nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES); sw_desc = pxad_alloc_desc(chan, nb_desc + 1); if (!sw_desc) return NULL; for_each_sg(sgl, sg, sg_len, i) { dma = sg_dma_address(sg); avail = sg_dma_len(sg); sw_desc->len += avail; do { len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES); if (dma & 0x7) sw_desc->misaligned = true; sw_desc->hw_desc[j]->dcmd = dcmd | (PXA_DCMD_LENGTH & len); sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma; sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma; dma += len; avail -= len; } while (avail); } set_updater_desc(sw_desc, flags); return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags); } static struct dma_async_tx_descriptor * pxad_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t buf_addr, size_t len, size_t period_len, enum dma_transfer_direction dir, unsigned long flags) { struct pxad_chan *chan = to_pxad_chan(dchan); struct pxad_desc_sw *sw_desc; struct pxad_desc_hw **phw_desc; dma_addr_t dma; u32 dcmd, dsadr = 0, dtadr = 0; unsigned int nb_desc = 0; if (!dchan || !len || !period_len) return NULL; if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) { dev_err(&chan->vc.chan.dev->device, "Unsupported direction for cyclic DMA\n"); return NULL; } /* the buffer length must be a multiple of period_len */ if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES || !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT)) return NULL; pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr); dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len); dev_dbg(&chan->vc.chan.dev->device, "%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n", __func__, (unsigned long)buf_addr, len, period_len, dir, flags); nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES); nb_desc *= DIV_ROUND_UP(len, period_len); sw_desc = pxad_alloc_desc(chan, nb_desc + 1); if (!sw_desc) return NULL; sw_desc->cyclic = true; sw_desc->len = len; phw_desc = sw_desc->hw_desc; dma = buf_addr; do { phw_desc[0]->dsadr = dsadr ? dsadr : dma; phw_desc[0]->dtadr = dtadr ? dtadr : dma; phw_desc[0]->dcmd = dcmd; phw_desc++; dma += period_len; len -= period_len; } while (len); set_updater_desc(sw_desc, flags); return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags); } static int pxad_config(struct dma_chan *dchan, struct dma_slave_config *cfg) { struct pxad_chan *chan = to_pxad_chan(dchan); if (!dchan) return -EINVAL; chan->cfg = *cfg; return 0; } static int pxad_terminate_all(struct dma_chan *dchan) { struct pxad_chan *chan = to_pxad_chan(dchan); struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); struct virt_dma_desc *vd = NULL; unsigned long flags; struct pxad_phy *phy; LIST_HEAD(head); dev_dbg(&chan->vc.chan.dev->device, "%s(): vchan %p: terminate all\n", __func__, &chan->vc); spin_lock_irqsave(&chan->vc.lock, flags); vchan_get_all_descriptors(&chan->vc, &head); list_for_each_entry(vd, &head, node) { dev_dbg(&chan->vc.chan.dev->device, "%s(): cancelling txd %p[%x] (completed=%d)", __func__, vd, vd->tx.cookie, is_desc_completed(vd)); } phy = chan->phy; if (phy) { phy_disable(chan->phy); pxad_free_phy(chan); chan->phy = NULL; spin_lock(&pdev->phy_lock); phy->vchan = NULL; spin_unlock(&pdev->phy_lock); } spin_unlock_irqrestore(&chan->vc.lock, flags); vchan_dma_desc_free_list(&chan->vc, &head); return 0; } static unsigned int pxad_residue(struct pxad_chan *chan, dma_cookie_t cookie) { struct virt_dma_desc *vd = NULL; struct pxad_desc_sw *sw_desc = NULL; struct pxad_desc_hw *hw_desc = NULL; u32 curr, start, len, end, residue = 0; unsigned long flags; bool passed = false; int i; /* * If the channel does not have a phy pointer anymore, it has already * been completed. Therefore, its residue is 0. */ if (!chan->phy) return 0; spin_lock_irqsave(&chan->vc.lock, flags); vd = vchan_find_desc(&chan->vc, cookie); if (!vd) goto out; sw_desc = to_pxad_sw_desc(vd); if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR) curr = phy_readl_relaxed(chan->phy, DSADR); else curr = phy_readl_relaxed(chan->phy, DTADR); /* * curr has to be actually read before checking descriptor * completion, so that a curr inside a status updater * descriptor implies the following test returns true, and * preventing reordering of curr load and the test. */ rmb(); if (is_desc_completed(vd)) goto out; for (i = 0; i < sw_desc->nb_desc - 1; i++) { hw_desc = sw_desc->hw_desc[i]; if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR) start = hw_desc->dsadr; else start = hw_desc->dtadr; len = hw_desc->dcmd & PXA_DCMD_LENGTH; end = start + len; /* * 'passed' will be latched once we found the descriptor * which lies inside the boundaries of the curr * pointer. All descriptors that occur in the list * _after_ we found that partially handled descriptor * are still to be processed and are hence added to the * residual bytes counter. */ if (passed) { residue += len; } else if (curr >= start && curr <= end) { residue += end - curr; passed = true; } } if (!passed) residue = sw_desc->len; out: spin_unlock_irqrestore(&chan->vc.lock, flags); dev_dbg(&chan->vc.chan.dev->device, "%s(): txd %p[%x] sw_desc=%p: %d\n", __func__, vd, cookie, sw_desc, residue); return residue; } static enum dma_status pxad_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct pxad_chan *chan = to_pxad_chan(dchan); enum dma_status ret; if (cookie == chan->bus_error) return DMA_ERROR; ret = dma_cookie_status(dchan, cookie, txstate); if (likely(txstate && (ret != DMA_ERROR))) dma_set_residue(txstate, pxad_residue(chan, cookie)); return ret; } static void pxad_synchronize(struct dma_chan *dchan) { struct pxad_chan *chan = to_pxad_chan(dchan); wait_event(chan->wq_state, !is_chan_running(chan)); vchan_synchronize(&chan->vc); } static void pxad_free_channels(struct dma_device *dmadev) { struct pxad_chan *c, *cn; list_for_each_entry_safe(c, cn, &dmadev->channels, vc.chan.device_node) { list_del(&c->vc.chan.device_node); tasklet_kill(&c->vc.task); } } static void pxad_remove(struct platform_device *op) { struct pxad_device *pdev = platform_get_drvdata(op); pxad_cleanup_debugfs(pdev); pxad_free_channels(&pdev->slave); } static int pxad_init_phys(struct platform_device *op, struct pxad_device *pdev, unsigned int nb_phy_chans) { int irq0, irq, nr_irq = 0, i, ret; struct pxad_phy *phy; irq0 = platform_get_irq(op, 0); if (irq0 < 0) return irq0; pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans, sizeof(pdev->phys[0]), GFP_KERNEL); if (!pdev->phys) return -ENOMEM; for (i = 0; i < nb_phy_chans; i++) if (platform_get_irq_optional(op, i) > 0) nr_irq++; for (i = 0; i < nb_phy_chans; i++) { phy = &pdev->phys[i]; phy->base = pdev->base; phy->idx = i; irq = platform_get_irq_optional(op, i); if ((nr_irq > 1) && (irq > 0)) ret = devm_request_irq(&op->dev, irq, pxad_chan_handler, IRQF_SHARED, "pxa-dma", phy); if ((nr_irq == 1) && (i == 0)) ret = devm_request_irq(&op->dev, irq0, pxad_int_handler, IRQF_SHARED, "pxa-dma", pdev); if (ret) { dev_err(pdev->slave.dev, "%s(): can't request irq %d:%d\n", __func__, irq, ret); return ret; } } return 0; } static const struct of_device_id pxad_dt_ids[] = { { .compatible = "marvell,pdma-1.0", }, {} }; MODULE_DEVICE_TABLE(of, pxad_dt_ids); static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct pxad_device *d = ofdma->of_dma_data; struct dma_chan *chan; chan = dma_get_any_slave_channel(&d->slave); if (!chan) return NULL; to_pxad_chan(chan)->drcmr = dma_spec->args[0]; to_pxad_chan(chan)->prio = dma_spec->args[1]; return chan; } static int pxad_init_dmadev(struct platform_device *op, struct pxad_device *pdev, unsigned int nr_phy_chans, unsigned int nr_requestors) { int ret; unsigned int i; struct pxad_chan *c; pdev->nr_chans = nr_phy_chans; pdev->nr_requestors = nr_requestors; INIT_LIST_HEAD(&pdev->slave.channels); pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources; pdev->slave.device_free_chan_resources = pxad_free_chan_resources; pdev->slave.device_tx_status = pxad_tx_status; pdev->slave.device_issue_pending = pxad_issue_pending; pdev->slave.device_config = pxad_config; pdev->slave.device_synchronize = pxad_synchronize; pdev->slave.device_terminate_all = pxad_terminate_all; if (op->dev.coherent_dma_mask) dma_set_mask(&op->dev, op->dev.coherent_dma_mask); else dma_set_mask(&op->dev, DMA_BIT_MASK(32)); ret = pxad_init_phys(op, pdev, nr_phy_chans); if (ret) return ret; for (i = 0; i < nr_phy_chans; i++) { c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL); if (!c) return -ENOMEM; c->drcmr = U32_MAX; c->prio = PXAD_PRIO_LOWEST; c->vc.desc_free = pxad_free_desc; vchan_init(&c->vc, &pdev->slave); init_waitqueue_head(&c->wq_state); } return dmaenginem_async_device_register(&pdev->slave); } static int pxad_probe(struct platform_device *op) { struct pxad_device *pdev; const struct dma_slave_map *slave_map = NULL; struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev); int ret, dma_channels = 0, nb_requestors = 0, slave_map_cnt = 0; const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES; pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL); if (!pdev) return -ENOMEM; spin_lock_init(&pdev->phy_lock); pdev->base = devm_platform_ioremap_resource(op, 0); if (IS_ERR(pdev->base)) return PTR_ERR(pdev->base); if (op->dev.of_node) { /* Parse new and deprecated dma-channels properties */ if (of_property_read_u32(op->dev.of_node, "dma-channels", &dma_channels)) of_property_read_u32(op->dev.of_node, "#dma-channels", &dma_channels); /* Parse new and deprecated dma-requests properties */ ret = of_property_read_u32(op->dev.of_node, "dma-requests", &nb_requestors); if (ret) ret = of_property_read_u32(op->dev.of_node, "#dma-requests", &nb_requestors); if (ret) { dev_warn(pdev->slave.dev, "#dma-requests set to default 32 as missing in OF: %d", ret); nb_requestors = 32; } } else if (pdata && pdata->dma_channels) { dma_channels = pdata->dma_channels; nb_requestors = pdata->nb_requestors; slave_map = pdata->slave_map; slave_map_cnt = pdata->slave_map_cnt; } else { dma_channels = 32; /* default 32 channel */ } dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask); dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask); dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask); dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask); pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy; pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg; pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic; pdev->slave.filter.map = slave_map; pdev->slave.filter.mapcnt = slave_map_cnt; pdev->slave.filter.fn = pxad_filter_fn; pdev->slave.copy_align = PDMA_ALIGNMENT; pdev->slave.src_addr_widths = widths; pdev->slave.dst_addr_widths = widths; pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; pdev->slave.descriptor_reuse = true; pdev->slave.dev = &op->dev; ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors); if (ret) { dev_err(pdev->slave.dev, "unable to register\n"); return ret; } if (op->dev.of_node) { /* Device-tree DMA controller registration */ ret = of_dma_controller_register(op->dev.of_node, pxad_dma_xlate, pdev); if (ret < 0) { dev_err(pdev->slave.dev, "of_dma_controller_register failed\n"); return ret; } } platform_set_drvdata(op, pdev); pxad_init_debugfs(pdev); dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n", dma_channels, nb_requestors); return 0; } static const struct platform_device_id pxad_id_table[] = { { "pxa-dma", }, { }, }; static struct platform_driver pxad_driver = { .driver = { .name = "pxa-dma", .of_match_table = pxad_dt_ids, }, .id_table = pxad_id_table, .probe = pxad_probe, .remove = pxad_remove, }; static bool pxad_filter_fn(struct dma_chan *chan, void *param) { struct pxad_chan *c = to_pxad_chan(chan); struct pxad_param *p = param; if (chan->device->dev->driver != &pxad_driver.driver) return false; c->drcmr = p->drcmr; c->prio = p->prio; return true; } module_platform_driver(pxad_driver); MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver"); MODULE_AUTHOR("Robert Jarzmik "); MODULE_LICENSE("GPL v2");