| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Laurent Pinchart | 6266 | 80.53% | 10 | 19.23% |
| Kuninori Morimoto | 525 | 6.75% | 11 | 21.15% |
| Niklas Söderlund | 487 | 6.26% | 7 | 13.46% |
| Yoshihiro Shimoda | 258 | 3.32% | 7 | 13.46% |
| Achim Dahlhoff | 76 | 0.98% | 1 | 1.92% |
| Dave Jiang | 41 | 0.53% | 1 | 1.92% |
| Wolfram Sang | 24 | 0.31% | 1 | 1.92% |
| Geert Uytterhoeven | 24 | 0.31% | 5 | 9.62% |
| Dirk Behme | 24 | 0.31% | 1 | 1.92% |
| Jürg Billeter | 22 | 0.28% | 1 | 1.92% |
| Muhammad Hamza Farooq | 17 | 0.22% | 2 | 3.85% |
| Baolin Wang | 6 | 0.08% | 1 | 1.92% |
| Joe Perches | 5 | 0.06% | 1 | 1.92% |
| Joerg Roedel | 4 | 0.05% | 1 | 1.92% |
| Colin Ian King | 1 | 0.01% | 1 | 1.92% |
| Hiroyuki Yokoyama | 1 | 0.01% | 1 | 1.92% |
| Total | 7781 | 52 |
// SPDX-License-Identifier: GPL-2.0 /* * Renesas R-Car Gen2/Gen3 DMA Controller Driver * * Copyright (C) 2014-2019 Renesas Electronics Inc. * * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> */ #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/interrupt.h> #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> #include <linux/of_dma.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/slab.h> #include <linux/spinlock.h> #include "../dmaengine.h" /* * struct rcar_dmac_xfer_chunk - Descriptor for a hardware transfer * @node: entry in the parent's chunks list * @src_addr: device source address * @dst_addr: device destination address * @size: transfer size in bytes */ struct rcar_dmac_xfer_chunk { struct list_head node; dma_addr_t src_addr; dma_addr_t dst_addr; u32 size; }; /* * struct rcar_dmac_hw_desc - Hardware descriptor for a transfer chunk * @sar: value of the SAR register (source address) * @dar: value of the DAR register (destination address) * @tcr: value of the TCR register (transfer count) */ struct rcar_dmac_hw_desc { u32 sar; u32 dar; u32 tcr; u32 reserved; } __attribute__((__packed__)); /* * struct rcar_dmac_desc - R-Car Gen2 DMA Transfer Descriptor * @async_tx: base DMA asynchronous transaction descriptor * @direction: direction of the DMA transfer * @xfer_shift: log2 of the transfer size * @chcr: value of the channel configuration register for this transfer * @node: entry in the channel's descriptors lists * @chunks: list of transfer chunks for this transfer * @running: the transfer chunk being currently processed * @nchunks: number of transfer chunks for this transfer * @hwdescs.use: whether the transfer descriptor uses hardware descriptors * @hwdescs.mem: hardware descriptors memory for the transfer * @hwdescs.dma: device address of the hardware descriptors memory * @hwdescs.size: size of the hardware descriptors in bytes * @size: transfer size in bytes * @cyclic: when set indicates that the DMA transfer is cyclic */ struct rcar_dmac_desc { struct dma_async_tx_descriptor async_tx; enum dma_transfer_direction direction; unsigned int xfer_shift; u32 chcr; struct list_head node; struct list_head chunks; struct rcar_dmac_xfer_chunk *running; unsigned int nchunks; struct { bool use; struct rcar_dmac_hw_desc *mem; dma_addr_t dma; size_t size; } hwdescs; unsigned int size; bool cyclic; }; #define to_rcar_dmac_desc(d) container_of(d, struct rcar_dmac_desc, async_tx) /* * struct rcar_dmac_desc_page - One page worth of descriptors * @node: entry in the channel's pages list * @descs: array of DMA descriptors * @chunks: array of transfer chunk descriptors */ struct rcar_dmac_desc_page { struct list_head node; union { struct rcar_dmac_desc descs[0]; struct rcar_dmac_xfer_chunk chunks[0]; }; }; #define RCAR_DMAC_DESCS_PER_PAGE \ ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, descs)) / \ sizeof(struct rcar_dmac_desc)) #define RCAR_DMAC_XFER_CHUNKS_PER_PAGE \ ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, chunks)) / \ sizeof(struct rcar_dmac_xfer_chunk)) /* * struct rcar_dmac_chan_slave - Slave configuration * @slave_addr: slave memory address * @xfer_size: size (in bytes) of hardware transfers */ struct rcar_dmac_chan_slave { phys_addr_t slave_addr; unsigned int xfer_size; }; /* * struct rcar_dmac_chan_map - Map of slave device phys to dma address * @addr: slave dma address * @dir: direction of mapping * @slave: slave configuration that is mapped */ struct rcar_dmac_chan_map { dma_addr_t addr; enum dma_data_direction dir; struct rcar_dmac_chan_slave slave; }; /* * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel * @chan: base DMA channel object * @iomem: channel I/O memory base * @index: index of this channel in the controller * @irq: channel IRQ * @src: slave memory address and size on the source side * @dst: slave memory address and size on the destination side * @mid_rid: hardware MID/RID for the DMA client using this channel * @lock: protects the channel CHCR register and the desc members * @desc.free: list of free descriptors * @desc.pending: list of pending descriptors (submitted with tx_submit) * @desc.active: list of active descriptors (activated with issue_pending) * @desc.done: list of completed descriptors * @desc.wait: list of descriptors waiting for an ack * @desc.running: the descriptor being processed (a member of the active list) * @desc.chunks_free: list of free transfer chunk descriptors * @desc.pages: list of pages used by allocated descriptors */ struct rcar_dmac_chan { struct dma_chan chan; void __iomem *iomem; unsigned int index; int irq; struct rcar_dmac_chan_slave src; struct rcar_dmac_chan_slave dst; struct rcar_dmac_chan_map map; int mid_rid; spinlock_t lock; struct { struct list_head free; struct list_head pending; struct list_head active; struct list_head done; struct list_head wait; struct rcar_dmac_desc *running; struct list_head chunks_free; struct list_head pages; } desc; }; #define to_rcar_dmac_chan(c) container_of(c, struct rcar_dmac_chan, chan) /* * struct rcar_dmac - R-Car Gen2 DMA Controller * @engine: base DMA engine object * @dev: the hardware device * @iomem: remapped I/O memory base * @n_channels: number of available channels * @channels: array of DMAC channels * @channels_mask: bitfield of which DMA channels are managed by this driver * @modules: bitmask of client modules in use */ struct rcar_dmac { struct dma_device engine; struct device *dev; void __iomem *iomem; struct device_dma_parameters parms; unsigned int n_channels; struct rcar_dmac_chan *channels; u32 channels_mask; DECLARE_BITMAP(modules, 256); }; #define to_rcar_dmac(d) container_of(d, struct rcar_dmac, engine) /* * struct rcar_dmac_of_data - This driver's OF data * @chan_offset_base: DMAC channels base offset * @chan_offset_stride: DMAC channels offset stride */ struct rcar_dmac_of_data { u32 chan_offset_base; u32 chan_offset_stride; }; /* ----------------------------------------------------------------------------- * Registers */ #define RCAR_DMAISTA 0x0020 #define RCAR_DMASEC 0x0030 #define RCAR_DMAOR 0x0060 #define RCAR_DMAOR_PRI_FIXED (0 << 8) #define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8) #define RCAR_DMAOR_AE (1 << 2) #define RCAR_DMAOR_DME (1 << 0) #define RCAR_DMACHCLR 0x0080 #define RCAR_DMADPSEC 0x00a0 #define RCAR_DMASAR 0x0000 #define RCAR_DMADAR 0x0004 #define RCAR_DMATCR 0x0008 #define RCAR_DMATCR_MASK 0x00ffffff #define RCAR_DMATSR 0x0028 #define RCAR_DMACHCR 0x000c #define RCAR_DMACHCR_CAE (1 << 31) #define RCAR_DMACHCR_CAIE (1 << 30) #define RCAR_DMACHCR_DPM_DISABLED (0 << 28) #define RCAR_DMACHCR_DPM_ENABLED (1 << 28) #define RCAR_DMACHCR_DPM_REPEAT (2 << 28) #define RCAR_DMACHCR_DPM_INFINITE (3 << 28) #define RCAR_DMACHCR_RPT_SAR (1 << 27) #define RCAR_DMACHCR_RPT_DAR (1 << 26) #define RCAR_DMACHCR_RPT_TCR (1 << 25) #define RCAR_DMACHCR_DPB (1 << 22) #define RCAR_DMACHCR_DSE (1 << 19) #define RCAR_DMACHCR_DSIE (1 << 18) #define RCAR_DMACHCR_TS_1B ((0 << 20) | (0 << 3)) #define RCAR_DMACHCR_TS_2B ((0 << 20) | (1 << 3)) #define RCAR_DMACHCR_TS_4B ((0 << 20) | (2 << 3)) #define RCAR_DMACHCR_TS_16B ((0 << 20) | (3 << 3)) #define RCAR_DMACHCR_TS_32B ((1 << 20) | (0 << 3)) #define RCAR_DMACHCR_TS_64B ((1 << 20) | (1 << 3)) #define RCAR_DMACHCR_TS_8B ((1 << 20) | (3 << 3)) #define RCAR_DMACHCR_DM_FIXED (0 << 14) #define RCAR_DMACHCR_DM_INC (1 << 14) #define RCAR_DMACHCR_DM_DEC (2 << 14) #define RCAR_DMACHCR_SM_FIXED (0 << 12) #define RCAR_DMACHCR_SM_INC (1 << 12) #define RCAR_DMACHCR_SM_DEC (2 << 12) #define RCAR_DMACHCR_RS_AUTO (4 << 8) #define RCAR_DMACHCR_RS_DMARS (8 << 8) #define RCAR_DMACHCR_IE (1 << 2) #define RCAR_DMACHCR_TE (1 << 1) #define RCAR_DMACHCR_DE (1 << 0) #define RCAR_DMATCRB 0x0018 #define RCAR_DMATSRB 0x0038 #define RCAR_DMACHCRB 0x001c #define RCAR_DMACHCRB_DCNT(n) ((n) << 24) #define RCAR_DMACHCRB_DPTR_MASK (0xff << 16) #define RCAR_DMACHCRB_DPTR_SHIFT 16 #define RCAR_DMACHCRB_DRST (1 << 15) #define RCAR_DMACHCRB_DTS (1 << 8) #define RCAR_DMACHCRB_SLM_NORMAL (0 << 4) #define RCAR_DMACHCRB_SLM_CLK(n) ((8 | (n)) << 4) #define RCAR_DMACHCRB_PRI(n) ((n) << 0) #define RCAR_DMARS 0x0040 #define RCAR_DMABUFCR 0x0048 #define RCAR_DMABUFCR_MBU(n) ((n) << 16) #define RCAR_DMABUFCR_ULB(n) ((n) << 0) #define RCAR_DMADPBASE 0x0050 #define RCAR_DMADPBASE_MASK 0xfffffff0 #define RCAR_DMADPBASE_SEL (1 << 0) #define RCAR_DMADPCR 0x0054 #define RCAR_DMADPCR_DIPT(n) ((n) << 24) #define RCAR_DMAFIXSAR 0x0010 #define RCAR_DMAFIXDAR 0x0014 #define RCAR_DMAFIXDPBASE 0x0060 /* Hardcode the MEMCPY transfer size to 4 bytes. */ #define RCAR_DMAC_MEMCPY_XFER_SIZE 4 /* ----------------------------------------------------------------------------- * Device access */ static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data) { if (reg == RCAR_DMAOR) writew(data, dmac->iomem + reg); else writel(data, dmac->iomem + reg); } static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg) { if (reg == RCAR_DMAOR) return readw(dmac->iomem + reg); else return readl(dmac->iomem + reg); } static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg) { if (reg == RCAR_DMARS) return readw(chan->iomem + reg); else return readl(chan->iomem + reg); } static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data) { if (reg == RCAR_DMARS) writew(data, chan->iomem + reg); else writel(data, chan->iomem + reg); } /* ----------------------------------------------------------------------------- * Initialization and configuration */ static bool rcar_dmac_chan_is_busy(struct rcar_dmac_chan *chan) { u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); return !!(chcr & (RCAR_DMACHCR_DE | RCAR_DMACHCR_TE)); } static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc = chan->desc.running; u32 chcr = desc->chcr; WARN_ON_ONCE(rcar_dmac_chan_is_busy(chan)); if (chan->mid_rid >= 0) rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid); if (desc->hwdescs.use) { struct rcar_dmac_xfer_chunk *chunk = list_first_entry(&desc->chunks, struct rcar_dmac_xfer_chunk, node); dev_dbg(chan->chan.device->dev, "chan%u: queue desc %p: %u@%pad\n", chan->index, desc, desc->nchunks, &desc->hwdescs.dma); #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, chunk->src_addr >> 32); rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, chunk->dst_addr >> 32); rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE, desc->hwdescs.dma >> 32); #endif rcar_dmac_chan_write(chan, RCAR_DMADPBASE, (desc->hwdescs.dma & 0xfffffff0) | RCAR_DMADPBASE_SEL); rcar_dmac_chan_write(chan, RCAR_DMACHCRB, RCAR_DMACHCRB_DCNT(desc->nchunks - 1) | RCAR_DMACHCRB_DRST); /* * Errata: When descriptor memory is accessed through an IOMMU * the DMADAR register isn't initialized automatically from the * first descriptor at beginning of transfer by the DMAC like it * should. Initialize it manually with the destination address * of the first chunk. */ rcar_dmac_chan_write(chan, RCAR_DMADAR, chunk->dst_addr & 0xffffffff); /* * Program the descriptor stage interrupt to occur after the end * of the first stage. */ rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(1)); chcr |= RCAR_DMACHCR_RPT_SAR | RCAR_DMACHCR_RPT_DAR | RCAR_DMACHCR_RPT_TCR | RCAR_DMACHCR_DPB; /* * If the descriptor isn't cyclic enable normal descriptor mode * and the transfer completion interrupt. */ if (!desc->cyclic) chcr |= RCAR_DMACHCR_DPM_ENABLED | RCAR_DMACHCR_IE; /* * If the descriptor is cyclic and has a callback enable the * descriptor stage interrupt in infinite repeat mode. */ else if (desc->async_tx.callback) chcr |= RCAR_DMACHCR_DPM_INFINITE | RCAR_DMACHCR_DSIE; /* * Otherwise just select infinite repeat mode without any * interrupt. */ else chcr |= RCAR_DMACHCR_DPM_INFINITE; } else { struct rcar_dmac_xfer_chunk *chunk = desc->running; dev_dbg(chan->chan.device->dev, "chan%u: queue chunk %p: %u@%pad -> %pad\n", chan->index, chunk, chunk->size, &chunk->src_addr, &chunk->dst_addr); #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, chunk->src_addr >> 32); rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, chunk->dst_addr >> 32); #endif rcar_dmac_chan_write(chan, RCAR_DMASAR, chunk->src_addr & 0xffffffff); rcar_dmac_chan_write(chan, RCAR_DMADAR, chunk->dst_addr & 0xffffffff); rcar_dmac_chan_write(chan, RCAR_DMATCR, chunk->size >> desc->xfer_shift); chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE; } rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAIE); } static int rcar_dmac_init(struct rcar_dmac *dmac) { u16 dmaor; /* Clear all channels and enable the DMAC globally. */ rcar_dmac_write(dmac, RCAR_DMACHCLR, dmac->channels_mask); rcar_dmac_write(dmac, RCAR_DMAOR, RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME); dmaor = rcar_dmac_read(dmac, RCAR_DMAOR); if ((dmaor & (RCAR_DMAOR_AE | RCAR_DMAOR_DME)) != RCAR_DMAOR_DME) { dev_warn(dmac->dev, "DMAOR initialization failed.\n"); return -EIO; } return 0; } /* ----------------------------------------------------------------------------- * Descriptors submission */ static dma_cookie_t rcar_dmac_tx_submit(struct dma_async_tx_descriptor *tx) { struct rcar_dmac_chan *chan = to_rcar_dmac_chan(tx->chan); struct rcar_dmac_desc *desc = to_rcar_dmac_desc(tx); unsigned long flags; dma_cookie_t cookie; spin_lock_irqsave(&chan->lock, flags); cookie = dma_cookie_assign(tx); dev_dbg(chan->chan.device->dev, "chan%u: submit #%d@%p\n", chan->index, tx->cookie, desc); list_add_tail(&desc->node, &chan->desc.pending); desc->running = list_first_entry(&desc->chunks, struct rcar_dmac_xfer_chunk, node); spin_unlock_irqrestore(&chan->lock, flags); return cookie; } /* ----------------------------------------------------------------------------- * Descriptors allocation and free */ /* * rcar_dmac_desc_alloc - Allocate a page worth of DMA descriptors * @chan: the DMA channel * @gfp: allocation flags */ static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) { struct rcar_dmac_desc_page *page; unsigned long flags; LIST_HEAD(list); unsigned int i; page = (void *)get_zeroed_page(gfp); if (!page) return -ENOMEM; for (i = 0; i < RCAR_DMAC_DESCS_PER_PAGE; ++i) { struct rcar_dmac_desc *desc = &page->descs[i]; dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan); desc->async_tx.tx_submit = rcar_dmac_tx_submit; INIT_LIST_HEAD(&desc->chunks); list_add_tail(&desc->node, &list); } spin_lock_irqsave(&chan->lock, flags); list_splice_tail(&list, &chan->desc.free); list_add_tail(&page->node, &chan->desc.pages); spin_unlock_irqrestore(&chan->lock, flags); return 0; } /* * rcar_dmac_desc_put - Release a DMA transfer descriptor * @chan: the DMA channel * @desc: the descriptor * * Put the descriptor and its transfer chunk descriptors back in the channel's * free descriptors lists. The descriptor's chunks list will be reinitialized to * an empty list as a result. * * The descriptor must have been removed from the channel's lists before calling * this function. */ static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc) { unsigned long flags; spin_lock_irqsave(&chan->lock, flags); list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free); list_add(&desc->node, &chan->desc.free); spin_unlock_irqrestore(&chan->lock, flags); } static void rcar_dmac_desc_recycle_acked(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc, *_desc; unsigned long flags; LIST_HEAD(list); /* * We have to temporarily move all descriptors from the wait list to a * local list as iterating over the wait list, even with * list_for_each_entry_safe, isn't safe if we release the channel lock * around the rcar_dmac_desc_put() call. */ spin_lock_irqsave(&chan->lock, flags); list_splice_init(&chan->desc.wait, &list); spin_unlock_irqrestore(&chan->lock, flags); list_for_each_entry_safe(desc, _desc, &list, node) { if (async_tx_test_ack(&desc->async_tx)) { list_del(&desc->node); rcar_dmac_desc_put(chan, desc); } } if (list_empty(&list)) return; /* Put the remaining descriptors back in the wait list. */ spin_lock_irqsave(&chan->lock, flags); list_splice(&list, &chan->desc.wait); spin_unlock_irqrestore(&chan->lock, flags); } /* * rcar_dmac_desc_get - Allocate a descriptor for a DMA transfer * @chan: the DMA channel * * Locking: This function must be called in a non-atomic context. * * Return: A pointer to the allocated descriptor or NULL if no descriptor can * be allocated. */ static struct rcar_dmac_desc *rcar_dmac_desc_get(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc; unsigned long flags; int ret; /* Recycle acked descriptors before attempting allocation. */ rcar_dmac_desc_recycle_acked(chan); spin_lock_irqsave(&chan->lock, flags); while (list_empty(&chan->desc.free)) { /* * No free descriptors, allocate a page worth of them and try * again, as someone else could race us to get the newly * allocated descriptors. If the allocation fails return an * error. */ spin_unlock_irqrestore(&chan->lock, flags); ret = rcar_dmac_desc_alloc(chan, GFP_NOWAIT); if (ret < 0) return NULL; spin_lock_irqsave(&chan->lock, flags); } desc = list_first_entry(&chan->desc.free, struct rcar_dmac_desc, node); list_del(&desc->node); spin_unlock_irqrestore(&chan->lock, flags); return desc; } /* * rcar_dmac_xfer_chunk_alloc - Allocate a page worth of transfer chunks * @chan: the DMA channel * @gfp: allocation flags */ static int rcar_dmac_xfer_chunk_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) { struct rcar_dmac_desc_page *page; unsigned long flags; LIST_HEAD(list); unsigned int i; page = (void *)get_zeroed_page(gfp); if (!page) return -ENOMEM; for (i = 0; i < RCAR_DMAC_XFER_CHUNKS_PER_PAGE; ++i) { struct rcar_dmac_xfer_chunk *chunk = &page->chunks[i]; list_add_tail(&chunk->node, &list); } spin_lock_irqsave(&chan->lock, flags); list_splice_tail(&list, &chan->desc.chunks_free); list_add_tail(&page->node, &chan->desc.pages); spin_unlock_irqrestore(&chan->lock, flags); return 0; } /* * rcar_dmac_xfer_chunk_get - Allocate a transfer chunk for a DMA transfer * @chan: the DMA channel * * Locking: This function must be called in a non-atomic context. * * Return: A pointer to the allocated transfer chunk descriptor or NULL if no * descriptor can be allocated. */ static struct rcar_dmac_xfer_chunk * rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan) { struct rcar_dmac_xfer_chunk *chunk; unsigned long flags; int ret; spin_lock_irqsave(&chan->lock, flags); while (list_empty(&chan->desc.chunks_free)) { /* * No free descriptors, allocate a page worth of them and try * again, as someone else could race us to get the newly * allocated descriptors. If the allocation fails return an * error. */ spin_unlock_irqrestore(&chan->lock, flags); ret = rcar_dmac_xfer_chunk_alloc(chan, GFP_NOWAIT); if (ret < 0) return NULL; spin_lock_irqsave(&chan->lock, flags); } chunk = list_first_entry(&chan->desc.chunks_free, struct rcar_dmac_xfer_chunk, node); list_del(&chunk->node); spin_unlock_irqrestore(&chan->lock, flags); return chunk; } static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc, size_t size) { /* * dma_alloc_coherent() allocates memory in page size increments. To * avoid reallocating the hardware descriptors when the allocated size * wouldn't change align the requested size to a multiple of the page * size. */ size = PAGE_ALIGN(size); if (desc->hwdescs.size == size) return; if (desc->hwdescs.mem) { dma_free_coherent(chan->chan.device->dev, desc->hwdescs.size, desc->hwdescs.mem, desc->hwdescs.dma); desc->hwdescs.mem = NULL; desc->hwdescs.size = 0; } if (!size) return; desc->hwdescs.mem = dma_alloc_coherent(chan->chan.device->dev, size, &desc->hwdescs.dma, GFP_NOWAIT); if (!desc->hwdescs.mem) return; desc->hwdescs.size = size; } static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc) { struct rcar_dmac_xfer_chunk *chunk; struct rcar_dmac_hw_desc *hwdesc; rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc)); hwdesc = desc->hwdescs.mem; if (!hwdesc) return -ENOMEM; list_for_each_entry(chunk, &desc->chunks, node) { hwdesc->sar = chunk->src_addr; hwdesc->dar = chunk->dst_addr; hwdesc->tcr = chunk->size >> desc->xfer_shift; hwdesc++; } return 0; } /* ----------------------------------------------------------------------------- * Stop and reset */ static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan) { u32 chcr; unsigned int i; /* * Ensure that the setting of the DE bit is actually 0 after * clearing it. */ for (i = 0; i < 1024; i++) { chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); if (!(chcr & RCAR_DMACHCR_DE)) return; udelay(1); } dev_err(chan->chan.device->dev, "CHCR DE check error\n"); } static void rcar_dmac_clear_chcr_de(struct rcar_dmac_chan *chan) { u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); /* set DE=0 and flush remaining data */ rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE)); /* make sure all remaining data was flushed */ rcar_dmac_chcr_de_barrier(chan); } static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) { u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE | RCAR_DMACHCR_TE | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAE | RCAR_DMACHCR_CAIE); rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); rcar_dmac_chcr_de_barrier(chan); } static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc, *_desc; unsigned long flags; LIST_HEAD(descs); spin_lock_irqsave(&chan->lock, flags); /* Move all non-free descriptors to the local lists. */ list_splice_init(&chan->desc.pending, &descs); list_splice_init(&chan->desc.active, &descs); list_splice_init(&chan->desc.done, &descs); list_splice_init(&chan->desc.wait, &descs); chan->desc.running = NULL; spin_unlock_irqrestore(&chan->lock, flags); list_for_each_entry_safe(desc, _desc, &descs, node) { list_del(&desc->node); rcar_dmac_desc_put(chan, desc); } } static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac) { unsigned int i; /* Stop all channels. */ for (i = 0; i < dmac->n_channels; ++i) { struct rcar_dmac_chan *chan = &dmac->channels[i]; if (!(dmac->channels_mask & BIT(i))) continue; /* Stop and reinitialize the channel. */ spin_lock_irq(&chan->lock); rcar_dmac_chan_halt(chan); spin_unlock_irq(&chan->lock); } } static int rcar_dmac_chan_pause(struct dma_chan *chan) { unsigned long flags; struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); spin_lock_irqsave(&rchan->lock, flags); rcar_dmac_clear_chcr_de(rchan); spin_unlock_irqrestore(&rchan->lock, flags); return 0; } /* ----------------------------------------------------------------------------- * Descriptors preparation */ static void rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc) { static const u32 chcr_ts[] = { RCAR_DMACHCR_TS_1B, RCAR_DMACHCR_TS_2B, RCAR_DMACHCR_TS_4B, RCAR_DMACHCR_TS_8B, RCAR_DMACHCR_TS_16B, RCAR_DMACHCR_TS_32B, RCAR_DMACHCR_TS_64B, }; unsigned int xfer_size; u32 chcr; switch (desc->direction) { case DMA_DEV_TO_MEM: chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED | RCAR_DMACHCR_RS_DMARS; xfer_size = chan->src.xfer_size; break; case DMA_MEM_TO_DEV: chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC | RCAR_DMACHCR_RS_DMARS; xfer_size = chan->dst.xfer_size; break; case DMA_MEM_TO_MEM: default: chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_INC | RCAR_DMACHCR_RS_AUTO; xfer_size = RCAR_DMAC_MEMCPY_XFER_SIZE; break; } desc->xfer_shift = ilog2(xfer_size); desc->chcr = chcr | chcr_ts[desc->xfer_shift]; } /* * rcar_dmac_chan_prep_sg - prepare transfer descriptors from an SG list * * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also * converted to scatter-gather to guarantee consistent locking and a correct * list manipulation. For slave DMA direction carries the usual meaning, and, * logically, the SG list is RAM and the addr variable contains slave address, * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM * and the SG list contains only one element and points at the source buffer. */ static struct dma_async_tx_descriptor * rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl, unsigned int sg_len, dma_addr_t dev_addr, enum dma_transfer_direction dir, unsigned long dma_flags, bool cyclic) { struct rcar_dmac_xfer_chunk *chunk; struct rcar_dmac_desc *desc; struct scatterlist *sg; unsigned int nchunks = 0; unsigned int max_chunk_size; unsigned int full_size = 0; bool cross_boundary = false; unsigned int i; #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT u32 high_dev_addr; u32 high_mem_addr; #endif desc = rcar_dmac_desc_get(chan); if (!desc) return NULL; desc->async_tx.flags = dma_flags; desc->async_tx.cookie = -EBUSY; desc->cyclic = cyclic; desc->direction = dir; rcar_dmac_chan_configure_desc(chan, desc); max_chunk_size = RCAR_DMATCR_MASK << desc->xfer_shift; /* * Allocate and fill the transfer chunk descriptors. We own the only * reference to the DMA descriptor, there's no need for locking. */ for_each_sg(sgl, sg, sg_len, i) { dma_addr_t mem_addr = sg_dma_address(sg); unsigned int len = sg_dma_len(sg); full_size += len; #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT if (i == 0) { high_dev_addr = dev_addr >> 32; high_mem_addr = mem_addr >> 32; } if ((dev_addr >> 32 != high_dev_addr) || (mem_addr >> 32 != high_mem_addr)) cross_boundary = true; #endif while (len) { unsigned int size = min(len, max_chunk_size); #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT /* * Prevent individual transfers from crossing 4GB * boundaries. */ if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) { size = ALIGN(dev_addr, 1ULL << 32) - dev_addr; cross_boundary = true; } if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) { size = ALIGN(mem_addr, 1ULL << 32) - mem_addr; cross_boundary = true; } #endif chunk = rcar_dmac_xfer_chunk_get(chan); if (!chunk) { rcar_dmac_desc_put(chan, desc); return NULL; } if (dir == DMA_DEV_TO_MEM) { chunk->src_addr = dev_addr; chunk->dst_addr = mem_addr; } else { chunk->src_addr = mem_addr; chunk->dst_addr = dev_addr; } chunk->size = size; dev_dbg(chan->chan.device->dev, "chan%u: chunk %p/%p sgl %u@%p, %u/%u %pad -> %pad\n", chan->index, chunk, desc, i, sg, size, len, &chunk->src_addr, &chunk->dst_addr); mem_addr += size; if (dir == DMA_MEM_TO_MEM) dev_addr += size; len -= size; list_add_tail(&chunk->node, &desc->chunks); nchunks++; } } desc->nchunks = nchunks; desc->size = full_size; /* * Use hardware descriptor lists if possible when more than one chunk * needs to be transferred (otherwise they don't make much sense). * * Source/Destination address should be located in same 4GiB region * in the 40bit address space when it uses Hardware descriptor, * and cross_boundary is checking it. */ desc->hwdescs.use = !cross_boundary && nchunks > 1; if (desc->hwdescs.use) { if (rcar_dmac_fill_hwdesc(chan, desc) < 0) desc->hwdescs.use = false; } return &desc->async_tx; } /* ----------------------------------------------------------------------------- * DMA engine operations */ static int rcar_dmac_alloc_chan_resources(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); int ret; INIT_LIST_HEAD(&rchan->desc.chunks_free); INIT_LIST_HEAD(&rchan->desc.pages); /* Preallocate descriptors. */ ret = rcar_dmac_xfer_chunk_alloc(rchan, GFP_KERNEL); if (ret < 0) return -ENOMEM; ret = rcar_dmac_desc_alloc(rchan, GFP_KERNEL); if (ret < 0) return -ENOMEM; return pm_runtime_get_sync(chan->device->dev); } static void rcar_dmac_free_chan_resources(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct rcar_dmac *dmac = to_rcar_dmac(chan->device); struct rcar_dmac_chan_map *map = &rchan->map; struct rcar_dmac_desc_page *page, *_page; struct rcar_dmac_desc *desc; LIST_HEAD(list); /* Protect against ISR */ spin_lock_irq(&rchan->lock); rcar_dmac_chan_halt(rchan); spin_unlock_irq(&rchan->lock); /* * Now no new interrupts will occur, but one might already be * running. Wait for it to finish before freeing resources. */ synchronize_irq(rchan->irq); if (rchan->mid_rid >= 0) { /* The caller is holding dma_list_mutex */ clear_bit(rchan->mid_rid, dmac->modules); rchan->mid_rid = -EINVAL; } list_splice_init(&rchan->desc.free, &list); list_splice_init(&rchan->desc.pending, &list); list_splice_init(&rchan->desc.active, &list); list_splice_init(&rchan->desc.done, &list); list_splice_init(&rchan->desc.wait, &list); rchan->desc.running = NULL; list_for_each_entry(desc, &list, node) rcar_dmac_realloc_hwdesc(rchan, desc, 0); list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) { list_del(&page->node); free_page((unsigned long)page); } /* Remove slave mapping if present. */ if (map->slave.xfer_size) { dma_unmap_resource(chan->device->dev, map->addr, map->slave.xfer_size, map->dir, 0); map->slave.xfer_size = 0; } pm_runtime_put(chan->device->dev); } static struct dma_async_tx_descriptor * rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src, size_t len, unsigned long flags) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct scatterlist sgl; if (!len) return NULL; sg_init_table(&sgl, 1); sg_set_page(&sgl, pfn_to_page(PFN_DOWN(dma_src)), len, offset_in_page(dma_src)); sg_dma_address(&sgl) = dma_src; sg_dma_len(&sgl) = len; return rcar_dmac_chan_prep_sg(rchan, &sgl, 1, dma_dest, DMA_MEM_TO_MEM, flags, false); } static int rcar_dmac_map_slave_addr(struct dma_chan *chan, enum dma_transfer_direction dir) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct rcar_dmac_chan_map *map = &rchan->map; phys_addr_t dev_addr; size_t dev_size; enum dma_data_direction dev_dir; if (dir == DMA_DEV_TO_MEM) { dev_addr = rchan->src.slave_addr; dev_size = rchan->src.xfer_size; dev_dir = DMA_TO_DEVICE; } else { dev_addr = rchan->dst.slave_addr; dev_size = rchan->dst.xfer_size; dev_dir = DMA_FROM_DEVICE; } /* Reuse current map if possible. */ if (dev_addr == map->slave.slave_addr && dev_size == map->slave.xfer_size && dev_dir == map->dir) return 0; /* Remove old mapping if present. */ if (map->slave.xfer_size) dma_unmap_resource(chan->device->dev, map->addr, map->slave.xfer_size, map->dir, 0); map->slave.xfer_size = 0; /* Create new slave address map. */ map->addr = dma_map_resource(chan->device->dev, dev_addr, dev_size, dev_dir, 0); if (dma_mapping_error(chan->device->dev, map->addr)) { dev_err(chan->device->dev, "chan%u: failed to map %zx@%pap", rchan->index, dev_size, &dev_addr); return -EIO; } dev_dbg(chan->device->dev, "chan%u: map %zx@%pap to %pad dir: %s\n", rchan->index, dev_size, &dev_addr, &map->addr, dev_dir == DMA_TO_DEVICE ? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE"); map->slave.slave_addr = dev_addr; map->slave.xfer_size = dev_size; map->dir = dev_dir; return 0; } static struct dma_async_tx_descriptor * rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags, void *context) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); /* Someone calling slave DMA on a generic channel? */ if (rchan->mid_rid < 0 || !sg_len || !sg_dma_len(sgl)) { dev_warn(chan->device->dev, "%s: bad parameter: len=%d, id=%d\n", __func__, sg_len, rchan->mid_rid); return NULL; } if (rcar_dmac_map_slave_addr(chan, dir)) return NULL; return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, dir, flags, false); } #define RCAR_DMAC_MAX_SG_LEN 32 static struct dma_async_tx_descriptor * rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, size_t period_len, enum dma_transfer_direction dir, unsigned long flags) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct dma_async_tx_descriptor *desc; struct scatterlist *sgl; unsigned int sg_len; unsigned int i; /* Someone calling slave DMA on a generic channel? */ if (rchan->mid_rid < 0 || buf_len < period_len) { dev_warn(chan->device->dev, "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", __func__, buf_len, period_len, rchan->mid_rid); return NULL; } if (rcar_dmac_map_slave_addr(chan, dir)) return NULL; sg_len = buf_len / period_len; if (sg_len > RCAR_DMAC_MAX_SG_LEN) { dev_err(chan->device->dev, "chan%u: sg length %d exceeds limit %d", rchan->index, sg_len, RCAR_DMAC_MAX_SG_LEN); return NULL; } /* * Allocate the sg list dynamically as it would consume too much stack * space. */ sgl = kcalloc(sg_len, sizeof(*sgl), GFP_NOWAIT); if (!sgl) return NULL; sg_init_table(sgl, sg_len); for (i = 0; i < sg_len; ++i) { dma_addr_t src = buf_addr + (period_len * i); sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, offset_in_page(src)); sg_dma_address(&sgl[i]) = src; sg_dma_len(&sgl[i]) = period_len; } desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, rchan->map.addr, dir, flags, true); kfree(sgl); return desc; } static int rcar_dmac_device_config(struct dma_chan *chan, struct dma_slave_config *cfg) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); /* * We could lock this, but you shouldn't be configuring the * channel, while using it... */ rchan->src.slave_addr = cfg->src_addr; rchan->dst.slave_addr = cfg->dst_addr; rchan->src.xfer_size = cfg->src_addr_width; rchan->dst.xfer_size = cfg->dst_addr_width; return 0; } static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); unsigned long flags; spin_lock_irqsave(&rchan->lock, flags); rcar_dmac_chan_halt(rchan); spin_unlock_irqrestore(&rchan->lock, flags); /* * FIXME: No new interrupt can occur now, but the IRQ thread might still * be running. */ rcar_dmac_chan_reinit(rchan); return 0; } static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, dma_cookie_t cookie) { struct rcar_dmac_desc *desc = chan->desc.running; struct rcar_dmac_xfer_chunk *running = NULL; struct rcar_dmac_xfer_chunk *chunk; enum dma_status status; unsigned int residue = 0; unsigned int dptr = 0; unsigned int chcrb; unsigned int tcrb; unsigned int i; if (!desc) return 0; /* * If the cookie corresponds to a descriptor that has been completed * there is no residue. The same check has already been performed by the * caller but without holding the channel lock, so the descriptor could * now be complete. */ status = dma_cookie_status(&chan->chan, cookie, NULL); if (status == DMA_COMPLETE) return 0; /* * If the cookie doesn't correspond to the currently running transfer * then the descriptor hasn't been processed yet, and the residue is * equal to the full descriptor size. * Also, a client driver is possible to call this function before * rcar_dmac_isr_channel_thread() runs. In this case, the "desc.running" * will be the next descriptor, and the done list will appear. So, if * the argument cookie matches the done list's cookie, we can assume * the residue is zero. */ if (cookie != desc->async_tx.cookie) { list_for_each_entry(desc, &chan->desc.done, node) { if (cookie == desc->async_tx.cookie) return 0; } list_for_each_entry(desc, &chan->desc.pending, node) { if (cookie == desc->async_tx.cookie) return desc->size; } list_for_each_entry(desc, &chan->desc.active, node) { if (cookie == desc->async_tx.cookie) return desc->size; } /* * No descriptor found for the cookie, there's thus no residue. * This shouldn't happen if the calling driver passes a correct * cookie value. */ WARN(1, "No descriptor for cookie!"); return 0; } /* * We need to read two registers. * Make sure the control register does not skip to next chunk * while reading the counter. * Trying it 3 times should be enough: Initial read, retry, retry * for the paranoid. */ for (i = 0; i < 3; i++) { chcrb = rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & RCAR_DMACHCRB_DPTR_MASK; tcrb = rcar_dmac_chan_read(chan, RCAR_DMATCRB); /* Still the same? */ if (chcrb == (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & RCAR_DMACHCRB_DPTR_MASK)) break; } WARN_ONCE(i >= 3, "residue might be not continuous!"); /* * In descriptor mode the descriptor running pointer is not maintained * by the interrupt handler, find the running descriptor from the * descriptor pointer field in the CHCRB register. In non-descriptor * mode just use the running descriptor pointer. */ if (desc->hwdescs.use) { dptr = chcrb >> RCAR_DMACHCRB_DPTR_SHIFT; if (dptr == 0) dptr = desc->nchunks; dptr--; WARN_ON(dptr >= desc->nchunks); } else { running = desc->running; } /* Compute the size of all chunks still to be transferred. */ list_for_each_entry_reverse(chunk, &desc->chunks, node) { if (chunk == running || ++dptr == desc->nchunks) break; residue += chunk->size; } /* Add the residue for the current chunk. */ residue += tcrb << desc->xfer_shift; return residue; } static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); enum dma_status status; unsigned long flags; unsigned int residue; bool cyclic; status = dma_cookie_status(chan, cookie, txstate); if (status == DMA_COMPLETE || !txstate) return status; spin_lock_irqsave(&rchan->lock, flags); residue = rcar_dmac_chan_get_residue(rchan, cookie); cyclic = rchan->desc.running ? rchan->desc.running->cyclic : false; spin_unlock_irqrestore(&rchan->lock, flags); /* if there's no residue, the cookie is complete */ if (!residue && !cyclic) return DMA_COMPLETE; dma_set_residue(txstate, residue); return status; } static void rcar_dmac_issue_pending(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); unsigned long flags; spin_lock_irqsave(&rchan->lock, flags); if (list_empty(&rchan->desc.pending)) goto done; /* Append the pending list to the active list. */ list_splice_tail_init(&rchan->desc.pending, &rchan->desc.active); /* * If no transfer is running pick the first descriptor from the active * list and start the transfer. */ if (!rchan->desc.running) { struct rcar_dmac_desc *desc; desc = list_first_entry(&rchan->desc.active, struct rcar_dmac_desc, node); rchan->desc.running = desc; rcar_dmac_chan_start_xfer(rchan); } done: spin_unlock_irqrestore(&rchan->lock, flags); } static void rcar_dmac_device_synchronize(struct dma_chan *chan) { struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); synchronize_irq(rchan->irq); } /* ----------------------------------------------------------------------------- * IRQ handling */ static irqreturn_t rcar_dmac_isr_desc_stage_end(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc = chan->desc.running; unsigned int stage; if (WARN_ON(!desc || !desc->cyclic)) { /* * This should never happen, there should always be a running * cyclic descriptor when a descriptor stage end interrupt is * triggered. Warn and return. */ return IRQ_NONE; } /* Program the interrupt pointer to the next stage. */ stage = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(stage)); return IRQ_WAKE_THREAD; } static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan) { struct rcar_dmac_desc *desc = chan->desc.running; irqreturn_t ret = IRQ_WAKE_THREAD; if (WARN_ON_ONCE(!desc)) { /* * This should never happen, there should always be a running * descriptor when a transfer end interrupt is triggered. Warn * and return. */ return IRQ_NONE; } /* * The transfer end interrupt isn't generated for each chunk when using * descriptor mode. Only update the running chunk pointer in * non-descriptor mode. */ if (!desc->hwdescs.use) { /* * If we haven't completed the last transfer chunk simply move * to the next one. Only wake the IRQ thread if the transfer is * cyclic. */ if (!list_is_last(&desc->running->node, &desc->chunks)) { desc->running = list_next_entry(desc->running, node); if (!desc->cyclic) ret = IRQ_HANDLED; goto done; } /* * We've completed the last transfer chunk. If the transfer is * cyclic, move back to the first one. */ if (desc->cyclic) { desc->running = list_first_entry(&desc->chunks, struct rcar_dmac_xfer_chunk, node); goto done; } } /* The descriptor is complete, move it to the done list. */ list_move_tail(&desc->node, &chan->desc.done); /* Queue the next descriptor, if any. */ if (!list_empty(&chan->desc.active)) chan->desc.running = list_first_entry(&chan->desc.active, struct rcar_dmac_desc, node); else chan->desc.running = NULL; done: if (chan->desc.running) rcar_dmac_chan_start_xfer(chan); return ret; } static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev) { u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE; struct rcar_dmac_chan *chan = dev; irqreturn_t ret = IRQ_NONE; bool reinit = false; u32 chcr; spin_lock(&chan->lock); chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); if (chcr & RCAR_DMACHCR_CAE) { struct rcar_dmac *dmac = to_rcar_dmac(chan->chan.device); /* * We don't need to call rcar_dmac_chan_halt() * because channel is already stopped in error case. * We need to clear register and check DE bit as recovery. */ rcar_dmac_write(dmac, RCAR_DMACHCLR, 1 << chan->index); rcar_dmac_chcr_de_barrier(chan); reinit = true; goto spin_lock_end; } if (chcr & RCAR_DMACHCR_TE) mask |= RCAR_DMACHCR_DE; rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask); if (mask & RCAR_DMACHCR_DE) rcar_dmac_chcr_de_barrier(chan); if (chcr & RCAR_DMACHCR_DSE) ret |= rcar_dmac_isr_desc_stage_end(chan); if (chcr & RCAR_DMACHCR_TE) ret |= rcar_dmac_isr_transfer_end(chan); spin_lock_end: spin_unlock(&chan->lock); if (reinit) { dev_err(chan->chan.device->dev, "Channel Address Error\n"); rcar_dmac_chan_reinit(chan); ret = IRQ_HANDLED; } return ret; } static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev) { struct rcar_dmac_chan *chan = dev; struct rcar_dmac_desc *desc; struct dmaengine_desc_callback cb; spin_lock_irq(&chan->lock); /* For cyclic transfers notify the user after every chunk. */ if (chan->desc.running && chan->desc.running->cyclic) { desc = chan->desc.running; dmaengine_desc_get_callback(&desc->async_tx, &cb); if (dmaengine_desc_callback_valid(&cb)) { spin_unlock_irq(&chan->lock); dmaengine_desc_callback_invoke(&cb, NULL); spin_lock_irq(&chan->lock); } } /* * Call the callback function for all descriptors on the done list and * move them to the ack wait list. */ while (!list_empty(&chan->desc.done)) { desc = list_first_entry(&chan->desc.done, struct rcar_dmac_desc, node); dma_cookie_complete(&desc->async_tx); list_del(&desc->node); dmaengine_desc_get_callback(&desc->async_tx, &cb); if (dmaengine_desc_callback_valid(&cb)) { spin_unlock_irq(&chan->lock); /* * We own the only reference to this descriptor, we can * safely dereference it without holding the channel * lock. */ dmaengine_desc_callback_invoke(&cb, NULL); spin_lock_irq(&chan->lock); } list_add_tail(&desc->node, &chan->desc.wait); } spin_unlock_irq(&chan->lock); /* Recycle all acked descriptors. */ rcar_dmac_desc_recycle_acked(chan); return IRQ_HANDLED; } /* ----------------------------------------------------------------------------- * OF xlate and channel filter */ static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg) { struct rcar_dmac *dmac = to_rcar_dmac(chan->device); struct of_phandle_args *dma_spec = arg; /* * FIXME: Using a filter on OF platforms is a nonsense. The OF xlate * function knows from which device it wants to allocate a channel from, * and would be perfectly capable of selecting the channel it wants. * Forcing it to call dma_request_channel() and iterate through all * channels from all controllers is just pointless. */ if (chan->device->device_config != rcar_dmac_device_config) return false; return !test_and_set_bit(dma_spec->args[0], dmac->modules); } static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct rcar_dmac_chan *rchan; struct dma_chan *chan; dma_cap_mask_t mask; if (dma_spec->args_count != 1) return NULL; /* Only slave DMA channels can be allocated via DT */ dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); chan = __dma_request_channel(&mask, rcar_dmac_chan_filter, dma_spec, ofdma->of_node); if (!chan) return NULL; rchan = to_rcar_dmac_chan(chan); rchan->mid_rid = dma_spec->args[0]; return chan; } /* ----------------------------------------------------------------------------- * Power management */ #ifdef CONFIG_PM static int rcar_dmac_runtime_suspend(struct device *dev) { return 0; } static int rcar_dmac_runtime_resume(struct device *dev) { struct rcar_dmac *dmac = dev_get_drvdata(dev); return rcar_dmac_init(dmac); } #endif static const struct dev_pm_ops rcar_dmac_pm = { /* * TODO for system sleep/resume: * - Wait for the current transfer to complete and stop the device, * - Resume transfers, if any. */ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume, NULL) }; /* ----------------------------------------------------------------------------- * Probe and remove */ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, struct rcar_dmac_chan *rchan, const struct rcar_dmac_of_data *data, unsigned int index) { struct platform_device *pdev = to_platform_device(dmac->dev); struct dma_chan *chan = &rchan->chan; char pdev_irqname[5]; char *irqname; int ret; rchan->index = index; rchan->iomem = dmac->iomem + data->chan_offset_base + data->chan_offset_stride * index; rchan->mid_rid = -EINVAL; spin_lock_init(&rchan->lock); INIT_LIST_HEAD(&rchan->desc.free); INIT_LIST_HEAD(&rchan->desc.pending); INIT_LIST_HEAD(&rchan->desc.active); INIT_LIST_HEAD(&rchan->desc.done); INIT_LIST_HEAD(&rchan->desc.wait); /* Request the channel interrupt. */ sprintf(pdev_irqname, "ch%u", index); rchan->irq = platform_get_irq_byname(pdev, pdev_irqname); if (rchan->irq < 0) return -ENODEV; irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", dev_name(dmac->dev), index); if (!irqname) return -ENOMEM; /* * Initialize the DMA engine channel and add it to the DMA engine * channels list. */ chan->device = &dmac->engine; dma_cookie_init(chan); list_add_tail(&chan->device_node, &dmac->engine.channels); ret = devm_request_threaded_irq(dmac->dev, rchan->irq, rcar_dmac_isr_channel, rcar_dmac_isr_channel_thread, 0, irqname, rchan); if (ret) { dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", rchan->irq, ret); return ret; } return 0; } #define RCAR_DMAC_MAX_CHANNELS 32 static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac) { struct device_node *np = dev->of_node; int ret; ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); if (ret < 0) { dev_err(dev, "unable to read dma-channels property\n"); return ret; } /* The hardware and driver don't support more than 32 bits in CHCLR */ if (dmac->n_channels <= 0 || dmac->n_channels >= RCAR_DMAC_MAX_CHANNELS) { dev_err(dev, "invalid number of channels %u\n", dmac->n_channels); return -EINVAL; } /* * If the driver is unable to read dma-channel-mask property, * the driver assumes that it can use all channels. */ dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0); of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask); /* If the property has out-of-channel mask, this driver clears it */ dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0); return 0; } static int rcar_dmac_probe(struct platform_device *pdev) { const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES | DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES; struct dma_device *engine; struct rcar_dmac *dmac; const struct rcar_dmac_of_data *data; unsigned int i; int ret; data = of_device_get_match_data(&pdev->dev); if (!data) return -EINVAL; dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); if (!dmac) return -ENOMEM; dmac->dev = &pdev->dev; platform_set_drvdata(pdev, dmac); dmac->dev->dma_parms = &dmac->parms; dma_set_max_seg_size(dmac->dev, RCAR_DMATCR_MASK); dma_set_mask_and_coherent(dmac->dev, DMA_BIT_MASK(40)); ret = rcar_dmac_parse_of(&pdev->dev, dmac); if (ret < 0) return ret; /* * A still unconfirmed hardware bug prevents the IPMMU microTLB 0 to be * flushed correctly, resulting in memory corruption. DMAC 0 channel 0 * is connected to microTLB 0 on currently supported platforms, so we * can't use it with the IPMMU. As the IOMMU API operates at the device * level we can't disable it selectively, so ignore channel 0 for now if * the device is part of an IOMMU group. */ if (device_iommu_mapped(&pdev->dev)) dmac->channels_mask &= ~BIT(0); dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, sizeof(*dmac->channels), GFP_KERNEL); if (!dmac->channels) return -ENOMEM; /* Request resources. */ dmac->iomem = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(dmac->iomem)) return PTR_ERR(dmac->iomem); /* Enable runtime PM and initialize the device. */ pm_runtime_enable(&pdev->dev); ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); return ret; } ret = rcar_dmac_init(dmac); pm_runtime_put(&pdev->dev); if (ret) { dev_err(&pdev->dev, "failed to reset device\n"); goto error; } /* Initialize engine */ engine = &dmac->engine; dma_cap_set(DMA_MEMCPY, engine->cap_mask); dma_cap_set(DMA_SLAVE, engine->cap_mask); engine->dev = &pdev->dev; engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE); engine->src_addr_widths = widths; engine->dst_addr_widths = widths; engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources; engine->device_free_chan_resources = rcar_dmac_free_chan_resources; engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy; engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg; engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic; engine->device_config = rcar_dmac_device_config; engine->device_pause = rcar_dmac_chan_pause; engine->device_terminate_all = rcar_dmac_chan_terminate_all; engine->device_tx_status = rcar_dmac_tx_status; engine->device_issue_pending = rcar_dmac_issue_pending; engine->device_synchronize = rcar_dmac_device_synchronize; INIT_LIST_HEAD(&engine->channels); for (i = 0; i < dmac->n_channels; ++i) { if (!(dmac->channels_mask & BIT(i))) continue; ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], data, i); if (ret < 0) goto error; } /* Register the DMAC as a DMA provider for DT. */ ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate, NULL); if (ret < 0) goto error; /* * Register the DMA engine device. * * Default transfer size of 32 bytes requires 32-byte alignment. */ ret = dma_async_device_register(engine); if (ret < 0) goto error; return 0; error: of_dma_controller_free(pdev->dev.of_node); pm_runtime_disable(&pdev->dev); return ret; } static int rcar_dmac_remove(struct platform_device *pdev) { struct rcar_dmac *dmac = platform_get_drvdata(pdev); of_dma_controller_free(pdev->dev.of_node); dma_async_device_unregister(&dmac->engine); pm_runtime_disable(&pdev->dev); return 0; } static void rcar_dmac_shutdown(struct platform_device *pdev) { struct rcar_dmac *dmac = platform_get_drvdata(pdev); rcar_dmac_stop_all_chan(dmac); } static const struct rcar_dmac_of_data rcar_dmac_data = { .chan_offset_base = 0x8000, .chan_offset_stride = 0x80, }; static const struct of_device_id rcar_dmac_of_ids[] = { { .compatible = "renesas,rcar-dmac", .data = &rcar_dmac_data, }, { /* Sentinel */ } }; MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids); static struct platform_driver rcar_dmac_driver = { .driver = { .pm = &rcar_dmac_pm, .name = "rcar-dmac", .of_match_table = rcar_dmac_of_ids, }, .probe = rcar_dmac_probe, .remove = rcar_dmac_remove, .shutdown = rcar_dmac_shutdown, }; module_platform_driver(rcar_dmac_driver); MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver"); MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); MODULE_LICENSE("GPL v2");
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