/* * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd. * Author: Guennadi Liakhovetski * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "dmaengine.h" #define NBPF_REG_CHAN_OFFSET 0 #define NBPF_REG_CHAN_SIZE 0x40 /* Channel Current Transaction Byte register */ #define NBPF_CHAN_CUR_TR_BYTE 0x20 /* Channel Status register */ #define NBPF_CHAN_STAT 0x24 #define NBPF_CHAN_STAT_EN 1 #define NBPF_CHAN_STAT_TACT 4 #define NBPF_CHAN_STAT_ERR 0x10 #define NBPF_CHAN_STAT_END 0x20 #define NBPF_CHAN_STAT_TC 0x40 #define NBPF_CHAN_STAT_DER 0x400 /* Channel Control register */ #define NBPF_CHAN_CTRL 0x28 #define NBPF_CHAN_CTRL_SETEN 1 #define NBPF_CHAN_CTRL_CLREN 2 #define NBPF_CHAN_CTRL_STG 4 #define NBPF_CHAN_CTRL_SWRST 8 #define NBPF_CHAN_CTRL_CLRRQ 0x10 #define NBPF_CHAN_CTRL_CLREND 0x20 #define NBPF_CHAN_CTRL_CLRTC 0x40 #define NBPF_CHAN_CTRL_SETSUS 0x100 #define NBPF_CHAN_CTRL_CLRSUS 0x200 /* Channel Configuration register */ #define NBPF_CHAN_CFG 0x2c #define NBPF_CHAN_CFG_SEL 7 /* terminal SELect: 0..7 */ #define NBPF_CHAN_CFG_REQD 8 /* REQuest Direction: DMAREQ is 0: input, 1: output */ #define NBPF_CHAN_CFG_LOEN 0x10 /* LOw ENable: low DMA request line is: 0: inactive, 1: active */ #define NBPF_CHAN_CFG_HIEN 0x20 /* HIgh ENable: high DMA request line is: 0: inactive, 1: active */ #define NBPF_CHAN_CFG_LVL 0x40 /* LeVeL: DMA request line is sensed as 0: edge, 1: level */ #define NBPF_CHAN_CFG_AM 0x700 /* ACK Mode: 0: Pulse mode, 1: Level mode, b'1x: Bus Cycle */ #define NBPF_CHAN_CFG_SDS 0xf000 /* Source Data Size: 0: 8 bits,... , 7: 1024 bits */ #define NBPF_CHAN_CFG_DDS 0xf0000 /* Destination Data Size: as above */ #define NBPF_CHAN_CFG_SAD 0x100000 /* Source ADdress counting: 0: increment, 1: fixed */ #define NBPF_CHAN_CFG_DAD 0x200000 /* Destination ADdress counting: 0: increment, 1: fixed */ #define NBPF_CHAN_CFG_TM 0x400000 /* Transfer Mode: 0: single, 1: block TM */ #define NBPF_CHAN_CFG_DEM 0x1000000 /* DMAEND interrupt Mask */ #define NBPF_CHAN_CFG_TCM 0x2000000 /* DMATCO interrupt Mask */ #define NBPF_CHAN_CFG_SBE 0x8000000 /* Sweep Buffer Enable */ #define NBPF_CHAN_CFG_RSEL 0x10000000 /* RM: Register Set sELect */ #define NBPF_CHAN_CFG_RSW 0x20000000 /* RM: Register Select sWitch */ #define NBPF_CHAN_CFG_REN 0x40000000 /* RM: Register Set Enable */ #define NBPF_CHAN_CFG_DMS 0x80000000 /* 0: register mode (RM), 1: link mode (LM) */ #define NBPF_CHAN_NXLA 0x38 #define NBPF_CHAN_CRLA 0x3c /* Link Header field */ #define NBPF_HEADER_LV 1 #define NBPF_HEADER_LE 2 #define NBPF_HEADER_WBD 4 #define NBPF_HEADER_DIM 8 #define NBPF_CTRL 0x300 #define NBPF_CTRL_PR 1 /* 0: fixed priority, 1: round robin */ #define NBPF_CTRL_LVINT 2 /* DMAEND and DMAERR signalling: 0: pulse, 1: level */ #define NBPF_DSTAT_ER 0x314 #define NBPF_DSTAT_END 0x318 #define NBPF_DMA_BUSWIDTHS \ (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \ BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \ BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)) struct nbpf_config { int num_channels; int buffer_size; }; /* * We've got 3 types of objects, used to describe DMA transfers: * 1. high-level descriptor, containing a struct dma_async_tx_descriptor object * in it, used to communicate with the user * 2. hardware DMA link descriptors, that we pass to DMAC for DMA transfer * queuing, these must be DMAable, using either the streaming DMA API or * allocated from coherent memory - one per SG segment * 3. one per SG segment descriptors, used to manage HW link descriptors from * (2). They do not have to be DMAable. They can either be (a) allocated * together with link descriptors as mixed (DMA / CPU) objects, or (b) * separately. Even if allocated separately it would be best to link them * to link descriptors once during channel resource allocation and always * use them as a single object. * Therefore for both cases (a) and (b) at run-time objects (2) and (3) shall be * treated as a single SG segment descriptor. */ struct nbpf_link_reg { u32 header; u32 src_addr; u32 dst_addr; u32 transaction_size; u32 config; u32 interval; u32 extension; u32 next; } __packed; struct nbpf_device; struct nbpf_channel; struct nbpf_desc; struct nbpf_link_desc { struct nbpf_link_reg *hwdesc; dma_addr_t hwdesc_dma_addr; struct nbpf_desc *desc; struct list_head node; }; /** * struct nbpf_desc - DMA transfer descriptor * @async_tx: dmaengine object * @user_wait: waiting for a user ack * @length: total transfer length * @sg: list of hardware descriptors, represented by struct nbpf_link_desc * @node: member in channel descriptor lists */ struct nbpf_desc { struct dma_async_tx_descriptor async_tx; bool user_wait; size_t length; struct nbpf_channel *chan; struct list_head sg; struct list_head node; }; /* Take a wild guess: allocate 4 segments per descriptor */ #define NBPF_SEGMENTS_PER_DESC 4 #define NBPF_DESCS_PER_PAGE ((PAGE_SIZE - sizeof(struct list_head)) / \ (sizeof(struct nbpf_desc) + \ NBPF_SEGMENTS_PER_DESC * \ (sizeof(struct nbpf_link_desc) + sizeof(struct nbpf_link_reg)))) #define NBPF_SEGMENTS_PER_PAGE (NBPF_SEGMENTS_PER_DESC * NBPF_DESCS_PER_PAGE) struct nbpf_desc_page { struct list_head node; struct nbpf_desc desc[NBPF_DESCS_PER_PAGE]; struct nbpf_link_desc ldesc[NBPF_SEGMENTS_PER_PAGE]; struct nbpf_link_reg hwdesc[NBPF_SEGMENTS_PER_PAGE]; }; /** * struct nbpf_channel - one DMAC channel * @dma_chan: standard dmaengine channel object * @base: register address base * @nbpf: DMAC * @name: IRQ name * @irq: IRQ number * @slave_addr: address for slave DMA * @slave_width:slave data size in bytes * @slave_burst:maximum slave burst size in bytes * @terminal: DMA terminal, assigned to this channel * @dmarq_cfg: DMA request line configuration - high / low, edge / level for NBPF_CHAN_CFG * @flags: configuration flags from DT * @lock: protect descriptor lists * @free_links: list of free link descriptors * @free: list of free descriptors * @queued: list of queued descriptors * @active: list of descriptors, scheduled for processing * @done: list of completed descriptors, waiting post-processing * @desc_page: list of additionally allocated descriptor pages - if any */ struct nbpf_channel { struct dma_chan dma_chan; struct tasklet_struct tasklet; void __iomem *base; struct nbpf_device *nbpf; char name[16]; int irq; dma_addr_t slave_src_addr; size_t slave_src_width; size_t slave_src_burst; dma_addr_t slave_dst_addr; size_t slave_dst_width; size_t slave_dst_burst; unsigned int terminal; u32 dmarq_cfg; unsigned long flags; spinlock_t lock; struct list_head free_links; struct list_head free; struct list_head queued; struct list_head active; struct list_head done; struct list_head desc_page; struct nbpf_desc *running; bool paused; }; struct nbpf_device { struct dma_device dma_dev; void __iomem *base; struct clk *clk; const struct nbpf_config *config; struct nbpf_channel chan[]; }; enum nbpf_model { NBPF1B4, NBPF1B8, NBPF1B16, NBPF4B4, NBPF4B8, NBPF4B16, NBPF8B4, NBPF8B8, NBPF8B16, }; static struct nbpf_config nbpf_cfg[] = { [NBPF1B4] = { .num_channels = 1, .buffer_size = 4, }, [NBPF1B8] = { .num_channels = 1, .buffer_size = 8, }, [NBPF1B16] = { .num_channels = 1, .buffer_size = 16, }, [NBPF4B4] = { .num_channels = 4, .buffer_size = 4, }, [NBPF4B8] = { .num_channels = 4, .buffer_size = 8, }, [NBPF4B16] = { .num_channels = 4, .buffer_size = 16, }, [NBPF8B4] = { .num_channels = 8, .buffer_size = 4, }, [NBPF8B8] = { .num_channels = 8, .buffer_size = 8, }, [NBPF8B16] = { .num_channels = 8, .buffer_size = 16, }, }; #define nbpf_to_chan(d) container_of(d, struct nbpf_channel, dma_chan) /* * dmaengine drivers seem to have a lot in common and instead of sharing more * code, they reimplement those common algorithms independently. In this driver * we try to separate the hardware-specific part from the (largely) generic * part. This improves code readability and makes it possible in the future to * reuse the generic code in form of a helper library. That generic code should * be suitable for various DMA controllers, using transfer descriptors in RAM * and pushing one SG list at a time to the DMA controller. */ /* Hardware-specific part */ static inline u32 nbpf_chan_read(struct nbpf_channel *chan, unsigned int offset) { u32 data = ioread32(chan->base + offset); dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n", __func__, chan->base, offset, data); return data; } static inline void nbpf_chan_write(struct nbpf_channel *chan, unsigned int offset, u32 data) { iowrite32(data, chan->base + offset); dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n", __func__, chan->base, offset, data); } static inline u32 nbpf_read(struct nbpf_device *nbpf, unsigned int offset) { u32 data = ioread32(nbpf->base + offset); dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n", __func__, nbpf->base, offset, data); return data; } static inline void nbpf_write(struct nbpf_device *nbpf, unsigned int offset, u32 data) { iowrite32(data, nbpf->base + offset); dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n", __func__, nbpf->base, offset, data); } static void nbpf_chan_halt(struct nbpf_channel *chan) { nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN); } static bool nbpf_status_get(struct nbpf_channel *chan) { u32 status = nbpf_read(chan->nbpf, NBPF_DSTAT_END); return status & BIT(chan - chan->nbpf->chan); } static void nbpf_status_ack(struct nbpf_channel *chan) { nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREND); } static u32 nbpf_error_get(struct nbpf_device *nbpf) { return nbpf_read(nbpf, NBPF_DSTAT_ER); } static struct nbpf_channel *nbpf_error_get_channel(struct nbpf_device *nbpf, u32 error) { return nbpf->chan + __ffs(error); } static void nbpf_error_clear(struct nbpf_channel *chan) { u32 status; int i; /* Stop the channel, make sure DMA has been aborted */ nbpf_chan_halt(chan); for (i = 1000; i; i--) { status = nbpf_chan_read(chan, NBPF_CHAN_STAT); if (!(status & NBPF_CHAN_STAT_TACT)) break; cpu_relax(); } if (!i) dev_err(chan->dma_chan.device->dev, "%s(): abort timeout, channel status 0x%x\n", __func__, status); nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SWRST); } static int nbpf_start(struct nbpf_desc *desc) { struct nbpf_channel *chan = desc->chan; struct nbpf_link_desc *ldesc = list_first_entry(&desc->sg, struct nbpf_link_desc, node); nbpf_chan_write(chan, NBPF_CHAN_NXLA, (u32)ldesc->hwdesc_dma_addr); nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETEN | NBPF_CHAN_CTRL_CLRSUS); chan->paused = false; /* Software trigger MEMCPY - only MEMCPY uses the block mode */ if (ldesc->hwdesc->config & NBPF_CHAN_CFG_TM) nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_STG); dev_dbg(chan->nbpf->dma_dev.dev, "%s(): next 0x%x, cur 0x%x\n", __func__, nbpf_chan_read(chan, NBPF_CHAN_NXLA), nbpf_chan_read(chan, NBPF_CHAN_CRLA)); return 0; } static void nbpf_chan_prepare(struct nbpf_channel *chan) { chan->dmarq_cfg = (chan->flags & NBPF_SLAVE_RQ_HIGH ? NBPF_CHAN_CFG_HIEN : 0) | (chan->flags & NBPF_SLAVE_RQ_LOW ? NBPF_CHAN_CFG_LOEN : 0) | (chan->flags & NBPF_SLAVE_RQ_LEVEL ? NBPF_CHAN_CFG_LVL | (NBPF_CHAN_CFG_AM & 0x200) : 0) | chan->terminal; } static void nbpf_chan_prepare_default(struct nbpf_channel *chan) { /* Don't output DMAACK */ chan->dmarq_cfg = NBPF_CHAN_CFG_AM & 0x400; chan->terminal = 0; chan->flags = 0; } static void nbpf_chan_configure(struct nbpf_channel *chan) { /* * We assume, that only the link mode and DMA request line configuration * have to be set in the configuration register manually. Dynamic * per-transfer configuration will be loaded from transfer descriptors. */ nbpf_chan_write(chan, NBPF_CHAN_CFG, NBPF_CHAN_CFG_DMS | chan->dmarq_cfg); } static u32 nbpf_xfer_ds(struct nbpf_device *nbpf, size_t size) { /* Maximum supported bursts depend on the buffer size */ return min_t(int, __ffs(size), ilog2(nbpf->config->buffer_size * 8)); } static size_t nbpf_xfer_size(struct nbpf_device *nbpf, enum dma_slave_buswidth width, u32 burst) { size_t size; if (!burst) burst = 1; switch (width) { case DMA_SLAVE_BUSWIDTH_8_BYTES: size = 8 * burst; break; case DMA_SLAVE_BUSWIDTH_4_BYTES: size = 4 * burst; break; case DMA_SLAVE_BUSWIDTH_2_BYTES: size = 2 * burst; break; default: pr_warn("%s(): invalid bus width %u\n", __func__, width); case DMA_SLAVE_BUSWIDTH_1_BYTE: size = burst; } return nbpf_xfer_ds(nbpf, size); } /* * We need a way to recognise slaves, whose data is sent "raw" over the bus, * i.e. it isn't known in advance how many bytes will be received. Therefore * the slave driver has to provide a "large enough" buffer and either read the * buffer, when it is full, or detect, that some data has arrived, then wait for * a timeout, if no more data arrives - receive what's already there. We want to * handle such slaves in a special way to allow an optimised mode for other * users, for whom the amount of data is known in advance. So far there's no way * to recognise such slaves. We use a data-width check to distinguish between * the SD host and the PL011 UART. */ static int nbpf_prep_one(struct nbpf_link_desc *ldesc, enum dma_transfer_direction direction, dma_addr_t src, dma_addr_t dst, size_t size, bool last) { struct nbpf_link_reg *hwdesc = ldesc->hwdesc; struct nbpf_desc *desc = ldesc->desc; struct nbpf_channel *chan = desc->chan; struct device *dev = chan->dma_chan.device->dev; size_t mem_xfer, slave_xfer; bool can_burst; hwdesc->header = NBPF_HEADER_WBD | NBPF_HEADER_LV | (last ? NBPF_HEADER_LE : 0); hwdesc->src_addr = src; hwdesc->dst_addr = dst; hwdesc->transaction_size = size; /* * set config: SAD, DAD, DDS, SDS, etc. * Note on transfer sizes: the DMAC can perform unaligned DMA transfers, * but it is important to have transaction size a multiple of both * receiver and transmitter transfer sizes. It is also possible to use * different RAM and device transfer sizes, and it does work well with * some devices, e.g. with V08R07S01E SD host controllers, which can use * 128 byte transfers. But this doesn't work with other devices, * especially when the transaction size is unknown. This is the case, * e.g. with serial drivers like amba-pl011.c. For reception it sets up * the transaction size of 4K and if fewer bytes are received, it * pauses DMA and reads out data received via DMA as well as those left * in the Rx FIFO. For this to work with the RAM side using burst * transfers we enable the SBE bit and terminate the transfer in our * DMA_PAUSE handler. */ mem_xfer = nbpf_xfer_ds(chan->nbpf, size); switch (direction) { case DMA_DEV_TO_MEM: can_burst = chan->slave_src_width >= 3; slave_xfer = min(mem_xfer, can_burst ? chan->slave_src_burst : chan->slave_src_width); /* * Is the slave narrower than 64 bits, i.e. isn't using the full * bus width and cannot use bursts? */ if (mem_xfer > chan->slave_src_burst && !can_burst) mem_xfer = chan->slave_src_burst; /* Device-to-RAM DMA is unreliable without REQD set */ hwdesc->config = NBPF_CHAN_CFG_SAD | (NBPF_CHAN_CFG_DDS & (mem_xfer << 16)) | (NBPF_CHAN_CFG_SDS & (slave_xfer << 12)) | NBPF_CHAN_CFG_REQD | NBPF_CHAN_CFG_SBE; break; case DMA_MEM_TO_DEV: slave_xfer = min(mem_xfer, chan->slave_dst_width >= 3 ? chan->slave_dst_burst : chan->slave_dst_width); hwdesc->config = NBPF_CHAN_CFG_DAD | (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) | (NBPF_CHAN_CFG_DDS & (slave_xfer << 16)) | NBPF_CHAN_CFG_REQD; break; case DMA_MEM_TO_MEM: hwdesc->config = NBPF_CHAN_CFG_TCM | NBPF_CHAN_CFG_TM | (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) | (NBPF_CHAN_CFG_DDS & (mem_xfer << 16)); break; default: return -EINVAL; } hwdesc->config |= chan->dmarq_cfg | (last ? 0 : NBPF_CHAN_CFG_DEM) | NBPF_CHAN_CFG_DMS; dev_dbg(dev, "%s(): desc @ %pad: hdr 0x%x, cfg 0x%x, %zu @ %pad -> %pad\n", __func__, &ldesc->hwdesc_dma_addr, hwdesc->header, hwdesc->config, size, &src, &dst); dma_sync_single_for_device(dev, ldesc->hwdesc_dma_addr, sizeof(*hwdesc), DMA_TO_DEVICE); return 0; } static size_t nbpf_bytes_left(struct nbpf_channel *chan) { return nbpf_chan_read(chan, NBPF_CHAN_CUR_TR_BYTE); } static void nbpf_configure(struct nbpf_device *nbpf) { nbpf_write(nbpf, NBPF_CTRL, NBPF_CTRL_LVINT); } static void nbpf_pause(struct nbpf_channel *chan) { nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETSUS); /* See comment in nbpf_prep_one() */ nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN); } /* Generic part */ /* DMA ENGINE functions */ static void nbpf_issue_pending(struct dma_chan *dchan) { struct nbpf_channel *chan = nbpf_to_chan(dchan); unsigned long flags; dev_dbg(dchan->device->dev, "Entry %s()\n", __func__); spin_lock_irqsave(&chan->lock, flags); if (list_empty(&chan->queued)) goto unlock; list_splice_tail_init(&chan->queued, &chan->active); if (!chan->running) { struct nbpf_desc *desc = list_first_entry(&chan->active, struct nbpf_desc, node); if (!nbpf_start(desc)) chan->running = desc; } unlock: spin_unlock_irqrestore(&chan->lock, flags); } static enum dma_status nbpf_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *state) { struct nbpf_channel *chan = nbpf_to_chan(dchan); enum dma_status status = dma_cookie_status(dchan, cookie, state); if (state) { dma_cookie_t running; unsigned long flags; spin_lock_irqsave(&chan->lock, flags); running = chan->running ? chan->running->async_tx.cookie : -EINVAL; if (cookie == running) { state->residue = nbpf_bytes_left(chan); dev_dbg(dchan->device->dev, "%s(): residue %u\n", __func__, state->residue); } else if (status == DMA_IN_PROGRESS) { struct nbpf_desc *desc; bool found = false; list_for_each_entry(desc, &chan->active, node) if (desc->async_tx.cookie == cookie) { found = true; break; } if (!found) list_for_each_entry(desc, &chan->queued, node) if (desc->async_tx.cookie == cookie) { found = true; break; } state->residue = found ? desc->length : 0; } spin_unlock_irqrestore(&chan->lock, flags); } if (chan->paused) status = DMA_PAUSED; return status; } static dma_cookie_t nbpf_tx_submit(struct dma_async_tx_descriptor *tx) { struct nbpf_desc *desc = container_of(tx, struct nbpf_desc, async_tx); struct nbpf_channel *chan = desc->chan; unsigned long flags; dma_cookie_t cookie; spin_lock_irqsave(&chan->lock, flags); cookie = dma_cookie_assign(tx); list_add_tail(&desc->node, &chan->queued); spin_unlock_irqrestore(&chan->lock, flags); dev_dbg(chan->dma_chan.device->dev, "Entry %s(%d)\n", __func__, cookie); return cookie; } static int nbpf_desc_page_alloc(struct nbpf_channel *chan) { struct dma_chan *dchan = &chan->dma_chan; struct nbpf_desc_page *dpage = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA); struct nbpf_link_desc *ldesc; struct nbpf_link_reg *hwdesc; struct nbpf_desc *desc; LIST_HEAD(head); LIST_HEAD(lhead); int i; struct device *dev = dchan->device->dev; if (!dpage) return -ENOMEM; dev_dbg(dev, "%s(): alloc %lu descriptors, %lu segments, total alloc %zu\n", __func__, NBPF_DESCS_PER_PAGE, NBPF_SEGMENTS_PER_PAGE, sizeof(*dpage)); for (i = 0, ldesc = dpage->ldesc, hwdesc = dpage->hwdesc; i < ARRAY_SIZE(dpage->ldesc); i++, ldesc++, hwdesc++) { ldesc->hwdesc = hwdesc; list_add_tail(&ldesc->node, &lhead); ldesc->hwdesc_dma_addr = dma_map_single(dchan->device->dev, hwdesc, sizeof(*hwdesc), DMA_TO_DEVICE); dev_dbg(dev, "%s(): mapped 0x%p to %pad\n", __func__, hwdesc, &ldesc->hwdesc_dma_addr); } for (i = 0, desc = dpage->desc; i < ARRAY_SIZE(dpage->desc); i++, desc++) { dma_async_tx_descriptor_init(&desc->async_tx, dchan); desc->async_tx.tx_submit = nbpf_tx_submit; desc->chan = chan; INIT_LIST_HEAD(&desc->sg); list_add_tail(&desc->node, &head); } /* * This function cannot be called from interrupt context, so, no need to * save flags */ spin_lock_irq(&chan->lock); list_splice_tail(&lhead, &chan->free_links); list_splice_tail(&head, &chan->free); list_add(&dpage->node, &chan->desc_page); spin_unlock_irq(&chan->lock); return ARRAY_SIZE(dpage->desc); } static void nbpf_desc_put(struct nbpf_desc *desc) { struct nbpf_channel *chan = desc->chan; struct nbpf_link_desc *ldesc, *tmp; unsigned long flags; spin_lock_irqsave(&chan->lock, flags); list_for_each_entry_safe(ldesc, tmp, &desc->sg, node) list_move(&ldesc->node, &chan->free_links); list_add(&desc->node, &chan->free); spin_unlock_irqrestore(&chan->lock, flags); } static void nbpf_scan_acked(struct nbpf_channel *chan) { struct nbpf_desc *desc, *tmp; unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&chan->lock, flags); list_for_each_entry_safe(desc, tmp, &chan->done, node) if (async_tx_test_ack(&desc->async_tx) && desc->user_wait) { list_move(&desc->node, &head); desc->user_wait = false; } spin_unlock_irqrestore(&chan->lock, flags); list_for_each_entry_safe(desc, tmp, &head, node) { list_del(&desc->node); nbpf_desc_put(desc); } } /* * We have to allocate descriptors with the channel lock dropped. This means, * before we re-acquire the lock buffers can be taken already, so we have to * re-check after re-acquiring the lock and possibly retry, if buffers are gone * again. */ static struct nbpf_desc *nbpf_desc_get(struct nbpf_channel *chan, size_t len) { struct nbpf_desc *desc = NULL; struct nbpf_link_desc *ldesc, *prev = NULL; nbpf_scan_acked(chan); spin_lock_irq(&chan->lock); do { int i = 0, ret; if (list_empty(&chan->free)) { /* No more free descriptors */ spin_unlock_irq(&chan->lock); ret = nbpf_desc_page_alloc(chan); if (ret < 0) return NULL; spin_lock_irq(&chan->lock); continue; } desc = list_first_entry(&chan->free, struct nbpf_desc, node); list_del(&desc->node); do { if (list_empty(&chan->free_links)) { /* No more free link descriptors */ spin_unlock_irq(&chan->lock); ret = nbpf_desc_page_alloc(chan); if (ret < 0) { nbpf_desc_put(desc); return NULL; } spin_lock_irq(&chan->lock); continue; } ldesc = list_first_entry(&chan->free_links, struct nbpf_link_desc, node); ldesc->desc = desc; if (prev) prev->hwdesc->next = (u32)ldesc->hwdesc_dma_addr; prev = ldesc; list_move_tail(&ldesc->node, &desc->sg); i++; } while (i < len); } while (!desc); prev->hwdesc->next = 0; spin_unlock_irq(&chan->lock); return desc; } static void nbpf_chan_idle(struct nbpf_channel *chan) { struct nbpf_desc *desc, *tmp; unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&chan->lock, flags); list_splice_init(&chan->done, &head); list_splice_init(&chan->active, &head); list_splice_init(&chan->queued, &head); chan->running = NULL; spin_unlock_irqrestore(&chan->lock, flags); list_for_each_entry_safe(desc, tmp, &head, node) { dev_dbg(chan->nbpf->dma_dev.dev, "%s(): force-free desc %p cookie %d\n", __func__, desc, desc->async_tx.cookie); list_del(&desc->node); nbpf_desc_put(desc); } } static int nbpf_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, unsigned long arg) { struct nbpf_channel *chan = nbpf_to_chan(dchan); struct dma_slave_config *config; dev_dbg(dchan->device->dev, "Entry %s(%d)\n", __func__, cmd); switch (cmd) { case DMA_TERMINATE_ALL: dev_dbg(dchan->device->dev, "Terminating\n"); nbpf_chan_halt(chan); nbpf_chan_idle(chan); break; case DMA_SLAVE_CONFIG: if (!arg) return -EINVAL; config = (struct dma_slave_config *)arg; /* * We could check config->slave_id to match chan->terminal here, * but with DT they would be coming from the same source, so * such a check would be superflous */ chan->slave_dst_addr = config->dst_addr; chan->slave_dst_width = nbpf_xfer_size(chan->nbpf, config->dst_addr_width, 1); chan->slave_dst_burst = nbpf_xfer_size(chan->nbpf, config->dst_addr_width, config->dst_maxburst); chan->slave_src_addr = config->src_addr; chan->slave_src_width = nbpf_xfer_size(chan->nbpf, config->src_addr_width, 1); chan->slave_src_burst = nbpf_xfer_size(chan->nbpf, config->src_addr_width, config->src_maxburst); break; case DMA_PAUSE: chan->paused = true; nbpf_pause(chan); break; default: return -ENXIO; } return 0; } static struct dma_async_tx_descriptor *nbpf_prep_sg(struct nbpf_channel *chan, struct scatterlist *src_sg, struct scatterlist *dst_sg, size_t len, enum dma_transfer_direction direction, unsigned long flags) { struct nbpf_link_desc *ldesc; struct scatterlist *mem_sg; struct nbpf_desc *desc; bool inc_src, inc_dst; size_t data_len = 0; int i = 0; switch (direction) { case DMA_DEV_TO_MEM: mem_sg = dst_sg; inc_src = false; inc_dst = true; break; case DMA_MEM_TO_DEV: mem_sg = src_sg; inc_src = true; inc_dst = false; break; default: case DMA_MEM_TO_MEM: mem_sg = src_sg; inc_src = true; inc_dst = true; } desc = nbpf_desc_get(chan, len); if (!desc) return NULL; desc->async_tx.flags = flags; desc->async_tx.cookie = -EBUSY; desc->user_wait = false; /* * This is a private descriptor list, and we own the descriptor. No need * to lock. */ list_for_each_entry(ldesc, &desc->sg, node) { int ret = nbpf_prep_one(ldesc, direction, sg_dma_address(src_sg), sg_dma_address(dst_sg), sg_dma_len(mem_sg), i == len - 1); if (ret < 0) { nbpf_desc_put(desc); return NULL; } data_len += sg_dma_len(mem_sg); if (inc_src) src_sg = sg_next(src_sg); if (inc_dst) dst_sg = sg_next(dst_sg); mem_sg = direction == DMA_DEV_TO_MEM ? dst_sg : src_sg; i++; } desc->length = data_len; /* The user has to return the descriptor to us ASAP via .tx_submit() */ return &desc->async_tx; } static struct dma_async_tx_descriptor *nbpf_prep_memcpy( struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src, size_t len, unsigned long flags) { struct nbpf_channel *chan = nbpf_to_chan(dchan); struct scatterlist dst_sg; struct scatterlist src_sg; sg_init_table(&dst_sg, 1); sg_init_table(&src_sg, 1); sg_dma_address(&dst_sg) = dst; sg_dma_address(&src_sg) = src; sg_dma_len(&dst_sg) = len; sg_dma_len(&src_sg) = len; dev_dbg(dchan->device->dev, "%s(): %zu @ %pad -> %pad\n", __func__, len, &src, &dst); return nbpf_prep_sg(chan, &src_sg, &dst_sg, 1, DMA_MEM_TO_MEM, flags); } static struct dma_async_tx_descriptor *nbpf_prep_memcpy_sg( struct dma_chan *dchan, struct scatterlist *dst_sg, unsigned int dst_nents, struct scatterlist *src_sg, unsigned int src_nents, unsigned long flags) { struct nbpf_channel *chan = nbpf_to_chan(dchan); if (dst_nents != src_nents) return NULL; return nbpf_prep_sg(chan, src_sg, dst_sg, src_nents, DMA_MEM_TO_MEM, flags); } static struct dma_async_tx_descriptor *nbpf_prep_slave_sg( struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, unsigned long flags, void *context) { struct nbpf_channel *chan = nbpf_to_chan(dchan); struct scatterlist slave_sg; dev_dbg(dchan->device->dev, "Entry %s()\n", __func__); sg_init_table(&slave_sg, 1); switch (direction) { case DMA_MEM_TO_DEV: sg_dma_address(&slave_sg) = chan->slave_dst_addr; return nbpf_prep_sg(chan, sgl, &slave_sg, sg_len, direction, flags); case DMA_DEV_TO_MEM: sg_dma_address(&slave_sg) = chan->slave_src_addr; return nbpf_prep_sg(chan, &slave_sg, sgl, sg_len, direction, flags); default: return NULL; } } static int nbpf_alloc_chan_resources(struct dma_chan *dchan) { struct nbpf_channel *chan = nbpf_to_chan(dchan); int ret; INIT_LIST_HEAD(&chan->free); INIT_LIST_HEAD(&chan->free_links); INIT_LIST_HEAD(&chan->queued); INIT_LIST_HEAD(&chan->active); INIT_LIST_HEAD(&chan->done); ret = nbpf_desc_page_alloc(chan); if (ret < 0) return ret; dev_dbg(dchan->device->dev, "Entry %s(): terminal %u\n", __func__, chan->terminal); nbpf_chan_configure(chan); return ret; } static void nbpf_free_chan_resources(struct dma_chan *dchan) { struct nbpf_channel *chan = nbpf_to_chan(dchan); struct nbpf_desc_page *dpage, *tmp; dev_dbg(dchan->device->dev, "Entry %s()\n", __func__); nbpf_chan_halt(chan); nbpf_chan_idle(chan); /* Clean up for if a channel is re-used for MEMCPY after slave DMA */ nbpf_chan_prepare_default(chan); list_for_each_entry_safe(dpage, tmp, &chan->desc_page, node) { struct nbpf_link_desc *ldesc; int i; list_del(&dpage->node); for (i = 0, ldesc = dpage->ldesc; i < ARRAY_SIZE(dpage->ldesc); i++, ldesc++) dma_unmap_single(dchan->device->dev, ldesc->hwdesc_dma_addr, sizeof(*ldesc->hwdesc), DMA_TO_DEVICE); free_page((unsigned long)dpage); } } static int nbpf_slave_caps(struct dma_chan *dchan, struct dma_slave_caps *caps) { caps->src_addr_widths = NBPF_DMA_BUSWIDTHS; caps->dstn_addr_widths = NBPF_DMA_BUSWIDTHS; caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); caps->cmd_pause = false; caps->cmd_terminate = true; return 0; } static struct dma_chan *nbpf_of_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct nbpf_device *nbpf = ofdma->of_dma_data; struct dma_chan *dchan; struct nbpf_channel *chan; if (dma_spec->args_count != 2) return NULL; dchan = dma_get_any_slave_channel(&nbpf->dma_dev); if (!dchan) return NULL; dev_dbg(dchan->device->dev, "Entry %s(%s)\n", __func__, dma_spec->np->name); chan = nbpf_to_chan(dchan); chan->terminal = dma_spec->args[0]; chan->flags = dma_spec->args[1]; nbpf_chan_prepare(chan); nbpf_chan_configure(chan); return dchan; } static void nbpf_chan_tasklet(unsigned long data) { struct nbpf_channel *chan = (struct nbpf_channel *)data; struct nbpf_desc *desc, *tmp; dma_async_tx_callback callback; void *param; while (!list_empty(&chan->done)) { bool found = false, must_put, recycling = false; spin_lock_irq(&chan->lock); list_for_each_entry_safe(desc, tmp, &chan->done, node) { if (!desc->user_wait) { /* Newly completed descriptor, have to process */ found = true; break; } else if (async_tx_test_ack(&desc->async_tx)) { /* * This descriptor was waiting for a user ACK, * it can be recycled now. */ list_del(&desc->node); spin_unlock_irq(&chan->lock); nbpf_desc_put(desc); recycling = true; break; } } if (recycling) continue; if (!found) { /* This can happen if TERMINATE_ALL has been called */ spin_unlock_irq(&chan->lock); break; } dma_cookie_complete(&desc->async_tx); /* * With released lock we cannot dereference desc, maybe it's * still on the "done" list */ if (async_tx_test_ack(&desc->async_tx)) { list_del(&desc->node); must_put = true; } else { desc->user_wait = true; must_put = false; } callback = desc->async_tx.callback; param = desc->async_tx.callback_param; /* ack and callback completed descriptor */ spin_unlock_irq(&chan->lock); if (callback) callback(param); if (must_put) nbpf_desc_put(desc); } } static irqreturn_t nbpf_chan_irq(int irq, void *dev) { struct nbpf_channel *chan = dev; bool done = nbpf_status_get(chan); struct nbpf_desc *desc; irqreturn_t ret; bool bh = false; if (!done) return IRQ_NONE; nbpf_status_ack(chan); dev_dbg(&chan->dma_chan.dev->device, "%s()\n", __func__); spin_lock(&chan->lock); desc = chan->running; if (WARN_ON(!desc)) { ret = IRQ_NONE; goto unlock; } else { ret = IRQ_HANDLED; bh = true; } list_move_tail(&desc->node, &chan->done); chan->running = NULL; if (!list_empty(&chan->active)) { desc = list_first_entry(&chan->active, struct nbpf_desc, node); if (!nbpf_start(desc)) chan->running = desc; } unlock: spin_unlock(&chan->lock); if (bh) tasklet_schedule(&chan->tasklet); return ret; } static irqreturn_t nbpf_err_irq(int irq, void *dev) { struct nbpf_device *nbpf = dev; u32 error = nbpf_error_get(nbpf); dev_warn(nbpf->dma_dev.dev, "DMA error IRQ %u\n", irq); if (!error) return IRQ_NONE; do { struct nbpf_channel *chan = nbpf_error_get_channel(nbpf, error); /* On error: abort all queued transfers, no callback */ nbpf_error_clear(chan); nbpf_chan_idle(chan); error = nbpf_error_get(nbpf); } while (error); return IRQ_HANDLED; } static int nbpf_chan_probe(struct nbpf_device *nbpf, int n) { struct dma_device *dma_dev = &nbpf->dma_dev; struct nbpf_channel *chan = nbpf->chan + n; int ret; chan->nbpf = nbpf; chan->base = nbpf->base + NBPF_REG_CHAN_OFFSET + NBPF_REG_CHAN_SIZE * n; INIT_LIST_HEAD(&chan->desc_page); spin_lock_init(&chan->lock); chan->dma_chan.device = dma_dev; dma_cookie_init(&chan->dma_chan); nbpf_chan_prepare_default(chan); dev_dbg(dma_dev->dev, "%s(): channel %d: -> %p\n", __func__, n, chan->base); snprintf(chan->name, sizeof(chan->name), "nbpf %d", n); tasklet_init(&chan->tasklet, nbpf_chan_tasklet, (unsigned long)chan); ret = devm_request_irq(dma_dev->dev, chan->irq, nbpf_chan_irq, IRQF_SHARED, chan->name, chan); if (ret < 0) return ret; /* Add the channel to DMA device channel list */ list_add_tail(&chan->dma_chan.device_node, &dma_dev->channels); return 0; } static const struct of_device_id nbpf_match[] = { {.compatible = "renesas,nbpfaxi64dmac1b4", .data = &nbpf_cfg[NBPF1B4]}, {.compatible = "renesas,nbpfaxi64dmac1b8", .data = &nbpf_cfg[NBPF1B8]}, {.compatible = "renesas,nbpfaxi64dmac1b16", .data = &nbpf_cfg[NBPF1B16]}, {.compatible = "renesas,nbpfaxi64dmac4b4", .data = &nbpf_cfg[NBPF4B4]}, {.compatible = "renesas,nbpfaxi64dmac4b8", .data = &nbpf_cfg[NBPF4B8]}, {.compatible = "renesas,nbpfaxi64dmac4b16", .data = &nbpf_cfg[NBPF4B16]}, {.compatible = "renesas,nbpfaxi64dmac8b4", .data = &nbpf_cfg[NBPF8B4]}, {.compatible = "renesas,nbpfaxi64dmac8b8", .data = &nbpf_cfg[NBPF8B8]}, {.compatible = "renesas,nbpfaxi64dmac8b16", .data = &nbpf_cfg[NBPF8B16]}, {} }; MODULE_DEVICE_TABLE(of, nbpf_match); static int nbpf_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; const struct of_device_id *of_id = of_match_device(nbpf_match, dev); struct device_node *np = dev->of_node; struct nbpf_device *nbpf; struct dma_device *dma_dev; struct resource *iomem, *irq_res; const struct nbpf_config *cfg; int num_channels; int ret, irq, eirq, i; int irqbuf[9] /* maximum 8 channels + error IRQ */; unsigned int irqs = 0; BUILD_BUG_ON(sizeof(struct nbpf_desc_page) > PAGE_SIZE); /* DT only */ if (!np || !of_id || !of_id->data) return -ENODEV; cfg = of_id->data; num_channels = cfg->num_channels; nbpf = devm_kzalloc(dev, sizeof(*nbpf) + num_channels * sizeof(nbpf->chan[0]), GFP_KERNEL); if (!nbpf) { dev_err(dev, "Memory allocation failed\n"); return -ENOMEM; } dma_dev = &nbpf->dma_dev; dma_dev->dev = dev; iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); nbpf->base = devm_ioremap_resource(dev, iomem); if (IS_ERR(nbpf->base)) return PTR_ERR(nbpf->base); nbpf->clk = devm_clk_get(dev, NULL); if (IS_ERR(nbpf->clk)) return PTR_ERR(nbpf->clk); nbpf->config = cfg; for (i = 0; irqs < ARRAY_SIZE(irqbuf); i++) { irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, i); if (!irq_res) break; for (irq = irq_res->start; irq <= irq_res->end; irq++, irqs++) irqbuf[irqs] = irq; } /* * 3 IRQ resource schemes are supported: * 1. 1 shared IRQ for error and all channels * 2. 2 IRQs: one for error and one shared for all channels * 3. 1 IRQ for error and an own IRQ for each channel */ if (irqs != 1 && irqs != 2 && irqs != num_channels + 1) return -ENXIO; if (irqs == 1) { eirq = irqbuf[0]; for (i = 0; i <= num_channels; i++) nbpf->chan[i].irq = irqbuf[0]; } else { eirq = platform_get_irq_byname(pdev, "error"); if (eirq < 0) return eirq; if (irqs == num_channels + 1) { struct nbpf_channel *chan; for (i = 0, chan = nbpf->chan; i <= num_channels; i++, chan++) { /* Skip the error IRQ */ if (irqbuf[i] == eirq) i++; chan->irq = irqbuf[i]; } if (chan != nbpf->chan + num_channels) return -EINVAL; } else { /* 2 IRQs and more than one channel */ if (irqbuf[0] == eirq) irq = irqbuf[1]; else irq = irqbuf[0]; for (i = 0; i <= num_channels; i++) nbpf->chan[i].irq = irq; } } ret = devm_request_irq(dev, eirq, nbpf_err_irq, IRQF_SHARED, "dma error", nbpf); if (ret < 0) return ret; INIT_LIST_HEAD(&dma_dev->channels); /* Create DMA Channel */ for (i = 0; i < num_channels; i++) { ret = nbpf_chan_probe(nbpf, i); if (ret < 0) return ret; } dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); dma_cap_set(DMA_SG, dma_dev->cap_mask); /* Common and MEMCPY operations */ dma_dev->device_alloc_chan_resources = nbpf_alloc_chan_resources; dma_dev->device_free_chan_resources = nbpf_free_chan_resources; dma_dev->device_prep_dma_sg = nbpf_prep_memcpy_sg; dma_dev->device_prep_dma_memcpy = nbpf_prep_memcpy; dma_dev->device_tx_status = nbpf_tx_status; dma_dev->device_issue_pending = nbpf_issue_pending; dma_dev->device_slave_caps = nbpf_slave_caps; /* * If we drop support for unaligned MEMCPY buffer addresses and / or * lengths by setting * dma_dev->copy_align = 4; * then we can set transfer length to 4 bytes in nbpf_prep_one() for * DMA_MEM_TO_MEM */ /* Compulsory for DMA_SLAVE fields */ dma_dev->device_prep_slave_sg = nbpf_prep_slave_sg; dma_dev->device_control = nbpf_control; platform_set_drvdata(pdev, nbpf); ret = clk_prepare_enable(nbpf->clk); if (ret < 0) return ret; nbpf_configure(nbpf); ret = dma_async_device_register(dma_dev); if (ret < 0) goto e_clk_off; ret = of_dma_controller_register(np, nbpf_of_xlate, nbpf); if (ret < 0) goto e_dma_dev_unreg; return 0; e_dma_dev_unreg: dma_async_device_unregister(dma_dev); e_clk_off: clk_disable_unprepare(nbpf->clk); return ret; } static int nbpf_remove(struct platform_device *pdev) { struct nbpf_device *nbpf = platform_get_drvdata(pdev); of_dma_controller_free(pdev->dev.of_node); dma_async_device_unregister(&nbpf->dma_dev); clk_disable_unprepare(nbpf->clk); return 0; } static struct platform_device_id nbpf_ids[] = { {"nbpfaxi64dmac1b4", (kernel_ulong_t)&nbpf_cfg[NBPF1B4]}, {"nbpfaxi64dmac1b8", (kernel_ulong_t)&nbpf_cfg[NBPF1B8]}, {"nbpfaxi64dmac1b16", (kernel_ulong_t)&nbpf_cfg[NBPF1B16]}, {"nbpfaxi64dmac4b4", (kernel_ulong_t)&nbpf_cfg[NBPF4B4]}, {"nbpfaxi64dmac4b8", (kernel_ulong_t)&nbpf_cfg[NBPF4B8]}, {"nbpfaxi64dmac4b16", (kernel_ulong_t)&nbpf_cfg[NBPF4B16]}, {"nbpfaxi64dmac8b4", (kernel_ulong_t)&nbpf_cfg[NBPF8B4]}, {"nbpfaxi64dmac8b8", (kernel_ulong_t)&nbpf_cfg[NBPF8B8]}, {"nbpfaxi64dmac8b16", (kernel_ulong_t)&nbpf_cfg[NBPF8B16]}, {}, }; MODULE_DEVICE_TABLE(platform, nbpf_ids); #ifdef CONFIG_PM static int nbpf_runtime_suspend(struct device *dev) { struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev)); clk_disable_unprepare(nbpf->clk); return 0; } static int nbpf_runtime_resume(struct device *dev) { struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev)); return clk_prepare_enable(nbpf->clk); } #endif static const struct dev_pm_ops nbpf_pm_ops = { SET_RUNTIME_PM_OPS(nbpf_runtime_suspend, nbpf_runtime_resume, NULL) }; static struct platform_driver nbpf_driver = { .driver = { .owner = THIS_MODULE, .name = "dma-nbpf", .of_match_table = nbpf_match, .pm = &nbpf_pm_ops, }, .id_table = nbpf_ids, .probe = nbpf_probe, .remove = nbpf_remove, }; module_platform_driver(nbpf_driver); MODULE_AUTHOR("Guennadi Liakhovetski "); MODULE_DESCRIPTION("dmaengine driver for NBPFAXI64* DMACs"); MODULE_LICENSE("GPL v2");