/* * S3C24XX DMA handling * * Copyright (c) 2013 Heiko Stuebner * * based on amba-pl08x.c * * Copyright (c) 2006 ARM Ltd. * Copyright (c) 2010 ST-Ericsson SA * * Author: Peter Pearse * Author: Linus Walleij * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * * The DMA controllers in S3C24XX SoCs have a varying number of DMA signals * that can be routed to any of the 4 to 8 hardware-channels. * * Therefore on these DMA controllers the number of channels * and the number of incoming DMA signals are two totally different things. * It is usually not possible to theoretically handle all physical signals, * so a multiplexing scheme with possible denial of use is necessary. * * Open items: * - bursts */ #include #include #include #include #include #include #include #include #include #include "dmaengine.h" #include "virt-dma.h" #define MAX_DMA_CHANNELS 8 #define S3C24XX_DISRC 0x00 #define S3C24XX_DISRCC 0x04 #define S3C24XX_DISRCC_INC_INCREMENT 0 #define S3C24XX_DISRCC_INC_FIXED BIT(0) #define S3C24XX_DISRCC_LOC_AHB 0 #define S3C24XX_DISRCC_LOC_APB BIT(1) #define S3C24XX_DIDST 0x08 #define S3C24XX_DIDSTC 0x0c #define S3C24XX_DIDSTC_INC_INCREMENT 0 #define S3C24XX_DIDSTC_INC_FIXED BIT(0) #define S3C24XX_DIDSTC_LOC_AHB 0 #define S3C24XX_DIDSTC_LOC_APB BIT(1) #define S3C24XX_DIDSTC_INT_TC0 0 #define S3C24XX_DIDSTC_INT_RELOAD BIT(2) #define S3C24XX_DCON 0x10 #define S3C24XX_DCON_TC_MASK 0xfffff #define S3C24XX_DCON_DSZ_BYTE (0 << 20) #define S3C24XX_DCON_DSZ_HALFWORD (1 << 20) #define S3C24XX_DCON_DSZ_WORD (2 << 20) #define S3C24XX_DCON_DSZ_MASK (3 << 20) #define S3C24XX_DCON_DSZ_SHIFT 20 #define S3C24XX_DCON_AUTORELOAD 0 #define S3C24XX_DCON_NORELOAD BIT(22) #define S3C24XX_DCON_HWTRIG BIT(23) #define S3C24XX_DCON_HWSRC_SHIFT 24 #define S3C24XX_DCON_SERV_SINGLE 0 #define S3C24XX_DCON_SERV_WHOLE BIT(27) #define S3C24XX_DCON_TSZ_UNIT 0 #define S3C24XX_DCON_TSZ_BURST4 BIT(28) #define S3C24XX_DCON_INT BIT(29) #define S3C24XX_DCON_SYNC_PCLK 0 #define S3C24XX_DCON_SYNC_HCLK BIT(30) #define S3C24XX_DCON_DEMAND 0 #define S3C24XX_DCON_HANDSHAKE BIT(31) #define S3C24XX_DSTAT 0x14 #define S3C24XX_DSTAT_STAT_BUSY BIT(20) #define S3C24XX_DSTAT_CURRTC_MASK 0xfffff #define S3C24XX_DMASKTRIG 0x20 #define S3C24XX_DMASKTRIG_SWTRIG BIT(0) #define S3C24XX_DMASKTRIG_ON BIT(1) #define S3C24XX_DMASKTRIG_STOP BIT(2) #define S3C24XX_DMAREQSEL 0x24 #define S3C24XX_DMAREQSEL_HW BIT(0) /* * S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel * for a DMA source. Instead only specific channels are valid. * All of these SoCs have 4 physical channels and the number of request * source bits is 3. Additionally we also need 1 bit to mark the channel * as valid. * Therefore we separate the chansel element of the channel data into 4 * parts of 4 bits each, to hold the information if the channel is valid * and the hw request source to use. * * Example: * SDI is valid on channels 0, 2 and 3 - with varying hw request sources. * For it the chansel field would look like * * ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1 * ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2 * ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2 */ #define S3C24XX_CHANSEL_WIDTH 4 #define S3C24XX_CHANSEL_VALID BIT(3) #define S3C24XX_CHANSEL_REQ_MASK 7 /* * struct soc_data - vendor-specific config parameters for individual SoCs * @stride: spacing between the registers of each channel * @has_reqsel: does the controller use the newer requestselection mechanism * @has_clocks: are controllable dma-clocks present */ struct soc_data { int stride; bool has_reqsel; bool has_clocks; }; /* * enum s3c24xx_dma_chan_state - holds the virtual channel states * @S3C24XX_DMA_CHAN_IDLE: the channel is idle * @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical transport * channel and is running a transfer on it * @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical transport * channel to become available (only pertains to memcpy channels) */ enum s3c24xx_dma_chan_state { S3C24XX_DMA_CHAN_IDLE, S3C24XX_DMA_CHAN_RUNNING, S3C24XX_DMA_CHAN_WAITING, }; /* * struct s3c24xx_sg - structure containing data per sg * @src_addr: src address of sg * @dst_addr: dst address of sg * @len: transfer len in bytes * @node: node for txd's dsg_list */ struct s3c24xx_sg { dma_addr_t src_addr; dma_addr_t dst_addr; size_t len; struct list_head node; }; /* * struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor * @vd: virtual DMA descriptor * @dsg_list: list of children sg's * @at: sg currently being transfered * @width: transfer width * @disrcc: value for source control register * @didstc: value for destination control register * @dcon: base value for dcon register */ struct s3c24xx_txd { struct virt_dma_desc vd; struct list_head dsg_list; struct list_head *at; u8 width; u32 disrcc; u32 didstc; u32 dcon; }; struct s3c24xx_dma_chan; /* * struct s3c24xx_dma_phy - holder for the physical channels * @id: physical index to this channel * @valid: does the channel have all required elements * @base: virtual memory base (remapped) for the this channel * @irq: interrupt for this channel * @clk: clock for this channel * @lock: a lock to use when altering an instance of this struct * @serving: virtual channel currently being served by this physicalchannel * @host: a pointer to the host (internal use) */ struct s3c24xx_dma_phy { unsigned int id; bool valid; void __iomem *base; int irq; struct clk *clk; spinlock_t lock; struct s3c24xx_dma_chan *serving; struct s3c24xx_dma_engine *host; }; /* * struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel * @id: the id of the channel * @name: name of the channel * @vc: wrappped virtual channel * @phy: the physical channel utilized by this channel, if there is one * @runtime_addr: address for RX/TX according to the runtime config * @at: active transaction on this channel * @lock: a lock for this channel data * @host: a pointer to the host (internal use) * @state: whether the channel is idle, running etc * @slave: whether this channel is a device (slave) or for memcpy */ struct s3c24xx_dma_chan { int id; const char *name; struct virt_dma_chan vc; struct s3c24xx_dma_phy *phy; struct dma_slave_config cfg; struct s3c24xx_txd *at; struct s3c24xx_dma_engine *host; enum s3c24xx_dma_chan_state state; bool slave; }; /* * struct s3c24xx_dma_engine - the local state holder for the S3C24XX * @pdev: the corresponding platform device * @pdata: platform data passed in from the platform/machine * @base: virtual memory base (remapped) * @slave: slave engine for this instance * @memcpy: memcpy engine for this instance * @phy_chans: array of data for the physical channels */ struct s3c24xx_dma_engine { struct platform_device *pdev; const struct s3c24xx_dma_platdata *pdata; struct soc_data *sdata; void __iomem *base; struct dma_device slave; struct dma_device memcpy; struct s3c24xx_dma_phy *phy_chans; }; /* * Physical channel handling */ /* * Check whether a certain channel is busy or not. */ static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy) { unsigned int val = readl(phy->base + S3C24XX_DSTAT); return val & S3C24XX_DSTAT_STAT_BUSY; } static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan, struct s3c24xx_dma_phy *phy) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; int phyvalid; /* every phy is valid for memcopy channels */ if (!s3cchan->slave) return true; /* On newer variants all phys can be used for all virtual channels */ if (s3cdma->sdata->has_reqsel) return true; phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH)); return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false; } /* * Allocate a physical channel for a virtual channel * * Try to locate a physical channel to be used for this transfer. If all * are taken return NULL and the requester will have to cope by using * some fallback PIO mode or retrying later. */ static struct s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; struct s3c24xx_dma_channel *cdata; struct s3c24xx_dma_phy *phy = NULL; unsigned long flags; int i; int ret; if (s3cchan->slave) cdata = &pdata->channels[s3cchan->id]; for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) { phy = &s3cdma->phy_chans[i]; if (!phy->valid) continue; if (!s3c24xx_dma_phy_valid(s3cchan, phy)) continue; spin_lock_irqsave(&phy->lock, flags); if (!phy->serving) { phy->serving = s3cchan; spin_unlock_irqrestore(&phy->lock, flags); break; } spin_unlock_irqrestore(&phy->lock, flags); } /* No physical channel available, cope with it */ if (i == s3cdma->pdata->num_phy_channels) { dev_warn(&s3cdma->pdev->dev, "no phy channel available\n"); return NULL; } /* start the phy clock */ if (s3cdma->sdata->has_clocks) { ret = clk_enable(phy->clk); if (ret) { dev_err(&s3cdma->pdev->dev, "could not enable clock for channel %d, err %d\n", phy->id, ret); phy->serving = NULL; return NULL; } } return phy; } /* * Mark the physical channel as free. * * This drops the link between the physical and virtual channel. */ static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy) { struct s3c24xx_dma_engine *s3cdma = phy->host; if (s3cdma->sdata->has_clocks) clk_disable(phy->clk); phy->serving = NULL; } /* * Stops the channel by writing the stop bit. * This should not be used for an on-going transfer, but as a method of * shutting down a channel (eg, when it's no longer used) or terminating a * transfer. */ static void s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy) { writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG); } /* * Virtual channel handling */ static inline struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan) { return container_of(chan, struct s3c24xx_dma_chan, vc.chan); } static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_phy *phy = s3cchan->phy; struct s3c24xx_txd *txd = s3cchan->at; u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK; return tc * txd->width; } static int s3c24xx_dma_set_runtime_config(struct s3c24xx_dma_chan *s3cchan, struct dma_slave_config *config) { if (!s3cchan->slave) return -EINVAL; /* Reject definitely invalid configurations */ if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) return -EINVAL; s3cchan->cfg = *config; return 0; } /* * Transfer handling */ static inline struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx) { return container_of(tx, struct s3c24xx_txd, vd.tx); } static struct s3c24xx_txd *s3c24xx_dma_get_txd(void) { struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT); if (txd) { INIT_LIST_HEAD(&txd->dsg_list); txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD; } return txd; } static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd) { struct s3c24xx_sg *dsg, *_dsg; list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) { list_del(&dsg->node); kfree(dsg); } kfree(txd); } static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan, struct s3c24xx_txd *txd) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; struct s3c24xx_dma_phy *phy = s3cchan->phy; const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node); u32 dcon = txd->dcon; u32 val; /* transfer-size and -count from len and width */ switch (txd->width) { case 1: dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len; break; case 2: dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2); break; case 4: dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4); break; } if (s3cchan->slave) { struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; if (s3cdma->sdata->has_reqsel) { writel_relaxed((cdata->chansel << 1) | S3C24XX_DMAREQSEL_HW, phy->base + S3C24XX_DMAREQSEL); } else { int csel = cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH); csel &= S3C24XX_CHANSEL_REQ_MASK; dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT; dcon |= S3C24XX_DCON_HWTRIG; } } else { if (s3cdma->sdata->has_reqsel) writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL); } writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC); writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC); writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST); writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC); writel_relaxed(dcon, phy->base + S3C24XX_DCON); val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG); val &= ~S3C24XX_DMASKTRIG_STOP; val |= S3C24XX_DMASKTRIG_ON; /* trigger the dma operation for memcpy transfers */ if (!s3cchan->slave) val |= S3C24XX_DMASKTRIG_SWTRIG; writel(val, phy->base + S3C24XX_DMASKTRIG); } /* * Set the initial DMA register values and start first sg. */ static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_phy *phy = s3cchan->phy; struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc); struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); list_del(&txd->vd.node); s3cchan->at = txd; /* Wait for channel inactive */ while (s3c24xx_dma_phy_busy(phy)) cpu_relax(); /* point to the first element of the sg list */ txd->at = txd->dsg_list.next; s3c24xx_dma_start_next_sg(s3cchan, txd); } static void s3c24xx_dma_free_txd_list(struct s3c24xx_dma_engine *s3cdma, struct s3c24xx_dma_chan *s3cchan) { LIST_HEAD(head); vchan_get_all_descriptors(&s3cchan->vc, &head); vchan_dma_desc_free_list(&s3cchan->vc, &head); } /* * Try to allocate a physical channel. When successful, assign it to * this virtual channel, and initiate the next descriptor. The * virtual channel lock must be held at this point. */ static void s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; struct s3c24xx_dma_phy *phy; phy = s3c24xx_dma_get_phy(s3cchan); if (!phy) { dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer on %s\n", s3cchan->name); s3cchan->state = S3C24XX_DMA_CHAN_WAITING; return; } dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on %s\n", phy->id, s3cchan->name); s3cchan->phy = phy; s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; s3c24xx_dma_start_next_txd(s3cchan); } static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy, struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer on %s\n", phy->id, s3cchan->name); /* * We do this without taking the lock; we're really only concerned * about whether this pointer is NULL or not, and we're guaranteed * that this will only be called when it _already_ is non-NULL. */ phy->serving = s3cchan; s3cchan->phy = phy; s3cchan->state = S3C24XX_DMA_CHAN_RUNNING; s3c24xx_dma_start_next_txd(s3cchan); } /* * Free a physical DMA channel, potentially reallocating it to another * virtual channel if we have any pending. */ static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan) { struct s3c24xx_dma_engine *s3cdma = s3cchan->host; struct s3c24xx_dma_chan *p, *next; retry: next = NULL; /* Find a waiting virtual channel for the next transfer. */ list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node) if (p->state == S3C24XX_DMA_CHAN_WAITING) { next = p; break; } if (!next) { list_for_each_entry(p, &s3cdma->slave.channels, vc.chan.device_node) if (p->state == S3C24XX_DMA_CHAN_WAITING && s3c24xx_dma_phy_valid(p, s3cchan->phy)) { next = p; break; } } /* Ensure that the physical channel is stopped */ s3c24xx_dma_terminate_phy(s3cchan->phy); if (next) { bool success; /* * Eww. We know this isn't going to deadlock * but lockdep probably doesn't. */ spin_lock(&next->vc.lock); /* Re-check the state now that we have the lock */ success = next->state == S3C24XX_DMA_CHAN_WAITING; if (success) s3c24xx_dma_phy_reassign_start(s3cchan->phy, next); spin_unlock(&next->vc.lock); /* If the state changed, try to find another channel */ if (!success) goto retry; } else { /* No more jobs, so free up the physical channel */ s3c24xx_dma_put_phy(s3cchan->phy); } s3cchan->phy = NULL; s3cchan->state = S3C24XX_DMA_CHAN_IDLE; } static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd) { struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx); struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd->tx.chan); if (!s3cchan->slave) dma_descriptor_unmap(&vd->tx); s3c24xx_dma_free_txd(txd); } static irqreturn_t s3c24xx_dma_irq(int irq, void *data) { struct s3c24xx_dma_phy *phy = data; struct s3c24xx_dma_chan *s3cchan = phy->serving; struct s3c24xx_txd *txd; dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy->id); /* * Interrupts happen to notify the completion of a transfer and the * channel should have moved into its stop state already on its own. * Therefore interrupts on channels not bound to a virtual channel * should never happen. Nevertheless send a terminate command to the * channel if the unlikely case happens. */ if (unlikely(!s3cchan)) { dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n", phy->id); s3c24xx_dma_terminate_phy(phy); return IRQ_HANDLED; } spin_lock(&s3cchan->vc.lock); txd = s3cchan->at; if (txd) { /* when more sg's are in this txd, start the next one */ if (!list_is_last(txd->at, &txd->dsg_list)) { txd->at = txd->at->next; s3c24xx_dma_start_next_sg(s3cchan, txd); } else { s3cchan->at = NULL; vchan_cookie_complete(&txd->vd); /* * And start the next descriptor (if any), * otherwise free this channel. */ if (vchan_next_desc(&s3cchan->vc)) s3c24xx_dma_start_next_txd(s3cchan); else s3c24xx_dma_phy_free(s3cchan); } } spin_unlock(&s3cchan->vc.lock); return IRQ_HANDLED; } /* * The DMA ENGINE API */ static int s3c24xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg) { struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); struct s3c24xx_dma_engine *s3cdma = s3cchan->host; unsigned long flags; int ret = 0; spin_lock_irqsave(&s3cchan->vc.lock, flags); switch (cmd) { case DMA_SLAVE_CONFIG: ret = s3c24xx_dma_set_runtime_config(s3cchan, (struct dma_slave_config *)arg); break; case DMA_TERMINATE_ALL: if (!s3cchan->phy && !s3cchan->at) { dev_err(&s3cdma->pdev->dev, "trying to terminate already stopped channel %d\n", s3cchan->id); ret = -EINVAL; break; } s3cchan->state = S3C24XX_DMA_CHAN_IDLE; /* Mark physical channel as free */ if (s3cchan->phy) s3c24xx_dma_phy_free(s3cchan); /* Dequeue current job */ if (s3cchan->at) { s3c24xx_dma_desc_free(&s3cchan->at->vd); s3cchan->at = NULL; } /* Dequeue jobs not yet fired as well */ s3c24xx_dma_free_txd_list(s3cdma, s3cchan); break; default: /* Unknown command */ ret = -ENXIO; break; } spin_unlock_irqrestore(&s3cchan->vc.lock, flags); return ret; } static int s3c24xx_dma_alloc_chan_resources(struct dma_chan *chan) { return 0; } static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan) { /* Ensure all queued descriptors are freed */ vchan_free_chan_resources(to_virt_chan(chan)); } static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); struct s3c24xx_txd *txd; struct s3c24xx_sg *dsg; struct virt_dma_desc *vd; unsigned long flags; enum dma_status ret; size_t bytes = 0; spin_lock_irqsave(&s3cchan->vc.lock, flags); ret = dma_cookie_status(chan, cookie, txstate); if (ret == DMA_COMPLETE) { spin_unlock_irqrestore(&s3cchan->vc.lock, flags); return ret; } /* * There's no point calculating the residue if there's * no txstate to store the value. */ if (!txstate) { spin_unlock_irqrestore(&s3cchan->vc.lock, flags); return ret; } vd = vchan_find_desc(&s3cchan->vc, cookie); if (vd) { /* On the issued list, so hasn't been processed yet */ txd = to_s3c24xx_txd(&vd->tx); list_for_each_entry(dsg, &txd->dsg_list, node) bytes += dsg->len; } else { /* * Currently running, so sum over the pending sg's and * the currently active one. */ txd = s3cchan->at; dsg = list_entry(txd->at, struct s3c24xx_sg, node); list_for_each_entry_from(dsg, &txd->dsg_list, node) bytes += dsg->len; bytes += s3c24xx_dma_getbytes_chan(s3cchan); } spin_unlock_irqrestore(&s3cchan->vc.lock, flags); /* * This cookie not complete yet * Get number of bytes left in the active transactions and queue */ dma_set_residue(txstate, bytes); /* Whether waiting or running, we're in progress */ return ret; } /* * Initialize a descriptor to be used by memcpy submit */ static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy( struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags) { struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); struct s3c24xx_dma_engine *s3cdma = s3cchan->host; struct s3c24xx_txd *txd; struct s3c24xx_sg *dsg; int src_mod, dest_mod; dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n", len, s3cchan->name); if ((len & S3C24XX_DCON_TC_MASK) != len) { dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len); return NULL; } txd = s3c24xx_dma_get_txd(); if (!txd) return NULL; dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT); if (!dsg) { s3c24xx_dma_free_txd(txd); return NULL; } list_add_tail(&dsg->node, &txd->dsg_list); dsg->src_addr = src; dsg->dst_addr = dest; dsg->len = len; /* * Determine a suitable transfer width. * The DMA controller cannot fetch/store information which is not * naturally aligned on the bus, i.e., a 4 byte fetch must start at * an address divisible by 4 - more generally addr % width must be 0. */ src_mod = src % 4; dest_mod = dest % 4; switch (len % 4) { case 0: txd->width = (src_mod == 0 && dest_mod == 0) ? 4 : 1; break; case 2: txd->width = ((src_mod == 2 || src_mod == 0) && (dest_mod == 2 || dest_mod == 0)) ? 2 : 1; break; default: txd->width = 1; break; } txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT; txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT; txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK | S3C24XX_DCON_SERV_WHOLE; return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); } static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, unsigned long flags, void *context) { struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); struct s3c24xx_dma_engine *s3cdma = s3cchan->host; const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata; struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id]; struct s3c24xx_txd *txd; struct s3c24xx_sg *dsg; struct scatterlist *sg; dma_addr_t slave_addr; u32 hwcfg = 0; int tmp; dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from %s\n", sg_dma_len(sgl), s3cchan->name); txd = s3c24xx_dma_get_txd(); if (!txd) return NULL; if (cdata->handshake) txd->dcon |= S3C24XX_DCON_HANDSHAKE; switch (cdata->bus) { case S3C24XX_DMA_APB: txd->dcon |= S3C24XX_DCON_SYNC_PCLK; hwcfg |= S3C24XX_DISRCC_LOC_APB; break; case S3C24XX_DMA_AHB: txd->dcon |= S3C24XX_DCON_SYNC_HCLK; hwcfg |= S3C24XX_DISRCC_LOC_AHB; break; } /* * Always assume our peripheral desintation is a fixed * address in memory. */ hwcfg |= S3C24XX_DISRCC_INC_FIXED; /* * Individual dma operations are requested by the slave, * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE). */ txd->dcon |= S3C24XX_DCON_SERV_SINGLE; if (direction == DMA_MEM_TO_DEV) { txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT; txd->didstc = hwcfg; slave_addr = s3cchan->cfg.dst_addr; txd->width = s3cchan->cfg.dst_addr_width; } else if (direction == DMA_DEV_TO_MEM) { txd->disrcc = hwcfg; txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT; slave_addr = s3cchan->cfg.src_addr; txd->width = s3cchan->cfg.src_addr_width; } else { s3c24xx_dma_free_txd(txd); dev_err(&s3cdma->pdev->dev, "direction %d unsupported\n", direction); return NULL; } for_each_sg(sgl, sg, sg_len, tmp) { dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT); if (!dsg) { s3c24xx_dma_free_txd(txd); return NULL; } list_add_tail(&dsg->node, &txd->dsg_list); dsg->len = sg_dma_len(sg); if (direction == DMA_MEM_TO_DEV) { dsg->src_addr = sg_dma_address(sg); dsg->dst_addr = slave_addr; } else { /* DMA_DEV_TO_MEM */ dsg->src_addr = slave_addr; dsg->dst_addr = sg_dma_address(sg); } } return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags); } /* * Slave transactions callback to the slave device to allow * synchronization of slave DMA signals with the DMAC enable */ static void s3c24xx_dma_issue_pending(struct dma_chan *chan) { struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan); unsigned long flags; spin_lock_irqsave(&s3cchan->vc.lock, flags); if (vchan_issue_pending(&s3cchan->vc)) { if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING) s3c24xx_dma_phy_alloc_and_start(s3cchan); } spin_unlock_irqrestore(&s3cchan->vc.lock, flags); } /* * Bringup and teardown */ /* * Initialise the DMAC memcpy/slave channels. * Make a local wrapper to hold required data */ static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine *s3cdma, struct dma_device *dmadev, unsigned int channels, bool slave) { struct s3c24xx_dma_chan *chan; int i; INIT_LIST_HEAD(&dmadev->channels); /* * Register as many many memcpy as we have physical channels, * we won't always be able to use all but the code will have * to cope with that situation. */ for (i = 0; i < channels; i++) { chan = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL); if (!chan) { dev_err(dmadev->dev, "%s no memory for channel\n", __func__); return -ENOMEM; } chan->id = i; chan->host = s3cdma; chan->state = S3C24XX_DMA_CHAN_IDLE; if (slave) { chan->slave = true; chan->name = kasprintf(GFP_KERNEL, "slave%d", i); if (!chan->name) return -ENOMEM; } else { chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i); if (!chan->name) return -ENOMEM; } dev_dbg(dmadev->dev, "initialize virtual channel \"%s\"\n", chan->name); chan->vc.desc_free = s3c24xx_dma_desc_free; vchan_init(&chan->vc, dmadev); } dev_info(dmadev->dev, "initialized %d virtual %s channels\n", i, slave ? "slave" : "memcpy"); return i; } static void s3c24xx_dma_free_virtual_channels(struct dma_device *dmadev) { struct s3c24xx_dma_chan *chan = NULL; struct s3c24xx_dma_chan *next; list_for_each_entry_safe(chan, next, &dmadev->channels, vc.chan.device_node) list_del(&chan->vc.chan.device_node); } /* s3c2410, s3c2440 and s3c2442 have a 0x40 stride without separate clocks */ static struct soc_data soc_s3c2410 = { .stride = 0x40, .has_reqsel = false, .has_clocks = false, }; /* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */ static struct soc_data soc_s3c2412 = { .stride = 0x40, .has_reqsel = true, .has_clocks = true, }; /* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */ static struct soc_data soc_s3c2443 = { .stride = 0x100, .has_reqsel = true, .has_clocks = true, }; static struct platform_device_id s3c24xx_dma_driver_ids[] = { { .name = "s3c2410-dma", .driver_data = (kernel_ulong_t)&soc_s3c2410, }, { .name = "s3c2412-dma", .driver_data = (kernel_ulong_t)&soc_s3c2412, }, { .name = "s3c2443-dma", .driver_data = (kernel_ulong_t)&soc_s3c2443, }, { }, }; static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device *pdev) { return (struct soc_data *) platform_get_device_id(pdev)->driver_data; } static int s3c24xx_dma_probe(struct platform_device *pdev) { const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev); struct s3c24xx_dma_engine *s3cdma; struct soc_data *sdata; struct resource *res; int ret; int i; if (!pdata) { dev_err(&pdev->dev, "platform data missing\n"); return -ENODEV; } /* Basic sanity check */ if (pdata->num_phy_channels > MAX_DMA_CHANNELS) { dev_err(&pdev->dev, "to many dma channels %d, max %d\n", pdata->num_phy_channels, MAX_DMA_CHANNELS); return -EINVAL; } sdata = s3c24xx_dma_get_soc_data(pdev); if (!sdata) return -EINVAL; s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL); if (!s3cdma) return -ENOMEM; s3cdma->pdev = pdev; s3cdma->pdata = pdata; s3cdma->sdata = sdata; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); s3cdma->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(s3cdma->base)) return PTR_ERR(s3cdma->base); s3cdma->phy_chans = devm_kzalloc(&pdev->dev, sizeof(struct s3c24xx_dma_phy) * pdata->num_phy_channels, GFP_KERNEL); if (!s3cdma->phy_chans) return -ENOMEM; /* aquire irqs and clocks for all physical channels */ for (i = 0; i < pdata->num_phy_channels; i++) { struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i]; char clk_name[6]; phy->id = i; phy->base = s3cdma->base + (i * sdata->stride); phy->host = s3cdma; phy->irq = platform_get_irq(pdev, i); if (phy->irq < 0) { dev_err(&pdev->dev, "failed to get irq %d, err %d\n", i, phy->irq); continue; } ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq, 0, pdev->name, phy); if (ret) { dev_err(&pdev->dev, "Unable to request irq for channel %d, error %d\n", i, ret); continue; } if (sdata->has_clocks) { sprintf(clk_name, "dma.%d", i); phy->clk = devm_clk_get(&pdev->dev, clk_name); if (IS_ERR(phy->clk) && sdata->has_clocks) { dev_err(&pdev->dev, "unable to aquire clock for channel %d, error %lu", i, PTR_ERR(phy->clk)); continue; } ret = clk_prepare(phy->clk); if (ret) { dev_err(&pdev->dev, "clock for phy %d failed, error %d\n", i, ret); continue; } } spin_lock_init(&phy->lock); phy->valid = true; dev_dbg(&pdev->dev, "physical channel %d is %s\n", i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE"); } /* Initialize memcpy engine */ dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask); dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask); s3cdma->memcpy.dev = &pdev->dev; s3cdma->memcpy.device_alloc_chan_resources = s3c24xx_dma_alloc_chan_resources; s3cdma->memcpy.device_free_chan_resources = s3c24xx_dma_free_chan_resources; s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy; s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status; s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending; s3cdma->memcpy.device_control = s3c24xx_dma_control; /* Initialize slave engine for SoC internal dedicated peripherals */ dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask); dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask); s3cdma->slave.dev = &pdev->dev; s3cdma->slave.device_alloc_chan_resources = s3c24xx_dma_alloc_chan_resources; s3cdma->slave.device_free_chan_resources = s3c24xx_dma_free_chan_resources; s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status; s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending; s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg; s3cdma->slave.device_control = s3c24xx_dma_control; /* Register as many memcpy channels as there are physical channels */ ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy, pdata->num_phy_channels, false); if (ret <= 0) { dev_warn(&pdev->dev, "%s failed to enumerate memcpy channels - %d\n", __func__, ret); goto err_memcpy; } /* Register slave channels */ ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave, pdata->num_channels, true); if (ret <= 0) { dev_warn(&pdev->dev, "%s failed to enumerate slave channels - %d\n", __func__, ret); goto err_slave; } ret = dma_async_device_register(&s3cdma->memcpy); if (ret) { dev_warn(&pdev->dev, "%s failed to register memcpy as an async device - %d\n", __func__, ret); goto err_memcpy_reg; } ret = dma_async_device_register(&s3cdma->slave); if (ret) { dev_warn(&pdev->dev, "%s failed to register slave as an async device - %d\n", __func__, ret); goto err_slave_reg; } platform_set_drvdata(pdev, s3cdma); dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n", pdata->num_phy_channels); return 0; err_slave_reg: dma_async_device_unregister(&s3cdma->memcpy); err_memcpy_reg: s3c24xx_dma_free_virtual_channels(&s3cdma->slave); err_slave: s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy); err_memcpy: if (sdata->has_clocks) for (i = 0; i < pdata->num_phy_channels; i++) { struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i]; if (phy->valid) clk_unprepare(phy->clk); } return ret; } static int s3c24xx_dma_remove(struct platform_device *pdev) { const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev); struct s3c24xx_dma_engine *s3cdma = platform_get_drvdata(pdev); struct soc_data *sdata = s3c24xx_dma_get_soc_data(pdev); int i; dma_async_device_unregister(&s3cdma->slave); dma_async_device_unregister(&s3cdma->memcpy); s3c24xx_dma_free_virtual_channels(&s3cdma->slave); s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy); if (sdata->has_clocks) for (i = 0; i < pdata->num_phy_channels; i++) { struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i]; if (phy->valid) clk_unprepare(phy->clk); } return 0; } static struct platform_driver s3c24xx_dma_driver = { .driver = { .name = "s3c24xx-dma", .owner = THIS_MODULE, }, .id_table = s3c24xx_dma_driver_ids, .probe = s3c24xx_dma_probe, .remove = s3c24xx_dma_remove, }; module_platform_driver(s3c24xx_dma_driver); bool s3c24xx_dma_filter(struct dma_chan *chan, void *param) { struct s3c24xx_dma_chan *s3cchan; if (chan->device->dev->driver != &s3c24xx_dma_driver.driver) return false; s3cchan = to_s3c24xx_dma_chan(chan); return s3cchan->id == (int)param; } EXPORT_SYMBOL(s3c24xx_dma_filter); MODULE_DESCRIPTION("S3C24XX DMA Driver"); MODULE_AUTHOR("Heiko Stuebner"); MODULE_LICENSE("GPL v2");