diff options
Diffstat (limited to 'drivers/dma/edma.c')
| -rw-r--r-- | drivers/dma/edma.c | 1152 |
1 files changed, 1152 insertions, 0 deletions
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c new file mode 100644 index 00000000000..d08c4dedef3 --- /dev/null +++ b/drivers/dma/edma.c @@ -0,0 +1,1152 @@ +/* + * TI EDMA DMA engine driver + * + * Copyright 2012 Texas Instruments + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include <linux/platform_data/edma.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +/* + * This will go away when the private EDMA API is folded + * into this driver and the platform device(s) are + * instantiated in the arch code. We can only get away + * with this simplification because DA8XX may not be built + * in the same kernel image with other DaVinci parts. This + * avoids having to sprinkle dmaengine driver platform devices + * and data throughout all the existing board files. + */ +#ifdef CONFIG_ARCH_DAVINCI_DA8XX +#define EDMA_CTLRS 2 +#define EDMA_CHANS 32 +#else +#define EDMA_CTLRS 1 +#define EDMA_CHANS 64 +#endif /* CONFIG_ARCH_DAVINCI_DA8XX */ + +/* + * Max of 20 segments per channel to conserve PaRAM slots + * Also note that MAX_NR_SG should be atleast the no.of periods + * that are required for ASoC, otherwise DMA prep calls will + * fail. Today davinci-pcm is the only user of this driver and + * requires atleast 17 slots, so we setup the default to 20. + */ +#define MAX_NR_SG 20 +#define EDMA_MAX_SLOTS MAX_NR_SG +#define EDMA_DESCRIPTORS 16 + +struct edma_pset { + u32 len; + dma_addr_t addr; + struct edmacc_param param; +}; + +struct edma_desc { + struct virt_dma_desc vdesc; + struct list_head node; + enum dma_transfer_direction direction; + int cyclic; + int absync; + int pset_nr; + struct edma_chan *echan; + int processed; + + /* + * The following 4 elements are used for residue accounting. + * + * - processed_stat: the number of SG elements we have traversed + * so far to cover accounting. This is updated directly to processed + * during edma_callback and is always <= processed, because processed + * refers to the number of pending transfer (programmed to EDMA + * controller), where as processed_stat tracks number of transfers + * accounted for so far. + * + * - residue: The amount of bytes we have left to transfer for this desc + * + * - residue_stat: The residue in bytes of data we have covered + * so far for accounting. This is updated directly to residue + * during callbacks to keep it current. + * + * - sg_len: Tracks the length of the current intermediate transfer, + * this is required to update the residue during intermediate transfer + * completion callback. + */ + int processed_stat; + u32 sg_len; + u32 residue; + u32 residue_stat; + + struct edma_pset pset[0]; +}; + +struct edma_cc; + +struct edma_chan { + struct virt_dma_chan vchan; + struct list_head node; + struct edma_desc *edesc; + struct edma_cc *ecc; + int ch_num; + bool alloced; + int slot[EDMA_MAX_SLOTS]; + int missed; + struct dma_slave_config cfg; +}; + +struct edma_cc { + int ctlr; + struct dma_device dma_slave; + struct edma_chan slave_chans[EDMA_CHANS]; + int num_slave_chans; + int dummy_slot; +}; + +static inline struct edma_cc *to_edma_cc(struct dma_device *d) +{ + return container_of(d, struct edma_cc, dma_slave); +} + +static inline struct edma_chan *to_edma_chan(struct dma_chan *c) +{ + return container_of(c, struct edma_chan, vchan.chan); +} + +static inline struct edma_desc +*to_edma_desc(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct edma_desc, vdesc.tx); +} + +static void edma_desc_free(struct virt_dma_desc *vdesc) +{ + kfree(container_of(vdesc, struct edma_desc, vdesc)); +} + +/* Dispatch a queued descriptor to the controller (caller holds lock) */ +static void edma_execute(struct edma_chan *echan) +{ + struct virt_dma_desc *vdesc; + struct edma_desc *edesc; + struct device *dev = echan->vchan.chan.device->dev; + int i, j, left, nslots; + + /* If either we processed all psets or we're still not started */ + if (!echan->edesc || + echan->edesc->pset_nr == echan->edesc->processed) { + /* Get next vdesc */ + vdesc = vchan_next_desc(&echan->vchan); + if (!vdesc) { + echan->edesc = NULL; + return; + } + list_del(&vdesc->node); + echan->edesc = to_edma_desc(&vdesc->tx); + } + + edesc = echan->edesc; + + /* Find out how many left */ + left = edesc->pset_nr - edesc->processed; + nslots = min(MAX_NR_SG, left); + edesc->sg_len = 0; + + /* Write descriptor PaRAM set(s) */ + for (i = 0; i < nslots; i++) { + j = i + edesc->processed; + edma_write_slot(echan->slot[i], &edesc->pset[j].param); + edesc->sg_len += edesc->pset[j].len; + dev_vdbg(echan->vchan.chan.device->dev, + "\n pset[%d]:\n" + " chnum\t%d\n" + " slot\t%d\n" + " opt\t%08x\n" + " src\t%08x\n" + " dst\t%08x\n" + " abcnt\t%08x\n" + " ccnt\t%08x\n" + " bidx\t%08x\n" + " cidx\t%08x\n" + " lkrld\t%08x\n", + j, echan->ch_num, echan->slot[i], + edesc->pset[j].param.opt, + edesc->pset[j].param.src, + edesc->pset[j].param.dst, + edesc->pset[j].param.a_b_cnt, + edesc->pset[j].param.ccnt, + edesc->pset[j].param.src_dst_bidx, + edesc->pset[j].param.src_dst_cidx, + edesc->pset[j].param.link_bcntrld); + /* Link to the previous slot if not the last set */ + if (i != (nslots - 1)) + edma_link(echan->slot[i], echan->slot[i+1]); + } + + edesc->processed += nslots; + + /* + * If this is either the last set in a set of SG-list transactions + * then setup a link to the dummy slot, this results in all future + * events being absorbed and that's OK because we're done + */ + if (edesc->processed == edesc->pset_nr) { + if (edesc->cyclic) + edma_link(echan->slot[nslots-1], echan->slot[1]); + else + edma_link(echan->slot[nslots-1], + echan->ecc->dummy_slot); + } + + if (edesc->processed <= MAX_NR_SG) { + dev_dbg(dev, "first transfer starting on channel %d\n", + echan->ch_num); + edma_start(echan->ch_num); + } else { + dev_dbg(dev, "chan: %d: completed %d elements, resuming\n", + echan->ch_num, edesc->processed); + edma_resume(echan->ch_num); + } + + /* + * This happens due to setup times between intermediate transfers + * in long SG lists which have to be broken up into transfers of + * MAX_NR_SG + */ + if (echan->missed) { + dev_dbg(dev, "missed event on channel %d\n", echan->ch_num); + edma_clean_channel(echan->ch_num); + edma_stop(echan->ch_num); + edma_start(echan->ch_num); + edma_trigger_channel(echan->ch_num); + echan->missed = 0; + } +} + +static int edma_terminate_all(struct edma_chan *echan) +{ + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&echan->vchan.lock, flags); + + /* + * Stop DMA activity: we assume the callback will not be called + * after edma_dma() returns (even if it does, it will see + * echan->edesc is NULL and exit.) + */ + if (echan->edesc) { + echan->edesc = NULL; + edma_stop(echan->ch_num); + } + + vchan_get_all_descriptors(&echan->vchan, &head); + spin_unlock_irqrestore(&echan->vchan.lock, flags); + vchan_dma_desc_free_list(&echan->vchan, &head); + + return 0; +} + +static int edma_slave_config(struct edma_chan *echan, + struct dma_slave_config *cfg) +{ + if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || + cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) + return -EINVAL; + + memcpy(&echan->cfg, cfg, sizeof(echan->cfg)); + + return 0; +} + +static int edma_dma_pause(struct edma_chan *echan) +{ + /* Pause/Resume only allowed with cyclic mode */ + if (!echan->edesc->cyclic) + return -EINVAL; + + edma_pause(echan->ch_num); + return 0; +} + +static int edma_dma_resume(struct edma_chan *echan) +{ + /* Pause/Resume only allowed with cyclic mode */ + if (!echan->edesc->cyclic) + return -EINVAL; + + edma_resume(echan->ch_num); + return 0; +} + +static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, + unsigned long arg) +{ + int ret = 0; + struct dma_slave_config *config; + struct edma_chan *echan = to_edma_chan(chan); + + switch (cmd) { + case DMA_TERMINATE_ALL: + edma_terminate_all(echan); + break; + case DMA_SLAVE_CONFIG: + config = (struct dma_slave_config *)arg; + ret = edma_slave_config(echan, config); + break; + case DMA_PAUSE: + ret = edma_dma_pause(echan); + break; + + case DMA_RESUME: + ret = edma_dma_resume(echan); + break; + + default: + ret = -ENOSYS; + } + + return ret; +} + +/* + * A PaRAM set configuration abstraction used by other modes + * @chan: Channel who's PaRAM set we're configuring + * @pset: PaRAM set to initialize and setup. + * @src_addr: Source address of the DMA + * @dst_addr: Destination address of the DMA + * @burst: In units of dev_width, how much to send + * @dev_width: How much is the dev_width + * @dma_length: Total length of the DMA transfer + * @direction: Direction of the transfer + */ +static int edma_config_pset(struct dma_chan *chan, struct edma_pset *epset, + dma_addr_t src_addr, dma_addr_t dst_addr, u32 burst, + enum dma_slave_buswidth dev_width, unsigned int dma_length, + enum dma_transfer_direction direction) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + struct edmacc_param *param = &epset->param; + int acnt, bcnt, ccnt, cidx; + int src_bidx, dst_bidx, src_cidx, dst_cidx; + int absync; + + acnt = dev_width; + + /* src/dst_maxburst == 0 is the same case as src/dst_maxburst == 1 */ + if (!burst) + burst = 1; + /* + * If the maxburst is equal to the fifo width, use + * A-synced transfers. This allows for large contiguous + * buffer transfers using only one PaRAM set. + */ + if (burst == 1) { + /* + * For the A-sync case, bcnt and ccnt are the remainder + * and quotient respectively of the division of: + * (dma_length / acnt) by (SZ_64K -1). This is so + * that in case bcnt over flows, we have ccnt to use. + * Note: In A-sync tranfer only, bcntrld is used, but it + * only applies for sg_dma_len(sg) >= SZ_64K. + * In this case, the best way adopted is- bccnt for the + * first frame will be the remainder below. Then for + * every successive frame, bcnt will be SZ_64K-1. This + * is assured as bcntrld = 0xffff in end of function. + */ + absync = false; + ccnt = dma_length / acnt / (SZ_64K - 1); + bcnt = dma_length / acnt - ccnt * (SZ_64K - 1); + /* + * If bcnt is non-zero, we have a remainder and hence an + * extra frame to transfer, so increment ccnt. + */ + if (bcnt) + ccnt++; + else + bcnt = SZ_64K - 1; + cidx = acnt; + } else { + /* + * If maxburst is greater than the fifo address_width, + * use AB-synced transfers where A count is the fifo + * address_width and B count is the maxburst. In this + * case, we are limited to transfers of C count frames + * of (address_width * maxburst) where C count is limited + * to SZ_64K-1. This places an upper bound on the length + * of an SG segment that can be handled. + */ + absync = true; + bcnt = burst; + ccnt = dma_length / (acnt * bcnt); + if (ccnt > (SZ_64K - 1)) { + dev_err(dev, "Exceeded max SG segment size\n"); + return -EINVAL; + } + cidx = acnt * bcnt; + } + + epset->len = dma_length; + + if (direction == DMA_MEM_TO_DEV) { + src_bidx = acnt; + src_cidx = cidx; + dst_bidx = 0; + dst_cidx = 0; + epset->addr = src_addr; + } else if (direction == DMA_DEV_TO_MEM) { + src_bidx = 0; + src_cidx = 0; + dst_bidx = acnt; + dst_cidx = cidx; + epset->addr = dst_addr; + } else if (direction == DMA_MEM_TO_MEM) { + src_bidx = acnt; + src_cidx = cidx; + dst_bidx = acnt; + dst_cidx = cidx; + } else { + dev_err(dev, "%s: direction not implemented yet\n", __func__); + return -EINVAL; + } + + param->opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num)); + /* Configure A or AB synchronized transfers */ + if (absync) + param->opt |= SYNCDIM; + + param->src = src_addr; + param->dst = dst_addr; + + param->src_dst_bidx = (dst_bidx << 16) | src_bidx; + param->src_dst_cidx = (dst_cidx << 16) | src_cidx; + + param->a_b_cnt = bcnt << 16 | acnt; + param->ccnt = ccnt; + /* + * Only time when (bcntrld) auto reload is required is for + * A-sync case, and in this case, a requirement of reload value + * of SZ_64K-1 only is assured. 'link' is initially set to NULL + * and then later will be populated by edma_execute. + */ + param->link_bcntrld = 0xffffffff; + return absync; +} + +static struct dma_async_tx_descriptor *edma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long tx_flags, void *context) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + struct edma_desc *edesc; + dma_addr_t src_addr = 0, dst_addr = 0; + enum dma_slave_buswidth dev_width; + u32 burst; + struct scatterlist *sg; + int i, nslots, ret; + + if (unlikely(!echan || !sgl || !sg_len)) + return NULL; + + if (direction == DMA_DEV_TO_MEM) { + src_addr = echan->cfg.src_addr; + dev_width = echan->cfg.src_addr_width; + burst = echan->cfg.src_maxburst; + } else if (direction == DMA_MEM_TO_DEV) { + dst_addr = echan->cfg.dst_addr; + dev_width = echan->cfg.dst_addr_width; + burst = echan->cfg.dst_maxburst; + } else { + dev_err(dev, "%s: bad direction: %d\n", __func__, direction); + return NULL; + } + + if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) { + dev_err(dev, "%s: Undefined slave buswidth\n", __func__); + return NULL; + } + + edesc = kzalloc(sizeof(*edesc) + sg_len * + sizeof(edesc->pset[0]), GFP_ATOMIC); + if (!edesc) { + dev_err(dev, "%s: Failed to allocate a descriptor\n", __func__); + return NULL; + } + + edesc->pset_nr = sg_len; + edesc->residue = 0; + edesc->direction = direction; + edesc->echan = echan; + + /* Allocate a PaRAM slot, if needed */ + nslots = min_t(unsigned, MAX_NR_SG, sg_len); + + for (i = 0; i < nslots; i++) { + if (echan->slot[i] < 0) { + echan->slot[i] = + edma_alloc_slot(EDMA_CTLR(echan->ch_num), + EDMA_SLOT_ANY); + if (echan->slot[i] < 0) { + kfree(edesc); + dev_err(dev, "%s: Failed to allocate slot\n", + __func__); + return NULL; + } + } + } + + /* Configure PaRAM sets for each SG */ + for_each_sg(sgl, sg, sg_len, i) { + /* Get address for each SG */ + if (direction == DMA_DEV_TO_MEM) + dst_addr = sg_dma_address(sg); + else + src_addr = sg_dma_address(sg); + + ret = edma_config_pset(chan, &edesc->pset[i], src_addr, + dst_addr, burst, dev_width, + sg_dma_len(sg), direction); + if (ret < 0) { + kfree(edesc); + return NULL; + } + + edesc->absync = ret; + edesc->residue += sg_dma_len(sg); + + /* If this is the last in a current SG set of transactions, + enable interrupts so that next set is processed */ + if (!((i+1) % MAX_NR_SG)) + edesc->pset[i].param.opt |= TCINTEN; + + /* If this is the last set, enable completion interrupt flag */ + if (i == sg_len - 1) + edesc->pset[i].param.opt |= TCINTEN; + } + edesc->residue_stat = edesc->residue; + + return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); +} + +struct dma_async_tx_descriptor *edma_prep_dma_memcpy( + struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, + size_t len, unsigned long tx_flags) +{ + int ret; + struct edma_desc *edesc; + struct device *dev = chan->device->dev; + struct edma_chan *echan = to_edma_chan(chan); + + if (unlikely(!echan || !len)) + return NULL; + + edesc = kzalloc(sizeof(*edesc) + sizeof(edesc->pset[0]), GFP_ATOMIC); + if (!edesc) { + dev_dbg(dev, "Failed to allocate a descriptor\n"); + return NULL; + } + + edesc->pset_nr = 1; + + ret = edma_config_pset(chan, &edesc->pset[0], src, dest, 1, + DMA_SLAVE_BUSWIDTH_4_BYTES, len, DMA_MEM_TO_MEM); + if (ret < 0) + return NULL; + + edesc->absync = ret; + + /* + * Enable intermediate transfer chaining to re-trigger channel + * on completion of every TR, and enable transfer-completion + * interrupt on completion of the whole transfer. + */ + edesc->pset[0].param.opt |= ITCCHEN; + edesc->pset[0].param.opt |= TCINTEN; + + return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); +} + +static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long tx_flags, void *context) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + struct edma_desc *edesc; + dma_addr_t src_addr, dst_addr; + enum dma_slave_buswidth dev_width; + u32 burst; + int i, ret, nslots; + + if (unlikely(!echan || !buf_len || !period_len)) + return NULL; + + if (direction == DMA_DEV_TO_MEM) { + src_addr = echan->cfg.src_addr; + dst_addr = buf_addr; + dev_width = echan->cfg.src_addr_width; + burst = echan->cfg.src_maxburst; + } else if (direction == DMA_MEM_TO_DEV) { + src_addr = buf_addr; + dst_addr = echan->cfg.dst_addr; + dev_width = echan->cfg.dst_addr_width; + burst = echan->cfg.dst_maxburst; + } else { + dev_err(dev, "%s: bad direction: %d\n", __func__, direction); + return NULL; + } + + if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) { + dev_err(dev, "%s: Undefined slave buswidth\n", __func__); + return NULL; + } + + if (unlikely(buf_len % period_len)) { + dev_err(dev, "Period should be multiple of Buffer length\n"); + return NULL; + } + + nslots = (buf_len / period_len) + 1; + + /* + * Cyclic DMA users such as audio cannot tolerate delays introduced + * by cases where the number of periods is more than the maximum + * number of SGs the EDMA driver can handle at a time. For DMA types + * such as Slave SGs, such delays are tolerable and synchronized, + * but the synchronization is difficult to achieve with Cyclic and + * cannot be guaranteed, so we error out early. + */ + if (nslots > MAX_NR_SG) + return NULL; + + edesc = kzalloc(sizeof(*edesc) + nslots * + sizeof(edesc->pset[0]), GFP_ATOMIC); + if (!edesc) { + dev_err(dev, "%s: Failed to allocate a descriptor\n", __func__); + return NULL; + } + + edesc->cyclic = 1; + edesc->pset_nr = nslots; + edesc->residue = edesc->residue_stat = buf_len; + edesc->direction = direction; + edesc->echan = echan; + + dev_dbg(dev, "%s: channel=%d nslots=%d period_len=%zu buf_len=%zu\n", + __func__, echan->ch_num, nslots, period_len, buf_len); + + for (i = 0; i < nslots; i++) { + /* Allocate a PaRAM slot, if needed */ + if (echan->slot[i] < 0) { + echan->slot[i] = + edma_alloc_slot(EDMA_CTLR(echan->ch_num), + EDMA_SLOT_ANY); + if (echan->slot[i] < 0) { + kfree(edesc); + dev_err(dev, "%s: Failed to allocate slot\n", + __func__); + return NULL; + } + } + + if (i == nslots - 1) { + memcpy(&edesc->pset[i], &edesc->pset[0], + sizeof(edesc->pset[0])); + break; + } + + ret = edma_config_pset(chan, &edesc->pset[i], src_addr, + dst_addr, burst, dev_width, period_len, + direction); + if (ret < 0) { + kfree(edesc); + return NULL; + } + + if (direction == DMA_DEV_TO_MEM) + dst_addr += period_len; + else + src_addr += period_len; + + dev_vdbg(dev, "%s: Configure period %d of buf:\n", __func__, i); + dev_vdbg(dev, + "\n pset[%d]:\n" + " chnum\t%d\n" + " slot\t%d\n" + " opt\t%08x\n" + " src\t%08x\n" + " dst\t%08x\n" + " abcnt\t%08x\n" + " ccnt\t%08x\n" + " bidx\t%08x\n" + " cidx\t%08x\n" + " lkrld\t%08x\n", + i, echan->ch_num, echan->slot[i], + edesc->pset[i].param.opt, + edesc->pset[i].param.src, + edesc->pset[i].param.dst, + edesc->pset[i].param.a_b_cnt, + edesc->pset[i].param.ccnt, + edesc->pset[i].param.src_dst_bidx, + edesc->pset[i].param.src_dst_cidx, + edesc->pset[i].param.link_bcntrld); + + edesc->absync = ret; + + /* + * Enable interrupts for every period because callback + * has to be called for every period. + */ + edesc->pset[i].param.opt |= TCINTEN; + } + + return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); +} + +static void edma_callback(unsigned ch_num, u16 ch_status, void *data) +{ + struct edma_chan *echan = data; + struct device *dev = echan->vchan.chan.device->dev; + struct edma_desc *edesc; + struct edmacc_param p; + + edesc = echan->edesc; + + /* Pause the channel for non-cyclic */ + if (!edesc || (edesc && !edesc->cyclic)) + edma_pause(echan->ch_num); + + switch (ch_status) { + case EDMA_DMA_COMPLETE: + spin_lock(&echan->vchan.lock); + + if (edesc) { + if (edesc->cyclic) { + vchan_cyclic_callback(&edesc->vdesc); + } else if (edesc->processed == edesc->pset_nr) { + dev_dbg(dev, "Transfer complete, stopping channel %d\n", ch_num); + edesc->residue = 0; + edma_stop(echan->ch_num); + vchan_cookie_complete(&edesc->vdesc); + edma_execute(echan); + } else { + dev_dbg(dev, "Intermediate transfer complete on channel %d\n", ch_num); + + /* Update statistics for tx_status */ + edesc->residue -= edesc->sg_len; + edesc->residue_stat = edesc->residue; + edesc->processed_stat = edesc->processed; + + edma_execute(echan); + } + } + + spin_unlock(&echan->vchan.lock); + + break; + case EDMA_DMA_CC_ERROR: + spin_lock(&echan->vchan.lock); + + edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p); + + /* + * Issue later based on missed flag which will be sure + * to happen as: + * (1) we finished transmitting an intermediate slot and + * edma_execute is coming up. + * (2) or we finished current transfer and issue will + * call edma_execute. + * + * Important note: issuing can be dangerous here and + * lead to some nasty recursion when we are in a NULL + * slot. So we avoid doing so and set the missed flag. + */ + if (p.a_b_cnt == 0 && p.ccnt == 0) { + dev_dbg(dev, "Error occurred, looks like slot is null, just setting miss\n"); + echan->missed = 1; + } else { + /* + * The slot is already programmed but the event got + * missed, so its safe to issue it here. + */ + dev_dbg(dev, "Error occurred but slot is non-null, TRIGGERING\n"); + edma_clean_channel(echan->ch_num); + edma_stop(echan->ch_num); + edma_start(echan->ch_num); + edma_trigger_channel(echan->ch_num); + } + + spin_unlock(&echan->vchan.lock); + + break; + default: + break; + } +} + +/* Alloc channel resources */ +static int edma_alloc_chan_resources(struct dma_chan *chan) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + int ret; + int a_ch_num; + LIST_HEAD(descs); + + a_ch_num = edma_alloc_channel(echan->ch_num, edma_callback, + chan, EVENTQ_DEFAULT); + + if (a_ch_num < 0) { + ret = -ENODEV; + goto err_no_chan; + } + + if (a_ch_num != echan->ch_num) { + dev_err(dev, "failed to allocate requested channel %u:%u\n", + EDMA_CTLR(echan->ch_num), + EDMA_CHAN_SLOT(echan->ch_num)); + ret = -ENODEV; + goto err_wrong_chan; + } + + echan->alloced = true; + echan->slot[0] = echan->ch_num; + + dev_dbg(dev, "allocated channel %d for %u:%u\n", echan->ch_num, + EDMA_CTLR(echan->ch_num), EDMA_CHAN_SLOT(echan->ch_num)); + + return 0; + +err_wrong_chan: + edma_free_channel(a_ch_num); +err_no_chan: + return ret; +} + +/* Free channel resources */ +static void edma_free_chan_resources(struct dma_chan *chan) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + int i; + + /* Terminate transfers */ + edma_stop(echan->ch_num); + + vchan_free_chan_resources(&echan->vchan); + + /* Free EDMA PaRAM slots */ + for (i = 1; i < EDMA_MAX_SLOTS; i++) { + if (echan->slot[i] >= 0) { + edma_free_slot(echan->slot[i]); + echan->slot[i] = -1; + } + } + + /* Free EDMA channel */ + if (echan->alloced) { + edma_free_channel(echan->ch_num); + echan->alloced = false; + } + + dev_dbg(dev, "freeing channel for %u\n", echan->ch_num); +} + +/* Send pending descriptor to hardware */ +static void edma_issue_pending(struct dma_chan *chan) +{ + struct edma_chan *echan = to_edma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&echan->vchan.lock, flags); + if (vchan_issue_pending(&echan->vchan) && !echan->edesc) + edma_execute(echan); + spin_unlock_irqrestore(&echan->vchan.lock, flags); +} + +static u32 edma_residue(struct edma_desc *edesc) +{ + bool dst = edesc->direction == DMA_DEV_TO_MEM; + struct edma_pset *pset = edesc->pset; + dma_addr_t done, pos; + int i; + + /* + * We always read the dst/src position from the first RamPar + * pset. That's the one which is active now. + */ + pos = edma_get_position(edesc->echan->slot[0], dst); + + /* + * Cyclic is simple. Just subtract pset[0].addr from pos. + * + * We never update edesc->residue in the cyclic case, so we + * can tell the remaining room to the end of the circular + * buffer. + */ + if (edesc->cyclic) { + done = pos - pset->addr; + edesc->residue_stat = edesc->residue - done; + return edesc->residue_stat; + } + + /* + * For SG operation we catch up with the last processed + * status. + */ + pset += edesc->processed_stat; + + for (i = edesc->processed_stat; i < edesc->processed; i++, pset++) { + /* + * If we are inside this pset address range, we know + * this is the active one. Get the current delta and + * stop walking the psets. + */ + if (pos >= pset->addr && pos < pset->addr + pset->len) + return edesc->residue_stat - (pos - pset->addr); + + /* Otherwise mark it done and update residue_stat. */ + edesc->processed_stat++; + edesc->residue_stat -= pset->len; + } + return edesc->residue_stat; +} + +/* Check request completion status */ +static enum dma_status edma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct virt_dma_desc *vdesc; + enum dma_status ret; + unsigned long flags; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_COMPLETE || !txstate) + return ret; + + spin_lock_irqsave(&echan->vchan.lock, flags); + if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) + txstate->residue = edma_residue(echan->edesc); + else if ((vdesc = vchan_find_desc(&echan->vchan, cookie))) + txstate->residue = to_edma_desc(&vdesc->tx)->residue; + spin_unlock_irqrestore(&echan->vchan.lock, flags); + + return ret; +} + +static void __init edma_chan_init(struct edma_cc *ecc, + struct dma_device *dma, + struct edma_chan *echans) +{ + int i, j; + + for (i = 0; i < EDMA_CHANS; i++) { + struct edma_chan *echan = &echans[i]; + echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i); + echan->ecc = ecc; + echan->vchan.desc_free = edma_desc_free; + + vchan_init(&echan->vchan, dma); + + INIT_LIST_HEAD(&echan->node); + for (j = 0; j < EDMA_MAX_SLOTS; j++) + echan->slot[j] = -1; + } +} + +#define EDMA_DMA_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) + +static int edma_dma_device_slave_caps(struct dma_chan *dchan, + struct dma_slave_caps *caps) +{ + caps->src_addr_widths = EDMA_DMA_BUSWIDTHS; + caps->dstn_addr_widths = EDMA_DMA_BUSWIDTHS; + caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + caps->cmd_pause = true; + caps->cmd_terminate = true; + caps->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + + return 0; +} + +static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma, + struct device *dev) +{ + dma->device_prep_slave_sg = edma_prep_slave_sg; + dma->device_prep_dma_cyclic = edma_prep_dma_cyclic; + dma->device_prep_dma_memcpy = edma_prep_dma_memcpy; + dma->device_alloc_chan_resources = edma_alloc_chan_resources; + dma->device_free_chan_resources = edma_free_chan_resources; + dma->device_issue_pending = edma_issue_pending; + dma->device_tx_status = edma_tx_status; + dma->device_control = edma_control; + dma->device_slave_caps = edma_dma_device_slave_caps; + dma->dev = dev; + + /* + * code using dma memcpy must make sure alignment of + * length is at dma->copy_align boundary. + */ + dma->copy_align = DMA_SLAVE_BUSWIDTH_4_BYTES; + + INIT_LIST_HEAD(&dma->channels); +} + +static int edma_probe(struct platform_device *pdev) +{ + struct edma_cc *ecc; + int ret; + + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + if (ret) + return ret; + + ecc = devm_kzalloc(&pdev->dev, sizeof(*ecc), GFP_KERNEL); + if (!ecc) { + dev_err(&pdev->dev, "Can't allocate controller\n"); + return -ENOMEM; + } + + ecc->ctlr = pdev->id; + ecc->dummy_slot = edma_alloc_slot(ecc->ctlr, EDMA_SLOT_ANY); + if (ecc->dummy_slot < 0) { + dev_err(&pdev->dev, "Can't allocate PaRAM dummy slot\n"); + return -EIO; + } + + dma_cap_zero(ecc->dma_slave.cap_mask); + dma_cap_set(DMA_SLAVE, ecc->dma_slave.cap_mask); + dma_cap_set(DMA_CYCLIC, ecc->dma_slave.cap_mask); + dma_cap_set(DMA_MEMCPY, ecc->dma_slave.cap_mask); + + edma_dma_init(ecc, &ecc->dma_slave, &pdev->dev); + + edma_chan_init(ecc, &ecc->dma_slave, ecc->slave_chans); + + ret = dma_async_device_register(&ecc->dma_slave); + if (ret) + goto err_reg1; + + platform_set_drvdata(pdev, ecc); + + dev_info(&pdev->dev, "TI EDMA DMA engine driver\n"); + + return 0; + +err_reg1: + edma_free_slot(ecc->dummy_slot); + return ret; +} + +static int edma_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct edma_cc *ecc = dev_get_drvdata(dev); + + dma_async_device_unregister(&ecc->dma_slave); + edma_free_slot(ecc->dummy_slot); + + return 0; +} + +static struct platform_driver edma_driver = { + .probe = edma_probe, + .remove = edma_remove, + .driver = { + .name = "edma-dma-engine", + .owner = THIS_MODULE, + }, +}; + +bool edma_filter_fn(struct dma_chan *chan, void *param) +{ + if (chan->device->dev->driver == &edma_driver.driver) { + struct edma_chan *echan = to_edma_chan(chan); + unsigned ch_req = *(unsigned *)param; + return ch_req == echan->ch_num; + } + return false; +} +EXPORT_SYMBOL(edma_filter_fn); + +static struct platform_device *pdev0, *pdev1; + +static const struct platform_device_info edma_dev_info0 = { + .name = "edma-dma-engine", + .id = 0, + .dma_mask = DMA_BIT_MASK(32), +}; + +static const struct platform_device_info edma_dev_info1 = { + .name = "edma-dma-engine", + .id = 1, + .dma_mask = DMA_BIT_MASK(32), +}; + +static int edma_init(void) +{ + int ret = platform_driver_register(&edma_driver); + + if (ret == 0) { + pdev0 = platform_device_register_full(&edma_dev_info0); + if (IS_ERR(pdev0)) { + platform_driver_unregister(&edma_driver); + ret = PTR_ERR(pdev0); + goto out; + } + } + + if (EDMA_CTLRS == 2) { + pdev1 = platform_device_register_full(&edma_dev_info1); + if (IS_ERR(pdev1)) { + platform_driver_unregister(&edma_driver); + platform_device_unregister(pdev0); + ret = PTR_ERR(pdev1); + } + } + +out: + return ret; +} +subsys_initcall(edma_init); + +static void __exit edma_exit(void) +{ + platform_device_unregister(pdev0); + if (pdev1) + platform_device_unregister(pdev1); + platform_driver_unregister(&edma_driver); +} +module_exit(edma_exit); + +MODULE_AUTHOR("Matt Porter <matt.porter@linaro.org>"); +MODULE_DESCRIPTION("TI EDMA DMA engine driver"); +MODULE_LICENSE("GPL v2"); |