diff options
Diffstat (limited to 'drivers/dma/omap-dma.c')
| -rw-r--r-- | drivers/dma/omap-dma.c | 669 |
1 files changed, 669 insertions, 0 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c new file mode 100644 index 00000000000..ae056182613 --- /dev/null +++ b/drivers/dma/omap-dma.c @@ -0,0 +1,669 @@ +/* + * OMAP DMAengine support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#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/omap-dma.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "virt-dma.h" +#include <plat/dma.h> + +struct omap_dmadev { + struct dma_device ddev; + spinlock_t lock; + struct tasklet_struct task; + struct list_head pending; +}; + +struct omap_chan { + struct virt_dma_chan vc; + struct list_head node; + + struct dma_slave_config cfg; + unsigned dma_sig; + bool cyclic; + + int dma_ch; + struct omap_desc *desc; + unsigned sgidx; +}; + +struct omap_sg { + dma_addr_t addr; + uint32_t en; /* number of elements (24-bit) */ + uint32_t fn; /* number of frames (16-bit) */ +}; + +struct omap_desc { + struct virt_dma_desc vd; + enum dma_transfer_direction dir; + dma_addr_t dev_addr; + + int16_t fi; /* for OMAP_DMA_SYNC_PACKET */ + uint8_t es; /* OMAP_DMA_DATA_TYPE_xxx */ + uint8_t sync_mode; /* OMAP_DMA_SYNC_xxx */ + uint8_t sync_type; /* OMAP_DMA_xxx_SYNC* */ + uint8_t periph_port; /* Peripheral port */ + + unsigned sglen; + struct omap_sg sg[0]; +}; + +static const unsigned es_bytes[] = { + [OMAP_DMA_DATA_TYPE_S8] = 1, + [OMAP_DMA_DATA_TYPE_S16] = 2, + [OMAP_DMA_DATA_TYPE_S32] = 4, +}; + +static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d) +{ + return container_of(d, struct omap_dmadev, ddev); +} + +static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c) +{ + return container_of(c, struct omap_chan, vc.chan); +} + +static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t) +{ + return container_of(t, struct omap_desc, vd.tx); +} + +static void omap_dma_desc_free(struct virt_dma_desc *vd) +{ + kfree(container_of(vd, struct omap_desc, vd)); +} + +static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d, + unsigned idx) +{ + struct omap_sg *sg = d->sg + idx; + + if (d->dir == DMA_DEV_TO_MEM) + omap_set_dma_dest_params(c->dma_ch, OMAP_DMA_PORT_EMIFF, + OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0); + else + omap_set_dma_src_params(c->dma_ch, OMAP_DMA_PORT_EMIFF, + OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0); + + omap_set_dma_transfer_params(c->dma_ch, d->es, sg->en, sg->fn, + d->sync_mode, c->dma_sig, d->sync_type); + + omap_start_dma(c->dma_ch); +} + +static void omap_dma_start_desc(struct omap_chan *c) +{ + struct virt_dma_desc *vd = vchan_next_desc(&c->vc); + struct omap_desc *d; + + if (!vd) { + c->desc = NULL; + return; + } + + list_del(&vd->node); + + c->desc = d = to_omap_dma_desc(&vd->tx); + c->sgidx = 0; + + if (d->dir == DMA_DEV_TO_MEM) + omap_set_dma_src_params(c->dma_ch, d->periph_port, + OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi); + else + omap_set_dma_dest_params(c->dma_ch, d->periph_port, + OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi); + + omap_dma_start_sg(c, d, 0); +} + +static void omap_dma_callback(int ch, u16 status, void *data) +{ + struct omap_chan *c = data; + struct omap_desc *d; + unsigned long flags; + + spin_lock_irqsave(&c->vc.lock, flags); + d = c->desc; + if (d) { + if (!c->cyclic) { + if (++c->sgidx < d->sglen) { + omap_dma_start_sg(c, d, c->sgidx); + } else { + omap_dma_start_desc(c); + vchan_cookie_complete(&d->vd); + } + } else { + vchan_cyclic_callback(&d->vd); + } + } + spin_unlock_irqrestore(&c->vc.lock, flags); +} + +/* + * This callback schedules all pending channels. We could be more + * clever here by postponing allocation of the real DMA channels to + * this point, and freeing them when our virtual channel becomes idle. + * + * We would then need to deal with 'all channels in-use' + */ +static void omap_dma_sched(unsigned long data) +{ + struct omap_dmadev *d = (struct omap_dmadev *)data; + LIST_HEAD(head); + + spin_lock_irq(&d->lock); + list_splice_tail_init(&d->pending, &head); + spin_unlock_irq(&d->lock); + + while (!list_empty(&head)) { + struct omap_chan *c = list_first_entry(&head, + struct omap_chan, node); + + spin_lock_irq(&c->vc.lock); + list_del_init(&c->node); + omap_dma_start_desc(c); + spin_unlock_irq(&c->vc.lock); + } +} + +static int omap_dma_alloc_chan_resources(struct dma_chan *chan) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + + dev_info(c->vc.chan.device->dev, "allocating channel for %u\n", c->dma_sig); + + return omap_request_dma(c->dma_sig, "DMA engine", + omap_dma_callback, c, &c->dma_ch); +} + +static void omap_dma_free_chan_resources(struct dma_chan *chan) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + + vchan_free_chan_resources(&c->vc); + omap_free_dma(c->dma_ch); + + dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig); +} + +static size_t omap_dma_sg_size(struct omap_sg *sg) +{ + return sg->en * sg->fn; +} + +static size_t omap_dma_desc_size(struct omap_desc *d) +{ + unsigned i; + size_t size; + + for (size = i = 0; i < d->sglen; i++) + size += omap_dma_sg_size(&d->sg[i]); + + return size * es_bytes[d->es]; +} + +static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr) +{ + unsigned i; + size_t size, es_size = es_bytes[d->es]; + + for (size = i = 0; i < d->sglen; i++) { + size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size; + + if (size) + size += this_size; + else if (addr >= d->sg[i].addr && + addr < d->sg[i].addr + this_size) + size += d->sg[i].addr + this_size - addr; + } + return size; +} + +static enum dma_status omap_dma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *txstate) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + struct virt_dma_desc *vd; + enum dma_status ret; + unsigned long flags; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_SUCCESS || !txstate) + return ret; + + spin_lock_irqsave(&c->vc.lock, flags); + vd = vchan_find_desc(&c->vc, cookie); + if (vd) { + txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx)); + } else if (c->desc && c->desc->vd.tx.cookie == cookie) { + struct omap_desc *d = c->desc; + dma_addr_t pos; + + if (d->dir == DMA_MEM_TO_DEV) + pos = omap_get_dma_src_pos(c->dma_ch); + else if (d->dir == DMA_DEV_TO_MEM) + pos = omap_get_dma_dst_pos(c->dma_ch); + else + pos = 0; + + txstate->residue = omap_dma_desc_size_pos(d, pos); + } else { + txstate->residue = 0; + } + spin_unlock_irqrestore(&c->vc.lock, flags); + + return ret; +} + +static void omap_dma_issue_pending(struct dma_chan *chan) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&c->vc.lock, flags); + if (vchan_issue_pending(&c->vc) && !c->desc) { + struct omap_dmadev *d = to_omap_dma_dev(chan->device); + spin_lock(&d->lock); + if (list_empty(&c->node)) + list_add_tail(&c->node, &d->pending); + spin_unlock(&d->lock); + tasklet_schedule(&d->task); + } + spin_unlock_irqrestore(&c->vc.lock, flags); +} + +static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen, + enum dma_transfer_direction dir, unsigned long tx_flags, void *context) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + enum dma_slave_buswidth dev_width; + struct scatterlist *sgent; + struct omap_desc *d; + dma_addr_t dev_addr; + unsigned i, j = 0, es, en, frame_bytes, sync_type; + u32 burst; + + if (dir == DMA_DEV_TO_MEM) { + dev_addr = c->cfg.src_addr; + dev_width = c->cfg.src_addr_width; + burst = c->cfg.src_maxburst; + sync_type = OMAP_DMA_SRC_SYNC; + } else if (dir == DMA_MEM_TO_DEV) { + dev_addr = c->cfg.dst_addr; + dev_width = c->cfg.dst_addr_width; + burst = c->cfg.dst_maxburst; + sync_type = OMAP_DMA_DST_SYNC; + } else { + dev_err(chan->device->dev, "%s: bad direction?\n", __func__); + return NULL; + } + + /* Bus width translates to the element size (ES) */ + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + es = OMAP_DMA_DATA_TYPE_S8; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + es = OMAP_DMA_DATA_TYPE_S16; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = OMAP_DMA_DATA_TYPE_S32; + break; + default: /* not reached */ + return NULL; + } + + /* Now allocate and setup the descriptor. */ + d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC); + if (!d) + return NULL; + + d->dir = dir; + d->dev_addr = dev_addr; + d->es = es; + d->sync_mode = OMAP_DMA_SYNC_FRAME; + d->sync_type = sync_type; + d->periph_port = OMAP_DMA_PORT_TIPB; + + /* + * Build our scatterlist entries: each contains the address, + * the number of elements (EN) in each frame, and the number of + * frames (FN). Number of bytes for this entry = ES * EN * FN. + * + * Burst size translates to number of elements with frame sync. + * Note: DMA engine defines burst to be the number of dev-width + * transfers. + */ + en = burst; + frame_bytes = es_bytes[es] * en; + for_each_sg(sgl, sgent, sglen, i) { + d->sg[j].addr = sg_dma_address(sgent); + d->sg[j].en = en; + d->sg[j].fn = sg_dma_len(sgent) / frame_bytes; + j++; + } + + d->sglen = j; + + return vchan_tx_prep(&c->vc, &d->vd, tx_flags); +} + +static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction dir, void *context) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + enum dma_slave_buswidth dev_width; + struct omap_desc *d; + dma_addr_t dev_addr; + unsigned es, sync_type; + u32 burst; + + if (dir == DMA_DEV_TO_MEM) { + dev_addr = c->cfg.src_addr; + dev_width = c->cfg.src_addr_width; + burst = c->cfg.src_maxburst; + sync_type = OMAP_DMA_SRC_SYNC; + } else if (dir == DMA_MEM_TO_DEV) { + dev_addr = c->cfg.dst_addr; + dev_width = c->cfg.dst_addr_width; + burst = c->cfg.dst_maxburst; + sync_type = OMAP_DMA_DST_SYNC; + } else { + dev_err(chan->device->dev, "%s: bad direction?\n", __func__); + return NULL; + } + + /* Bus width translates to the element size (ES) */ + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + es = OMAP_DMA_DATA_TYPE_S8; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + es = OMAP_DMA_DATA_TYPE_S16; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = OMAP_DMA_DATA_TYPE_S32; + break; + default: /* not reached */ + return NULL; + } + + /* Now allocate and setup the descriptor. */ + d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC); + if (!d) + return NULL; + + d->dir = dir; + d->dev_addr = dev_addr; + d->fi = burst; + d->es = es; + d->sync_mode = OMAP_DMA_SYNC_PACKET; + d->sync_type = sync_type; + d->periph_port = OMAP_DMA_PORT_MPUI; + d->sg[0].addr = buf_addr; + d->sg[0].en = period_len / es_bytes[es]; + d->sg[0].fn = buf_len / period_len; + d->sglen = 1; + + if (!c->cyclic) { + c->cyclic = true; + omap_dma_link_lch(c->dma_ch, c->dma_ch); + omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ); + omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ); + } + + if (!cpu_class_is_omap1()) { + omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16); + } + + return vchan_tx_prep(&c->vc, &d->vd, DMA_CTRL_ACK | DMA_PREP_INTERRUPT); +} + +static int omap_dma_slave_config(struct omap_chan *c, 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(&c->cfg, cfg, sizeof(c->cfg)); + + return 0; +} + +static int omap_dma_terminate_all(struct omap_chan *c) +{ + struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&c->vc.lock, flags); + + /* Prevent this channel being scheduled */ + spin_lock(&d->lock); + list_del_init(&c->node); + spin_unlock(&d->lock); + + /* + * Stop DMA activity: we assume the callback will not be called + * after omap_stop_dma() returns (even if it does, it will see + * c->desc is NULL and exit.) + */ + if (c->desc) { + c->desc = NULL; + omap_stop_dma(c->dma_ch); + } + + if (c->cyclic) { + c->cyclic = false; + omap_dma_unlink_lch(c->dma_ch, c->dma_ch); + } + + vchan_get_all_descriptors(&c->vc, &head); + spin_unlock_irqrestore(&c->vc.lock, flags); + vchan_dma_desc_free_list(&c->vc, &head); + + return 0; +} + +static int omap_dma_pause(struct omap_chan *c) +{ + /* FIXME: not supported by platform private API */ + return -EINVAL; +} + +static int omap_dma_resume(struct omap_chan *c) +{ + /* FIXME: not supported by platform private API */ + return -EINVAL; +} + +static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, + unsigned long arg) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + int ret; + + switch (cmd) { + case DMA_SLAVE_CONFIG: + ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg); + break; + + case DMA_TERMINATE_ALL: + ret = omap_dma_terminate_all(c); + break; + + case DMA_PAUSE: + ret = omap_dma_pause(c); + break; + + case DMA_RESUME: + ret = omap_dma_resume(c); + break; + + default: + ret = -ENXIO; + break; + } + + return ret; +} + +static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig) +{ + struct omap_chan *c; + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + c->dma_sig = dma_sig; + c->vc.desc_free = omap_dma_desc_free; + vchan_init(&c->vc, &od->ddev); + INIT_LIST_HEAD(&c->node); + + od->ddev.chancnt++; + + return 0; +} + +static void omap_dma_free(struct omap_dmadev *od) +{ + tasklet_kill(&od->task); + while (!list_empty(&od->ddev.channels)) { + struct omap_chan *c = list_first_entry(&od->ddev.channels, + struct omap_chan, vc.chan.device_node); + + list_del(&c->vc.chan.device_node); + tasklet_kill(&c->vc.task); + kfree(c); + } + kfree(od); +} + +static int omap_dma_probe(struct platform_device *pdev) +{ + struct omap_dmadev *od; + int rc, i; + + od = kzalloc(sizeof(*od), GFP_KERNEL); + if (!od) + return -ENOMEM; + + dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); + od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources; + od->ddev.device_free_chan_resources = omap_dma_free_chan_resources; + od->ddev.device_tx_status = omap_dma_tx_status; + od->ddev.device_issue_pending = omap_dma_issue_pending; + od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg; + od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic; + od->ddev.device_control = omap_dma_control; + od->ddev.dev = &pdev->dev; + INIT_LIST_HEAD(&od->ddev.channels); + INIT_LIST_HEAD(&od->pending); + spin_lock_init(&od->lock); + + tasklet_init(&od->task, omap_dma_sched, (unsigned long)od); + + for (i = 0; i < 127; i++) { + rc = omap_dma_chan_init(od, i); + if (rc) { + omap_dma_free(od); + return rc; + } + } + + rc = dma_async_device_register(&od->ddev); + if (rc) { + pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n", + rc); + omap_dma_free(od); + } else { + platform_set_drvdata(pdev, od); + } + + dev_info(&pdev->dev, "OMAP DMA engine driver\n"); + + return rc; +} + +static int omap_dma_remove(struct platform_device *pdev) +{ + struct omap_dmadev *od = platform_get_drvdata(pdev); + + dma_async_device_unregister(&od->ddev); + omap_dma_free(od); + + return 0; +} + +static struct platform_driver omap_dma_driver = { + .probe = omap_dma_probe, + .remove = omap_dma_remove, + .driver = { + .name = "omap-dma-engine", + .owner = THIS_MODULE, + }, +}; + +bool omap_dma_filter_fn(struct dma_chan *chan, void *param) +{ + if (chan->device->dev->driver == &omap_dma_driver.driver) { + struct omap_chan *c = to_omap_dma_chan(chan); + unsigned req = *(unsigned *)param; + + return req == c->dma_sig; + } + return false; +} +EXPORT_SYMBOL_GPL(omap_dma_filter_fn); + +static struct platform_device *pdev; + +static const struct platform_device_info omap_dma_dev_info = { + .name = "omap-dma-engine", + .id = -1, + .dma_mask = DMA_BIT_MASK(32), +}; + +static int omap_dma_init(void) +{ + int rc = platform_driver_register(&omap_dma_driver); + + if (rc == 0) { + pdev = platform_device_register_full(&omap_dma_dev_info); + if (IS_ERR(pdev)) { + platform_driver_unregister(&omap_dma_driver); + rc = PTR_ERR(pdev); + } + } + return rc; +} +subsys_initcall(omap_dma_init); + +static void __exit omap_dma_exit(void) +{ + platform_device_unregister(pdev); + platform_driver_unregister(&omap_dma_driver); +} +module_exit(omap_dma_exit); + +MODULE_AUTHOR("Russell King"); +MODULE_LICENSE("GPL"); |