diff options
Diffstat (limited to 'drivers/dma/pl330.c')
| -rw-r--r-- | drivers/dma/pl330.c | 866 |
1 files changed, 866 insertions, 0 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c new file mode 100644 index 0000000..7c50f6d --- /dev/null +++ b/drivers/dma/pl330.c @@ -0,0 +1,866 @@ +/* linux/drivers/dma/pl330.c + * + * Copyright (C) 2010 Samsung Electronics Co. Ltd. + * Jaswinder Singh <jassi.brar@samsung.com> + * + * 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. + */ + +#include <linux/io.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/amba/bus.h> +#include <linux/amba/pl330.h> + +#define NR_DEFAULT_DESC 16 + +enum desc_status { + /* In the DMAC pool */ + FREE, + /* + * Allocted to some channel during prep_xxx + * Also may be sitting on the work_list. + */ + PREP, + /* + * Sitting on the work_list and already submitted + * to the PL330 core. Not more than two descriptors + * of a channel can be BUSY at any time. + */ + BUSY, + /* + * Sitting on the channel work_list but xfer done + * by PL330 core + */ + DONE, +}; + +struct dma_pl330_chan { + /* Schedule desc completion */ + struct tasklet_struct task; + + /* DMA-Engine Channel */ + struct dma_chan chan; + + /* Last completed cookie */ + dma_cookie_t completed; + + /* List of to be xfered descriptors */ + struct list_head work_list; + + /* Pointer to the DMAC that manages this channel, + * NULL if the channel is available to be acquired. + * As the parent, this DMAC also provides descriptors + * to the channel. + */ + struct dma_pl330_dmac *dmac; + + /* To protect channel manipulation */ + spinlock_t lock; + + /* Token of a hardware channel thread of PL330 DMAC + * NULL if the channel is available to be acquired. + */ + void *pl330_chid; +}; + +struct dma_pl330_dmac { + struct pl330_info pif; + + /* DMA-Engine Device */ + struct dma_device ddma; + + /* Pool of descriptors available for the DMAC's channels */ + struct list_head desc_pool; + /* To protect desc_pool manipulation */ + spinlock_t pool_lock; + + /* Peripheral channels connected to this DMAC */ + struct dma_pl330_chan peripherals[0]; /* keep at end */ +}; + +struct dma_pl330_desc { + /* To attach to a queue as child */ + struct list_head node; + + /* Descriptor for the DMA Engine API */ + struct dma_async_tx_descriptor txd; + + /* Xfer for PL330 core */ + struct pl330_xfer px; + + struct pl330_reqcfg rqcfg; + struct pl330_req req; + + enum desc_status status; + + /* The channel which currently holds this desc */ + struct dma_pl330_chan *pchan; +}; + +static inline struct dma_pl330_chan * +to_pchan(struct dma_chan *ch) +{ + if (!ch) + return NULL; + + return container_of(ch, struct dma_pl330_chan, chan); +} + +static inline struct dma_pl330_desc * +to_desc(struct dma_async_tx_descriptor *tx) +{ + return container_of(tx, struct dma_pl330_desc, txd); +} + +static inline void free_desc_list(struct list_head *list) +{ + struct dma_pl330_dmac *pdmac; + struct dma_pl330_desc *desc; + struct dma_pl330_chan *pch; + unsigned long flags; + + if (list_empty(list)) + return; + + /* Finish off the work list */ + list_for_each_entry(desc, list, node) { + dma_async_tx_callback callback; + void *param; + + /* All desc in a list belong to same channel */ + pch = desc->pchan; + callback = desc->txd.callback; + param = desc->txd.callback_param; + + if (callback) + callback(param); + + desc->pchan = NULL; + } + + pdmac = pch->dmac; + + spin_lock_irqsave(&pdmac->pool_lock, flags); + list_splice_tail_init(list, &pdmac->desc_pool); + spin_unlock_irqrestore(&pdmac->pool_lock, flags); +} + +static inline void fill_queue(struct dma_pl330_chan *pch) +{ + struct dma_pl330_desc *desc; + int ret; + + list_for_each_entry(desc, &pch->work_list, node) { + + /* If already submitted */ + if (desc->status == BUSY) + break; + + ret = pl330_submit_req(pch->pl330_chid, + &desc->req); + if (!ret) { + desc->status = BUSY; + break; + } else if (ret == -EAGAIN) { + /* QFull or DMAC Dying */ + break; + } else { + /* Unacceptable request */ + desc->status = DONE; + dev_err(pch->dmac->pif.dev, "%s:%d Bad Desc(%d)\n", + __func__, __LINE__, desc->txd.cookie); + tasklet_schedule(&pch->task); + } + } +} + +static void pl330_tasklet(unsigned long data) +{ + struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data; + struct dma_pl330_desc *desc, *_dt; + unsigned long flags; + LIST_HEAD(list); + + spin_lock_irqsave(&pch->lock, flags); + + /* Pick up ripe tomatoes */ + list_for_each_entry_safe(desc, _dt, &pch->work_list, node) + if (desc->status == DONE) { + pch->completed = desc->txd.cookie; + list_move_tail(&desc->node, &list); + } + + /* Try to submit a req imm. next to the last completed cookie */ + fill_queue(pch); + + /* Make sure the PL330 Channel thread is active */ + pl330_chan_ctrl(pch->pl330_chid, PL330_OP_START); + + spin_unlock_irqrestore(&pch->lock, flags); + + free_desc_list(&list); +} + +static void dma_pl330_rqcb(void *token, enum pl330_op_err err) +{ + struct dma_pl330_desc *desc = token; + struct dma_pl330_chan *pch = desc->pchan; + unsigned long flags; + + /* If desc aborted */ + if (!pch) + return; + + spin_lock_irqsave(&pch->lock, flags); + + desc->status = DONE; + + spin_unlock_irqrestore(&pch->lock, flags); + + tasklet_schedule(&pch->task); +} + +static int pl330_alloc_chan_resources(struct dma_chan *chan) +{ + struct dma_pl330_chan *pch = to_pchan(chan); + struct dma_pl330_dmac *pdmac = pch->dmac; + unsigned long flags; + + spin_lock_irqsave(&pch->lock, flags); + + pch->completed = chan->cookie = 1; + + pch->pl330_chid = pl330_request_channel(&pdmac->pif); + if (!pch->pl330_chid) { + spin_unlock_irqrestore(&pch->lock, flags); + return 0; + } + + tasklet_init(&pch->task, pl330_tasklet, (unsigned long) pch); + + spin_unlock_irqrestore(&pch->lock, flags); + + return 1; +} + +static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg) +{ + struct dma_pl330_chan *pch = to_pchan(chan); + struct dma_pl330_desc *desc; + unsigned long flags; + + /* Only supports DMA_TERMINATE_ALL */ + if (cmd != DMA_TERMINATE_ALL) + return -ENXIO; + + spin_lock_irqsave(&pch->lock, flags); + + /* FLUSH the PL330 Channel thread */ + pl330_chan_ctrl(pch->pl330_chid, PL330_OP_FLUSH); + + /* Mark all desc done */ + list_for_each_entry(desc, &pch->work_list, node) + desc->status = DONE; + + spin_unlock_irqrestore(&pch->lock, flags); + + pl330_tasklet((unsigned long) pch); + + return 0; +} + +static void pl330_free_chan_resources(struct dma_chan *chan) +{ + struct dma_pl330_chan *pch = to_pchan(chan); + unsigned long flags; + + spin_lock_irqsave(&pch->lock, flags); + + tasklet_kill(&pch->task); + + pl330_release_channel(pch->pl330_chid); + pch->pl330_chid = NULL; + + spin_unlock_irqrestore(&pch->lock, flags); +} + +static enum dma_status +pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct dma_pl330_chan *pch = to_pchan(chan); + dma_cookie_t last_done, last_used; + int ret; + + last_done = pch->completed; + last_used = chan->cookie; + + ret = dma_async_is_complete(cookie, last_done, last_used); + + dma_set_tx_state(txstate, last_done, last_used, 0); + + return ret; +} + +static void pl330_issue_pending(struct dma_chan *chan) +{ + pl330_tasklet((unsigned long) to_pchan(chan)); +} + +/* + * We returned the last one of the circular list of descriptor(s) + * from prep_xxx, so the argument to submit corresponds to the last + * descriptor of the list. + */ +static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct dma_pl330_desc *desc, *last = to_desc(tx); + struct dma_pl330_chan *pch = to_pchan(tx->chan); + dma_cookie_t cookie; + unsigned long flags; + + spin_lock_irqsave(&pch->lock, flags); + + /* Assign cookies to all nodes */ + cookie = tx->chan->cookie; + + while (!list_empty(&last->node)) { + desc = list_entry(last->node.next, struct dma_pl330_desc, node); + + if (++cookie < 0) + cookie = 1; + desc->txd.cookie = cookie; + + list_move_tail(&desc->node, &pch->work_list); + } + + if (++cookie < 0) + cookie = 1; + last->txd.cookie = cookie; + + list_add_tail(&last->node, &pch->work_list); + + tx->chan->cookie = cookie; + + spin_unlock_irqrestore(&pch->lock, flags); + + return cookie; +} + +static inline void _init_desc(struct dma_pl330_desc *desc) +{ + desc->pchan = NULL; + desc->req.x = &desc->px; + desc->req.token = desc; + desc->rqcfg.swap = SWAP_NO; + desc->rqcfg.privileged = 0; + desc->rqcfg.insnaccess = 0; + desc->rqcfg.scctl = SCCTRL0; + desc->rqcfg.dcctl = DCCTRL0; + desc->req.cfg = &desc->rqcfg; + desc->req.xfer_cb = dma_pl330_rqcb; + desc->txd.tx_submit = pl330_tx_submit; + + INIT_LIST_HEAD(&desc->node); +} + +/* Returns the number of descriptors added to the DMAC pool */ +int add_desc(struct dma_pl330_dmac *pdmac, gfp_t flg, int count) +{ + struct dma_pl330_desc *desc; + unsigned long flags; + int i; + + if (!pdmac) + return 0; + + desc = kmalloc(count * sizeof(*desc), flg); + if (!desc) + return 0; + + spin_lock_irqsave(&pdmac->pool_lock, flags); + + for (i = 0; i < count; i++) { + _init_desc(&desc[i]); + list_add_tail(&desc[i].node, &pdmac->desc_pool); + } + + spin_unlock_irqrestore(&pdmac->pool_lock, flags); + + return count; +} + +static struct dma_pl330_desc * +pluck_desc(struct dma_pl330_dmac *pdmac) +{ + struct dma_pl330_desc *desc = NULL; + unsigned long flags; + + if (!pdmac) + return NULL; + + spin_lock_irqsave(&pdmac->pool_lock, flags); + + if (!list_empty(&pdmac->desc_pool)) { + desc = list_entry(pdmac->desc_pool.next, + struct dma_pl330_desc, node); + + list_del_init(&desc->node); + + desc->status = PREP; + desc->txd.callback = NULL; + } + + spin_unlock_irqrestore(&pdmac->pool_lock, flags); + + return desc; +} + +static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch) +{ + struct dma_pl330_dmac *pdmac = pch->dmac; + struct dma_pl330_peri *peri = pch->chan.private; + struct dma_pl330_desc *desc; + + /* Pluck one desc from the pool of DMAC */ + desc = pluck_desc(pdmac); + + /* If the DMAC pool is empty, alloc new */ + if (!desc) { + if (!add_desc(pdmac, GFP_ATOMIC, 1)) + return NULL; + + /* Try again */ + desc = pluck_desc(pdmac); + if (!desc) { + dev_err(pch->dmac->pif.dev, + "%s:%d ALERT!\n", __func__, __LINE__); + return NULL; + } + } + + /* Initialize the descriptor */ + desc->pchan = pch; + desc->txd.cookie = 0; + async_tx_ack(&desc->txd); + + desc->req.rqtype = peri->rqtype; + desc->req.peri = peri->peri_id; + + dma_async_tx_descriptor_init(&desc->txd, &pch->chan); + + return desc; +} + +static inline void fill_px(struct pl330_xfer *px, + dma_addr_t dst, dma_addr_t src, size_t len) +{ + px->next = NULL; + px->bytes = len; + px->dst_addr = dst; + px->src_addr = src; +} + +static struct dma_pl330_desc * +__pl330_prep_dma_memcpy(struct dma_pl330_chan *pch, dma_addr_t dst, + dma_addr_t src, size_t len) +{ + struct dma_pl330_desc *desc = pl330_get_desc(pch); + + if (!desc) { + dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n", + __func__, __LINE__); + return NULL; + } + + /* + * Ideally we should lookout for reqs bigger than + * those that can be programmed with 256 bytes of + * MC buffer, but considering a req size is seldom + * going to be word-unaligned and more than 200MB, + * we take it easy. + * Also, should the limit is reached we'd rather + * have the platform increase MC buffer size than + * complicating this API driver. + */ + fill_px(&desc->px, dst, src, len); + + return desc; +} + +/* Call after fixing burst size */ +static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) +{ + struct dma_pl330_chan *pch = desc->pchan; + struct pl330_info *pi = &pch->dmac->pif; + int burst_len; + + burst_len = pi->pcfg.data_bus_width / 8; + burst_len *= pi->pcfg.data_buf_dep; + burst_len >>= desc->rqcfg.brst_size; + + /* src/dst_burst_len can't be more than 16 */ + if (burst_len > 16) + burst_len = 16; + + while (burst_len > 1) { + if (!(len % (burst_len << desc->rqcfg.brst_size))) + break; + burst_len--; + } + + return burst_len; +} + +static struct dma_async_tx_descriptor * +pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, + dma_addr_t src, size_t len, unsigned long flags) +{ + struct dma_pl330_desc *desc; + struct dma_pl330_chan *pch = to_pchan(chan); + struct dma_pl330_peri *peri = chan->private; + struct pl330_info *pi; + int burst; + + if (unlikely(!pch || !len || !peri)) + return NULL; + + if (peri->rqtype != MEMTOMEM) + return NULL; + + pi = &pch->dmac->pif; + + desc = __pl330_prep_dma_memcpy(pch, dst, src, len); + if (!desc) + return NULL; + + desc->rqcfg.src_inc = 1; + desc->rqcfg.dst_inc = 1; + + /* Select max possible burst size */ + burst = pi->pcfg.data_bus_width / 8; + + while (burst > 1) { + if (!(len % burst)) + break; + burst /= 2; + } + + desc->rqcfg.brst_size = 0; + while (burst != (1 << desc->rqcfg.brst_size)) + desc->rqcfg.brst_size++; + + desc->rqcfg.brst_len = get_burst_len(desc, len); + + desc->txd.flags = flags; + + return &desc->txd; +} + +static struct dma_async_tx_descriptor * +pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_data_direction direction, + unsigned long flg) +{ + struct dma_pl330_desc *first, *desc = NULL; + struct dma_pl330_chan *pch = to_pchan(chan); + struct dma_pl330_peri *peri = chan->private; + struct scatterlist *sg; + unsigned long flags; + int i, burst_size; + dma_addr_t addr; + + if (unlikely(!pch || !sgl || !sg_len)) + return NULL; + + /* Make sure the direction is consistent */ + if ((direction == DMA_TO_DEVICE && + peri->rqtype != MEMTODEV) || + (direction == DMA_FROM_DEVICE && + peri->rqtype != DEVTOMEM)) { + dev_err(pch->dmac->pif.dev, "%s:%d Invalid Direction\n", + __func__, __LINE__); + return NULL; + } + + addr = peri->fifo_addr; + burst_size = peri->burst_sz; + + first = NULL; + + for_each_sg(sgl, sg, sg_len, i) { + + desc = pl330_get_desc(pch); + if (!desc) { + struct dma_pl330_dmac *pdmac = pch->dmac; + + dev_err(pch->dmac->pif.dev, + "%s:%d Unable to fetch desc\n", + __func__, __LINE__); + if (!first) + return NULL; + + spin_lock_irqsave(&pdmac->pool_lock, flags); + + while (!list_empty(&first->node)) { + desc = list_entry(first->node.next, + struct dma_pl330_desc, node); + list_move_tail(&desc->node, &pdmac->desc_pool); + } + + list_move_tail(&first->node, &pdmac->desc_pool); + + spin_unlock_irqrestore(&pdmac->pool_lock, flags); + + return NULL; + } + + if (!first) + first = desc; + else + list_add_tail(&desc->node, &first->node); + + if (direction == DMA_TO_DEVICE) { + desc->rqcfg.src_inc = 1; + desc->rqcfg.dst_inc = 0; + fill_px(&desc->px, + addr, sg_dma_address(sg), sg_dma_len(sg)); + } else { + desc->rqcfg.src_inc = 0; + desc->rqcfg.dst_inc = 1; + fill_px(&desc->px, + sg_dma_address(sg), addr, sg_dma_len(sg)); + } + + desc->rqcfg.brst_size = burst_size; + desc->rqcfg.brst_len = 1; + } + + /* Return the last desc in the chain */ + desc->txd.flags = flg; + return &desc->txd; +} + +static irqreturn_t pl330_irq_handler(int irq, void *data) +{ + if (pl330_update(data)) + return IRQ_HANDLED; + else + return IRQ_NONE; +} + +static int __devinit +pl330_probe(struct amba_device *adev, struct amba_id *id) +{ + struct dma_pl330_platdata *pdat; + struct dma_pl330_dmac *pdmac; + struct dma_pl330_chan *pch; + struct pl330_info *pi; + struct dma_device *pd; + struct resource *res; + int i, ret, irq; + + pdat = adev->dev.platform_data; + + if (!pdat || !pdat->nr_valid_peri) { + dev_err(&adev->dev, "platform data missing\n"); + return -ENODEV; + } + + /* Allocate a new DMAC and its Channels */ + pdmac = kzalloc(pdat->nr_valid_peri * sizeof(*pch) + + sizeof(*pdmac), GFP_KERNEL); + if (!pdmac) { + dev_err(&adev->dev, "unable to allocate mem\n"); + return -ENOMEM; + } + + pi = &pdmac->pif; + pi->dev = &adev->dev; + pi->pl330_data = NULL; + pi->mcbufsz = pdat->mcbuf_sz; + + res = &adev->res; + request_mem_region(res->start, resource_size(res), "dma-pl330"); + + pi->base = ioremap(res->start, resource_size(res)); + if (!pi->base) { + ret = -ENXIO; + goto probe_err1; + } + + irq = adev->irq[0]; + ret = request_irq(irq, pl330_irq_handler, 0, + dev_name(&adev->dev), pi); + if (ret) + goto probe_err2; + + ret = pl330_add(pi); + if (ret) + goto probe_err3; + + INIT_LIST_HEAD(&pdmac->desc_pool); + spin_lock_init(&pdmac->pool_lock); + + /* Create a descriptor pool of default size */ + if (!add_desc(pdmac, GFP_KERNEL, NR_DEFAULT_DESC)) + dev_warn(&adev->dev, "unable to allocate desc\n"); + + pd = &pdmac->ddma; + INIT_LIST_HEAD(&pd->channels); + + /* Initialize channel parameters */ + for (i = 0; i < pdat->nr_valid_peri; i++) { + struct dma_pl330_peri *peri = &pdat->peri[i]; + pch = &pdmac->peripherals[i]; + + switch (peri->rqtype) { + case MEMTOMEM: + dma_cap_set(DMA_MEMCPY, pd->cap_mask); + break; + case MEMTODEV: + case DEVTOMEM: + dma_cap_set(DMA_SLAVE, pd->cap_mask); + break; + default: + dev_err(&adev->dev, "DEVTODEV Not Supported\n"); + continue; + } + + INIT_LIST_HEAD(&pch->work_list); + spin_lock_init(&pch->lock); + pch->pl330_chid = NULL; + pch->chan.private = peri; + pch->chan.device = pd; + pch->chan.chan_id = i; + pch->dmac = pdmac; + + /* Add the channel to the DMAC list */ + pd->chancnt++; + list_add_tail(&pch->chan.device_node, &pd->channels); + } + + pd->dev = &adev->dev; + + pd->device_alloc_chan_resources = pl330_alloc_chan_resources; + pd->device_free_chan_resources = pl330_free_chan_resources; + pd->device_prep_dma_memcpy = pl330_prep_dma_memcpy; + pd->device_tx_status = pl330_tx_status; + pd->device_prep_slave_sg = pl330_prep_slave_sg; + pd->device_control = pl330_control; + pd->device_issue_pending = pl330_issue_pending; + + ret = dma_async_device_register(pd); + if (ret) { + dev_err(&adev->dev, "unable to register DMAC\n"); + goto probe_err4; + } + + amba_set_drvdata(adev, pdmac); + + dev_info(&adev->dev, + "Loaded driver for PL330 DMAC-%d\n", adev->periphid); + dev_info(&adev->dev, + "\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n", + pi->pcfg.data_buf_dep, + pi->pcfg.data_bus_width / 8, pi->pcfg.num_chan, + pi->pcfg.num_peri, pi->pcfg.num_events); + + return 0; + +probe_err4: + pl330_del(pi); +probe_err3: + free_irq(irq, pi); +probe_err2: + iounmap(pi->base); +probe_err1: + release_mem_region(res->start, resource_size(res)); + kfree(pdmac); + + return ret; +} + +static int __devexit pl330_remove(struct amba_device *adev) +{ + struct dma_pl330_dmac *pdmac = amba_get_drvdata(adev); + struct dma_pl330_chan *pch, *_p; + struct pl330_info *pi; + struct resource *res; + int irq; + + if (!pdmac) + return 0; + + amba_set_drvdata(adev, NULL); + + /* Idle the DMAC */ + list_for_each_entry_safe(pch, _p, &pdmac->ddma.channels, + chan.device_node) { + + /* Remove the channel */ + list_del(&pch->chan.device_node); + + /* Flush the channel */ + pl330_control(&pch->chan, DMA_TERMINATE_ALL, 0); + pl330_free_chan_resources(&pch->chan); + } + + pi = &pdmac->pif; + + pl330_del(pi); + + irq = adev->irq[0]; + free_irq(irq, pi); + + iounmap(pi->base); + + res = &adev->res; + release_mem_region(res->start, resource_size(res)); + + kfree(pdmac); + + return 0; +} + +static struct amba_id pl330_ids[] = { + { + .id = 0x00041330, + .mask = 0x000fffff, + }, + { 0, 0 }, +}; + +static struct amba_driver pl330_driver = { + .drv = { + .owner = THIS_MODULE, + .name = "dma-pl330", + }, + .id_table = pl330_ids, + .probe = pl330_probe, + .remove = pl330_remove, +}; + +static int __init pl330_init(void) +{ + return amba_driver_register(&pl330_driver); +} +module_init(pl330_init); + +static void __exit pl330_exit(void) +{ + amba_driver_unregister(&pl330_driver); + return; +} +module_exit(pl330_exit); + +MODULE_AUTHOR("Jaswinder Singh <jassi.brar@samsung.com>"); +MODULE_DESCRIPTION("API Driver for PL330 DMAC"); +MODULE_LICENSE("GPL"); |
