/* * Freescale MPC85xx, MPC83xx DMA Engine support * * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved. * * Author: * Zhang Wei <wei.zhang@freescale.com>, Jul 2007 * Ebony Zhu <ebony.zhu@freescale.com>, May 2007 * * Description: * DMA engine driver for Freescale MPC8540 DMA controller, which is * also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc. * The support for MPC8349 DMA contorller is also added. * * This driver instructs the DMA controller to issue the PCI Read Multiple * command for PCI read operations, instead of using the default PCI Read Line * command. Please be aware that this setting may result in read pre-fetching * on some platforms. * * This 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/init.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/dmaengine.h> #include <linux/delay.h> #include <linux/dma-mapping.h> #include <linux/dmapool.h> #include <linux/of_platform.h> #include <asm/fsldma.h> #include "fsldma.h" static void dma_init(struct fsldma_chan *chan) { /* Reset the channel */ DMA_OUT(chan, &chan->regs->mr, 0, 32); switch (chan->feature & FSL_DMA_IP_MASK) { case FSL_DMA_IP_85XX: /* Set the channel to below modes: * EIE - Error interrupt enable * EOSIE - End of segments interrupt enable (basic mode) * EOLNIE - End of links interrupt enable */ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32); break; case FSL_DMA_IP_83XX: /* Set the channel to below modes: * EOTIE - End-of-transfer interrupt enable * PRC_RM - PCI read multiple */ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE | FSL_DMA_MR_PRC_RM, 32); break; } } static void set_sr(struct fsldma_chan *chan, u32 val) { DMA_OUT(chan, &chan->regs->sr, val, 32); } static u32 get_sr(struct fsldma_chan *chan) { return DMA_IN(chan, &chan->regs->sr, 32); } static void set_desc_cnt(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, u32 count) { hw->count = CPU_TO_DMA(chan, count, 32); } static void set_desc_src(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t src) { u64 snoop_bits; snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0; hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64); } static void set_desc_dst(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t dst) { u64 snoop_bits; snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0; hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64); } static void set_desc_next(struct fsldma_chan *chan, struct fsl_dma_ld_hw *hw, dma_addr_t next) { u64 snoop_bits; snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0; hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64); } static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr) { DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64); } static dma_addr_t get_cdar(struct fsldma_chan *chan) { return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN; } static dma_addr_t get_ndar(struct fsldma_chan *chan) { return DMA_IN(chan, &chan->regs->ndar, 64); } static u32 get_bcr(struct fsldma_chan *chan) { return DMA_IN(chan, &chan->regs->bcr, 32); } static int dma_is_idle(struct fsldma_chan *chan) { u32 sr = get_sr(chan); return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH); } static void dma_start(struct fsldma_chan *chan) { u32 mode; mode = DMA_IN(chan, &chan->regs->mr, 32); if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) { if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) { DMA_OUT(chan, &chan->regs->bcr, 0, 32); mode |= FSL_DMA_MR_EMP_EN; } else { mode &= ~FSL_DMA_MR_EMP_EN; } } if (chan->feature & FSL_DMA_CHAN_START_EXT) mode |= FSL_DMA_MR_EMS_EN; else mode |= FSL_DMA_MR_CS; DMA_OUT(chan, &chan->regs->mr, mode, 32); } static void dma_halt(struct fsldma_chan *chan) { u32 mode; int i; mode = DMA_IN(chan, &chan->regs->mr, 32); mode |= FSL_DMA_MR_CA; DMA_OUT(chan, &chan->regs->mr, mode, 32); mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA); DMA_OUT(chan, &chan->regs->mr, mode, 32); for (i = 0; i < 100; i++) { if (dma_is_idle(chan)) return; udelay(10); } if (!dma_is_idle(chan)) dev_err(chan->dev, "DMA halt timeout!\n"); } static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc) { u64 snoop_bits; snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0; desc->hw.next_ln_addr = CPU_TO_DMA(chan, DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL | snoop_bits, 64); } /** * fsl_chan_set_src_loop_size - Set source address hold transfer size * @chan : Freescale DMA channel * @size : Address loop size, 0 for disable loop * * The set source address hold transfer size. The source * address hold or loop transfer size is when the DMA transfer * data from source address (SA), if the loop size is 4, the DMA will * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA, * SA + 1 ... and so on. */ static void fsl_chan_set_src_loop_size(struct fsldma_chan *chan, int size) { u32 mode; mode = DMA_IN(chan, &chan->regs->mr, 32); switch (size) { case 0: mode &= ~FSL_DMA_MR_SAHE; break; case 1: case 2: case 4: case 8: mode |= FSL_DMA_MR_SAHE | (__ilog2(size) << 14); break; } DMA_OUT(chan, &chan->regs->mr, mode, 32); } /** * fsl_chan_set_dst_loop_size - Set destination address hold transfer size * @chan : Freescale DMA channel * @size : Address loop size, 0 for disable loop * * The set destination address hold transfer size. The destination * address hold or loop transfer size is when the DMA transfer * data to destination address (TA), if the loop size is 4, the DMA will * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA, * TA + 1 ... and so on. */ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *chan, int size) { u32 mode; mode = DMA_IN(chan, &chan->regs->mr, 32); switch (size) { case 0: mode &= ~FSL_DMA_MR_DAHE; break; case 1: case 2: case 4: case 8: mode |= FSL_DMA_MR_DAHE | (__ilog2(size) << 16); break; } DMA_OUT(chan, &chan->regs->mr, mode, 32); } /** * fsl_chan_set_request_count - Set DMA Request Count for external control * @chan : Freescale DMA channel * @size : Number of bytes to transfer in a single request * * The Freescale DMA channel can be controlled by the external signal DREQ#. * The DMA request count is how many bytes are allowed to transfer before * pausing the channel, after which a new assertion of DREQ# resumes channel * operation. * * A size of 0 disables external pause control. The maximum size is 1024. */ static void fsl_chan_set_request_count(struct fsldma_chan *chan, int size) { u32 mode; BUG_ON(size > 1024); mode = DMA_IN(chan, &chan->regs->mr, 32); mode |= (__ilog2(size) << 24) & 0x0f000000; DMA_OUT(chan, &chan->regs->mr, mode, 32); } /** * fsl_chan_toggle_ext_pause - Toggle channel external pause status * @chan : Freescale DMA channel * @enable : 0 is disabled, 1 is enabled. * * The Freescale DMA channel can be controlled by the external signal DREQ#. * The DMA Request Count feature should be used in addition to this feature * to set the number of bytes to transfer before pausing the channel. */ static void fsl_chan_toggle_ext_pause(struct fsldma_chan *chan, int enable) { if (enable) chan->feature |= FSL_DMA_CHAN_PAUSE_EXT; else chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT; } /** * fsl_chan_toggle_ext_start - Toggle channel external start status * @chan : Freescale DMA channel * @enable : 0 is disabled, 1 is enabled. * * If enable the external start, the channel can be started by an * external DMA start pin. So the dma_start() does not start the * transfer immediately. The DMA channel will wait for the * control pin asserted. */ static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable) { if (enable) chan->feature |= FSL_DMA_CHAN_START_EXT; else chan->feature &= ~FSL_DMA_CHAN_START_EXT; } static void append_ld_queue(struct fsldma_chan *chan, struct fsl_desc_sw *desc) { struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev); if (list_empty(&chan->ld_pending)) goto out_splice; /* * Add the hardware descriptor to the chain of hardware descriptors * that already exists in memory. * * This will un-set the EOL bit of the existing transaction, and the * last link in this transaction will become the EOL descriptor. */ set_desc_next(chan, &tail->hw, desc->async_tx.phys); /* * Add the software descriptor and all children to the list * of pending transactions */ out_splice: list_splice_tail_init(&desc->tx_list, &chan->ld_pending); } static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) { struct fsldma_chan *chan = to_fsl_chan(tx->chan); struct fsl_desc_sw *desc = tx_to_fsl_desc(tx); struct fsl_desc_sw *child; unsigned long flags; dma_cookie_t cookie; spin_lock_irqsave(&chan->desc_lock, flags); /* * assign cookies to all of the software descriptors * that make up this transaction */ cookie = chan->common.cookie; list_for_each_entry(child, &desc->tx_list, node) { cookie++; if (cookie < 0) cookie = 1; child->async_tx.cookie = cookie; } chan->common.cookie = cookie; /* put this transaction onto the tail of the pending queue */ append_ld_queue(chan, desc); spin_unlock_irqrestore(&chan->desc_lock, flags); return cookie; } /** * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool. * @chan : Freescale DMA channel * * Return - The descriptor allocated. NULL for failed. */ static struct fsl_desc_sw *fsl_dma_alloc_descriptor( struct fsldma_chan *chan) { struct fsl_desc_sw *desc; dma_addr_t pdesc; desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc); if (!desc) { dev_dbg(chan->dev, "out of memory for link desc\n"); return NULL; } memset(desc, 0, sizeof(*desc)); INIT_LIST_HEAD(&desc->tx_list); dma_async_tx_descriptor_init(&desc->async_tx, &chan->common); desc->async_tx.tx_submit = fsl_dma_tx_submit; desc->async_tx.phys = pdesc; return desc; } /** * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel. * @chan : Freescale DMA channel * * This function will create a dma pool for descriptor allocation. * * Return - The number of descriptors allocated. */ static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan) { struct fsldma_chan *chan = to_fsl_chan(dchan); /* Has this channel already been allocated? */ if (chan->desc_pool) return 1; /* * We need the descriptor to be aligned to 32bytes * for meeting FSL DMA specification requirement. */ chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool", chan->dev, sizeof(struct fsl_desc_sw), __alignof__(struct fsl_desc_sw), 0); if (!chan->desc_pool) { dev_err(chan->dev, "unable to allocate channel %d " "descriptor pool\n", chan->id); return -ENOMEM; } /* there is at least one descriptor free to be allocated */ return 1; } /** * fsldma_free_desc_list - Free all descriptors in a queue * @chan: Freescae DMA channel * @list: the list to free * * LOCKING: must hold chan->desc_lock */ static void fsldma_free_desc_list(struct fsldma_chan *chan, struct list_head *list) { struct fsl_desc_sw *desc, *_desc; list_for_each_entry_safe(desc, _desc, list, node) { list_del(&desc->node); dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys); } } static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan, struct list_head *list) { struct fsl_desc_sw *desc, *_desc; list_for_each_entry_safe_reverse(desc, _desc, list, node) { list_del(&desc->node); dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys); } } /** * fsl_dma_free_chan_resources - Free all resources of the channel. * @chan : Freescale DMA channel */ static void fsl_dma_free_chan_resources(struct dma_chan *dchan) { struct fsldma_chan *chan = to_fsl_chan(dchan); unsigned long flags; dev_dbg(chan->dev, "Free all channel resources.\n"); spin_lock_irqsave(&chan->desc_lock, flags); fsldma_free_desc_list(chan, &chan->ld_pending); fsldma_free_desc_list(chan, &chan->ld_running); spin_unlock_irqrestore(&chan->desc_lock, flags); dma_pool_destroy(chan->desc_pool); chan->desc_pool = NULL; } static struct dma_async_tx_descriptor * fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags) { struct fsldma_chan *chan; struct fsl_desc_sw *new; if (!dchan) return NULL; chan = to_fsl_chan(dchan); new = fsl_dma_alloc_descriptor(chan); if (!new) { dev_err(chan->dev, "No free memory for link descriptor\n"); return NULL; } new->async_tx.cookie = -EBUSY; new->async_tx.flags = flags; /* Insert the link descriptor to the LD ring */ list_add_tail(&new->node, &new->tx_list); /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(chan, new); return &new->async_tx; } static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src, size_t len, unsigned long flags) { struct fsldma_chan *chan; struct fsl_desc_sw *first = NULL, *prev = NULL, *new; size_t copy; if (!dchan) return NULL; if (!len) return NULL; chan = to_fsl_chan(dchan); do { /* Allocate the link descriptor from DMA pool */ new = fsl_dma_alloc_descriptor(chan); if (!new) { dev_err(chan->dev, "No free memory for link descriptor\n"); goto fail; } #ifdef FSL_DMA_LD_DEBUG dev_dbg(chan->dev, "new link desc alloc %p\n", new); #endif copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT); set_desc_cnt(chan, &new->hw, copy); set_desc_src(chan, &new->hw, dma_src); set_desc_dst(chan, &new->hw, dma_dst); if (!first) first = new; else set_desc_next(chan, &prev->hw, new->async_tx.phys); new->async_tx.cookie = 0; async_tx_ack(&new->async_tx); prev = new; len -= copy; dma_src += copy; dma_dst += copy; /* Insert the link descriptor to the LD ring */ list_add_tail(&new->node, &first->tx_list); } while (len); new->async_tx.flags = flags; /* client is in control of this ack */ new->async_tx.cookie = -EBUSY; /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(chan, new); return &first->async_tx; fail: if (!first) return NULL; fsldma_free_desc_list_reverse(chan, &first->tx_list); return NULL; } /** * fsl_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction * @chan: DMA channel * @sgl: scatterlist to transfer to/from * @sg_len: number of entries in @scatterlist * @direction: DMA direction * @flags: DMAEngine flags * * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the * DMA_SLAVE API, this gets the device-specific information from the * chan->private variable. */ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg( struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len, enum dma_data_direction direction, unsigned long flags) { struct fsldma_chan *chan; struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL; struct fsl_dma_slave *slave; size_t copy; int i; struct scatterlist *sg; size_t sg_used; size_t hw_used; struct fsl_dma_hw_addr *hw; dma_addr_t dma_dst, dma_src; if (!dchan) return NULL; if (!dchan->private) return NULL; chan = to_fsl_chan(dchan); slave = dchan->private; if (list_empty(&slave->addresses)) return NULL; hw = list_first_entry(&slave->addresses, struct fsl_dma_hw_addr, entry); hw_used = 0; /* * Build the hardware transaction to copy from the scatterlist to * the hardware, or from the hardware to the scatterlist * * If you are copying from the hardware to the scatterlist and it * takes two hardware entries to fill an entire page, then both * hardware entries will be coalesced into the same page * * If you are copying from the scatterlist to the hardware and a * single page can fill two hardware entries, then the data will * be read out of the page into the first hardware entry, and so on */ for_each_sg(sgl, sg, sg_len, i) { sg_used = 0; /* Loop until the entire scatterlist entry is used */ while (sg_used < sg_dma_len(sg)) { /* * If we've used up the current hardware address/length * pair, we need to load a new one * * This is done in a while loop so that descriptors with * length == 0 will be skipped */ while (hw_used >= hw->length) { /* * If the current hardware entry is the last * entry in the list, we're finished */ if (list_is_last(&hw->entry, &slave->addresses)) goto finished; /* Get the next hardware address/length pair */ hw = list_entry(hw->entry.next, struct fsl_dma_hw_addr, entry); hw_used = 0; } /* Allocate the link descriptor from DMA pool */ new = fsl_dma_alloc_descriptor(chan); if (!new) { dev_err(chan->dev, "No free memory for " "link descriptor\n"); goto fail; } #ifdef FSL_DMA_LD_DEBUG dev_dbg(chan->dev, "new link desc alloc %p\n", new); #endif /* * Calculate the maximum number of bytes to transfer, * making sure it is less than the DMA controller limit */ copy = min_t(size_t, sg_dma_len(sg) - sg_used, hw->length - hw_used); copy = min_t(size_t, copy, FSL_DMA_BCR_MAX_CNT); /* * DMA_FROM_DEVICE * from the hardware to the scatterlist * * DMA_TO_DEVICE * from the scatterlist to the hardware */ if (direction == DMA_FROM_DEVICE) { dma_src = hw->address + hw_used; dma_dst = sg_dma_address(sg) + sg_used; } else { dma_src = sg_dma_address(sg) + sg_used; dma_dst = hw->address + hw_used; } /* Fill in the descriptor */ set_desc_cnt(chan, &new->hw, copy); set_desc_src(chan, &new->hw, dma_src); set_desc_dst(chan, &new->hw, dma_dst); /* * If this is not the first descriptor, chain the * current descriptor after the previous descriptor */ if (!first) { first = new; } else { set_desc_next(chan, &prev->hw, new->async_tx.phys); } new->async_tx.cookie = 0; async_tx_ack(&new->async_tx); prev = new; sg_used += copy; hw_used += copy; /* Insert the link descriptor into the LD ring */ list_add_tail(&new->node, &first->tx_list); } } finished: /* All of the hardware address/length pairs had length == 0 */ if (!first || !new) return NULL; new->async_tx.flags = flags; new->async_tx.cookie = -EBUSY; /* Set End-of-link to the last link descriptor of new list */ set_ld_eol(chan, new); /* Enable extra controller features */ if (chan->set_src_loop_size) chan->set_src_loop_size(chan, slave->src_loop_size); if (chan->set_dst_loop_size) chan->set_dst_loop_size(chan, slave->dst_loop_size); if (chan->toggle_ext_start) chan->toggle_ext_start(chan, slave->external_start); if (chan->toggle_ext_pause) chan->toggle_ext_pause(chan, slave->external_pause); if (chan->set_request_count) chan->set_request_count(chan, slave->request_count); return &first->async_tx; fail: /* If first was not set, then we failed to allocate the very first * descriptor, and we're done */ if (!first) return NULL; /* * First is set, so all of the descriptors we allocated have been added * to first->tx_list, INCLUDING "first" itself. Therefore we * must traverse the list backwards freeing each descriptor in turn * * We're re-using variables for the loop, oh well */ fsldma_free_desc_list_reverse(chan, &first->tx_list); return NULL; } static int fsl_dma_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, unsigned long arg) { struct fsldma_chan *chan; unsigned long flags; /* Only supports DMA_TERMINATE_ALL */ if (cmd != DMA_TERMINATE_ALL) return -ENXIO; if (!dchan) return -EINVAL; chan = to_fsl_chan(dchan); /* Halt the DMA engine */ dma_halt(chan); spin_lock_irqsave(&chan->desc_lock, flags); /* Remove and free all of the descriptors in the LD queue */ fsldma_free_desc_list(chan, &chan->ld_pending); fsldma_free_desc_list(chan, &chan->ld_running); spin_unlock_irqrestore(&chan->desc_lock, flags); return 0; } /** * fsl_dma_update_completed_cookie - Update the completed cookie. * @chan : Freescale DMA channel * * CONTEXT: hardirq */ static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan) { struct fsl_desc_sw *desc; unsigned long flags; dma_cookie_t cookie; spin_lock_irqsave(&chan->desc_lock, flags); if (list_empty(&chan->ld_running)) { dev_dbg(chan->dev, "no running descriptors\n"); goto out_unlock; } /* Get the last descriptor, update the cookie to that */ desc = to_fsl_desc(chan->ld_running.prev); if (dma_is_idle(chan)) cookie = desc->async_tx.cookie; else { cookie = desc->async_tx.cookie - 1; if (unlikely(cookie < DMA_MIN_COOKIE)) cookie = DMA_MAX_COOKIE; } chan->completed_cookie = cookie; out_unlock: spin_unlock_irqrestore(&chan->desc_lock, flags); } /** * fsldma_desc_status - Check the status of a descriptor * @chan: Freescale DMA channel * @desc: DMA SW descriptor * * This function will return the status of the given descriptor */ static enum dma_status fsldma_desc_status(struct fsldma_chan *chan, struct fsl_desc_sw *desc) { return dma_async_is_complete(desc->async_tx.cookie, chan->completed_cookie, chan->common.cookie); } /** * fsl_chan_ld_cleanup - Clean up link descriptors * @chan : Freescale DMA channel * * This function clean up the ld_queue of DMA channel. */ static void fsl_chan_ld_cleanup(struct fsldma_chan *chan) { struct fsl_desc_sw *desc, *_desc; unsigned long flags; spin_lock_irqsave(&chan->desc_lock, flags); dev_dbg(chan->dev, "chan completed_cookie = %d\n", chan->completed_cookie); list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) { dma_async_tx_callback callback; void *callback_param; if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS) break; /* Remove from the list of running transactions */ list_del(&desc->node); /* Run the link descriptor callback function */ callback = desc->async_tx.callback; callback_param = desc->async_tx.callback_param; if (callback) { spin_unlock_irqrestore(&chan->desc_lock, flags); dev_dbg(chan->dev, "LD %p callback\n", desc); callback(callback_param); spin_lock_irqsave(&chan->desc_lock, flags); } /* Run any dependencies, then free the descriptor */ dma_run_dependencies(&desc->async_tx); dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys); } spin_unlock_irqrestore(&chan->desc_lock, flags); } /** * fsl_chan_xfer_ld_queue - transfer any pending transactions * @chan : Freescale DMA channel * * This will make sure that any pending transactions will be run. * If the DMA controller is idle, it will be started. Otherwise, * the DMA controller's interrupt handler will start any pending * transactions when it becomes idle. */ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan) { struct fsl_desc_sw *desc; unsigned long flags; spin_lock_irqsave(&chan->desc_lock, flags); /* * If the list of pending descriptors is empty, then we * don't need to do any work at all */ if (list_empty(&chan->ld_pending)) { dev_dbg(chan->dev, "no pending LDs\n"); goto out_unlock; } /* * The DMA controller is not idle, which means the interrupt * handler will start any queued transactions when it runs * at the end of the current transaction */ if (!dma_is_idle(chan)) { dev_dbg(chan->dev, "DMA controller still busy\n"); goto out_unlock; } /* * TODO: * make sure the dma_halt() function really un-wedges the * controller as much as possible */ dma_halt(chan); /* * If there are some link descriptors which have not been * transferred, we need to start the controller */ /* * Move all elements from the queue of pending transactions * onto the list of running transactions */ desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node); list_splice_tail_init(&chan->ld_pending, &chan->ld_running); /* * Program the descriptor's address into the DMA controller, * then start the DMA transaction */ set_cdar(chan, desc->async_tx.phys); dma_start(chan); out_unlock: spin_unlock_irqrestore(&chan->desc_lock, flags); } /** * fsl_dma_memcpy_issue_pending - Issue the DMA start command * @chan : Freescale DMA channel */ static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan) { struct fsldma_chan *chan = to_fsl_chan(dchan); fsl_chan_xfer_ld_queue(chan); } /** * fsl_tx_status - Determine the DMA status * @chan : Freescale DMA channel */ static enum dma_status fsl_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct fsldma_chan *chan = to_fsl_chan(dchan); dma_cookie_t last_used; dma_cookie_t last_complete; fsl_chan_ld_cleanup(chan); last_used = dchan->cookie; last_complete = chan->completed_cookie; dma_set_tx_state(txstate, last_complete, last_used, 0); return dma_async_is_complete(cookie, last_complete, last_used); } /*----------------------------------------------------------------------------*/ /* Interrupt Handling */ /*----------------------------------------------------------------------------*/ static irqreturn_t fsldma_chan_irq(int irq, void *data) { struct fsldma_chan *chan = data; int update_cookie = 0; int xfer_ld_q = 0; u32 stat; /* save and clear the status register */ stat = get_sr(chan); set_sr(chan, stat); dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat); stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH); if (!stat) return IRQ_NONE; if (stat & FSL_DMA_SR_TE) dev_err(chan->dev, "Transfer Error!\n"); /* * Programming Error * The DMA_INTERRUPT async_tx is a NULL transfer, which will * triger a PE interrupt. */ if (stat & FSL_DMA_SR_PE) { dev_dbg(chan->dev, "irq: Programming Error INT\n"); if (get_bcr(chan) == 0) { /* BCR register is 0, this is a DMA_INTERRUPT async_tx. * Now, update the completed cookie, and continue the * next uncompleted transfer. */ update_cookie = 1; xfer_ld_q = 1; } stat &= ~FSL_DMA_SR_PE; } /* * If the link descriptor segment transfer finishes, * we will recycle the used descriptor. */ if (stat & FSL_DMA_SR_EOSI) { dev_dbg(chan->dev, "irq: End-of-segments INT\n"); dev_dbg(chan->dev, "irq: clndar 0x%llx, nlndar 0x%llx\n", (unsigned long long)get_cdar(chan), (unsigned long long)get_ndar(chan)); stat &= ~FSL_DMA_SR_EOSI; update_cookie = 1; } /* * For MPC8349, EOCDI event need to update cookie * and start the next transfer if it exist. */ if (stat & FSL_DMA_SR_EOCDI) { dev_dbg(chan->dev, "irq: End-of-Chain link INT\n"); stat &= ~FSL_DMA_SR_EOCDI; update_cookie = 1; xfer_ld_q = 1; } /* * If it current transfer is the end-of-transfer, * we should clear the Channel Start bit for * prepare next transfer. */ if (stat & FSL_DMA_SR_EOLNI) { dev_dbg(chan->dev, "irq: End-of-link INT\n"); stat &= ~FSL_DMA_SR_EOLNI; xfer_ld_q = 1; } if (update_cookie) fsl_dma_update_completed_cookie(chan); if (xfer_ld_q) fsl_chan_xfer_ld_queue(chan); if (stat) dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat); dev_dbg(chan->dev, "irq: Exit\n"); tasklet_schedule(&chan->tasklet); return IRQ_HANDLED; } static void dma_do_tasklet(unsigned long data) { struct fsldma_chan *chan = (struct fsldma_chan *)data; fsl_chan_ld_cleanup(chan); } static irqreturn_t fsldma_ctrl_irq(int irq, void *data) { struct fsldma_device *fdev = data; struct fsldma_chan *chan; unsigned int handled = 0; u32 gsr, mask; int i; gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs) : in_le32(fdev->regs); mask = 0xff000000; dev_dbg(fdev->dev, "IRQ: gsr 0x%.8x\n", gsr); for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { chan = fdev->chan[i]; if (!chan) continue; if (gsr & mask) { dev_dbg(fdev->dev, "IRQ: chan %d\n", chan->id); fsldma_chan_irq(irq, chan); handled++; } gsr &= ~mask; mask >>= 8; } return IRQ_RETVAL(handled); } static void fsldma_free_irqs(struct fsldma_device *fdev) { struct fsldma_chan *chan; int i; if (fdev->irq != NO_IRQ) { dev_dbg(fdev->dev, "free per-controller IRQ\n"); free_irq(fdev->irq, fdev); return; } for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { chan = fdev->chan[i]; if (chan && chan->irq != NO_IRQ) { dev_dbg(fdev->dev, "free channel %d IRQ\n", chan->id); free_irq(chan->irq, chan); } } } static int fsldma_request_irqs(struct fsldma_device *fdev) { struct fsldma_chan *chan; int ret; int i; /* if we have a per-controller IRQ, use that */ if (fdev->irq != NO_IRQ) { dev_dbg(fdev->dev, "request per-controller IRQ\n"); ret = request_irq(fdev->irq, fsldma_ctrl_irq, IRQF_SHARED, "fsldma-controller", fdev); return ret; } /* no per-controller IRQ, use the per-channel IRQs */ for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { chan = fdev->chan[i]; if (!chan) continue; if (chan->irq == NO_IRQ) { dev_err(fdev->dev, "no interrupts property defined for " "DMA channel %d. Please fix your " "device tree\n", chan->id); ret = -ENODEV; goto out_unwind; } dev_dbg(fdev->dev, "request channel %d IRQ\n", chan->id); ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED, "fsldma-chan", chan); if (ret) { dev_err(fdev->dev, "unable to request IRQ for DMA " "channel %d\n", chan->id); goto out_unwind; } } return 0; out_unwind: for (/* none */; i >= 0; i--) { chan = fdev->chan[i]; if (!chan) continue; if (chan->irq == NO_IRQ) continue; free_irq(chan->irq, chan); } return ret; } /*----------------------------------------------------------------------------*/ /* OpenFirmware Subsystem */ /*----------------------------------------------------------------------------*/ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev, struct device_node *node, u32 feature, const char *compatible) { struct fsldma_chan *chan; struct resource res; int err; /* alloc channel */ chan = kzalloc(sizeof(*chan), GFP_KERNEL); if (!chan) { dev_err(fdev->dev, "no free memory for DMA channels!\n"); err = -ENOMEM; goto out_return; } /* ioremap registers for use */ chan->regs = of_iomap(node, 0); if (!chan->regs) { dev_err(fdev->dev, "unable to ioremap registers\n"); err = -ENOMEM; goto out_free_chan; } err = of_address_to_resource(node, 0, &res); if (err) { dev_err(fdev->dev, "unable to find 'reg' property\n"); goto out_iounmap_regs; } chan->feature = feature; if (!fdev->feature) fdev->feature = chan->feature; /* * If the DMA device's feature is different than the feature * of its channels, report the bug */ WARN_ON(fdev->feature != chan->feature); chan->dev = fdev->dev; chan->id = ((res.start - 0x100) & 0xfff) >> 7; if (chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) { dev_err(fdev->dev, "too many channels for device\n"); err = -EINVAL; goto out_iounmap_regs; } fdev->chan[chan->id] = chan; tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan); /* Initialize the channel */ dma_init(chan); /* Clear cdar registers */ set_cdar(chan, 0); switch (chan->feature & FSL_DMA_IP_MASK) { case FSL_DMA_IP_85XX: chan->toggle_ext_pause = fsl_chan_toggle_ext_pause; case FSL_DMA_IP_83XX: chan->toggle_ext_start = fsl_chan_toggle_ext_start; chan->set_src_loop_size = fsl_chan_set_src_loop_size; chan->set_dst_loop_size = fsl_chan_set_dst_loop_size; chan->set_request_count = fsl_chan_set_request_count; } spin_lock_init(&chan->desc_lock); INIT_LIST_HEAD(&chan->ld_pending); INIT_LIST_HEAD(&chan->ld_running); chan->common.device = &fdev->common; /* find the IRQ line, if it exists in the device tree */ chan->irq = irq_of_parse_and_map(node, 0); /* Add the channel to DMA device channel list */ list_add_tail(&chan->common.device_node, &fdev->common.channels); fdev->common.chancnt++; dev_info(fdev->dev, "#%d (%s), irq %d\n", chan->id, compatible, chan->irq != NO_IRQ ? chan->irq : fdev->irq); return 0; out_iounmap_regs: iounmap(chan->regs); out_free_chan: kfree(chan); out_return: return err; } static void fsl_dma_chan_remove(struct fsldma_chan *chan) { irq_dispose_mapping(chan->irq); list_del(&chan->common.device_node); iounmap(chan->regs); kfree(chan); } static int __devinit fsldma_of_probe(struct of_device *op, const struct of_device_id *match) { struct fsldma_device *fdev; struct device_node *child; int err; fdev = kzalloc(sizeof(*fdev), GFP_KERNEL); if (!fdev) { dev_err(&op->dev, "No enough memory for 'priv'\n"); err = -ENOMEM; goto out_return; } fdev->dev = &op->dev; INIT_LIST_HEAD(&fdev->common.channels); /* ioremap the registers for use */ fdev->regs = of_iomap(op->dev.of_node, 0); if (!fdev->regs) { dev_err(&op->dev, "unable to ioremap registers\n"); err = -ENOMEM; goto out_free_fdev; } /* map the channel IRQ if it exists, but don't hookup the handler yet */ fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0); dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask); dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask); dma_cap_set(DMA_SLAVE, fdev->common.cap_mask); fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources; fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources; fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt; fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy; fdev->common.device_tx_status = fsl_tx_status; fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending; fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg; fdev->common.device_control = fsl_dma_device_control; fdev->common.dev = &op->dev; dev_set_drvdata(&op->dev, fdev); /* * We cannot use of_platform_bus_probe() because there is no * of_platform_bus_remove(). Instead, we manually instantiate every DMA * channel object. */ for_each_child_of_node(op->dev.of_node, child) { if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) { fsl_dma_chan_probe(fdev, child, FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN, "fsl,eloplus-dma-channel"); } if (of_device_is_compatible(child, "fsl,elo-dma-channel")) { fsl_dma_chan_probe(fdev, child, FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN, "fsl,elo-dma-channel"); } } /* * Hookup the IRQ handler(s) * * If we have a per-controller interrupt, we prefer that to the * per-channel interrupts to reduce the number of shared interrupt * handlers on the same IRQ line */ err = fsldma_request_irqs(fdev); if (err) { dev_err(fdev->dev, "unable to request IRQs\n"); goto out_free_fdev; } dma_async_device_register(&fdev->common); return 0; out_free_fdev: irq_dispose_mapping(fdev->irq); kfree(fdev); out_return: return err; } static int fsldma_of_remove(struct of_device *op) { struct fsldma_device *fdev; unsigned int i; fdev = dev_get_drvdata(&op->dev); dma_async_device_unregister(&fdev->common); fsldma_free_irqs(fdev); for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) { if (fdev->chan[i]) fsl_dma_chan_remove(fdev->chan[i]); } iounmap(fdev->regs); dev_set_drvdata(&op->dev, NULL); kfree(fdev); return 0; } static const struct of_device_id fsldma_of_ids[] = { { .compatible = "fsl,eloplus-dma", }, { .compatible = "fsl,elo-dma", }, {} }; static struct of_platform_driver fsldma_of_driver = { .driver = { .name = "fsl-elo-dma", .owner = THIS_MODULE, .of_match_table = fsldma_of_ids, }, .probe = fsldma_of_probe, .remove = fsldma_of_remove, }; /*----------------------------------------------------------------------------*/ /* Module Init / Exit */ /*----------------------------------------------------------------------------*/ static __init int fsldma_init(void) { int ret; pr_info("Freescale Elo / Elo Plus DMA driver\n"); ret = of_register_platform_driver(&fsldma_of_driver); if (ret) pr_err("fsldma: failed to register platform driver\n"); return ret; } static void __exit fsldma_exit(void) { of_unregister_platform_driver(&fsldma_of_driver); } subsys_initcall(fsldma_init); module_exit(fsldma_exit); MODULE_DESCRIPTION("Freescale Elo / Elo Plus DMA driver"); MODULE_LICENSE("GPL");