/* * Freescale MPC85xx, MPC83xx DMA Engine support * * Copyright (C) 2007-2010 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 controller 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_address.h> #include <linux/of_irq.h> #include <linux/of_platform.h> #include "dmaengine.h" #include "fsldma.h" #define chan_dbg(chan, fmt, arg...) \ dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg) #define chan_err(chan, fmt, arg...) \ dev_err(chan->dev, "%s: " fmt, chan->name, ##arg) static const char msg_ld_oom[] = "No free memory for link descriptor"; /* * Register Helpers */ 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_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 u32 get_bcr(struct fsldma_chan *chan) { return DMA_IN(chan, &chan->regs->bcr, 32); } /* * Descriptor Helpers */ 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_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); } /* * DMA Engine Hardware Control Helpers */ 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 * EOLNIE - End of links interrupt enable * BWC - Bandwidth sharing among channels */ DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE, 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 int dma_is_idle(struct fsldma_chan *chan) { u32 sr = get_sr(chan); return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH); } /* * Start the DMA controller * * Preconditions: * - the CDAR register must point to the start descriptor * - the MRn[CS] bit must be cleared */ static void dma_start(struct fsldma_chan *chan) { u32 mode; mode = DMA_IN(chan, &chan->regs->mr, 32); 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_EMS_EN; 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; /* read the mode register */ mode = DMA_IN(chan, &chan->regs->mr, 32); /* * The 85xx controller supports channel abort, which will stop * the current transfer. On 83xx, this bit is the transfer error * mask bit, which should not be changed. */ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) { mode |= FSL_DMA_MR_CA; DMA_OUT(chan, &chan->regs->mr, mode, 32); mode &= ~FSL_DMA_MR_CA; } /* stop the DMA controller */ mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN); DMA_OUT(chan, &chan->regs->mr, mode, 32); /* wait for the DMA controller to become idle */ for (i = 0; i < 100; i++) { if (dma_is_idle(chan)) return; udelay(10); } if (!dma_is_idle(chan)) chan_err(chan, "DMA halt timeout!\n"); } /** * 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 = -EINVAL; spin_lock_irqsave(&chan->desc_lock, flags); /* * assign cookies to all of the software descriptors * that make up this transaction */ list_for_each_entry(child, &desc->tx_list, node) { cookie = dma_cookie_assign(&child->async_tx); } /* 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) { chan_dbg(chan, "out of memory for link descriptor\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; #ifdef FSL_DMA_LD_DEBUG chan_dbg(chan, "LD %p allocated\n", desc); #endif 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(chan->name, chan->dev, sizeof(struct fsl_desc_sw), __alignof__(struct fsl_desc_sw), 0); if (!chan->desc_pool) { chan_err(chan, "unable to allocate descriptor pool\n"); 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); #ifdef FSL_DMA_LD_DEBUG chan_dbg(chan, "LD %p free\n", desc); #endif 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); #ifdef FSL_DMA_LD_DEBUG chan_dbg(chan, "LD %p free\n", desc); #endif 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; chan_dbg(chan, "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) { chan_err(chan, "%s\n", msg_ld_oom); 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) { chan_err(chan, "%s\n", msg_ld_oom); goto fail; } 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; } static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan, struct scatterlist *dst_sg, unsigned int dst_nents, struct scatterlist *src_sg, unsigned int src_nents, unsigned long flags) { struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL; struct fsldma_chan *chan = to_fsl_chan(dchan); size_t dst_avail, src_avail; dma_addr_t dst, src; size_t len; /* basic sanity checks */ if (dst_nents == 0 || src_nents == 0) return NULL; if (dst_sg == NULL || src_sg == NULL) return NULL; /* * TODO: should we check that both scatterlists have the same * TODO: number of bytes in total? Is that really an error? */ /* get prepared for the loop */ dst_avail = sg_dma_len(dst_sg); src_avail = sg_dma_len(src_sg); /* run until we are out of scatterlist entries */ while (true) { /* create the largest transaction possible */ len = min_t(size_t, src_avail, dst_avail); len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT); if (len == 0) goto fetch; dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail; src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail; /* allocate and populate the descriptor */ new = fsl_dma_alloc_descriptor(chan); if (!new) { chan_err(chan, "%s\n", msg_ld_oom); goto fail; } set_desc_cnt(chan, &new->hw, len); set_desc_src(chan, &new->hw, src); set_desc_dst(chan, &new->hw, 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; /* Insert the link descriptor to the LD ring */ list_add_tail(&new->node, &first->tx_list); /* update metadata */ dst_avail -= len; src_avail -= len; fetch: /* fetch the next dst scatterlist entry */ if (dst_avail == 0) { /* no more entries: we're done */ if (dst_nents == 0) break; /* fetch the next entry: if there are no more: done */ dst_sg = sg_next(dst_sg); if (dst_sg == NULL) break; dst_nents--; dst_avail = sg_dma_len(dst_sg); } /* fetch the next src scatterlist entry */ if (src_avail == 0) { /* no more entries: we're done */ if (src_nents == 0) break; /* fetch the next entry: if there are no more: done */ src_sg = sg_next(src_sg); if (src_sg == NULL) break; src_nents--; src_avail = sg_dma_len(src_sg); } } 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 * @context: transaction context (ignored) * * 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_transfer_direction direction, unsigned long flags, void *context) { /* * This operation is not supported on the Freescale DMA controller * * However, we need to provide the function pointer to allow the * device_control() method to work. */ return NULL; } static int fsl_dma_device_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd, unsigned long arg) { struct dma_slave_config *config; struct fsldma_chan *chan; unsigned long flags; int size; if (!dchan) return -EINVAL; chan = to_fsl_chan(dchan); switch (cmd) { case DMA_TERMINATE_ALL: spin_lock_irqsave(&chan->desc_lock, flags); /* Halt the DMA engine */ dma_halt(chan); /* 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); chan->idle = true; spin_unlock_irqrestore(&chan->desc_lock, flags); return 0; case DMA_SLAVE_CONFIG: config = (struct dma_slave_config *)arg; /* make sure the channel supports setting burst size */ if (!chan->set_request_count) return -ENXIO; /* we set the controller burst size depending on direction */ if (config->direction == DMA_MEM_TO_DEV) size = config->dst_addr_width * config->dst_maxburst; else size = config->src_addr_width * config->src_maxburst; chan->set_request_count(chan, size); return 0; case FSLDMA_EXTERNAL_START: /* make sure the channel supports external start */ if (!chan->toggle_ext_start) return -ENXIO; chan->toggle_ext_start(chan, arg); return 0; default: return -ENXIO; } return 0; } /** * fsldma_cleanup_descriptor - cleanup and free a single link descriptor * @chan: Freescale DMA channel * @desc: descriptor to cleanup and free * * This function is used on a descriptor which has been executed by the DMA * controller. It will run any callbacks, submit any dependencies, and then * free the descriptor. */ static void fsldma_cleanup_descriptor(struct fsldma_chan *chan, struct fsl_desc_sw *desc) { struct dma_async_tx_descriptor *txd = &desc->async_tx; /* Run the link descriptor callback function */ if (txd->callback) { #ifdef FSL_DMA_LD_DEBUG chan_dbg(chan, "LD %p callback\n", desc); #endif txd->callback(txd->callback_param); } /* Run any dependencies */ dma_run_dependencies(txd); dma_descriptor_unmap(txd); #ifdef FSL_DMA_LD_DEBUG chan_dbg(chan, "LD %p free\n", desc); #endif dma_pool_free(chan->desc_pool, desc, txd->phys); } /** * fsl_chan_xfer_ld_queue - transfer any pending transactions * @chan : Freescale DMA channel * * HARDWARE STATE: idle * LOCKING: must hold chan->desc_lock */ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan) { struct fsl_desc_sw *desc; /* * 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)) { chan_dbg(chan, "no pending LDs\n"); return; } /* * The DMA controller is not idle, which means that the interrupt * handler will start any queued transactions when it runs after * this transaction finishes */ if (!chan->idle) { chan_dbg(chan, "DMA controller still busy\n"); return; } /* * 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 */ chan_dbg(chan, "idle, starting controller\n"); desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node); list_splice_tail_init(&chan->ld_pending, &chan->ld_running); /* * The 85xx DMA controller doesn't clear the channel start bit * automatically at the end of a transfer. Therefore we must clear * it in software before starting the transfer. */ if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) { u32 mode; mode = DMA_IN(chan, &chan->regs->mr, 32); mode &= ~FSL_DMA_MR_CS; DMA_OUT(chan, &chan->regs->mr, mode, 32); } /* * Program the descriptor's address into the DMA controller, * then start the DMA transaction */ set_cdar(chan, desc->async_tx.phys); get_cdar(chan); dma_start(chan); chan->idle = false; } /** * 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); unsigned long flags; spin_lock_irqsave(&chan->desc_lock, flags); fsl_chan_xfer_ld_queue(chan); spin_unlock_irqrestore(&chan->desc_lock, flags); } /** * 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) { return dma_cookie_status(dchan, cookie, txstate); } /*----------------------------------------------------------------------------*/ /* Interrupt Handling */ /*----------------------------------------------------------------------------*/ static irqreturn_t fsldma_chan_irq(int irq, void *data) { struct fsldma_chan *chan = data; u32 stat; /* save and clear the status register */ stat = get_sr(chan); set_sr(chan, stat); chan_dbg(chan, "irq: stat = 0x%x\n", stat); /* check that this was really our device */ stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH); if (!stat) return IRQ_NONE; if (stat & FSL_DMA_SR_TE) chan_err(chan, "Transfer Error!\n"); /* * Programming Error * The DMA_INTERRUPT async_tx is a NULL transfer, which will * trigger a PE interrupt. */ if (stat & FSL_DMA_SR_PE) { chan_dbg(chan, "irq: Programming Error INT\n"); stat &= ~FSL_DMA_SR_PE; if (get_bcr(chan) != 0) chan_err(chan, "Programming Error!\n"); } /* * For MPC8349, EOCDI event need to update cookie * and start the next transfer if it exist. */ if (stat & FSL_DMA_SR_EOCDI) { chan_dbg(chan, "irq: End-of-Chain link INT\n"); stat &= ~FSL_DMA_SR_EOCDI; } /* * 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) { chan_dbg(chan, "irq: End-of-link INT\n"); stat &= ~FSL_DMA_SR_EOLNI; } /* check that the DMA controller is really idle */ if (!dma_is_idle(chan)) chan_err(chan, "irq: controller not idle!\n"); /* check that we handled all of the bits */ if (stat) chan_err(chan, "irq: unhandled sr 0x%08x\n", stat); /* * Schedule the tasklet to handle all cleanup of the current * transaction. It will start a new transaction if there is * one pending. */ tasklet_schedule(&chan->tasklet); chan_dbg(chan, "irq: Exit\n"); return IRQ_HANDLED; } static void dma_do_tasklet(unsigned long data) { struct fsldma_chan *chan = (struct fsldma_chan *)data; struct fsl_desc_sw *desc, *_desc; LIST_HEAD(ld_cleanup); unsigned long flags; chan_dbg(chan, "tasklet entry\n"); spin_lock_irqsave(&chan->desc_lock, flags); /* update the cookie if we have some descriptors to cleanup */ if (!list_empty(&chan->ld_running)) { dma_cookie_t cookie; desc = to_fsl_desc(chan->ld_running.prev); cookie = desc->async_tx.cookie; dma_cookie_complete(&desc->async_tx); chan_dbg(chan, "completed_cookie=%d\n", cookie); } /* * move the descriptors to a temporary list so we can drop the lock * during the entire cleanup operation */ list_splice_tail_init(&chan->ld_running, &ld_cleanup); /* the hardware is now idle and ready for more */ chan->idle = true; /* * Start any pending transactions automatically * * In the ideal case, we keep the DMA controller busy while we go * ahead and free the descriptors below. */ fsl_chan_xfer_ld_queue(chan); spin_unlock_irqrestore(&chan->desc_lock, flags); /* Run the callback for each descriptor, in order */ list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) { /* Remove from the list of transactions */ list_del(&desc->node); /* Run all cleanup for this descriptor */ fsldma_cleanup_descriptor(chan, desc); } chan_dbg(chan, "tasklet exit\n"); } 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) { chan_dbg(chan, "free per-channel IRQ\n"); 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) { chan_err(chan, "interrupts property missing in device tree\n"); ret = -ENODEV; goto out_unwind; } chan_dbg(chan, "request per-channel IRQ\n"); ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED, "fsldma-chan", chan); if (ret) { chan_err(chan, "unable to request per-channel IRQ\n"); 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 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 & 0xfff) < 0x300 ? ((res.start - 0x100) & 0xfff) >> 7 : ((res.start - 0x200) & 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); snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id); /* 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->idle = true; chan->common.device = &fdev->common; dma_cookie_init(&chan->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 fsldma_of_probe(struct platform_device *op) { 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_SG, 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_prep_dma_sg = fsl_dma_prep_sg; 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; dma_set_mask(&(op->dev), DMA_BIT_MASK(36)); platform_set_drvdata(op, 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 platform_device *op) { struct fsldma_device *fdev; unsigned int i; fdev = platform_get_drvdata(op); 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); kfree(fdev); return 0; } static const struct of_device_id fsldma_of_ids[] = { { .compatible = "fsl,elo3-dma", }, { .compatible = "fsl,eloplus-dma", }, { .compatible = "fsl,elo-dma", }, {} }; static struct 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) { pr_info("Freescale Elo series DMA driver\n"); return platform_driver_register(&fsldma_of_driver); } static void __exit fsldma_exit(void) { platform_driver_unregister(&fsldma_of_driver); } subsys_initcall(fsldma_init); module_exit(fsldma_exit); MODULE_DESCRIPTION("Freescale Elo series DMA driver"); MODULE_LICENSE("GPL");