diff options
Diffstat (limited to 'drivers/dma/fsldma.c')
| -rw-r--r-- | drivers/dma/fsldma.c | 1472 |
1 files changed, 1472 insertions, 0 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c new file mode 100644 index 00000000..8f84761f --- /dev/null +++ b/drivers/dma/fsldma.c @@ -0,0 +1,1472 @@ +/* + * 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_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 u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc) +{ + return DMA_TO_CPU(chan, desc->hw.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 dma_addr_t get_desc_src(struct fsldma_chan *chan, + struct fsl_desc_sw *desc) +{ + u64 snoop_bits; + + snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) + ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0; + return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits; +} + +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 dma_addr_t get_desc_dst(struct fsldma_chan *chan, + struct fsl_desc_sw *desc) +{ + u64 snoop_bits; + + snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) + ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0; + return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits; +} + +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; + + 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; + struct device *dev = chan->common.device->dev; + dma_addr_t src = get_desc_src(chan, desc); + dma_addr_t dst = get_desc_dst(chan, desc); + u32 len = get_desc_cnt(chan, desc); + + /* 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); + + /* Unmap the dst buffer, if requested */ + if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) { + if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE) + dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE); + else + dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE); + } + + /* Unmap the src buffer, if requested */ + if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) { + if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE) + dma_unmap_single(dev, src, len, DMA_TO_DEVICE); + else + dma_unmap_page(dev, src, len, DMA_TO_DEVICE); + } + +#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) +{ + struct fsldma_chan *chan = to_fsl_chan(dchan); + enum dma_status ret; + unsigned long flags; + + spin_lock_irqsave(&chan->desc_lock, flags); + ret = dma_cookie_status(dchan, cookie, txstate); + spin_unlock_irqrestore(&chan->desc_lock, flags); + + return ret; +} + +/*----------------------------------------------------------------------------*/ +/* 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 + * triger 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 __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); + 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 __devinit 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)); + + 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 platform_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 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 / Elo Plus 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 / Elo Plus DMA driver"); +MODULE_LICENSE("GPL"); |