diff options
Diffstat (limited to 'drivers/dma/mpc512x_dma.c')
| -rw-r--r-- | drivers/dma/mpc512x_dma.c | 1089 |
1 files changed, 1089 insertions, 0 deletions
diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c new file mode 100644 index 000000000..e6281e7aa --- /dev/null +++ b/drivers/dma/mpc512x_dma.c @@ -0,0 +1,1089 @@ +/* + * Copyright (C) Freescale Semicondutor, Inc. 2007, 2008. + * Copyright (C) Semihalf 2009 + * Copyright (C) Ilya Yanok, Emcraft Systems 2010 + * Copyright (C) Alexander Popov, Promcontroller 2014 + * + * Written by Piotr Ziecik <kosmo@semihalf.com>. Hardware description + * (defines, structures and comments) was taken from MPC5121 DMA driver + * written by Hongjun Chen <hong-jun.chen@freescale.com>. + * + * Approved as OSADL project by a majority of OSADL members and funded + * by OSADL membership fees in 2009; for details see www.osadl.org. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * The full GNU General Public License is included in this distribution in the + * file called COPYING. + */ + +/* + * MPC512x and MPC8308 DMA driver. It supports + * memory to memory data transfers (tested using dmatest module) and + * data transfers between memory and peripheral I/O memory + * by means of slave scatter/gather with these limitations: + * - chunked transfers (described by s/g lists with more than one item) + * are refused as long as proper support for scatter/gather is missing; + * - transfers on MPC8308 always start from software as this SoC appears + * not to have external request lines for peripheral flow control; + * - only peripheral devices with 4-byte FIFO access register are supported; + * - minimal memory <-> I/O memory transfer chunk is 4 bytes and consequently + * source and destination addresses must be 4-byte aligned + * and transfer size must be aligned on (4 * maxburst) boundary; + */ + +#include <linux/module.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> + +#include <linux/random.h> + +#include "dmaengine.h" + +/* Number of DMA Transfer descriptors allocated per channel */ +#define MPC_DMA_DESCRIPTORS 64 + +/* Macro definitions */ +#define MPC_DMA_TCD_OFFSET 0x1000 + +/* + * Maximum channel counts for individual hardware variants + * and the maximum channel count over all supported controllers, + * used for data structure size + */ +#define MPC8308_DMACHAN_MAX 16 +#define MPC512x_DMACHAN_MAX 64 +#define MPC_DMA_CHANNELS 64 + +/* Arbitration mode of group and channel */ +#define MPC_DMA_DMACR_EDCG (1 << 31) +#define MPC_DMA_DMACR_ERGA (1 << 3) +#define MPC_DMA_DMACR_ERCA (1 << 2) + +/* Error codes */ +#define MPC_DMA_DMAES_VLD (1 << 31) +#define MPC_DMA_DMAES_GPE (1 << 15) +#define MPC_DMA_DMAES_CPE (1 << 14) +#define MPC_DMA_DMAES_ERRCHN(err) \ + (((err) >> 8) & 0x3f) +#define MPC_DMA_DMAES_SAE (1 << 7) +#define MPC_DMA_DMAES_SOE (1 << 6) +#define MPC_DMA_DMAES_DAE (1 << 5) +#define MPC_DMA_DMAES_DOE (1 << 4) +#define MPC_DMA_DMAES_NCE (1 << 3) +#define MPC_DMA_DMAES_SGE (1 << 2) +#define MPC_DMA_DMAES_SBE (1 << 1) +#define MPC_DMA_DMAES_DBE (1 << 0) + +#define MPC_DMA_DMAGPOR_SNOOP_ENABLE (1 << 6) + +#define MPC_DMA_TSIZE_1 0x00 +#define MPC_DMA_TSIZE_2 0x01 +#define MPC_DMA_TSIZE_4 0x02 +#define MPC_DMA_TSIZE_16 0x04 +#define MPC_DMA_TSIZE_32 0x05 + +/* MPC5121 DMA engine registers */ +struct __attribute__ ((__packed__)) mpc_dma_regs { + /* 0x00 */ + u32 dmacr; /* DMA control register */ + u32 dmaes; /* DMA error status */ + /* 0x08 */ + u32 dmaerqh; /* DMA enable request high(channels 63~32) */ + u32 dmaerql; /* DMA enable request low(channels 31~0) */ + u32 dmaeeih; /* DMA enable error interrupt high(ch63~32) */ + u32 dmaeeil; /* DMA enable error interrupt low(ch31~0) */ + /* 0x18 */ + u8 dmaserq; /* DMA set enable request */ + u8 dmacerq; /* DMA clear enable request */ + u8 dmaseei; /* DMA set enable error interrupt */ + u8 dmaceei; /* DMA clear enable error interrupt */ + /* 0x1c */ + u8 dmacint; /* DMA clear interrupt request */ + u8 dmacerr; /* DMA clear error */ + u8 dmassrt; /* DMA set start bit */ + u8 dmacdne; /* DMA clear DONE status bit */ + /* 0x20 */ + u32 dmainth; /* DMA interrupt request high(ch63~32) */ + u32 dmaintl; /* DMA interrupt request low(ch31~0) */ + u32 dmaerrh; /* DMA error high(ch63~32) */ + u32 dmaerrl; /* DMA error low(ch31~0) */ + /* 0x30 */ + u32 dmahrsh; /* DMA hw request status high(ch63~32) */ + u32 dmahrsl; /* DMA hardware request status low(ch31~0) */ + union { + u32 dmaihsa; /* DMA interrupt high select AXE(ch63~32) */ + u32 dmagpor; /* (General purpose register on MPC8308) */ + }; + u32 dmailsa; /* DMA interrupt low select AXE(ch31~0) */ + /* 0x40 ~ 0xff */ + u32 reserve0[48]; /* Reserved */ + /* 0x100 */ + u8 dchpri[MPC_DMA_CHANNELS]; + /* DMA channels(0~63) priority */ +}; + +struct __attribute__ ((__packed__)) mpc_dma_tcd { + /* 0x00 */ + u32 saddr; /* Source address */ + + u32 smod:5; /* Source address modulo */ + u32 ssize:3; /* Source data transfer size */ + u32 dmod:5; /* Destination address modulo */ + u32 dsize:3; /* Destination data transfer size */ + u32 soff:16; /* Signed source address offset */ + + /* 0x08 */ + u32 nbytes; /* Inner "minor" byte count */ + u32 slast; /* Last source address adjustment */ + u32 daddr; /* Destination address */ + + /* 0x14 */ + u32 citer_elink:1; /* Enable channel-to-channel linking on + * minor loop complete + */ + u32 citer_linkch:6; /* Link channel for minor loop complete */ + u32 citer:9; /* Current "major" iteration count */ + u32 doff:16; /* Signed destination address offset */ + + /* 0x18 */ + u32 dlast_sga; /* Last Destination address adjustment/scatter + * gather address + */ + + /* 0x1c */ + u32 biter_elink:1; /* Enable channel-to-channel linking on major + * loop complete + */ + u32 biter_linkch:6; + u32 biter:9; /* Beginning "major" iteration count */ + u32 bwc:2; /* Bandwidth control */ + u32 major_linkch:6; /* Link channel number */ + u32 done:1; /* Channel done */ + u32 active:1; /* Channel active */ + u32 major_elink:1; /* Enable channel-to-channel linking on major + * loop complete + */ + u32 e_sg:1; /* Enable scatter/gather processing */ + u32 d_req:1; /* Disable request */ + u32 int_half:1; /* Enable an interrupt when major counter is + * half complete + */ + u32 int_maj:1; /* Enable an interrupt when major iteration + * count completes + */ + u32 start:1; /* Channel start */ +}; + +struct mpc_dma_desc { + struct dma_async_tx_descriptor desc; + struct mpc_dma_tcd *tcd; + dma_addr_t tcd_paddr; + int error; + struct list_head node; + int will_access_peripheral; +}; + +struct mpc_dma_chan { + struct dma_chan chan; + struct list_head free; + struct list_head prepared; + struct list_head queued; + struct list_head active; + struct list_head completed; + struct mpc_dma_tcd *tcd; + dma_addr_t tcd_paddr; + + /* Settings for access to peripheral FIFO */ + dma_addr_t src_per_paddr; + u32 src_tcd_nunits; + dma_addr_t dst_per_paddr; + u32 dst_tcd_nunits; + + /* Lock for this structure */ + spinlock_t lock; +}; + +struct mpc_dma { + struct dma_device dma; + struct tasklet_struct tasklet; + struct mpc_dma_chan channels[MPC_DMA_CHANNELS]; + struct mpc_dma_regs __iomem *regs; + struct mpc_dma_tcd __iomem *tcd; + int irq; + int irq2; + uint error_status; + int is_mpc8308; + + /* Lock for error_status field in this structure */ + spinlock_t error_status_lock; +}; + +#define DRV_NAME "mpc512x_dma" + +/* Convert struct dma_chan to struct mpc_dma_chan */ +static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c) +{ + return container_of(c, struct mpc_dma_chan, chan); +} + +/* Convert struct dma_chan to struct mpc_dma */ +static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c) +{ + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c); + return container_of(mchan, struct mpc_dma, channels[c->chan_id]); +} + +/* + * Execute all queued DMA descriptors. + * + * Following requirements must be met while calling mpc_dma_execute(): + * a) mchan->lock is acquired, + * b) mchan->active list is empty, + * c) mchan->queued list contains at least one entry. + */ +static void mpc_dma_execute(struct mpc_dma_chan *mchan) +{ + struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan); + struct mpc_dma_desc *first = NULL; + struct mpc_dma_desc *prev = NULL; + struct mpc_dma_desc *mdesc; + int cid = mchan->chan.chan_id; + + while (!list_empty(&mchan->queued)) { + mdesc = list_first_entry(&mchan->queued, + struct mpc_dma_desc, node); + /* + * Grab either several mem-to-mem transfer descriptors + * or one peripheral transfer descriptor, + * don't mix mem-to-mem and peripheral transfer descriptors + * within the same 'active' list. + */ + if (mdesc->will_access_peripheral) { + if (list_empty(&mchan->active)) + list_move_tail(&mdesc->node, &mchan->active); + break; + } else { + list_move_tail(&mdesc->node, &mchan->active); + } + } + + /* Chain descriptors into one transaction */ + list_for_each_entry(mdesc, &mchan->active, node) { + if (!first) + first = mdesc; + + if (!prev) { + prev = mdesc; + continue; + } + + prev->tcd->dlast_sga = mdesc->tcd_paddr; + prev->tcd->e_sg = 1; + mdesc->tcd->start = 1; + + prev = mdesc; + } + + prev->tcd->int_maj = 1; + + /* Send first descriptor in chain into hardware */ + memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd)); + + if (first != prev) + mdma->tcd[cid].e_sg = 1; + + if (mdma->is_mpc8308) { + /* MPC8308, no request lines, software initiated start */ + out_8(&mdma->regs->dmassrt, cid); + } else if (first->will_access_peripheral) { + /* Peripherals involved, start by external request signal */ + out_8(&mdma->regs->dmaserq, cid); + } else { + /* Memory to memory transfer, software initiated start */ + out_8(&mdma->regs->dmassrt, cid); + } +} + +/* Handle interrupt on one half of DMA controller (32 channels) */ +static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off) +{ + struct mpc_dma_chan *mchan; + struct mpc_dma_desc *mdesc; + u32 status = is | es; + int ch; + + while ((ch = fls(status) - 1) >= 0) { + status &= ~(1 << ch); + mchan = &mdma->channels[ch + off]; + + spin_lock(&mchan->lock); + + out_8(&mdma->regs->dmacint, ch + off); + out_8(&mdma->regs->dmacerr, ch + off); + + /* Check error status */ + if (es & (1 << ch)) + list_for_each_entry(mdesc, &mchan->active, node) + mdesc->error = -EIO; + + /* Execute queued descriptors */ + list_splice_tail_init(&mchan->active, &mchan->completed); + if (!list_empty(&mchan->queued)) + mpc_dma_execute(mchan); + + spin_unlock(&mchan->lock); + } +} + +/* Interrupt handler */ +static irqreturn_t mpc_dma_irq(int irq, void *data) +{ + struct mpc_dma *mdma = data; + uint es; + + /* Save error status register */ + es = in_be32(&mdma->regs->dmaes); + spin_lock(&mdma->error_status_lock); + if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0) + mdma->error_status = es; + spin_unlock(&mdma->error_status_lock); + + /* Handle interrupt on each channel */ + if (mdma->dma.chancnt > 32) { + mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth), + in_be32(&mdma->regs->dmaerrh), 32); + } + mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl), + in_be32(&mdma->regs->dmaerrl), 0); + + /* Schedule tasklet */ + tasklet_schedule(&mdma->tasklet); + + return IRQ_HANDLED; +} + +/* process completed descriptors */ +static void mpc_dma_process_completed(struct mpc_dma *mdma) +{ + dma_cookie_t last_cookie = 0; + struct mpc_dma_chan *mchan; + struct mpc_dma_desc *mdesc; + struct dma_async_tx_descriptor *desc; + unsigned long flags; + LIST_HEAD(list); + int i; + + for (i = 0; i < mdma->dma.chancnt; i++) { + mchan = &mdma->channels[i]; + + /* Get all completed descriptors */ + spin_lock_irqsave(&mchan->lock, flags); + if (!list_empty(&mchan->completed)) + list_splice_tail_init(&mchan->completed, &list); + spin_unlock_irqrestore(&mchan->lock, flags); + + if (list_empty(&list)) + continue; + + /* Execute callbacks and run dependencies */ + list_for_each_entry(mdesc, &list, node) { + desc = &mdesc->desc; + + if (desc->callback) + desc->callback(desc->callback_param); + + last_cookie = desc->cookie; + dma_run_dependencies(desc); + } + + /* Free descriptors */ + spin_lock_irqsave(&mchan->lock, flags); + list_splice_tail_init(&list, &mchan->free); + mchan->chan.completed_cookie = last_cookie; + spin_unlock_irqrestore(&mchan->lock, flags); + } +} + +/* DMA Tasklet */ +static void mpc_dma_tasklet(unsigned long data) +{ + struct mpc_dma *mdma = (void *)data; + unsigned long flags; + uint es; + + spin_lock_irqsave(&mdma->error_status_lock, flags); + es = mdma->error_status; + mdma->error_status = 0; + spin_unlock_irqrestore(&mdma->error_status_lock, flags); + + /* Print nice error report */ + if (es) { + dev_err(mdma->dma.dev, + "Hardware reported following error(s) on channel %u:\n", + MPC_DMA_DMAES_ERRCHN(es)); + + if (es & MPC_DMA_DMAES_GPE) + dev_err(mdma->dma.dev, "- Group Priority Error\n"); + if (es & MPC_DMA_DMAES_CPE) + dev_err(mdma->dma.dev, "- Channel Priority Error\n"); + if (es & MPC_DMA_DMAES_SAE) + dev_err(mdma->dma.dev, "- Source Address Error\n"); + if (es & MPC_DMA_DMAES_SOE) + dev_err(mdma->dma.dev, "- Source Offset" + " Configuration Error\n"); + if (es & MPC_DMA_DMAES_DAE) + dev_err(mdma->dma.dev, "- Destination Address" + " Error\n"); + if (es & MPC_DMA_DMAES_DOE) + dev_err(mdma->dma.dev, "- Destination Offset" + " Configuration Error\n"); + if (es & MPC_DMA_DMAES_NCE) + dev_err(mdma->dma.dev, "- NBytes/Citter" + " Configuration Error\n"); + if (es & MPC_DMA_DMAES_SGE) + dev_err(mdma->dma.dev, "- Scatter/Gather" + " Configuration Error\n"); + if (es & MPC_DMA_DMAES_SBE) + dev_err(mdma->dma.dev, "- Source Bus Error\n"); + if (es & MPC_DMA_DMAES_DBE) + dev_err(mdma->dma.dev, "- Destination Bus Error\n"); + } + + mpc_dma_process_completed(mdma); +} + +/* Submit descriptor to hardware */ +static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd) +{ + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan); + struct mpc_dma_desc *mdesc; + unsigned long flags; + dma_cookie_t cookie; + + mdesc = container_of(txd, struct mpc_dma_desc, desc); + + spin_lock_irqsave(&mchan->lock, flags); + + /* Move descriptor to queue */ + list_move_tail(&mdesc->node, &mchan->queued); + + /* If channel is idle, execute all queued descriptors */ + if (list_empty(&mchan->active)) + mpc_dma_execute(mchan); + + /* Update cookie */ + cookie = dma_cookie_assign(txd); + spin_unlock_irqrestore(&mchan->lock, flags); + + return cookie; +} + +/* Alloc channel resources */ +static int mpc_dma_alloc_chan_resources(struct dma_chan *chan) +{ + struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan); + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + struct mpc_dma_desc *mdesc; + struct mpc_dma_tcd *tcd; + dma_addr_t tcd_paddr; + unsigned long flags; + LIST_HEAD(descs); + int i; + + /* Alloc DMA memory for Transfer Control Descriptors */ + tcd = dma_alloc_coherent(mdma->dma.dev, + MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd), + &tcd_paddr, GFP_KERNEL); + if (!tcd) + return -ENOMEM; + + /* Alloc descriptors for this channel */ + for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) { + mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL); + if (!mdesc) { + dev_notice(mdma->dma.dev, "Memory allocation error. " + "Allocated only %u descriptors\n", i); + break; + } + + dma_async_tx_descriptor_init(&mdesc->desc, chan); + mdesc->desc.flags = DMA_CTRL_ACK; + mdesc->desc.tx_submit = mpc_dma_tx_submit; + + mdesc->tcd = &tcd[i]; + mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd)); + + list_add_tail(&mdesc->node, &descs); + } + + /* Return error only if no descriptors were allocated */ + if (i == 0) { + dma_free_coherent(mdma->dma.dev, + MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd), + tcd, tcd_paddr); + return -ENOMEM; + } + + spin_lock_irqsave(&mchan->lock, flags); + mchan->tcd = tcd; + mchan->tcd_paddr = tcd_paddr; + list_splice_tail_init(&descs, &mchan->free); + spin_unlock_irqrestore(&mchan->lock, flags); + + /* Enable Error Interrupt */ + out_8(&mdma->regs->dmaseei, chan->chan_id); + + return 0; +} + +/* Free channel resources */ +static void mpc_dma_free_chan_resources(struct dma_chan *chan) +{ + struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan); + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + struct mpc_dma_desc *mdesc, *tmp; + struct mpc_dma_tcd *tcd; + dma_addr_t tcd_paddr; + unsigned long flags; + LIST_HEAD(descs); + + spin_lock_irqsave(&mchan->lock, flags); + + /* Channel must be idle */ + BUG_ON(!list_empty(&mchan->prepared)); + BUG_ON(!list_empty(&mchan->queued)); + BUG_ON(!list_empty(&mchan->active)); + BUG_ON(!list_empty(&mchan->completed)); + + /* Move data */ + list_splice_tail_init(&mchan->free, &descs); + tcd = mchan->tcd; + tcd_paddr = mchan->tcd_paddr; + + spin_unlock_irqrestore(&mchan->lock, flags); + + /* Free DMA memory used by descriptors */ + dma_free_coherent(mdma->dma.dev, + MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd), + tcd, tcd_paddr); + + /* Free descriptors */ + list_for_each_entry_safe(mdesc, tmp, &descs, node) + kfree(mdesc); + + /* Disable Error Interrupt */ + out_8(&mdma->regs->dmaceei, chan->chan_id); +} + +/* Send all pending descriptor to hardware */ +static void mpc_dma_issue_pending(struct dma_chan *chan) +{ + /* + * We are posting descriptors to the hardware as soon as + * they are ready, so this function does nothing. + */ +} + +/* Check request completion status */ +static enum dma_status +mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + return dma_cookie_status(chan, cookie, txstate); +} + +/* Prepare descriptor for memory to memory copy */ +static struct dma_async_tx_descriptor * +mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src, + size_t len, unsigned long flags) +{ + struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan); + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + struct mpc_dma_desc *mdesc = NULL; + struct mpc_dma_tcd *tcd; + unsigned long iflags; + + /* Get free descriptor */ + spin_lock_irqsave(&mchan->lock, iflags); + if (!list_empty(&mchan->free)) { + mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc, + node); + list_del(&mdesc->node); + } + spin_unlock_irqrestore(&mchan->lock, iflags); + + if (!mdesc) { + /* try to free completed descriptors */ + mpc_dma_process_completed(mdma); + return NULL; + } + + mdesc->error = 0; + mdesc->will_access_peripheral = 0; + tcd = mdesc->tcd; + + /* Prepare Transfer Control Descriptor for this transaction */ + memset(tcd, 0, sizeof(struct mpc_dma_tcd)); + + if (IS_ALIGNED(src | dst | len, 32)) { + tcd->ssize = MPC_DMA_TSIZE_32; + tcd->dsize = MPC_DMA_TSIZE_32; + tcd->soff = 32; + tcd->doff = 32; + } else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) { + /* MPC8308 doesn't support 16 byte transfers */ + tcd->ssize = MPC_DMA_TSIZE_16; + tcd->dsize = MPC_DMA_TSIZE_16; + tcd->soff = 16; + tcd->doff = 16; + } else if (IS_ALIGNED(src | dst | len, 4)) { + tcd->ssize = MPC_DMA_TSIZE_4; + tcd->dsize = MPC_DMA_TSIZE_4; + tcd->soff = 4; + tcd->doff = 4; + } else if (IS_ALIGNED(src | dst | len, 2)) { + tcd->ssize = MPC_DMA_TSIZE_2; + tcd->dsize = MPC_DMA_TSIZE_2; + tcd->soff = 2; + tcd->doff = 2; + } else { + tcd->ssize = MPC_DMA_TSIZE_1; + tcd->dsize = MPC_DMA_TSIZE_1; + tcd->soff = 1; + tcd->doff = 1; + } + + tcd->saddr = src; + tcd->daddr = dst; + tcd->nbytes = len; + tcd->biter = 1; + tcd->citer = 1; + + /* Place descriptor in prepared list */ + spin_lock_irqsave(&mchan->lock, iflags); + list_add_tail(&mdesc->node, &mchan->prepared); + spin_unlock_irqrestore(&mchan->lock, iflags); + + return &mdesc->desc; +} + +static struct dma_async_tx_descriptor * +mpc_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan); + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + struct mpc_dma_desc *mdesc = NULL; + dma_addr_t per_paddr; + u32 tcd_nunits; + struct mpc_dma_tcd *tcd; + unsigned long iflags; + struct scatterlist *sg; + size_t len; + int iter, i; + + /* Currently there is no proper support for scatter/gather */ + if (sg_len != 1) + return NULL; + + if (!is_slave_direction(direction)) + return NULL; + + for_each_sg(sgl, sg, sg_len, i) { + spin_lock_irqsave(&mchan->lock, iflags); + + mdesc = list_first_entry(&mchan->free, + struct mpc_dma_desc, node); + if (!mdesc) { + spin_unlock_irqrestore(&mchan->lock, iflags); + /* Try to free completed descriptors */ + mpc_dma_process_completed(mdma); + return NULL; + } + + list_del(&mdesc->node); + + if (direction == DMA_DEV_TO_MEM) { + per_paddr = mchan->src_per_paddr; + tcd_nunits = mchan->src_tcd_nunits; + } else { + per_paddr = mchan->dst_per_paddr; + tcd_nunits = mchan->dst_tcd_nunits; + } + + spin_unlock_irqrestore(&mchan->lock, iflags); + + if (per_paddr == 0 || tcd_nunits == 0) + goto err_prep; + + mdesc->error = 0; + mdesc->will_access_peripheral = 1; + + /* Prepare Transfer Control Descriptor for this transaction */ + tcd = mdesc->tcd; + + memset(tcd, 0, sizeof(struct mpc_dma_tcd)); + + if (!IS_ALIGNED(sg_dma_address(sg), 4)) + goto err_prep; + + if (direction == DMA_DEV_TO_MEM) { + tcd->saddr = per_paddr; + tcd->daddr = sg_dma_address(sg); + tcd->soff = 0; + tcd->doff = 4; + } else { + tcd->saddr = sg_dma_address(sg); + tcd->daddr = per_paddr; + tcd->soff = 4; + tcd->doff = 0; + } + + tcd->ssize = MPC_DMA_TSIZE_4; + tcd->dsize = MPC_DMA_TSIZE_4; + + len = sg_dma_len(sg); + tcd->nbytes = tcd_nunits * 4; + if (!IS_ALIGNED(len, tcd->nbytes)) + goto err_prep; + + iter = len / tcd->nbytes; + if (iter >= 1 << 15) { + /* len is too big */ + goto err_prep; + } + /* citer_linkch contains the high bits of iter */ + tcd->biter = iter & 0x1ff; + tcd->biter_linkch = iter >> 9; + tcd->citer = tcd->biter; + tcd->citer_linkch = tcd->biter_linkch; + + tcd->e_sg = 0; + tcd->d_req = 1; + + /* Place descriptor in prepared list */ + spin_lock_irqsave(&mchan->lock, iflags); + list_add_tail(&mdesc->node, &mchan->prepared); + spin_unlock_irqrestore(&mchan->lock, iflags); + } + + return &mdesc->desc; + +err_prep: + /* Put the descriptor back */ + spin_lock_irqsave(&mchan->lock, iflags); + list_add_tail(&mdesc->node, &mchan->free); + spin_unlock_irqrestore(&mchan->lock, iflags); + + return NULL; +} + +static int mpc_dma_device_config(struct dma_chan *chan, + struct dma_slave_config *cfg) +{ + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + unsigned long flags; + + /* + * Software constraints: + * - only transfers between a peripheral device and + * memory are supported; + * - only peripheral devices with 4-byte FIFO access register + * are supported; + * - minimal transfer chunk is 4 bytes and consequently + * source and destination addresses must be 4-byte aligned + * and transfer size must be aligned on (4 * maxburst) + * boundary; + * - during the transfer RAM address is being incremented by + * the size of minimal transfer chunk; + * - peripheral port's address is constant during the transfer. + */ + + if (cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES || + cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES || + !IS_ALIGNED(cfg->src_addr, 4) || + !IS_ALIGNED(cfg->dst_addr, 4)) { + return -EINVAL; + } + + spin_lock_irqsave(&mchan->lock, flags); + + mchan->src_per_paddr = cfg->src_addr; + mchan->src_tcd_nunits = cfg->src_maxburst; + mchan->dst_per_paddr = cfg->dst_addr; + mchan->dst_tcd_nunits = cfg->dst_maxburst; + + /* Apply defaults */ + if (mchan->src_tcd_nunits == 0) + mchan->src_tcd_nunits = 1; + if (mchan->dst_tcd_nunits == 0) + mchan->dst_tcd_nunits = 1; + + spin_unlock_irqrestore(&mchan->lock, flags); + + return 0; +} + +static int mpc_dma_device_terminate_all(struct dma_chan *chan) +{ + struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan); + struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan); + unsigned long flags; + + /* Disable channel requests */ + spin_lock_irqsave(&mchan->lock, flags); + + out_8(&mdma->regs->dmacerq, chan->chan_id); + list_splice_tail_init(&mchan->prepared, &mchan->free); + list_splice_tail_init(&mchan->queued, &mchan->free); + list_splice_tail_init(&mchan->active, &mchan->free); + + spin_unlock_irqrestore(&mchan->lock, flags); + + return 0; +} + +static int mpc_dma_probe(struct platform_device *op) +{ + struct device_node *dn = op->dev.of_node; + struct device *dev = &op->dev; + struct dma_device *dma; + struct mpc_dma *mdma; + struct mpc_dma_chan *mchan; + struct resource res; + ulong regs_start, regs_size; + int retval, i; + u8 chancnt; + + mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL); + if (!mdma) { + dev_err(dev, "Memory exhausted!\n"); + retval = -ENOMEM; + goto err; + } + + mdma->irq = irq_of_parse_and_map(dn, 0); + if (mdma->irq == NO_IRQ) { + dev_err(dev, "Error mapping IRQ!\n"); + retval = -EINVAL; + goto err; + } + + if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) { + mdma->is_mpc8308 = 1; + mdma->irq2 = irq_of_parse_and_map(dn, 1); + if (mdma->irq2 == NO_IRQ) { + dev_err(dev, "Error mapping IRQ!\n"); + retval = -EINVAL; + goto err_dispose1; + } + } + + retval = of_address_to_resource(dn, 0, &res); + if (retval) { + dev_err(dev, "Error parsing memory region!\n"); + goto err_dispose2; + } + + regs_start = res.start; + regs_size = resource_size(&res); + + if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) { + dev_err(dev, "Error requesting memory region!\n"); + retval = -EBUSY; + goto err_dispose2; + } + + mdma->regs = devm_ioremap(dev, regs_start, regs_size); + if (!mdma->regs) { + dev_err(dev, "Error mapping memory region!\n"); + retval = -ENOMEM; + goto err_dispose2; + } + + mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs) + + MPC_DMA_TCD_OFFSET); + + retval = request_irq(mdma->irq, &mpc_dma_irq, 0, DRV_NAME, mdma); + if (retval) { + dev_err(dev, "Error requesting IRQ!\n"); + retval = -EINVAL; + goto err_dispose2; + } + + if (mdma->is_mpc8308) { + retval = request_irq(mdma->irq2, &mpc_dma_irq, 0, + DRV_NAME, mdma); + if (retval) { + dev_err(dev, "Error requesting IRQ2!\n"); + retval = -EINVAL; + goto err_free1; + } + } + + spin_lock_init(&mdma->error_status_lock); + + dma = &mdma->dma; + dma->dev = dev; + dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources; + dma->device_free_chan_resources = mpc_dma_free_chan_resources; + dma->device_issue_pending = mpc_dma_issue_pending; + dma->device_tx_status = mpc_dma_tx_status; + dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy; + dma->device_prep_slave_sg = mpc_dma_prep_slave_sg; + dma->device_config = mpc_dma_device_config; + dma->device_terminate_all = mpc_dma_device_terminate_all; + + INIT_LIST_HEAD(&dma->channels); + dma_cap_set(DMA_MEMCPY, dma->cap_mask); + dma_cap_set(DMA_SLAVE, dma->cap_mask); + + if (mdma->is_mpc8308) + chancnt = MPC8308_DMACHAN_MAX; + else + chancnt = MPC512x_DMACHAN_MAX; + + for (i = 0; i < chancnt; i++) { + mchan = &mdma->channels[i]; + + mchan->chan.device = dma; + dma_cookie_init(&mchan->chan); + + INIT_LIST_HEAD(&mchan->free); + INIT_LIST_HEAD(&mchan->prepared); + INIT_LIST_HEAD(&mchan->queued); + INIT_LIST_HEAD(&mchan->active); + INIT_LIST_HEAD(&mchan->completed); + + spin_lock_init(&mchan->lock); + list_add_tail(&mchan->chan.device_node, &dma->channels); + } + + tasklet_init(&mdma->tasklet, mpc_dma_tasklet, (unsigned long)mdma); + + /* + * Configure DMA Engine: + * - Dynamic clock, + * - Round-robin group arbitration, + * - Round-robin channel arbitration. + */ + if (mdma->is_mpc8308) { + /* MPC8308 has 16 channels and lacks some registers */ + out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA); + + /* enable snooping */ + out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE); + /* Disable error interrupts */ + out_be32(&mdma->regs->dmaeeil, 0); + + /* Clear interrupts status */ + out_be32(&mdma->regs->dmaintl, 0xFFFF); + out_be32(&mdma->regs->dmaerrl, 0xFFFF); + } else { + out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG | + MPC_DMA_DMACR_ERGA | MPC_DMA_DMACR_ERCA); + + /* Disable hardware DMA requests */ + out_be32(&mdma->regs->dmaerqh, 0); + out_be32(&mdma->regs->dmaerql, 0); + + /* Disable error interrupts */ + out_be32(&mdma->regs->dmaeeih, 0); + out_be32(&mdma->regs->dmaeeil, 0); + + /* Clear interrupts status */ + out_be32(&mdma->regs->dmainth, 0xFFFFFFFF); + out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF); + out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF); + out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF); + + /* Route interrupts to IPIC */ + out_be32(&mdma->regs->dmaihsa, 0); + out_be32(&mdma->regs->dmailsa, 0); + } + + /* Register DMA engine */ + dev_set_drvdata(dev, mdma); + retval = dma_async_device_register(dma); + if (retval) + goto err_free2; + + /* Register with OF helpers for DMA lookups (nonfatal) */ + if (dev->of_node) { + retval = of_dma_controller_register(dev->of_node, + of_dma_xlate_by_chan_id, mdma); + if (retval) + dev_warn(dev, "Could not register for OF lookup\n"); + } + + return 0; + +err_free2: + if (mdma->is_mpc8308) + free_irq(mdma->irq2, mdma); +err_free1: + free_irq(mdma->irq, mdma); +err_dispose2: + if (mdma->is_mpc8308) + irq_dispose_mapping(mdma->irq2); +err_dispose1: + irq_dispose_mapping(mdma->irq); +err: + return retval; +} + +static int mpc_dma_remove(struct platform_device *op) +{ + struct device *dev = &op->dev; + struct mpc_dma *mdma = dev_get_drvdata(dev); + + if (dev->of_node) + of_dma_controller_free(dev->of_node); + dma_async_device_unregister(&mdma->dma); + if (mdma->is_mpc8308) { + free_irq(mdma->irq2, mdma); + irq_dispose_mapping(mdma->irq2); + } + free_irq(mdma->irq, mdma); + irq_dispose_mapping(mdma->irq); + + return 0; +} + +static const struct of_device_id mpc_dma_match[] = { + { .compatible = "fsl,mpc5121-dma", }, + { .compatible = "fsl,mpc8308-dma", }, + {}, +}; + +static struct platform_driver mpc_dma_driver = { + .probe = mpc_dma_probe, + .remove = mpc_dma_remove, + .driver = { + .name = DRV_NAME, + .of_match_table = mpc_dma_match, + }, +}; + +module_platform_driver(mpc_dma_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>"); |