From ce3d899b0ed284a6e901fb6f4a459fdcf003cadb Mon Sep 17 00:00:00 2001 From: Florian Meier Date: Fri, 22 Nov 2013 14:22:53 +0100 Subject: [PATCH 029/114] dmaengine: Add support for BCM2708 Add support for DMA controller of BCM2708 as used in the Raspberry Pi. Currently it only supports cyclic DMA. Signed-off-by: Florian Meier dmaengine: expand functionality by supporting scatter/gather transfers sdhci-bcm2708 and dma.c: fix for LITE channels DMA: fix cyclic LITE length overflow bug --- arch/arm/mach-bcm2708/dma.c | 2 + arch/arm/mach-bcm2708/include/mach/dma.h | 6 +- drivers/dma/Kconfig | 6 + drivers/dma/Makefile | 1 + drivers/dma/bcm2708-dmaengine.c | 1052 ++++++++++++++++++++++++++++++ 5 files changed, 1066 insertions(+), 1 deletion(-) create mode 100644 drivers/dma/bcm2708-dmaengine.c --- a/arch/arm/mach-bcm2708/dma.c +++ b/arch/arm/mach-bcm2708/dma.c @@ -156,6 +156,8 @@ static void vc_dmaman_init(struct vc_dma dmaman->chan_available = chans_available; dmaman->has_feature[BCM_DMA_FEATURE_FAST_ORD] = 0x0c; /* chans 2 & 3 */ dmaman->has_feature[BCM_DMA_FEATURE_BULK_ORD] = 0x01; /* chan 0 */ + dmaman->has_feature[BCM_DMA_FEATURE_NORMAL_ORD] = 0xfe; /* chans 1 to 7 */ + dmaman->has_feature[BCM_DMA_FEATURE_LITE_ORD] = 0x7f00; /* chans 8 to 14 */ } static int vc_dmaman_chan_alloc(struct vc_dmaman *dmaman, --- a/arch/arm/mach-bcm2708/include/mach/dma.h +++ b/arch/arm/mach-bcm2708/include/mach/dma.h @@ -77,9 +77,13 @@ extern int /*rc*/ bcm_dma_abort(void __i those with higher priority smaller ordinal numbers */ #define BCM_DMA_FEATURE_FAST_ORD 0 #define BCM_DMA_FEATURE_BULK_ORD 1 +#define BCM_DMA_FEATURE_NORMAL_ORD 2 +#define BCM_DMA_FEATURE_LITE_ORD 3 #define BCM_DMA_FEATURE_FAST (1< + * Gellert Weisz + * Copyright 2013-2014 + * + * Based on + * OMAP DMAengine support by Russell King + * + * BCM2708 DMA Driver + * Copyright (C) 2010 Broadcom + * + * Raspberry Pi PCM I2S ALSA Driver + * Copyright (c) by Phil Poole 2013 + * + * MARVELL MMP Peripheral DMA Driver + * Copyright 2012 Marvell International Ltd. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef CONFIG_OF + +/* dma manager */ +#include + +//#define DMA_COMPLETE DMA_SUCCESS + +#endif + +#include +#include + +#include "virt-dma.h" + + +struct bcm2835_dmadev { + struct dma_device ddev; + spinlock_t lock; + void __iomem *base; + struct device_dma_parameters dma_parms; +}; + +struct bcm2835_dma_cb { + uint32_t info; + uint32_t src; + uint32_t dst; + uint32_t length; + uint32_t stride; + uint32_t next; + uint32_t pad[2]; +}; + +struct bcm2835_chan { + struct virt_dma_chan vc; + struct list_head node; + + struct dma_slave_config cfg; + bool cyclic; + + int ch; + struct bcm2835_desc *desc; + + void __iomem *chan_base; + int irq_number; + + unsigned int dreq; +}; + +struct bcm2835_desc { + struct virt_dma_desc vd; + enum dma_transfer_direction dir; + + unsigned int control_block_size; + struct bcm2835_dma_cb *control_block_base; + dma_addr_t control_block_base_phys; + + unsigned int frames; + size_t size; +}; + +#define BCM2835_DMA_CS 0x00 +#define BCM2835_DMA_ADDR 0x04 +#define BCM2835_DMA_SOURCE_AD 0x0c +#define BCM2835_DMA_DEST_AD 0x10 +#define BCM2835_DMA_NEXTCB 0x1C + +/* DMA CS Control and Status bits */ +#define BCM2835_DMA_ACTIVE BIT(0) +#define BCM2835_DMA_INT BIT(2) +#define BCM2835_DMA_ISPAUSED BIT(4) /* Pause requested or not active */ +#define BCM2835_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */ +#define BCM2835_DMA_ERR BIT(8) +#define BCM2835_DMA_ABORT BIT(30) /* Stop current CB, go to next, WO */ +#define BCM2835_DMA_RESET BIT(31) /* WO, self clearing */ + +#define BCM2835_DMA_INT_EN BIT(0) +#define BCM2835_DMA_WAIT_RESP BIT(3) +#define BCM2835_DMA_D_INC BIT(4) +#define BCM2835_DMA_D_WIDTH BIT(5) +#define BCM2835_DMA_D_DREQ BIT(6) +#define BCM2835_DMA_S_INC BIT(8) +#define BCM2835_DMA_S_WIDTH BIT(9) +#define BCM2835_DMA_S_DREQ BIT(10) + +#define BCM2835_DMA_PER_MAP(x) ((x) << 16) +#define BCM2835_DMA_WAITS(x) (((x)&0x1f) << 21) + +#define SDHCI_BCM_DMA_WAITS 0 /* delays slowing DMA transfers: 0-31 */ + +#define BCM2835_DMA_DATA_TYPE_S8 1 +#define BCM2835_DMA_DATA_TYPE_S16 2 +#define BCM2835_DMA_DATA_TYPE_S32 4 +#define BCM2835_DMA_DATA_TYPE_S128 16 + +#define BCM2835_DMA_BULK_MASK BIT(0) +#define BCM2835_DMA_FIQ_MASK (BIT(2) | BIT(3)) + + +/* Valid only for channels 0 - 14, 15 has its own base address */ +#define BCM2835_DMA_CHAN(n) ((n) << 8) /* Base address */ +#define BCM2835_DMA_CHANIO(base, n) ((base) + BCM2835_DMA_CHAN(n)) + +#define MAX_LITE_TRANSFER 32768 +#define MAX_NORMAL_TRANSFER 1073741824 + +static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d) +{ + return container_of(d, struct bcm2835_dmadev, ddev); +} + +static inline struct bcm2835_chan *to_bcm2835_dma_chan(struct dma_chan *c) +{ + return container_of(c, struct bcm2835_chan, vc.chan); +} + +static inline struct bcm2835_desc *to_bcm2835_dma_desc( + struct dma_async_tx_descriptor *t) +{ + return container_of(t, struct bcm2835_desc, vd.tx); +} + +static void dma_dumpregs(struct bcm2835_chan *c) +{ + pr_debug("-------------DMA DUMPREGS-------------\n"); + pr_debug("CS= %u\n", + readl(c->chan_base + BCM2835_DMA_CS)); + pr_debug("ADDR= %u\n", + readl(c->chan_base + BCM2835_DMA_ADDR)); + pr_debug("SOURCE_ADDR= %u\n", + readl(c->chan_base + BCM2835_DMA_SOURCE_AD)); + pr_debug("DEST_AD= %u\n", + readl(c->chan_base + BCM2835_DMA_DEST_AD)); + pr_debug("NEXTCB= %u\n", + readl(c->chan_base + BCM2835_DMA_NEXTCB)); + pr_debug("--------------------------------------\n"); +} + +static void bcm2835_dma_desc_free(struct virt_dma_desc *vd) +{ + struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd); + dma_free_coherent(desc->vd.tx.chan->device->dev, + desc->control_block_size, + desc->control_block_base, + desc->control_block_base_phys); + kfree(desc); +} + +static int bcm2835_dma_abort(void __iomem *chan_base) +{ + unsigned long cs; + long int timeout = 10000; + + cs = readl(chan_base + BCM2835_DMA_CS); + if (!(cs & BCM2835_DMA_ACTIVE)) + return 0; + + /* Write 0 to the active bit - Pause the DMA */ + writel(0, chan_base + BCM2835_DMA_CS); + + /* Wait for any current AXI transfer to complete */ + while ((cs & BCM2835_DMA_ISPAUSED) && --timeout) { + cpu_relax(); + cs = readl(chan_base + BCM2835_DMA_CS); + } + + /* We'll un-pause when we set of our next DMA */ + if (!timeout) + return -ETIMEDOUT; + + if (!(cs & BCM2835_DMA_ACTIVE)) + return 0; + + /* Terminate the control block chain */ + writel(0, chan_base + BCM2835_DMA_NEXTCB); + + /* Abort the whole DMA */ + writel(BCM2835_DMA_ABORT | BCM2835_DMA_ACTIVE, + chan_base + BCM2835_DMA_CS); + + return 0; +} + + +static void bcm2835_dma_start_desc(struct bcm2835_chan *c) +{ + struct virt_dma_desc *vd = vchan_next_desc(&c->vc); + struct bcm2835_desc *d; + + if (!vd) { + c->desc = NULL; + return; + } + + list_del(&vd->node); + + c->desc = d = to_bcm2835_dma_desc(&vd->tx); + + writel(d->control_block_base_phys, c->chan_base + BCM2835_DMA_ADDR); + writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); + +} + +static irqreturn_t bcm2835_dma_callback(int irq, void *data) +{ + struct bcm2835_chan *c = data; + struct bcm2835_desc *d; + unsigned long flags; + + spin_lock_irqsave(&c->vc.lock, flags); + + /* Acknowledge interrupt */ + writel(BCM2835_DMA_INT, c->chan_base + BCM2835_DMA_CS); + + d = c->desc; + + if (d) { + if (c->cyclic) { + vchan_cyclic_callback(&d->vd); + + /* Keep the DMA engine running */ + writel(BCM2835_DMA_ACTIVE, + c->chan_base + BCM2835_DMA_CS); + + } else { + vchan_cookie_complete(&c->desc->vd); + bcm2835_dma_start_desc(c); + } + } + + spin_unlock_irqrestore(&c->vc.lock, flags); + + return IRQ_HANDLED; +} + +static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + int ret; + + dev_dbg(c->vc.chan.device->dev, + "Allocating DMA channel %d\n", c->ch); + + ret = request_irq(c->irq_number, + bcm2835_dma_callback, 0, "DMA IRQ", c); + + return ret; +} + +static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + + vchan_free_chan_resources(&c->vc); + free_irq(c->irq_number, c); + + dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch); +} + +static size_t bcm2835_dma_desc_size(struct bcm2835_desc *d) +{ + return d->size; +} + +static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr) +{ + unsigned int i; + size_t size; + + for (size = i = 0; i < d->frames; i++) { + struct bcm2835_dma_cb *control_block = + &d->control_block_base[i]; + size_t this_size = control_block->length; + dma_addr_t dma; + + if (d->dir == DMA_DEV_TO_MEM) + dma = control_block->dst; + else + dma = control_block->src; + + if (size) + size += this_size; + else if (addr >= dma && addr < dma + this_size) + size += dma + this_size - addr; + } + + return size; +} + +static enum dma_status bcm2835_dma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *txstate) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + struct bcm2835_desc *d; + struct virt_dma_desc *vd; + enum dma_status ret; + unsigned long flags; + dma_addr_t pos; + + ret = dma_cookie_status(chan, cookie, txstate); + if (ret == DMA_COMPLETE || !txstate) + return ret; + + spin_lock_irqsave(&c->vc.lock, flags); + vd = vchan_find_desc(&c->vc, cookie); + if (vd) { + txstate->residue = + bcm2835_dma_desc_size(to_bcm2835_dma_desc(&vd->tx)); + } else if (c->desc && c->desc->vd.tx.cookie == cookie) { + d = c->desc; + + if (d->dir == DMA_MEM_TO_DEV) + pos = readl(c->chan_base + BCM2835_DMA_SOURCE_AD); + else if (d->dir == DMA_DEV_TO_MEM) + pos = readl(c->chan_base + BCM2835_DMA_DEST_AD); + else + pos = 0; + + txstate->residue = bcm2835_dma_desc_size_pos(d, pos); + } else { + txstate->residue = 0; + } + + spin_unlock_irqrestore(&c->vc.lock, flags); + + return ret; +} + +static void bcm2835_dma_issue_pending(struct dma_chan *chan) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&c->vc.lock, flags); + if (vchan_issue_pending(&c->vc) && !c->desc) + bcm2835_dma_start_desc(c); + + spin_unlock_irqrestore(&c->vc.lock, flags); +} + +static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + enum dma_slave_buswidth dev_width; + struct bcm2835_desc *d; + dma_addr_t dev_addr; + unsigned int es, sync_type; + unsigned int frame, max_size; + + /* Grab configuration */ + if (!is_slave_direction(direction)) { + dev_err(chan->device->dev, "%s: bad direction?\n", __func__); + return NULL; + } + + if (direction == DMA_DEV_TO_MEM) { + dev_addr = c->cfg.src_addr; + dev_width = c->cfg.src_addr_width; + sync_type = BCM2835_DMA_S_DREQ; + } else { + dev_addr = c->cfg.dst_addr; + dev_width = c->cfg.dst_addr_width; + sync_type = BCM2835_DMA_D_DREQ; + } + + /* Bus width translates to the element size (ES) */ + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = BCM2835_DMA_DATA_TYPE_S32; + break; + default: + return NULL; + } + + /* Now allocate and setup the descriptor. */ + d = kzalloc(sizeof(*d), GFP_NOWAIT); + if (!d) + return NULL; + + d->dir = direction; + + if (c->ch >= 8) /* we have a LITE channel */ + max_size = MAX_LITE_TRANSFER; + else + max_size = MAX_NORMAL_TRANSFER; + period_len = min(period_len, max_size); + + d->frames = (buf_len-1) / period_len + 1; + + /* Allocate memory for control blocks */ + d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb); + d->control_block_base = dma_zalloc_coherent(chan->device->dev, + d->control_block_size, &d->control_block_base_phys, + GFP_NOWAIT); + + if (!d->control_block_base) { + kfree(d); + return NULL; + } + + /* + * Iterate over all frames, create a control block + * for each frame and link them together. + */ + for (frame = 0; frame < d->frames; frame++) { + struct bcm2835_dma_cb *control_block = + &d->control_block_base[frame]; + + /* Setup adresses */ + if (d->dir == DMA_DEV_TO_MEM) { + control_block->info = BCM2835_DMA_D_INC; + control_block->src = dev_addr; + control_block->dst = buf_addr + frame * period_len; + } else { + control_block->info = BCM2835_DMA_S_INC; + control_block->src = buf_addr + frame * period_len; + control_block->dst = dev_addr; + } + + /* Enable interrupt */ + control_block->info |= BCM2835_DMA_INT_EN; + + /* Setup synchronization */ + if (sync_type != 0) + control_block->info |= sync_type; + + /* Setup DREQ channel */ + if (c->cfg.slave_id != 0) + control_block->info |= + BCM2835_DMA_PER_MAP(c->cfg.slave_id); + + /* Length of a frame */ + if (frame != d->frames-1) + control_block->length = period_len; + else + control_block->length = buf_len - (d->frames - 1) * period_len; + + d->size += control_block->length; + + /* + * Next block is the next frame. + * This function is called on cyclic DMA transfers. + * Therefore, wrap around at number of frames. + */ + control_block->next = d->control_block_base_phys + + sizeof(struct bcm2835_dma_cb) + * ((frame + 1) % d->frames); + } + + c->cyclic = true; + + return vchan_tx_prep(&c->vc, &d->vd, flags); +} + + +static struct dma_async_tx_descriptor *bcm2835_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 bcm2835_chan *c = to_bcm2835_dma_chan(chan); + enum dma_slave_buswidth dev_width; + struct bcm2835_desc *d; + dma_addr_t dev_addr; + struct scatterlist *sgent; + unsigned int es, sync_type; + unsigned int i, j, splitct, max_size; + + if (!is_slave_direction(direction)) { + dev_err(chan->device->dev, "%s: bad direction?\n", __func__); + return NULL; + } + + if (direction == DMA_DEV_TO_MEM) { + dev_addr = c->cfg.src_addr; + dev_width = c->cfg.src_addr_width; + sync_type = BCM2835_DMA_S_DREQ; + } else { + dev_addr = c->cfg.dst_addr; + dev_width = c->cfg.dst_addr_width; + sync_type = BCM2835_DMA_D_DREQ; + } + + /* Bus width translates to the element size (ES) */ + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = BCM2835_DMA_DATA_TYPE_S32; + break; + default: + return NULL; + } + + /* Now allocate and setup the descriptor. */ + d = kzalloc(sizeof(*d), GFP_NOWAIT); + if (!d) + return NULL; + + d->dir = direction; + + if (c->ch >= 8) /* we have a LITE channel */ + max_size = MAX_LITE_TRANSFER; + else + max_size = MAX_NORMAL_TRANSFER; + + /* We store the length of the SG list in d->frames + taking care to account for splitting up transfers + too large for a LITE channel */ + + d->frames = 0; + for_each_sg(sgl, sgent, sg_len, i) { + uint32_t len = sg_dma_len(sgent); + d->frames += 1 + len / max_size; + } + + /* Allocate memory for control blocks */ + d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb); + d->control_block_base = dma_zalloc_coherent(chan->device->dev, + d->control_block_size, &d->control_block_base_phys, + GFP_NOWAIT); + + if (!d->control_block_base) { + kfree(d); + return NULL; + } + + /* + * Iterate over all SG entries, create a control block + * for each frame and link them together. + */ + + /* we count the number of times an SG entry had to be splitct + as a result of using a LITE channel */ + splitct = 0; + + for_each_sg(sgl, sgent, sg_len, i) { + dma_addr_t addr = sg_dma_address(sgent); + uint32_t len = sg_dma_len(sgent); + + for (j = 0; j < len; j += max_size) { + struct bcm2835_dma_cb *control_block = + &d->control_block_base[i+splitct]; + + /* Setup adresses */ + if (d->dir == DMA_DEV_TO_MEM) { + control_block->info = BCM2835_DMA_D_INC | + BCM2835_DMA_D_WIDTH | BCM2835_DMA_S_DREQ; + control_block->src = dev_addr; + control_block->dst = addr + (dma_addr_t)j; + } else { + control_block->info = BCM2835_DMA_S_INC | + BCM2835_DMA_S_WIDTH | BCM2835_DMA_D_DREQ; + control_block->src = addr + (dma_addr_t)j; + control_block->dst = dev_addr; + } + + /* Common part */ + control_block->info |= BCM2835_DMA_WAITS(SDHCI_BCM_DMA_WAITS); + control_block->info |= BCM2835_DMA_WAIT_RESP; + + /* Enable */ + if (i == sg_len-1 && len-j <= max_size) + control_block->info |= BCM2835_DMA_INT_EN; + + /* Setup synchronization */ + if (sync_type != 0) + control_block->info |= sync_type; + + /* Setup DREQ channel */ + c->dreq = c->cfg.slave_id; /* DREQ loaded from config */ + + if (c->dreq != 0) + control_block->info |= + BCM2835_DMA_PER_MAP(c->dreq); + + /* Length of a frame */ + control_block->length = min(len-j, max_size); + d->size += control_block->length; + + /* + * Next block is the next frame. + */ + if (i < sg_len-1 || len-j > max_size) { + /* next block is the next frame. */ + control_block->next = d->control_block_base_phys + + sizeof(struct bcm2835_dma_cb) * (i + splitct + 1); + } else { + /* next block is empty. */ + control_block->next = 0; + } + + if (len-j > max_size) + splitct++; + } + } + + c->cyclic = false; + + return vchan_tx_prep(&c->vc, &d->vd, flags); +} + +static int bcm2835_dma_slave_config(struct bcm2835_chan *c, + struct dma_slave_config *cfg) +{ + if ((cfg->direction == DMA_DEV_TO_MEM && + cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || + (cfg->direction == DMA_MEM_TO_DEV && + cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) || + !is_slave_direction(cfg->direction)) { + return -EINVAL; + } + + c->cfg = *cfg; + + return 0; +} + +static int bcm2835_dma_terminate_all(struct bcm2835_chan *c) +{ + struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device); + unsigned long flags; + int timeout = 10000; + LIST_HEAD(head); + + spin_lock_irqsave(&c->vc.lock, flags); + + /* Prevent this channel being scheduled */ + spin_lock(&d->lock); + list_del_init(&c->node); + spin_unlock(&d->lock); + + /* + * Stop DMA activity: we assume the callback will not be called + * after bcm_dma_abort() returns (even if it does, it will see + * c->desc is NULL and exit.) + */ + if (c->desc) { + c->desc = NULL; + bcm2835_dma_abort(c->chan_base); + + /* Wait for stopping */ + while (--timeout) { + if (!(readl(c->chan_base + BCM2835_DMA_CS) & + BCM2835_DMA_ACTIVE)) + break; + + cpu_relax(); + } + + if (!timeout) + dev_err(d->ddev.dev, "DMA transfer could not be terminated\n"); + } + + vchan_get_all_descriptors(&c->vc, &head); + spin_unlock_irqrestore(&c->vc.lock, flags); + vchan_dma_desc_free_list(&c->vc, &head); + + return 0; +} + +static int bcm2835_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, + unsigned long arg) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + + switch (cmd) { + case DMA_SLAVE_CONFIG: + return bcm2835_dma_slave_config(c, + (struct dma_slave_config *)arg); + + case DMA_TERMINATE_ALL: + return bcm2835_dma_terminate_all(c); + + default: + return -ENXIO; + } +} + +#ifdef CONFIG_OF +static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq) +{ + struct bcm2835_chan *c; + + c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + c->vc.desc_free = bcm2835_dma_desc_free; + vchan_init(&c->vc, &d->ddev); + INIT_LIST_HEAD(&c->node); + + d->ddev.chancnt++; + + c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id); + c->ch = chan_id; + c->irq_number = irq; + + return 0; +} +#endif + +static int bcm2708_dma_chan_init(struct bcm2835_dmadev *d, + void __iomem *chan_base, int chan_id, int irq) +{ + struct bcm2835_chan *c; + + c = devm_kzalloc(d->ddev.dev, sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + c->vc.desc_free = bcm2835_dma_desc_free; + vchan_init(&c->vc, &d->ddev); + INIT_LIST_HEAD(&c->node); + + d->ddev.chancnt++; + + c->chan_base = chan_base; + c->ch = chan_id; + c->irq_number = irq; + + return 0; +} + + +static void bcm2835_dma_free(struct bcm2835_dmadev *od) +{ + struct bcm2835_chan *c, *next; + + list_for_each_entry_safe(c, next, &od->ddev.channels, + vc.chan.device_node) { + list_del(&c->vc.chan.device_node); + tasklet_kill(&c->vc.task); + } +} + +static const struct of_device_id bcm2835_dma_of_match[] = { + { .compatible = "brcm,bcm2835-dma", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm2835_dma_of_match); + +#ifdef CONFIG_OF +static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec, + struct of_dma *ofdma) +{ + struct bcm2835_dmadev *d = ofdma->of_dma_data; + struct dma_chan *chan; + + chan = dma_get_any_slave_channel(&d->ddev); + if (!chan) + return NULL; + + /* Set DREQ from param */ + to_bcm2835_dma_chan(chan)->dreq = spec->args[0]; + + return chan; +} +#endif + +static int bcm2835_dma_device_slave_caps(struct dma_chan *dchan, + struct dma_slave_caps *caps) +{ + caps->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + caps->dstn_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + caps->cmd_pause = false; + caps->cmd_terminate = true; + + return 0; +} + +static int bcm2835_dma_probe(struct platform_device *pdev) +{ + struct bcm2835_dmadev *od; +#ifdef CONFIG_OF + struct resource *res; + void __iomem *base; + uint32_t chans_available; +#endif + int rc; + int i; + int irq; + + + if (!pdev->dev.dma_mask) + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; + + /* If CONFIG_OF is selected, device tree is used */ + /* hence the difference between probing */ + +#ifndef CONFIG_OF + + rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32)); + if (rc) + return rc; + dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); + + + od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); + if (!od) + return -ENOMEM; + + pdev->dev.dma_parms = &od->dma_parms; + dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF); + + + dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask); + dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); + od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources; + od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources; + od->ddev.device_tx_status = bcm2835_dma_tx_status; + od->ddev.device_issue_pending = bcm2835_dma_issue_pending; + od->ddev.device_slave_caps = bcm2835_dma_device_slave_caps; + od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; + od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; + od->ddev.device_control = bcm2835_dma_control; + od->ddev.dev = &pdev->dev; + INIT_LIST_HEAD(&od->ddev.channels); + spin_lock_init(&od->lock); + + platform_set_drvdata(pdev, od); + + for (i = 0; i < 5; i++) { + void __iomem *chan_base; + int chan_id; + + chan_id = bcm_dma_chan_alloc(BCM_DMA_FEATURE_LITE, + &chan_base, + &irq); + + if (chan_id < 0) + break; + + rc = bcm2708_dma_chan_init(od, chan_base, chan_id, irq); + if (rc) + goto err_no_dma; + } +#else + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + if (rc) + return rc; + + + od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); + if (!od) + return -ENOMEM; + + pdev->dev.dma_parms = &od->dma_parms; + dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF); + + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + od->base = base; + + + dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask); + dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); + od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources; + od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources; + od->ddev.device_tx_status = bcm2835_dma_tx_status; + od->ddev.device_issue_pending = bcm2835_dma_issue_pending; + od->ddev.device_slave_caps = bcm2835_dma_device_slave_caps; + od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; + od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; + od->ddev.device_control = bcm2835_dma_control; + od->ddev.dev = &pdev->dev; + INIT_LIST_HEAD(&od->ddev.channels); + spin_lock_init(&od->lock); + + platform_set_drvdata(pdev, od); + + + /* Request DMA channel mask from device tree */ + if (of_property_read_u32(pdev->dev.of_node, + "brcm,dma-channel-mask", + &chans_available)) { + dev_err(&pdev->dev, "Failed to get channel mask\n"); + rc = -EINVAL; + goto err_no_dma; + } + + + /* + * Do not use the FIQ and BULK channels, + * because they are used by the GPU. + */ + chans_available &= ~(BCM2835_DMA_FIQ_MASK | BCM2835_DMA_BULK_MASK); + + + for (i = 0; i < pdev->num_resources; i++) { + irq = platform_get_irq(pdev, i); + if (irq < 0) + break; + + if (chans_available & (1 << i)) { + rc = bcm2835_dma_chan_init(od, i, irq); + if (rc) + goto err_no_dma; + } + } + + dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i); + + /* Device-tree DMA controller registration */ + rc = of_dma_controller_register(pdev->dev.of_node, + bcm2835_dma_xlate, od); + if (rc) { + dev_err(&pdev->dev, "Failed to register DMA controller\n"); + goto err_no_dma; + } +#endif + + rc = dma_async_device_register(&od->ddev); + if (rc) { + dev_err(&pdev->dev, + "Failed to register slave DMA engine device: %d\n", rc); + goto err_no_dma; + } + + dev_info(&pdev->dev, "Load BCM2835 DMA engine driver\n"); + + return 0; + +err_no_dma: + bcm2835_dma_free(od); + return rc; +} + +static int bcm2835_dma_remove(struct platform_device *pdev) +{ + struct bcm2835_dmadev *od = platform_get_drvdata(pdev); + + dma_async_device_unregister(&od->ddev); + bcm2835_dma_free(od); + + return 0; +} + +#ifndef CONFIG_OF + + +static struct platform_driver bcm2835_dma_driver = { + .probe = bcm2835_dma_probe, + .remove = bcm2835_dma_remove, + .driver = { + .name = "bcm2708-dmaengine", + .owner = THIS_MODULE, + }, +}; + +static struct platform_device *pdev; + +static const struct platform_device_info bcm2835_dma_dev_info = { + .name = "bcm2708-dmaengine", + .id = -1, +}; + +static int bcm2835_dma_init(void) +{ + int rc = platform_driver_register(&bcm2835_dma_driver); + + if (rc == 0) { + pdev = platform_device_register_full(&bcm2835_dma_dev_info); + if (IS_ERR(pdev)) { + platform_driver_unregister(&bcm2835_dma_driver); + rc = PTR_ERR(pdev); + } + } + + return rc; +} +module_init(bcm2835_dma_init); /* preferable to subsys_initcall */ + +static void __exit bcm2835_dma_exit(void) +{ + platform_device_unregister(pdev); + platform_driver_unregister(&bcm2835_dma_driver); +} +module_exit(bcm2835_dma_exit); + +#else + +static struct platform_driver bcm2835_dma_driver = { + .probe = bcm2835_dma_probe, + .remove = bcm2835_dma_remove, + .driver = { + .name = "bcm2835-dma", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(bcm2835_dma_of_match), + }, +}; + +module_platform_driver(bcm2835_dma_driver); + +#endif + +MODULE_ALIAS("platform:bcm2835-dma"); +MODULE_DESCRIPTION("BCM2835 DMA engine driver"); +MODULE_AUTHOR("Florian Meier "); +MODULE_AUTHOR("Gellert Weisz "); +MODULE_LICENSE("GPL v2");