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openwrt/target/linux/brcm2708/patches-3.18/0029-dmaengine-Add-support-for-BCM2708.patch
John Crispin 408c969626 brcm2708: update to v3.18 
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

SVN-Revision: 44392
2015-02-11 10:17:55 +00:00

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From ce3d899b0ed284a6e901fb6f4a459fdcf003cadb Mon Sep 17 00:00:00 2001
From: Florian Meier <florian.meier@koalo.de>
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 <florian.meier@koalo.de>
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
diff --git a/arch/arm/mach-bcm2708/dma.c b/arch/arm/mach-bcm2708/dma.c
index 1da2413..a5e58d1 100644
--- 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_dmaman *dmaman, void __iomem *dma_base,
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,
diff --git a/arch/arm/mach-bcm2708/include/mach/dma.h b/arch/arm/mach-bcm2708/include/mach/dma.h
index a4aac4c..d03e7b5 100644
--- 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 __iomem *dma_chan_base);
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<<BCM_DMA_FEATURE_FAST_ORD)
#define BCM_DMA_FEATURE_BULK (1<<BCM_DMA_FEATURE_BULK_ORD)
-#define BCM_DMA_FEATURE_COUNT 2
+#define BCM_DMA_FEATURE_NORMAL (1<<BCM_DMA_FEATURE_NORMAL_ORD)
+#define BCM_DMA_FEATURE_LITE (1<<BCM_DMA_FEATURE_LITE_ORD)
+#define BCM_DMA_FEATURE_COUNT 4
/* return channel no or -ve error */
extern int bcm_dma_chan_alloc(unsigned preferred_feature_set,
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index de46982..c9b8eb5 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -330,6 +330,12 @@ config DMA_BCM2835
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
+config DMA_BCM2708
+ tristate "BCM2708 DMA engine support"
+ depends on MACH_BCM2708
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+
config TI_CPPI41
tristate "AM33xx CPPI41 DMA support"
depends on ARCH_OMAP
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index cb626c1..d3c4a82 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
obj-$(CONFIG_DMA_OMAP) += omap-dma.o
obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
+obj-$(CONFIG_DMA_BCM2708) += bcm2708-dmaengine.o
obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
obj-$(CONFIG_TI_CPPI41) += cppi41.o
diff --git a/drivers/dma/bcm2708-dmaengine.c b/drivers/dma/bcm2708-dmaengine.c
new file mode 100644
index 0000000..10463db
--- /dev/null
+++ b/drivers/dma/bcm2708-dmaengine.c
@@ -0,0 +1,1052 @@
+/*
+ * BCM2835 DMA engine support
+ *
+ * This driver supports cyclic and scatter/gather DMA transfers.
+ *
+ * Author: Florian Meier <florian.meier@koalo.de>
+ * Gellert Weisz <gellert@raspberrypi.org>
+ * 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 <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+#ifndef CONFIG_OF
+
+/* dma manager */
+#include <mach/dma.h>
+
+//#define DMA_COMPLETE DMA_SUCCESS
+
+#endif
+
+#include <linux/of.h>
+#include <linux/of_dma.h>
+
+#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 <florian.meier@koalo.de>");
+MODULE_AUTHOR("Gellert Weisz <gellert@raspberrypi.org>");
+MODULE_LICENSE("GPL v2");
--
1.8.3.2
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