From 04a4ceef489437512b4d40071e049950d56fbb27 Mon Sep 17 00:00:00 2001 From: Florian Meier Date: Fri, 22 Nov 2013 14:22:53 +0100 Subject: [PATCH 007/171] dmaengine: Add support for BCM2708 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 dmaengine: bcm2708: Remove chancnt affectations Mirror bcm2835-dma.c commit 9eba5536a7434c69d8c185d4bd1c70734d92287d: chancnt is already filled by dma_async_device_register, which uses the channel list to know how much channels there is. Since it's already filled, we can safely remove it from the drivers' probe function. Signed-off-by: Noralf Trønnes dmaengine: bcm2708: overwrite dreq only if it is not set dreq is set when the DMA channel is fetched from Device Tree. slave_id is set using dmaengine_slave_config(). Only overwrite dreq with slave_id if it is not set. dreq/slave_id in the cyclic DMA case is not touched, because I don't have hardware to test with. Signed-off-by: Noralf Trønnes dmaengine: bcm2708: do device registration in the board file Don't register the device in the driver. Do it in the board file. Signed-off-by: Noralf Trønnes dmaengine: bcm2708: don't restrict DT support to ARCH_BCM2835 Both ARCH_BCM2835 and ARCH_BCM270x are built with OF now. Add Device Tree support to the non ARCH_BCM2835 case. Use the same driver name regardless of architecture. Signed-off-by: Noralf Trønnes BCM270x_DT: add bcm2835-dma entry Add Device Tree entry for bcm2835-dma. The entry doesn't contain any resources since they are handled by the arch/arm/mach-bcm270x/dma.c driver. In non-DT mode, don't add the device in the board file. Signed-off-by: Noralf Trønnes bcm2708-dmaengine: Add debug options BCM270x: Add memory and irq resources to dmaengine device and DT Prepare for merging of the legacy DMA API arch driver dma.c with bcm2708-dmaengine by adding memory and irq resources both to platform file device and Device Tree node. Don't use BCM_DMAMAN_DRIVER_NAME so we don't have to include mach/dma.h Signed-off-by: Noralf Trønnes dmaengine: bcm2708: Merge with arch dma.c driver and disable dma.c Merge the legacy DMA API driver with bcm2708-dmaengine. This is done so we can use bcm2708_fb on ARCH_BCM2835 (mailbox driver is also needed). Changes to the dma.c code: - Use BIT() macro. - Cutdown some comments to one line. - Add mutex to vc_dmaman and use this, since the dev lock is locked during probing of the engine part. - Add global g_dmaman variable since drvdata is used by the engine part. - Restructure for readability: vc_dmaman_chan_alloc() vc_dmaman_chan_free() bcm_dma_chan_free() - Restructure bcm_dma_chan_alloc() to simplify error handling. - Use device irq resources instead of hardcoded bcm_dma_irqs table. - Remove dev_dmaman_register() and code it directly. - Remove dev_dmaman_deregister() and code it directly. - Simplify bcm_dmaman_probe() using devm_* functions. - Get dmachans from DT if available. - Keep 'dma.dmachans' module argument name for backwards compatibility. Make it available on ARCH_BCM2835 as well. Signed-off-by: Noralf Trønnes dmaengine: bcm2708: set residue_granularity field bcm2708-dmaengine supports residue reporting at burst level but didn't report this via the residue_granularity field. Without this field set properly we get playback issues with I2S cards. --- arch/arm/mach-bcm2708/bcm2708.c | 68 ++ arch/arm/mach-bcm2709/bcm2709.c | 68 ++ drivers/dma/Kconfig | 13 +- drivers/dma/Makefile | 1 + drivers/dma/bcm2708-dmaengine.c | 1298 +++++++++++++++++++++++++++++ include/linux/platform_data/dma-bcm2708.h | 127 +++ 6 files changed, 1574 insertions(+), 1 deletion(-) create mode 100644 drivers/dma/bcm2708-dmaengine.c create mode 100644 include/linux/platform_data/dma-bcm2708.h --- a/arch/arm/mach-bcm2708/bcm2708.c +++ b/arch/arm/mach-bcm2708/bcm2708.c @@ -234,6 +234,73 @@ static struct amba_device *amba_devs[] _ &uart0_device, }; +static struct resource bcm2708_dmaengine_resources[] = { + { + .start = DMA_BASE, + .end = DMA_BASE + SZ_4K - 1, + .flags = IORESOURCE_MEM, + }, { + .start = IRQ_DMA0, + .end = IRQ_DMA0, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA1, + .end = IRQ_DMA1, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA2, + .end = IRQ_DMA2, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA3, + .end = IRQ_DMA3, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA4, + .end = IRQ_DMA4, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA5, + .end = IRQ_DMA5, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA6, + .end = IRQ_DMA6, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA7, + .end = IRQ_DMA7, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA8, + .end = IRQ_DMA8, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA9, + .end = IRQ_DMA9, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA10, + .end = IRQ_DMA10, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA11, + .end = IRQ_DMA11, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA12, + .end = IRQ_DMA12, + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device bcm2708_dmaengine_device = { + .name = "bcm2708-dmaengine", + .id = -1, + .resource = bcm2708_dmaengine_resources, + .num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources), +}; + static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON); static struct platform_device bcm2708_fb_device = { @@ -463,6 +530,7 @@ void __init bcm2708_init(void) bcm2708_init_clocks(); bcm2708_dt_init(); + bcm_register_device_dt(&bcm2708_dmaengine_device); bcm_register_device(&bcm2708_vcio_device); #ifdef CONFIG_BCM2708_GPIO bcm_register_device_dt(&bcm2708_gpio_device); --- a/arch/arm/mach-bcm2709/bcm2709.c +++ b/arch/arm/mach-bcm2709/bcm2709.c @@ -244,6 +244,73 @@ static struct amba_device *amba_devs[] _ &uart0_device, }; +static struct resource bcm2708_dmaengine_resources[] = { + { + .start = DMA_BASE, + .end = DMA_BASE + SZ_4K - 1, + .flags = IORESOURCE_MEM, + }, { + .start = IRQ_DMA0, + .end = IRQ_DMA0, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA1, + .end = IRQ_DMA1, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA2, + .end = IRQ_DMA2, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA3, + .end = IRQ_DMA3, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA4, + .end = IRQ_DMA4, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA5, + .end = IRQ_DMA5, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA6, + .end = IRQ_DMA6, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA7, + .end = IRQ_DMA7, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA8, + .end = IRQ_DMA8, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA9, + .end = IRQ_DMA9, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA10, + .end = IRQ_DMA10, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA11, + .end = IRQ_DMA11, + .flags = IORESOURCE_IRQ, + }, { + .start = IRQ_DMA12, + .end = IRQ_DMA12, + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device bcm2708_dmaengine_device = { + .name = "bcm2708-dmaengine", + .id = -1, + .resource = bcm2708_dmaengine_resources, + .num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources), +}; + static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON); static struct platform_device bcm2708_fb_device = { @@ -483,6 +550,7 @@ void __init bcm2709_init(void) bcm2709_init_clocks(); bcm2709_dt_init(); + bcm_register_device_dt(&bcm2708_dmaengine_device); bcm_register_device(&bcm2708_vcio_device); #ifdef CONFIG_BCM2708_GPIO bcm_register_device_dt(&bcm2708_gpio_device); --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -337,6 +337,17 @@ config DMA_BCM2835 select DMA_ENGINE select DMA_VIRTUAL_CHANNELS +config DMA_BCM2708 + tristate "BCM2708 DMA engine support" + depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835 + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + +config DMA_BCM2708_LEGACY + bool "BCM2708 DMA legacy API support" + depends on DMA_BCM2708 + default y + config TI_CPPI41 tristate "AM33xx CPPI41 DMA support" depends on ARCH_OMAP @@ -385,7 +396,7 @@ config MOXART_DMA select DMA_VIRTUAL_CHANNELS help Enable support for the MOXA ART SoC DMA controller. - + config FSL_EDMA tristate "Freescale eDMA engine support" depends on OF --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -39,6 +39,7 @@ 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_DMA_JZ4780) += dma-jz4780.o --- /dev/null +++ b/drivers/dma/bcm2708-dmaengine.c @@ -0,0 +1,1298 @@ +/* + * BCM2835 DMA engine support + * + * This driver supports cyclic and scatter/gather DMA transfers. + * + * Author: Florian Meier + * 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 +#include +#include +#include + +#include "virt-dma.h" + +static unsigned dma_debug; + +/* + * Legacy DMA API + */ + +#ifdef CONFIG_DMA_BCM2708_LEGACY + +#define CACHE_LINE_MASK 31 +#define DEFAULT_DMACHAN_BITMAP 0x10 /* channel 4 only */ + +/* valid only for channels 0 - 14, 15 has its own base address */ +#define BCM2708_DMA_CHAN(n) ((n) << 8) /* base address */ +#define BCM2708_DMA_CHANIO(dma_base, n) \ + ((void __iomem *)((char *)(dma_base) + BCM2708_DMA_CHAN(n))) + +struct vc_dmaman { + void __iomem *dma_base; + u32 chan_available; /* bitmap of available channels */ + u32 has_feature[BCM_DMA_FEATURE_COUNT]; /* bitmap of feature presence */ + struct mutex lock; +}; + +static struct device *dmaman_dev; /* we assume there's only one! */ +static struct vc_dmaman *g_dmaman; /* DMA manager */ +static int dmachans = -1; /* module parameter */ + +/* DMA Auxiliary Functions */ + +/* A DMA buffer on an arbitrary boundary may separate a cache line into a + section inside the DMA buffer and another section outside it. + Even if we flush DMA buffers from the cache there is always the chance that + during a DMA someone will access the part of a cache line that is outside + the DMA buffer - which will then bring in unwelcome data. + Without being able to dictate our own buffer pools we must insist that + DMA buffers consist of a whole number of cache lines. +*/ +extern int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len) +{ + int i; + + for (i = 0; i < sg_len; i++) { + if (sg_ptr[i].offset & CACHE_LINE_MASK || + sg_ptr[i].length & CACHE_LINE_MASK) + return 0; + } + + return 1; +} +EXPORT_SYMBOL_GPL(bcm_sg_suitable_for_dma); + +extern void bcm_dma_start(void __iomem *dma_chan_base, + dma_addr_t control_block) +{ + dsb(); /* ARM data synchronization (push) operation */ + + writel(control_block, dma_chan_base + BCM2708_DMA_ADDR); + writel(BCM2708_DMA_ACTIVE, dma_chan_base + BCM2708_DMA_CS); +} +EXPORT_SYMBOL_GPL(bcm_dma_start); + +extern void bcm_dma_wait_idle(void __iomem *dma_chan_base) +{ + dsb(); + + /* ugly busy wait only option for now */ + while (readl(dma_chan_base + BCM2708_DMA_CS) & BCM2708_DMA_ACTIVE) + cpu_relax(); +} +EXPORT_SYMBOL_GPL(bcm_dma_wait_idle); + +extern bool bcm_dma_is_busy(void __iomem *dma_chan_base) +{ + dsb(); + + return readl(dma_chan_base + BCM2708_DMA_CS) & BCM2708_DMA_ACTIVE; +} +EXPORT_SYMBOL_GPL(bcm_dma_is_busy); + +/* Complete an ongoing DMA (assuming its results are to be ignored) + Does nothing if there is no DMA in progress. + This routine waits for the current AXI transfer to complete before + terminating the current DMA. If the current transfer is hung on a DREQ used + by an uncooperative peripheral the AXI transfer may never complete. In this + case the routine times out and return a non-zero error code. + Use of this routine doesn't guarantee that the ongoing or aborted DMA + does not produce an interrupt. +*/ +extern int bcm_dma_abort(void __iomem *dma_chan_base) +{ + unsigned long int cs; + int rc = 0; + + cs = readl(dma_chan_base + BCM2708_DMA_CS); + + if (BCM2708_DMA_ACTIVE & cs) { + long int timeout = 10000; + + /* write 0 to the active bit - pause the DMA */ + writel(0, dma_chan_base + BCM2708_DMA_CS); + + /* wait for any current AXI transfer to complete */ + while (0 != (cs & BCM2708_DMA_ISPAUSED) && --timeout >= 0) + cs = readl(dma_chan_base + BCM2708_DMA_CS); + + if (0 != (cs & BCM2708_DMA_ISPAUSED)) { + /* we'll un-pause when we set of our next DMA */ + rc = -ETIMEDOUT; + + } else if (BCM2708_DMA_ACTIVE & cs) { + /* terminate the control block chain */ + writel(0, dma_chan_base + BCM2708_DMA_NEXTCB); + + /* abort the whole DMA */ + writel(BCM2708_DMA_ABORT | BCM2708_DMA_ACTIVE, + dma_chan_base + BCM2708_DMA_CS); + } + } + + return rc; +} +EXPORT_SYMBOL_GPL(bcm_dma_abort); + + /* DMA Manager Device Methods */ + +static void vc_dmaman_init(struct vc_dmaman *dmaman, void __iomem *dma_base, + u32 chans_available) +{ + dmaman->dma_base = dma_base; + dmaman->chan_available = chans_available; + dmaman->has_feature[BCM_DMA_FEATURE_FAST_ORD] = 0x0c; /* 2 & 3 */ + dmaman->has_feature[BCM_DMA_FEATURE_BULK_ORD] = 0x01; /* 0 */ + dmaman->has_feature[BCM_DMA_FEATURE_NORMAL_ORD] = 0xfe; /* 1 to 7 */ + dmaman->has_feature[BCM_DMA_FEATURE_LITE_ORD] = 0x7f00; /* 8 to 14 */ +} + +static int vc_dmaman_chan_alloc(struct vc_dmaman *dmaman, + unsigned preferred_feature_set) +{ + u32 chans; + int chan = 0; + int feature; + + chans = dmaman->chan_available; + for (feature = 0; feature < BCM_DMA_FEATURE_COUNT; feature++) + /* select the subset of available channels with the desired + feature so long as some of the candidate channels have that + feature */ + if ((preferred_feature_set & (1 << feature)) && + (chans & dmaman->has_feature[feature])) + chans &= dmaman->has_feature[feature]; + + if (!chans) + return -ENOENT; + + /* return the ordinal of the first channel in the bitmap */ + while (chans != 0 && (chans & 1) == 0) { + chans >>= 1; + chan++; + } + /* claim the channel */ + dmaman->chan_available &= ~(1 << chan); + + return chan; +} + +static int vc_dmaman_chan_free(struct vc_dmaman *dmaman, int chan) +{ + if (chan < 0) + return -EINVAL; + + if ((1 << chan) & dmaman->chan_available) + return -EIDRM; + + dmaman->chan_available |= (1 << chan); + + return 0; +} + +/* DMA Manager Monitor */ + +extern int bcm_dma_chan_alloc(unsigned preferred_feature_set, + void __iomem **out_dma_base, int *out_dma_irq) +{ + struct vc_dmaman *dmaman = g_dmaman; + struct platform_device *pdev = to_platform_device(dmaman_dev); + struct resource *r; + int chan; + + if (!dmaman_dev) + return -ENODEV; + + mutex_lock(&dmaman->lock); + chan = vc_dmaman_chan_alloc(dmaman, preferred_feature_set); + if (chan < 0) + goto out; + + r = platform_get_resource(pdev, IORESOURCE_IRQ, (unsigned int)chan); + if (!r) { + dev_err(dmaman_dev, "failed to get irq for DMA channel %d\n", + chan); + vc_dmaman_chan_free(dmaman, chan); + chan = -ENOENT; + goto out; + } + + *out_dma_base = BCM2708_DMA_CHANIO(dmaman->dma_base, chan); + *out_dma_irq = r->start; + dev_dbg(dmaman_dev, + "Legacy API allocated channel=%d, base=%p, irq=%i\n", + chan, *out_dma_base, *out_dma_irq); + +out: + mutex_unlock(&dmaman->lock); + + return chan; +} +EXPORT_SYMBOL_GPL(bcm_dma_chan_alloc); + +extern int bcm_dma_chan_free(int channel) +{ + struct vc_dmaman *dmaman = g_dmaman; + int rc; + + if (!dmaman_dev) + return -ENODEV; + + mutex_lock(&dmaman->lock); + rc = vc_dmaman_chan_free(dmaman, channel); + mutex_unlock(&dmaman->lock); + + return rc; +} +EXPORT_SYMBOL_GPL(bcm_dma_chan_free); + +static int bcm_dmaman_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct vc_dmaman *dmaman; + struct resource *r; + void __iomem *dma_base; + uint32_t val; + + if (!of_property_read_u32(dev->of_node, + "brcm,dma-channel-mask", &val)) + dmachans = val; + else if (dmachans == -1) + dmachans = DEFAULT_DMACHAN_BITMAP; + + dmaman = devm_kzalloc(dev, sizeof(*dmaman), GFP_KERNEL); + if (!dmaman) + return -ENOMEM; + + mutex_init(&dmaman->lock); + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dma_base = devm_ioremap_resource(dev, r); + if (IS_ERR(dma_base)) + return PTR_ERR(dma_base); + + vc_dmaman_init(dmaman, dma_base, dmachans); + g_dmaman = dmaman; + dmaman_dev = dev; + + dev_info(dev, "DMA legacy API manager at %p, dmachans=0x%x\n", + dma_base, dmachans); + + return 0; +} + +static int bcm_dmaman_remove(struct platform_device *pdev) +{ + dmaman_dev = NULL; + + return 0; +} + +#else /* CONFIG_DMA_BCM2708_LEGACY */ + +static int bcm_dmaman_remove(struct platform_device *pdev) +{ + return 0; +} + +#endif /* CONFIG_DMA_BCM2708_LEGACY */ + +/* + * DMA engine + */ + +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 */ + u32 waits = SDHCI_BCM_DMA_WAITS; + if ((dma_debug >> 0) & 0x1f) + waits = (dma_debug >> 0) & 0x1f; + control_block->info |= BCM2835_DMA_WAITS(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 */ + 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 dma_chan *chan, + struct dma_slave_config *cfg) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + 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; + if (!c->dreq) + c->dreq = cfg->slave_id; + + return 0; +} + +static int bcm2835_dma_terminate_all(struct dma_chan *chan) +{ + struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + 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; +} + +#ifndef CONFIG_DMA_BCM2708_LEGACY +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); + + 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); + + 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); + +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; +} + +static int bcm2835_dma_probe(struct platform_device *pdev) +{ + struct bcm2835_dmadev *od; +#ifndef CONFIG_DMA_BCM2708_LEGACY + 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; + +#ifdef CONFIG_DMA_BCM2708_LEGACY + + 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; + + rc = bcm_dmaman_probe(pdev); + if (rc) + return rc; + + 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_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; + od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; + od->ddev.device_terminate_all = bcm2835_dma_terminate_all; + od->ddev.device_config = bcm2835_dma_slave_config; + od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + 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; + } + + if (pdev->dev.of_node) { + 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; + } + } + +#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_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; + od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; + od->ddev.device_terminate_all = bcm2835_dma_terminate_all; + od->ddev.device_config = bcm2835_dma_slave_config; + od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + 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"); + dev_info(&pdev->dev, "dma_debug:%x\n", dma_debug); + + 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); + bcm_dmaman_remove(pdev); + + return 0; +} + +static struct platform_driver bcm2835_dma_driver = { + .probe = bcm2835_dma_probe, + .remove = bcm2835_dma_remove, + .driver = { + .name = "bcm2708-dmaengine", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(bcm2835_dma_of_match), + }, +}; + +static int bcm2835_init(void) +{ + return platform_driver_register(&bcm2835_dma_driver); +} + +static void bcm2835_exit(void) +{ + platform_driver_unregister(&bcm2835_dma_driver); +} + +/* + * Load after serial driver (arch_initcall) so we see the messages if it fails, + * but before drivers (module_init) that need a DMA channel. + */ +subsys_initcall(bcm2835_init); +module_exit(bcm2835_exit); + +module_param(dma_debug, uint, 0644); +#ifdef CONFIG_DMA_BCM2708_LEGACY +/* Keep backward compatibility: dma.dmachans= */ +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "dma." +module_param(dmachans, int, 0644); +#endif +MODULE_ALIAS("platform:bcm2835-dma"); +MODULE_DESCRIPTION("BCM2835 DMA engine driver"); +MODULE_AUTHOR("Florian Meier "); +MODULE_AUTHOR("Gellert Weisz "); +MODULE_LICENSE("GPL v2"); --- /dev/null +++ b/include/linux/platform_data/dma-bcm2708.h @@ -0,0 +1,127 @@ +/* + * Copyright (C) 2010 Broadcom + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _PLAT_BCM2708_DMA_H +#define _PLAT_BCM2708_DMA_H + +/* DMA CS Control and Status bits */ +#define BCM2708_DMA_ACTIVE BIT(0) +#define BCM2708_DMA_INT BIT(2) +#define BCM2708_DMA_ISPAUSED BIT(4) /* Pause requested or not active */ +#define BCM2708_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */ +#define BCM2708_DMA_ERR BIT(8) +#define BCM2708_DMA_ABORT BIT(30) /* stop current CB, go to next, WO */ +#define BCM2708_DMA_RESET BIT(31) /* WO, self clearing */ + +/* DMA control block "info" field bits */ +#define BCM2708_DMA_INT_EN BIT(0) +#define BCM2708_DMA_TDMODE BIT(1) +#define BCM2708_DMA_WAIT_RESP BIT(3) +#define BCM2708_DMA_D_INC BIT(4) +#define BCM2708_DMA_D_WIDTH BIT(5) +#define BCM2708_DMA_D_DREQ BIT(6) +#define BCM2708_DMA_S_INC BIT(8) +#define BCM2708_DMA_S_WIDTH BIT(9) +#define BCM2708_DMA_S_DREQ BIT(10) + +#define BCM2708_DMA_BURST(x) (((x) & 0xf) << 12) +#define BCM2708_DMA_PER_MAP(x) ((x) << 16) +#define BCM2708_DMA_WAITS(x) (((x) & 0x1f) << 21) + +#define BCM2708_DMA_DREQ_EMMC 11 +#define BCM2708_DMA_DREQ_SDHOST 13 + +#define BCM2708_DMA_CS 0x00 /* Control and Status */ +#define BCM2708_DMA_ADDR 0x04 +/* the current control block appears in the following registers - read only */ +#define BCM2708_DMA_INFO 0x08 +#define BCM2708_DMA_SOURCE_AD 0x0c +#define BCM2708_DMA_DEST_AD 0x10 +#define BCM2708_DMA_NEXTCB 0x1C +#define BCM2708_DMA_DEBUG 0x20 + +#define BCM2708_DMA4_CS (BCM2708_DMA_CHAN(4) + BCM2708_DMA_CS) +#define BCM2708_DMA4_ADDR (BCM2708_DMA_CHAN(4) + BCM2708_DMA_ADDR) + +#define BCM2708_DMA_TDMODE_LEN(w, h) ((h) << 16 | (w)) + +/* When listing features we can ask for when allocating DMA channels give + 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 BIT(BCM_DMA_FEATURE_FAST_ORD) +#define BCM_DMA_FEATURE_BULK BIT(BCM_DMA_FEATURE_BULK_ORD) +#define BCM_DMA_FEATURE_NORMAL BIT(BCM_DMA_FEATURE_NORMAL_ORD) +#define BCM_DMA_FEATURE_LITE BIT(BCM_DMA_FEATURE_LITE_ORD) +#define BCM_DMA_FEATURE_COUNT 4 + +struct bcm2708_dma_cb { + unsigned long info; + unsigned long src; + unsigned long dst; + unsigned long length; + unsigned long stride; + unsigned long next; + unsigned long pad[2]; +}; + +struct scatterlist; + +#ifdef CONFIG_DMA_BCM2708_LEGACY + +int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len); +void bcm_dma_start(void __iomem *dma_chan_base, dma_addr_t control_block); +void bcm_dma_wait_idle(void __iomem *dma_chan_base); +bool bcm_dma_is_busy(void __iomem *dma_chan_base); +int bcm_dma_abort(void __iomem *dma_chan_base); + +/* return channel no or -ve error */ +int bcm_dma_chan_alloc(unsigned preferred_feature_set, + void __iomem **out_dma_base, int *out_dma_irq); +int bcm_dma_chan_free(int channel); + +#else /* CONFIG_DMA_BCM2708_LEGACY */ + +static inline int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, + int sg_len) +{ + return 0; +} + +static inline void bcm_dma_start(void __iomem *dma_chan_base, + dma_addr_t control_block) { } + +static inline void bcm_dma_wait_idle(void __iomem *dma_chan_base) { } + +static inline bool bcm_dma_is_busy(void __iomem *dma_chan_base) +{ + return false; +} + +static inline int bcm_dma_abort(void __iomem *dma_chan_base) +{ + return -EINVAL; +} + +static inline int bcm_dma_chan_alloc(unsigned preferred_feature_set, + void __iomem **out_dma_base, + int *out_dma_irq) +{ + return -EINVAL; +} + +static inline int bcm_dma_chan_free(int channel) +{ + return -EINVAL; +} + +#endif /* CONFIG_DMA_BCM2708_LEGACY */ + +#endif /* _PLAT_BCM2708_DMA_H */