| Message ID | 1310546857-6304-6-git-send-email-kgene.kim@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 13, 2011 at 05:47:30PM +0900, Kukjin Kim wrote: > From: Boojin Kim <boojin.kim@samsung.com> > > This patch adds common DMA operations which are used for Samsung DMA > drivers. Currently there are two types of DMA driver for Samsung SoCs. > The one is S3C-DMA for S3C SoCs and the other is PL330-DMA for S5P SoCs. > This patch provides funcion pointers for common DMA operations to DMA > client driver like SPI and Audio. It makes DMA client drivers support > multi-platform. > In addition, this common DMA operations implement the shared actions > that are needed for DMA client driver. For example shared actions are > filter() function for dma_request_channel() and parameter passing for > device_prep_slave_sg(). > > Signed-off-by: Boojin Kim <boojin.kim@samsung.com> > Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> > --- > arch/arm/mach-s3c2410/include/mach/dma.h | 3 +- > arch/arm/plat-samsung/Makefile | 6 +- > arch/arm/plat-samsung/dma-ops.c | 131 +++++++++++++++++++++++ > arch/arm/plat-samsung/include/plat/dma-ops.h | 47 +++++++++ > arch/arm/plat-samsung/include/plat/dma-pl330.h | 3 + > arch/arm/plat-samsung/include/plat/dma.h | 2 +- > arch/arm/plat-samsung/s3c-dma-ops.c | 132 ++++++++++++++++++++++++ > 7 files changed, 320 insertions(+), 4 deletions(-) > create mode 100644 arch/arm/plat-samsung/dma-ops.c > create mode 100644 arch/arm/plat-samsung/include/plat/dma-ops.h > create mode 100644 arch/arm/plat-samsung/s3c-dma-ops.c > > diff --git a/arch/arm/mach-s3c2410/include/mach/dma.h b/arch/arm/mach-s3c2410/include/mach/dma.h > index b2b2a5b..71a662d 100644 > --- a/arch/arm/mach-s3c2410/include/mach/dma.h > +++ b/arch/arm/mach-s3c2410/include/mach/dma.h > @@ -13,7 +13,6 @@ > #ifndef __ASM_ARCH_DMA_H > #define __ASM_ARCH_DMA_H __FILE__ > > -#include <plat/dma.h> > #include <linux/sysdev.h> > > #define MAX_DMA_TRANSFER_SIZE 0x100000 /* Data Unit is half word */ > @@ -51,6 +50,8 @@ enum dma_ch { > DMACH_MAX, /* the end entry */ > }; > > +#include <plat/dma.h> > + > #define DMACH_LOW_LEVEL (1<<28) /* use this to specifiy hardware ch no */ > > /* we have 4 dma channels */ > diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile > index 53eb15b..9ecf2aa 100644 > --- a/arch/arm/plat-samsung/Makefile > +++ b/arch/arm/plat-samsung/Makefile > @@ -62,9 +62,11 @@ obj-$(CONFIG_SAMSUNG_DEV_PWM) += dev-pwm.o > > # DMA support > > -obj-$(CONFIG_S3C_DMA) += dma.o > +obj-$(CONFIG_S3C_DMA) += dma.o s3c-dma-ops.o > > -obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o > +obj-$(CONFIG_DMADEV_PL330) += dma-ops.o > + > +obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o s3c-dma-ops.o > > # PM support > > diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c > new file mode 100644 > index 0000000..94a9d33 > --- /dev/null > +++ b/arch/arm/plat-samsung/dma-ops.c > @@ -0,0 +1,131 @@ > +/* linux/arch/arm/plat-samsung/dma-ops.c > + * > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > + * Samsung DMA Operations > + * > + * 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. > +*/ > + > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <linux/dmaengine.h> > +#include <linux/amba/pl330.h> > + > +#include <mach/dma.h> > + > +static bool filter(struct dma_chan *chan, void *param) > +{ > + struct dma_pl330_peri *peri = (struct dma_pl330_peri *)chan->private; Is this code pl330 specific? If so, 'pl330' should probably be referenced in the function name. > + unsigned dma_ch = (unsigned)param; > + > + if (peri->peri_id != dma_ch) > + return false; > + > + return true; > +} > + > +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info *info) > +{ > + struct dma_chan *chan; > + dma_cap_mask_t mask; > + struct dma_slave_config slave_config; > + > + dma_cap_zero(mask); > + dma_cap_set(info->cap, mask); > + > + chan = dma_request_channel(mask, filter, (void *)dma_ch); > + > + if (info->direction == DMA_FROM_DEVICE) { > + memset(&slave_config, 0, sizeof(struct dma_slave_config)); > + slave_config.direction = info->direction; > + slave_config.src_addr = info->fifo; > + slave_config.src_addr_width = info->width; > + dmaengine_slave_config(chan, &slave_config); > + } else if (info->direction == DMA_TO_DEVICE) { > + memset(&slave_config, 0, sizeof(struct dma_slave_config)); > + slave_config.direction = info->direction; > + slave_config.dst_addr = info->fifo; > + slave_config.dst_addr_width = info->width; > + dmaengine_slave_config(chan, &slave_config); > + } > + > + return (unsigned)chan; > +} > + > +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) > +{ > + dma_release_channel((struct dma_chan *)ch); > + > + return 0; > +} > + > +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) > +{ > + struct scatterlist sg; > + struct dma_chan *chan = (struct dma_chan *)ch; > + struct dma_async_tx_descriptor *desc; > + > + switch (info->cap) { > + case DMA_SLAVE: > + sg_init_table(&sg, 1); > + sg_dma_len(&sg) = info->len; > + sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)), > + info->len, offset_in_page(info->buf)); > + sg_dma_address(&sg) = info->buf; > + > + desc = chan->device->device_prep_slave_sg(chan, > + &sg, 1, info->direction, DMA_PREP_INTERRUPT); > + break; > + case DMA_CYCLIC: > + desc = chan->device->device_prep_dma_cyclic(chan, > + info->buf, info->len, info->period, info->direction); > + break; > + default: > + dev_err(&chan->dev->device, "unsupported format\n"); > + return -EFAULT; > + } > + > + if (!desc) { > + dev_err(&chan->dev->device, "cannot prepare cyclic dma\n"); > + return -EFAULT; > + } > + > + desc->callback = info->fp; > + desc->callback_param = info->fp_param; > + > + dmaengine_submit((struct dma_async_tx_descriptor *)desc); > + > + return 0; > +} > + > +static inline int dma_trigger(unsigned ch) > +{ > + dma_async_issue_pending((struct dma_chan *)ch); > + > + return 0; > +} > + > +static inline int dma_flush(unsigned ch) > +{ > + return dmaengine_terminate_all((struct dma_chan *)ch); > +} > + > +static struct samsung_dma_ops dmaeng_ops = { > + .request = dma_request, > + .release = dma_release, > + .prepare = dma_prepare, > + .trigger = dma_trigger, > + .started = NULL, > + .flush = dma_flush, > + .stop = dma_flush, > +}; Even though these function are all local statics, you should use a samsung prefix to avoid namespace collisions. So, they should be named something like: samsung_dmaeng_ops, samsung_dmaeng_request(), samsung_dmaeng_release(), etc. The ops structure and the functions should have the same prefix. > + > +void *samsung_dma_get_ops(void) > +{ > + return (void *)&dmaeng_ops; > +} > +EXPORT_SYMBOL(samsung_dma_get_ops); If all that is needed is a reference to the dma ops, then you could simply export samsung_dmaeng_ops() without a separate function. > diff --git a/arch/arm/plat-samsung/include/plat/dma-ops.h b/arch/arm/plat-samsung/include/plat/dma-ops.h > new file mode 100644 > index 0000000..eea4130 > --- /dev/null > +++ b/arch/arm/plat-samsung/include/plat/dma-ops.h > @@ -0,0 +1,47 @@ > +/* arch/arm/plat-samsung/include/plat/dma-ops.h > + * > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > + * Samsung DMA support > + * > + * 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. > +*/ > + > +#include <linux/dmaengine.h> > + > +struct samsung_dma_prep_info { > + enum dma_transaction_type cap; > + enum dma_data_direction direction; > + unsigned buf; > + unsigned long period; > + unsigned long len; > + void (*fp)(void *data); > + void *fp_param; > +}; > + > +struct samsung_dma_info { > + enum dma_transaction_type cap; > + enum dma_data_direction direction; > + enum dma_slave_buswidth width; > + unsigned fifo; > + struct s3c2410_dma_client *client; > +}; > + > +struct samsung_dma_ops { > + unsigned (*request)(enum dma_ch ch, struct samsung_dma_info *info); > + int (*release)(unsigned ch, struct s3c2410_dma_client *client); > + int (*prepare)(unsigned ch, struct samsung_dma_prep_info *info); > + int (*trigger)(unsigned ch); > + int (*started)(unsigned ch); > + int (*flush)(unsigned ch); > + int (*stop)(unsigned ch); > +}; > + > +/* > + * samsung_dma_get_ops > + * get the set of dma operations > + */ > +extern void *samsung_dma_get_ops(void); > diff --git a/arch/arm/plat-samsung/include/plat/dma-pl330.h b/arch/arm/plat-samsung/include/plat/dma-pl330.h > index c402719..be84bec 100644 > --- a/arch/arm/plat-samsung/include/plat/dma-pl330.h > +++ b/arch/arm/plat-samsung/include/plat/dma-pl330.h > @@ -1,4 +1,7 @@ > /* > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > * Copyright (C) 2010 Samsung Electronics Co. Ltd. > * Jaswinder Singh <jassi.brar@samsung.com> > * Heh, this patch doesn't make any changes to this file, and samsung already has a copyright notice on it anyway. You should probably drop this hunk. > diff --git a/arch/arm/plat-samsung/include/plat/dma.h b/arch/arm/plat-samsung/include/plat/dma.h > index 2e8f8c6..90da162 100644 > --- a/arch/arm/plat-samsung/include/plat/dma.h > +++ b/arch/arm/plat-samsung/include/plat/dma.h > @@ -124,4 +124,4 @@ extern int s3c2410_dma_getposition(unsigned int channel, > extern int s3c2410_dma_set_opfn(unsigned int, s3c2410_dma_opfn_t rtn); > extern int s3c2410_dma_set_buffdone_fn(unsigned int, s3c2410_dma_cbfn_t rtn); > > - nitpick: Unrelated whitespace change. One blank line of whitespace is sufficient anyway. > +#include <plat/dma-ops.h> > diff --git a/arch/arm/plat-samsung/s3c-dma-ops.c b/arch/arm/plat-samsung/s3c-dma-ops.c > new file mode 100644 > index 0000000..17b1be0 > --- /dev/null > +++ b/arch/arm/plat-samsung/s3c-dma-ops.c > @@ -0,0 +1,132 @@ > +/* linux/arch/arm/plat-samsung/s3c-dma-ops.c > + * > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > + * Samsung S3C-DMA Operations > + * > + * 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. > +*/ > + > +#include <linux/kernel.h> > +#include <linux/errno.h> > +#include <linux/slab.h> > +#include <linux/types.h> > + > +#include <mach/dma.h> > + > +struct cb_data { struct s3c2410_cb_data { > + void (*fp) (void *); > + void *fp_param; > + unsigned ch; > + struct list_head node; > +}; > + > +static LIST_HEAD(dma_list); > + > +static void dma_cb(struct s3c2410_dma_chan *channel, > + void *param, int size, enum s3c2410_dma_buffresult res) > +{ > + struct cb_data *data = (struct cb_data *)param; param is a void*. The (struct cb_data*) cast is not needed. > + > + data->fp(data->fp_param); > +} > + > +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info *info) These functions should *definitely* be named differently from the dma_* ops in the other file so that you can differentiate between them, and to make them grep-friendly. This goes for *all* file-scope symbols. > +{ > + struct cb_data *data; > + > + if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) { > + s3c2410_dma_free(dma_ch, info->client); > + return 0; > + } > + > + data = kmalloc(sizeof(struct cb_data), GFP_KERNEL); kzalloc() > + data->fp = NULL; Drop this line after converting to kzalloc() > + data->ch = (unsigned)dma_ch; Is the cast necessary? > + list_add_tail(&data->node, &dma_list); > + > + if (info->direction == DMA_FROM_DEVICE) > + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_HW, info->fifo); > + else > + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_MEM, info->fifo); From arch/arm/plat-samsung/include/plat/dma.h: enum s3c2410_dmasrc { S3C2410_DMASRC_HW, /* source is memory */ S3C2410_DMASRC_MEM /* source is hardware */ }; from dma-mapping.h: enum dma_data_direction { DMA_BIDIRECTIONAL = 0, DMA_TO_DEVICE = 1, DMA_FROM_DEVICE = 2, DMA_NONE = 3, }; /me thinks it would all look nicer if s3c2410 dma just replaced s3c2410_dmasrc to dma_data_direction, and from what I can tell it would just be a simple search and replace. :-) > + > + if (info->cap == DMA_CYCLIC) > + s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR); > + > + s3c2410_dma_config(dma_ch, info->width); > + > + return (unsigned)dma_ch; > +} > + > +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) unsigned int > +{ > + struct cb_data *data; > + > + list_for_each_entry(data, &dma_list, node) > + if (data->ch == ch) > + break; nit: incorrect indentation. Use tab characters instead of spaces. I've got "set list" and "set listchars=tab:\|-,trail:-" in my ~/.vimrc so I can see the difference between tabs and spaces. > + list_del(&data->node); What happens if the channel isn't found in the list? Can that situation happen? What happens if two drivers call dma_release simultaneously? It looks like a mutex is needed to protext the dma_list. > + > + s3c2410_dma_free((enum dma_ch)ch, client); All the casting in this patch makes me nervous. When a lot of casting is required, I wonder if the API needs to be changed. > + kfree(data); > + > + return 0; > +} > + > +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) > +{ > + struct cb_data *data; > + > + list_for_each_entry(data, &dma_list, node) > + if (data->ch == ch) > + break; > + > + if (!data->fp) { > + s3c2410_dma_set_buffdone_fn((enum dma_ch)ch, dma_cb); > + data->fp = info->fp; > + data->fp_param = info->fp_param; > + } > + s3c2410_dma_enqueue((enum dma_ch)ch, (void *)data, info->buf, > + info->period); > + > + return 0; > +} > + > +static inline int dma_trigger(unsigned ch) > +{ > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START); > +} > + > +static inline int dma_started(unsigned ch) > +{ > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED); > +} > + > +static inline int dma_flush(unsigned ch) > +{ > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH); > +} > + > +static inline int dma_stop(unsigned ch) > +{ > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP); > +} > + > +static struct samsung_dma_ops s3c_dma_ops = { > + .request = dma_request, > + .release = dma_release, > + .prepare = dma_prepare, > + .trigger = dma_trigger, > + .started = dma_started, > + .flush = dma_flush, > + .stop = dma_stop, > +}; > + > +void *samsung_dma_get_ops(void) > +{ > + return (void *)&s3c_dma_ops; > +} > +EXPORT_SYMBOL(samsung_dma_get_ops); This is a problem. This patch adds two implementations of samsung_dma_get_ops(). New code needs to be multiplatform friendly. That means that the code nees to handle both dma-ops.c and s3c-dma-ops.c compiled into the kernel at the same time and select the correct one at runtime. g. > -- > 1.7.1 >
Grant Likely wrote: > On Wed, Jul 13, 2011 at 05:47:30PM +0900, Kukjin Kim wrote: > > From: Boojin Kim <boojin.kim@samsung.com> > > > > This patch adds common DMA operations which are used for Samsung DMA > > drivers. Currently there are two types of DMA driver for Samsung SoCs. > > The one is S3C-DMA for S3C SoCs and the other is PL330-DMA for S5P SoCs. > > This patch provides funcion pointers for common DMA operations to DMA > > client driver like SPI and Audio. It makes DMA client drivers support > > multi-platform. > > In addition, this common DMA operations implement the shared actions > > that are needed for DMA client driver. For example shared actions are > > filter() function for dma_request_channel() and parameter passing for > > device_prep_slave_sg(). > > > > Signed-off-by: Boojin Kim <boojin.kim@samsung.com> > > Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> > > --- > > arch/arm/mach-s3c2410/include/mach/dma.h | 3 +- > > arch/arm/plat-samsung/Makefile | 6 +- > > arch/arm/plat-samsung/dma-ops.c | 131 > +++++++++++++++++++++++ > > arch/arm/plat-samsung/include/plat/dma-ops.h | 47 +++++++++ > > arch/arm/plat-samsung/include/plat/dma-pl330.h | 3 + > > arch/arm/plat-samsung/include/plat/dma.h | 2 +- > > arch/arm/plat-samsung/s3c-dma-ops.c | 132 > ++++++++++++++++++++++++ > > 7 files changed, 320 insertions(+), 4 deletions(-) > > create mode 100644 arch/arm/plat-samsung/dma-ops.c > > create mode 100644 arch/arm/plat-samsung/include/plat/dma-ops.h > > create mode 100644 arch/arm/plat-samsung/s3c-dma-ops.c > > > > diff --git a/arch/arm/mach-s3c2410/include/mach/dma.h b/arch/arm/mach- > s3c2410/include/mach/dma.h > > index b2b2a5b..71a662d 100644 > > --- a/arch/arm/mach-s3c2410/include/mach/dma.h > > +++ b/arch/arm/mach-s3c2410/include/mach/dma.h > > @@ -13,7 +13,6 @@ > > #ifndef __ASM_ARCH_DMA_H > > #define __ASM_ARCH_DMA_H __FILE__ > > > > -#include <plat/dma.h> > > #include <linux/sysdev.h> > > > > #define MAX_DMA_TRANSFER_SIZE 0x100000 /* Data Unit is half word */ > > @@ -51,6 +50,8 @@ enum dma_ch { > > DMACH_MAX, /* the end entry */ > > }; > > > > +#include <plat/dma.h> > > + > > #define DMACH_LOW_LEVEL (1<<28) /* use this to specifiy hardware > ch no */ > > > > /* we have 4 dma channels */ > > diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat- > samsung/Makefile > > index 53eb15b..9ecf2aa 100644 > > --- a/arch/arm/plat-samsung/Makefile > > +++ b/arch/arm/plat-samsung/Makefile > > @@ -62,9 +62,11 @@ obj-$(CONFIG_SAMSUNG_DEV_PWM) += dev-pwm.o > > > > # DMA support > > > > -obj-$(CONFIG_S3C_DMA) += dma.o > > +obj-$(CONFIG_S3C_DMA) += dma.o s3c-dma-ops.o > > > > -obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o > > +obj-$(CONFIG_DMADEV_PL330) += dma-ops.o > > + > > +obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o s3c-dma-ops.o > > > > # PM support > > > > diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat- > samsung/dma-ops.c > > new file mode 100644 > > index 0000000..94a9d33 > > --- /dev/null > > +++ b/arch/arm/plat-samsung/dma-ops.c > > @@ -0,0 +1,131 @@ > > +/* linux/arch/arm/plat-samsung/dma-ops.c > > + * > > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com > > + * > > + * Samsung DMA Operations > > + * > > + * 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. > > +*/ > > + > > +#include <linux/kernel.h> > > +#include <linux/errno.h> > > +#include <linux/dmaengine.h> > > +#include <linux/amba/pl330.h> > > + > > +#include <mach/dma.h> > > + > > +static bool filter(struct dma_chan *chan, void *param) > > +{ > > + struct dma_pl330_peri *peri = (struct dma_pl330_peri *)chan- > >private; > > Is this code pl330 specific? If so, 'pl330' should probably be > referenced in the function name. I will address your comment. > > > + unsigned dma_ch = (unsigned)param; > > + > > + if (peri->peri_id != dma_ch) > > + return false; > > + > > + return true; > > +} > > + > > +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info > *info) > > +{ > > + struct dma_chan *chan; > > + dma_cap_mask_t mask; > > + struct dma_slave_config slave_config; > > + > > + dma_cap_zero(mask); > > + dma_cap_set(info->cap, mask); > > + > > + chan = dma_request_channel(mask, filter, (void *)dma_ch); > > + > > + if (info->direction == DMA_FROM_DEVICE) { > > + memset(&slave_config, 0, sizeof(struct dma_slave_config)); > > + slave_config.direction = info->direction; > > + slave_config.src_addr = info->fifo; > > + slave_config.src_addr_width = info->width; > > + dmaengine_slave_config(chan, &slave_config); > > + } else if (info->direction == DMA_TO_DEVICE) { > > + memset(&slave_config, 0, sizeof(struct dma_slave_config)); > > + slave_config.direction = info->direction; > > + slave_config.dst_addr = info->fifo; > > + slave_config.dst_addr_width = info->width; > > + dmaengine_slave_config(chan, &slave_config); > > + } > > + > > + return (unsigned)chan; > > +} > > + > > +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) > > +{ > > + dma_release_channel((struct dma_chan *)ch); > > + > > + return 0; > > +} > > + > > +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) > > +{ > > + struct scatterlist sg; > > + struct dma_chan *chan = (struct dma_chan *)ch; > > + struct dma_async_tx_descriptor *desc; > > + > > + switch (info->cap) { > > + case DMA_SLAVE: > > + sg_init_table(&sg, 1); > > + sg_dma_len(&sg) = info->len; > > + sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)), > > + info->len, offset_in_page(info->buf)); > > + sg_dma_address(&sg) = info->buf; > > + > > + desc = chan->device->device_prep_slave_sg(chan, > > + &sg, 1, info->direction, DMA_PREP_INTERRUPT); > > + break; > > + case DMA_CYCLIC: > > + desc = chan->device->device_prep_dma_cyclic(chan, > > + info->buf, info->len, info->period, info->direction); > > + break; > > + default: > > + dev_err(&chan->dev->device, "unsupported format\n"); > > + return -EFAULT; > > + } > > + > > + if (!desc) { > > + dev_err(&chan->dev->device, "cannot prepare cyclic dma\n"); > > + return -EFAULT; > > + } > > + > > + desc->callback = info->fp; > > + desc->callback_param = info->fp_param; > > + > > + dmaengine_submit((struct dma_async_tx_descriptor *)desc); > > + > > + return 0; > > +} > > + > > +static inline int dma_trigger(unsigned ch) > > +{ > > + dma_async_issue_pending((struct dma_chan *)ch); > > + > > + return 0; > > +} > > + > > +static inline int dma_flush(unsigned ch) > > +{ > > + return dmaengine_terminate_all((struct dma_chan *)ch); > > +} > > + > > +static struct samsung_dma_ops dmaeng_ops = { > > + .request = dma_request, > > + .release = dma_release, > > + .prepare = dma_prepare, > > + .trigger = dma_trigger, > > + .started = NULL, > > + .flush = dma_flush, > > + .stop = dma_flush, > > +}; > > Even though these function are all local statics, you should use a > samsung prefix to avoid namespace collisions. So, they should be > named something like: samsung_dmaeng_ops, samsung_dmaeng_request(), > samsung_dmaeng_release(), etc. The ops structure and the functions > should have the same prefix. I will address your comment. > > > + > > +void *samsung_dma_get_ops(void) > > +{ > > + return (void *)&dmaeng_ops; > > +} > > +EXPORT_SYMBOL(samsung_dma_get_ops); > > If all that is needed is a reference to the dma ops, then you could > simply export samsung_dmaeng_ops() without a separate function. Grant, Thanks for your comments. I can't understand this comment well. Do you mean to change function name from 'samsung_dma_get_ops()' to 'samsung_dmaeng_ops()' ? Or export 'dmaeng_ops' variable instead of making this 'samsung_dma_get_ops()' function > > > diff --git a/arch/arm/plat-samsung/include/plat/dma-ops.h > b/arch/arm/plat-samsung/include/plat/dma-ops.h > > new file mode 100644 > > index 0000000..eea4130 > > --- /dev/null > > +++ b/arch/arm/plat-samsung/include/plat/dma-ops.h > > @@ -0,0 +1,47 @@ > > +/* arch/arm/plat-samsung/include/plat/dma-ops.h > > + * > > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com > > + * > > + * Samsung DMA support > > + * > > + * 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. > > +*/ > > + > > +#include <linux/dmaengine.h> > > + > > +struct samsung_dma_prep_info { > > + enum dma_transaction_type cap; > > + enum dma_data_direction direction; > > + unsigned buf; > > + unsigned long period; > > + unsigned long len; > > + void (*fp)(void *data); > > + void *fp_param; > > +}; > > + > > +struct samsung_dma_info { > > + enum dma_transaction_type cap; > > + enum dma_data_direction direction; > > + enum dma_slave_buswidth width; > > + unsigned fifo; > > + struct s3c2410_dma_client *client; > > +}; > > + > > +struct samsung_dma_ops { > > + unsigned (*request)(enum dma_ch ch, struct samsung_dma_info *info); > > + int (*release)(unsigned ch, struct s3c2410_dma_client *client); > > + int (*prepare)(unsigned ch, struct samsung_dma_prep_info *info); > > + int (*trigger)(unsigned ch); > > + int (*started)(unsigned ch); > > + int (*flush)(unsigned ch); > > + int (*stop)(unsigned ch); > > +}; > > + > > +/* > > + * samsung_dma_get_ops > > + * get the set of dma operations > > + */ > > +extern void *samsung_dma_get_ops(void); > > diff --git a/arch/arm/plat-samsung/include/plat/dma-pl330.h > b/arch/arm/plat-samsung/include/plat/dma-pl330.h > > index c402719..be84bec 100644 > > --- a/arch/arm/plat-samsung/include/plat/dma-pl330.h > > +++ b/arch/arm/plat-samsung/include/plat/dma-pl330.h > > @@ -1,4 +1,7 @@ > > /* > > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com > > + * > > * Copyright (C) 2010 Samsung Electronics Co. Ltd. > > * Jaswinder Singh <jassi.brar@samsung.com> > > * > > > Heh, this patch doesn't make any changes to this file, and samsung > already has a copyright notice on it anyway. You should probably drop > this hunk. I will address your comment. > > > diff --git a/arch/arm/plat-samsung/include/plat/dma.h b/arch/arm/plat- > samsung/include/plat/dma.h > > index 2e8f8c6..90da162 100644 > > --- a/arch/arm/plat-samsung/include/plat/dma.h > > +++ b/arch/arm/plat-samsung/include/plat/dma.h > > @@ -124,4 +124,4 @@ extern int s3c2410_dma_getposition(unsigned int > channel, > > extern int s3c2410_dma_set_opfn(unsigned int, s3c2410_dma_opfn_t rtn); > > extern int s3c2410_dma_set_buffdone_fn(unsigned int, s3c2410_dma_cbfn_t > rtn); > > > > - > > nitpick: Unrelated whitespace change. One blank line of whitespace is > sufficient anyway. I will address your comment. > > +#include <plat/dma-ops.h> > > diff --git a/arch/arm/plat-samsung/s3c-dma-ops.c b/arch/arm/plat- > samsung/s3c-dma-ops.c > > new file mode 100644 > > index 0000000..17b1be0 > > --- /dev/null > > +++ b/arch/arm/plat-samsung/s3c-dma-ops.c > > @@ -0,0 +1,132 @@ > > +/* linux/arch/arm/plat-samsung/s3c-dma-ops.c > > + * > > + * Copyright (c) 2011 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com > > + * > > + * Samsung S3C-DMA Operations > > + * > > + * 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. > > +*/ > > + > > +#include <linux/kernel.h> > > +#include <linux/errno.h> > > +#include <linux/slab.h> > > +#include <linux/types.h> > > + > > +#include <mach/dma.h> > > + > > +struct cb_data { > > struct s3c2410_cb_data { > > > + void (*fp) (void *); > > + void *fp_param; > > + unsigned ch; > > + struct list_head node; > > +}; > > + > > +static LIST_HEAD(dma_list); > > + > > +static void dma_cb(struct s3c2410_dma_chan *channel, > > + void *param, int size, enum s3c2410_dma_buffresult res) > > +{ > > + struct cb_data *data = (struct cb_data *)param; > > param is a void*. The (struct cb_data*) cast is not needed. > > > + > > + data->fp(data->fp_param); > > +} > > + > > +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info > *info) > > These functions should *definitely* be named differently from the > dma_* ops in the other file so that you can differentiate between > them, and to make them grep-friendly. This goes for *all* file-scope > symbols. I will address your comment. > > > +{ > > + struct cb_data *data; > > + > > + if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) { > > + s3c2410_dma_free(dma_ch, info->client); > > + return 0; > > + } > > + > > + data = kmalloc(sizeof(struct cb_data), GFP_KERNEL); > > kzalloc() > > > + data->fp = NULL; > > Drop this line after converting to kzalloc() I will address your comment. > > > + data->ch = (unsigned)dma_ch; > > Is the cast necessary? > > > + list_add_tail(&data->node, &dma_list); > > + > > + if (info->direction == DMA_FROM_DEVICE) > > + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_HW, info->fifo); > > + else > > + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_MEM, info- > >fifo); > > From arch/arm/plat-samsung/include/plat/dma.h: > enum s3c2410_dmasrc { > S3C2410_DMASRC_HW, /* source is memory */ > S3C2410_DMASRC_MEM /* source is hardware */ > }; > > from dma-mapping.h: > enum dma_data_direction { > DMA_BIDIRECTIONAL = 0, > DMA_TO_DEVICE = 1, > DMA_FROM_DEVICE = 2, > DMA_NONE = 3, > }; > > /me thinks it would all look nicer if s3c2410 dma just replaced > s3c2410_dmasrc to dma_data_direction, and from what I can tell it > would just be a simple search and replace. :-) > I will address your comment. > > + > > + if (info->cap == DMA_CYCLIC) > > + s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR); > > + > > + s3c2410_dma_config(dma_ch, info->width); > > + > > + return (unsigned)dma_ch; > > +} > > + > > +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) > > unsigned int > > > +{ > > + struct cb_data *data; > > + > > + list_for_each_entry(data, &dma_list, node) > > + if (data->ch == ch) > > + break; > > nit: incorrect indentation. Use tab characters instead of spaces. > I've got "set list" and "set listchars=tab:\|-,trail:-" in my ~/.vimrc > so I can see the difference between tabs and spaces. > I will address your comment. > > + list_del(&data->node); > > What happens if the channel isn't found in the list? Can that > situation happen? > > What happens if two drivers call dma_release simultaneously? It > looks like a mutex is needed to protext the dma_list. > > > + > > + s3c2410_dma_free((enum dma_ch)ch, client); > > All the casting in this patch makes me nervous. When a lot of casting > is required, I wonder if the API needs to be changed. I will remove casting to "enum dma_ch" > > > + kfree(data); > > + > > + return 0; > > +} > > + > > +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) > > +{ > > + struct cb_data *data; > > + > > + list_for_each_entry(data, &dma_list, node) > > + if (data->ch == ch) > > + break; > > + > > + if (!data->fp) { > > + s3c2410_dma_set_buffdone_fn((enum dma_ch)ch, dma_cb); > > + data->fp = info->fp; > > + data->fp_param = info->fp_param; > > + } > > + s3c2410_dma_enqueue((enum dma_ch)ch, (void *)data, info->buf, > > + info->period); > > + > > + return 0; > > +} > > + > > +static inline int dma_trigger(unsigned ch) > > +{ > > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START); > > +} > > + > > +static inline int dma_started(unsigned ch) > > +{ > > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED); > > +} > > + > > +static inline int dma_flush(unsigned ch) > > +{ > > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH); > > +} > > + > > +static inline int dma_stop(unsigned ch) > > +{ > > + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP); > > +} > > + > > +static struct samsung_dma_ops s3c_dma_ops = { > > + .request = dma_request, > > + .release = dma_release, > > + .prepare = dma_prepare, > > + .trigger = dma_trigger, > > + .started = dma_started, > > + .flush = dma_flush, > > + .stop = dma_stop, > > +}; > > + > > +void *samsung_dma_get_ops(void) > > +{ > > + return (void *)&s3c_dma_ops; > > +} > > +EXPORT_SYMBOL(samsung_dma_get_ops); > > This is a problem. This patch adds two implementations of > samsung_dma_get_ops(). New code needs to be multiplatform friendly. > That means that the code nees to handle both dma-ops.c and > s3c-dma-ops.c compiled into the kernel at the same time and select the > correct one at runtime. > I will address your comment. > g. > > > -- > > 1.7.1 > >
On Sat, Jul 16, 2011 at 09:39:31AM +0900, Boojin Kim wrote: > Grant Likely wrote: > > > +void *samsung_dma_get_ops(void) > > > +{ > > > + return (void *)&dmaeng_ops; > > > +} > > > +EXPORT_SYMBOL(samsung_dma_get_ops); > > > > If all that is needed is a reference to the dma ops, then you could > > simply export samsung_dmaeng_ops() without a separate function. > > Grant, Thanks for your comments. I can't understand this comment well. > Do you mean to change function name from 'samsung_dma_get_ops()' to > 'samsung_dmaeng_ops()' ? > Or export 'dmaeng_ops' variable instead of making this > 'samsung_dma_get_ops()' function I mean export dmaeng_ops instead of using a function. You also get some type checking by not casting it into a (void*).
diff --git a/arch/arm/mach-s3c2410/include/mach/dma.h b/arch/arm/mach-s3c2410/include/mach/dma.h index b2b2a5b..71a662d 100644 --- a/arch/arm/mach-s3c2410/include/mach/dma.h +++ b/arch/arm/mach-s3c2410/include/mach/dma.h @@ -13,7 +13,6 @@ #ifndef __ASM_ARCH_DMA_H #define __ASM_ARCH_DMA_H __FILE__ -#include <plat/dma.h> #include <linux/sysdev.h> #define MAX_DMA_TRANSFER_SIZE 0x100000 /* Data Unit is half word */ @@ -51,6 +50,8 @@ enum dma_ch { DMACH_MAX, /* the end entry */ }; +#include <plat/dma.h> + #define DMACH_LOW_LEVEL (1<<28) /* use this to specifiy hardware ch no */ /* we have 4 dma channels */ diff --git a/arch/arm/plat-samsung/Makefile b/arch/arm/plat-samsung/Makefile index 53eb15b..9ecf2aa 100644 --- a/arch/arm/plat-samsung/Makefile +++ b/arch/arm/plat-samsung/Makefile @@ -62,9 +62,11 @@ obj-$(CONFIG_SAMSUNG_DEV_PWM) += dev-pwm.o # DMA support -obj-$(CONFIG_S3C_DMA) += dma.o +obj-$(CONFIG_S3C_DMA) += dma.o s3c-dma-ops.o -obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o +obj-$(CONFIG_DMADEV_PL330) += dma-ops.o + +obj-$(CONFIG_S3C_PL330_DMA) += s3c-pl330.o s3c-dma-ops.o # PM support diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c new file mode 100644 index 0000000..94a9d33 --- /dev/null +++ b/arch/arm/plat-samsung/dma-ops.c @@ -0,0 +1,131 @@ +/* linux/arch/arm/plat-samsung/dma-ops.c + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Samsung DMA Operations + * + * 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. +*/ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/dmaengine.h> +#include <linux/amba/pl330.h> + +#include <mach/dma.h> + +static bool filter(struct dma_chan *chan, void *param) +{ + struct dma_pl330_peri *peri = (struct dma_pl330_peri *)chan->private; + unsigned dma_ch = (unsigned)param; + + if (peri->peri_id != dma_ch) + return false; + + return true; +} + +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info *info) +{ + struct dma_chan *chan; + dma_cap_mask_t mask; + struct dma_slave_config slave_config; + + dma_cap_zero(mask); + dma_cap_set(info->cap, mask); + + chan = dma_request_channel(mask, filter, (void *)dma_ch); + + if (info->direction == DMA_FROM_DEVICE) { + memset(&slave_config, 0, sizeof(struct dma_slave_config)); + slave_config.direction = info->direction; + slave_config.src_addr = info->fifo; + slave_config.src_addr_width = info->width; + dmaengine_slave_config(chan, &slave_config); + } else if (info->direction == DMA_TO_DEVICE) { + memset(&slave_config, 0, sizeof(struct dma_slave_config)); + slave_config.direction = info->direction; + slave_config.dst_addr = info->fifo; + slave_config.dst_addr_width = info->width; + dmaengine_slave_config(chan, &slave_config); + } + + return (unsigned)chan; +} + +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) +{ + dma_release_channel((struct dma_chan *)ch); + + return 0; +} + +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) +{ + struct scatterlist sg; + struct dma_chan *chan = (struct dma_chan *)ch; + struct dma_async_tx_descriptor *desc; + + switch (info->cap) { + case DMA_SLAVE: + sg_init_table(&sg, 1); + sg_dma_len(&sg) = info->len; + sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)), + info->len, offset_in_page(info->buf)); + sg_dma_address(&sg) = info->buf; + + desc = chan->device->device_prep_slave_sg(chan, + &sg, 1, info->direction, DMA_PREP_INTERRUPT); + break; + case DMA_CYCLIC: + desc = chan->device->device_prep_dma_cyclic(chan, + info->buf, info->len, info->period, info->direction); + break; + default: + dev_err(&chan->dev->device, "unsupported format\n"); + return -EFAULT; + } + + if (!desc) { + dev_err(&chan->dev->device, "cannot prepare cyclic dma\n"); + return -EFAULT; + } + + desc->callback = info->fp; + desc->callback_param = info->fp_param; + + dmaengine_submit((struct dma_async_tx_descriptor *)desc); + + return 0; +} + +static inline int dma_trigger(unsigned ch) +{ + dma_async_issue_pending((struct dma_chan *)ch); + + return 0; +} + +static inline int dma_flush(unsigned ch) +{ + return dmaengine_terminate_all((struct dma_chan *)ch); +} + +static struct samsung_dma_ops dmaeng_ops = { + .request = dma_request, + .release = dma_release, + .prepare = dma_prepare, + .trigger = dma_trigger, + .started = NULL, + .flush = dma_flush, + .stop = dma_flush, +}; + +void *samsung_dma_get_ops(void) +{ + return (void *)&dmaeng_ops; +} +EXPORT_SYMBOL(samsung_dma_get_ops); diff --git a/arch/arm/plat-samsung/include/plat/dma-ops.h b/arch/arm/plat-samsung/include/plat/dma-ops.h new file mode 100644 index 0000000..eea4130 --- /dev/null +++ b/arch/arm/plat-samsung/include/plat/dma-ops.h @@ -0,0 +1,47 @@ +/* arch/arm/plat-samsung/include/plat/dma-ops.h + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Samsung DMA support + * + * 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. +*/ + +#include <linux/dmaengine.h> + +struct samsung_dma_prep_info { + enum dma_transaction_type cap; + enum dma_data_direction direction; + unsigned buf; + unsigned long period; + unsigned long len; + void (*fp)(void *data); + void *fp_param; +}; + +struct samsung_dma_info { + enum dma_transaction_type cap; + enum dma_data_direction direction; + enum dma_slave_buswidth width; + unsigned fifo; + struct s3c2410_dma_client *client; +}; + +struct samsung_dma_ops { + unsigned (*request)(enum dma_ch ch, struct samsung_dma_info *info); + int (*release)(unsigned ch, struct s3c2410_dma_client *client); + int (*prepare)(unsigned ch, struct samsung_dma_prep_info *info); + int (*trigger)(unsigned ch); + int (*started)(unsigned ch); + int (*flush)(unsigned ch); + int (*stop)(unsigned ch); +}; + +/* + * samsung_dma_get_ops + * get the set of dma operations + */ +extern void *samsung_dma_get_ops(void); diff --git a/arch/arm/plat-samsung/include/plat/dma-pl330.h b/arch/arm/plat-samsung/include/plat/dma-pl330.h index c402719..be84bec 100644 --- a/arch/arm/plat-samsung/include/plat/dma-pl330.h +++ b/arch/arm/plat-samsung/include/plat/dma-pl330.h @@ -1,4 +1,7 @@ /* + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * * Copyright (C) 2010 Samsung Electronics Co. Ltd. * Jaswinder Singh <jassi.brar@samsung.com> * diff --git a/arch/arm/plat-samsung/include/plat/dma.h b/arch/arm/plat-samsung/include/plat/dma.h index 2e8f8c6..90da162 100644 --- a/arch/arm/plat-samsung/include/plat/dma.h +++ b/arch/arm/plat-samsung/include/plat/dma.h @@ -124,4 +124,4 @@ extern int s3c2410_dma_getposition(unsigned int channel, extern int s3c2410_dma_set_opfn(unsigned int, s3c2410_dma_opfn_t rtn); extern int s3c2410_dma_set_buffdone_fn(unsigned int, s3c2410_dma_cbfn_t rtn); - +#include <plat/dma-ops.h> diff --git a/arch/arm/plat-samsung/s3c-dma-ops.c b/arch/arm/plat-samsung/s3c-dma-ops.c new file mode 100644 index 0000000..17b1be0 --- /dev/null +++ b/arch/arm/plat-samsung/s3c-dma-ops.c @@ -0,0 +1,132 @@ +/* linux/arch/arm/plat-samsung/s3c-dma-ops.c + * + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * Samsung S3C-DMA Operations + * + * 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. +*/ + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/types.h> + +#include <mach/dma.h> + +struct cb_data { + void (*fp) (void *); + void *fp_param; + unsigned ch; + struct list_head node; +}; + +static LIST_HEAD(dma_list); + +static void dma_cb(struct s3c2410_dma_chan *channel, + void *param, int size, enum s3c2410_dma_buffresult res) +{ + struct cb_data *data = (struct cb_data *)param; + + data->fp(data->fp_param); +} + +static unsigned dma_request(enum dma_ch dma_ch, struct samsung_dma_info *info) +{ + struct cb_data *data; + + if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) { + s3c2410_dma_free(dma_ch, info->client); + return 0; + } + + data = kmalloc(sizeof(struct cb_data), GFP_KERNEL); + data->fp = NULL; + data->ch = (unsigned)dma_ch; + list_add_tail(&data->node, &dma_list); + + if (info->direction == DMA_FROM_DEVICE) + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_HW, info->fifo); + else + s3c2410_dma_devconfig(dma_ch, S3C2410_DMASRC_MEM, info->fifo); + + if (info->cap == DMA_CYCLIC) + s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR); + + s3c2410_dma_config(dma_ch, info->width); + + return (unsigned)dma_ch; +} + +static int dma_release(unsigned ch, struct s3c2410_dma_client *client) +{ + struct cb_data *data; + + list_for_each_entry(data, &dma_list, node) + if (data->ch == ch) + break; + list_del(&data->node); + + s3c2410_dma_free((enum dma_ch)ch, client); + kfree(data); + + return 0; +} + +static int dma_prepare(unsigned ch, struct samsung_dma_prep_info *info) +{ + struct cb_data *data; + + list_for_each_entry(data, &dma_list, node) + if (data->ch == ch) + break; + + if (!data->fp) { + s3c2410_dma_set_buffdone_fn((enum dma_ch)ch, dma_cb); + data->fp = info->fp; + data->fp_param = info->fp_param; + } + s3c2410_dma_enqueue((enum dma_ch)ch, (void *)data, info->buf, + info->period); + + return 0; +} + +static inline int dma_trigger(unsigned ch) +{ + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_START); +} + +static inline int dma_started(unsigned ch) +{ + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STARTED); +} + +static inline int dma_flush(unsigned ch) +{ + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_FLUSH); +} + +static inline int dma_stop(unsigned ch) +{ + return s3c2410_dma_ctrl(ch, S3C2410_DMAOP_STOP); +} + +static struct samsung_dma_ops s3c_dma_ops = { + .request = dma_request, + .release = dma_release, + .prepare = dma_prepare, + .trigger = dma_trigger, + .started = dma_started, + .flush = dma_flush, + .stop = dma_stop, +}; + +void *samsung_dma_get_ops(void) +{ + return (void *)&s3c_dma_ops; +} +EXPORT_SYMBOL(samsung_dma_get_ops);