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dma: mxs-dma: move to generic device tree binding

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Update mxs-dma driver to adopt generic DMA device tree binding.  It
calls of_dma_controller_register() with mxs specific of_dma_xlate to
get the generic DMA device tree helper support.  Then DMA clients only
need to call dma_request_slave_channel() for requesting a DMA channel
from dmaengine.

The existing way of requesting channel, clients directly call
dma_request_channel(), still work there, and will be removed after
all mxs-dma clients get converted to generic DMA device tree helper.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Shawn Guo 2013-02-26 09:42:09 +08:00
parent aaa20517c0
commit d84f638b03
1 changed files with 66 additions and 4 deletions
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70
drivers/dma/mxs-dma.c
View file

@ -27,6 +27,7 @@
#include <linux/stmp_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <asm/irq.h>
@ -139,6 +140,8 @@ struct mxs_dma_engine {
struct dma_device dma_device;
struct device_dma_parameters dma_parms;
struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS];
struct platform_device *pdev;
unsigned int nr_channels;
};
struct mxs_dma_type {
@ -350,10 +353,8 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int ret;
if (!data)
return -EINVAL;
mxs_chan->chan_irq = data->chan_irq;
if (data)
mxs_chan->chan_irq = data->chan_irq;
mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,
CCW_BLOCK_SIZE, &mxs_chan->ccw_phys,
@ -665,8 +666,55 @@ static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
return ret;
}
struct mxs_dma_filter_param {
struct device_node *of_node;
unsigned int chan_id;
};
static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param)
{
struct mxs_dma_filter_param *param = fn_param;
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_irq;
if (mxs_dma->dma_device.dev->of_node != param->of_node)
return false;
if (chan->chan_id != param->chan_id)
return false;
chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id);
if (chan_irq < 0)
return false;
mxs_chan->chan_irq = chan_irq;
return true;
}
struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data;
dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask;
struct mxs_dma_filter_param param;
if (dma_spec->args_count != 1)
return NULL;
param.of_node = ofdma->of_node;
param.chan_id = dma_spec->args[0];
if (param.chan_id >= mxs_dma->nr_channels)
return NULL;
return dma_request_channel(mask, mxs_dma_filter_fn, &param);
}
static int __init mxs_dma_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct platform_device_id *id_entry;
const struct of_device_id *of_id;
const struct mxs_dma_type *dma_type;
@ -678,6 +726,12 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
if (!mxs_dma)
return -ENOMEM;
ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels);
if (ret) {
dev_err(&pdev->dev, "failed to read dma-channels\n");
return ret;
}
of_id = of_match_device(mxs_dma_dt_ids, &pdev->dev);
if (of_id)
id_entry = of_id->data;
@ -723,6 +777,7 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
if (ret)
return ret;
mxs_dma->pdev = pdev;
mxs_dma->dma_device.dev = &pdev->dev;
/* mxs_dma gets 65535 bytes maximum sg size */
@ -743,6 +798,13 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
return ret;
}
ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma);
if (ret) {
dev_err(mxs_dma->dma_device.dev,
"failed to register controller\n");
dma_async_device_unregister(&mxs_dma->dma_device);
}
dev_info(mxs_dma->dma_device.dev, "initialized\n");
return 0;