On Thu, Apr 11, 2013 at 12:19:46AM +0200, Guennadi Liakhovetski wrote:
> This patch adds Device Tree support to the shdma driver. No special DT
> properties are used, only standard DMA DT bindings are implemented. Since
> shdma controllers reside on SoCs, their configuration is SoC-specific and
> shall be passed to the driver from the SoC platform data, using the
> auxdata procedure.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+rene...@gmail.com>
> ---
Need Arnd to review :)
>
> Note concerning the filtering parameter. Without DT slave channels are
> configured, based on a purely virtual slave ID, passed by DMA clients
> to the shdma dmaengine driver. In the DT case we cannot use such
> virtual IDs, we use a hardware MID/RID (DMA request ID) value. This is
> confusing, ideally, all existing users should be converted to also use
> MID/RID. This patch doesn't do that, it leaves existing users
> unaffected and only uses MID/RID for DT.
>
> drivers/dma/sh/shdma-base.c | 51 +++++++++++++++++++++++++++++++++++++-----
> drivers/dma/sh/shdma.c | 44 ++++++++++++++++++++++++++++++++-----
> include/linux/shdma-base.h | 5 ++++
> 3 files changed, 88 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c
> index 4acb85a..4fd8293 100644
> --- a/drivers/dma/sh/shdma-base.c
> +++ b/drivers/dma/sh/shdma-base.c
> @@ -14,6 +14,8 @@
> */
>
> #include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> #include <linux/shdma-base.h>
> #include <linux/dmaengine.h>
> #include <linux/init.h>
> @@ -175,7 +177,18 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> {
> struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
> const struct shdma_ops *ops = sdev->ops;
> - int ret;
> + int ret, match;
> +
> + if (schan->dev->of_node) {
> + match = schan->hw_req;
> + ret = ops->set_slave(schan, match, true);
> + if (ret < 0)
> + return ret;
> +
> + slave_id = schan->slave_id;
> + } else {
> + match = slave_id;
> + }
>
> if (slave_id < 0 || slave_id >= slave_num)
> return -EINVAL;
> @@ -183,7 +196,7 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> if (test_and_set_bit(slave_id, shdma_slave_used))
> return -EBUSY;
>
> - ret = ops->set_slave(schan, slave_id, false);
> + ret = ops->set_slave(schan, match, false);
> if (ret < 0) {
> clear_bit(slave_id, shdma_slave_used);
> return ret;
> @@ -206,23 +219,26 @@ static int shdma_setup_slave(struct shdma_chan *schan,
> int slave_id)
> * services would have to provide their own filters, which first would check
> * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c,
> do
> * this, and only then, in case of a match, call this common filter.
> + * NOTE 2: This filter function is also used in the DT case by shdma_xlate().
> + * In that case the MID-RID value is used for slave channel filtering and is
> + * passed to this function in the "arg" parameter.
> */
> bool shdma_chan_filter(struct dma_chan *chan, void *arg)
> {
> struct shdma_chan *schan = to_shdma_chan(chan);
> struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
> const struct shdma_ops *ops = sdev->ops;
> - int slave_id = (int)arg;
> + int match = (int)arg;
> int ret;
>
> - if (slave_id < 0)
> + if (match < 0)
> /* No slave requested - arbitrary channel */
> return true;
>
> - if (slave_id >= slave_num)
> + if (!schan->dev->of_node && match >= slave_num)
> return false;
>
> - ret = ops->set_slave(schan, slave_id, true);
> + ret = ops->set_slave(schan, match, true);
> if (ret < 0)
> return false;
>
> @@ -867,6 +883,29 @@ void shdma_chan_remove(struct shdma_chan *schan)
> }
> EXPORT_SYMBOL(shdma_chan_remove);
>
> +struct dma_chan *shdma_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + struct shdma_dev *sdev = ofdma->of_dma_data;
> + u32 id = dma_spec->args[0];
> + dma_cap_mask_t mask;
> + struct dma_chan *chan;
> +
> + if (dma_spec->args_count != 1 || !sdev)
> + return NULL;
> +
> + dma_cap_zero(mask);
> + /* Only slave DMA channels can be allocated via DT */
> + dma_cap_set(DMA_SLAVE, mask);
> +
> + chan = dma_request_channel(mask, shdma_chan_filter, (void *)id);
> + if (chan)
> + to_shdma_chan(chan)->hw_req = id;
> +
> + return chan;
> +}
> +EXPORT_SYMBOL(shdma_xlate);
> +
> int shdma_init(struct device *dev, struct shdma_dev *sdev,
> int chan_num)
> {
> diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
> index a5a1887..db497d6 100644
> --- a/drivers/dma/sh/shdma.c
> +++ b/drivers/dma/sh/shdma.c
> @@ -20,6 +20,8 @@
>
> #include <linux/init.h>
> #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> #include <linux/slab.h>
> #include <linux/interrupt.h>
> #include <linux/dmaengine.h>
> @@ -301,20 +303,32 @@ static void sh_dmae_setup_xfer(struct shdma_chan *schan,
> }
> }
>
> +/*
> + * Find a slave channel configuration from the contoller list by either a
> slave
> + * ID in the non-DT case, or by a MID/RID value in the DT case
> + */
> static const struct sh_dmae_slave_config *dmae_find_slave(
> - struct sh_dmae_chan *sh_chan, int slave_id)
> + struct sh_dmae_chan *sh_chan, int match)
> {
> struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
> struct sh_dmae_pdata *pdata = shdev->pdata;
> const struct sh_dmae_slave_config *cfg;
> int i;
>
> - if (slave_id >= SH_DMA_SLAVE_NUMBER)
> - return NULL;
> + if (!sh_chan->shdma_chan.dev->of_node) {
> + if (match >= SH_DMA_SLAVE_NUMBER)
> + return NULL;
>
> - for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
> - if (cfg->slave_id == slave_id)
> - return cfg;
> + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++,
> cfg++)
> + if (cfg->slave_id == match)
> + return cfg;
> + } else {
> + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++,
> cfg++)
> + if (cfg->mid_rid == match) {
> + sh_chan->shdma_chan.slave_id = cfg->slave_id;
> + return cfg;
> + }
> + }
>
> return NULL;
> }
> @@ -841,6 +855,14 @@ static int sh_dmae_probe(struct platform_device *pdev)
> if (err < 0)
> goto edmadevreg;
>
> + if (pdev->dev.of_node) {
> + int of_err = of_dma_controller_register(pdev->dev.of_node,
> + shdma_xlate, shdev);
> + if (of_err < 0 && of_err != -ENODEV)
> + dev_err(&pdev->dev,
> + "could not register of_dma_controller\n");
> + }
> +
> return err;
>
> edmadevreg:
> @@ -889,6 +911,9 @@ static int sh_dmae_remove(struct platform_device *pdev)
>
> dma_async_device_unregister(dma_dev);
>
> + if (pdev->dev.of_node)
> + of_dma_controller_free(pdev->dev.of_node);
> +
> if (errirq > 0)
> free_irq(errirq, shdev);
>
> @@ -920,11 +945,18 @@ static int sh_dmae_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct of_device_id sh_dmae_of_match[] = {
> + { .compatible = "renesas,shdma", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
> +
> static struct platform_driver sh_dmae_driver = {
> .driver = {
> .owner = THIS_MODULE,
> .pm = &sh_dmae_pm,
> .name = SH_DMAE_DRV_NAME,
> + .of_match_table = sh_dmae_of_match,
> },
> .remove = sh_dmae_remove,
> .shutdown = sh_dmae_shutdown,
> diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h
> index 9a93897..0815a0e 100644
> --- a/include/linux/shdma-base.h
> +++ b/include/linux/shdma-base.h
> @@ -19,6 +19,7 @@
> #include <linux/dmaengine.h>
> #include <linux/interrupt.h>
> #include <linux/list.h>
> +#include <linux/of_dma.h>
> #include <linux/types.h>
>
> /**
> @@ -68,6 +69,8 @@ struct shdma_chan {
> int id; /* Raw id of this channel */
> int irq; /* Channel IRQ */
> int slave_id; /* Client ID for slave DMA */
> + int hw_req; /* DMA request line for slave DMA - same
> + * as MID/RID, used with DT */
> enum shdma_pm_state pm_state;
> };
>
> @@ -123,5 +126,7 @@ int shdma_init(struct device *dev, struct shdma_dev *sdev,
> int chan_num);
> void shdma_cleanup(struct shdma_dev *sdev);
> bool shdma_chan_filter(struct dma_chan *chan, void *arg);
> +struct dma_chan *shdma_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma);
>
> #endif
> --
> 1.7.2.5
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
