[RFC v02 10/15] mmc: davinci_mmc: Use dma_request_chan() to requesting DMA channel

Peter Ujfalusi
2015-11-30T13:45:40Z

With the new dma_request_chan() the clinet driver does not need to look for
the DMA resource and it does not need to pass filter_fn anymore.
By switching to the new API the davinci_mmc driver can now support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
drivers/mmc/host/davinci_mmc.c | 52 ++++++++++++------------------------------
1 file changed, 14 insertions(+), 38 deletions(-)

diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index ea2a2ebc6b91..8a0a2c291e0c 100644
--- a/drivers/mmc/host/davinci_mmc.c
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -32,12 +32,10 @@
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
-#include <linux/edma.h>
#include <linux/mmc/mmc.h>
#include <linux/of.h>
#include <linux/of_device.h>

-#include <linux/platform_data/edma.h>
#include <linux/platform_data/mmc-davinci.h>

/*
@@ -517,35 +515,20 @@ davinci_release_dma_channels(struct mmc_davinci_host *host)

static int __init davinci_acquire_dma_channels(struct mmc_davinci_host *host)
{
- int r;
- dma_cap_mask_t mask;
-
- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
-
- host->dma_tx =
- dma_request_slave_channel_compat(mask, edma_filter_fn,
- &host->txdma, mmc_dev(host->mmc), "tx");
- if (!host->dma_tx) {
+ host->dma_tx = dma_request_chan(mmc_dev(host->mmc), "tx");
+ if (IS_ERR(host->dma_tx)) {
dev_err(mmc_dev(host->mmc), "Can't get dma_tx channel\n");
- return -ENODEV;
+ return PTR_ERR(host->dma_tx);
}

- host->dma_rx =
- dma_request_slave_channel_compat(mask, edma_filter_fn,
- &host->rxdma, mmc_dev(host->mmc), "rx");
- if (!host->dma_rx) {
+ host->dma_rx = dma_request_chan(mmc_dev(host->mmc), "rx");
+ if (IS_ERR(host->dma_rx)) {
dev_err(mmc_dev(host->mmc), "Can't get dma_rx channel\n");
- r = -ENODEV;
- goto free_master_write;
+ dma_release_channel(host->dma_tx);
+ return PTR_ERR(host->dma_rx);
}

return 0;
-
-free_master_write:
- dma_release_channel(host->dma_tx);
-
- return r;
}

/*----------------------------------------------------------------------*/
@@ -1262,18 +1245,6 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
host = mmc_priv(mmc);
host->mmc = mmc; /* Important */

- r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
- if (!r)
- dev_warn(&pdev->dev, "RX DMA resource not specified\n");
- else
- host->rxdma = r->start;
-
- r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
- if (!r)
- dev_warn(&pdev->dev, "TX DMA resource not specified\n");
- else
- host->txdma = r->start;
-
host->mem_res = mem;
host->base = ioremap(mem->start, mem_size);
if (!host->base)
@@ -1300,8 +1271,13 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
host->mmc_irq = irq;
host->sdio_irq = platform_get_irq(pdev, 1);

- if (host->use_dma && davinci_acquire_dma_channels(host) != 0)
- host->use_dma = 0;
+ if (host->use_dma) {
+ ret = davinci_acquire_dma_channels(host);
+ if (ret == -EPROBE_DEFER)
+ goto out;
+ else if (ret)
+ host->use_dma = 0;
+ }

/* REVISIT: someday, support IRQ-driven card detection. */
mmc->caps |= MMC_CAP_NEEDS_POLL;
--
2.6.3