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Subject[PATCH 1/2] mmc: atmel-mci: restore dma on AVR32
Date
Commit ecb89f2f5f3e7 ("mmc: atmel-mci: remove compat for non DT board
when requesting dma chan") broke dma on AVR32 and any other boards not
using DT. This restores a fallback mechanism for such cases.

Signed-off-by: Mans Rullgard <mans@mansr.com>
---
arch/avr32/mach-at32ap/at32ap700x.c | 16 ++++++++++++++++
drivers/mmc/host/atmel-mci.c | 17 +++++++++++++++++
include/linux/atmel-mci.h | 2 ++
3 files changed, 35 insertions(+)

diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index c425a5564c27..f433c7220fff 100644
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -1338,6 +1338,21 @@ static struct clk atmel_mci0_pclk = {
.index = 9,
};

+static bool at32_mci_dma_filter(struct dma_chan *chan, void *pdata)
+{
+ struct mci_dma_data *sl = pdata;
+
+ if (!sl)
+ return false;
+
+ if (find_slave_dev(sl) == chan->device->dev) {
+ chan->private = slave_data_ptr(sl);
+ return true;
+ }
+
+ return false;
+}
+
struct platform_device *__init
at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
{
@@ -1372,6 +1387,7 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
slave->sdata.p_master = 0;

data->dma_slave = slave;
+ data->dma_filter = at32_mci_dma_filter;

if (platform_device_add_data(pdev, data,
sizeof(struct mci_platform_data)))
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index bf62e429f7fc..070dffc4699e 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2280,6 +2280,23 @@ static int atmci_configure_dma(struct atmel_mci *host)
{
host->dma.chan = dma_request_slave_channel_reason(&host->pdev->dev,
"rxtx");
+
+ if (PTR_ERR(host->dma.chan) == -ENODEV) {
+ struct mci_platform_data *pdata = host->pdev->dev.platform_data;
+ dma_cap_mask_t mask;
+
+ if (!pdata->dma_filter)
+ return -ENODEV;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ host->dma.chan = dma_request_channel(mask, pdata->dma_filter,
+ pdata->dma_slave);
+ if (!host->dma.chan)
+ host->dma.chan = ERR_PTR(-ENODEV);
+ }
+
if (IS_ERR(host->dma.chan))
return PTR_ERR(host->dma.chan);

diff --git a/include/linux/atmel-mci.h b/include/linux/atmel-mci.h
index 9177947bf032..e753062b9355 100644
--- a/include/linux/atmel-mci.h
+++ b/include/linux/atmel-mci.h
@@ -2,6 +2,7 @@
#define __LINUX_ATMEL_MCI_H

#include <linux/types.h>
+#include <linux/dmaengine.h>

#define ATMCI_MAX_NR_SLOTS 2

@@ -37,6 +38,7 @@ struct mci_slot_pdata {
*/
struct mci_platform_data {
struct mci_dma_data *dma_slave;
+ dma_filter_fn dma_filter;
struct mci_slot_pdata slot[ATMCI_MAX_NR_SLOTS];
};

--
2.7.0
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