atmel-mci: change use of dma slave interface

Allow the use of another DMA controller driver in atmel-mci sd/mmc driver.
 This adds a generic dma_slave pointer to the mci platform structure where
we can store DMA controller information.  In atmel-mci we use information
provided by this structure to initialize the driver (with new helper
functions that are architecture dependant).

This also adds at32/avr32 chip modifications to cope with this new access
method.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 98 insertions, 28 deletions

diff --git a/arch/arm/mach-at91/include/mach/atmel-mci.h b/arch/arm/mach-at91/include/mach/atmel-mci.h
new file mode 100644
index 000000000000..998cb0c07135
--- /dev/null
+++ b/arch/arm/mach-at91/include/mach/atmel-mci.h
@@ -0,0 +1,24 @@
+#ifndef __MACH_ATMEL_MCI_H
+#define __MACH_ATMEL_MCI_H
+
+#include <mach/at_hdmac.h>
+
+/**
+ * struct mci_dma_data - DMA data for MCI interface
+ */
+struct mci_dma_data {
+        struct at_dma_slave     sdata;
+};
+
+/* accessor macros */
+#define slave_data_ptr(s)       (&(s)->sdata)
+#define find_slave_dev(s)       ((s)->sdata.dma_dev)
+
+#define setup_dma_addr(s, t, r) do {            \
+        if (s) {                                \
+                (s)->sdata.tx_reg = (t);        \
+                (s)->sdata.rx_reg = (r);        \
+        }                                       \
+} while (0)
+
+#endif /* __MACH_ATMEL_MCI_H */
diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index eb9d4dc2e86d..b40ff39e0ac8 100644
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -15,6 +15,8 @@
 #include <linux/gpio.h>
 #include <linux/spi/spi.h>
 #include <linux/usb/atmel_usba_udc.h>
+
+#include <mach/atmel-mci.h>
 #include <linux/atmel-mci.h>
 
 #include <asm/io.h>
@@ -1320,7 +1322,7 @@ struct platform_device *__init
 at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
 {
         struct platform_device          *pdev;
-        struct dw_dma_slave             *dws = &data->dma_slave;
+        struct mci_dma_slave            *slave;
         u32                             pioa_mask;
         u32                             piob_mask;
 
@@ -1339,13 +1341,17 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
                                 ARRAY_SIZE(atmel_mci0_resource)))
                 goto fail;
 
-        dws->dma_dev = &dw_dmac0_device.dev;
-        dws->reg_width = DW_DMA_SLAVE_WIDTH_32BIT;
-        dws->cfg_hi = (DWC_CFGH_SRC_PER(0)
+        slave = kzalloc(sizeof(struct mci_dma_slave), GFP_KERNEL);
+
+        slave->sdata.dma_dev = &dw_dmac0_device.dev;
+        slave->sdata.reg_width = DW_DMA_SLAVE_WIDTH_32BIT;
+        slave->sdata.cfg_hi = (DWC_CFGH_SRC_PER(0)
                                 | DWC_CFGH_DST_PER(1));
-        dws->cfg_lo &= ~(DWC_CFGL_HS_DST_POL
+        slave->sdata.cfg_lo &= ~(DWC_CFGL_HS_DST_POL
                                 | DWC_CFGL_HS_SRC_POL);
 
+        data->dma_slave = slave;
+
         if (platform_device_add_data(pdev, data,
                                 sizeof(struct mci_platform_data)))
                 goto fail;
@@ -1411,6 +1417,8 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
         return pdev;
 
 fail:
+        data->dma_slave = NULL;
+        kfree(slave);
         platform_device_put(pdev);
         return NULL;
 }
diff --git a/arch/avr32/mach-at32ap/include/mach/atmel-mci.h b/arch/avr32/mach-at32ap/include/mach/atmel-mci.h
new file mode 100644
index 000000000000..a9b38967f703
--- /dev/null
+++ b/arch/avr32/mach-at32ap/include/mach/atmel-mci.h
@@ -0,0 +1,24 @@
+#ifndef __MACH_ATMEL_MCI_H
+#define __MACH_ATMEL_MCI_H
+
+#include <linux/dw_dmac.h>
+
+/**
+ * struct mci_dma_data - DMA data for MCI interface
+ */
+struct mci_dma_data {
+        struct dw_dma_slave     sdata;
+};
+
+/* accessor macros */
+#define slave_data_ptr(s)       (&(s)->sdata)
+#define find_slave_dev(s)       ((s)->sdata.dma_dev)
+
+#define setup_dma_addr(s, t, r) do {            \
+        if (s) {                                \
+                (s)->sdata.tx_reg = (t);        \
+                (s)->sdata.rx_reg = (r);        \
+        }                                       \
+} while (0)
+
+#endif /* __MACH_ATMEL_MCI_H */
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index fc25586b7ee1..ba8b219d44c1 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -25,6 +25,8 @@
 #include <linux/stat.h>
 
 #include <linux/mmc/host.h>
+
+#include <mach/atmel-mci.h>
 #include <linux/atmel-mci.h>
 
 #include <asm/io.h>
@@ -1584,14 +1586,43 @@ static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
 #ifdef CONFIG_MMC_ATMELMCI_DMA
 static bool filter(struct dma_chan *chan, void *slave)
 {
-        struct dw_dma_slave *dws = slave;
+        struct mci_dma_data     *sl = slave;
 
-        if (dws->dma_dev == chan->device->dev) {
-                chan->private = dws;
+        if (sl && find_slave_dev(sl) == chan->device->dev) {
+                chan->private = slave_data_ptr(sl);
                 return true;
-        } else
+        } else {
                 return false;
+        }
 }
+
+static void atmci_configure_dma(struct atmel_mci *host)
+{
+        struct mci_platform_data        *pdata;
+
+        if (host == NULL)
+                return;
+
+        pdata = host->pdev->dev.platform_data;
+
+        if (pdata && find_slave_dev(pdata->dma_slave)) {
+                dma_cap_mask_t mask;
+
+                setup_dma_addr(pdata->dma_slave,
+                               host->mapbase + MCI_TDR,
+                               host->mapbase + MCI_RDR);
+
+                /* Try to grab a DMA channel */
+                dma_cap_zero(mask);
+                dma_cap_set(DMA_SLAVE, mask);
+                host->dma.chan =
+                        dma_request_channel(mask, filter, pdata->dma_slave);
+        }
+        if (!host->dma.chan)
+                dev_notice(&host->pdev->dev, "DMA not available, using PIO\n");
+}
+#else
+static void atmci_configure_dma(struct atmel_mci *host) {}
 #endif
 
 static int __init atmci_probe(struct platform_device *pdev)
@@ -1645,22 +1676,7 @@ static int __init atmci_probe(struct platform_device *pdev)
         if (ret)
                 goto err_request_irq;
 
-#ifdef CONFIG_MMC_ATMELMCI_DMA
-        if (pdata->dma_slave.dma_dev) {
-                struct dw_dma_slave *dws = &pdata->dma_slave;
-                dma_cap_mask_t mask;
-
-                dws->tx_reg = regs->start + MCI_TDR;
-                dws->rx_reg = regs->start + MCI_RDR;
-
-                /* Try to grab a DMA channel */
-                dma_cap_zero(mask);
-                dma_cap_set(DMA_SLAVE, mask);
-                host->dma.chan = dma_request_channel(mask, filter, dws);
-        }
-        if (!host->dma.chan)
-                dev_notice(&pdev->dev, "DMA not available, using PIO\n");
-#endif /* CONFIG_MMC_ATMELMCI_DMA */
+        atmci_configure_dma(host);
 
         platform_set_drvdata(pdev, host);
 
diff --git a/include/linux/atmel-mci.h b/include/linux/atmel-mci.h
index 57b1846a3c87..3e09b345f4d6 100644
--- a/include/linux/atmel-mci.h
+++ b/include/linux/atmel-mci.h
@@ -3,8 +3,6 @@
 
 #define ATMEL_MCI_MAX_NR_SLOTS  2
 
-#include <linux/dw_dmac.h>
-
 /**
  * struct mci_slot_pdata - board-specific per-slot configuration
  * @bus_width: Number of data lines wired up the slot
@@ -34,7 +32,7 @@ struct mci_slot_pdata {
  * @slot: Per-slot configuration data.
  */
 struct mci_platform_data {
-        struct dw_dma_slave     dma_slave;
+        struct mci_dma_data     *dma_slave;
         struct mci_slot_pdata   slot[ATMEL_MCI_MAX_NR_SLOTS];
 };