After the latest changes to atmel-mci, it could not be used with
DMA on the AVR32 platform. This patch will allow to use DMA again
and it will avoid access to MCI register ATMCI_DMA.

v2:
Even if the IP version is lower than v3xx and doesn't have the DMA
configuration register, DMA transfers can be used with a different
controller than the Atmel AHB DMA one. For instance, some AVR chips use 
the Synopsys DesignWare AHB DMA controller.

v2: in atmci_configure_dma: check both pdata and pdata->dma_slave


Signed-off-by: Hein Tibosch <hein_tibo...@yahoo.es>
Acked-by: Ludovic Desroches <ludovic.desroc...@atmel.com>
---
 drivers/mmc/host/atmel-mci.c |   26 +++++++++++++-------------
 1 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index f2c115e..a6a5593 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -71,7 +71,7 @@ enum atmci_pdc_buf {
 };
 
 struct atmel_mci_caps {
-       bool    has_dma;
+       bool    has_dma_conf_reg;
        bool    has_pdc;
        bool    has_cfg_reg;
        bool    has_cstor_reg;
@@ -411,7 +411,7 @@ static int atmci_regs_show(struct seq_file *s, void *v)
        atmci_show_status_reg(s, "SR", buf[ATMCI_SR / 4]);
        atmci_show_status_reg(s, "IMR", buf[ATMCI_IMR / 4]);
 
-       if (host->caps.has_dma) {
+       if (host->caps.has_dma_conf_reg) {
                u32 val;
 
                val = buf[ATMCI_DMA / 4];
@@ -767,7 +767,7 @@ static void atmci_dma_complete(void *arg)
 
        dev_vdbg(&host->pdev->dev, "DMA complete\n");
 
-       if (host->caps.has_dma)
+       if (host->caps.has_dma_conf_reg)
                /* Disable DMA hardware handshaking on MCI */
                atmci_writel(host, ATMCI_DMA, atmci_readl(host, ATMCI_DMA) & 
~ATMCI_DMAEN);
 
@@ -954,7 +954,9 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct 
mmc_data *data)
                maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst);
        }
 
-       atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | 
ATMCI_DMAEN);
+       if (host->caps.has_dma_conf_reg)
+               atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) |
+                       ATMCI_DMAEN);
 
        sglen = dma_map_sg(chan->device->dev, data->sg,
                        data->sg_len, direction);
@@ -2161,7 +2163,10 @@ static bool atmci_configure_dma(struct atmel_mci *host)
 
        pdata = host->pdev->dev.platform_data;
 
-       if (pdata && find_slave_dev(pdata->dma_slave)) {
+       if (!pdata)
+               return false;
+
+       if (pdata->dma_slave && find_slave_dev(pdata->dma_slave)) {
                dma_cap_mask_t mask;
 
                /* Try to grab a DMA channel */
@@ -2202,7 +2207,7 @@ static void __init atmci_get_cap(struct atmel_mci *host)
        dev_info(&host->pdev->dev,
                        "version: 0x%x\n", version);
 
-       host->caps.has_dma = 0;
+       host->caps.has_dma_conf_reg = 0;
        host->caps.has_pdc = 1;
        host->caps.has_cfg_reg = 0;
        host->caps.has_cstor_reg = 0;
@@ -2219,12 +2224,7 @@ static void __init atmci_get_cap(struct atmel_mci *host)
                host->caps.has_odd_clk_div = 1;
        case 0x400:
        case 0x300:
-#ifdef CONFIG_AT_HDMAC
-               host->caps.has_dma = 1;
-#else
-               dev_info(&host->pdev->dev,
-                       "has dma capability but dma engine is not selected, 
then use pio\n");
-#endif
+               host->caps.has_dma_conf_reg = 1;
                host->caps.has_pdc = 0;
                host->caps.has_cfg_reg = 1;
                host->caps.has_cstor_reg = 1;
@@ -2298,7 +2298,7 @@ static int __init atmci_probe(struct platform_device 
*pdev)
 
        /* Get MCI capabilities and set operations according to it */
        atmci_get_cap(host);
-       if (host->caps.has_dma && atmci_configure_dma(host)) {
+       if (atmci_configure_dma(host)) {
                host->prepare_data = &atmci_prepare_data_dma;
                host->submit_data = &atmci_submit_data_dma;
                host->stop_transfer = &atmci_stop_transfer_dma;
-- 
1.7.8.0

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