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authorAnatolij Gustschin <agust@denx.de>2013-04-08 23:28:09 +0200
committerChris Ball <cjb@laptop.org>2013-04-12 15:13:41 -0400
commite48fc15aa205f380b2fc6d565724a55b1efd8083 (patch)
treeea229dfbfaeeabe15f606734959eeb76f3f34c18 /drivers/mmc/host
parent42477053c389900f28e200c198830c838989809f (diff)
downloadvexpress-lsk-e48fc15aa205f380b2fc6d565724a55b1efd8083.tar.gz
mmc: mxcmmc: enable DMA support on mpc512x
Add SDHC DMA channel description to the mpc512x device tree to enable slave channel requesting in the mxcmmc driver. mpc512x DMA engine doesn't support endianness conversion when reading/writing data from peripheral's FIFO, so we have to swap data buffers before each DMA write and after each DMA read transfer manually. Since chained SDHC DMA transfers are not supported on mpc512x, limit 'max_segs' tunable parameter to one and initialise it to 64 only when running on i.MX platforms. Signed-off-by: Anatolij Gustschin <agust@denx.de> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/host')
-rw-r--r--drivers/mmc/host/mxcmmc.c35
1 files changed, 33 insertions, 2 deletions
diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 5d528269587..d5036353bdd 100644
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -301,6 +301,29 @@ static void mxcmci_softreset(struct mxcmci_host *host)
}
static int mxcmci_setup_dma(struct mmc_host *mmc);
+#if IS_ENABLED(CONFIG_PPC_MPC512x)
+static inline void buffer_swap32(u32 *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < ((len + 3) / 4); i++) {
+ st_le32(buf, *buf);
+ buf++;
+ }
+}
+
+static void mxcmci_swap_buffers(struct mmc_data *data)
+{
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(data->sg, sg, data->sg_len, i)
+ buffer_swap32(sg_virt(sg), sg->length);
+}
+#else
+static inline void mxcmci_swap_buffers(struct mmc_data *data) {}
+#endif
+
static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
{
unsigned int nob = data->blocks;
@@ -336,6 +359,8 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
} else {
host->dma_dir = DMA_TO_DEVICE;
slave_dirn = DMA_MEM_TO_DEV;
+
+ mxcmci_swap_buffers(data);
}
nents = dma_map_sg(host->dma->device->dev, data->sg,
@@ -461,9 +486,11 @@ static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
struct mmc_data *data = host->data;
int data_error;
- if (mxcmci_use_dma(host))
+ if (mxcmci_use_dma(host)) {
dma_unmap_sg(host->dma->device->dev, data->sg, data->sg_len,
host->dma_dir);
+ mxcmci_swap_buffers(data);
+ }
if (stat & STATUS_ERR_MASK) {
dev_dbg(mmc_dev(host->mmc), "request failed. status: 0x%08x\n",
@@ -1050,7 +1077,6 @@ static int mxcmci_probe(struct platform_device *pdev)
mmc->caps |= MMC_CAP_SDIO_IRQ;
/* MMC core transfer sizes tunable parameters */
- mmc->max_segs = 64;
mmc->max_blk_size = 2048;
mmc->max_blk_count = 65535;
mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
@@ -1069,6 +1095,11 @@ static int mxcmci_probe(struct platform_device *pdev)
} else {
host->devtype = pdev->id_entry->driver_data;
}
+
+ /* adjust max_segs after devtype detection */
+ if (!is_mpc512x_mmc(host))
+ mmc->max_segs = 64;
+
host->mmc = mmc;
host->pdata = pdata;
spin_lock_init(&host->lock);