mmc: dw_mmc: Add support for pre_req and post_req

This patch implements pre_req and post_req in dw_mmc to support
asynchronous mmc request.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index d1edf15..7d6ad6c 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -296,14 +296,24 @@ static void dw_mci_stop_dma(struct dw_mci *host)
 }
 
 #ifdef CONFIG_MMC_DW_IDMAC
+static int dw_mci_get_dma_dir(struct mmc_data *data)
+{
+       if (data->flags & MMC_DATA_WRITE)
+               return DMA_TO_DEVICE;
+       else
+               return DMA_FROM_DEVICE;
+}
+
 static void dw_mci_dma_cleanup(struct dw_mci *host)
 {
        struct mmc_data *data = host->data;
 
        if (data)
-               dma_unmap_sg(&host->dev, data->sg, data->sg_len,
-                            ((data->flags & MMC_DATA_WRITE)
-                             ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
+               if (!data->host_cookie)
+                       dma_unmap_sg(&host->dev,
+                                    data->sg,
+                                    data->sg_len,
+                                    dw_mci_get_dma_dir(data));
 }
 
 static void dw_mci_idmac_stop_dma(struct dw_mci *host)
@@ -419,26 +429,15 @@ static int dw_mci_idmac_init(struct dw_mci *host)
        return 0;
 }
 
-static struct dw_mci_dma_ops dw_mci_idmac_ops = {
-       .init = dw_mci_idmac_init,
-       .start = dw_mci_idmac_start_dma,
-       .stop = dw_mci_idmac_stop_dma,
-       .complete = dw_mci_idmac_complete_dma,
-       .cleanup = dw_mci_dma_cleanup,
-};
-#endif /* CONFIG_MMC_DW_IDMAC */
-
-static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
+static int dw_mci_pre_dma_transfer(struct dw_mci *host,
+                                  struct mmc_data *data,
+                                  bool next)
 {
        struct scatterlist *sg;
-       unsigned int i, direction, sg_len;
-       u32 temp;
-
-       host->using_dma = 0;
+       unsigned int i, sg_len;
 
-       /* If we don't have a channel, we can't do DMA */
-       if (!host->use_dma)
-               return -ENODEV;
+       if (!next && data->host_cookie)
+               return data->host_cookie;
 
        /*
         * We don't do DMA on "complex" transfers, i.e. with
@@ -447,6 +446,7 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
         */
        if (data->blocks * data->blksz < DW_MCI_DMA_THRESHOLD)
                return -EINVAL;
+
        if (data->blksz & 3)
                return -EINVAL;
 
@@ -455,15 +455,88 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
                        return -EINVAL;
        }
 
-       host->using_dma = 1;
+       sg_len = dma_map_sg(&host->dev,
+                           data->sg,
+                           data->sg_len,
+                           dw_mci_get_dma_dir(data));
+       if (sg_len == 0)
+               return -EINVAL;
 
-       if (data->flags & MMC_DATA_READ)
-               direction = DMA_FROM_DEVICE;
-       else
-               direction = DMA_TO_DEVICE;
+       if (next)
+               data->host_cookie = sg_len;
+
+       return sg_len;
+}
+
+static struct dw_mci_dma_ops dw_mci_idmac_ops = {
+       .init = dw_mci_idmac_init,
+       .start = dw_mci_idmac_start_dma,
+       .stop = dw_mci_idmac_stop_dma,
+       .complete = dw_mci_idmac_complete_dma,
+       .cleanup = dw_mci_dma_cleanup,
+};
+#else
+static int dw_mci_pre_dma_transfer(struct dw_mci *host,
+                                  struct mmc_data *data,
+                                  bool next)
+{
+       return -ENOSYS;
+}
+#endif /* CONFIG_MMC_DW_IDMAC */
+
+static void dw_mci_pre_req(struct mmc_host *mmc,
+                          struct mmc_request *mrq,
+                          bool is_first_req)
+{
+       struct dw_mci_slot *slot = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+
+       if (!slot->host->use_dma || !data)
+               return;
+
+       if (data->host_cookie) {
+               data->host_cookie = 0;
+               return;
+       }
+
+       if (dw_mci_pre_dma_transfer(slot->host, mrq->data, 1) < 0)
+               data->host_cookie = 0;
+}
+
+static void dw_mci_post_req(struct mmc_host *mmc,
+                           struct mmc_request *mrq,
+                           int err)
+{
+       struct dw_mci_slot *slot = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+
+       if (!slot->host->use_dma || !data)
+               return;
+
+       if (data->host_cookie)
+               dma_unmap_sg(&slot->host->dev,
+                            data->sg,
+                            data->sg_len,
+                            dw_mci_get_dma_dir(data));
+       data->host_cookie = 0;
+}
+
+static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
+{
+       int sg_len;
+       u32 temp;
 
-       sg_len = dma_map_sg(&host->dev, data->sg, data->sg_len,
-                           direction);
+       host->using_dma = 0;
+
+       /* If we don't have a channel, we can't do DMA */
+       if (!host->use_dma)
+               return -ENODEV;
+
+       sg_len = dw_mci_pre_dma_transfer(host, data, 0);
+       if (sg_len < 0)
+               return sg_len;
+
+       host->using_dma = 1;
 
        dev_vdbg(&host->dev,
                 "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
@@ -800,6 +873,8 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 
 static const struct mmc_host_ops dw_mci_ops = {
        .request                = dw_mci_request,
+       .pre_req                = dw_mci_pre_req,
+       .post_req               = dw_mci_post_req,
        .set_ios                = dw_mci_set_ios,
        .get_ro                 = dw_mci_get_ro,
        .get_cd                 = dw_mci_get_cd,