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>

1 files changed, 102 insertions, 27 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index d1edf15b29fc..7d6ad6cd4a50 100644
--- 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,