mmc: dw_mmc: add the platdat for descriptor number.

This platdata is related with buffer size.
It's increaed the performance.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index c6deb2b..95e6ba8 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -446,7 +446,7 @@ static int dw_mci_idmac_init(struct dw_mci *host)
        int i;
 
        /* Number of descriptors in the ring buffer */
-       host->ring_size = PAGE_SIZE / sizeof(struct idmac_desc);
+       host->ring_size = host->buf_size / sizeof(struct idmac_desc);
 
        /* Forward link the descriptor list */
        for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; i++, p++)
@@ -2078,8 +2078,13 @@ static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int id)
 
 static void dw_mci_init_dma(struct dw_mci *host)
 {
+       if (host->pdata->desc_num)
+               host->buf_size = host->pdata->desc_num * PAGE_SIZE;
+       else
+               host->buf_size = PAGE_SIZE;
+
        /* Alloc memory for sg translation */
-       host->sg_cpu = dmam_alloc_coherent(host->dev, PAGE_SIZE,
+       host->sg_cpu = dmam_alloc_coherent(host->dev, host->buf_size,
                                          &host->sg_dma, GFP_KERNEL);
        if (!host->sg_cpu) {
                dev_err(host->dev, "%s: could not alloc DMA memory\n",
@@ -2185,6 +2190,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
                                "value of FIFOTH register as default\n");
 
        of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);
+       of_property_read_u32(np, "desc-num", &pdata->desc_num);
 
        if (!of_property_read_u32(np, "clock-frequency", &clock_frequency))
                pdata->bus_hz = clock_frequency;

diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 198f0fa..ae031e1 100644 (file)
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -138,6 +138,7 @@ struct dw_mci {
        dma_addr_t              sg_dma;
        void                    *sg_cpu;
        const struct dw_mci_dma_ops     *dma_ops;
+       unsigned int            buf_size;
 #ifdef CONFIG_MMC_DW_IDMAC
        unsigned int            ring_size;
 #else
@@ -241,6 +242,9 @@ struct dw_mci_board {
         */
        unsigned int fifo_depth;
 
+       /* Numer of descriptor */
+       unsigned int desc_num;
+
        /* delay in mS before detecting cards after interrupt */
        u32 detect_delay_ms;