2 files changed, 14 insertions, 5 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 5feab7db9449..ca18117def0a 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -3004,14 +3004,21 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
          * ? has revision 1
          * DB8500v1 has revision 2
          * DB8500v2 has revision 3
+         * AP9540v1 has revision 4
+         * DB8540v1 has revision 4
          */
         rev = AMBA_REV_BITS(pid);
 
+        plat_data = pdev->dev.platform_data;
+
         /* The number of physical channels on this HW */
-        num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;
+        if (plat_data->num_of_phy_chans)
+                num_phy_chans = plat_data->num_of_phy_chans;
+        else
+                num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;
 
-        dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
-                 rev, res->start);
+        dev_info(&pdev->dev, "hardware revision: %d @ 0x%x with %d physical channels\n",
+                 rev, res->start, num_phy_chans);
 
         if (rev < 2) {
                 d40_err(&pdev->dev, "hardware revision: %d is not supported",
@@ -3019,8 +3026,6 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
                 goto failure;
         }
 
-        plat_data = pdev->dev.platform_data;
-
         /* Count the number of logical channels in use */
         for (i = 0; i < plat_data->dev_len; i++)
                 if (plat_data->dev_rx[i] != 0)
diff --git a/include/linux/platform_data/dma-ste-dma40.h b/include/linux/platform_data/dma-ste-dma40.h
index 9ff93b065686..833cb959f3df 100644
--- a/include/linux/platform_data/dma-ste-dma40.h
+++ b/include/linux/platform_data/dma-ste-dma40.h
@@ -147,6 +147,9 @@ struct stedma40_chan_cfg {
  * @memcpy_conf_log: default configuration of logical channel memcpy
  * @disabled_channels: A vector, ending with -1, that marks physical channels
  * that are for different reasons not available for the driver.
+ * @num_of_phy_chans: The number of physical channels implemented in HW.
+ * 0 means reading the number of channels from DMA HW but this is only valid
+ * for 'multiple of 4' channels, like 8.
  */
 struct stedma40_platform_data {
         u32                              dev_len;
@@ -158,6 +161,7 @@ struct stedma40_platform_data {
         struct stedma40_chan_cfg        *memcpy_conf_log;
         int                              disabled_channels[STEDMA40_MAX_PHYS];
         bool                             use_esram_lcla;
+        int                              num_of_phy_chans;
 };
 
 #ifdef CONFIG_STE_DMA40