dmaengine: ste_dma40: physical channels number correction

DMAC_ICFG[0:2]=SCHNB only allows to count 'multiple of 4' physical
channels so it was ok with platforms having 8 channels but cannot be
used for next versions (with 10 or 14 channels).  This patch allows to
provide the number of physical channels for a DMA device via
platform_data, or still rely on SCHNB if platform_data announces 0
channel.

Signed-off-by: Gerald Baeza <gerald.baeza@stericsson.com>
Reviewed-by: Per Forlin <per.forlin@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 5feab7db94498a72c35b79eda2deeda00e3d464f..ca18117def0ab90bb45ec7ff581ca656b18c3421 100644 (file)
--- 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 9ff93b06568695f04822dd066f5c78a35beca3e7..833cb959f3df5a3bfaa95cfd456f5ecc9f872b28 100644 (file)
--- 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