[PATCH] dmaengine: xgene-dma: Add ACPI support for X-Gene DMA engine driver

[Rameshwar Prasad Sahu]

This patch adds ACPI support for the APM X-Gene DMA engine driver.

Signed-off-by: Rameshwar Prasad Sahu <rs...@apm.com>
---
 drivers/dma/xgene-dma.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
index dff22ab..d0a148d 100644
--- a/drivers/dma/xgene-dma.c
+++ b/drivers/dma/xgene-dma.c
@@ -21,6 +21,7 @@
  * NOTE: PM support is currently not available.
  */

+#include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
@@ -1944,16 +1945,18 @@ static int xgene_dma_probe(struct platform_device *pdev)
                return ret;

        pdma->clk = devm_clk_get(&pdev->dev, NULL);
-       if (IS_ERR(pdma->clk)) {
+       if (IS_ERR(pdma->clk) && !ACPI_COMPANION(&pdev->dev)) {
                dev_err(&pdev->dev, "Failed to get clk\n");
                return PTR_ERR(pdma->clk);
        }

        /* Enable clk before accessing registers */
-       ret = clk_prepare_enable(pdma->clk);
-       if (ret) {
-               dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
-               return ret;
+       if (!IS_ERR(pdma->clk)) {
+               ret = clk_prepare_enable(pdma->clk);
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to enable clk %d\n", ret);
+                       return ret;
+               }
        }

        /* Remove DMA RAM out of shutdown */
@@ -1998,7 +2001,8 @@ err_request_irq:

 err_dma_mask:
 err_clk_enable:
-       clk_disable_unprepare(pdma->clk);
+       if (!IS_ERR(pdma->clk))
+               clk_disable_unprepare(pdma->clk);

        return ret;
 }
@@ -2022,11 +2026,20 @@ static int xgene_dma_remove(struct platform_device 
*pdev)
                xgene_dma_delete_chan_rings(chan);
        }

-       clk_disable_unprepare(pdma->clk);
+       if (!IS_ERR(pdma->clk))
+               clk_disable_unprepare(pdma->clk);

        return 0;
 }

+#ifdef CONFIG_ACPI
+static const struct acpi_device_id xgene_dma_acpi_match_ptr[] = {
+       {"APMC0D43", 0},
+       {},
+};
+MODULE_DEVICE_TABLE(acpi, xgene_dma_acpi_match_ptr);
+#endif
+
 static const struct of_device_id xgene_dma_of_match_ptr[] = {
        {.compatible = "apm,xgene-storm-dma",},
        {},
@@ -2039,6 +2052,7 @@ static struct platform_driver xgene_dma_driver = {
        .driver = {
                .name = "X-Gene-DMA",
                .of_match_table = xgene_dma_of_match_ptr,
+               .acpi_match_table = ACPI_PTR(xgene_dma_acpi_match_ptr),
        },
 };

--
1.8.2.1
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