dma: dw: Add suspend and resume handling for PCI mode DW_DMAC.

This is to disable/enable DW_DMAC hw during late suspend/early resume.
Since DMA is providing service to other clients (eg: SPI, HSUART),
we need to ensure DMA suspends after the clients and resume
before the clients are active.

Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/dma/dw/pci.c b/drivers/dma/dw/pci.c
index 755cc6b54453..fec59f1a77bb 100644
--- a/drivers/dma/dw/pci.c
+++ b/drivers/dma/dw/pci.c
@@ -75,6 +75,36 @@ static void dw_pci_remove(struct pci_dev *pdev)
                 dev_warn(&pdev->dev, "can't remove device properly: %d\n", ret);
 }
 
+#ifdef CONFIG_PM_SLEEP
+
+static int dw_pci_suspend_late(struct device *dev)
+{
+        struct pci_dev *pci = to_pci_dev(dev);
+        struct dw_dma_chip *chip = pci_get_drvdata(pci);
+
+        return dw_dma_suspend(chip);
+};
+
+static int dw_pci_resume_early(struct device *dev)
+{
+        struct pci_dev *pci = to_pci_dev(dev);
+        struct dw_dma_chip *chip = pci_get_drvdata(pci);
+
+        return dw_dma_resume(chip);
+};
+
+#else /* !CONFIG_PM_SLEEP */
+
+#define dw_pci_suspend_late     NULL
+#define dw_pci_resume_early     NULL
+
+#endif /* !CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops dw_pci_dev_pm_ops = {
+        .suspend_late = dw_pci_suspend_late,
+        .resume_early = dw_pci_resume_early,
+};
+
 static DEFINE_PCI_DEVICE_TABLE(dw_pci_id_table) = {
         /* Medfield */
         { PCI_VDEVICE(INTEL, 0x0827), (kernel_ulong_t)&dw_pci_pdata },
@@ -95,6 +125,9 @@ static struct pci_driver dw_pci_driver = {
         .id_table       = dw_pci_id_table,
         .probe          = dw_pci_probe,
         .remove         = dw_pci_remove,
+        .driver = {
+                .pm     = &dw_pci_dev_pm_ops,
+        },
 };
 
 module_pci_driver(dw_pci_driver);