[PATCH v2] dma: dw: Add suspend and resume handling for PCI mode DW_DMAC.

Chew Chiau Ee
2014-03-14T10:00:48Z

From: Chew, Chiau Ee <chiau.ee.chew@intel.com>

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>
---
v2 changelog:
* Change suspend_noirq and resume_noirq callback to suspend_late
and resume_early.

drivers/dma/dw/pci.c | 33 +++++++++++++++++++++++++++++++++
1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/dw/pci.c b/drivers/dma/dw/pci.c
index 755cc6b..fec59f1 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);
--
1.7.4.4