ARM: OMAP2+: UART: Add wakeup mechanism for omap-uarts

From the runtime callbacks enable hwmod wakeups for uart which will
internally enable io-pad wakeups for uarts if they have rx-pad pins
set as wakeup capabale.

Use the io-ring wakeup mechanism after uart clock gating and leave
the PM_WKST set for uart to default reset values cleanup the
code in serial.c which was handling PM_WKST reg.
Irq_chaing(PRM_DRIVER) is used to wakeup uart after uart clocks are gated
using pad wakeup mechanism.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 764ac7795694..45a25a01c44d 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1496,9 +1496,24 @@ static int serial_omap_runtime_suspend(struct device *dev)
         if (!up)
                 return -EINVAL;
 
+        if (!pdata->enable_wakeup)
+                return 0;
+
         if (pdata->get_context_loss_count)
                 up->context_loss_cnt = pdata->get_context_loss_count(dev);
 
+        if (device_may_wakeup(dev)) {
+                if (!up->wakeups_enabled) {
+                        pdata->enable_wakeup(up->pdev, true);
+                        up->wakeups_enabled = true;
+                }
+        } else {
+                if (up->wakeups_enabled) {
+                        pdata->enable_wakeup(up->pdev, false);
+                        up->wakeups_enabled = false;
+                }
+        }
+
         /* Errata i291 */
         if (up->use_dma && pdata->set_forceidle &&
                         (up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))