Allow UART to be a source for wakeup from low power mode.
Tested on a MX27PDK by doing:
echo enabled > /sys/devices/platform/imx21-uart.0/tty/ttymxc0/power/wakeup
echo mem > /sys/power/state
and then pressing a key in the console will wakeup the sytem.
Suggested-by: Shawn Guo <shawn.guo@xxxxxxxxxxxxx>
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
---
Changes since v4:
- Let serial core handle device_init_wakeup/device_set_wakeup_enable.
Changes since v3:
- Remove IMXUART_CANWAKE flag. Let userspace write in /sys/ file
in order to enable UART wakeup source.
Changes since v2:
- Remove incorrect enable_irq_wake from serial_imx_resume
Changes since v1:
- Pass the can-wake property via DT correctly
drivers/tty/serial/imx.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 163fc90..0022bbd 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -566,6 +566,9 @@ static irqreturn_t imx_int(int irq, void *dev_id)
if (sts & USR1_RTSD)
imx_rtsint(irq, dev_id);
+ if (sts & USR1_AWAKE)
+ writel(USR1_AWAKE, sport->port.membase + USR1);
+
return IRQ_HANDLED;
}
@@ -1269,6 +1272,12 @@ static struct uart_driver imx_reg = {
static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
{
struct imx_port *sport = platform_get_drvdata(dev);
+ unsigned int val;
+
+ /* enable wakeup from i.MX UART */
+ val = readl(sport->port.membase + UCR3);
+ val |= UCR3_AWAKEN;
+ writel(val, sport->port.membase + UCR3);
if (sport)
uart_suspend_port(&imx_reg, &sport->port);
@@ -1279,7 +1288,13 @@ static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
static int serial_imx_resume(struct platform_device *dev)
{
struct imx_port *sport = platform_get_drvdata(dev);
+ unsigned int val;
+ /* disable wakeup from i.MX UART */
+ val = readl(sport->port.membase + UCR3);
+ val &= ~UCR3_AWAKEN;
+ writel(val, sport->port.membase + UCR3);
+
if (sport)
uart_resume_port(&imx_reg, &sport->port);
--
1.7.1
--
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