| Message ID | 20190527083150.220194-3-tientzu@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support 8250-mtk uart in-band wake up | expand |
On Mon, May 27, 2019 at 4:32 PM Claire Chang <tientzu@chromium.org> wrote: > > In order to support Rx in-band wakeup, we need to enable irq wake on an > edge sensitive interrupt of Rx pin before suspend and disable it when > resuming. > > This interrupt is used only as wake source to resume the system when > suspended. Note that the sent character will be lost as the controller is > actually suspended. > > We use this to support wakeup on bluetooth. Bluetooth will repeatedly send > 0xFD to wakeup host. Once host detects Rx falling, an interrupt is > triggered, and the system leaves sleep state. Then, the bluetooth driver > will send 0xFC to bluetooth and bluetooth can start to send normal HCI > packets. > > Signed-off-by: Claire Chang <tientzu@chromium.org> Reviewed-by: Nicolas Boichat <drinkcat@chromium.org> > --- > drivers/tty/serial/8250/8250_mtk.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c > index 417c7c810df9..5b94b853387d 100644 > --- a/drivers/tty/serial/8250/8250_mtk.c > +++ b/drivers/tty/serial/8250/8250_mtk.c > @@ -10,6 +10,7 @@ > #include <linux/module.h> > #include <linux/of_irq.h> > #include <linux/of_platform.h> > +#include <linux/pinctrl/consumer.h> > #include <linux/platform_device.h> > #include <linux/pm_runtime.h> > #include <linux/serial_8250.h> > @@ -70,6 +71,7 @@ struct mtk8250_data { > #ifdef CONFIG_SERIAL_8250_DMA > enum dma_rx_status rx_status; > #endif > + int rx_wakeup_irq; > }; > > /* flow control mode */ > @@ -551,6 +553,8 @@ static int mtk8250_probe(struct platform_device *pdev) > pm_runtime_set_active(&pdev->dev); > pm_runtime_enable(&pdev->dev); > > + data->rx_wakeup_irq = platform_get_irq(pdev, 1); > + > return 0; > } > > @@ -572,15 +576,35 @@ static int mtk8250_remove(struct platform_device *pdev) > static int __maybe_unused mtk8250_suspend(struct device *dev) > { > struct mtk8250_data *data = dev_get_drvdata(dev); > + int irq = data->rx_wakeup_irq; > + int err; > > serial8250_suspend_port(data->line); > > + pinctrl_pm_select_sleep_state(dev); > + if (irq >= 0) { > + err = enable_irq_wake(irq); > + if (err) { > + dev_err(dev, > + "failed to enable irq wake on IRQ %d: %d\n", > + irq, err); > + pinctrl_pm_select_default_state(dev); > + serial8250_resume_port(data->line); > + return err; > + } > + } > + > return 0; > } > > static int __maybe_unused mtk8250_resume(struct device *dev) > { > struct mtk8250_data *data = dev_get_drvdata(dev); > + int irq = data->rx_wakeup_irq; > + > + if (irq >= 0) > + disable_irq_wake(irq); > + pinctrl_pm_select_default_state(dev); > > serial8250_resume_port(data->line); > > -- > 2.22.0.rc1.257.g3120a18244-goog >
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index 417c7c810df9..5b94b853387d 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -10,6 +10,7 @@ #include <linux/module.h> #include <linux/of_irq.h> #include <linux/of_platform.h> +#include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/serial_8250.h> @@ -70,6 +71,7 @@ struct mtk8250_data { #ifdef CONFIG_SERIAL_8250_DMA enum dma_rx_status rx_status; #endif + int rx_wakeup_irq; }; /* flow control mode */ @@ -551,6 +553,8 @@ static int mtk8250_probe(struct platform_device *pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); + data->rx_wakeup_irq = platform_get_irq(pdev, 1); + return 0; } @@ -572,15 +576,35 @@ static int mtk8250_remove(struct platform_device *pdev) static int __maybe_unused mtk8250_suspend(struct device *dev) { struct mtk8250_data *data = dev_get_drvdata(dev); + int irq = data->rx_wakeup_irq; + int err; serial8250_suspend_port(data->line); + pinctrl_pm_select_sleep_state(dev); + if (irq >= 0) { + err = enable_irq_wake(irq); + if (err) { + dev_err(dev, + "failed to enable irq wake on IRQ %d: %d\n", + irq, err); + pinctrl_pm_select_default_state(dev); + serial8250_resume_port(data->line); + return err; + } + } + return 0; } static int __maybe_unused mtk8250_resume(struct device *dev) { struct mtk8250_data *data = dev_get_drvdata(dev); + int irq = data->rx_wakeup_irq; + + if (irq >= 0) + disable_irq_wake(irq); + pinctrl_pm_select_default_state(dev); serial8250_resume_port(data->line);
In order to support Rx in-band wakeup, we need to enable irq wake on an edge sensitive interrupt of Rx pin before suspend and disable it when resuming. This interrupt is used only as wake source to resume the system when suspended. Note that the sent character will be lost as the controller is actually suspended. We use this to support wakeup on bluetooth. Bluetooth will repeatedly send 0xFD to wakeup host. Once host detects Rx falling, an interrupt is triggered, and the system leaves sleep state. Then, the bluetooth driver will send 0xFC to bluetooth and bluetooth can start to send normal HCI packets. Signed-off-by: Claire Chang <tientzu@chromium.org> --- drivers/tty/serial/8250/8250_mtk.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)