Re: [PATCH v6 4/5] tty: serial: qcom_geni_serial: Wakeup over UART RX

[Matthias Kaehlcke <mka@chromium.org>]

On Fri, Nov 22, 2019 at 02:18:19PM +0000, Akash Asthana wrote:
> Add system wakeup capability over UART RX line for wakeup capable UART.
> When system is suspended, RX line act as an interrupt to wakeup system
> for any communication requests from peer.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
> Changes in V6:
>  - Rebased on top of tty-next branch.
>  - As per stephen's comment mark devices runtime status as active
>    irrespective of wakeup feature.
> 
> Changes in V5:
>  - No change.
> 
> Changes in V4:
>  - As per Greg's comment, removed extra dev_err logging.
>  - As per Stephen's comment, using common code that manage wakeirq irqs for
>    devices. Using dev_pm_set_dedicated_wake_irq API that will take care of
>    requesting and attaching wakeup irqs for devices. Also, it sets wakeirq
>    status to WAKE_IRQ_DEDICATED_ALLOCATED as a result enabling/disabling of
>    wake irq will be managed by suspend/resume framework so, removed the code
>    for enabling and disabling of wake irq from the driver.
> 
> Changes in V3:
>  - As per Stephen's comment, using platform_get_irq_optional API to get wakeup
>    IRQ for device.
> 
> Changes in V2:
>  - As per Stephen's comment, splitted V1 patch into 2 seperate patch.
>    a) Clean up of core IRQ registration b) Add wakeup feature.
> 
>  drivers/tty/serial/qcom_geni_serial.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 634054a..b952509 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -14,6 +14,8 @@
>  #include <linux/of.h>
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm_wakeirq.h>
>  #include <linux/qcom-geni-se.h>
>  #include <linux/serial.h>
>  #include <linux/serial_core.h>
> @@ -116,6 +118,7 @@ struct qcom_geni_serial_port {
>  	bool brk;
>  
>  	unsigned int tx_remaining;
> +	int wakeup_irq;
>  };
>  
>  static const struct uart_ops qcom_geni_console_pops;
> @@ -1302,6 +1305,9 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
>  		return irq;
>  	uport->irq = irq;
>  
> +	if (!console)
> +		port->wakeup_irq = platform_get_irq_optional(pdev, 1);
> +
>  	uport->private_data = drv;
>  	platform_set_drvdata(pdev, port);
>  	port->handle_rx = console ? handle_rx_console : handle_rx_uart;
> @@ -1321,6 +1327,24 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	/*
> +	 * Set pm_runtime status as ACTIVE so that wakeup_irq gets
> +	 * enabled/disabled from dev_pm_arm_wake_irq  during  system

nit: remove one of the two blanks before/after 'during'.

> +	 * suspend/resume respectively.
> +	 */
> +	pm_runtime_set_active(&pdev->dev);
> +
> +	if (port->wakeup_irq > 0) {
> +		device_init_wakeup(&pdev->dev, true);
> +		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
> +						port->wakeup_irq);
> +		if (ret) {
> +			device_init_wakeup(&pdev->dev, false);
> +			uart_remove_one_port(drv, uport);
> +			return ret;
> +		}
> +	}
> +
>  	return ret;
>  }
>  
> @@ -1330,6 +1354,10 @@ static int qcom_geni_serial_remove(struct platform_device *pdev)
>  	struct uart_driver *drv = port->uport.private_data;
>  
>  	uart_remove_one_port(drv, &port->uport);
> +
> +	device_init_wakeup(&pdev->dev, false);
> +	dev_pm_clear_wake_irq(&pdev->dev);
> +
>  	return 0;
>  }

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>