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

[Akash Asthana <akashast@codeaurora.org>]

On 11/23/2019 12:41 AM, Matthias Kaehlcke wrote:
> 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'.
ok
>
>> +	 * 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>

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