Re: [PATCH 6/6] driver: soc: xilinx: register for power events in zynqmp power driver

[Michal Simek <michal.simek@xilinx.com>]

On 5/28/21 5:59 PM, Abhyuday Godhasara wrote:
> With Xilinx Event Management driver, all types of events like power and
> error gets handled from single place as part of event management driver.
> 
> So power events(SUSPEND_POWER_REQUEST and SUSPEND_SYSTEM_SHUTDOWN)
> also gets handled by event management driver instead of zynqmp_power
> driver.
> 
> zynqmp-power driver use event management driver and provide callback
> function for Suspend and shutdown handler, which will be called by event
> management driver when respective event is arrived.
> 
> If event management driver is not available than use ipi-mailbox rx channel
> or IPI interrupt IRQ handler for power events (suspend/shutdown) same as
> current zynqmp-power driver.
> 
> Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
> Signed-off-by: Abhyuday Godhasara <abhyuday.godhasara@xilinx.com>
> ---
>  drivers/soc/xilinx/zynqmp_power.c | 48 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
> index 76478fe..fe7be17 100644
> --- a/drivers/soc/xilinx/zynqmp_power.c
> +++ b/drivers/soc/xilinx/zynqmp_power.c
> @@ -16,6 +16,7 @@
>  #include <linux/suspend.h>
>  
>  #include <linux/firmware/xlnx-zynqmp.h>
> +#include <linux/firmware/xlnx-event-manager.h>
>  #include <linux/mailbox/zynqmp-ipi-message.h>
>  
>  /**
> @@ -30,6 +31,7 @@ struct zynqmp_pm_work_struct {
>  
>  static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
>  static struct mbox_chan *rx_chan;
> +static bool event_registered;
>  
>  enum pm_suspend_mode {
>  	PM_SUSPEND_MODE_FIRST = 0,
> @@ -51,6 +53,19 @@ static void zynqmp_pm_get_callback_data(u32 *buf)
>  	zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
>  }
>  
> +static void suspend_event_callback(const u32 *payload, void *data)
> +{
> +	/* First element is callback API ID, others are callback arguments */
> +	if (work_pending(&zynqmp_pm_init_suspend_work->callback_work))
> +		return;
> +
> +	/* Copy callback arguments into work's structure */
> +	memcpy(zynqmp_pm_init_suspend_work->args, &payload[1],
> +	       sizeof(zynqmp_pm_init_suspend_work->args));
> +
> +	queue_work(system_unbound_wq, &zynqmp_pm_init_suspend_work->callback_work);
> +}
> +
>  static irqreturn_t zynqmp_pm_isr(int irq, void *data)
>  {
>  	u32 payload[CB_PAYLOAD_SIZE];
> @@ -179,7 +194,32 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>  	if (pm_api_version < ZYNQMP_PM_VERSION)
>  		return -ENODEV;
>  
> -	if (of_find_property(pdev->dev.of_node, "mboxes", NULL)) {
> +	/*
> +	 * First try to use Xilinx Event Manager by registering suspend_event_callback
> +	 * for suspend/shutdown event.
> +	 * If xlnx_register_event() returns -EACCES (Xilinx Event Manager
> +	 * is not available to use) or -ENODEV(Xilinx Event Manager not compiled),
> +	 * then use ipi-mailbox or interrupt method.
> +	 */
> +	ret = xlnx_register_event(PM_INIT_SUSPEND_CB, 0, 0, false,
> +				  suspend_event_callback, NULL);
> +	if (!ret) {
> +		zynqmp_pm_init_suspend_work = devm_kzalloc(&pdev->dev,
> +							   sizeof(struct zynqmp_pm_work_struct),
> +							   GFP_KERNEL);
> +		if (!zynqmp_pm_init_suspend_work) {
> +			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0,
> +					      suspend_event_callback);
> +			return -ENOMEM;
> +		}
> +		event_registered = true;
> +
> +		INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
> +			  zynqmp_pm_init_suspend_work_fn);
> +	} else if (ret != -EACCES && ret != -ENODEV) {
> +		dev_err(&pdev->dev, "Failed to Register with Xilinx Event manager %d\n", ret);
> +		return ret;
> +	} else if (of_find_property(pdev->dev.of_node, "mboxes", NULL)) {
>  		zynqmp_pm_init_suspend_work =
>  			devm_kzalloc(&pdev->dev,
>  				     sizeof(struct zynqmp_pm_work_struct),
> @@ -223,6 +263,10 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>  
>  	ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
>  	if (ret) {
> +		if (event_registered) {
> +			xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback);
> +			event_registered = false;
> +		}
>  		dev_err(&pdev->dev, "unable to create sysfs interface\n");
>  		return ret;
>  	}
> @@ -233,6 +277,8 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
>  static int zynqmp_pm_remove(struct platform_device *pdev)
>  {
>  	sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
> +	if (event_registered)
> +		xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback);
>  
>  	if (!rx_chan)
>  		mbox_free_channel(rx_chan);
> 

Acked-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal