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

From: Michal Simek
Date: Mon Jun 21 2021 - 08:05:19 EST




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@xxxxxxxxxx>
> Signed-off-by: Abhyuday Godhasara <abhyuday.godhasara@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxx>

Thanks,
Michal