[PATCH v2 2/2] drivers: soc: xilinx: Use mailbox IPI callback

From: Rajan Vaja
Date: Fri Nov 22 2019 - 03:45:53 EST


From: Tejas Patel <tejas.patel@xxxxxxxxxx>

Add support for init suspend callback through mailbox IPI callback.

Signed-off-by: Tejas Patel <tejas.patel@xxxxxxxxxx>
Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
---
drivers/soc/xilinx/zynqmp_power.c | 119 +++++++++++++++++++++++++++++++++-----
1 file changed, 106 insertions(+), 13 deletions(-)

diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
index 1b9d144..d572d2e 100644
--- a/drivers/soc/xilinx/zynqmp_power.c
+++ b/drivers/soc/xilinx/zynqmp_power.c
@@ -2,7 +2,7 @@
/*
* Xilinx Zynq MPSoC Power Management
*
- * Copyright (C) 2014-2018 Xilinx, Inc.
+ * Copyright (C) 2014-2019 Xilinx, Inc.
*
* Davorin Mista <davorin.mista@xxxxxxxxxx>
* Jolly Shah <jollys@xxxxxxxxxx>
@@ -16,6 +16,20 @@
#include <linux/suspend.h>

#include <linux/firmware/xlnx-zynqmp.h>
+#include <linux/mailbox/zynqmp-ipi-message.h>
+
+/**
+ * struct zynqmp_pm_work_struct - Wrapper for struct work_struct
+ * @callback_work: Work structure
+ * @args: Callback arguments
+ */
+struct zynqmp_pm_work_struct {
+ struct work_struct callback_work;
+ u32 args[CB_ARG_CNT];
+};
+static struct zynqmp_pm_work_struct *zynqmp_pm_init_suspend_work;
+static struct mbox_chan *rx_chan;
+static const struct zynqmp_eemi_ops *eemi_ops;

enum pm_suspend_mode {
PM_SUSPEND_MODE_FIRST = 0,
@@ -31,7 +45,6 @@ static const char *const suspend_modes[] = {
};

static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
-static const struct zynqmp_eemi_ops *eemi_ops;

enum pm_api_cb_id {
PM_INIT_SUSPEND_CB = 30,
@@ -68,6 +81,53 @@ static irqreturn_t zynqmp_pm_isr(int irq, void *data)
return IRQ_HANDLED;
}

+static void ipi_receive_callback(struct mbox_client *cl, void *data)
+{
+ struct zynqmp_ipi_message *msg = (struct zynqmp_ipi_message *)data;
+ u32 payload[CB_PAYLOAD_SIZE];
+ int ret;
+
+ memcpy(payload, msg->data, sizeof(msg->len));
+ /* First element is callback API ID, others are callback arguments */
+ if (payload[0] == PM_INIT_SUSPEND_CB) {
+ 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);
+
+ /* Send NULL message to mbox controller to ack the message */
+ ret = mbox_send_message(rx_chan, NULL);
+ if (ret)
+ pr_err("IPI ack failed. Error %d\n", ret);
+ }
+}
+
+/**
+ * zynqmp_pm_init_suspend_work_fn - Initialize suspend
+ * @work: Pointer to work_struct
+ *
+ * Bottom-half of PM callback IRQ handler.
+ */
+static void zynqmp_pm_init_suspend_work_fn(struct work_struct *work)
+{
+ struct zynqmp_pm_work_struct *pm_work =
+ container_of(work, struct zynqmp_pm_work_struct, callback_work);
+
+ if (pm_work->args[0] == SUSPEND_SYSTEM_SHUTDOWN) {
+ orderly_poweroff(true);
+ } else if (pm_work->args[0] == SUSPEND_POWER_REQUEST) {
+ pm_suspend(PM_SUSPEND_MEM);
+ } else {
+ pr_err("%s Unsupported InitSuspendCb reason code %d.\n",
+ __func__, pm_work->args[0]);
+ }
+}
+
static ssize_t suspend_mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -119,6 +179,7 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
{
int ret, irq;
u32 pm_api_version;
+ struct mbox_client *client;

eemi_ops = zynqmp_pm_get_eemi_ops();
if (IS_ERR(eemi_ops))
@@ -134,17 +195,46 @@ static int zynqmp_pm_probe(struct platform_device *pdev)
if (pm_api_version < ZYNQMP_PM_VERSION)
return -ENODEV;

- irq = platform_get_irq(pdev, 0);
- if (irq <= 0)
- return -ENXIO;
-
- ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, zynqmp_pm_isr,
- IRQF_NO_SUSPEND | IRQF_ONESHOT,
- dev_name(&pdev->dev), &pdev->dev);
- if (ret) {
- dev_err(&pdev->dev, "devm_request_threaded_irq '%d' failed "
- "with %d\n", irq, ret);
- return ret;
+ 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),
+ GFP_KERNEL);
+ if (!zynqmp_pm_init_suspend_work)
+ return -ENOMEM;
+
+ INIT_WORK(&zynqmp_pm_init_suspend_work->callback_work,
+ zynqmp_pm_init_suspend_work_fn);
+ client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
+ if (!client)
+ return -ENOMEM;
+
+ client->dev = &pdev->dev;
+ client->rx_callback = ipi_receive_callback;
+
+ rx_chan = mbox_request_channel_byname(client, "rx");
+ if (IS_ERR(rx_chan)) {
+ dev_err(&pdev->dev, "Failed to request rx channel\n");
+ return IS_ERR(rx_chan);
+ }
+ } else if (of_find_property(pdev->dev.of_node, "interrupts", NULL)) {
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return -ENXIO;
+
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ zynqmp_pm_isr,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ dev_name(&pdev->dev),
+ &pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "devm_request_threaded_irq '%d' "
+ "failed with %d\n", irq, ret);
+ return ret;
+ }
+ } else {
+ dev_err(&pdev->dev, "Required property not found in DT node\n");
+ return -ENOENT;
}

ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);
@@ -160,6 +250,9 @@ static int zynqmp_pm_remove(struct platform_device *pdev)
{
sysfs_remove_file(&pdev->dev.kobj, &dev_attr_suspend_mode.attr);

+ if (!rx_chan)
+ mbox_free_channel(rx_chan);
+
return 0;
}

--
2.7.4