[PATCH v3 3/3] drivers: soc: xilinx: Add ZynqMP PM driver

From: Jolly Shah
Date: Tue Sep 11 2018 - 17:35:30 EST


From: Rajan Vaja <rajan.vaja@xxxxxxxxxx>

Add ZynqMP PM driver. PM driver provides power management
support for ZynqMP.

Signed-off-by: Rajan Vaja <rajan.vaja@xxxxxxxxxx>
Signed-off-by: Jolly Shah <jollys@xxxxxxxxxx>
---
drivers/soc/xilinx/Kconfig | 11 ++
drivers/soc/xilinx/Makefile | 1 +
drivers/soc/xilinx/zynqmp_power.c | 230 ++++++++++++++++++++++++++++++++++++++
3 files changed, 242 insertions(+)
create mode 100644 drivers/soc/xilinx/zynqmp_power.c

diff --git a/drivers/soc/xilinx/Kconfig b/drivers/soc/xilinx/Kconfig
index 687c8f3..5025e0e 100644
--- a/drivers/soc/xilinx/Kconfig
+++ b/drivers/soc/xilinx/Kconfig
@@ -17,4 +17,15 @@ config XILINX_VCU
To compile this driver as a module, choose M here: the
module will be called xlnx_vcu.

+config ZYNQMP_POWER
+ bool "Enable Xilinx Zynq MPSoC Power Management driver"
+ depends on PM && ARCH_ZYNQMP
+ default y
+ help
+ Say yes to enable power management support for ZyqnMP SoC.
+ This driver uses firmware driver as an interface for power
+ management request to firmware. It registers isr to handle
+ power management callbacks from firmware.
+ If in doubt, say N.
+
endmenu
diff --git a/drivers/soc/xilinx/Makefile b/drivers/soc/xilinx/Makefile
index dee8fd5..428b9db 100644
--- a/drivers/soc/xilinx/Makefile
+++ b/drivers/soc/xilinx/Makefile
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_XILINX_VCU) += xlnx_vcu.o
+obj-$(CONFIG_ZYNQMP_POWER) += zynqmp_power.o
diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
new file mode 100644
index 0000000..9071948
--- /dev/null
+++ b/drivers/soc/xilinx/zynqmp_power.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Zynq MPSoC Power Management
+ *
+ * Copyright (C) 2014-2018 Xilinx, Inc.
+ *
+ * Davorin Mista <davorin.mista@xxxxxxxxxx>
+ * Jolly Shah <jollys@xxxxxxxxxx>
+ * Rajan Vaja <rajan.vaja@xxxxxxxxxx>
+ */
+
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/suspend.h>
+
+#include <linux/firmware/xlnx-zynqmp.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;
+
+enum pm_suspend_mode {
+ PM_SUSPEND_MODE_FIRST = 0,
+ PM_SUSPEND_MODE_STD = PM_SUSPEND_MODE_FIRST,
+ PM_SUSPEND_MODE_POWER_OFF,
+};
+
+#define PM_SUSPEND_MODE_FIRST PM_SUSPEND_MODE_STD
+
+static const char *const suspend_modes[] = {
+ [PM_SUSPEND_MODE_STD] = "standard",
+ [PM_SUSPEND_MODE_POWER_OFF] = "power-off",
+};
+
+static enum pm_suspend_mode suspend_mode = PM_SUSPEND_MODE_STD;
+
+enum pm_api_cb_id {
+ PM_INIT_SUSPEND_CB = 30,
+ PM_ACKNOWLEDGE_CB,
+ PM_NOTIFY_CB,
+};
+
+static void zynqmp_pm_get_callback_data(u32 *buf)
+{
+ zynqmp_pm_invoke_fn(GET_CALLBACK_DATA, 0, 0, 0, 0, buf);
+}
+
+static irqreturn_t zynqmp_pm_isr(int irq, void *data)
+{
+ u32 payload[CB_PAYLOAD_SIZE];
+
+ zynqmp_pm_get_callback_data(payload);
+
+ /* 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))
+ goto done;
+
+ /* 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);
+ }
+
+done:
+ return IRQ_HANDLED;
+}
+
+/**
+ * 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] == ZYNQMP_PM_SUSPEND_REASON_SYSTEM_SHUTDOWN) {
+ orderly_poweroff(true);
+ } else if (pm_work->args[0] ==
+ ZYNQMP_PM_SUSPEND_REASON_POWER_UNIT_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)
+{
+ char *s = buf;
+ int md;
+
+ for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
+ if (suspend_modes[md]) {
+ if (md == suspend_mode)
+ s += sprintf(s, "[%s] ", suspend_modes[md]);
+ else
+ s += sprintf(s, "%s ", suspend_modes[md]);
+ }
+
+ /* Convert last space to newline */
+ if (s != buf)
+ *(s - 1) = '\n';
+ return (s - buf);
+}
+
+static ssize_t suspend_mode_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int md, ret = -EINVAL;
+ const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+
+ if (!eemi_ops || !eemi_ops->set_suspend_mode)
+ return ret;
+
+ for (md = PM_SUSPEND_MODE_FIRST; md < ARRAY_SIZE(suspend_modes); md++)
+ if (suspend_modes[md] &&
+ sysfs_streq(suspend_modes[md], buf)) {
+ ret = 0;
+ break;
+ }
+
+ if (!ret && md != suspend_mode) {
+ ret = eemi_ops->set_suspend_mode(md);
+ if (likely(!ret))
+ suspend_mode = md;
+ }
+
+ return ret ? ret : count;
+}
+
+static DEVICE_ATTR_RW(suspend_mode);
+
+/**
+ * zynqmp_pm_sysfs_init() - Initialize PM driver sysfs interface
+ * @dev: Pointer to device structure
+ *
+ * Return: 0 on success, negative error code otherwise
+ */
+static int zynqmp_pm_sysfs_init(struct device *dev)
+{
+ return sysfs_create_file(&dev->kobj, &dev_attr_suspend_mode.attr);
+}
+
+/**
+ * zynqmp_pm_probe() - Probe existence of the PMU Firmware
+ * and initialize debugfs interface
+ *
+ * @pdev: Pointer to the platform_device structure
+ *
+ * Return: Returns 0 on success, negative error code otherwise
+ */
+static int zynqmp_pm_probe(struct platform_device *pdev)
+{
+ int ret, irq;
+ u32 pm_api_version;
+
+ const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
+
+ if (!eemi_ops || !eemi_ops->get_api_version || !eemi_ops->init_finalize)
+ return -ENXIO;
+
+ eemi_ops->init_finalize();
+ eemi_ops->get_api_version(&pm_api_version);
+
+ /* Check PM API version number */
+ if (pm_api_version < ZYNQMP_PM_VERSION)
+ return -ENODEV;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return -ENXIO;
+
+ ret = devm_request_irq(&pdev->dev, irq, zynqmp_pm_isr, IRQF_SHARED,
+ dev_name(&pdev->dev), pdev);
+ if (ret) {
+ dev_err(&pdev->dev, "request_irq '%d' failed with %d\n",
+ irq, ret);
+ return ret;
+ }
+
+ 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);
+
+ ret = zynqmp_pm_sysfs_init(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to initialize sysfs interface\n");
+ return ret;
+ }
+
+ return ret;
+}
+
+static const struct of_device_id pm_of_match[] = {
+ { .compatible = "xlnx,zynqmp-power", },
+ { /* end of table */ },
+};
+MODULE_DEVICE_TABLE(of, pm_of_match);
+
+static struct platform_driver zynqmp_pm_platform_driver = {
+ .probe = zynqmp_pm_probe,
+ .driver = {
+ .name = "zynqmp_power",
+ .of_match_table = pm_of_match,
+ },
+};
+module_platform_driver(zynqmp_pm_platform_driver);
--
2.7.4