From: Jolly Shah <jolly.shah@xilinx.com>
To: <matthias.bgg@gmail.com>, <andy.gross@linaro.org>,
        <shawnguo@kernel.org>, <geert+renesas@glider.be>,
        <bjorn.andersson@linaro.org>, <sean.wang@mediatek.com>,
        <m.szyprowski@samsung.com>, <michal.simek@xilinx.com>
CC: <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, Jolly Shah <jollys@xilinx.com>,
        Rajan Vaja <rajanv@xilinx.com>
Subject: [RFC PATCH] drivers: soc: xilinx: Add ZynqMP PM driver
Date: Mon, 8 Jan 2018 14:10:44 -0800
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Add ZynqMP PM driver. PM driver provides power management
support for ZynqMP.

Signed-off-by: Jolly Shah <jollys@xilinx.com>
Signed-off-by: Rajan Vaja <rajanv@xilinx.com>
---
 .../bindings/soc/xilinx/xlnx,zynqmp-pm.txt         |  15 ++
 drivers/soc/Kconfig                                |   1 +
 drivers/soc/Makefile                               |   1 +
 drivers/soc/xilinx/Kconfig                         |   4 +
 drivers/soc/xilinx/Makefile                        |   4 +
 drivers/soc/xilinx/zynqmp/Kconfig                  |  15 ++
 drivers/soc/xilinx/zynqmp/Makefile                 |   1 +
 drivers/soc/xilinx/zynqmp/pm.c                     | 265 +++++++++++++++++++++
 8 files changed, 306 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt
 create mode 100644 drivers/soc/xilinx/Kconfig
 create mode 100644 drivers/soc/xilinx/Makefile
 create mode 100644 drivers/soc/xilinx/zynqmp/Kconfig
 create mode 100644 drivers/soc/xilinx/zynqmp/Makefile
 create mode 100644 drivers/soc/xilinx/zynqmp/pm.c

diff --git a/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt b/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt
new file mode 100644
index 0000000..9cfb40d
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/xilinx/xlnx,zynqmp-pm.txt
@@ -0,0 +1,15 @@
+Xilinx Zynq MPSoC Power Management Device Tree Bindings
+
+The zynqmp-pm node describes the power management configurations.
+
+Required properties:
+ - compatible		: Must contain:  "xlnx,zynqmp-pm"
+ - interrupt-parent	: Interrupt controller the interrupt is routed through
+ - interrupts		: Interrupt specifier
+
+Examples:
+	zynqmp-firmware {
+		compatible = "xlnx,zynqmp-pm";
+		interrupt-parent = <&gic>;
+		interrupts = <0 35 4>;
+	};
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index fc9e980..c07b4a8 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -16,6 +16,7 @@ source "drivers/soc/tegra/Kconfig"
 source "drivers/soc/ti/Kconfig"
 source "drivers/soc/ux500/Kconfig"
 source "drivers/soc/versatile/Kconfig"
+source "drivers/soc/xilinx/Kconfig"
 source "drivers/soc/zte/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index deecb16..abb019a 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ARCH_ROCKCHIP)	+= rockchip/
 obj-$(CONFIG_SOC_SAMSUNG)	+= samsung/
 obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
+obj-$(CONFIG_ARCH_ZYNQMP)	+= xilinx/
 obj-$(CONFIG_SOC_TI)		+= ti/
 obj-$(CONFIG_ARCH_U8500)	+= ux500/
 obj-$(CONFIG_PLAT_VERSATILE)	+= versatile/
diff --git a/drivers/soc/xilinx/Kconfig b/drivers/soc/xilinx/Kconfig
new file mode 100644
index 0000000..190add7
--- /dev/null
+++ b/drivers/soc/xilinx/Kconfig
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier:	GPL-2.0+
+# Kconfig for Xilinx SoCs
+
+source "drivers/soc/xilinx/zynqmp/Kconfig"
diff --git a/drivers/soc/xilinx/Makefile b/drivers/soc/xilinx/Makefile
new file mode 100644
index 0000000..bc9d560
--- /dev/null
+++ b/drivers/soc/xilinx/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier:	GPL-2.0+
+# Makefile for Xilinx SoCs
+
+obj-$(CONFIG_ARCH_ZYNQMP) += zynqmp/
diff --git a/drivers/soc/xilinx/zynqmp/Kconfig b/drivers/soc/xilinx/zynqmp/Kconfig
new file mode 100644
index 0000000..d3c784d
--- /dev/null
+++ b/drivers/soc/xilinx/zynqmp/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier:	GPL-2.0+
+# Kconfig for Xilinx zynqmp SoC
+#
+menu "Zynq MPSoC SoC Drivers"
+	depends on ARCH_ZYNQMP
+
+
+config ZYNQMP_PM
+	bool "Enable Xilinx Zynq MPSoC Power Management"
+	depends on PM
+	help
+	  Say yes to enable power management support for
+	  ZyqnMP SoC. In doubt, say N.
+
+endmenu
diff --git a/drivers/soc/xilinx/zynqmp/Makefile b/drivers/soc/xilinx/zynqmp/Makefile
new file mode 100644
index 0000000..98034f7
--- /dev/null
+++ b/drivers/soc/xilinx/zynqmp/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ZYNQMP_PM) += pm.o
diff --git a/drivers/soc/xilinx/zynqmp/pm.c b/drivers/soc/xilinx/zynqmp/pm.c
new file mode 100644
index 0000000..7178fb5
--- /dev/null
+++ b/drivers/soc/xilinx/zynqmp/pm.c
@@ -0,0 +1,265 @@
+/*
+ * Xilinx Zynq MPSoC Power Management
+ *
+ *  Copyright (C) 2014-2017 Xilinx, Inc.
+ *
+ *  Davorin Mista <davorin.mista@aggios.com>
+ *  Jolly Shah <jollys@xilinx.com>
+ *  Rajan Vaja <rajanv@xilinx.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <linux/compiler.h>
+#include <linux/arm-smccc.h>
+#include <linux/of.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/debugfs.h>
+#include <linux/reboot.h>
+#include <linux/suspend.h>
+#include <linux/firmware/xilinx/zynqmp/firmware.h>
+
+#define DRIVER_NAME	"zynqmp_pm"
+
+/**
+ * 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_STD,
+	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 irqreturn_t zynqmp_pm_isr(int irq, void *data)
+{
+	u32 payload[CB_PAYLOAD_SIZE];
+	const struct zynqmp_eemi_ops *eemi_ops = get_eemi_ops();
+
+	if (!eemi_ops || !eemi_ops->get_callback_data)
+		return IRQ_NONE;
+
+	eemi_ops->get_callback_data(payload);
+
+	if (!payload[0])
+		return IRQ_NONE;
+
+	/* 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;
+}
+
+static const struct of_device_id pm_of_match[] = {
+	{ .compatible = "xlnx,zynqmp-pm", },
+	{ /* end of table */ },
+};
+
+MODULE_DEVICE_TABLE(of, pm_of_match);
+
+/**
+ * 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 = 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 = get_eemi_ops();
+
+	if (!eemi_ops || !eemi_ops->get_api_version)
+		return -ENXIO;
+
+	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 = request_irq(irq, zynqmp_pm_isr, IRQF_SHARED, DRIVER_NAME, 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) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	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");
+		goto error;
+	}
+
+	dev_info(&pdev->dev, "Power management API v%d.%d\n",
+		 ZYNQMP_PM_VERSION_MAJOR, ZYNQMP_PM_VERSION_MINOR);
+
+	return 0;
+
+error:
+	free_irq(irq, 0);
+	return ret;
+}
+
+static struct platform_driver zynqmp_pm_platform_driver = {
+	.probe   = zynqmp_pm_probe,
+	.driver  = {
+			.name             = DRIVER_NAME,
+			.of_match_table   = pm_of_match,
+		   },
+};
+builtin_platform_driver(zynqmp_pm_platform_driver);
+
+/**
+ * zynqmp_pm_init - Notify PM firmware that initialization is completed
+ *
+ * Return:	Status returned from the PM firmware
+ */
+static int __init zynqmp_pm_init(void)
+{
+	const struct zynqmp_eemi_ops *eemi_ops = get_eemi_ops();
+
+	if (!eemi_ops || !eemi_ops->init_finalize)
+		return -ENXIO;
+
+	return eemi_ops->init_finalize();
+}
+
+late_initcall_sync(zynqmp_pm_init);
-- 
2.7.4